Hemodynamic Practice Questions

A 45-year-old male is visiting the wellness clinic and has been newly diagnosed as a stage I hypertensive patient. His blood pressure assessment over the past 6 months has consistently been 145/92 mm Hg. The patient asks, "What is blood pressure?" What is the best response by the nurse?

"A measurement that takes into consideration the amount of blood your heart is pumping and the size of the vessel diameter the heart must pump against." The contractile force of the heart is the driving pump behind blood flow through the cardiovascular system. The ease of blood flow is a measurement of diameter of the vessel (resistance) and the volume and viscosity of blood through the cardiovascular circuit. It is within the scope of practice of a nurse to educate the patient about blood pressure. Blood pressure values may have a wide range dependent upon the pumping action of the heart, vessel diameter, and blood volume. Variations can be tolerated, but trends that remain high should be evaluated further. Blood pressure measurement is a reflection of pumping action of the heart, vessel diameter, and blood volume.

The nurse is listening to a lecture on the role of basophils. Which statement by the nurse indicates that teaching has been effective?

"Basophils respond to inflammation and allergic reactions." Basophils play an important role in acute systemic allergic reactions and inflammatory responses. "Bands" are immature neutrophils. Eosinophils are important in the defense against allergens and parasites and are thought to be involved in the detoxification of foreign proteins.

When checking a patient's pulmonary artery occlusion pressure, the nurse inflates the balloon as ordered, not inflating the balloon for more than 8 to 10 seconds. The patient asks the rationale behind the nurse's actions. Which statement should the nurse make?

"Prolonged inflation can obstruct blood flow, resulting in ischemia." Prolonged inflation of the pulmonary artery catheter balloon will compromise blood flow forward of the balloon, risking pulmonary infarction. Overinflation with a high volume of air in the balloon, rather than prolonged inflation, can lead to balloon rupture. Balloon inflation does not influence thermistor damage. Prolonged inflation will increase tension on the pulmonary artery wall.

The nurse is orienting a new RN to the ICU. The nurse begins to review orders recently entered by the cardiologist and to explain their rationale to the new RN. Medication orders include dobutamine (Dobutrex) 400 mg in 250 mL 5% dextrose in water titrated to keep cardiac index >2 L/min/m2. Which statement by the new RN indicates that teaching has been effective?

"The cardiac index is the measurement specific to the patient's size or body area." Cardiac index is cardiac output individualized to a patient's body surface area or size. Cardiac output is the amount of blood pumped out by a ventricle per minute. The amount of blood ejected with each ventricular contraction is stroke volume. The pressure created by the volume of blood in the left heart is pulmonary artery occlusive pressure.

The nurse is educating a new RN on preparing a patient for assessment of cardiac output using an esophageal monitor. Which statement by the new RN indicates that teaching was effective?

"The procedure involves a thin probe inserted into the esophagus." The procedure involves insertion of a thin silicone probe into the distal esophagus. The probe is easily placed similarly to an orogastric or nasograstric tube, so patients require little to no sedation. The procedure provides an immediate assessment of left ventricular performance. There are several contraindications to the procedure, including esophageal stricture and esophagegeal varices (see Box 8-9).

The patient is to receive one unit of platelets to treat his thrombocytopenia. His platelet count is 75,000/microliter. After his transfusion of platelets, the nurse will expect his repeat platelet count to be:

85,000/microliter. For every unit of single-donor platelets, the platelet count should increase by 5000 to 10,000/microliter. A level of 80,000 to 85,000/microliter would be expected after the transfusion.

The nurse is caring for a patient who has just been admitted to the hospital. Labs are drawn and sent to the lab. The nurse gets a call later in the day that the patient has a neutrophil count of 88% and a band level of 10%. How should the nurse interpret this?

Acute bacterial infection Neutrophils are the most numerous of the granulocytes. Band neutrophils, which are immature neutrophils, constitute only about 3% to 5%. The phrase "a shift to the left" refers to an increased number of "bands," or band neutrophils, compared with mature neutrophils on a complete blood count (CBC) report. This finding generally indicates an acute bacterial infectious process. Basophils are elevated in acute systemic allergic reactions and inflammatory responses. Lymphocytes are responsible for surveillance and destruction of virus-infected and malignant cells.

After receiving handoff report from the night shift, the nurse completes the morning assessment of a patient with severe sepsis. Vital sign assessment notes blood pressure 95/60 mm Hg, heart rate 110 beats/min, respirations 32 breaths/min, oxygen saturation (SpO2)96% on 45% oxygen via Venturi mask, temperature 101.5° F, central venous pressure (CVP/RAP) 2 mm Hg, and urine output of 10 mL for the last hour. Given this report, the nurse obtains orders for treatment that include which of the following?

Administer infusion of 500 mL 0.9% normal saline every 4 hours as needed if the CVP is <5 mm Hg. Fluid volume resuscitation is a priority in patients with severe sepsis to maintain circulating blood volume and end organ perfusion and oxygenation. A 500-mL IV bolus of 0.9% normal saline is appropriate given the patient's CVP of 2 mm Hg and hourly urine output of 10 mL/hr. There is no evidence to support the need to increase supplemental oxygen. Administration of furosemide (Lasix) in the presence of a fluid volume deficit is contraindicated. The fever may need to be treated.

What is the best understanding of mixed venous oxygen saturation by the nurse?

An overall picture of oxygen delivery and oxygen consumption Clinical determination of mixed venous oxygen saturation can be measured hemodynamically and provides a picture of the overall oxygen utilization by organs and tissues. Mixed venous oxygen saturation is the percentage of hemoglobin saturation in the central venous circulation, and it provides an assessment of the amount of oxygen used by the tissues.

The nurse is caring for a patient admitted with severe sepsis. The physician orders include the administration of large volumes of isotonic saline solution as part of early goal-directed therapy. Which of the following best represents a therapeutic end point for goal-directed fluid therapy?

Central venous pressure >8 mm Hg Early goal-directed therapy includes administration of IV fluids to keep the central venous pressure at 8 mm Hg or greater. Additional therapeutic end points include a heart rate at less than 110 beats/min and a mean arterial blood pressure at 65 mm Hg or greater. Serum lactate levels are elevated in sepsis; target levels should be <2.2 mEq/L

The nurse has been caring for a patient who has just had a surgical procedure. Labs are drawn and sent to the lab. Later in the day the nurse gets a call that the patient has a hematocrit level of 65%. How should the nurse interpret this lab result?

Dehydration If the hematocrit level increases, it is most likely due to dehydration. Fluid overload would cause an increase in plasma percentage, thereby causing a decrease in the hematocrit percentage. Hematocrit has no direct bearing on infection or immunosuppression.

The nurse admits a patient to the coronary care unit in cardiogenic shock. The nurse anticipates administering which medication in an effort to improve cardiac output by increasing the contractile force of the heart?

Dobutamine (Dobutrex) Positive inotropic agents such as dobutamine (Dobutrex) are given to increase the contractile force of the heart in cardiogenic shock. Dopamine (Intropin) is used primarily in low cardiac output states to restore vascular tone and increase blood pressure, but not in cardiogenic shock. Neo-Synephrine would be contraindicated in cardiogenic shock, as the vasoconstriction it produces would exacerbate cardiac ischemia. Nitroprusside (Nipride), used for preload and after load reduction, can improve cardiac performance in shock states by its reduction of systemic vascular resistance.

The nurse needs to obtain a cardiac output measurement from a patient who has just had a pulmonary artery catheter inserted. What are important interventions for ensuring accurate pressure and cardiac output measurements?

Ensure rapid injection of fluid through the injectate port. Zero reference the transducer system at the phlebostatic axis. To ensure accurate measurement, zero referencing of the transducer system is a priority action. Rapid injection of the appropriate solution will ensure more accurate readings. Inflating the pulmonary artery catheter balloon with 5 mL of air is likely to result in rupture of the balloon, as this volume of air is too high. Normal saline or 5% dextrose in water solutions are used for obtaining thermodilution cardiac output measurements.

The nurse is caring for a patient admitted with possible disseminated intravascular coagulation (DIC). Which laboratory test should the nurse anticipate that the health care provider will order?

Fibrin degradation product (FDP) When plasmin digests fibrinogen, fragments known as fibrin split products, or fibrin degradation products, are produced and function as potent anticoagulants. Fibrin split products are not normally present in the circulation but are seen in some hematological disorders, including DIC. The CBC reports the total RBC count and RBC indices, hematocrit, hemoglobin, WBC count and differential, platelet count, and cell morphologies; it does not detect clotting. WBCs play a key role in the defense against infectious organisms and foreign antigens, not clotting. Vitamin K deficiency is commonly associated with impaired hemostasis and bleeding, not clotting.

Which hemodynamic values should the nurse anticipate in a patient who is in the initial stages of septic shock state?

High heart rate; low right atrial pressure In septic shock, inflammatory mediators damage the endothelial cells that line blood vessels, producing profound vasodilation and increased capillary permeability. Initially this results in a high heart rate, hypotension, and low SVR, and subsequently in low right atrial pressure.

The nurse is caring for a patient with hypovolemia. Which large volume crystalloid solution should the nurse anticipate the health care provider to order?

Lactated Ringer's (LR) & Normal saline LR solution and 0.9% normal saline are isotonic solutions that are commonly infused to treat hypovolemia. Solutions of 5% dextrose in water and 0.45% normal saline are hypotonic and are not used for fluid resuscitation. Hypotonic solutions rapidly leave the intravascular space, causing interstitial and intracellular edema. A systematic review of 30 randomized controlled trials found no benefit in giving colloids (e.g., albumin) over crystalloids and recommended against the administration of colloids in most patient populations.

The nurse educator is presenting a lecture on crystalloid fluid replacement therapy in shock states. Which statement by a nurse indicates that the teaching has been effective?

Lactated Ringer's should not be infused if lactic acidosis is severe. LR solutions contain lactate, which the liver converts to bicarbonate. If liver function is normal, this will counteract lactic acidosis. However, LR should not be infused if lactic acidosis is severe. To replace every 1 mL of blood loss, 3 mL of crystalloid is administered. There is no evidence to support colloid administration being more beneficial than crystalloid administration in shock states. Hypotonic solutions such as 0.45% normal saline are not administered in shock states as these solutions rapidly leave the intravascular space, causing interstitial and intracellular edema.

The nurse is caring for a patient in shock. Which is a priority action by the nurse?

Maintain adequate tissue perfusion. Care of a patient in shock is directed toward correcting or reversing the altered circulatory component and reversing tissue hypoxia. Restoring circulating intravascular volume is the priority in improving tissue perfusion and oxygen delivery.

The nurse is caring for a patient who has blood pooling in the capillary bed and arterial blood pressure too low to support perfusion of vital organs. Which symptoms should the nurse assess for?

Multisystem organ failure and/or dysfunction Maldistribution of blood flow refers to the uneven distribution of flow to various organs and pooling of blood in the capillary beds. This impaired blood flow leads to impaired tissue perfusion and a decreased oxygen supply to the cells, all of which contribute to multiple organ failure. Damage to the type II pneumocytes leads to ARDS. Consumption of clotting factors may cause DIC. Low arterial blood pressure leads to decreased cerebral perfusion pressure.

What is the best action by the nurse to level and zero a hemodynamic monitoring system transducer?

Position the air-fluid interface of the zeroing transducer at the phlebostatic axis (fourth intercostal space, midaxillary line). To obtain accurate hemodynamic values, the transducer system must be positioned at the level of the atria and pulmonary artery, commonly termed the phlebostatic axis (fourth intercostal space, midaxillary line). The transducer must be leveled at the phlebostatic axis. The transducer must be placed at the level of the fourth intercostal space, midaxillary line.

What is the best action by the nurse to accurately record a thermodilution cardiac output (CO)?

Position the patient supine, obtain three values within 10% of each other, and calculate the average cardiac output. The average of three cardiac output measurements, all within 10% of each other, is obtained to accurately assess a cardiac output. To obtain accurate cardiac output measurements, a patient must be in the supine position with a backrest elevation of 0 to 30 degrees. Three successive measurements are taken and the average cardiac output calculated.

The nurse is caring for a patient who is being monitored with a central venous catheter. In preparing to record a right atrial pressure reading, what is most important for the nurse to keep in mind when recording an accurate value?

Record the pressure at the end of expiration. Right atrial pressures are measured at the end of expiration to ensure that pleural pressure changes do not skew the numerical value. Low pressures are generally indicative of hypovolemia, while high pressures are likely to indicate right ventricular dysfunction. Zero referencing is necessary to ensure accurate measurement and should be performed after any position change.

What is the best position for the nurse to place the patient in to obtain a right atrial pressure measurement?

Supine, either flat or with the head of the bed no more than 60 degrees Accurate assessment of a hemodynamic measure is best accomplished with the patient in a supine position with the head of the bed elevated slightly but no more than 60 degrees. The measurement can be obtained in the lateral position, but it is technically difficult because the patient must be positioned at a 30-degree lateral position for this method to be accurate. Hemodynamic measurements are not assessed in the prone position.

The nurse is caring for a patient in neurogenic shock. Which should the nurse assess for?

Vasodilation In neurogenic shock, there is an interruption of impulse transmission or blockage of sympathetic outflow, resulting in vasodilation, inhibition of baroreceptor response, and impaired thermoregulation. Interruption of sympathetic nerve innervation would result in bradycardia. Interruption of sympathetic nerve innervation would result in hypotension. Hypoventilation is not a physiological mechanism.

The nurse is caring for a patient with possible distributive shock. Which should the nurse look for on assessment?

Vasodilation and relative hypovolemia. Distributive shock presents with widespread vasodilation and decreased systemic vascular resistance that result in a relative hypovolemia. Blood loss is associated with hypovolemic shock. Decreased cardiac output is a primary cause of cardiogenic shock. Primary internal sequestration of fluids that causes internal fluid loss is associated with hypovolemic shock.

The patient has been admitted to the critical care unit with a diagnosis of sepsis. His leukocyte (WBC) and neutrophil counts are low, but his temperature is 103°F orally. The patient states that he has been feeling fine but woke up this morning feeling feverish and having chills. The nurse realizes that this patient is probably:

immunocompromised. In patients with a low neutrophil count, fatigue or malaise often coincides with the drop in counts and precedes infectious signs and symptoms. Infection must be assessed; signs or symptoms of systemic infection include a rise in temperature from its normal set point, chills, and accompanying tachycardia. Thrombocytopenia is noted by a deficiency of platelets. In sickle cell crisis, the patient often has decreased urine output, peripheral edema, and signs of uremia. Assessment of the patient with hemolytic anemia may reveal jaundice, abdominal pain, and enlargement of the spleen or liver.

The patient is admitted with a platelet count of 15,000/microliter. The nurse is aware that the patient:

is at risk for spontaneous bleeding. Thrombocytopenia is a platelet count of less than 150,000/microliter. A value of 30,000/microliter is considered critically low, and spontaneous bleeding may occur. Fatal hemorrhage is a great risk when the count is less than 10,000/microliter. The pathophysiology may be related to decreased production of platelets by the bone marrow, increased destruction of platelets, or sequestration of platelets (abnormal distribution).

The patient's hematocrit is 26%, and the patient is noted to have significant orthostatic hypotension. The nurse anticipates that the physician will order:

packed red blood cells (RBCs). Decreases in hemoglobin and hematocrit associated with symptoms of hypovolemia (orthostasis) are treated with RBC transfusions. Cryoprecipitate is usually infused if the fibrinogen level is low. Fresh frozen plasma is used to correct deficiencies in clotting factors.

Secondary hematopoietic organs that participate in hematopoietic cell production include the:

spleen, liver, thymus, lymphatic system The primary site of hematopoietic cell production is the bone marrow; however, secondary hematopoietic organs that participate in this process include the spleen, liver, thymus, lymphatic system, and lymphoid tissues.

Treatments for thrombocytopenia, other than transfusion, include:

thrombopoietin, plasmapheresis, corticosteroids, splenectomy Thrombopoietin, a platelet-stimulating cytokine, is being investigated as an alternative to platelet transfusion. Some thrombocytopenias are autoimmune induced and may respond to filtration of antibodies via plasmapheresis or immune suppression with corticosteroids. When the spleen is enlarged and tender and these other supportive therapies are unsuccessful, splenectomy can alleviate the autoimmune reaction. Aspirin is used to prevent platelet aggregation.

The nurse is teaching a class of health care workers about the risks of getting HIV. The nurse should inform the class that HIV:

transmission to health care workers is low. HIV is transmitted through exposure to infected body fluids, blood, or blood products. Common modes of transmission include rectal or vaginal intercourse with an infected person; intravenous drug use with contaminated equipment; transfusion with contaminated blood or blood products; and accidental exposure through needlesticks, breaks in the skin, gestation, or childbirth (from mother to fetus). Risk of transmission is more likely when the infected person has advanced disease, although transmission of HIV can occur at any time or stage of infection. Since the 1980s, all blood products have been screened for HIV, hepatitis virus, and human T-cell lymphotrophic virus. The risk of HIV transmission to health care workers is low.