Random SRNA*

neonatology

1. All volatile anesthetics inhibit calcium channel transmission. I have verified a journal source that states this is responsible for enhanced muscle relaxation with volatile anesthetics, but have not identified a clear source specifically stating that bradycardia and hypotension are due to calcium channel inhibition yet. It makes sense, but I don't like to presume anything without a reference to back it up. 2. Other causes of tachycardia that can present under anesthesia include stress, hypovolemia, anemia, fever, the use of inotropic or chronotropic medications, or a high catecholamine level. 3. The principal causes of tachycardia in neonates are listed above. The principal cause of hypotension in neonates is hypovolemia. Cote CJ, Lerman J, & Todres ID. A Practice of Anesthesia for Infants and Children. 4th Ed. Philadelphia: Saunders; 2009: 314, 1015.

What precautions should be taken when a patient with a pacemaker is undergoing lithotripsy?

Be certain that the lithotripsy can successfully be performed without focusing the lithotripsy beam near the pulse generator to prevent mechanical damage. Also, if the lithotripsy is set on R wave synchronization, atrial pacing should be disabled. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 5th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2006: 1547.

How can an MRI scan affect a patient's hemodynamic status?

Because of its iron content, the patient's blood flow will be altered and the blood pressure will exhibit a compensatory increase. Some patients report dizziness, headache, nausea, and strange visual sensations. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1293.

How do you calculate the maximum dose of a local anesthetic diluted with another anesthetic (lidocaine and marcaine)?

Believe it or not, there is a drug called Duocaine that is a combination of 1% lidocaine and 0.375% bupivacaine. The maximum dose of this drug is 0.18 mL/kg without epinephrine and 0.28 mL/kg with epinephrine.

Peter Stallo's 10 Tips to Writing A Research Paper/Thesis

Below are some tips I figured out after writing hundreds of papers in pursuit of my first graduate degree. By the time I was writing my thesis for UAB, I had it down to a cold science and finished the entire paper in less than two weeks. I hope it helps you, too. 1. Choose an established topic Don't choose an obscure topic. If it's the latest, cutting-edge theory or technology in anesthesia and sounds super-cool--ditch it! Anything that is cutting edge doesn't have enough research material to support a 75-100 page research paper. Think Xenon anesthesia is really neat? Don't do it. If YOU can't use it, then skip it. You need insight to write an in-depth paper and I'll just bet you haven't used Xenon in lap chole this year. You need to choose a topic that has been around for a while and has an established pattern of research. Also, established topics always have one or two cutting-edge developments that you can use to add the 'what's coming in the future' section before you write your summarizing statements. My favorite is to choose a common syndrome. Why? Because you can pick up any textbook and see the perfect outline of it: Introductory description, pathophysiology, diagnostics, anesthesia implications, and even example summary statements. 2. Don't choose a topic that is TOO established! If you do a literature search on diabetes mellitus, you will get millions of results and no idea of where to start. Pick something that is not so common that EVERYBODY has an opinion on it, a research paper about it, or a pharmaceutical commercial about it. For example, Marfan syndrome, sickle cell, and Down's syndrome are common enough to have an established base in anesthesia research, but you won't be overwhelmed with so many abstracts that you have a difficult time figuring out which ones you should use. 3. Cite every statement. A graduate-level research paper is not about your opinion...it's about the findings--and your literature review should be based on the findings of other researchers. You should not formulate an opinion at all until maybe the summary statements in which you 'wrap-up' the best of what you have already discussed into a suggested plan for integrating the information into current practice. Want to look really professional? Summarize the findings of studies with similar findings into a single sentence that explains the findings and cites them all. The more supportive citations you have, the stronger your argument that they are correct. 4. Don't use quotations unless the original author has made a statement that so accurately and succinctly describes the idea that there is no way you can summarize it or state it more clearly. You will rarely see more than a single quoted block of text in a research paper if you can find one at all. Why? If I wanted to read text from other studies, I would simply read the original study myself. As a reader of YOUR research paper, I am counting on you to do the work for me and present the information in a way that is easier for me to digest. 5. NEVER use tables, diagrams, or images from other articles. The reason is this: when you are writing your paper, you are on a tight schedule. The original author of the article or textbook that has the cool diagram or image you want to use is not...and you need his/her permission to use it. Do you really want to delay your graduation while you wait for Elsevier, Inc. to approve your use of an anatomy diagram? They could care less if you finish your paper on time and won't be in any hurry to give you the legal right to reprint their work in a graduate-level paper. 6. Keep it simple. Avoid a bunch of crazy formatting that is only going to get you red ink on your paper. I've written papers in both MLA and APA formats and the first thing I learned was to write my paper so that I could follow the basic rules without worrying about obscure citation or presentation details. If you have to look up how to cite table #3 on slide #2 of a powerpoint that was presented in Japanese at a seminar given in Canada, then you need to find an easier source to cite. If it's that much trouble, then just avoid it. Stick to standard, peer-reviewed journals with easy-to-use citations. 7. Write a complete outline and notate the journal articles you plan on using to support each statement. Once your outline is written, the rest is easy. 8. Use an alpha-based reference list for your references until you are approved for the final copy. What does this mean? In many formats, you are required to order your references according to order in which they appear. This means that if you cited references 1-20 in your first paragraph, reference #45 in paragraph 6, and references 67-70 in paragraph eight, and your instructor tells you to change the order of the paragraphs, then you have to go back and change not only the order in which the citations appear in your citations page, but also the superscript numbers throughout the entire paper. Believe me, it's a nightmare! I figured out a trick to avoid this while I was at USM--instead of using numeric superscripts during your initial drafts, I used a combination of letters and numbers like AA001, AA002, AA003, etc. When my instructor was finished rearranging all my paragraphs, all I had to do was figure out the final order and use the Find and Replace function in Microsoft Word to swap the superscript AA001 for 1, AA003 for 6, and so on. This way, by using a non-numeric citation system initially, all I had to do was swap the citation numbers using Find and Replace. Before I figured out this trick, it took me hours to correctly re-order my citations after the paper was rearranged. After I learned this trick, it took me about 10 minutes...and I had over 170 citations. 9. Pull up papers from the previous year's class. Most universities store a bound form of all research papers published by students. Browsing through these give you an immediate understanding of how the formatting is to be done. Each school uses a different standard format and several have little unique preferences as well. Southern Miss had completely different formatting expectations from the University of Alabama at Birmingham. Looking at previous papers gave me a lot of insight into how to transition from APA to MLA format. 10. Focus on getting the paper done. Don't put your ego into the paper. Doing so can tempt you into trying to perform something that is ground-breaking. The simple fact is, at the graduate-level, you won't be breaking any ground, anyway. Save that for your PhD if you want to continue in your research. We would all love to write something that changes the world...I suggest becoming a CRNA first. Then, you will have plenty of money to put back into a doctoral education designed to help you do precisely that!

What are the risks associated with leakage of the cement used in kyphoplasty and vertebroplasty?

Both kyphoplasty and vertebroplasty utilized methyl methacrylate, and so the complications that can occur from leakage of the cement are the same as for any orthopedic procedure utilizing this cement (hypotension, bradycardia, cardiac arrest). Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 61.

How do the effects of COX-1 receptor binding by NSAIDs differ from that of COX-2 receptors?

COX-1 receptor inhibition by NSAIDs is responsible for the gastric irritation, decrease in renal blood flow, and platelet inhibition associated with nonselective NSAIDs. COX-2 receptor inhibition is responsible for the decrease in pain and inflammation. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 399.

What are the two most common causes of acute pancreatitis?

Cholelithiasis and alcohol abuse account for 60-80% of all patients who develop acute pancreatitis. Acute pancreatitis is also seen frequently in patients with acquired immunodeficiency syndrome. The hypercalcemia associated with hyperparathyroidism is another frequent cause. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 291.

How do plasma levels of renin and angiotensin II change during pregnancy?

Despite the increased blood volume levels, plasma renin and angiotensin II levels are increased. In fact, by the third trimester, plasma renin activity is 12 times greater in parturients. The sensitivity of the vasculature to angiotensin II is increased but sensitivity to norepinephrine is not changed. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1103.

What is the incidence of Duchenne's muscular dystrophy and what patient demographic does it affect?

Duchenne's muscular dystrophy occurs in 3 out of every 10,000 live male births. It is an X-linked recessive disorder that presents most commonly in children between the ages of 3 and 5 years. By age 12, most patients are confined to a wheelchair. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 820.

Which steroid is most likely to produce embolism from inadvertant arterial particulate injection and why?

Methylprednisolone has the largest particle size and would be more likely to produce a significant embolus if injected arterially. Betamethasone has the smallest particles and triamcinolone is between the two. Dexamethasone contains no particles at all. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1511.

If midazolam is water-soluble, then how does it cross the blood-brain barrier and cause sedation?

Midazolam is water-soluble prior to injection. On exposure to physiologic pH, the imidazole ring of midazolam closes, making it lipid soluble. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 453-454.

What opioid receptor(s) are responsible for producing miosis?

Mu-1, Mu-2, and Kappa receptors all produce miosis. Delta is the only receptor that does not contribute to this effect. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 167. Opioids act on Mu receptors on the Edinger-Westphal nucleus, thereby allowing uninhibited parasympathetic nerve innervation of the pupil and resulting in pupillary constriction (Miosis).

What is the difference between negligence and malpractice?

Negligence is a type of tort defined as a failure to act with the prudence that a reasonable person would exercise under the same circumstances. Malpractice refers to any professional misconduct, but usually refers to negligence on the part of a professional such as a nurse anesthetist, doctor, or lawyer. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 88.

What drugs should be avoided in the patient with von Willebrand disease?

No specific anesthetic agents are contraindicated in these patients, however, it should be noted that the administration of NSAIDs such as ketorolac can adversely affect an already impaired platelet function and result in excessive or spontaneous bleeding. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 250. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 787.

Is pregnancy a contraindication to esophagogastroduodenoscopy?

No. EGD has been performed successfully in pregnant patients. Consideration should be given to the drugs administered to the parturient as they may pass to the fetus, but propofol and fentanyl have been shown to be safe. Midazolam crosses the placenta and results in fetal depression, so it is not indicated for pregnant patients. If the patient requires deep sedation and is at high risk for aspiration, general endotracheal anesthesia may be required. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1282-1283.

Is the fluid flowing out of the loop of Henle into the distal convoluted tubule hypertonic or hypotonic?

Unlike the descending limb and thin ascending limb of the loop of Henle, the thick ascending portion is permeable to solutes, but not water. This means that solutes can be reabsorbed (taken out of the loop of Henle) while water remains inside the lumen of the tubule. This results in hypotonicity of the fluid within the tubule (100-200 mOsm/L). Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 730.

How does kyphoplasty differ from vertebroplasty?

Vertebroplasty involves the injection of cement directly into the vertebral body. During a kyphoplasty, a balloon is inflated inside the vertebral body prior to injection of a more viscous cement than that used for vertebroplasty. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1524.

What mechanisms cause the vasoconstriction that occurs when a blood vessel is damaged?

When the vessel is damaged, three primary mechanisms initiate vasoconstriction to reduce the flow of blood: local myogenic spasm, autocoid factors released from the damaged tissues and platelets, and reflex vasospasm mediated by pain fibers. The most powerful of these factors is myogenic spasm. In smaller vessels, thromboxane A2 released from platelets results in vasoconstriction as well. Guyton AC, & Hall, JE. Textbook of Medical Physiology. 12th ed. Philadelphia: Saunders; 2011: 451.

How is the hematocrit affected by severe burns? How does this affect the cardiac output?

With a significant thermal insult, there is a massive shift of fluid to the interstitium which concentrates the blood volume, resulting in an increase in the hematocrit and the blood viscosity. The cardiac output declines, up to 50% due to the decrease in intravascular volume and increase in viscosity. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 870-872. [see fig 41-2]

How does obesity hypoventilation syndrome differ from the typical respiratory changes associated with morbid obesity?

With simple morbid obesity, the PaCO2, pH, and pulmonary compliance are still in the range of normal values. OHS is present when the morbidly obese patient exhibits inappropriate somnolence, sleep apnea, hypoxemia, hypercapnia, and decreased alveolar ventilation. Polycythemia, enlarged heart, and cyanosis may also be present. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1029.

Can you explain to me the significance of dialing down the mA on the PNS from 1 to 0.4 during regional blocks? Why do we do that?

Yep! If the milliamp setting is at 1, the spread of the current is strong enough to stimulate the nerve (and cause contraction of the innervated muscle) from a considerable distance away. By dialing the setting to a lower current, it ensures that you are getting close enough to the nerve to infiltrate the tissue around it with local anesthetic accurately and get a good block. You shouldn't dial the setting down any lower, however, because you may be so close to the nerve by the time you get a muscle contraction that you could risk intraneural injection.

Have you ever heard that Benadryl can be used as a local anesthetic?

Yep, in fact you can find a bunch of older articles on it at the national library of medicine website about how to use, its efficacy, etc. Go to http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2516640/ and take a look.

after exsanguinating with Eschmark bandage you should inflat the proximal tourniquet according to Morgan & Mikhail. But why would you not inflate the distal first, proximal second, and then deflate the distal third to help further exsanguinate? In practice I would think that this would be the appropriate method, however if test questions say to inflate the proximal first then that is how I would answer.

you definitely inflate the distal cuff over the anesthetized part of the arm when the tourniquet time gets too high. About 45 minutes will make the toughest patients try to get up and put their shoes on so they get the heck out of there. Switching the tourniquet only seems to buy you about another 15 minutes at the most, though. Bier blocks can be pretty tough at first. My first 5-6 Bier blocks still involved propofol, sevoflurane, and an LMA anyway.

What is the difference between placenta accreta, placenta increta, and placenta percreta?

Placenta accreta is a condition where the placenta adheres to the surface of the myometrium, placenta increta refers to placental implantation within the myometrium, and placenta percreta refers to the condition where the placenta completely penetrates the myometrium. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 3rd ed. New York, NY: McGraw-Hill; 2002: 835.

Why does polyuria occur in patient's with supraventricular tachycardia?

Polyuria may result from SVT (or any other atrial tachycardia resulting in AV dys-synchrony) due to an increased secretion of atrial natriuretic peptide due to the increased atrial pressures that result from atrial contraction against a closed AV valve. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 65.

What are the renal signs and symptoms of hyperparathyroidism?

Polyuria, polydipsia, decreased glomerular filtration rate, hypophosphatemia, hyperchloremic acidosis and renal stones. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 399. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 1603.

What are the concerns regarding PPV in patients with long-standing tuberculosis?

Positive-pressure ventilation can result in massive hemoptysis in patients with long-standing pulmonary TB. Many practitioners prefer to employ spontaneous ventilation if at all possible to reduce the risk of hemoptysis. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 494.

Are premature infants at an increased risk for developing hyperglycemia or hypoglycemia?

Premature infants are at risk for developing both hyperglycemia and hypoglycemia. Decreased stores of adipose tissue and lower glycogen stores predispose them to hypoglycemia during fasting. They also exhibit a decreased insulin production, so they are more susceptible to hyperglycemia from dextrose infusions. Cote CJ, Lerman J, & Todres ID. A Practice of Anesthesia for Infants and Children. 4th Ed. Philadelphia: Saunders; 2009: 739.

How can I remember which drugs decrease CSF production?

Remember the mnemonic: "CSF Is Always decreased" so that you associated the drugs beginning with "CSFIA" with decreased CSF. They stand for: Corticosteroids Spironolactone Furosemide Isoflurane Acetazolamide It's that easy!

How does hyperventilation affect the phosphate level?

Respiratory alkalosis from hyperventilation decreases phosphate levels. Respiratory alkalosis is also presumed to be the cause of hypophosphatemia associated with gram-negative sepsis and salicylate poisoning. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 319.

What is the difference between a Type I and a Type II error in a research design?

Ryan asked this question, which appeared on one of his class exams. The answer to this one actually appears in the Research and Statistics Terminology article that appears in the PACES program and is also available for free in the Article Archives at www.prodigyanesthesia.com Thanks Ryan! That one is like free advertising! BTW, I am still working on your other question, which is not in PACES (yet), but I should have the answer posted tomorrow night. A Type I error is when researchers, on the basis of a statistical test, erroneously conclude that there IS evidence of an association between two variables when, in fact, there is NOT A Type II error is the exact opposite-- it is when researchers, on the basis of a statistical test, erroneously conclude that there is NOT evidence of association between two variables when, in fact there IS Polgar S & Thomas SA. Introduction to Research in the Health Sciences. 5th ed. Edinburgh: Elsevier Health Sciences; 2008.

pocket guides for OR

http://www.amazon.com/Anesthesiology-Pocketcard-Set-Ruchir-Gupta/dp/1591030501/ref=pd_sim_b_1 www.simplyanesthesia.com

What is the anatomic dead space of an infant?

As I'm sure you know, the anatomic dead space in an adult male is about 2 mL/kg or about 150 mL in the ideal-weight male. In the full-term infant, however, the correct value is 3 mL/Kg. So, an average 6-month old who weighs 8 kilograms would have an anatomic deadspace of 24 mL. For information on the original research that determined the calculation we use today, see Numa AH & Newth CJ. Anatomic dead space in infants and children. Journal of Applied Physiology. May 1996 vol. 80 no. 5 1485-1489.

What is the most common cause of shock in pediatric patients?

"Blood loss due to trauma is the most common cause of shock in children." The compensatory mechanisms of tachycardia and vasoconstriction are extremely efficient in pediatric patients. A child may lose 25% of his blood volume without exhibiting changes in the heart rate or blood pressure in the supine position. Cote CJ, Lerman J, & Todres ID. A Practice of Anesthesia for Infants and Children. 4th Ed. Philadelphia: Saunders; 2009: 778.

How can I remember which local anesthetics are amides and which are esters?

I used this mnemonic when I was in school: The word 'amide' has a letter I in it and the amides have TWO I's in their name: lidocaine, prilocaine, bupivacaine, mepivacaine, ropivacaine, etidocaine, and dibucaine. Ester anesthetics contain only ONE I in their name: cocaine, chloroprocaine, tetracaine, and benzocaine I remember it as "one-eyed Ester". Just remember, the exception to this rule is piperocaine. It has two I's, but is actually an ester...

How Do I Calculate A-a Gradients?

I wrote it in a step-by-step method with lots of examples of 25 practice problems. The workbook is 14 pages long, so I can't explain it all here, but I posted it in the article archives at www.prodigyanesthesia.com/archives.htm This workbook is free, so download it, print it out, email it to your class, and by page 14, you'll be a master of A-a gradients!

Can a healthcare provider be shocked by a patient's AICD?

If in physical contact with a patient who has an AICD that is discharging, a healthcare provider can receive a mild shock that is not capable of causing fibrillation in the caregiver, but can be distressing while attempting to administer care to the patient. If a patient is experiencing 'electrical storm' from the defibrillator (numerous shocks are being discharged in a short period of time) it is recommended to place the patient on an ECG monitor and watch for periods of VT or VF that last about 4 seconds. This will give the caregiver several seconds warning before a shock is discharged to cease physical contact with the patient. Davis, C. (2007). Electrical Storm and Implanted Defibrillators. Southern Medical Journal, 100, 547-548

What governmental agency has authority over the safety standards for medical devices? What law gives them this power?

In May 1976, the Medical Device Amendments gave the FDA specific authority for the regulation of medical devices. Within the FDA, device regulation falls under the auspices of the Center for Devices and Radiological Health. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 489.

What is the most common cause of airway obstruction in pediatric patients?

In awake patients, the most common causes of airway obstruction are croup and foreign body inhalation. In obtunded patients (such as immediately postop in the PACU), the most common cause of airway obstruction is the tongue. The tongue is relatively large in proportion to the rest of the pediatric airway, especially in the neonate, and obstructs the airway easily. Cote CJ, Lerman J, & Todres ID. A Practice of Anesthesia for Infants and Children. 4th Ed. Philadelphia: Saunders; 2009: 237.

How do the hemodynamic goals for mitral regurgitation differ from those of mitral stenosis? How are they similar?

In mitral regurgitation, your goal is to maintain an increased heart rate and decreased afterload while the goal in mitral stenosis is maintain at normal or decreased heart rate and normal afterload. In both disorders, you should maintain normal sinus rhythm, avoid increases in pulmonary vascular resistance, and maintain preload at normal to increased levels. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 496.

What is the most prudent action to take when faced with severe, opioid-induced muscle rigidity at induction?

Large doses of narcotics, particularly fentanyl, sufentanil, and alfentanil, can result in chest wall rigidity that can make ventilation difficult or impossible. Administration of a fast-acting muscle relaxant such as succinylcholine can relieve the rigidity and make ventilation possible. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 477-478.

How does congestive heart failure prolong the half-life of lidocaine?

Like other amide local anesthetics, lidocaine is metabolized by carboxylesterases and (most importantly) the cytochrome P-450 system. Thus, anything that decreases hepatic enzyme activity or decreases hepatic blood flow will result in a prolonged half-life of the drug. In severe hepatic failure, the plasma half-life of lidocaine is prolonged from 1.8 hours to 4.9 hours. This is due to both a decrease in enzyme activity AND hepatic blood flow. The plasma half-life is increased in patients with congestive heart failure as well, because of the significant decrease in hepatic blood flow. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 152.

What is the risk of death due to anesthesia?

A 2002 study identified the risk of death solely due to anesthesia-related causes to be about 1 in 200,000. So what does that mean in real terms? Let's compare the risk of anesthesia to other causes of death: 1. You are more likely to die in a flood (1 in 175,803) than die from anesthesia. 2. You are more likely to die in an earthquake (1 in 148,756) 3. You are more likely to die from a dog attack (1 in 120,864) 4. You are more than twice as likely to die from a legal execution for a capital crime (1 in 96,691) 5. You are more than twenty times like to from electrocution (1 in 9,943) 6. You are 660 times more likely to die in a car wreck (1 in 303) It's important to remember that no one can guarantee absolute safety for any individual undergoing anesthesia (statistics only apply to populations--they don't apply to a single individual), but it's also important to be able to convey the comparative risk of anesthesia to the general population. Oh yeah, and if this makes you feel a little overconfident, don't forget to tell them that the chance you will knock their teeth out is 1 in 2047. Lagasse RS (2002). "Anesthesia safety: model or myth? A review of the published literature and analysis of current original data". Anesthesiology 97 (6): 1609-17. National Safety Data Council, Injury Facts 2011 J Clin Anesth. 2007 Aug;19(5):339-45.

What are the three different methods of defining hypoxemia?

A 5% drop in O2 saturation, an O2 saturation < 90%, and a PaO2 < 60 mmHg are all definitions of hypoxemia. Gaba DM, Fish KJ, Howard SK. Crisis Management in Anesthesiology. Philadelphia, PA: Churchill Livingstone; 1994: 79.

What's the composition of EMLA Cream?

A few students have asked why I state in the PACES software that EMLA cream is 2.5% lidocaine and 2.5% prilocaine when Morgan & Mikhail clearly state that it is 5% of each anesthetic. (See Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 268.) The fact is, the Morgan & Mikhail textbook is wrong in this matter. And it's an important distinction because EMLA cream is on your boards. If you would like to verify this for yourself or want more information, you can download the Astra-Zeneca package insert at http://www1.astrazeneca-us.com/pi/EMLA.pdf Also, I have posted an article about EMLA cream in the Article Archives on the website at www.prodigyanesthesia.com/archives.htm that explains everything you need to know about EMLA cream.

What is a hemipelvectomy and why would it be performed? What are the anesthetic implications for this procedure

A hemipelvectomy is an amputation of the entire leg and ipsilateral pelvis. Reasons for performing this rarest of amputations include trauma such as car accident or cancers such as osteosarcoma, chondrosarcoma, or Ewing's sarcoma. The primary anesthetic concerns in these patients involve the extensive trauma, blood loss, and postoperative pain associated with the procedure. A study in Australia reported that the mean crystalloid requirement was 8500 mL with an average of 7 units of blood transfused. A combination of epidural/general anesthesia is often implemented. Fluid and forced air warmers are a necessity and the patient can be expected to recover in the intensive care unit. Molnar R, Emery G, Choong PF. Anaesthesia for hemipelvectomy--a series of 49 cases. Anaesth Intensive Care. 2007 Aug;35(4):536-43.

What is the difference between the terms 'motion to dismiss' and 'motion to suppress'?

A motion to dismiss is a request that the court throw out the lawsuit on the grounds that it has no legal merit. A motion to suppress is typically made on behalf of an alleged criminal to preclude certain evidence from being shown in trial. Berch BA, Berch RW, & Spritzer RS. Introduction to Legal Method and Process: Cases and Materials. 4th ed. St. Paul, MN: Thomson-West; 2002: 617.

What age-group is most affected by epiglottitis?

Ages 2-7 are the most commonly affected, although the relative incidence has increased in the adult population as routine Haemophilus vaccination has decreased the incidence in the pediatric population. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 615.

What is the most sensitive indicator of cardiac ischemia during thoracic surgery when the aorta is cross-clamped?

Although TEE and 12-lead ECG have little advantage over preoperative clinical data and two-lead ECG monitoring in non-cardiac surgery, the advantage of TEE during cardiac or thoracic surgery is clear. In one study, TEE detected wall-motion abnormalities in 11 out of 12 patients, while the pulmonary artery occlusive pressure remained unchanged in 10 of them. Additionally, during the period of ischemia, no significant changes occurred in the heart rate or systolic pressure. Yao FF. Anesthesiology: Problem-Oriented Patient Management. 6th ed. Philadelphia: Lippincott, Williams, and Wilkins; 2008: 149.

A patient on vasopressors undergoing tracheal resection requires an a-line. Where should you place it? Why?

An arterial line should be placed in the left radial artery to provide continuous monitoring of blood pressure during periods of compression of the innominate artery. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1063.

Why does carcinoid syndrome tend to cause right-sided heart problems only?

Elevated serotonin levels can result in right-sided heart failure. The lungs metabolize serotonin, thus sparing the left side of the heart. The presence of a right-to-left shunt, however, would expose the left side of the heart to the serotonin and cause left-sided heart symptoms. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 815. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 290.

How are somatosensory evoked potentials affected by the administration of opioids? Ketamine? Etomidate? Clonidine?

Etomidate and ketamine both increase SSEP amplitude. Opioids and clonidine can be used with little to no effect on SSEP monitoring. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 610. Opioid analgesics normally produce very mild effects on evoked potentials. The effects are mainly minimal changes in spinal or subcortical responses where there is some amplitude depression and increased latency in cortical response. Definitely less effects than inhalational agents ie enflurane, halothane and more potently, isoflurane. The effects of inhalational agents is different because of the dose related latency and reduction of cortical SSEP which can result in unstable responses over a period of time. Answer based on research by anesthesiologist at ASNM (American Society of Neurophysiological Monitoring)

What is the mechanism by which MAC is reduced by neuraxial blockade?

Even though neuraxial blockade doesn't affect cranial nerve function like other factors that decrease MAC (hypothermia, hypnotics, opioids, antidepressants, anti-seizure medications, etc) it decreases MAC by inhibiting the ascending spinal cord signals that stimulate cortical arousal in the brainstem. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 752.

What are the advantages and disadvantages of using fenoldopam to induce controlled hypotension?

Fenoldopam preserves renal perfusion but can result in reflex tachycardia, rebound hypertension, and can increase pulmonary shunting. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 930

3 books give 3 different values for serum T4! Which one is correct?!?

Figuring out the normal range for the serum T4 level can be a little difficult, especially since three books cite three radically different values: Ferri's Best Test 2nd Ed cites it as 0.8-2.8 NANOgrams/dL, Stoelting's Anesthesia & Co-Existing Disease states it is 5-12 MICROgrams/dl, and Morgan & Mikhail's Clinical Anesthesiology states that anything greater than 1 MILLIgram is ok. So, which is it? Nanograms, Micrograms, or Milligrams? Let's start by first stating that Morgan & Mikhail has a typo. It states milligrams and should be micrograms. A corrected statement from page 809 of the 4th edition should state that 'any elective procedure should be canceled in a patient with a serum total T4 less than 1 mcg/dL. Second, Ferri's Best Test and Stoelting's Anesthesia & Co-Existing Disease are discussing two different lab tests. The value that Stoelting provides on pg 381 of the 5th edition states that the normal range for serum T4 is 5-12 mcg/dL. This is correct, because it is discussing TOTAL T4, not free T4. Ferri's Best Test states that the normal free T4 is 0.8-2.8 nanograms/dL, which is also correct. Only a small amount of the total T4 is free in the bloodstream. So, in summary: Normal Total T4 is 5-12 mcg/dL Normal Free T4 is 0.8-2.8 mcg/dL and you should cancel elective surgery for a total T4 less than 1 mcg/dL. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 809. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 380. Ferri FF. Ferri's Best Test. 2nd ed. Philadelphia, PA: Mosby-Elsevier; 2010: 149.

What three muscles does the hypoglossal (XII) innervate?

Genioglossus, hyoglossus, and styloglossus Moses KP, Banks JC, Nava PB, Petersen D. Atlas of Clinical Gross Anatomy. Philadelphia, PA: Mosby-Elsevier; 2005: 6-144

How are glucagon levels affected by cirrhosis and what are the anesthetic implications of this alteration?

Glucagon levels are elevated in patients with cirrhosis. As a result, they have a reduced ability to respond effectively to the administration of catecholamines and pressor agents. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1261.

Anesthesia Links

HAART Guidelines posted by Shiro Njoroge http://www.aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf AANA website http://www.aana.com/ (posted by Cheryl Dreyer) Acid Base physiology http://www.anaesthesiamcq.com/AcidBaseBook/ABindex.php (posted by Cheryl Dreyer) Airway Carnival http://www.airwaycarnival.com/ (posted by Cheryl Dreyer) Anesthesia Cases http://www.anaesthesiacases.com/ (posted by Cheryl Dreyer) Anesthesia Central http://anesth.unboundmedicine.com/anesthesia/ub/view/The-Manual-of-Anesthesia- Practice/102647/all/anesthesia_machine_check (posted by Cheryl Dreyer) Anesthesia Gas Machine http://www.udmercy.edu/crna/agm/ (posted by Cheryl Dreyer) Anesthesia Pharmacology http://www.anesthesia2000.com/learning2.htm (posted by Cheryl Dreyer) Anesthesia UK http://www.frca.co.uk/ (posted by Cheryl Dreyer) Anesthesia Web http://www.anesthesiaweb.com/ (posted by Cheryl Dreyer) Capnography http://www.capnography.com/ (posted by Thomas Romero) Cardiac Surgery Made Simple http://www.cardiacengineering.com/cardiaca.htm (posted by Cheryl Dreyer) Chem Tutor Gases http://www.chemtutor.com/gases.htm#dalton (posted by Cheryl Dreyer) Critical Care Tutorials http://www.ccmtutorials.com/intro/overview/page_02.htm (posted by Cheryl Dreyer) Dr. Najeeb Online Physiology Lectures http://www.youtube.com/DoctorNajeeb (posted by Cheryl Dreyer) EKG Learning Center http://library.med.utah.edu/kw/ecg/ (posted by Cheryl Dreyer) Family Practice Notebook http://www.fpnotebook.com/index.htm (posted by Cheryl Dreyer) FANA http://www.fana.org/default.asp (posted by Cheryl Dreyer) Fluid Physiology http://www.anaesthesiamcq.com/FluidBook/index.php (posted by Cheryl Dreyer) HAART Guidelines http://www.aidsinfo.nih.gov/ContentFiles/AdultandAdolescentGL.pdf (posted by Shiro Njoroge Interactive Atlas of the Larynx https://www1.columbia.edu/sec/itc/hs/medical/anatomy_resources/anatomy/larynx/ (posted by Cheryl Dreyer) International Federation of Nurse Anesthesia http://ifna-int.org/ifna/news.php (posted by Cheryl Dreyer) Khan Academy Tutorials http://www.khanacademy.org/ (posted by Cheryl Dreyer) Larynx Intrinsic Muscle Animation http://www.getbodysmart.com/ap2/respiratorysystem/larynx/intrinsicmuscles/tutorial.html (posted by Cheryl Dreyer) LMA Insertion Video http://www.youtube.com/watch?v=sBps7rxYVg8 (posted by Cheryl Dreyer) Malignant Hyperthermia Association http://www.mhaus.org/ (posted by Cheryl Dreyer) Math Review http://www.udmercy.edu/crna/agm/mathweb.htm (posted by Cheryl Dreyer) Neuroanatomy http://library.med.utah.edu/kw/animations/hyperbrain/pathways/index.html (posted by Cheryl Dreyer) New York School of Regional Anesthesia http://www.nysora.com/ (posted by Cheryl Dreyer) O2 Demand http://o2demand.com/ (posted by Cheryl Dreyer) Online Airway Quizzes http://www.wiley.com/college/apcentral/anatomydrill/t23/at2307_1.htm (posted by Cheryl Dreyer) Open Anesthesia.Org http://www.openanesthesia.org/index.php?title=Main_Page (posted by Cheryl Dreyer) Pediatric Dose Calculator http://www.pana.org/pedform.htm (posted by Cheryl Dreyer) Radiology Anatomy http://www.med.wayne.edu/diagradiology/Anatomy_Modules/Page1.html (posted by Cheryl Dreyer) Thoracic Anesthesia http://www.thoracic-anesthesia.com/ (posted by Cheryl Dreyer) USMLE Online Lectures http://www.youtube.com/user/USMLEOnline#p/a (posted by Cheryl Dreyer) Virtual Anesthesia Machine http://vam.anest.ufl.edu/ (posted by Cheryl Dreyer) Virtual Anesthesia Textbook http://www.virtual-anesthesia-textbook.com/index.shtml (posted by Cheryl Dreyer) http://ccnmtl.columbia.edu/draft/heart/ex1.html Scroll down to the bottom of the page. In the left hand corner is a small button that states "Display Heart Flow Program." Interactive pop-up screens.

How does the severity, course of illness, and laboratory findings in hemophilia B compare to that of hemophilia A?

Hemophilia A is an X-linked recessive clotting disorder that results in a deficiency of factor VIII. Hemophilia B is an X-linked recessive coagulation disorder caused by a deficiency of factor IX. Except for the specific clotting factor involved, the course of illness with hemophilia B is almost identical to that of hemophilia A. Also like hemophilia A, severe hemophilia B occurs when less than 1% of the normal amount of factor is present and becomes considerably milder when patients have between 5% and 40% of the normal amount of factor. Like hemophilia A, patients with hemophilia B exhibit a prolonged PTT and a normal PT. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 420.

With relation to HIV, what does the acronym HAART stand for?

Highly active antiretroviral therapy, which represents the current drug regimen used to prevent the advancement of HIV infection into AIDS. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 489. Midazolam (midazolam is contraindicated for patients on Protease Inhibitors(PIs) and Non-nucleoside reverse transcriptase inhibitors (NNRTIs). Also, H2 antagonists should be given at least 2 hours after last dose of protease inhibitors. PIs are CYP450 inhibitors, while NNRTIs are CYP450 innducers. In OB, you must avoid methergine in patients on protease Inhibitors (severe vasoconstriction may occur). The 2010 CDC guidelines state that unless there is no alternative therapy available. I doubt this info would be tested on boards, but I think its helpful if caring for a patient on HAART.

What is congenital aganglionosis?

Hirschsprung's disease, also known as congenital aganglionosis, is characterized by a tonic contracture of the bowel starting at the dentate line of the anus and extending proximally for a variable distance. This contracture produces a functional bowel obstruction. As a result, the more proximal bowel dilates dramatically. Symptoms range from mild constipation to toxic enterocolitis requiring an emergency colostomy. Jaffe RA, Samuels SI. Anesthesiologist's Manual of Surgical Procedures. 4th ed. Philadelphia, PA: Lippincott Williams and Wilkins, 2009: 1300-1304.

A patient exhibits hyponatremia with a high serum osmolarity. What diuretic would most likely cause this phenomenon?

Hyponatremia with a normal or high serum osmolarity result from the presence of non-sodium solutes such as mannitol. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 305.

Most body tissues can survive for a considerable amount of time without oxygen. Why can't the brain do this?

Non-neural tissues can obtain energy from anaerobic mechanisms, enabling them to acquire energy from glucose and glycogen without the use of oxygen. The brain has a metabolic rate that is about 7.5 times that of non-neural tissues and cannot utilize anaerobic mechanisms effectively. As a result, the brain depends upon second-by-second delivery of oxygen for it to function correctly. Whereas peripheral tissues can tolerate a loss of arterial flow for a considerable period of time before severe damage occurs, the interruption of blood flow to the brain for even 5 seconds can produce unconsciousness. Guyton AC, & Hall, JE. Textbook of Medical Physiology. 12th ed. Philadelphia: Saunders; 2011: 749.

What is your next intervention if you have an anaphylactic shock that is refractory to epinephrine?

Norepinephrine, metaraminol and glucagon for β-blocked patients are recommended in the treatment of anaphylactic shock refractory to epinephrine. Also, arginine vasopressin (AVP) has been suggested as an alternative in the event epinephrine is not sufficient to restore homeostasis in anaphylactic shock. Harper NJ, Dixon T, Dugué P, Edgar DM, Fay A, Gooi HC, Herriot R, Hopkins P, Hunter JM, Mirakian R, Pumphrey RS, Seneviratne SL, Walls AF, Williams P, Wildsmith JA, Wood P, Nasser AS, Powell RK, Mirakhur R, Soar J; Working Party of the Association of Anaesthetists of Great Britain and Ireland. Suspected anaphylactic reactions associated with anaesthesia. Anaesthesia 2009;64:199- 211. Kroigaard M, Garvey LH, Gillberg L, Johansson SG, Mosbech H, Florvaag E, Harboe T, Eriksson LI, Dahlgren G, Seeman-Lodding H, Takala R, Wattwil M, Hirlekar G, Dahlén B, Guttormsen AB. Scandinavian Clinical Practice Guidelines on the diagnosis, management and follow-up of anaphylaxis during anaesthesia. Acta Anaesthesiol Scand 2007;51:655-70. Joint Task Force on Practice Parameters; American Academy of Allergy, Asthma and Immunology; American College of Allergy, Asthma and Immunology; Joint Council of Allergy, Asthma and Immunology. The diagnosis and management of anaphylaxis: an updated practice parameter. J Allergy Clin Immunol 2005;115:S483-523.

What is the difference between obesity hypoventilation syndrome and sleep apnea?

Obesity hyperventilation syndrome is equally common among males and females, exhibits an awake PaCO2 that is at least 45 mmHg, exhibits pulmonary hypertension that is more common and more severe than that seen with obstructive sleep apnea, and doesn't exhibit nocturnal airway obstruction unless concomitant OSA is present. Obstructive sleep apnea exhibits a normal awake PaCO2 that increases during sleep-induced obstruction, can exhibit pulmonary hypertension but is less common than OHS, and occurs more frequently in males than females. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1233.

name the cranial nerve with which the Edinger-Westphal is associated?

Oculomotor. CN III

Which induction agent has a greater risk of thromboplebitis? Thiopental or Propofol

Okay Michelle, I had to dig a little deeper on this one. I couldn't find anything in the textbooks that compared the two, but I did find a recent study in an Indian Journal that made this comparison, so here you go: A 2010 study reported in the Indian Journal of Anesthesia evaluated the incidence of thrombophlebitis highest in patients undergoing electroconvulsive therapy receiving thiopental, propofol, and midazolam. Their findings indicated that the incidence of thrombophlebitis was highest in the group receiving thiopental (3.3%). Indian J Anaesth. 2010 Jul-Aug; 54(4): 296-301. For those who wish to learn more, the entire study is available online at: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2943697/

What is the pathophysiologic difference between open-angle and closed-angle glaucoma?

Open-angle glaucoma is characterized by a patent anterior chamber angle and the drainage of aqueous humor is impaired by sclerosis of the trabecular tissue. In closed-angle glaucoma, the drainage of aqueous humor is impaired by a shallow anterior chamber and a narrow iridocorneal angle that results in the trabecular network being obstructed by the iris. Fleisher LA. Anesthesia and Uncommon Diseases. 5th ed. Philadelphia, PA: Saunders and Elsevier; 2006: 5.

What are the symptoms of complex regional pain syndrome?

Pain that occurs spontaneously without an apparent stimulus, hyperalgesia, allodynia, and sudomotor and vasomotor dysfunction. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1517.

What are the typical diagnostic findings in patients with hypertrophic cardiomyopathy?

Patients often exhibit a harsh systolic murmur, signs of LVH on the ECG and deep, broad Q waves. Echocardiography will demonstrate the abnormal peak pressure gradient and thallium-201 scans may detect myocardial perfusion defects even in healthy patients. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 475.

In what proportions do pheochromocytomas release norepinephrine and epinephrine?

Pheochromocytomas typically release 85% norepinephrine and 15% epinephrine. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 389.

Specificity vs Sensitivity

Sensitivity assesses a test's ability to identify people who are Positive for the disease. Specificity assesses a test's ability to identify people who are Negative for the disease. The easiest mnemonic tells you what they DON'T do: Sensitivity has an N in it and so it doesn't check for Negatives. Specificity doesn't have a P in it and so it doesn't check for Positives. I actually found a very comprehensive explanation on the topic at wikipedia that explains in much more detail than I can here. It's at http://en.wikipedia.org/wiki/Sensitivity_and_specificity Normally, I dodge wikipedia for anything, but this article does a good job of helping you to understand if you're stuck. it may be strange or unhelpful...but here's how I remember it. First: I put the two "S" words in alphabetical order. Sensitivity, then Specificity. Second: I just think "plus or minus". You always hear plus then minus...not the other way around. Now you've got your order. Just match them up. Sensitivity; Specificity Positive; Negative So in each step Sensitivity and plus come first...so they go together (and vice versa). Sensitivity= true positive (plus); Specificity= true negative (minus) Hope this helps someone!

Maximal allowable blood loss

The MABL formula is (EBV X (Initial Hct - Lowest Hct))/Initial Hct. it is the same formula mentioned by Miller's and Barash.

What is the difference between the Hawthorne and Rosenthal effects?

The Rosenthal effect occurs when the outcome of a study is skewed when the subject responds based on an awareness of the experimenters expectations. The Hawthorne effect occurs when subjects performance is altered by an awareness that they are being observed. For example, during a preoperative interview, the student nurse anesthetist asks the patient, "You don't have anything disgusting like TB or Hepatitis B do you?" The patient answers, "No" even though he does have Hepatitis B, because he is aware by the language used that the student expects the answer "No" and would probably react disapprovingly if he told the truth. This is an example of the Rosenthal effect. When a group of nurse anesthetists know they are being visited by JCAHO on a given day, they're behavior and adherence to JCAHO rules is likely to be much more strict that day than on any other, simply because they wish to be recognized as ones who follow the rules well and don't violate JCAHO recommendations. This is an example of the Hawthorne effect. Polgar S & Thomas SA. Introduction to Research in the Health Sciences. 5th ed. Edinburgh: Elsevier Health Sciences; 2008: 59, 293-299.

Why would someone choose a Crawford needle over a Tuohy needle for placement of an epidural catheter?

The Tuohy needle allows for easier threading of the epidural catheter when approaching the epidural space perpendicularly. The bend in the needle tip assists in directing the catheter tip upward. When using a more acute angle, such as a paramedian approach, the straight needle tip of the Crawford needle provides a better angle for threading the catheter upward. Wong, CA. Spinal and Epidural Anesthesia. New York: McGraw-Hill; 2007: 45.

Besides direct trauma to the larynx/trachea -- what are other contraindications to jet ventilation?

The textbook absolute contraindication is damage to the larynx or trachea as you mentioned. Partial airway obstruction is a relative contraindication (it can be utilized as long as appropriate-sized jet ventilator catheters are used). Obstruction below the vocal cords that impairs exhalation is a relative contraindication based on the severity of the obstruction.

What are the anesthetic implications of PKU?

The anesthetic plan for the patient with PKU should be aimed at avoiding any drugs that may promote seizure activity. Large doses of local anesthetics can lower the seizure threshold in these patients. In some cases, very high doses of opioids have been implicated in seizures in patients with epilepsy. Methohexital and meperidinel may also increase the likelihood of epileptiform activity in these patients and may need to be avoided. Because patients with PKU are also more susceptible to vitamin B12 deficiency due to strict dietary restriction. As a result, it may be prudent to avoid the use of nitrous oxide. Some studies indicate an increased sensitivity to narcotics in patients with PKU, although the efficacy of some drugs such as nondepolarizing muscle relaxants may be reduced in patients who are already on anti-seizure medications.

What is the most sensitive indicator of ischemia when the aorta is clamped?

The answer is transesophageal echocardiography. Although TEE and 12-lead ECG have little advantage over preoperative clinical data and two-lead ECG monitoring in noncardiac surgery, the advantage of TEE during cardiac surgery is clear. In one study, TEE detected wall-motion abnormalities in 11 out of 12 patients, while the pulmonary artery occlusive pressure remained unchanged in 10 of them. Additionally, during the period of ischemia, no significant changes occurred in the heart rate or systolic pressure. Yao FF. Anesthesiology: Problem-Oriented Patient Management. 6th ed. Philadelphia: Lippincott, Williams, and Wilkins; 2008: 149.

Why should operating room lights be turned as bright as possible when a laser is in use?

The bright light constricts the pupils and creates a smaller aperture through which a stray laser beam could enter the eye and damage the retina. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1017.

Should ACE inhibitors be continued on the AM of surgery?

The combination of ACE inhibitors and general anesthesia often produces a significant hypotension that is refractory to fluid administration, ephedrine, and phenylephrine. There is a general consensus that ACE inhibitors should be withheld for at least 10 hours prior to the induction of anesthesia. If the patient takes an evening dose, it should be given, but the AM dose should be withheld. If the patient has recently taken an ACE inhibitor and the case must continue, vasopressin should be available to treat refractory hypotension. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 226.

What area of the foot does the deep peroneal nerve supply?

The dorsal skin surface between the first and second toes Moses KP, Banks JC, Nava PB, Petersen D. Atlas of Clinical Gross Anatomy. Philadelphia, PA: Mosby-Elsevier; 2005: 486-574.

How does left ventricular end-diastolic and end-systolic volume change during pregnancy? How does this affect the EF?

The left ventricular end-diastolic volume increases during pregnancy, but there is no change in the end-systolic volume. As a result, the ejection fraction during pregnancy is increased. Chestnut DH, Polley LS, Tsen LC, Wong CA. Chestnut's Obstetric Anesthesia. Philadelphia, PA: Mosby Elsevier; 2009: 17.

How is receptor affinity for a drug related to the potency of a drug?

The lower the affinity of a receptor for a certain drug, the greater the concentration of the drug must be present to form a significant number of drug-receptor complexes. In other words, the lower the affinity, the more of the drug you have to administer to achieve a certain effect. Potency relates the amount of a drug that must be administered to achieve its clinical effect. Fentanil 50-100 micrograms can achieve the same effect as 10 mg of morphine. The dose of fentanil is much lower, which indicates that its potency is higher, and its affinity for opioid receptors is higher. Katzung BG, Masters, SB, & Trevor AJ. Basic and Clinical Pharmacology. 11th ed. New York: McGraw-Hill; 2009: 15.

Antacids increase the gastric fluid volume. Is this a concern with regard to increased risk of aspiration?

The risk of aspiration depends upon both the pH of the fluid in the stomach as well as the volume. The fact that antacids increase the volume of fluid in the stomach, however, does not warrant witholding antacids. It has been shown that the mortality rate of aspiration is increased when small volumes (0.3 mL/kg) of acidic fluid is aspirated compared to larger volumes of buffered solution. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 591.

What information does a dose-response curve provide?

The slope of a dose-response curve demonstrates the rate of increasing effect with an increased dose. The dose-response curve also demonstrates the efficacy, or maximal effect of a drug as well as the potency (ED50). A dose-response curve can also demonstrate variability in drug effect if it measures multiple subjects. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 151.

What degree of hypermagnesemia produces loss of deep tendon reflexes?

The textbooks differ on this, and presumably, so do patients, but you need an answer for the board exam you can go with. Nagelhout states that loss of deep tendon reflexes occurs between a magnesium of 4-7 mg/dL. The Longnecker text states that deep tendon reflexes become lost between 4-6 mg/dL. Both textbooks have been highly reliable thus far and Nagelhout provides the greatest range for patient variability, so I would recommend going with 4-7 mg/dL on this one. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 410. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 203.

What are the most sensitive invasive and non-invasive methods for detecting an air embolism?

The transesophageal echocardiogram is the most sensitive device for detecting venous air embolism. The doppler is, however, the most sensitive non-invasive device for this purpose. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 768-769.

What is the most common test used to diagnose tuberculosis and what are its limitations?

The tuberculin skin test (Mantoux test) is the most common test used to diagnose TB. The test may inaccurately report positive if the patient has been exposed but not infected with TB, has received a bacille Calmette-Guerin vaccine, or been exposed to other species of Mycobacterium, even if there is no bacterial infection at the time of testing. Chest radiographs and sputum smears are more accurate in diagnosing TB. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 727-730.

How does water-immersion in a lithotripsy tub affect cardiac parameters?

There are two possible effects that may be seen from immersion into the lithotripsy tub: 1) an increase in central venous blood volume from the hydrostatic pressure of the water and 2) hypotension due to vasodilation from the warmth of the water. The most common effect to watch for are the effects of increased CVP. Studies have indicated that the central blood volume can increase by as much as 700 mL, an amount that can have serious consequences for patients with congestive heart failure. The CVP and pulmonary artery pressures increase significantly, but the heart rate and arterial pressure typically are not altered by immersion. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 718. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 1364-1365.

What are the two major physiologic factors that can result in a greater initial response to a drug in elderly patients?

They have a decreased vascular volume, which results in a high initial plasma concentration of the drug. They also have decreased plasma protein levels which produces an increased concentration of the free form of the drug that exerts pharmacologic action. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1214.

What is the recommended position in which tonsillectomy patients should be placed postoperatively and why?

They should be placed in the lateral position with their head slightly down to protect the airway from bleeding or gastric aspiration until they are fully awake. This is referred to as the 'tonsillar' position. Jaffe RA, Samuels SI. Anesthesiologist's Manual of Surgical Procedures. 4th ed. Philadelphia, PA: Lippincott Williams and Wilkins, 2009: 206.

How would patient pH affect the clinical action of thiopental?

Thiopental is an acidic compound. The more acidotic the patient becomes, the more nonionized the drug becomes. As a result, more of the drug is in the lipid-soluble state that can cross the blood-brain barrier and exert a clinical effect. In short, acidosis increases the effect of thiopental. Alkalosis decreases the effect of thiopental. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 121.

What drugs should be avoided in patients with porphyria?

This is a question I have been asked several times. The answer that comes to mind immediately, is that thiopental should be avoided. You must remember, however, that sometimes the most popular answer is not even available on the board exam as an option. With that in mind, when you see lists in a table in your textbook (such as contraindicated drugs in porphyria), be sure that you write the list down and commit it to memory before boards! Nitrous oxide, neostigmine, morphine, fentanyl, succinylcholine, pancuronium, lidocaine, and propofol are considered safe for use in patients with porphyria. Ketorolac, thiopental, etomidate, pentazocine, methohexital, and nifedipine should all be avoided. For my boards, I used the mnemonic "a patient with porphyria should avoid being a KEPT MAN" for Ketorolac, Etomidate, Pentazocine, Thiopental, Methohextial And Nifidepine". Yeah, I know it's stupid, but I remembered it and that's all that matters!

Do platelets have to be matched to the recipient's blood type?

This is a question I received today that is actually explained in the rationale of one of the PACES questions (hmmmm...there's an advertisement here, but I won't indulge it right now). Anyway, the answer is No. It is preferable to match platelets to the recipient's blood type, but not necessary. Normally, platelets survive about 1-7 days after administration and ABO matching may prolong their survival. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 1895. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 699.

Are PACES Questions Actual Board Questions?

This is a question that was brought to my attention today. I am proud to say that none of the questions that appear in the PACES program are derived from actual board exams. I suppose that sounds funny, as some of the competing board review solutions are known for distributing material based on reports from students who took the exam. I can understand how you might prefer to have actual questions, which would increase your chances of passing. I mean, who wouldn't want to essentially have a copy of the test? I, however, don't believe that's the best tact. In fact, there was a dramatic controversy at the very school I attended that, according to the program director involved, resulted in the seizure and forensic analysis of computers and the near revocation of newly acquired nurse anesthesia licenses because students were found in possession of actual board questions. That happened to the class ahead of me and the event stuck in my consciousness. It is actually one of the main reasons I decided to create PACES. I wanted to create a program that helped students train for the exam that would not result in receiving a Federal indictment for anyone involved. A couple of students in the past have offered to send me questions that appeared on boards and I refused. In fact, last year, a student raised a ruckus with me and demanded a full refund because I did not provide actual board questions while another competing review system did. I don't think he even realized the significance of what he was saying. When you sit down to take the exam, you must first agree to a Nondisclosure Agreement, in which you promise not to divulge any of the information contained within the exam with any other persons. Here is the statement that typically accompanies copyrighted material: "Federal law provides severe civil and criminal penalties for the unauthorized reproduction, distribution, or exhibition of copyrighted materials. Criminal copyright infringement is investigated by the FBI. " My understanding is that in the event I described above, the FBI WAS involved. Scary, huh? Not only could you lose your license, but if you were convicted of criminal copyright infringement you face a possible maximum penalty of up to five years in prison and up to a $250,000 monetary fine. So, what's the take home message here? If someone asks you what was on your boards, especially persons associated with a commercial board review product, DON'T ANSWER. They might make a nicer profit off their product, but everyone involved could face criminal and civil charges...and that includes you. Also, I would avoid the use of any product that provides actual board questions or purports to do the same as you could be involved in any resulting investigations. Even if you did not lose your license, you might have to spend time in depositions. It's just not worth it. Although PACES doesn't provide actual board questions, I try to create detailed rationales, questions asked from multiple angles, and supporting material so that the topic is covered adequately. My goal is to provide you with the knowledge required to answer ANY question on that topic. I am committed to helping you pass boards in a fair and ethical manner. Peter Stallo

Where does the artery of Adamkiewicz originate?

This is a tricky question because the answer varies between sources. (Barash states it originates between T11 and T12 while Nagelhout says it appears between T8 and L2). So, the question I was posed with today was "Which answer should I use on boards?" Because it is an anatomical feature, there is a great deal of variation in where and how it appears. For example, the artery of Adamkiewicz originates on the left side in about 75% of people and on the right in about 25%. The most complete answer is the one that presents the broadest range of appearance, but that is not necessarily the one that the question writers used. When there is conflict between textbooks, I defer to Nagelhout (remember that Dr. Nagelhout is on the exam writing board). I figure, if she is on the board, then that is the source most likely to be presumed accurate for the exam.

Can you recommend a site to get all the laws in my head?

This is how i remember it: Boyles Law- At a constant temp, the volume of a gas is inversley related to it's pressure. Remember- BOYLES BALLOON As a balloon rises, the air pressure decreases around the balloon and the pressure inside of the balloon increases. At a constant temperature, increasing one of the variables will cause the other to decrease. (Variables volume and pressure) Daltons Law- Total pressure of a gas mixture is the sum of all the individual pressures of the individual gasses. Look at it like this: I have 50 mmhg of gas 1 and 50 mmhg of gas 2 in my atmosphere. The total pressure will be 100 mmhg. Think- DALTON'S GANG. Charles Law- When pressure is constant, gas volume changes with temperature. I leave an oxygen tank out in the hot sun for a few hours and the volume of gas in the tank will increase. Think- CHARLES CELSIUS Gay Lussacs Law- Think- CHARLES GAY BROTHER. Nearly like Charles law but states pressure changes with temperature. For example; we leave the same oxygen tank out in the sun and the pressure will increase within the take as temperature increases. Charles- Volume Gays-Pressure Henry's Law- The weight of a gas is in a dissolved liquid is proportional to the weight of a gas above the liquid. Thik of a bottle of beer. When you open it what happens? Right, carbon dioxide quickly leaves the solution once the top is taken off. The weight of the atmosphere is less than the weight of the gas dissolved in a bottle of beer thus gas moves out of the beer bottle into the atmosphere. This also explains the basic principle behind the bends. Think- HENRYS HEINEKEN. Grahams Law- Gas will want to move from areas of high concentration to areas of low concentration right? However, more dense gas will move slower than less dense gas. Makes sense. Did you learn the triangle mnemonic? Could These Girls Possibly Be Virgins Starting with right hand corner of triangle and going clockwise. C-charles T-temp G- Gay lus P-pressure B-boyle V-Volume also remember Boil for Boyles law = Temp constant "Charles in Charge was on TV" which helped me remember that Charles' law was temperature and volume, and "Boyles law doesn't boil" so that I could remember that it did not contain temperature, and therefore only pressure and volume. I can't really post the one about Gay-Lussac's law here, but maybe I can come up with an acceptable substitute. I think, however, that Christina's method is the most effective because one simple mnemonic explains them all. I had trouble remembering the triangle when I was in school, but I won't forget it now!

Where in the body are COX-1 and COX-2 receptors located?

This one was more complicated than I thought: COX-1 receptors are widespread throughout the entire body, but appears to be more concentrated in the kidneys, gastric mucosa, platelets, and endothelium. COX-2 receptors are present in the kidneys and central nervous system and can be synthesized in response to inflammatory processes. After several hours of peripheral inflammation, proteins and peptides released into circulation from the neurons in the inflamed tissue induce a synthesis of COX-2 receptors in the neurons of the dorsal horn. Humoral factors released from the site of inflammation stimulate endothelial and meningeal cells to produce interleukin-1-beta which in turn, stimulates the production of COX-2 receptors. This upregulation of COX-2 receptors by inflammation is not localized, but widespread throughout the CNS. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 1244. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 2012.

What is the incidence of mitral valve prolapse?

This question arrived as the result of a disparity between the PACES software and information provided by a competitor as the incidence I report is significantly less. I love this question, because it gives me a chance to show off the importance of all the work I put into updating the references for the PACES questions. Anyway, enough tooting my own horn--here's the answer: Mitral valve prolapse was previously estimated to occur in about 5% of the general population and 15% of women, but newer data demonstrates that the actual incidence is between 1.6% and 2.4% in the U.S. population. Morgan GE, Mikhail MS, Murray MJ. Clinical Anesthesiology. 4th ed. New York, NY: McGraw-Hill; 2006: 472. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 501.

What is the difference between these legal terms: general damages, special damages, and punitive damages?

Three types of damages may be sought for in a civil lawsuit: general damages, special damages, and punitive damages. General damages result directly from the injury and include reimbursement for pain and suffering. Special damages that occur as a result of the injury, such as lost wages, medical expenses, and funeral expenses. Punitive damages are rare in medical malpractice cases, but are intended to punish the wrongdoer for the negligence that led to the damage to the plaintiff. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 5th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2006: 100.

You're about ot perform an awake fiberoptic intubation on a c-spine injured pt. Can you use transtracheal anesthesia?

Topical anesthesia may be used, but transtracheal anesthesia must be avoided as these patients are likely to have a full stomach. Transtracheal anesthesia increases the risk for aspiration. Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saunders Company; 2010: 887.

I am trying to calculate PaO2 based on a patient's age. However, the formula in M&M( pg. 559) and the formula provided by Prodigy( Math for Anesthetists Book one) do not produce the same answer. Anyone know how to reconcile the two?

Yep. The formula in M&M is different from the one that I decided on using for the review program. I use the one provided in Nagelhout's Nurse Anesthesia (Nagelhout JJ, Zaglaniczny KL. Nurse Anesthesia. 4th ed. Philadelphia, PA: WB Saun...ders Company; 2010: 1212.) The formula that I use is indicated in the PACES Library Workbook entitled Estimating PaO2 Based on Age. It provides step-by-step instructions and several practice problems. Anyway, I had to choose one formula over the other. My decision to use the Nagelhout formula is that this book is specifically dedicated to nurse anesthesia, which I think increases the odds that it would be used as the resource of choice over M&M which is not specific for nurse anesthetists. Your instructors may prefer to use M&M for that calculation, but I believe the best bet for boards is increasingly going to become Nagelhout.

Does epidural fentanyl decrease MAC?

Yes, epidural fentanyl decreases MAC. In fact, fentanyl given epidurally decreases MAC by a greater extent than equal doses of fentanyl given intravenously. Barash PG, Cullen BF, Stoelting RK. Clinical Anesthesia. 6th ed. Philadelphia, PA: Lippincott Williams and Wilkins; 2009: 477.

How should you adjust your anesthetic for the patient with primary hyperparathyroidism?

Your anesthetic should be aimed at dealing with underlying hypercalcemia. Because of this, hydration with normal saline and monitoring of urinary output is essential. Because hypercalcemia is associated with somnolence, the anesthetic requirement may be decreased. If personality changes due to chronic hypercalcemia are present, then ketamine may need to be avoided. Baseline skeletal weakness may necessitate a decreased dose of nondepolarizing muscle relaxants, however the increased calcium can antagonize muscle relaxants--in short, hyperparathyroidism is associated with an increased sensitivity to succinylcholine and a resistance to nondepolarizing muscle relaxants. Acidosis increases the serum calcium level, so hypoventilation should be avoided. As with thyroidectomy, there is a risk of damage to the recurrent laryngeal nerve during surgery, so a Nim(Registered) tube or similar device should be used to monitor nerve function during surgery. It is important to position patients with a risk of pathologic fractures carefully. Stoelting RK, Dierdorf SF. Anesthesia & Co-Existing Diseases. 5th ed. New York, NY: Churchill-Livingston; 2008: 400-401. Longnecker DE. Anesthesiology. New York: McGraw-Hill; 2008: 1604.