Monday, April 30, 2018

Auto-PEEP and Physical Exam

Q: Physical examination can exclude but cannot confirm auto-PEEP?

A) True
B) False

Answer: False

Physical exam of the chest in patients who are on mechanical ventilation can confirm auto-PEEP but cannot exclude auto-PEEP. Careful auscultation, as well as palpation, may demonstrate continued expiratory airflow from the previous breath when the next breath is triggered by a mechanical ventilator.


Kress JP, O'Connor MF, Schmidt GA. Clinical examination reliably detects intrinsic positive end-expiratory pressure in critically ill, mechanically ventilated patients. Am J Respir Crit Care Med 1999; 159:290.

Sunday, April 29, 2018

Lagging of pulse-ox

Q: Pulse-oximetry reading (finger probe) lags behind the central arterial circulation?

A) True
B) False

Answer: True (A)

Although sound very simple and obvious but this is a critical point in intensive care unit's patients where other clinical signs of deterioration precede before desaturation. This lagging of pulse-ox desaturation may put an unexperienced house-staff under false sense of comfort and golden moment of intervention may get lost.


1. Weingart SD, Levitan RM. Preoxygenation and prevention of desaturation during emergency airway management. Ann Emerg Med 2012; 59:165.

2. Ding ZN, Shibata K, Yamamoto K, et al. Decreased circulation time in the upper limb reduces the lag time of the finger pulse oximeter response. Can J Anaesth 1992; 39:87.

Saturday, April 28, 2018

marker of mortality in heart-lung transplantation

Q: Which of the following marker is a good predictor of mortality in patients with severe pulmonary hypertension who undergoes heart-lung transplant?

A) Thrombocytopenia
B) Hyperbilirubinemia
C) Hypercalcium 
D) High LDH  level
E) baseline PO2 on room air prior to transplant

Answer: B

End stage pulmonary hypertension  results in hyperbilirubinemia due to chronic passive hepatic congestion. Persistent hyperbilirubinemia has been found to be a good marker of postoperative mortality in heart-lung transplant recipients due to end stage pulmonary hypertension.



Reichenberger F, Pepke-Zaba J, McNeil K, et al. Atrial septostomy in the treatment of severe pulmonary arterial hypertension. Thorax 2003; 58:797.

Friday, April 27, 2018

Hemiparesis or reflex asymmetry which alternates from side to side

Q: Hemiparesis or reflex asymmetry which alternates from side to side is usually the characteristic of which encephalopathy? 

A) Uremic encephalopathy
B) Wernicke's encephalopathy
C) Hepatic encephalopathy
D) post stroke encephalopathy
E) Post-transplant encephalopathy

Answer: A

Although not commonly present, hemiparesis or reflex asymmetry may occur in uremic encephalopathy. It quickly gets reversed with hemodialysis. If occurs, it tends to alternate from side to side.



Chen R, Young GB. Metabolic Encephalopathies. In: Baillere's Clinical Neurology, Bolton CF, Young GB (Eds), Balliere Tindall, London p.577.

Thursday, April 26, 2018

Silicone embolism syndrome

Q: Silicone embolism syndrome is a clinical diagnosis?

A) True
B) False

Answer: A (True)

Silicone embolism syndrome which may occur after silicone injection for cosmetic and/or therapeutic therapy. It is very much like fat embolism syndrome and has the clinical triad of
  • hypoxemia, 
  • fever, and 
  • a petechial rash

The most devastating manifestation can be diffuse alveolar damage.

Treatment is supportive.


1. Chung KY, Kim SH, Kwon IH, et al. Clinicopathologic review of pulmonary silicone embolism with special emphasis on the resultant histologic diversity in the lung--a review of five cases. Yonsei Med J 2002; 43:152. 

2. Schmid A, Tzur A, Leshko L, Krieger BP. Silicone embolism syndrome: a case report, review of the literature, and comparison with fat embolism syndrome. Chest 2005; 127:2276.

Wednesday, April 25, 2018

Risk correction in Fat Embolism Syndrome

Q: Early operative correction of fractures increases the chance of fat embolism syndrome (FES)?

A) True
B) False

Answer: B (False)

Few measures which decrease the chances of FES after long bone trauma include early immobilization of fracture, early operative correction, intraosseous pressure limitation and arguably steroids.


1. Riska EB, Myllynen P. Fat embolism in patients with multiple injuries. J Trauma 1982; 22:891. 

2. Kröpfl A, Davies J, Berger U, et al. Intramedullary pressure and bone marrow fat extravasation in reamed and unreamed femoral nailing. J Orthop Res 1999; 17:261. 

3. Sen RK, Tripathy SK, Krishnan V. Role of corticosteroid as a prophylactic measure in fat embolism syndrome: a literature review. Musculoskelet Surg 2012; 96:1.

Tuesday, April 24, 2018

10:70:70 rule of cryoprecipitate

Q; What is the 10:70:70 rule of cryoprecipitate? 

 Answer: Ten units of cryoprecipitate will raise the fibrinogen level approximately 70 mg/dL in a 70 kg recipient. 


 Levy JH, Welsby I, Goodnough LT. Fibrinogen as a therapeutic target for bleeding: a review of critical levels and replacement therapy. Transfusion 2014; 54:1389.

Monday, April 23, 2018

Physical exam

Q: 78 year old male in ICU is recovering from pneumonia and is waiting for transfer to floor. All "lines and tubes" have been removed. Patient starts complaining of lower abdominal pain. Nurse informed you that there is no urine output since last 8 hours. Distended bladder is suspected. Physical exam with percussion over urinary bladder area, if distended bladder is present should be (select one)

A) dull
B) tympanic

Answer: Dull

Objective of above question is to highlight the importance of basic physical exam in ICU. Percussion easily distinguishes between air (tympanic sound) and mass or fluid (dull sound). It would not be appropriate to directly jump to a radiological workup. Proper collection of information (history) and physical exam should continue to be the initial steps of patient management.

Sunday, April 22, 2018

ETT depth

Scenario; 54-year-old male is intubated in ICU after he failed a trial of BiPAP from community-acquired pneumonia. Due to patient's long stature, nerdy resident calculated the length of endotracheal tube (ETT) depth to be at 26 cm at lips. After ten minutes of intubation, the nurse informed you about frequent ventricular arrhythmia on the monitor which appears to be mostly Premature Ventricular Contractions (PVCs).

Explanation: PVCs is a frequent manifestation if ETT is touching carina and call for adjustment. A plethora of literature has been written and various formulas have been developed to calculate the exact depth of ETT but none of them have done well in real life. Rule of thumb so far has worked satisfactorily with 21 cm for females or 23 cm for males at lips. Adjustment with physical exam (auscultation of bilateral breath sounds) and CXR verification is still a standard of care.



Burman SO, Gibson TC, Chir B. Bronchoscopy and cardiorespiratory reflexes. Ann Surg. 1963;157:134–41

Saturday, April 21, 2018

TCA poisoning

Q: Sodium bicarbonate is indicated in patients with Tricyclic Antidepressants (TCA) poisoning who develop? 

A) >100 msec 
B) Ventricular arrhythmia
C) Unspecified arrhythmia
D) Unexplained hypotension
E) All of the above

Answer: E

Sodium bicarbonate is the standard of care and recommended initial therapy in TCA toxicity to avoid any cardiac complication. It is cheap, effective and easy to institute. Interestingly, even if widened QRS interval does not show narrowing on EKG, sodium bicarbonate infusion is recommended to be continued, as lower serum pH potentiates the poisoning of TCA. Recommended target pH is 7.50 to 7.55. High serum pH favors the non-ionized form of the drug, making it less available to bind to sodium channels. Also, increase extracellular sodium concentration increases the electrochemical gradient across myocardium cell membrane, attenuating the TCA-induced blockade of rapid sodium channels.



1. Hoffman JR, Votey SR, Bayer M, Silver L. Effect of hypertonic sodium bicarbonate in the treatment of moderate-to-severe cyclic antidepressant overdose. Am J Emerg Med 1993; 11:336. 

2. Bruccoleri RE, Burns MM. A Literature Review of the Use of Sodium Bicarbonate for the Treatment of QRS Widening. J Med Toxicol 2016; 12:121.

Friday, April 20, 2018

premature occlusion of the coronary artery stents

Q: All of the following are the risk factors for the premature occlusion of the coronary artery stents except?

A) Premature cessation of dual anti-platelet therapy 

B) Smaller stent length 
C) Smaller vessel caliber
D) Left ventricular dysfunction 
E) Nonionic contrast media

Answer:  B

Premature cessation of dual anti-platelet therapy is the most common and the well known cause for the premature occlusion of the coronary artery stents but there is a long laundry list for this potentially life-threatening complication including proximal left anterior descending (LAD) stenting, side-branch stenting, diabetes mellitus, end-stage renal disease (ESRD), greater stent length, smaller vessel caliber, left ventricular dysfunction, use of nonionic contrast media, cocaine use, emergent stent placement, no aspirin at the time of the procedure, malignancy, multivessel disease.


1. Daemen J, Wenaweser P, Tsuchida K, et al. Early and late coronary stent thrombosis of sirolimus-eluting and paclitaxel-eluting stents in routine clinical practice: data from a large two-institutional cohort study. Lancet 2007; 369:667. 

2. Lagerqvist B, Carlsson J, Fröbert O, et al. Stent thrombosis in Sweden: a report from the Swedish Coronary Angiography and Angioplasty Registry. Circ Cardiovasc Interv 2009; 2:401. 

3.  Schühlen H, Kastrati A, Pache J, et al. Incidence of thrombotic occlusion and major adverse cardiac events between two and four weeks after coronary stent placement: analysis of 5,678 patients with a four-week ticlopidine regimen. J Am Coll Cardiol 2001; 37:2066. 

4. Scheller B, Hennen B, Pohl A, et al. Acute and subacute stent occlusion; risk-reduction by ionic contrast media. Eur Heart J 2001; 22:385.

Thursday, April 19, 2018

PDE5 inhibitors

Q: PDE5 inhibitors (Sildenafil, tadalafil or vardenafil) are now increasing used in ICU for the management of pulmonary hypertension. Their mechansim of action is? 

 A) Prolong the vasodilatory effect of nitric oxide 
B) Stimulates the nitric oxide receptor 
C) Selective antagonist of type A endothelin-1 receptor 
D) Nonselective endothelin receptor antagonist 
E) unexplained (found accidentally in patients with erectile dysfunction) 


Phosphodiesterase type 5 (PDE5) inhibitors prolong the vasodilatory effect of nitric oxide.

(Choice B) Riociguat is a Guanylate Cyclase stimulant (sGC) which increases the sensitivity of sGC to endogenous nitric oxide (NO) as well as directly stimulate the receptor to mimic the action of NO.

(choice C) Ambrisentan is an oral selective type A endothelin-1 receptor antagonist.

(Choice D) Bosentan is an oral nonselective endothelin receptor antagonist.



Galiè N, Humbert M, Vachiery JL, et al. 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT). Eur Heart J 2016; 37:67.

Wednesday, April 18, 2018


Q: Digoxin despite having normal (therapeutic) level can cause delirium? 

A) True 
B) False 

 Answer: A Objective of above question is to highlight the complexity of delirium. Any drug, environmental discordance, pain or any underlying disease process can cause delirium. 

 Those medications which require therapeutic level monitoring despite being at appropriate dose can still be the cause of delirium. 


Francis J. Drug-induced delirium: Diagnosis and treatment. CNS Drugs 1996; 5:103.

Tuesday, April 17, 2018

laryngeal injury

Q: All of the following are risk factors for laryngeal injury via Endotracheal tube (ETT) except

A) Prolonged intubation 
B) Traumatic intubation 
C) Using a muscle relaxant during intubation
D) Unplanned extubation 
E) Presence of a nasogastric tube

Answer: C

The objective of above question is to highlight the importance of proper skills and techniques to be used during intubation. It is not uncommon to see that medical staff skip the use of a muscle relaxant during intubation for various reasons including unresponsiveness of a patient, fear of increasing the risk of myopathy, hyperkalemia, difficult intubation or desaturation.

Muscle relaxants should be employed during intubation unless absolutely contraindicated or risk is too high.


1. Tadié JM, Behm E, Lecuyer L, et al. Post-intubation laryngeal injuries and extubation failure: a fiberoptic endoscopic study. Intensive Care Med 2010; 36:991. 

2. Santos PM, Afrassiabi A, Weymuller EA Jr. Risk factors associated with prolonged intubation and laryngeal injury. Otolaryngol Head Neck Surg 1994; 111:453. 

3. Colton House J, Noordzij JP, Murgia B, Langmore S. Laryngeal injury from prolonged intubation: a prospective analysis of contributing factors. Laryngoscope 2011; 121:596.

4. Friedman M, Baim H, Shelton V, et al. Laryngeal injuries secondary to nasogastric tubes. Ann Otol Rhinol Laryngol 1981; 90:469.  

Monday, April 16, 2018

CNS viral escape syndrome

Q: What is CNS viral escape syndrome?

 Answer: CNS viral escape syndrome is an HIV related phenomenon in which despite compliant treatment with antiretroviral therapy (ART), patients develop neurological deficits popularly known as HAND (HIV-associated neurocognitive disorders). Although viral load stays low in the plasma there is evidence of CNS HIV replication in the cerebrospinal fluid (CSF). This is due to drug resistance to the virus in the CSF. 

HAND is mostly characterized by difficulty with attention, lagging of memory, lack of cerebrating decisions and slowing down of cognitive and motor skills. 



1. Peluso MJ, Ferretti F, Peterson J, et al. Cerebrospinal fluid HIV escape associated with progressive neurologic dysfunction in patients on antiretroviral therapy with well controlled plasma viral load. AIDS 2012; 26:1765. 

2. Canestri A, Lescure FX, Jaureguiberry S, et al. Discordance between cerebral spinal fluid and plasma HIV replication in patients with neurological symptoms who are receiving suppressive antiretroviral therapy. Clin Infect Dis 2010; 50:773. 

Sunday, April 15, 2018

Delta Toxin

Q: What is Delta toxin?

Answer: Delta toxin is a hemolytic peptide secreted by Staphylococcus aureus. This toxin is also known as Delta-lysin or septicolysin as it is lytic to cells by solubilization of their membranes. Also, it has direct and indirect effects on the activity of neutrophils and monocytes which confers to its proinflammatory property. 



 1. Dhople, V. M. and Nagaraj, R. Prot. Eng. 8, 315 (1995), Dhople, V. M. and Nagaraj, R. Peptides 26, 217 (2005). Send to J Infect Dis. 1997 Dec;176(6):1531-7. 

2. Schmitz FJ, Veldkamp KE, Van Kessel KP, Verhoef J, Van Strijp JA. Delta-toxin from Staphylococcus aureus as a costimulator of human neutrophil oxidative burst. J Infect Dis. 1997 Dec;176(6):1531-7. 

Saturday, April 14, 2018


Q: which of the following group of antibiotics is a best bet against extended-spectrum beta-lactamases (ESBLs) producing organisms? 

 A) Penicillins
 B) Cephalosporins
 C) Monobactams 
 D) Carbapenems 
 E) Fluoroquinolones

Answer: D

Extended-spectrum beta-lactamases (ESBL) are enzymes that confer resistance to beta-lactam antibiotics which include penicillins, cephalosporins, and the monobactams. Carbapenems have been found to be the best treatment options in most of the studies. In case of increase risk from carbapenems such as in pregnancy or patients with underlying history of seizure, meropenem is considered as a good choice. Also, doripenem is another new promising carbapenem.



1.  Tamma PD, Han JH, Rock C, et al. Carbapenem therapy is associated with improved survival compared with piperacillin-tazobactam for patients with extended-spectrum β-lactamase bacteremia. Clin Infect Dis 2015; 60:1319.

2. Kaniga K, Flamm R, Tong SY, et al. Worldwide experience with the use of doripenem against extended-spectrum-beta-lactamase-producing and ciprofloxacin-resistant Enterobacteriaceae: analysis of six phase 3 clinical studies. Antimicrob Agents Chemother 2010; 54:2119. 

Friday, April 13, 2018

Liver laceration

Q: Which of the following is the most reliable parameter of grading liver laceration/injury?

A) Aspartate aminotransferase (AST)
B) Alanine aminotransferase (ALT)
C) Level of Anemia
D) Blood Urea Nitrogen (BUN)
E) None of the above

Answer: E

None of the laboratory parameters are found to correlate well with the level of hepatic injury. This is a clinical diagnosis put together by history, physical exam and radiological workup such as a computed tomography (CT) with IV contrast, Focused Assessment with Sonography in Trauma (FAST), diagnostic peritoneal lavage (DPL) or diagnostic peritoneal aspiration (DPA) if clinically indicated, magnetic resonance imaging (MRI), and selectively arteriography.


1. Koyama T, Hamada H, Nishida M, et al. Defining the optimal cut-off values for liver enzymes in diagnosing blunt liver injury. BMC Res Notes 2016; 9:41.

Thursday, April 12, 2018


Q: At what level of low haptoglobin it is considered due to hemolytic anemia?

 Answer:  Haptoglobin is an acute-phase reactant which goes up in infection and inflammation. But in clinical practice it is mostly used to predict hemolysis by it's low level. There are other reasons for low heptoglobin such as abdominal trauma and congenital ahaptoglobinemia but if haptoglobin level is less than 25 mg/dL, it is due to hemolysis proved otherwise. This should be read in conjunction with other labs such as high LDH and bilirubin but undetectable or extremely low haptoglobin itself is a good marker to consider hemolysis.

Normal haptoglobin level is 30-200 mg/dL.



1. Marchand A, Galen RS, Van Lente F. The predictive value of serum haptoglobin in hemolytic disease. JAMA 1980; 243:1909. 

2. Stahl WM. Acute phase protein response to tissue injury. Crit Care Med 1987; 15:545.

Wednesday, April 11, 2018

Half life of Protamine

Q: The half life of protamine is?

A) 5 minutes
B) 15 minutes
C) 30 minutes
D) 60 minutes
E) It correlates with heparin level in the plasma

Answer: A

Protamine is a known reversal of heparin. It has a very short  half-life of about five minutes. This information is clinically significant as recurrent anticoagulation may occur after initial reversal of heparin, and may require re-dosing of protamine. 


Butterworth J, Lin YA, Prielipp RC, Bennett J, Hammon JW, James RL. Rapid disappearance of protamine in adults undergoing cardiac operation with cardiopulmonary bypass. .Ann Thorac Surg. 2002 Nov;74(5):1589-95.

Tuesday, April 10, 2018

Smoker's Paradox

Q; What is "smoker’s paradox"?

Answer: Smoker's paradox is a troubling phenomenon in cardiovascular patients. A population of patients who are nonsmokers may tend to have decrease response to clopidogrel, an essential treatment in most "stented patients". Smoking stimulates CYP1A2 and so enhances platelet inhibition by clopidogrel. Interestingly, once smoking is stopped, which is an universal recommendation, this benefit is lost.


1. Desai NR, Mega JL, Jiang S, et al. Interaction between cigarette smoking and clinical benefit of clopidogrel. J Am Coll Cardiol 2009; 53:1273. 

2. Gurbel PA, Nolin TD, Tantry US. Clopidogrel efficacy and cigarette smoking status. JAMA 2012; 307:2495. 

3. The association of cigarette smoking with enhanced platelet inhibition by clopidogrel. J Am Coll Cardiol 2008; 52:531. 

4. Park KW, Kang SH, Kang J, et al. Enhanced clopidogrel response in smokers is reversed after discontinuation as assessed by VerifyNow assay: additional evidence for the concept of 'smokers' paradox'. Heart 2012; 98:1000. 

Monday, April 9, 2018

Pain in metastatic pancreatic cancer

Q: 52 year old male with a known diagnosis of metastatic pancreatic cancer is transferred from oncology floor after requiring intubation due to narcotic overdose. This is the second time patient required intubation due to the similar reason. Which of the following is a good option to relieve pain and prevent further such episodes?

A) Celiac plexus neurolysis (CPN)

B) Request patient to sign Do Not Resuscitate (DNR) papers
C) Tracheostomy
D) Placement of a stent across the area of biliary tract obstruction
E) Gabapentin

Answer: A

Celiac plexus neurolysis (CPN) has been found to be more effective than any other modality to relieve pain from metastatic pancreatic cancer. Other closest option is local radiation. It should be understood that CPN is not a denervation process, rather it inhibits synaptic pathways within the plexus. 

Choice B is unethical.
Choice C will not bring any comfort from pain.
Choice D may provide relief from pruritis and jaundice but not from pain.
Choice E may help but not be very effective in this scenario.



1. Wong GY, Schroeder DR, Carns PE, et al. Effect of neurolytic celiac plexus block on pain relief, quality of life, and survival in patients with unresectable pancreatic cancer: a randomized controlled trial. JAMA 2004; 291:1092.  

2. Amr YM, Makharita MY. Neurolytic sympathectomy in the management of cancer pain-time effect: a prospective, randomized multicenter study. J Pain Symptom Manage 2014; 48:944.

Sunday, April 8, 2018

Berkson’s Bias

Q: What is Berkson’s Bias? 

Answer: Berkson’s Bias also known as Berkson Fallacy or Berksonian Bias was proposed in 1946 by Joseph Berkson. According to his theory, any study conducted in a medical care setting is exposed to bias as both exposure and disease status is affected. This is an extremely important form of selection bias which can potentially cloud any prospective or retrospective study. 

References/further readings:

1. Berkson J. Limitations of the Application of Fourfold Table Analysis to Hospital Data. Biometrics Bulletin. 1946;2(3):47–53.

2. Walter SD. Berkson's bias and its control in epidemiologic studies. J Chronic Dis 1980;33:721–25

3. Roberts RS, Spitzer WO, Delmore T, Sackett DL. An empirical demonstration of Berkson's bias. J Chronic Dis 1978;31:119–28

4. Schwartzbaum J, Ahlbom A, Feychting M. Berkson's bias reviewed. Eur J Epidemiol 2003;18:1109–12

5. Westreich D. Berkson's bias, selection bias, and missing data. Epidemiology 2012;23:159–64

Saturday, April 7, 2018

Steroid myopathy

Q: Concomitant use of which of the following medications decrease the intensity of dexamethasone induced myopathy?

A) Neuro-muscular blockers
B) Phenytoin
C) Erythromycin
D) Proton Pump Inhibitors 
E) Propofol

Answer: B

Patients with brain tumor usually use dexamethasone and phenytoin concomitantly to reduce vasogenic edema and risk of seizures respectively and get the unintended benefit of interaction between steroid and phenytoin. This interaction is due to the induction of hepatic metabolism of dexamethasone by phenytoin. On the reverse side, phenytoin level needs to be monitored as it may have an exaggerated effect.


Pharm.D. Lisa A.Lawson, Pharm.D. Robert A.Blouin, Ph.D.Randal B.Smith Pharm.D. Robert P.Rapp, M.D. A. ByronYoung - Phenytoin-dexamethasone interaction: A previously unreported observation - Surgical Neurology Volume 16, Issue 1, July 1981, Pages 23-24 

Friday, April 6, 2018

GM-CSF connection

Q: 52 year old male is admitted to ICU with shortness of breath. Patient has a previous history of leukemia and  bone marrow transplantation. Pulmonologist look at the admitting CXR with alveolar opacities in mid and lower lung zones in a "bat wing distribution". Which of the following is the most likely diagnosis?

A) Pulmonary alveolar proteinosis (PAP)
B) Acute respiratory distress syndrome (ARDS)
C) Chronic Obstructive Pulmonary Disease (COPD) 
D) Cystic Fibrosis (CF)
E) Idiopathic Pulmonary Fibrosis (IPF)

Answer: A

The objective of the above question is to highlight the association between PAP and leukemia via GM-CSF deficiency or dysfunction. Pulmonary alveolar proteinosis (PAP) is a product of accumulation of lipoproteinaceous material in the distal air spaces. Classic CXR presentation is a "bat wing distribution" with bilateral symmetric alveolar opacities located centrally in mid and lower lung zones. 



1. Tsushima K, Koyama S, Saitou H, et al. Pulmonary alveolar proteinosis in a patient with chronic myelogenous leukemia. Respiration 1999; 66:173. 

2. Ohmachi K, Ogiya D, Morita F, et al. Secondary pulmonary alveolar proteinosis in a patient with chronic myeloid leukemia in the accelerated phase. Tokai J Exp Clin Med 2008; 33:146. 

3. Yoshimura M, Kojima K, Tomimasu R, et al. ABL tyrosine kinase inhibitor-induced pulmonary alveolar proteinosis in chronic myeloid leukemia. Int J Hematol 2014; 100:611.

Thursday, April 5, 2018

antimicrobials in severe babesiosis

Q: All of the following antimicrobials are found to be effective in the treatment of severe babesiosis except?

A) Azithromycin 
B) Atovaquone
C) Clindamycin 
D) Levofloxacin
E) Quinine 

Answer: D

The most commonly used drug regimen for severe babesiosis is intravenous azithromycin plus oral atovaquone. Intravenous clindamycin plus oral quinine can be used as an alternative treatment. Therapy should be guided by the level of parasitemia and blood smears. 

Red blood cell exchange transfusion should be considered as an immediate life-saving therapy or if antimicrobial therapy fails.


1. Vannier E, Krause PJ. Human babesiosis. N Engl J Med 2012; 366:2397. 

2.  Sanchez E, Vannier E, Wormser GP, Hu LT. Diagnosis, Treatment, and Prevention of Lyme Disease, Human Granulocytic Anaplasmosis, and Babesiosis: A Review. JAMA 2016; 315:1767. 

3. Kletsova EA, Spitzer ED, Fries BC, Marcos LA. Babesiosis in Long Island: review of 62 cases focusing on treatment with azithromycin and atovaquone. Ann Clin Microbiol Antimicrob 2017; 16:26.

Wednesday, April 4, 2018

NC and FiO2 oxygen conversion

Q: 6 L per minute of oxygen via low flow nasal cannula (NC) is approximately equal to?

A) 28% FiO2 of oxygen
B) 35% FiO2 of oxygen
C) 45% FiO2 of oxygen
D) 60% FiO2 of oxygen
E) It is hard to compare equivalency between NC and FiO2 level of oxygen

Answer:  C

Actually, there is a calculator developed to find equivalency of NC and FiO2 level of oxygen. This may be of help in converting or weaning patients from mask ventilation to nasal cannula.

Calculators can be found online but a simple rule of thumb is that the fraction of oxygen that is inspired (above 2I%) increases by 4% for every additional liter of oxygen flow administered.


AARC Clinical Practice Guideline, In Vitro pH and Blood Gas Analysis and Hemoximetry, Respiratory Care, 38:505-510, 1993

Tuesday, April 3, 2018

AIMS65 score

Q: All of the following are predictors of increased inpatient mortality in patients presenting with upper gastro-intestinal bleed (UGIB) except?

A) Albumin less than 3.0 g/dL 
B) INR higher than 2 
C) Mental status change
D) Systolic blood pressure less than 90 mmHg
E) 65 or older age 

Answer: B

Above question represents "AIMS65" score, which has been found to have an excellent accuracy for predicting hospital mortality for patients presenting with UGIB. The score was developed from the cohort of almost 62,000 patients. 

A = Albumin less than 3.0 g/dL 
I = INR higher than 1.5 
M = Mental status change 
S = Systolic blood pressure less than 90 mmHg 
65 = Age older



1. Saltzman JR, Tabak YP, Hyett BH, et al. A simple risk score accurately predicts in-hospital mortality, length of stay, and cost in acute upper GI bleeding. Gastrointest Endosc 2011; 74:1215. 

2. Hyett BH, Abougergi MS, Charpentier JP, et al. The AIMS65 score compared with the Glasgow-Blatchford score in predicting outcomes in upper GI bleeding. Gastrointest Endosc 2013; 77:551.

3. Tang Y, Shen J, Zhang F, et al. Scoring systems used to predict mortality in patients with acute upper gastrointestinal bleeding in the ED. Am J Emerg Med 2018; 36:27.

Monday, April 2, 2018

Transient Global Amnesia

Q: Transient Global Amnesia (TGA) is an integral part of? 

 A) Stroke
B) Post-seizure 
C) Metabolic encephalopathy
D) Delirium
E) None of the above

Answer: E

TGA is a very distinct clinical condition of a transient "antegrade amnesia" for which no specific etiology has been determined but the site of dysfunction is the medial aspect of the temporal lobe. Epidemiologically, it appears to be an age-related condition. Two distinct clinical features in most cases are 1) disorientation to place and time and 2) repetitive questioning about whereabouts.

Patients with TGA have no increased risk of Transient Ischemic Attacks (TIAs), stroke and death. The episode usually lasts for six hours and can be easily confused by clinicians.

No treatment is recommended as overall it is a benign condition. There is no restriction to driving either in isolated cases.


1. Quinette P, Guillery-Girard B, Dayan J, et al. What does transient global amnesia really mean? Review of the literature and thorough study of 142 cases. Brain 2006; 129:1640.

2. Miller JW, Petersen RC, Metter EJ, et al. Transient global amnesia: clinical characteristics and prognosis. Neurology 1987; 37:733.

3. Pantoni L, Bertini E, Lamassa M, et al. Clinical features, risk factors, and prognosis in transient global amnesia: a follow-up study. Eur J Neurol 2005; 12:350.

Sunday, April 1, 2018

Hunter's Algorithm - Serotonin Toxicity

Q: All of the following are parts of Serotonin Syndrome (SS) except?

A) Hyperthermia 

B) Ocular clonus
C) Deep tendon hyperreflexia 
D) Inducible muscle clonus 
E) Neuromuscular findings more pronounced in the upper extremities

Answer: E

SS is a clinical diagnosis. A wide range of clinical signs can be seen in SS including fluctuations in vital signs, hyperthermia, agitation, ocular clonus, muscle rigidity,  mydriasis, tremors, deep tendon hyperreflexia, inducible or spontaneous muscle clonus, dry mucous membranes, and diaphoresis. Neuromuscular findings are usually more pronounced in the lower extremities including bilateral Babinski signs.

Related: Hunter's Decision Rules (algorithm) for Diagnosis of Serotonin Toxicity at


Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005; 352:1112.