IV Fluids, Blood

Which of the following is not an effect of sodium chloride 0.9% infusion A. Increase GFR B. Impair renal handling of bicarbonate C. Postoperative bowel dysmotility D. Increase rate of excretion of sodium and water balance

A & D - Hyperchloremia may also have a significant impact on renal function. This is thought to be due in part to the impact of excess renal reabsorption of chloride on renal arteriolar vascular resistance, leading to a decrease in glomerular filtration rates.31,37 Hyperchloremia may also impair renal handling of bicarbonate. The increased sodium load introduced by large volumes of 0.9% saline has been shown to cause increased salt and water retention, hemodilution, and interstitial edema well into the postoperative period. Studies have demonstrated that the administration of 2 L of 0.9% saline to healthy volunteers contributes to a positive sodium and water balance that takes 2 days to excrete.11,38 This duration may be significantly prolonged in surgical patients.11,15 NS has a dose-dependent association with renal impairment and postoperative bowel dysmotility; these effects may be more pronounced in patients with preexisting renal disease. (Elisha 349-350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

These are not predictive of volume responsiveness A. MAP B. CVP C. UO D. SVV

A, B, C A significant limitation of historical methods that are associated with fluid administration is the reliance on static and nonspecific indices of fluid balance such as MAP, CVP, and urine output. Despite the value of these measures in the context of standard monitoring and basic vital support, they are not predictive of volume responsiveness.2 MAP is an unreliable index of volume status; hypotensive patients may have a "relative hypovolemia" associated with altered vascular tone or impaired cardiac function despite adequate or excessive intravascular volume. Conversely, patients who are dependent on adequate preload may have intact compensatory mechanisms that preserve normotension.30 Historic approaches often rely on fluid volume to treat hypotension, regardless of the cause (e.g., volume preloading to treat or prevent hypotension related to neuraxial sympathectomy, bolus fluids on induction of anesthesia to compensate for myocardial depression and vasodilation).56 CVP is largely dependent on venous return; baseline values may also be altered in patients with right heart impairment, severe pulmonary disease, valvular disease, and portal hypertension.1 Studies involving critically ill patients, including those with sepsis, demonstrated that only half of patients with low CVP values are fluid-responsive.78 Therefore the use of CVP as a fluid administration target leads to an extraordinarily high incidence of fluid overload in patients who may not be able to compensate for the increased vascular volume.30 Reliance on urine output as a measurement of volume status is not an accurate target for fluid administration because it can be impacted by a myriad of factors, including enhanced neuroendocrine responses.79 Furthermore, volume administration in anesthetized oliguric patients with high levels of circulating ADH

Fluid management techniques that continue to account for the third space have been shown to result in poor clinical outcomes and gross fluid accumulation of up to __ kg of perioperative weight gain A. 10 B. 20 C. 30 D. 40

A. 10 - The concept of the "third space" was introduced in the 1960s as a nonfunctional component of the ECV. Prior to understanding the role of neuroendocrine mechanisms in the stress response, the original study hypothesized that redistribution of extracellular fluids (ECFs) contributed to the tendency of postoperative patients to retain sodium and water.76 By excluding fluid administration and utilizing isotope tracers to tag plasma components, the investigators hoped to identify the mechanisms of fluid redistribution. They measured suction contents, specimens, sponges, and laparotomy packs for isotopes and hemoglobin. They ultimately concluded that there was a measurable deficit in functional ECV (volume subject to transcapillary fluid dynamics) not attributable to blood loss, hence the third space.76 The third space concept became a justification for the use of liberal perioperative fluid administration to compensate for redistribution of ECV into this nonfunctional space.17 Multiple studies have since attempted to quantify the third space with the use of various tracers. Despite some results that supported a functional ECV deficit, none of these studies were able to identify the anatomical location of this transcellular fluid reservoir.18 Nonetheless, the practice of replacing third space deficits became a doctrine of historical anesthetic practice.77 Fluid management techniques that continue to account for the third space have been shown to result in poor clinical outcomes and gross fluid accumulation of up to 10 kg of perioperative weight gain. - The tendency of historical approaches to support liberal fluid administration continues in the recommendations for managing acute blood loss. The 3 : 1 ratio of crystalloid solutions to estimated blood loss (EBL) was introduced to preserve intravascular volume while ac

These HES are the highest molecular weight solutions (> 450 kDa) and often have the greatest substitution ratios (0.6-0.7) A. 1st generation B. 2nd generation C. 3rd generation D. 4th generation

A. 1st generation - The clinical impact of HES has been studied extensively because of the prevalence of their use in perioperative and critical care settings.11 First-generation HES (hetastarches and hexastarches) are the highest molecular weight solutions (> 450 kDa) and often have the greatest substitution ratios (0.6-0.7).36,41 These solutions are associated with dose-dependent coagulopathy because of hemodilution and binding of clotting factors, interference with platelet adhesion, and alterations in plasma viscosity.1,11 HES can also accumulate to form interstitial colloid deposits in subcutaneous and other organ tissues leading to severe pruritus and nephrotoxicity.10,11,31 This effect was originally thought to be associated with the prolonged metabolic profile of first-generation HES, but studies have demonstrated that this effect occurs across all generations of HES. Second-generation solutions, pentastarches, are medium-weight solutions (200-260 kDa) with a substitution ratio of 0.5. Third-generation HES are low molecular-weight tetrastarches (70-130 kDa) with a substitution ratio of 0.4 (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

• 0-10 kg: 4 mL/kg per hr • 11-20 kg:4 mL/kg per hr for the first 10 kg; 2 mL/kg per hr for every kg >10 • >20 kg: 4 mL/kg per hr for the first 10 kg; 2 mL/kg per hr for the next 10 kg; 1 mL/kg per hr for every kg >20 A. 4-2-1 calculation B. Estimated fluid deficit C. Guidelines for replacement for surgical losses D. Recommendation for replacement of blood loss

A. 4-2-1 calculation -

This was used in combination with estimates of fasting deficit, formulaic assessments of surgical insensible losses, and calculated ratios for replacement of blood loss A. 4-2-1 calculation B. Estimated fluid deficit C. Guidelines for replacement for surgical losses D. Recommendation for replacement of blood loss

A. 4-2-1 calculation - Fluid management techniques have relied on formulaic fixed-volume approaches to standardize fluid administration for all surgical patients, regardless of volume status at onset of surgery, myocardial and renal function, and vascular tone. These traditional methods often involved uniform calculations to assess the fluid requirement of a given patient. Perhaps the most common of these was the 4-2-1 calculation; this was used in combination with estimates of fasting deficit, formulaic assessments of surgical insensible losses, and calculated ratios for replacement of blood loss (Box 21.1).66 The driving concept behind many of these approaches was the theory that fasting patients incurred a preoperative "fluid debt" and required volume preloading to help maintain physiologic stability and homeostasis.13 Scientific evidence challenges this assessment because it does not account for cardiovascular and renal function in individual patients, nor does it consider the true impact of fasting in elective surgical patients.17 A 2008 study evaluated the impact of preoperative fasting on blood and plasma volumes in gynecologic surgery patients without cardiac disease who had not received mechanical bowel preparations. Measurements of tagged erythrocytes and tracer-dilution analysis of total plasma volume demonstrated that patients had normal circulating intravascular volumes after 10 hours of preoperative fasting.67 The routine use of preemptive fluid administration to correct perceived fasting deficits often contributed to overload-associated perioperative complications.16 Furthermore, current knowledge indicates that prophylactic volume administration in euvolemic patients is an antiquated practice with substantial risk of disrupting the endothelial glycocalyx and contributing to pathologic fluid overload (El

This is is the intravascular blood pressure, driven by the force of the CO and impacted by vascular tone. A. Capillary hydrostatic pressure (Pc) B. Interstitial fluid pressure (Pif) C. Plasma oncotic pressure (mp) D. Interstitial oncotic pressure (nif)

A. Capillary hydrostatic pressure (Pc) - Fluid exchange between the extracellular compartments is largely dependent on the Starling forces, four transcapillary pressures whose gradients dictate direction of fluid movement across the capillary epithelium.19 Capillary hydrostatic pressure (Pc) is the intravascular blood pressure, driven by the force of the CO and impacted by vascular tone. (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Which of the following are the preferable situation for infusion of crystalloids A. Dehydration B. Fasting states C. Chronic GI losses D. Ologuria E. Hypermetabolic conditions

A. Crystalloids - Crystalloids are aqueous electrolyte solutions that have been a mainstay of volume resuscitation in surgical patients for over a century.17,30,31 Crystalloid infusions are preferable for resuscitation of dehydration conditions (conditions of TBW loss leading to plasma hypertonicity) such as prolonged fasting states, active gastrointestinal losses, polyuria, and hypermetabolic conditions.32 The administration of isotonic crystalloid solutions under these circumstances contributes to the hydration of the entire ECV, restoring water and electrolyte homeostasis to both intravascular and interstitial spaces for normal cellular processes. The use of crystalloids to replace active intravascular losses in the perioperative setting is beneficial for providing immediate restoration of circulating vascular volume, preservation of microcirculatory flow, decrease in hormone-mediated vasoconstriction, and correction of plasma hyperviscosity associated with acute hemorrhage. (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

These are among the oldest artificial colloids, and they possess high-molecular weight polymers (40-70 kDa) derived from bacterial metabolism of sucrose. These compounds are known to cause acute renal failure by multiple mechanisms. They have coagulopathic effects as demonstrated by dextran's impairment of von Willebrand factor, activation of plasminogen, and interference with platelet aggregation. They are highly allergenic and are no longer available in many countries because of their propensity to induce anaphylaxis. A. Dextran B. Albumin C. Gelatin D. Hydroxyethyl starches

A. Dextran - Dextrans are among the oldest artificial colloids, and they possess high-molecular weight polymers (40-70 kDa) derived from bacterial metabolism of sucrose. They were first manufactured in the 1940s.31,41,46 They are markedly hyperosmolar and have a half-life of roughly 6 to 12 hours.36,46 These compounds are known to cause acute renal failure by multiple mechanisms, including indirect hyperosmotic renal injury and direct renal tubular damage as a result of accumulation.15,36,41 They have coagulopathic effects as demonstrated by dextran's impairment of von Willebrand factor, activation of plasminogen, and interference with platelet aggregation.41 Dextrans can adhere to the surface of platelets and red blood cells and interfere with cross-matching of blood products.46 Dextrans were briefly popular in microvascular surgery settings for their antithrombotic effects, but they have largely been abandoned for this use and as plasma volume expanders resulting from their unfavorable risk ratio.15,36 They are highly allergenic and are no longer available in many countries because of their propensity to induce anaphylaxis (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Albumin molecules bind ions, which increase plasma osmolality and intravascular volume; this phenomenon is known as the A. Donnan effect B. Double barrier effect C. Second fluid effect D. Venturi effect

A. Donnan effect - Albumin is a carrier for a number of protein-bound ionic substances, including drugs and their metabolites, electrolytes, enzymes, and hormones. In the presence of hypoalbuminemia, the administration of albumin may be advised.20 Because of its negative electrostatic charge, albumin molecules bind ions, which increase plasma osmolality and intravascular volume; this phenomenon is known as the Donnan effect.19 One of the more commonly cited outcome assessments associated with albumin is the Saline Versus Albumin Fluid Evaluation (SAFE) study, a trial of nearly 7000 critically ill patients, who were randomized to receive 0.9% saline or 4% albumin solutions. The study demonstrated that no difference in clinical outcomes existed, except in cases of neurotrauma, where patients in the albumin cohort had a higher incidence of mortality. (Elisha 351) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

What are the primary anion and cation in the following compartment A. ECV B. ICV

A. ECV= Anion= CL, Cation= Na ICV Anion=Ph, Cation= K - The primary cation of the ECV is sodium and the primary anion is chloride. Potassium is the primary cation of the ICV and phosphate the primary anion.10,12 The resting membrane gradient for these electrolytes is maintained by the sodium-potassium adenosine triphosphate enzyme (Na + K + ATPase) in the cell membrane that uses cellular energy to actively transport sodium ions into the ECV.12,13 The cell membrane is permeable to water and as a result, the ICV and ECV maintain a state of osmotic equilibrium despite their varied solute composition.12,13 The daily fluid volume required to maintain TBW homeostasis in a healthy adult who is normothermic with standard metabolic function is approximately 25 to 35 mL/kg per day (~2-3 liters per day). (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Positive net filtration favors A. Fluid exudation into the tissue B. Fluid absorption into the vasculature

A. Fluid exudation into the tissue - Positive net filtration favors fluid exudation into the tissues; negative net filtration favors fluid absorption into the vasculature.10,19 Net filtration tends to be slightly positive at the arterial end of capillaries and slightly negative at the venous end.19,20 The overall balance of filtration pressures within the capillaries of the entire body is slightly positive such that a small percentage of intravascular volume is constantly filtered into the interstitial space at a rate of approximately 2 mL/min under normal physiologic conditions.19,20 This volume is returned to the intravascular space via the lymphatic system. Under euvolemic conditions, net fluid filtration is roughly equal to lymphatic flow (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

The _________ in pleural pressure of mechanically ventilated patients during inspiration augments left ventricle (LV) filling A. Increase B. Decrease

A. Increase - The increase in pleural pressure of mechanically ventilated patients during inspiration augments left ventricle (LV) filling as a result of compression of pulmonary veins and pleural restriction of right ventricle (RV) filling (leading to enhanced LV compliance); this contributes to an increase in SV. During expiration SV falls when the reduced RV preload has had time to transit through the heart.102 The degree of variation in SV is more prominent in during hypovolemia due to (a) increased intrathoracic pressure from positive pressure ventilation decreases RV filling, (b) greater inspiratory impact on RV afterload if alveolar pressure exceeds pulmonary arterial and venous pressures impeding RV ejection, and (c) greater ventricular contractility in response to the LV preload "bolus" if the patient is on the ascending portion of the Frank-Starling curve (Elisha 356) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

During periods that result in hypovolemia or hemorrhage, __________ Pc favors absorption and supplies an autotransfusion of fluid volume from the interstitial space into the intravascular space. A. Increased B. Decreased

A. Increased - During periods that result in hypovolemia or hemorrhage, decreased Pc favors absorption and supplies an autotransfusion of fluid volume from the interstitial space into the intravascular space. Conversely, hypervolemia or vascular overload may cause a marked increase in Pc and a dilutional decrease in πp that favor filtration, overfilling the interstitial space, and overwhelming the lymphatic system. The development of interstitial edema is a primary cause of tissue congestion, capillary collapse, loss of waste removal and nutrient exchange capabilities, decreased microcirculatory flow, and tissue ischemia. (Elisha 352) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

These are known to be very effective at reducing HPA-mediated stress responses A. Opioids B. Neuraxial anesthesia C. Clonidine D. Dexmedetomidine

A. Opioids - Anesthetic interventions may help mitigate many of these responses. High-dose opioids are known to be very effective at reducing HPA-mediated stress responses; however, enhanced recovery strategies discourage the administration of large doses of opioids.63 Neuraxial anesthesia helps to mitigate spinal cord transmission of autonomic afferent impulses, which would otherwise stimulate HPA. This effect is most pronounced in procedures of the lower extremities and pelvis.57,58 Low-dose clonidine is being studied for its potential as a premedication to provide opioid-sparing analgesic effects and to attenuate the hemodynamic stress of laparoscopy.63,64 Anesthetic agents also exert significant impacts on perfusion. Propofol infusion may provide some regional vasodilatory effects, but these are mitigated by a dose-dependent decrease in myocardial contractility.57 Volatile anesthetic agents are also known to reduce myocardial contractility, but this effect is attenuated in most modern agents (isoflurane, desflurane, and sevoflurane) by enhanced reflex sympathetic activity. These agents do contribute to a dose-dependent reduction in myocardial contractility and SVR that can manifest as significant hypotension.65 The concept of goal-directed fluid management is intricately connected to physiologic changes during surgery. Judicious and timely administration of fluids and vasoactive support to meet defined perfusion targets has been shown to support oxygen balance and mitigate the body's neuroendocrine response to surgical stress.27 Furthermore, maintenance of euvolemia throughout the perioperative period helps to preserve the glycocalyx and its associated microvascular functions (Elisha 352) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is an important regulator of physiologic sodium hemostasis A. RAAS B. ADH pathway C. ANP pathway

A. RAAS - The RAAS is an important regulator of physiologic sodium hemostasis.12 In response to hypotension (as detected by intracardiac and renal afferent arteriole baroreceptors) and systemic sympathetic stimulation, the juxtaglomerular cells of the kidney release the enzyme renin. The interaction of circulating renin with the precursor angiotensinogen causes cleaving of angiotensinogen to the active substance angiotensin I. Angiotensin I exerts local vasoconstrictor activity, but its primary role is as a precursor for the more potent angiotensin II. This change occurs in the lungs as a result of angiotensin converting enzyme (ACE) acting as a catalyst for the conversion of angiotensin I to angiotensin II. Angiotensin II is a potent vasoconstrictor and directly stimulates the renal tubules to reabsorb sodium and water. It also causes the adrenal cortex to release aldosterone, which further stimulates sodium and water retention by the kidney (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

The most commonly administered intravenous fluid worldwide but is the least physiologic A. Sodium chloride B. Lactated Ringer C. Plasmalyte

A. Sodium chloride - Sodium chloride is the original crystalloid solution 0.9% saline solution, known as normal saline (NS)," and is currently the most commonly administered intravenous fluid worldwide.13,14,31,34,35 NS was determined to be a physiological solution over a century ago based on in vitro erythrocyte studies comparing the effects of a 0.9% saline infusion with those of a 0.6% solution; the term NS persists today.31 However, of all of the isotonic crystalloid preparations available for fluid resuscitation, 0.9% saline is the least physiologic (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

According to the ERAS protocol, which of the following is at the highest risk for hypovolemia and dehydration A. Clear fluids up to 2 hours B. NPO 8 prior to surgery C. Using mechanical bowel preparation D. Carbohydrate drink 2 hours

B & C - Optimal perioperative fluid management is an essential component of the ERAS pathway and important for improving postsurgical outcomes. The current ASA practice standard for preoperative surgical patients is nil per os (NPO) for at least four hours. This practice renders the patient in a relatively dehydrated state prior to surgery.117,118 The goal of ERAS during the preoperative period is for the patient to arrive in the operating room in a euvolemic state.119,120 A Cochrane review in demonstrated substantial evidence that allowing clear fluids up to 2 hours prior to surgery during the preoperative fasting period does not increase complications.121,122 The current practice standard for prolonged fasting, generally 8 hours prior to surgery, has not demonstrated a reduction in gastric contents nor an increase in gastric fluid pH.122 Miller et al.119 recommend avoiding the routine use of mechanical bowel preparation (MBP) prior to colorectal surgery as an additional means of preventing dehydration on the day of surgery. The administration of MBP for colorectal surgical patients can vary based on the surgeon's preference. The existing evidence indicates that MBP results in fluid shifts and increases postoperative morbidity.122-124 Reducing NPO time by implementing two ERAS interventions of supplying a carbohydrate drink up to 2 hours prior to surgery, and eliminating MBP, are proven methods that have contributed to improved optimization of the patient during the preoperative phase.123,124 Supplying a carbohydrate drink 2 hours prior to surgery has the added benefit of maintaining adequate preoperative glucose and insulin levels, thereby reducing preoperative thirst, hunger, and anxiety levels experienced by the patient.122 Decreasing NPO time results in a reduced state of relative dehydration prior to surgery. Thu

Which of the following is not a limitation of pulse contour analysis A. Spontaneous ventilation B. Large tidal volumes C. Open chest D. Sustained arrhythmias E. PEEP F. Left heart dysfunction

B & F

colloids may be the preferred solution for A. Euvolemic patients B. Patients with intact glycocalyx undergoing acute volume loss C. Patients with sepsis D. Patient with hyperglycemia

B. - A critical theme in the administration of colloid solutions is the careful consideration of endothelial integrity. As a result of the targeted expansion of the intravascular space, colloids may be the preferred solution for replacement of circulating blood volume in patients with intact endothelial glycocalyx undergoing acute volume losses.16,42 However, the use of albumin and other colloids in patients with endothelial injuries may lead to pulmonary edema and other end-organ complications.23 Furthermore, the administration of colloid solutions to patients who are euvolemic has been known to contribute to ANP-mediated hypervolemic endothelial disruption.16,25,54,55If patients have clinical conditions that are likely to precipitate endothelial injury such as hyperglycemia or sepsis, colloid solutions should be avoided.16,43 A Cochrane review of the risks and benefits of crystalloids and colloids in critically ill patients concluded that there is no benefit to the administration of colloids as compared to crystalloids, and that their cost does not justify their use in critically ill patients.29,36,43 Evidence suggests an acceptable safety profile for albumin alone; the use of HES remains controversial. However, the cost of albumin may not justify its use except in certain circumstances.35 The use of albumin in small allotments is still warranted in the context of goal-directed administration to volume-responsive patients - The majority of data on patient outcomes with administration of colloid solutions is based on 0.9% saline. Further research is needed on the clinical impacts of colloid suspensions in balanced salt solutions. A prospective study of 760 intensive care patients examined the relationship between chloride-rich solutions (0.9% saline, 4% gelatin, and 4% albumin) and chloride-restricted solutions (balan

daily water fluctuation only represents approximately ___% of TBW A. 0.1 B. 0.2 C. 0.3 D. 0.4

B. 0.2 - These mechanisms combine with many other complex renal, hormonal, vascular, and metabolic processes to carefully maintain fluid and electrolyte balance.15 In the healthy adult, inputs such as water and electrolyte intake (nutrition and free water intake) are maintained within such narrow limits (sweat, respiratory losses, gastrointestinal losses, and urine output) that daily water fluctuation only represents approximately 0.2% of TBW (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

In PGDT, what is the recommended fluid bolusing volume to assess the patient's hemodynamic responsiveness to fluids A. 100-150 ml B. 200-250 ml C. 250-500 ml D. 500-1000 ml

B. 200-250 ml - The success of PGDT in improving clinical outcomes is largely the result of its algorithmic approach evaluating fluid responsiveness, identifying appropriate support measures when fluid is not indicated, and optimizing oxygen transport balance.30 PGDT protocols often begin with a baseline assessment of target hemodynamic measures, followed by the administration of a small volume fluid bolus (200-250 mL) to assess the patient's position along the Frank-Starling curve. By integrating fluid administration triggers, small volume boluses, and defined targets for cessation of fluid therapy, PGDT protocols provide important clinical end-points for assessing response to fluid intervention and preventing vascular overload. These guidelines also provide prompts for consideration of vasoactive or inotropic support. Most protocols promote constant reassessment of factors such as preload responsiveness and oxygen delivery (every 5-10 minutes). This aids in the timely administration of fluid and other interventions that have been shown to have a tremendous impact on preserving both endothelial and global perfusion (Elisha 357-358) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This pathway functions primarily to regulate water balance A. RAAS B. ADH pathway C. ANP pathway

B. ADH pathway - The ADH pathway functions primarily to regulate water balance. In response to even minute increases in serum osmolality (as detected by osmoreceptors in the hypothalamus), the posterior pituitary gland releases ADH, which causes aquaporin channels within the kidney to transiently reabsorb large quantities of water. This helps preserve circulating volume and contributes to a tremendous increase in urine concentration and osmolality.12,19 ADH also plays an important role in preserving blood pressure by acting as a potent arterial vasoconstrictor. Decreases in circulating blood volume (as detected by baroreceptors in the atria, carotid body, and aorta) stimulate this hormones release, although this mechanism is much less sensitive than osmolality-mediated secretion.19 The detection of increased serum osmolality also causes the hypothalamus to stimulate thirst. (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Sympathetic stimulation, in combination with hyperosmolar conditions, triggers this pathway A. RAAS B. ADH pathway C. ANP pathway

B. ADH pathway - The physiological stimulation associated with surgery also causes the release of catecholamines. Surgical trauma causes direct stimulation of sympathetic nerves, which trigger a substantial release of catecholamines from the adrenal medulla, causing sympathetic nervous system effects such as increased heart rate, increased systemic vascular resistance (SVR), microcirculatory vasoconstriction, which results in increased basal metabolic rate, and increased oxygen demand.19 Sympathetic stimulation, in combination with hyperosmolar conditions, triggers the release of ADH and causes vasoconstriction, reabsorption of water, and potassium excretion.57 Depending on the magnitude of the surgical trauma and the resulting hemodynamic changes, this release may continue for hours postoperatively. (Elisha 351) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is a fractionated blood product produced from pooled human plasma. It has a molecular weight of 65 to 69 kDa and is heat-treated to inactivate pathogens and eliminate the risk of disease transmission. A. Dextran B. Albumin C. Gelatin D. Hydroxyethyl starches

B. Albumin - Albumin is a fractionated blood product produced from pooled human plasma. It has a molecular weight of 65 to 69 kDa and is heat-treated to inactivate pathogens and eliminate the risk of disease transmission.15,16,41 Commercially prepared albumin solutions were developed in the mid-1940s as plasma volume expanders for use in military trauma settings.31 The use of albumin in these settings was preferred for rapid restoration of circulating volume in active loss situations where transfusion was not readily available. Albumin is often utilized in modern-day anesthetic practice as a volume expander in circumstances of active loss not requiring transfusion.43 Small volumes of albumin provide a greater degree of intravascular resuscitation as compared to equal or greater volumes of crystalloid. Albumin is often utilized in goal-directed approaches to reduce complications associated with tissue edema.13,23 However, it is significantly more costly than other colloid solutions.36 Albumin preparations may also cause anaphylaxis (Elisha 351) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Aside from RBC, this is the only naturally-occurring colloid solution available for infusion A. Dextran B. Albumin C. Gelatin D. Hydroxyethyl starches

B. Albumin - Colloids are suspensions of high-molecular weight molecules in electrolyte solutions that produce intravascular volume expansion by directly increasing πp and interacting with the endothelial glycocalyx to decrease transcapillary filtration.11,30 Because of their effectiveness as plasma volume expanders, colloid solutions are often used perioperatively for their fluid sparing effects compared to crystalloids.31,36 Aside from packed red blood cells, albumin is the only naturally-occurring colloid solution available for infusion; a variety of synthetic colloids are also available worldwide.45 Colloid solutions are classified by molecular weight, concentration, and half-life. (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

The primary goal for PGDT is to maintain oxygen transport balance by optimizing ___ and to minimize ____ A. VO2; DO2 B. DO2; VO2

B. DO2; VO2 - The use of oxygen transport measures as targets for PGDT has long been known to impact survival rates in high-risk and critically ill patients.5 Measures of tissue oxygenation evaluate global tissue oxygen balance with measurement of arterial, mixed venous, central venous blood gases and calculation of oxygen consumption (VO2) and delivery (DO2). Integrated invasive technologies combine invasive lines (PAC, central venous catheter, arterial line) with software inputs of blood gas data to calculate tissue oxygenation measures. The primary goal for PGDT is to maintain oxygen transport balance by optimizing DO2 (fluid optimization, preservation of CO and microcirculatory flow, transfusion) and to minimize VO2 (opioids, β-blockers, maintenance of normothermia).109-111 Active blood loss during surgery causes an imbalance in oxygen transport through loss of both circulating volume and oxygen carrying capacity. The judicious administration of packed red blood cells to optimize DO2 is an important and often controversial consideration in perioperative fluid management. (Elisha 357) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

By binding to circulating plasma albumin, the glycocalyx also helps to preserve capillary oncotic pressure and decrease capillary permeability to water, thus modulating the impact of plasma hydrostatic pressure on net filtration and is known as A. Ventilation effect B. Double barrier effect C. Second fluid effect D. Venturi effect

B. Double barrier effect - Ranging from 0.1 to 1.2 micrometers (mcm) in diameter, the glycocalyx is composed of a backbone matrix of glycoproteins, polysaccharides, and hyaluronic acid that bind to ionic side chains and plasma proteins to create a physiologically active barrier within the vascular space.11,16,25 This dynamic barrier ionically repels negatively charged polar compounds in addition to blood components, to create a zone of exclusion between the surface of the glycocalyx and the center of the vessel, aiding in the prevention of blood component adhesion to the vascular wall and augmenting laminar blood flow.25 By binding to circulating plasma albumin, the glycocalyx also helps to preserve capillary oncotic pressure and decrease capillary permeability to water, thus modulating the impact of plasma hydrostatic pressure on net filtration.24,25 This regulating function has been described as the double barrier effect11,13 and it has led to the development of a revised Starling equation as follows - where πsg is the oncotic pressure in the subglycocalyx space between the endothelium and the glycocalyx. Furthermore, the glycocalyx plays an important role in modulating inflammatory processes. This space is thought to contain inflammatory mediators whose binding sites are enclosed by the matrix, thus helping prevent leukocyte adhesion except in circumstances of acute inflammation or endothelial damage.25 Other functions of the glycocalyx include scavenging of free radicals, binding and activation of anticoagulation factors, and signal transduction that helps regulate local vasoactive responses to mechanical stress (Elisha 348) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is a proactive, multimodal, patient management pathway aimed at improving surgical outcomes. A. PGDT B. ERAS C. NIHS D. CRAP

B. ERAS - Optimal perioperative fluid replacement and management is a fundamental component of fast track programs such as Enhanced Recovery after Surgery (ERAS). ERAS is a proactive, multimodal, patient management pathway aimed at improving surgical outcomes. Protocols for ERAS incorporate best practices that are designed to provide optimal fluid therapy, reduce the profound stress response attributed to surgery, promote non-opioid postoperative pain modalities, and maintain baseline organ function post procedure. Ultimately, the goals for the ERAS pathway for major surgical procedures is to decrease postoperative complications, to accelerate recovery after surgery, and to promote early mobilization and discharge from hospitalization.112 A growing body of evidence supports the ERAS pathway based upon documented improvements with postoperative outcomes and the overall decrease in health care costs associated with surgery.113 A colorectal surgeon from Denmark, Henrik Kehlet, was the first to coin the concept of enhanced recovery in the 1990s when he asked the simple question, "why is the patient still in the hospital after surgery?" He determined the causes were multifactorial, yet he concluded that the common issues faced by postoperative patients were ultimately caused by delays in both gut function and physical mobility after surgery.114 Based upon these observations, protocols were developed that were aimed at addressing the issues that contribute to prolonged postoperative convalescence, and promote interventions that facilitate an improved state of health. - Enhanced Recovery after Surgery was initially developed for colon resection surgery; however enhanced recovery principles are now being used for various surgical procedures including abdominal vascular surgeries, esophagectomy, pancreatectomy, gastric resectio

This is the hydrostatic pressure of the interstitial space. A. Capillary hydrostatic pressure (Pc) B. Interstitial fluid pressure (Pif) C. Plasma oncotic pressure (mp) D. Interstitial oncotic pressure (nif)

B. Interstitial fluid pressure (Pif) - Relative to atmospheric pressure, Pif of most tissues is slightly negative; this is thought to be due to the contraction of lymphatic vessels in the interstitium.19-21 Rigid or encapsulated tissues of the kidneys, brain, bone marrow, and skeletal muscle have a slightly positive Pif. (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is a multiple electrolyte solution that contains sodium lactate as a bicarbonate substrate, or buffering agent A. Sodium chloride B. Lactated Ringer C. Plasmalyte-A D. Normosol-R E. Isolyte-S

B. Lactated Ringer - Lactated Ringer solution (LR) is a multiple electrolyte solution that contains sodium lactate as a bicarbonate substrate, or buffering agent.33,41,42 This helps to maintain the electrochemical balance and neutral pH of the solution while decreasing the anionic requirement for chloride.14,41 LR is a relatively low-cost solution compared to other balanced salt solutions, and its use as a resuscitative fluid has also been shown to be more effective in preserving intravascular volume than the use of 0.9% saline. (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

In dilution technique, Low CO coincides with a _______ area under the curve because of the time required for the chilled fluid to transit through the heart. A. Smaller B. Larger

B. Larger - Dilutional techniques involve the introduction of a fixed volume of injectate into the vascular system and the consequent measure of CO and other hemodynamic variables based on the area under a time-temperature or concentration-time curve.101 The thermodilutional PAC is the classic dilutional monitoring device. A fixed volume of chilled injectate is introduced into the right atrium (RA), and blood temperature is measured with a thermistor in the pulmonary artery. CO is calculated according to the area under the time-temperature curve.101 Low CO coincides with a larger area under the curve because of the time required for the chilled fluid to transit through the heart. The PAC is the most invasive of the hemodynamic monitors used in PGDT, but it is useful in the comprehensive assessment of cardiac function.1 The PiCCO Plus hemodynamic monitor (Pulsion Medical Systems AG, Munich, Germany) applies the same thermodilutional principles using separate central venous and central arterial lines. The chilled injectate is introduced into the venous line and blood temperature is measured in the artery. This technology also applies pulse waveform analysis to provide measures of fluid responsiveness.102 The LiDCO Plus/PulseCO hemodynamic monitoring system (LiDCO Ltd, Cambridge, UK) utilizes a chemical dilution technique. A fixed volume of lithium chloride is administered intravascularly and lithium ion concentration is measured with a sensor in the artery. The software component of the system also evaluates preload responsiveness and it can be used to calculate measures of oxygenation with the input of blood gas values. (Elisha 356) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Shoemaker's fluid therapy is based on A. Mixed venous oxygen readings B. Pulmonary artery catheters C. 4-2-1 calculation D. Esophageal doppler E. Pulse contour analysis

B. Pulmonary artery catheters -The impact of perioperative goal-directed therapy (PGDT) on clinical outcomes of surgical patients has made this approach a crucial component of anesthetic practice particularly within the milieu of outcome-driven care. In the late 1980s, based on the observation that survivors of high risk surgical procedures had greater oxygen delivery (DO2), arterial oxygen content (CaO2), and cardiac index (CI) than did non-survivors, Shoemaker et al. set out to evaluate the impact of targeting supranormal hemodynamic and oxygen transport values in patients undergoing high risk surgical procedures. By placing pulmonary artery catheters (PACs) in subjects preoperatively and utilizing the hemodynamic data to help augment CI and oxygen delivery index (DO2I) throughout the perioperative period, they were able to significantly impact survival. Patients in the PA catheter protocol group had reduced mortality, reduced intensive care stays, and reduced perioperative complications, compared to those in the control.84 Shoemaker went on to publish a large body of work on the impact of hemodynamic monitoring and measures of oxygen transport on survival among surgical patients in addition to critically ill patients in septic shock.85-87 Although supranormal hemodynamic targets are no longer advocated, Shoemaker's work continues to be valued for its fundamental contribution to the advancement of goal-directed therapy - As a result of concerns regarding supranormal hemodynamic end-points, Gatinnoni and the mixed venous oxygen (SvO2) Collaborative Group studied over 10,000 patients across 56 intensive care units in 1995 to determine if targeting supranormal hemodynamic values improved survival in critically ill patients. They concluded that normal values of CI and DO2 yielded the same results as did supranormal value

HES is known to cause these in critically ill patients A. Liver failure B. Hyper coagulability C. Death D. Kidney failure

C & D - HES continues to be the subject of many conflicting studies. Randomized controlled trials have demonstrated the risk of kidney injury, dialysis requirements, coagulopathy, and even increased mortality associated with HES.11 The European Society of Intensive Care Medicine (ESICM) assembled a task force to evaluate the impacts of various colloid solutions on patient outcomes in critically ill patients. In 2012, they issued recommendations that gelatins and HES should be avoided in patients with severe sepsis, kidney impairment, neurologic injury, and in organ donors.47 Many other studies have determined that the use of HES in critically ill patients may increase the risk of renal failure and even mortality.11,41,43 The Crystalloid Versus Hydroxyethyl Starch Trials (CHEST) study assigned 7000 intensive care patients to receive either 0.9% saline or low-molecular weight HES. The study found no difference in mortality, but the patients in the HES group was found to have a significantly greater incidence of renal failure requiring renal replacement therapy (RRT).15,48 Furthermore, these adverse impacts have been shown to persist up to 90 days after HES administration.49 Based on these and other findings, the United States Food and Drug Administration (FDA) issued a black box warning for HES solutions in 2013 to notify the public of the risks of renal injury and increased mortality. - There is, however, a body of conflicting evidence. A 2016 systematic review evaluated the relative risk of HES compared to crystalloids in patients having elective noncardiac surgery. The investigators determined that there was insufficient evidence to identify a significant difference in outcomes (mortality, acute kidney injury, length of stay, and infection).51 Another study on the impact of low-molecular weight HES compared to 0.9% sa

These solutions have the most favorable acid-base profile compared to plasma; they preserve physiologic pH, renal perfusion, and overall renal function better A. Sodium chloride B. Lactated Ringer C. Plasmalyte-A D. Normosol-R E. Isolyte-S

C, D, E - Plasmalyte-A, Normosol-R, and Isolyte S are the most isotonic of the balanced salt solutions.30,36 These solutions have the most favorable acid-base profile compared to plasma; they preserve physiologic pH, renal perfusion, and overall renal function better than 0.9% saline.35,36 They also utilize sodium gluconate and sodium acetate as alkalinizing buffers rather than lactate. Furthermore, because they do not contain calcium, these solutions are compatible with blood products.11,36,43 A 2012 Cochrane review examined the perioperative administration of buffered versus nonbuffered solutions and found that whereas there was no significant difference in mortality between the cohorts, patients who received buffered solutions had less acid-base alterations and received fewer transfusions than those who received nonbuffered solutions. (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

The ultimate aim of PGDT is the following except A. Minimizing oxygen demand and optimizing CO B. Tissue oxygenation C. capillary and microvascular flow flow D. oxygen and nutrient delivery E. End-organ perfusion.

C. - The ultimate aim of PGDT is to utilize individualized hemodynamic end-points to support oxygen transport balance by minimizing oxygen demand and optimizing CO, tissue oxygenation, capillary and macrovascular flow, oxygen and nutrient delivery, and end-organ perfusion.7,98 This augments the ability of high-risk surgical patients to tolerate the metabolic and hemodynamic disturbances associated with surgery and improves clinical outcomes (Box 21.3). The ability to recognize relevant clinical end-points and manipulate real-time physiologic targets to optimize regional and global perfusion during surgery allows anesthetists to focus on definitive interventions (fluids, vasoactive support, inotropy, transfusion). (Elisha 354-355) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Isotonic crystalloids favors filtration of approximately __% to __% of administered volumes into the interstitial space A. 55 to 60 B. 65 to 70 C. 75 to 80 D. 85 to 90

C. 75 to 80 - Crystalloids are also preferred for their lack of allergenic potential, their ease of metabolism and renal clearance (compared to colloids) when infused in appropriate volumes, and their preservation of electrolyte balance despite active intraoperative plasma losses.1,13,14 However, because isotonic crystalloids are distributed evenly throughout the extracellular space, their ability to expand plasma volume is transient. Because of their low molecular weight, crystalloid solutions contribute to hemodilution of plasma proteins and loss of capillary hydrostatic pressure. This favors filtration of approximately 75% to 80% of administered volumes into the interstitial space.1,17,33 The composition of common isotonic crystalloid solutions varies (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Stretch receptors within the cardiac atrial walls stimulate the release of these A. RAAS B. ADH pathway C. ANP pathway

C. ANP pathway - Stretch receptors within the cardiac atrial walls stimulate the release of ANP from cardiac myocytes as a result of increased-preload or hypervolemic states. This stimulates the kidney to release sodium and water, thus reducing circulating blood volume and offloading the heart. ANP also produces specific vasoactive responses in the afferent and efferent renal arterioles to increase the glomerular filtration rate, and it inhibits the release of renin and ADH.28 Conversely, during periods when preload is decreased, atrial receptors inhibit the release of ANP. (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

One of the most beneficial effects of cortisol, in light of a surgical trauma is, A. Proarrhythmic B. Antiadrenergic C. Antiinflammatory D. Anticholinergic

C. Antiinflammatory - Surgical trauma and tissue injury stimulate local endothelial release of cytokines and other inflammatory mediators that contribute to hyperthermia, increased oxygen demands, and regional alterations in microcirculatory flow.57,58 Low-level cytokine release may confer benefit by promoting local hemostasis and migration of neutrophils to the site of injury; unrestricted release can contribute to vasodilation, endothelial damage, increased filtration, tissue edema, intravascular loss, hypotension, and decreased organ perfusion.57,59 Severe tissue damage associated with prolonged surgery or traumatic injury, particularly in open abdominal cases, may promote inflammatory loss of gastrointestinal endothelial integrity leading to translocation of bacteria and systemic inflammatory responses.60 One of the most beneficial effects of cortisol is the profound anti-inflammatory effect it exerts by inhibiting the production, release, and vascular aggregation of inflammatory mediators. (Elisha 352) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

The basis of the Frank-Starling mechanism is the relationship between left ventricular end diastolic volume (LVEDV) and A. Preload B. Afterload C. Contractility

C. Contractility - The basis of the Frank-Starling mechanism is the relationship between left ventricular end diastolic volume (LVEDV) and myocardial contractility (as measured by SV). An increase in left ventricular preload will, to an extent, increase myocardial contractility by stretching cardiac sarcomeres and optimizing the overlap of actin and myosin filaments to generate greater myocardial force.19 This allows the myocardium to compensate for increases in ventricular preload. The Frank-Starling mechanism is highly effective until the point at which the sarcomere cannot generate additional force; further increases in preload after this point will generate no further increases in SV. (Elisha 355) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Which is not true regarding insufflation of the abdomen A. Increase in CVP B. Stimulates release of ANP C. Decrease SVR D. Activate RAAS E. Hypocarbia

C. Decrease SVR - During insufflation of the abdomen, particularly if done rapidly or to high pressures (>12-15 mm Hg), peritoneal and mesenteric afferent receptors may stimulate a vagal response.61 Abdominal insufflation contributes to a significant increase in central venous pressure (CVP) as a result of the shunting of blood from the splanchnic circulation into the thorax. This elevation in right ventricular preload also stimulates the release of ANP.62 Increased intra-abdominal pressures may contribute to a decrease in cardiac preload by decreasing venous return. Furthermore, insufflation in hypovolemic patients may cause cardiac collapse if insufflation pressures are high enough to compress the inferior vena cava.61 Afterload is markedly increased because of elevated intrathoracic pressure and compensatory increases in SVR; this contributes to a reduction in stroke volume (SV). Although vascular flow may be markedly decreased, mean arterial pressure (MAP) is often elevated because of increased SVR. A study on the impact of pneumoperitoneum on patients who were classified as American Society of Anesthesiologists (ASA) I and II found that insufflation to pressures of 10 to 15 mm Hg significantly decreased both right and left ventricular ejection fractions.62 Patients with normal myocardial function are able to compensate for these hemodynamic alterations with tachycardia and increased left ventricular stroke work to preserve CO at the expense of increased oxygen demand. However, patients with volume overload or have decreased ventricular function may develop cardiac failure as a result of their inability to compensate.61,62 High intra-abdominal pressure decreases renal perfusion and activates RAAS. This increases vasoconstriction and fluid reabsorption associated with ADH.61 Pneumoperitoneum associated decreases in

These are synthetic colloids derived from bovine components. They have a molecular weight of 30 to 35 kDa; this is lower than most other colloids and contributes to a shorter half-life (roughly 4 hours) and limited duration of plasma expansion. have a high propensity for causing anaphylaxis, and therefore they are not available in the United States. They are also nephrotoxic and can stimulate histamine release. There have been concerns regarding their potential to transmit bovine spongiform encephalitis (BSE) A. Dextran B. Albumin C. Gelatin D. Hydroxyethyl starches

C. Gelatin - Gelatins are synthetic colloids derived from bovine components.15 They have a molecular weight of 30 to 35 kDa; this is lower than most other colloids and contributes to a shorter half-life (roughly 4 hours) and limited duration of plasma expansion.36,38,41 Gelatins, like dextrans, have a high propensity for causing anaphylaxis, and therefore they are not available in the United States.36,38,41 They are also nephrotoxic and can stimulate histamine release.11,27 There have been concerns regarding their potential to transmit bovine spongiform encephalitis (BSE). The actual risk of this transmission is unknown (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is a gel layer on the luminal surface of the vascular endothelium that plays an important protective role in transcapillary fluid exchange, microcirculatory flow, blood component rheology, plasma oncotic pressure, signal transduction, immune modulation, and vascular tone A. Substantia gelatinosa B. Glycoprotein C. Glycocalyx D. vWF

C. Glycocalyx - Starling's description of transcapillary forces has helped form the basis for our understanding of microcirculatory fluid dynamics over the past century, but recent evidence examines the importance of the capillary epithelium specifically, the endothelial glycocalyx in maintaining fluid homeostasis.16,24 The glycocalyx is a gel layer on the luminal surface of the vascular endothelium that plays an important protective role in transcapillary fluid exchange, microcirculatory flow, blood component rheology, plasma oncotic pressure, signal transduction, immune modulation, and vascular tone. (Elisha 347 -348) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is an integral component of anesthetic practice, which involves maintaining intravascular volume, augmenting cardiac output (CO), maintaining tissue perfusion, promoting oxygen delivery, correcting and maintaining electrolyte balance, enhancing microcirculatory flow, and facilitating the delivery of nutrients and clearance of metabolic waste A. Blood transfusion B. Renal replacement therapy C. Perioperative fluid management D. Volume expansion

C. Perioperative fluid management - Perioperative fluid management is an integral component of anesthetic practice, which involves maintaining intravascular volume, augmenting cardiac output (CO), maintaining tissue perfusion, promoting oxygen delivery, correcting and maintaining electrolyte balance, enhancing microcirculatory flow, and facilitating the delivery of nutrients and clearance of metabolic waste.1,2 Targeted fluid administration is a crucial tool to compensate for acute volume alterations intraoperatively, and to mitigate increased oxygen demands associated with metabolic derangements and surgical trauma. Fluid management is arguably one of the most consequential aspects of anesthetic care. The impacts of perioperative fluid handling are seen acutely in the intraoperative and immediate postoperative periods, but recently there has been a tremendous focus on the relationship between perioperative fluid administration and long-term outcomes in surgical patients. A growing body of evidence suggests that fluid balance and the complications associated with inappropriate fluid administration not only have an impact on acute postsurgical recovery, but may also influence long-term morbidity and mortality (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is the osmotic force of colloidal proteins within the vascular space A. Capillary hydrostatic pressure (Pc) B. Interstitial fluid pressure (Pif) C. Plasma oncotic pressure (mp) D. Interstitial oncotic pressure (nif)

C. Plasma oncotic pressure (mp) - Plasma oncotic pressure (πp) is the osmotic force of colloidal proteins within the vascular space. (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Activation of the hypothalamic-pituitary axis (HPA) leads to increase in A. Capillary hydrostatic pressure (Pc) B. Interstitial fluid pressure (Pif) C. Plasma oncotic pressure (mp) D. Interstitial oncotic pressure (nif)

C. Plasma oncotic pressure (mp) - Surgery and anesthesia exert complex physiologic responses that impact vascular flow and organ perfusion. Stimulation of somatic and autonomic afferent nerves in the area of surgical incision triggers the activation of the hypothalamic-pituitary axis (HPA).56As a result of this central nervous activation, the hypothalamus releases corticotropin-releasing hormone, prompting the anterior pituitary gland to secrete adrenocorticotropic hormone, which then elicits the creation and release of cortisol from the adrenal cortex.19,57,58 Cortisol stimulates protein catabolism, hepatic gluconeogenesis and glycogenolysis, and increased hepatic production and release of plasma proteins.19 These processes maintain energy substrate levels and contribute to increased πp to help preserve intravascular volume. Such evolutionary mechanisms provide cellular energy and circulating volume for the body in times of increased metabolic demand, but may be maladaptive in the setting of hyperglycemia or vascular overload. Unchecked, hyperglycemia is a major risk factor for damage or destruction of the endothelial glycocalyx; it also impairs wound healing and contributes to osmotic diuresis (Elisha 351) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This relationship is depicted as a classic left ventricular pressure-volume curve, with volume (LVEDV) appearing on the x-axis and what on the y-axis A. RVDEV B. SVR C. SV D. PVR

C. SV - This relationship is depicted as a classic left ventricular pressure-volume curve, with volume (LVEDV) appearing on the x-axis and pressure (SV) appearing on the y-axis (Fig. 21.4).11 The ascending portion of this curve represents preload dependence. Patients whose cardiac profile correspond to this curve will respond to fluid volume by increasing SV. The plateau portion of the curve represents preload independence and patients along this portion of the curve are unable to generate any additional myocardial force in response to fluid volume. Knowledge of individual patient physiology is important in assessing a patient's position along the curve. Patients with normal left ventricular function are on the physiologic curve. The long ascent of this curve suggests that the heart will continue to increase contractility in response to greater volumes of fluid. Patients with heart failure or ventricular dysfunction are on the pathophysiologic curve. The long plateau of this curve indicates that the heart can tolerate only small volumes of fluid before it is unable to increase contractility. Patients with poor ventricular compliance may proceed from a state of preload dependence to one of volume overload with the addition of very small volumes of fluid. - This underscores the importance of small fixed-volume fluid boluses as part of PGDT protocols.30 The differentiation between preload dependence and preload independence is perhaps one of the most vital components of PGDT in tailoring interventions to individual cardiovascular status and preventing complications associated with fluid overload. Failure to recognize preload independence in hypotensive patients is often the mechanism for inappropriate fluid administration. (Elisha 356) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 07

These are anatomically isolated from the fluid dynamics that impact the remaining ECV, and therefore they are considered nonfunctional A. Interstitial compartment B. Intravascular compartment C. Incracellular compartment D. Transcellular compartment

D. - Extracellular volume is further subdivided by the vascular endothelium into two additional compartments. The intravascular compartment contains plasma volume, and represents about one-fourth of ECV. The interstitial compartment is composed of extravascular fluid in the tissue spaces, and represents roughly three-fourths of ECV (Fig. 21.1).12,13,16 ECV is also composed of a small amount of transcellular fluids, including cerebrospinal fluid, synovial fluid, gastrointestinal secretions, and intraocular fluid.10,12,17 Transcellular fluids are anatomically isolated from the fluid dynamics that impact the remaining ECV, and therefore they are considered nonfunctional.17,18 Each of these volumes can be corroborated in laboratory testing with the use of radioactive water, isotope-tagged red blood cells, and selectively permeable protein-bound radioactive tracers (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Which of the following is not a contraindication for LR therapy A. Diabetics B. Traumatic brain injury C. Used as a transfusion with blood products D. Patient with metabolic acidosis

D. - LR is not recommended for large-volume administration in diabetic patients because the byproducts of hepatic metabolism of lactate are gluconeogenic.35,41 The infusion of LR may also contribute to a mild metabolic alkalosis because of the alkalinizing effect of lactate metabolism. LR is mildly hypotonic and may cause transient serum hypo-osmolality and associated cerebral edema. As a result, LR is contraindicated in patients with traumatic brain injury or other neurovascular insults.14,30 LR also contains calcium and is contraindicated for infusion with citrated transfusion products because of the risk of coagulation. (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This provides dynamic measures of preload responsiveness by quantifying the degree of change of arterial, capnography, or pulse oximetry waveforms associated with cyclic respiratory variations and the resulting pleural pressure A. Dilution techniques B. PiCCO hemodynamic monitor C. LiDCO plus monitoring system D. Pulse contour analysis

D. - Pulse contour analysis provides dynamic measures of preload responsiveness by quantifying the degree of change of arterial, capnography, or pulse oximetry waveforms associated with cyclic respiratory variations and the resulting pleural pressure. Measures of fluid responsiveness include plethysmography variability index, stroke volume variation, systolic pressure variation, and pulse pressure variation. These dynamic indices are particularly valuable in assessing real-time response to fluids and vasoactive interventions, and are often utilized as part of minimally invasive or noninvasive technologies. The utility of noninvasive monitoring platforms lies not only in their favorable risk profile, but also offers the additional advantage of continued monitoring during the immediate postoperative period. The ability to evaluate hemodynamic measures throughout the perioperative period helps ensure continuity of PGDT and promotes enhanced recovery strategies. The use of noninvasive technology to measure dynamic parameters is based on the physiology of cyclic intracardiac pressure changes during ventilation. (Elisha 356) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

The role of NS in modern anesthetic practice are the following except A. Patient at risk for cerebral edema B. Patients with anuria and ESRD who cannot excrete potassium content of other solutions C. Volume resuscitation with on a pt with hypochloremia D. Cardiothoracic patients

D. - A study comparing the perioperative impact of 0.9% saline against that of Plasmalyte found that patients in the saline group had a greater incidence of kidney failure requiring dialysis, acidosis requiring the administration of buffering agents, blood transfusions (likely secondary to the impact of acidosis on coagulation), and postoperative wound infections than did those in the Plasmalyte group.36,39 The British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients (GIFTASUP) issued a series of recommendations for perioperative fluid management, including a strong recommendation that the use of 0.9% saline be replaced by "balanced salt solutions" for fluid resuscitation except in cases of hypochloremia.40 The primary role of NS in modern anesthetic practice is in the administration of small volumes to neurosurgical patients. As a result of its mild hyperosmolality, 0.9% saline is the preferred fluid for patients at risk for cerebral edema.36 NS may also be indicated in fluid management of patients with anuria and end-stage renal disease who cannot excrete the potassium content of more balanced crystalloid solutions.14 Hypertonic saline solutions of 3% or greater are used in low-dose infusions in trauma and head-injured patients. These solutions promote volume expansion that mobilizes intracellular and interstitial fluids into the intravascular space. This may confer some protection for patients with intracranial hypertension, but there are significant risks associated with its infusion including vascular irritation, a sudden and pronounced fluid shift into the intravascular space, and the potential for dehydration of neural cells leading to osmotic demyelination syndrome. (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook f

Dynamic measures derived from pulse contour analysis are considered to be predictive of fluid responsiveness if the calculated value is greater than A. 10% B. 11% C. 12% D. 13%

D. 13% - Dynamic measures derived from pulse contour analysis are considered to be predictive of fluid responsiveness if the calculated value is greater than 13% to 15%.105 However, there is a well-documented gray zone in which values of 9% to 13% fail to accurately predict fluid responsiveness in up to 25% of patients; correlation with additional hemodynamic measures is recommended.2,30 Despite the utility of these parameters for predicting fluid responsiveness and providing real-time measures of cardiovascular response to interventions, there are some known limitations with their use (Table 21.2).6,30 The EV1000 hemodynamic monitoring system (Edwards Lifesciences, Irvine, CA, USA) allows for integration of both noninvasive and invasive (pulmonary artery, central venous, arterial) inputs to provide dynamic measures of fluid responsiveness across all inputs in addition to global hemodynamic values and measures of tissue oxygenation in the presence of invasive access (Elisha 356) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Total body water (TBW) in an average adult represents roughly __% of lean body mass A. 30 B. 40 C. 50 D. 60

D. 60 - An understanding of body fluid distribution and regulation is essential for anesthetic practice. Total body water (TBW) in an average adult represents roughly 60% of lean body mass.10 Fluid is physiologically distributed as intracellular volume (ICV), which represents roughly two-thirds of TBW, and extracellular volume (ECV), which represents one-third of TBW.11 The normal electrolyte composition of ICV differs greatly from that of ECV (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is the primary determinant of both capillary and interstitial oncotic pressures A. a-GP B. Pgp C. Hemoglobin D. Albumin

D. Albumin - Because of its smaller molecular weight and higher concentration relative to other plasma proteins, albumin is the primary determinant of both capillary and interstitial oncotic pressures.19,20 Increases in Pc and πif favor filtration of fluid into the interstitial space; increases in Pif and πp favor absorption of fluid into the intravascular space.10,12,17 The relationship between these forces is described by the Starling equation as noted - where Jv is the net fluid movement between compartments; Kf is a filtration coefficient that accounts for capillary surface area and endothelial permeability to water (capillary hydraulic conductivity); [Pc − Pif] − σ[πp − πif] is the net driving force. - Increased Kf favors filtration.20,22 σ is a reflection coefficient that ranges from 0 to 1 and accounts for the varying degree of endothelial permeability to substances such as albumin and large polar molecules. A σ of 0 indicates that the endothelium is freely permeable to the substance; a σ of 1 indicates that endothelium is completely impermeable to the substance (during capillary filtration, 100% of the substance is reflected back into the vascular lumen). (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is a gold standard for direct evaluation of cardiac function and volume status A. Pulse contour analysis B. Dilution technique C. Frank-starling mechanism D. Echocardiography

D. Echocardiography - Esophageal Doppler monitoring uses Doppler ultrasound technology to provide real-time measures of LV function and aortic compliance in addition to dynamic measures of preload responsiveness such as corrected flow time (FTc), SV, and change in peak aortic pulse wave velocity (ΔP).107 It offers a less invasive means for direct measurement of hemodynamic parameters and esophageal Doppler monitoring has become a standard of care in the United Kingdom.98 Transesophageal echocardiography is a gold standard for direct evaluation of cardiac function and volume status, although its use is limited to those who have been board certified by the National Board of Echocardiography.108 Perioperative echocardiography can provide invaluable data by providing real-time visualization of ventricular size, systolic and diastolic functional status, valvular abnormalities, volume status, wall motion abnormalities, and cardiac handling of fluid administration (Elisha 356-357) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Which of the following is not a consequence of under resuscitation of fluid administration A. PONV B. Hemoconcentraiton C. Reduced tissue perfusion D. Endothelial glycocalyx disruption

D. Endothelial glycocalyx disruption

These are synthetic macromolecules derived from starchy plants including potatoes, maize, and sorghum. Consequently they have allergenic potential in patients with reactivity to these and other components A. Dextran B. Albumin C. Gelatin D. Hydroxyethyl starches

D. Hydroxyethyl starches - Hydroxyethyl starches (HES) are synthetic macromolecules derived from starchy plants including potatoes, maize, and sorghum. Consequently they have allergenic potential in patients with reactivity to these and other components.11 HES are synthesized by substituting hydroxyl groups at the second, third, and sixth carbon atoms of the macromolecule, and are classified according to their molecular weight and substitution ratios. The C2/C6 ratio compares the degree of substitution at the second carbon to that at the sixth. A high C2/C6 ratio indicates that HES will be difficult to metabolize and will thus provide prolonged plasma volume expansion.41 The use of HES in clinical practice has been controversial. Many of the landmark initial studies on the safety and efficacy of HES were later retracted as a result of the discovery that the supporting evidence was fabricated.29,35,36 Despite this, HES have been widely used, particularly in Europe (Elisha 350) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is the osmotic force of colloidal proteins within the interstitial space A. Capillary hydrostatic pressure (Pc) B. Interstitial fluid pressure (Pif) C. Plasma oncotic pressure (mp) D. Interstitial oncotic pressure (nif)

D. Interstitial oncotic pressure (nif) - Interstitial oncotic pressure (πif) is the osmotic force of colloidal proteins within the interstitial space (Elisha 347 ) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Sodium chloride 0.9% can precipitate A. Respiratory alkalosis B. Metabolic alkalosis C. Respiratory acidosis D. Metabolic acidosis

D. Metabolic acidosis - Normal saline contains roughly equal concentrations of sodium and chloride, although the normal physiologic concentration of sodium in plasma is higher than that of chloride.34 The presence of an extraordinarily high chloride load contributes to acid-base imbalances and the well-recognized tendency for 0.9% saline to contribute to dose-dependent hyperchloremic metabolic acidosis.14,31,36 Even if compensatory mechanisms preserve a normal plasma pH, the use of 0.9% saline for volume resuscitation in acute losses is associated with marked alterations in base excess secondary to chloride load. This effect may exacerbate volume overload if negative base excess is used as an infusion trigger (Elisha 349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

This is one of the primary determinants of serum osmolality and water transport; thus the regulation of ECV is largely dependent on A. Potassium B. Calcium C. Magnesium D. Sodium

D. Sodium - In addition to the microcirculatory dynamics that govern transcapillary fluid volume distribution, there are a series of neurohormonal influences and feedback mechanisms that help to finely regulate electrolyte and fluid balance.12 Normal daily alterations in TBW are minute and intricately regulated by the renin-angiotensin-aldosterone-system (RAAS), antidiuretic hormone (ADH), and atrial natriuretic peptide (ANP) pathways.10,12,15,27 Sodium is one of the primary determinants of serum osmolality and water transport; thus the regulation of ECV is largely dependent on sodium homeostasis.12 This concept becomes tremendously important when discussing perioperative sodium loading and appropriately selecting intravenous fluids. (Elisha 348-349) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Laparoscopic surgery may cause a decrease in ____________ blood flow A. Pulmonary B. Coronary C. Cerebral D. Splachnic

D. Splachnic - Laparoscopic surgery is often preferred because its minimally invasive approach contributes to a reduction in tissue damage, blood loss, and inflammatory release (particularly of cytokines). However, laparoscopy carries risks of its own.57,58 Increased intra-abdominal pressure, secondary to pneumoperitoneum, causes direct mechanical suppression of splanchnic blood flow leading to transient splanchnic ischemia and microcirculatory changes.61 Sympathetically-mediated vasoconstriction of the splanchnic circulation also sacrifices gut mucosal tissue perfusion and predisposes the gastrointestinal epithelium to ischemia-reperfusion injury when vascular flow is restored. (Elisha 352) Elisha, Sass, John Nagelhout, Karen Plaus. Nurse Anesthesia, 6th Edition. Saunders, 072017. VitalBook file.

Which of the following is not a mechanism of renal failure A. RAAS-mediated decrease in blood flow B. Microcirculatory congestion C. Renal cortical ischemia D. Global perfusion deficits E. Restrictive fluid therapy

E. Restrictive fluid therapy - Traditional fluid management strategies have relied on infusing large volumes of fluid in the hope that renal injury could be avoided. However, there are multiple mechanisms that cause renal failure, including RAAS-mediated decreases in renal blood flow, microcirculatory congestion, renal cortical ischemia, and global perfusion deficits. A systematic review comparing restrictive perioperative fluid management with conventional techniques aimed at reversing oliguria, and the result indicated that there was no difference in the incidence of oliguria or postoperative renal failure.79 Another observational study on data mined from the Sepsis Occurrence in Acutely Ill Patients (SOAP) trial examined approximately 3,000 critical care patients and found that a positive fluid balance resulted in an increased incidence of acute renal failure.81 These and other studies challenge the classic concepts that (1) excess perioperative fluid is easily filtered by the kidneys, and (2) large fluid volumes are nephroprotective.31 The limitations of fixed volume approaches have led to an interest in the value of restrictive perioperative fluid therapy. Examination of these management techniques in comparison to traditional methods (often retroactively titled liberal) yielded various results. A partial explanation for this variability is the high degree of inconsistency in terms of defining liberal versus restrictive approaches. One study found that a liberal approach, as defined by one author, was only 10 mL different than a restrictive approach, as defined by another.82 The limitations of traditional methods have been recognized since the early 1980s, when clinicians acknowledged both the inappropriateness of current methods and the lack of measurable clinical end-points for fluid therapy. In an insightful re