AAST-BCI

Q: Heart Injury Scale from American Association for the Surgery of Trauma (AAST) is divided into how many grades? (select one)

A) Two

B) Three

C) Four

D) Five

E) Six

Answer: E

The Heart Injury Scale from the American Association for the Surgery of Trauma (AAST) divides Blunt Cardiac Injury (BCI) into six grades. The main feature of each grade are

• I - minor ECG abnormality 
• II - heart block or ischemic changes without cardiac failure
• III - sustained or multifocal ventricular contractions
• IV - septal rupture, pulmonary or tricuspid incompetence, papillary muscle dysfunction, or distal coronary artery occlusion producing cardiac failure
• V - proximal coronary artery occlusion
• VI   - Penetrating wound producing >50% tissue loss of a chamber

Please refer to https://www.aast.org/resources-detail/injury-scoring-scale (Table 3) for details of scoring

#trauma

Reference:

Moore EE, Malangoni MA, Cogbill TH, et al. Organ injury scaling. IV: Thoracic vascular, lung, cardiac, and diaphragm. J Trauma 1994; 36:299.

Brugada and covid-19

Q: 44 years old male with known history of Brugada syndrome is admitted to ICU with COVID-19. What should be the first priority?

Answer: Try to keep him afebrile

Patients with Brugada syndrome very quickly develop ventricular arrhythmias when become febrile. This is particularly of high risk in patients with Brugada Type 1 pattern EKG or previous history of syncope.

#cardiology

References:

1. Roterberg G, El-Battrawy I, Veith M, Liebe V, Ansari U, Lang S, Zhou X, Akin I, Borggrefe M. Arrhythmic events in Brugada syndrome patients induced by fever. Ann Noninvasive Electrocardiol. 2020 May;25(3):e12723. doi: 10.1111/anec.12723. Epub 2019 Nov 20. PMID: 31746533; PMCID: PMC7358877.

2. Michowitz Y, et. al. Fever-related arrhythmic events in the multicenter Survey on Arrhythmic Events in Brugada Syndrome. Heart Rhythm. 2018 Sep;15(9):1394-1401. doi: 10.1016/j.hrthm.2018.04.007. Epub 2018 Apr 9. PMID: 29649615.

Sodium and GBS

Q: Which of the following is a poor prognostic sign in Guillain-Barre Syndrome (GBS)?

A) hyponatremia

B) hypernatremia

Answer: A

There are two related clinical conditions that may bear poor prognosis in GBS - dysautonomia, and syndrome of inappropriate antidiuretic hormone secretion (SIADH). Both conditions can lead to hyponatremia.

Dysautonomia results in ileus, blood pressure, heart rate variations, fever, urinary retention, and sudden death. Autonomic involvement may also cause SIAH.

#neurology

References:

1. Chakraborty T, Kramer CL, Wijdicks EFM, Rabinstein AA. Dysautonomia in Guillain-Barré Syndrome: Prevalence, Clinical Spectrum, and Outcomes. Neurocrit Care 2020; 32:113.

2. Zochodne DW. Autonomic involvement in Guillain-Barré syndrome: a review. Muscle Nerve 1994; 17:1145.

3. Anandan C, Khuder SA, Koffman BM. Prevalence of autonomic dysfunction in hospitalized patients with Guillain-Barré syndrome. Muscle Nerve 2017; 56:331.

US in pregnancy

Q: Ultrasound (US) should be used with caution in febrile pregnant patients?

A) True

B) False

Answer: A

Although in general US is considered safe in pregnancy, this statement comes with a few caveats. The harm from US is mostly in regards to temperature rise around the tissues. B and M-mode imagings have acoustic outputs without much harmful temperature rise, but spectral and color Doppler US equipment has greater time-averaged intensities and may produce biologically significant temperature rise. The use of fetal Doppler in the first trimester may have a potential effect on organogenesis. Spectral Doppler, color flow imaging, power imaging, and other Doppler ultrasound modalities should generally not be used unless absolutely necessary in the embryonic period at least up to 10 weeks of gestation. 

In this regard extra care is needed for a pregnant patient who is febrile.

#ob-gyn

#radiology

References:

1. American Institute of Ultrasound in Medicine. AIUM practice guideline for the performance of obstetric ultrasound examinations. J Ultrasound Med 2013; 32:1083.

2. Sheiner E, Shoham-Vardi I, Abramowicz JS. What do clinical users know regarding safety of ultrasound during pregnancy? J Ultrasound Med 2007; 26:319.

3. Salvesen K, Abramowicz J, Ter Haar G, et al. ISUOG statement on the safe use of Doppler for fetal ultrasound examination in the first 13 + 6 weeks of pregnancy (updated). Ultrasound Obstet Gynecol 2021; 57:1020.

4. Bhide A, Acharya G, Baschat A, et al. ISUOG Practice Guidelines (updated): use of Doppler velocimetry in obstetrics. Ultrasound Obstet Gynecol 2021; 58:331.

5. Bly S, Van den Hof MC, Diagnostic Imaging Committee, Society of Obstetricians and Gynaecologists of Canada. Obstetric ultrasound biological effects and safety. J Obstet Gynaecol Can 2005; 27:572.

6. Abramowicz JS. Fetal Doppler: how to keep it safe? Clin Obstet Gynecol 2010; 53:842.

Type 1 and 2 errors

Q: What is the difference between type 1 error and type 2 error?

Answer: In clinical trials, type 1 and type 2 errors present a great challenge to the investigators. This mostly occurs under the phenomenon called 'chance'. 

Random variations occur within the sample size of any study. 

• Type 1 (alpha error) - If random chance leads to a wrong conclusion that there is a positive or negative effect
• Type 2 (beta error) - If random chance leads to a wrong conclusion that there is no effect

#clinical-trials

Reference:

Akobeng AK. Understanding type I and type II errors, statistical power and sample size. Acta Paediatr. 2016 Jun;105(6):605-9. doi: 10.1111/apa.13384. Epub 2016 Mar 31. PMID: 26935977.

dialysis and hypercalcemia

Q: Dialysis can be used as a last resort in the treatment of refractory hypercalcemia?

A) True

B) False

Answer: A

Dialysis can be used as an effective therapy for refractory or emergent hypercalcemia, with little or no calcium in the dialysis fluid. Patients who may not be able to handle saline or intravenous (IV) resuscitation, or with severe malignancy-associated hypercalcemia can be a candidate. A nephrologist should be consulted to prescribe the dialysis solutions to avoid other metabolic derangements.

#electrolytes

#nephrology

References:

1. Basok AB, Rogachev B, Haviv YS, Vorobiov M. Treatment of extreme hypercalcaemia: the role of haemodialysis. BMJ Case Rep. 2018 Jun 4;2018:bcr2017223772. doi: 10.1136/bcr-2017-223772. PMID: 29866671; PMCID: PMC5990060.

2. Koo WS, Jeon DS, Ahn SJ, et al. Calcium-free hemodialysis for the management of hypercalcemia. Nephron 1996; 72:424.

Appendectomy in obese patients

Q; 48 years old morbidly obese patient is admitted to ICU with acute appendicitis. Laparoscopic appendectomy should be avoided?

A) True

B) False

Answer: B

Laparoscopic appendectomy is the recommended approach in obese patients with body mass index of >30 kg/m2. Evidence shows less postoperative wound infections/abscesses, shorter operative time and less hospital length of stay (LOS).

#surgical-critical-care

References:

1. Enochsson L, Hellberg A, Rudberg C, et al. Laparoscopic vs open appendectomy in overweight patients. Surg Endosc 2001; 15:387.

2. Mason RJ, Moazzez A, Moroney JR, Katkhouda N. Laparoscopic vs open appendectomy in obese patients: outcomes using the American College of Surgeons National Surgical Quality Improvement Program database. J Am Coll Surg 2012; 215:88.

3. Ciarrocchi A, Amicucci G. Laparoscopic versus open appendectomy in obese patients: A meta-analysis of prospective and retrospective studies. J Minim Access Surg 2014; 10:4.

alcoholism with acute myopathy

Q: 42 years old male with history of alcoholism is admitted to ICU with acute myopathy. Which muscles are more prone to get effected? (select one)

A) distal

B) proximal

Answer: B

Patients may develop acute myopathy during an alcoholic binge if superimposed with no eating. Symptoms include weakness, pain, tenderness, and swelling of affected muscles. Proximal muscles tend to be more effected. For unknown reason, males get effected with high proportion. In its severe form it involves smooth and cardiac muscles leading to dysphagia, arrhythmias and congestive heart failure. As expected laboratory findings involve elevation of serum creatine kinase (CK), myoglobinuria, and electrolyte disturbances. Electromyogram shows fibrillations and myopathic changes, and biopsy usually shows muscle fiber necrosis.

Treatment is supportive.

#ETOH

#musculo-skeletal

References:

1. Martin F, Ward K, Slavin G, et al. Alcoholic skeletal myopathy, a clinical and pathological study. Q J Med 1985; 55:233.

2. Rubin E. Alcoholic myopathy in heart and skeletal muscle. N Engl J Med 1979; 301:28.

3. Weber LD, Nashel DJ, Mellow MH. Pharyngeal dysphagia in alcoholic myopathy. Ann Intern Med 1981; 95:189.

NPH and gait

Q: 57 years old female is admitted to ICU post-shunt for Normal Pressure Hydrocephalous (NPH). Patient gait abnormality is unlikely to improve despite good shunt function?

A) True

B) False

Answer: B

Patients with NPH get very distressed with their gait. It is popularly known as "glue-footed" gait. Other names are magnetic gait, gait apraxia, and frontal ataxia. This gait is characterized by small steps, and with a wide base. This makes the turning difficult. They have to take small steps to turn around. Fall is the biggest risk. "Pull test" can be performed to establish postural instability. Fortunately, gait abnormality is most responsive to shunting.

#neourology

#neurosurgery

References:

1. Sudarsky L, Simon S. Gait disorder in late-life hydrocephalus. Arch Neurol 1987; 44:263.

2. Stolze H, Kuhtz-Buschbeck JP, Drücke H, et al. Comparative analysis of the gait disorder of normal pressure hydrocephalus and Parkinson's disease. J Neurol Neurosurg Psychiatry 2001; 70:289.

Kehr's sign

Q: 24 years old male is admitted to ICU after Motor Vehicle Accident (MVA). Trauma surgeon's note reads: "Positive Kehr's sign": What is Kehr's sign?

Answer: 

Kehr's sign is mostly pertinent in splenic rupture. Patient complains of left upper abdominal, left chest wall, and/or left shoulder pain that worsens with inspiration. The blood adjacent to the left hemidiaphragm irritates the phrenic nerve and exacerbates with inspiration. This can also be demonstrated by raising the legs while patient is in a supine position. 

Although known for many decades (see reference #1), and easy to perform, it frequently gets neglected during the initial evaluation.

#physical-exam

#trauma

#GI

Reference:

Lowenfels AB. Kehr's sign--a neglected aid in rupture of the spleen. N Engl J Med. 1966 May 5;274(18):1019. doi: 10.1056/NEJM196605052741810. PMID: 5909736.

Rastogi V, Singh D, Tekiner H, Ye F, Mazza JJ, Yale SH. Abdominal Physical Signs of Inspection and Medical Eponyms. Clin Med Res. 2019;17(3-4):115-126. doi:10.3121/cmr.2019.1420

DGI

Q; 35 years old male is admitted to ICU with sepsis and disseminated gonococcal infection (DGI) is suspected. Patient is found to have purulent polyarthritis. Polyarthritis in DGI is usually? (select one)

A) symmetric

B) asymmetric

Answer: B

Although with recent advances, DGI is not frequently encountered, few features of DGI are unique and may help to establish differential diagnoses. Some of the characteristics of DGI are:

• It is usually of abrupt onset
• monoarthritis is relatively more common
• if there is polyarthritis, it's usually asymmetric. 
• mostly afebrile
• urethritis is unlikely to precede DGI 

Although a "classic triad" of tenosynovitis, dermatitis, and polyarthralgia is described but is not always present. 

#ID

#STDs

References:

1. Birrell JM, Gunathilake M, Singleton S, Williams S, Krause V. Characteristics and Impact of Disseminated Gonococcal Infection in the "Top End" of Australia. Am J Trop Med Hyg. 2019 Oct;101(4):753-760. doi: 10.4269/ajtmh.19-0288. PMID: 31392956; PMCID: PMC6779203.

2. Bardin T. Gonococcal arthritis. Best Pract Res Clin Rheumatol 2003; 17:201.

3. Rice PA. Gonococcal arthritis (disseminated gonococcal infection). Infect Dis Clin North Am 2005; 19:853.

PFCs

Q: How a pancreatic pseudocyst and walled-off pancreatic necrosis can be distinguised on CT scan?

Answer:  Although both pancreatic pseudocyst and walled-off pancreatic necrosis can have a well-defined wall and absence of internal septa within the cavity, the following features can distuingish both entities.

Pancreatic pseudocyst will have the following characteristics:

• Round or oval fluid collection
• The fluid collection is usually extra-pancreatic
• Homogenous fluid density (no non-liquid components)

Walled-off pancreatic necrosis can be differentiated by

• Heterogenous fluid collection with liquid and non-liquid density
• Location can be intra-pancreatic and/or extra-pancreatic

#surgical-critical-care

#GI

Reference:

Banks PA, Bollen TL, Dervenis C, et al. Classification of acute pancreatitis--2012: revision of the Atlanta classification and definitions by international consensus. Gut 2013; 62:102.

FFS-EGPA

Q: Presence of ear, nose, and throat (ENT) symptoms predict poor outcome in Eosinophilic Granulomatosis with PolyAngiitis (EGPA) (Churg-Strauss)?

A) True

B) False

Answer: B

Sounds strange but the presence of ENT symptoms predicts a better prognosis in EGPA, also known as Churg-Strauss syndrome. 

EGPA is an antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis of the small and medium-sized arteries. The severity of the disease can be calculated by various scores but one of the commonly used score in clinical setting is "five-factor score" (FFS). The score was initially proposed in 1996 and was revised in 2011. It includes,

• Age >65
• Cardiac insufficiency
• Gastrointestinal (GI) involvement
• Renal insufficiency (stabilized peak plasma creatinine concentration >1.7 mg/dL [150 micromol/L])
• Absence of ENT manifestations 

#rheumatology

References:

Guillevin L, Pagnoux C, Seror R, et al. The Five-Factor Score revisited: assessment of prognoses of systemic necrotizing vasculitides based on the French Vasculitis Study Group (FVSG) cohort. Medicine (Baltimore) 2011; 90:19.

Gayraud M, Guillevin L, le Toumelin P, et al. Long-term followup of polyarteritis nodosa, microscopic polyangiitis, and Churg-Strauss syndrome: analysis of four prospective trials including 278 patients. Arthritis Rheum 2001; 44:666.

Moosig F, Bremer JP, Hellmich B, et al. A vasculitis centre based management strategy leads to improved outcome in eosinophilic granulomatosis and polyangiitis (Churg-Strauss, EGPA): monocentric experiences in 150 patients. Ann Rheum Dis 2013; 72:1011.

ASA toxicity and HD

Q: Salicylate-induced pulmonary edema is  ____________ indication for hemodialysis? (select one)

A) absolute

B) relative

Answer: A

Salicylate overdose is well known to cause noncardiogenic pulmonary edema and acute lung injury (ALI), particularly in chronic users. 

Salicylate-induced pulmonary edema is an absolute indication of hemodialysis (HD). The mainstay of treatments for salicylate toxicity is sodium bicarbonate and intravenous fluid resuscitation, which can further worsen the pulmonary edema leading to intubation and risk of cardio-pulmonary arrest.

#toxicology

#pulmonary

References:

1. Leatherman JW, Schmitz PG. Fever, hyperdynamic shock, and multiple-system organ failure. A pseudo-sepsis syndrome associated with chronic salicylate intoxication. Chest 1991; 100:1391. 

2. Fertel BS, Nelson LS, Goldfarb DS. The underutilization of hemodialysis in patients with salicylate poisoning. Kidney Int. 2009 Jun;75(12):1349-1353. doi: 10.1038/ki.2008.443. Epub 2008 Aug 20. PMID: 18716600. 

3. Minns AB, Cantrell FL, Clark RF. Death due to acute salicylate intoxication despite dialysis. J Emerg Med. 2011 May;40(5):515-7. doi: 10.1016/j.jemermed.2010.02.015. Epub 2010 Mar 29. PMID: 20347249.

HELLP

Q: HELLP syndrome can develop postpartum?

A) True

B) False

Answer: A

Although, by definition, HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets) is a disease of pregnancy but can occur for up to six weeks postpartum. 

This phenomenon is hard to explain as the delivery of the baby and placenta is considered to cure the disease.

#ob-gyn

Reference:

Pop-Trajković S, Antić V, Kopitović V, Popović J, Trenkić M, Vacić N. Postpartum HELLP syndrome--the case of lost battle. Ups J Med Sci. 2013;118(1):51-53. doi:10.3109/03009734.2012.725431

saddled PE and hemodynamic

Q: Saddle Pulmonary Embolism (PE) is usually associated with hemodynamic instability?

A) True

B) False

Answer: B

Although saddle PE is expected to cause hemodynamic instability, less than one-fourth of patients experience this. Moreover, mortality from saddle PE is only 5 percent if a patient receives care at time. 

The total frequency of saddled PE is only around 5 percent.

#pulmonary

References:

1. Ryu JH, Pellikka PA, Froehling DA, et al. Saddle pulmonary embolism diagnosed by CT angiography: frequency, clinical features and outcome. Respir Med 2007; 101:1537. 

2. Sardi A, Gluskin J, Guttentag A, et al. Saddle pulmonary embolism: is it as bad as it looks? A community hospital experience. Crit Care Med 2011; 39:2413.

TPA in CVA

Q: The benefit of alteplase in reperfusion therapy for acute ischemic stroke is similar regardless of patient age or stroke severity?

A) True

B) False

Answer: A

In contrast to conventional belief, the benefit of alteplase in reperfusion therapy for acute ischemic stroke is similar regardless of patient age or stroke severity. This came from a huge meta-analysis combining NINDS, ATLANTIS, ECASS, EPITHET, and IST-3 trials (6756 patients). Moreover, the risk of fatal intracranial hemorrhage stays similar regardless of age, stroke severity, or treatment delay. 

Although as expected the Odd Ratio (OD) of symptomatic intracranial hemorrhage stays high when compared to control, the number needed to harm (NNH) for one additional patient to have symptomatic intracranial hemorrhage is found to be 18. 

#neurosurgery

#neurology

References:

1. Emberson J, Lees KR, Lyden P, et al. Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials. Lancet 2014; 384:1929.

2. Lees KR, Bluhmki E, von Kummer R, et al. Time to treatment with intravenous alteplase and outcome in stroke: an updated pooled analysis of ECASS, ATLANTIS, NINDS, and EPITHET trials. Lancet 2010; 375:1695.

3. Emberson J, Lees KR, Lyden P, et al. Effect of treatment delay, age, and stroke severity on the effects of intravenous thrombolysis with alteplase for acute ischaemic stroke: a meta-analysis of individual patient data from randomised trials. Lancet 2014; 384:1929.

PAWSS

Q: 54 years old male with previous history of Delirium Tremens (DT) is admitted to ICU with unknown amount of alcohol ingestion. At what level of "PAWSS" score the chances of clinically significant alcohol withdrawal becomes significant? (select one)

A) ≥ 4 

B) ≥ 8

Answer: A

Prediction of Alcohol Withdrawal Severity Scale (PAWSS) is considered as one of the reliable screening tool to predict clinically significant alcohol withdrawal symptoms. After the first triage question, scale consists of 10 questions. At score of ≥4 the chances of moderate to severe withdrawal becomes imminent, and can be averted with prophylaxis.

Score can be accessed at https://www.mdcalc.com/prediction-alcohol-withdrawal-severity-scale

#toxicology

Reference: 

Maldonado JR, Sher Y, Ashouri JF, Hills-Evans K, Swendsen H, Lolak S, Miller AC. The "Prediction of Alcohol Withdrawal Severity Scale" (PAWSS): systematic literature review and pilot study of a new scale for the prediction of complicated alcohol withdrawal syndrome. Alcohol. 2014 Jun;48(4):375-90. doi: 10.1016/j.alcohol.2014.01.004. Epub 2014 Feb 19. PMID: 24657098.

Procalcitonin in renal insuff.

Q: Procalcitonin clears with dialysis?

A) Yes

B) No

Answer: A

Procalcitonin can't be trusted with full accuracy in renal insufficiency. This is for two major reasons. On one hand, the baseline procalcitonin is higher in these patients and on the other hand it gets cleared by both continuous renal replacement therapy (CRRT) and hemodialysis (HD). 

It may be more worthwhile to follow the trend in renal insufficiency than relying on a single value.

#ID

#nephrology

#laboratory-science

References:

Grace E, Turner RM. Use of procalcitonin in patients with various degrees of chronic kidney disease including renal replacement therapy. Clin Infect Dis 2014; 59:1761.

Takahashi G, Shibata S, Fukui Y, et al. Diagnostic accuracy of procalcitonin and presepsin for infectious disease in patients with acute kidney injury. Diagn Microbiol Infect Dis 2016; 86:205.

actinomycosis

Q: 58 years old male with history of Crohn's disease is referred from outside hospital for higher level of care for abdominal actinomycosis. Which of the following antibiotics is the drug of choice? (select one)

  

A) Aminoglycosides

B) Metronidazole

C) Trimethoprim-sulfamethoxazole

D) Antifungal 

E) High-dose penicillin

  

  

Answer: E

  

High-dose penicillin (choice E) is the drug of choice in severe, invasive or extensive actinomycosis. It requires prolonged intravenous (IV) infusion. Once clinical situation improves or in mild cases, oral form can be used. These patients frequently require surgical interventions. In patients with penicillin allergy ceftriaxone, doxycycline, macrolides or carbapenems can be used.

 

It is important to know that aminoglycosides, metronidazole, aztreonam, trimethoprim-sulfamethoxazole, nafcillin, oxacillin, cephalexin, ceftazidime, and/or antifungal drugs have no tole in the treatment of actinomycosis. Clindamycin and fluoroquinolones have been described but lacks data in this regard.

#ID

References:

1. Valour F, Sénéchal A, Dupieux C, Karsenty J, Lustig S, Breton P, Gleizal A, Boussel L, Laurent F, Braun E, Chidiac C, Ader F, Ferry T. Actinomycosis: etiology, clinical features, diagnosis, treatment, and management. Infect Drug Resist. 2014 Jul 5;7:183-97. doi: 10.2147/IDR.S39601. PMID: 25045274; PMCID: PMC4094581.

2. Boyanova L, Kolarov R, Mateva L, Markovska R, Mitov I. Actinomycosis: a frequently forgotten disease. Future Microbiol. 2015;10(4):613-28. doi: 10.2217/fmb.14.130. PMID: 25865197.

3. LeCorn DW, Vertucci FJ, Rojas MF, et al. In vitro activity of amoxicillin, clindamycin, doxycycline, metronidazole, and moxifloxacin against oral Actinomyces. J Endod 2007; 33:557.

Angiography in Lower GIB

Q: In the absence of prior localization, which of the following vessel is evaluated first in angiography for lower Gastrointestinal Bleed (GIB)? (select one)

A) superior mesenteric artery 

B) inferior mesenteric artery

Answer: A

In the real world, clinicians usually have some idea of area involved in GIB either via nuclear scan ot CT-Angiography (CTA). In case of acute severe GIB where patient is taken directly for angiography due to it's advantage of simultaneous embolization of involved vessel, superior mesenteric artery is generally evaluated first followed by the inferior mesenteric and celiac arteries. In contrast to conventional expectations, success rate runs anywhere from 25 to 70 percent.

#procedure

#radiology

References:

1. Browder W, Cerise EJ, Litwin MS. Impact of emergency angiography in massive lower gastrointestinal bleeding. Ann Surg 1986; 204:530.

2.  Udén P, Jiborn H, Jonsson K. Influence of selective mesenteric arteriography on the outcome of emergency surgery for massive, lower gastrointestinal hemorrhage. A 15-year experience. Dis Colon Rectum 1986; 29:561. 

3. Speir EJ, Ermentrout RM, Martin JG. Management of Acute Lower Gastrointestinal Bleeding. Tech Vasc Interv Radiol. 2017 Dec;20(4):258-262. doi: 10.1053/j.tvir.2017.10.005. Epub 2017 Oct 9. PMID: 29224658.

Allopurinol and angina

Q: Allopurinol also has an anti-anginal effect?

A) Yes

B) No

Answer: A

Allopurinol when compared with placebo, showed to increase the median time to ST depression as well as median total exercise time. The anti-ischemic effect of allopurinol is probably due to endothelium-dependent vasodilation and significant abolishing of oxidative stress. The effective dose is 600 mg per day.

Said that, at this point this effect is more of an academic interest. A large trial is needed before allopurinol can be prescribed for its anti-anginal effect.

#pharmacology

#cardiology

References:

1. Noman A, Ang DS, Ogston S, et al. Effect of high-dose allopurinol on exercise in patients with chronic stable angina: a randomised, placebo controlled crossover trial. Lancet 2010; 375:2161. 

2. Rajendra NS, Ireland S, George J, et al. Mechanistic insights into the therapeutic use of high-dose allopurinol in angina pectoris. J Am Coll Cardiol 2011; 58:820.

supine and sitting spirometry to evaluate diaphragmatic weakness

Q: How supine and sitting spirometry helps in evaluating diaphragmatic weakness?

Answer: Measuring Vital Capacity (VC) supine followed by in sitting position can give a quick idea regarding the strength of the diaphragm

• If Vital Capacity (VC) decreased by more than 10 percent, it suggests diaphragmatic weakness. 
• If VC decreased by 15 to 25 percent, it suggests unilateral diaphragmatic paralysis. 
• And, if VC decreased by half bilateral diaphragmatic paralysis is highly suspected.

#pulmonary

References;

1. Kokatnur L, Rudrappa M. Diaphragmatic Palsy. Diseases. 2018;6(1):16. Published 2018 Feb 13. doi:10.3390/diseases6010016 

2. Lechtzin N, Wiener CM, Shade DM, Clawson L, Diette GB. Spirometry in the supine position improves the detection of diaphragmatic weakness in patients with amyotrophic lateral sclerosis. Chest. 2002 Feb;121(2):436-42. doi: 10.1378/chest.121.2.436. PMID: 11834654.

capacity, cognition and function

Q: Describe the difference between capacity, cognition, and function?

Answer: In ethics, capacity frequently becomes a significant value when it needs to be determined if a patient is capable of making decisions. Capacity is a distinct value from cognition and function. 

 

Cognition describes the various coordinated (physiological) functions of the brain. 

 

Function is related to different coordinated (anatomical) activities. Capacity is more of a supra-tentorial ability to understand the benefits and risks of a particular decision given the information provided.

#ethics

#psychiatry

Reference:

Jason Karlawish, Steven T DeKosky, FANAMario F Mendez - Assessment of decision-making capacity in adults Assessment of decision-making capacity in adults 

https://www.uptodate.com/contents/assessment-of-decision-making-capacity-in-adults - last updated: Sep 16, 2021.

Sodium nitroprusside induced cyanide poisoning

Q: If a patient requires sodium nitroprusside infusion, what are the few precautions which may prevent cyanide poisoning?

Answer: Patients who require higher and prolonged infusions of Sodium nitroprusside, and patients with renal insufficiency are prone to cyanide poisoning. Over the years, the use of sodium nitroprusside is decreased in the United States due to these concerns. 

Applying silver foil on IV tubing prevents light from decomposing the nitroprusside molecule. Other preventive measures include not to exceed the infusion beyond 2 mcg/kg per minute, and adding sodium thiosulfate to the nitroprusside solution.

#pharmacology

#toxicology

References:

1. Bryson, PD. Comprehensive Review in Toxicology for Emergency Clinicians, 3rd, Taylor and Francis, Denver 1996. p.352. 

2. The New York Poision Control Center. An Intensive Review Course in Clinical Toxicology, 2005. p.141.

frequency of fungal endocarditis

Q: Arterial embolization from fungal endocarditis is more common than bacterial endocarditis.

A) True

B) False

Answer: A

Fungal endocarditis tends to have a higher incidence of arterial embolization than bacterial endocarditis. The most probable reason is the larger size of the vegetations. These embolizations tends to go and seed in brain, limbs and GI tract. Stigmatas of bacterial endocarditis can be present such as Osler nodes, Roth spots, and Janeway lesions.  

#ID

#cardiology

References:

1. Ellis ME, Al-Abdely H, Sandridge A, et al. Fungal endocarditis: evidence in the world literature, 1965-1995. Clin Infect Dis 2001; 32:50.

2. Rubinstein E, Noriega ER, Simberkoff MS, et al. Fungal endocarditis: analysis of 24 cases and review of the literature. Medicine (Baltimore) 1975; 54:331. 

3. Yuan SM. Fungal Endocarditis. Braz J Cardiovasc Surg. 2016 May-Jun;31(3):252-255. doi: 10.5935/1678-9741.20160026. PMID: 27737409; PMCID: PMC5062704. 

4. Pasha AK, Lee JZ, Low SW, Desai H, Lee KS, Al Mohajer M. Fungal Endocarditis: Update on Diagnosis and Management. Am J Med. 2016 Oct;129(10):1037-43. doi: 10.1016/j.amjmed.2016.05.012. Epub 2016 Jun 4. PMID: 27267285.

Type B AD - risks

Q: Bicuspid aortic valve is protective of type B aortic dissection in young patients? 

A) True

B) False

Answer: B

The objective of this question is to highlight the risk factors of type B aortic dissection (AD) in younger patients. In general type B aortic dissection occurs in older patients but some risk factors can make it a disease of relatively younger patients. Few of the major risk factors are:

• Severe acute hypertension 
• High-intensity exercise
• Drug abuse (particularly cocaine) 
• Connective tissue disorder (most famous - Marfan syndrome)
• Bicuspid aortic valve
• Previous aortic surgery
• Aortic coarctation
• Turner syndrome
• Inflammatory vasculitis (giant cell arteritis, Takayasu arteritis)
• Blunt aortic trauma
• Pregnancy and delivery

#cardio-thoracic

#vascular

References:

1. Luebke T, Brunkwall J. Type B Aortic Dissection: A Review of Prognostic Factors and Meta-analysis of Treatment Options. Aorta (Stamford). 2014 Dec 1;2(6):265-78. doi: 10.12945/j.aorta.2014.14-040. PMID: 26798745; PMCID: PMC4682679.

2. Shalhub S, Roman MJ, Eagle KA, LeMaire SA, Zhang Q, Evangelista A, Milewicz DM; Genetically Triggered Thoracic Aortic Aneurysms and Cardiovascular Conditions (GenTAC) Consortium. Type B Aortic Dissection in Young Individuals With Confirmed and Presumed Heritable Thoracic Aortic Disease. Ann Thorac Surg. 2020 Feb;109(2):534-540. doi: 10.1016/j.athoracsur.2019.07.004. Epub 2019 Jul 31. PMID: 31376376.

exam in PAD

Q: 72 years old male with long standing history of smoking presented with acute pain in upper calf area. The suspected artery is? ( select one)

A) superficial femoral artery 

B) popliteal artery

Answer: A

The objective of this question is to highlight the importance of history taking and physical exam in peripheral vascular disease. Patient symptoms and area of pain/claudication provide enough clue of probable involved vessels. Few examples are:

• buttock and hip claudication – aortoiliac disease  
• thigh claudication – common femoral artery
• upper 2/3rd calf claudication – superficial femoral artery 
• lower third of the calf - popliteal disease
• foot claudication – tibial and peroneal vessels

70 years ago when diagnostic imaging were not available, a physical exam determined the diseased vessel.  

#vascular

#physical-exam

#surgical-critical-care

References:

1. Leriche R, Morel A. The Syndrome of Thrombotic Obliteration of the Aortic Bifurcation. Ann Surg 1948; 127:193.

2. Armstrong DW, Tobin C, Matangi MF. The accuracy of the physical examination for the detection of lower extremity peripheral arterial disease. Can J Cardiol. 2010 Dec;26(10):e346-50. doi: 10.1016/s0828-282x(10)70467-0. PMID: 21165366; PMCID: PMC3006105.

3. Rajamanickam A, Krishnan P. History and Physical Examination in Diagnosis of Peripheral Artery Disease. Interv Cardiol Clin. 2014 Oct;3(4):461-467. doi: 10.1016/j.iccl.2014.06.007. Epub 2014 Oct 2. PMID: 28582072.

LFT in non-liver diseases

Q: In Rhabdomyolysis which of the aminotransferase tends to be higher than the other?

A) aspartate aminotransferase (AST) 

B) alanine aminotransferase (ALT) 

Answer: A

It is less appreciated that liver enzymes (LFT) are simultaneously elevated in rhabdomyolysis, and can easily be attributed to liver pathology. Elevations in LFT can be apparent even with Creatine Kinase (CK) at 1000 units/L. 

AST is usually elevated more than ALT. This clinical knowledge may help later in the course where the decline in AST (more than ALT) correlates with the resolution of rhabdomyolysis.

AST and ALT are widely found in skeletal and myocardial cells besides hepatic cells. Elevation can also be seen after hemolysis.

#lab-medicine

References:

1. Nathwani RA, Pais S, Reynolds TB, Kaplowitz N. Serum alanine aminotransferase in skeletal muscle diseases. Hepatology 2005; 41:380.

2. Yin LK, Tong KS. Elevated Alt and Ast in an Asymptomatic Person: What the primary care doctor should do?. Malays Fam Physician. 2009;4(2-3):98-99. Published 2009 Aug 31.

3. Malakouti M, Kataria A, Ali SK, Schenker S. Elevated Liver Enzymes in Asymptomatic Patients - What Should I Do?. J Clin Transl Hepatol. 2017;5(4):394-403. doi:10.14218/JCTH.2017.00027

Pulse-ox and dark skin

Q: Pulse oximetry readings usually ____________ the oxygen saturation in patients with darker skin? (select one)

A) overestimates

B) underestimates

Answer: A

Any kind of skin pigmentation including hyperbilirubinemia can falsely overestimate the pulse-ox reading. This may cause "hidden" hypoxemia. This may not be of concern in usual circumstances but given the recent COVID pandemic where clinicians are fighting for every single percent increase in pulse-ox level, this may be of bedside importance. This discrepancy can be up to 4 percent or more.  This“hidden” hypoxemia may lead to higher organ dysfunction scores and in-hospital mortality.

#procedures

#oxygenation

References:

1. Bickler PE, Feiner JR, Severinghaus JW. Effects of skin pigmentation on pulse oximeter accuracy at low saturation. Anesthesiology 2005; 102:715.

2. Sjoding MW, Dickson RP, Iwashyna TJ, et al. Racial Bias in Pulse Oximetry Measurement. N Engl J Med 2020; 383:2477.

3. Interim Clinical Guidance for Management of Patients with Confirmed Coronavirus Disease (COVID-19), February 16, 2021. https://www.cdc.gov/coronavirus/2019-ncov/hcp/clinical-guidance-management-patients.html (Accessed on April 12, 2022).

4. Wong AI, Charpignon M, Kim H, et al. Analysis of Discrepancies Between Pulse Oximetry and Arterial Oxygen Saturation Measurements by Race and Ethnicity and Association With Organ Dysfunction and Mortality. JAMA Netw Open 2021; 4:e2131674.