Urea and Na

Q: Oral Urea tablets can be used in the treatment of? - select one

A) Hypernatremia

B) Hyponatremia

Answer: B

Although not widely used because of other modalities for treating hyponatremia, oral urea is one option for lowering sodium concentration. It is particularly useful in patients who require long-term treatment with Syndrome of Inappropriate Antidiuretic Hormone secretion (SIADH). It is popularly known as 'poor man's Vaptan.' It has shown its efficacy in acute cases also, such as on Intracranial Pressure (ICP) in Patients With Acute Brain Injury and Hyponatremia (reference# 4)

Urea is available as oral packets in the USA and can also be given via a nasogastric tube (NGT). The mechanism of action is via increasing the excretion of electrolyte-free water. The usual maintenance dose is 15 to 30 g/day.

#electrolytes

References:

1. Spasovski G, Vanholder R, Allolio B, et al. Clinical practice guideline on diagnosis and treatment of hyponatraemia. Nephrol Dial Transplant 2014; 29 Suppl 2:i1.

2. Decaux G, Andres C, Gankam Kengne F, Soupart A. Treatment of euvolemic hyponatremia in the intensive care unit by urea. Crit Care 2010; 14:R184.

3. Soupart A, Coffernils M, Couturier B, et al. Efficacy and tolerance of urea compared with vaptans for long-term treatment of patients with SIADH. Clin J Am Soc Nephrol 2012; 7:742.

4. Annoni F, Fontana V, Brimioulle S, et al. Early Effects of Enteral Urea on Intracranial Pressure in Patients With Acute Brain Injury and Hyponatremia. J Neurosurg Anesthesiol 2016.

 

Clozapine and tobacco

Q: A 64-year-old male with only a past history of depression and smoking is admitted to the hospital for severe community-acquired pneumonia (CAP). His only home medication is clozapine. His dose for clozapine should be? - select one

A) decreased

B) increased

Answer: A

Clozapine has a complex relationship with smoking. Smokers require almost a twofold increase in dose. Once they are stable on a higher-than-usual dose, it needs to be tapered down when in a nonsmoking environment.

Another important aspect of chronic clozapine use is the risk of agranulocytosis and its strong anticholinergic, sedative, cardiac, and hypotensive properties, so any agents with these characteristics should be used with care. 

#pharmacology

#psychiatry

References:

1. Tsuda Y, Saruwatari J, Yasui-Furukori N. Meta-analysis: the effects of smoking on the disposition of two commonly used antipsychotic agents, olanzapine and clozapine. BMJ Open 2014; 4:e004216.

2. McEvoy JP, Freudenreich O, Wilson WH. Smoking and therapeutic response to clozapine in patients with schizophrenia. Biol Psychiatry. 1999 Jul 1;46(1):125-9. doi: 10.1016/s0006-3223(98)00377-1. PMID: 10394482.

3. Zeng L, Lv H, Li J, Xue R, Liu X, Zhou C, Yu H. Cigarette smoking, coffee consumption, alcohol intake, and clozapine metabolism: A Mendelian randomization study. Front Psychiatry. 2022 Sep 29;13:1002235. doi: 10.3389/fpsyt.2022.1002235. PMID: 36245885; PMCID: PMC9559606.

importance of paracentesis in SBP

Q: What's the importance of paracentesis in spontaneous bacterial peritonitis (SBP)?

Answer: Determination of mortality

As famously said for lungs: "the sun should never set on a parapneumonic effusion, " similarly, it is true for abdominal paracentesis in SBP, as mortality increases by 3.3 percent/hour of delay in performing a paracentesis in patients with SBP.

Overall, hospitalized patients with SBP who received delayed paracentesis (DP) had a 2.7-fold increased risk of mortality, adjusting for MELD score and renal dysfunction. Diagnostic paracentesis performed less than 12 hours from hospitalization in patients with cirrhosis and ascites has improved short-term survival.  

#procedures

References:

1. Kim JJ, Tsukamoto MM, Mathur AK, et al. Delayed paracentesis is associated with increased in-hospital mortality in patients with spontaneous bacterial peritonitis. Am J Gastroenterol 2014; 109:1436.

2. Sahn SA, Light RW. The sun should never set on a parapneumonic effusion. Chest. 1989 May;95(5):945-7. doi: 10.1378/chest.95.5.945. PMID: 2707086.

3. Harvey JJ, Prentice R, George J. Diagnostic and therapeutic abdominal paracentesis. Med J Aust. 2023 Jan 16;218(1):18-21. doi: 10.5694/mja2.51795. Epub 2022 Nov 30. PMID: 36450339; PMCID: PMC10099762.

BAT

Q: Which of the following has the highest likelihood ratio (LR) of Blunt Abdominal Trauma, popularly known as BAT? - select one

A) Abdominal distension 

B) Abdominal guarding

C) Hypotension  

D) Rebound tenderness 

E) Seatbelt sign

Answer: E

Of note, the most important pearl to remember during trauma evaluation of the abdomen is: "The absence of abdominal pain or tenderness does not rule out significant intra-abdominal injury."

A history and physical exam should be performed in detail. Interestingly, the seatbelt sign has the highest LR of probable underlying BAT. 

Seat Belt sign is followed by rebound tenderness, and in frequency down with hypotension, and abdominal distension. Abdominal guarding has the lowest LR in the above question for BAT.

Another important pearl to remember is that "the negative LR for the above signs, either alone or in combination, is low, which means that the absence of either sign does not exclude injury."

                                                     

Concomitant femur fracture can significantly distract the clinician from BAT, particularly in pedestrian trauma.

#trauma

References:

1. Nishijima DK, Simel DL, Wisner DH, Holmes JF. Does this adult patient have a blunt intra-abdominal injury? JAMA 2012; 307:1517.

2. Shreffler J, Smiley A, Schultz M, et al. Patients with Abrasion or Ecchymosis Seat Belt Sign Have High Risk for Abdominal Injury, but Initial Computed Tomography is 100% Sensitive. J Emerg Med 2020; 59:491.

3. Pourmand A, Terrebonne E, Shapovalov V, et al. Prevalence of intra-abdominal injury among patients with seatbelt signs, a systematic review and meta-analysis. Am J Emerg Med 2024; 76:199.

4. Agrawal A, Inamadar PI, Subrahmanyam BV. Seat belt sign and its significance. J Family Med Prim Care. 2013 Jul;2(3):288-90. doi: 10.4103/2249-4863.120769. PMID: 24479100; PMCID: PMC3902689.

cola colored urine

Q: What could be the underlying renal pathophysiology in cola or tea colored urine?

Answer: Possible glomerular bleeding

An astute physician can quickly differentiate glomerular and nonglomerular bleeding at first sight at the bedside.

Cola or tea-colored or dark brown urine may indicate glomerular bleeding, in which prolonged transit time through the nephron in an acidic urine environment can result in the formation of methemoglobin, giving the urine a smoky brown, tea, or cola color.

Obviously, this is a first glance bedside observation at the bedside. Urine can still appear red or pink in glomerular bleeding if urine is not acidic, or transit time is too fast, but by default, as a rule of thumb, in gross hematuria -

• nonglomerular bleeding appears red or pink, and
• glomerular bleeding appears dark brown (cola colored)

Other caveats are false colorations due to dye, food, drugs, or underlying non-renal pathophysiologies such as rhabdomyolysis or hyperbilirubinemia.

#nephrology

References:

1. Stark A, Kanduri SR, Ramanand A, Rosenbloom S, Varghese V, Chalmers DR, Velez SA, Gonzalez-Fuentes C, Wickman TJ, Mohamed M, Shueib A, Zarm A, Lukitsch I, Velasco-Gonzalez C, Seltzer JR, Velez JCQ. Glomerular Hematuria for the Diagnosis of Glomerulonephritis. Glomerular Dis. 2025 Apr 10;5(1):206-218. doi: 10.1159/000545051. PMID: 40406196; PMCID: PMC12097761.

2. Rose BD. Pathophysiology of Renal Disease, 2nd ed, McGraw-Hill, New York 1987. p.10.

3. Hamadah AM, Gharaibeh K, Mara KC, Thompson KA, Lieske JC, Said S, Nasr SH, Leung N. Urinalysis for the diagnosis of glomerulonephritis: role of dysmorphic red blood cells. Nephrol Dial Transplant. 2018 Aug 1;33(8):1397-1403. doi: 10.1093/ndt/gfx274. PMID: 29156008.

Anbx in Ebola

Q: Patients with Ebola virus should be covered at least for? - select one

A) Gram-negative pathogens

B) Gram-positive pathogens

Answer: A

Prevention and isolation are foremost in the Ebola outbreak, and in case of infection, supportive treatment is the mainstay.

Two antibody-based therapies that have shown effectiveness for the Ebola virus.

1. Atoltivimab, maftivimab, and odesivimab (REGN-EB3) – It's a triple-monoclonal antibody (mAb) product. This combination of three mAbs targets three nonoverlapping epitopes on the Ebola virus surface glycoprotein, providing potent virus neutralization.

2. Ansuvimab (mAb114) – This mAb was originally isolated from a survivor of Ebola virus disease and found to neutralize the virus.

Although critical care patients should be covered with broad-spectrum antibiotics, gram-negative pathogens are more common in Ebola patients and should be covered. Said that empiric gram-positive therapy should be added as hospital-acquired pneumonia or CLABSI (Central Line Associated Blood Stream Infections) can have low thresholds to occur. 

#ID

References:

1. Kreuels B, Wichmann D, Emmerich P, et al. A case of severe Ebola virus infection complicated by gram-negative septicemia. N Engl J Med 2014; 371:2394.

2. Misasi J, Sullivan NJ. Immunotherapeutic strategies to target vulnerabilities in the Ebolavirus glycoprotein. Immunity 2021; 54:412.

3. Rayaprolu V, Fulton BO, Rafique A, et al. Structure of the Inmazeb cocktail and resistance to Ebola virus escape. Cell Host Microbe 2023; 31:260.

THAM

Q: THAM should ideally be infused through central line.

A) True

B) False

Answer: A

THAM stands for Tromethamine (tris-hydroxymethyl aminomethane. Other less popular names are TRIS and trometamol. Although now rarely used, THAM is a viable option in mixed metabolic and respiratory acidosis, as it has two advantages over "bicarb" (H2CO3).

• no sodium load
• no generation of CO2, or may even reduce it

Unfortunately, it is not widely and commercially available, and many institutions prepare their own THAM.

Mechanism of action: THAM is an amino alcohol that buffers hydrogen ions by virtue of its amine (NH2) moiety (pKa = 7.7) via the following two reactions

1.  THAM-NH2 + H+  →  THAM-NH3+
2.  THAM-NH2 + H2O + CO2  →  THAM-NH3+ + HCO3-

The final product is the protonated form of THAM, which requires either a functioning kidney or dialysis. When given via peripheral IV line, extravasation may cause tissue necrosis. Central line is preferred.

#acid-base

References:

1. Nahas GG, Sutin KM, Fermon C, et al. Guidelines for the treatment of acidaemia with THAM. Drugs 1998; 55:191.

2. Kallet RH, Jasmer RM, Luce JM, et al. The treatment of acidosis in acute lung injury with tris-hydroxymethyl aminomethane (THAM). Am J Respir Crit Care Med 2000; 161:1149.

3. Weber T, Tschernich H, Sitzwohl C, et al. Tromethamine buffer modifies the depressant effect of permissive hypercapnia on myocardial contractility in patients with acute respiratory distress syndrome. Am J Respir Crit Care Med 2000; 162:1361.

4. Holmdahl MH, Wiklund L, Wetterberg T, et al. The place of THAM in the management of acidemia in clinical practice. Acta Anaesthesiol Scand 2000; 44:524.

5. Radosevich MA, Wieruszewski PM, Wittwer ED. Tris-Hydroxymethyl Aminomethane in Critically Ill Adults: A Systematic Review. Anesth Analg 2023; 137:1007.

cyproheptadine in serotonin syndrome

Q: 42 years old female is admitted to the ICU with probable serotonin syndrome. Cyproheptadine has been initiated. Cyproheptadine is a? - select one

A) histamine-1 receptor agonist

B) histamine-1 receptor antagonist 

Answer: B

Although cyproheptadine continues to have a debatable role in serotonin syndrome (SS) - see reference #3 -, it is universally used as it has relatively benign side effects, such as sedation (which is actually desired in SS), and hypotension, which can be relatively managed easily. Cyproheptadine has three properties. It is a:

• histamine-1 receptor antagonist 
• nonspecific 5-HT1A and 5-HT2A antagonistic (two subtypes of serotonin receptors)
• though weak, but has needed anticholinergic activity

#neurology

#pharmacology

References:

1. Graudins A, Stearman A, Chan B. Treatment of the serotonin syndrome with cyproheptadine. J Emerg Med 1998; 16:615.

2. Prakash S, Patel H, Kumar S, Shah CS. Cyproheptadine in serotonin syndrome: A retrospective study. J Family Med Prim Care. 2024 Apr;13(4):1340-1346. doi: 10.4103/jfmpc.jfmpc_652_23. Epub 2024 Apr 22. PMID: 38827706; PMCID: PMC11142004.

3. Nguyen H, Pan A, Smollin C, Cantrell LF, Kearney T. An 11-year retrospective review of cyproheptadine use in serotonin syndrome cases reported to the California Poison Control System. J Clin Pharm Ther. 2019 Apr;44(2):327-334. doi: 10.1111/jcpt.12796. Epub 2019 Jan 16. PMID: 30650197.

Mushroom-shaped RBCs

Q: Mushroom-shaped Red Blood Cells (RBCs) signify what?

Answer: Oxidative stress

During the COVID-19 pandemic, Mushroom-shaped RBCs, also known as fish-shaped cells or pincer cells, became a widely used term. They can also be associated with anisocytosis, spherocytes, stomatocytes, and polychromasia. 

They are strongly associated with oxidative stress in RBC physiology. It can also occur in iron deficiency, vitamin B12 or folate deficiency, hepatic insufficiency, hereditary elliptocytosis, MDS, myeloproliferative neoplasms, and acute leukemia.

#hematology

References:

1. Gérard D, Ben Brahim S, Lesesve JF, Perrin J. Are mushroom-shaped erythrocytes an indicator of COVID-19? Br J Haematol 2021; 192:230.

2. Robier C, Körber C, Quehenberger F, et al. The frequency of occurrence of fish-shaped red blood cells in different haematologic disorders. Clin Chem Lab Med 2018; 56:323.

3. Ford J. Red blood cell morphology. Int J Lab Hematol 2013; 35:351.

Emergent blood transfusion with Group O

Q: A 32-year-old male is admitted to the ICU with severe life-threatening shock after an esophageal variceal bleed. Emergency release of blood is ordered. The blood bank informed you that, unfortunately, no Group O, RhD-negative blood is available. Can Group O, RhD-positive blood be transfused?

A) Yes

B) No

Answer: A

In case of emergency, blood released from the bank is typically group O, RhD-negative. But in a situation like our patient in the above question, group O, RhD-positive RBC units can be used. It is popularly known as low-titer O-positive whole blood (LTO+WB). Many blood banks use this approach to preserve O-negative blood units for childbearing women in emergencies.

Also, patients with a confirmed ABO type on a current specimen can receive uncrossmatched, type-specific blood for emergency release. 

In all such situations, pRBC should be infused slowly, with close monitoring for signs of an acute hemolytic transfusion reaction, such as fever, chills, hypotension, hematuria, or chest or flank pain.

#hematology

References:

1. Chowdhury R, Williams BA, Williams S, Casey J. Quality improvement review of O positive blood in emergency transfusion. Transfusion. 2023 Oct;63(10):1841-1848. doi: 10.1111/trf.17537. Epub 2023 Sep 12. PMID: 37698202.

2. Flommersfeld S, Mand C, Kühne CA, Bein G, Ruchholtz S, Sachs UJ. Unmatched Type O RhD+ Red Blood Cells in Multiple Injured Patients. Transfus Med Hemother. 2018 May;45(3):158-161. doi: 10.1159/000485388. Epub 2018 Mar 7. PMID: 29928169; PMCID: PMC6006622.

3. Courcelles L, Pouplard M, Braun O, Streel C, Deneys V. Optimizing O red blood cell concentrate usage in the emergency department in the era of patient blood management. Hematol Transfus Cell Ther. 2024 Nov;46 Suppl 5(Suppl 5):S90-S96. doi: 10.1016/j.htct.2024.05.008. Epub 2024 Aug 21. PMID: 39183144; PMCID: PMC11670554.

four stages of Neurocysticercosis on neuro-imaging

Q: What are the four  stages of Neurocysticercosis on neuro-imaging?

Answer: There are 4 stages of the cyst itself while reviewing brain imaging

• First - Vesicular cyst. Note the well-defined scolex, minimal contrast enhancement, and mass effect.
• Second -  MRI of a colloidal cyst. Note ring enhancement, loss of the scolex, and perilesional edema.
• Third -  MRI of the nodular/granular stage. Note nodule with diffuse enhancement and no cystic component.
• Fourth - Non-contrast computed tomography showing multiple punctuate calcifications.

#ID

#radiology

References:

1. Lopes M, Ferreira M, Ramos I, Melo Freitas P. Neurocysticercosis: a contemporary presentation of the neuroimaging main stages. BMJ Case Rep. 2022 Feb 9;15(2):e247927. doi: 10.1136/bcr-2021-247927. PMID: 35140100; PMCID: PMC8830162.

2. Knott MV, Berke CN, Shah KH, Gurses ME, Bashti M, Lu VM, Ivan ME, Castro JG, Komotar RJ, Shah AH. Neurosurgical Approach to Neurocysticercosis in Adults: A Comprehensive Systematic Review of Clinical and Imaging Insights. Neurosurgery. 2025 Feb 21;97(2):281-297. doi: 10.1227/neu.0000000000003371. PMID: 39982074.

AKI after cardiac bypass

Q: Addition of mannitol to Cardio-pulmonary Bypass (CPB) in the OR reduce the risk of acute kidney injury (AKI) post cardiac surgery?

A) True

B) False

Answer: B

In the past, different modalities have been tried to decrease the risk of AKI post-cardiac surgery, including mannitol, furosemide, and low-dose dopamine (popularly known as renal dose dopamine), but none have been shown to protect against AKI post-bypass. The best approach to prevent AKI post-surgery is to maintain adequate 

• CPB pump flow
• Mean arterial pressure (MAP)
• Mixed Venous Oxygenation (SvO2), and 
• Arterial blood gases (ABGs)

Simultaneously, monitoring urine output to maintain at or above 0.5 mL/kg per hour is the best strategy. If urine output drops, quickly determine the cause by checking bladder catheter (aka Foley) placement, cardiac function, and possible development of aortic dissection via transesophageal echocardiography (TEE).

#surgical-critical-care

#cardiac-surgery

#cardiology

#nephrology

References:

1. junggren M, Sköld A, Dardashti A, Hyllén S. The use of mannitol in cardiopulmonary bypass prime solution-Prospective randomized double-blind clinical trial. Acta Anaesthesiol Scand 2019; 63:1298.

2. Bell S, Ross VC, Zealley KA, et al. Management of post-operative acute kidney injury. QJM 2017; 110:695.

3. Yang X, Zhu L, Pan H, Yang Y. Cardiopulmonary bypass associated acute kidney injury: better understanding and better prevention. Ren Fail. 2024 Dec;46(1):2331062. doi: 10.1080/0886022X.2024.2331062. Epub 2024 Mar 21. PMID: 38515271; PMCID: PMC10962309.

4. Chu H, Li S, Cao L, Xu G, Yang L, Ma C. Risk factors for acute kidney injury after coronary artery bypass graft surgery: a systematic review and meta-analysis. Front Med (Lausanne). 2026 Feb 24;13:1722801. doi: 10.3389/fmed.2026.1722801. PMID: 41816661; PMCID: PMC12971401.

DrawingTacrolimus Trough Level

Q: Which one precaution should be taken while drawing blood for Tacrolimus (FK506) level?

Answer: Tacrolimus can leach into plastic catheters.

In the immediate transplant period, Tacrolimus prophylaxis is initiated via intravenous (IV) infusion. Tacrolimus can leach into plastic catheters, so the Central Venous Catheter (CVC) lumen used to measure serum levels should be separate from the lumen through which tacrolimus is infused; otherwise, serum levels are likely to be falsely elevated.

Tacrolimus should be converted to the oral route whenever the patient can utilize the enteral route. Tacrolimus is almost completely metabolized in the liver, so the half-life of nine hours can be longer in liver insufficiency. 

#transplant

#pharmacology

#laboratory-medicine

References:

1. Hacker C, Verbeek M, Schneider H, Steimer W. Falsely elevated cyclosporin and tacrolimus concentrations over prolonged periods of time due to reversible adsorption to central venous catheters. Clin Chim Acta. 2014 Jun 10;433:62-8. doi: 10.1016/j.cca.2014.02.031. Epub 2014 Mar 11. PMID: 24631133.

2. Han A, Jo AJ, Kwon H, Kim YH, Lee J, Huh KH, Lee KW, Park JB, Jang E, Park SC, Lee J, Lee J, Kim Y, Soliman M, Min S. Optimum tacrolimus trough levels for enhanced graft survival and safety in kidney transplantation: a retrospective multicenter real-world evidence study. Int J Surg. 2024 Oct 1;110(10):6711-6722. doi: 10.1097/JS9.0000000000001800. PMID: 38884261; PMCID: PMC11486932.

3. Yin S, Song T, Jiang Y, Li X, Fan Y, Lin T. Tacrolimus Trough Level at the First Month May Predict Renal Transplantation Outcomes Among Living Chinese Kidney Transplant Patients: A Propensity Score-Matched Analysis. Ther Drug Monit. 2019 Jun;41(3):308-316. doi: 10.1097/FTD.0000000000000593. PMID: 31083041; PMCID: PMC6553958.

Dig in pregnancy

Q: Digoxin is contraindicated in pregnancy?

A) Yes

B) No

Answer: B 

Digoxin is one of the unique medicines that is given to the mother for fetal cardiac indications. It crosses the placenta without causing fetal harm or teratogenicity. Moreover, it can be used in lactation for maternal cardiac indications.

It is mostly used to treat sustained fetal tachyarrhythmias, such as supraventricular tachycardia (SVT) and atrial flutter, and to prevent hydrops fetalis.

#ob-gyn

#pharmacology

#pediatrics

#cardiology

References:

1. Hauptman PJ, Kelly RA. Digitalis. Circulation 1999; 99:1265.

2. Wang C, Zhao L, Shao S, Yu H, Zhou S, Li Y, Zhu Q, Liu X, Duan H, Liu H, Hua Y, Zhou K. Transplacental digoxin treatment for fetal supraventricular arrhythmias: Insights from Chinese fetuses. Chin Med J (Engl). 2025 Jun 20;138(12):1499-1501. doi: 10.1097/CM9.0000000000003583. Epub 2025 Apr 9. PMID: 40204513; PMCID: PMC12180843.

3. Soyka LF. Digoxin: placental transfer, effects on the fetus, and therapeutic use in the newborn. Clin Perinatol. 1975 Mar;2(1):23-35. PMID: 1102216.

catamenial epilepsy

Q: Catamenial epilepsy occurs more frequently in which phase of the menstrual cycle?

A) early 

B) mid

C) late

Answer: C

Catamenial epilepsy can best be predicted by keeping a seizure diary. In a regular menstrual cycle, estrogen levels peak during mid-cycle (without conception) and drop just before the onset of menses. During this period, most seizure clusters are reported. Although a periovulatory seizure may occur. 

Standard treatment of seizures should be sufficient.

Use of Clobazam during the vulnerable phase of the menstrual cycle has shown some promise. 20 to 30 mg of Clobazam per day for 10 days during the high-risk phase of the menstrual cycle has been found to be effective. Intermittent lorazepam may also be used in the vulnerable period.

Some experts recommend the use of an adjunctive continuous estrogen-progestin contraceptive as hormonal prophylaxis for catamenial epilepsy, though evidence is weak for such practice. Other recommended treatments, but with very limited data, are acetazolamide, gonadotropin analogs, and neurosteroids (ganaxolone).

#neurology

#ob-gyn

References:

1. Herzog AG, Fowler KM, Sperling MR, et al. Variation of seizure frequency with ovulatory status of menstrual cycles. Epilepsia 2011; 52:1843.

2. Maguire MJ, Nevitt SJ. Treatments for seizures in catamenial (menstrual-related) epilepsy. Cochrane Database Syst Rev 2021; 9:CD013225.

3. Herzog AG, Fowler KM, Smithson SD, et al. Progesterone vs placebo therapy for women with epilepsy: A randomized clinical trial. Neurology 2012; 78:1959.

4. Feely M, Calvert R, Gibson J. Clobazam in catamenial epilepsy. A model for evaluating anticonvulsants. Lancet 1982; 2:71.

5. Ansell B, Clarke E. Acetazolamide in Treatment of Epilepsy. Br Med J 1956; 1:650.

6. Reddy DS. Neurosteroid replacement therapy for catamenial epilepsy, postpartum depression and neuroendocrine disorders in women. J Neuroendocrinol 2022; 34:e13028.

PP and Carbs

Q: A high-carbohydrate load is recommended in patients who present with hypokalemic Periodic paralysis (PP), including thyrotoxic PP.

A) True

B) False

Answer: B

PP attacks in hypokalemic thyrotoxic patients result from increased release of epinephrine or insulin, causing intracellular potassium shifts and low serum potassium levels. Known inciting events are:

• strenuous physical activity
• stress
• high-carbohydrate load (answer for above Q)
• cold exposure
• infection
• alcohol intake
• pulse corticosteroid therapy
• beta-2 adrenergic bronchodilator 
• menses 
• exogenous epinephrine or insulin
• acetazolamide
• thyroid supplements 

#electrolytes

References:

1. Hsieh MJ, Lyu RK, Chang WN, et al. Hypokalemic thyrotoxic periodic paralysis: clinical characteristics and predictors of recurrent paralytic attacks. Eur J Neurol 2008; 15:559.

2. Qing G, Zakaria WNA, Rom FZM, Nik WNFHW, Zulkeflee HA, Rahim SNA. Thyrotoxic Hypokalemic Periodic Paralysis: Pathophysiological Mechanisms. Endocrinol Metab (Seoul). 2025 Dec;40(6):821-829. doi: 10.3803/EnM.2025.2554. Epub 2025 Dec 11. PMID: 41376301; PMCID: PMC12765881.

3. Chang CC, Cheng CJ, Sung CC, et al. A 10-year analysis of thyrotoxic periodic paralysis in 135 patients: focus on symptomatology and precipitants. Eur J Endocrinol 2013; 169:529.

MH and gender

Q: Malignant Hyperthermia (MH) is disproportionally high in? - select one

A) males

B) females

Answer: A

The male-to-female ratio for MH is 2:1. The obvious explanation is the likely higher skeletal mass in males, though it does not fully account for the high prevalence in males. Moreover, children less than 19 years of age are more prone to develop MH.

#anesthesia

References:

1. Brady JE, Sun LS, Rosenberg H, Li G. Prevalence of malignant hyperthermia due to anesthesia in New York State, 2001-2005. Anesth Analg 2009; 109:1162.

2. Larach MG, Gronert GA, Allen GC, et al. Clinical presentation, treatment, and complications of malignant hyperthermia in North America from 1987 to 2006. Anesth Analg 2010; 110:498.

3. Rosenberg H, Davis M, James D, et al. Malignant hyperthermia. Orphanet J Rare Dis 2007; 2:21.

4. Rosenberg H, Pollock N, Schiemann A, Bulger T, Stowell K. Malignant hyperthermia: a review. Orphanet J Rare Dis. 2015 Aug 4;10:93. doi: 10.1186/s13023-015-0310-1. PMID: 26238698; PMCID: PMC4524368.

Metronidazole and disulfiram-like reactions.

Q: Metronidazole should be avoided with alcohol intake as it may cause disulfiram-like reactions.

A) True

B) False

Answer: B

Although it was once believed that metronidazole could cause disulfiram-like reactions with ETOH, this was based on a few weak reports. Evidence failed to prove any such association. The United States Centers for Disease Control and Prevention (CDC) Sexually Transmitted Infection Guidelines in 2021 removed abstaining from alcohol while taking metronidazole.

Metronidazole does not inhibit alcohol metabolism in the liver or increase blood acetaldehyde production, the basis for disulfiram-like reactions. It is suggested that metronidazole and ethanol both, independently, increase brain serotonin levels, potentially giving an impression of disulfiram-like reactions.

# pharmacology

References:

1. Visapää JP, Tillonen JS, Kaihovaara PS, Salaspuro MP. Lack of disulfiram-like reaction with metronidazole and ethanol. Ann Pharmacother 2002; 36:971.

2. Tillonen J, Väkeväinen S, Salaspuro V, et al. Metronidazole increases intracolonic but not peripheral blood acetaldehyde in chronic ethanol-treated rats. Alcohol Clin Exp Res 2000; 24:570.

3. Karamanakos PN, Panteli ES, Marselos M. Comment on 'Can Metronidazole Cause a Disulfiram-Like Reaction? A Case-Control Study Propensity Matched By Age, Sex and Ethanol. WMJ 2024; 123:3.

4. Workowski KA, Bachmann LH, Chan PA, et al. Sexually Transmitted Infections Treatment Guidelines, 2021. MMWR Recomm Rep 2021; 70:1.

5. Feldman R, Jaszczenski R. Can Metronidazole Cause a Disulfiram-Like Reaction? A Case-Control Study Propensity Matched by Age, Sex, and Ethanol Concentration. WMJ 2023; 122:171.

Acute HIV on PrEP

Q: What's the caveat of diagnosing HIV in patients who are using pre-exposure prophylaxis (PrEP) for HIV?

Answer: Unreliable clinical signs and routine HIV screening test

Patients who are on pre-exposure prophylaxis (PrEP) due to their lifestyle may not develop full-blown acute HIV symptoms on initial contraction, but may have mild symptoms called pauci-symptomatic acute HIV. Cardinal acute HIV symptoms such as fever and rash are usually absent, and there may be no pharyngitis or diarrhea. To make things more complicated, routine HIV screening with the antigen/antibody test may not be reliable. Diagnosis can be made by history, exposure, keeping a high clinical suspicion, and HIV RNA as the screening tool.

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References:

1. Landovitz RJ, Delany-Moretlwe S, Fogel JM, et al. Features of HIV Infection in the Context of Long-Acting Cabotegravir Preexposure Prophylaxis. N Engl J Med 2024; 391:1253.

2. Moschese D, Lazzarin S, Colombo ML, Caruso F, Giacomelli A, Antinori S, Gori A. Breakthrough Acute HIV Infections among Pre-Exposure Prophylaxis Users with High Adherence: A Narrative Review. Viruses. 2024 Jun 12;16(6):951. doi: 10.3390/v16060951. PMID: 38932243; PMCID: PMC11209220.

3. Elliott T, Sanders EJ, Doherty M, Ndung'u T, Cohen M, Patel P, Cairns G, Rutstein SE, Ananworanich J, Brown C, Fidler S. Challenges of HIV diagnosis and management in the context of pre-exposure prophylaxis (PrEP), post-exposure prophylaxis (PEP), test and start and acute HIV infection: a scoping review. J Int AIDS Soc. 2019 Dec;22(12):e25419. doi: 10.1002/jia2.25419. PMID: 31850686; PMCID: PMC6918508.

Calcium and Dengue Virus

Q: Dengue virus infection causes? - select one

A) hypercalcemia

B) hypocalcemia 

Answer: B

Most of the treatment for the Dengue virus during all three phases of the Dengue virus, i.e., early, critical, and recovery phase, is essentially supportive. One of the unique features of the Dengue virus is hypocalcemia, and its cause is still not well understood. That said, it is significant, as the level of hypocalcemia correlates with the severity of illness. Its clinical significance can be understood from the perspective that, in resource-limited countries where the dengue virus is common, and labs may not be readily available, calcium should be replaced empirically, correlating clinically with the level of shock.

Development of seizures or arrhythmia due to hypocalcemia predicts poor outcome and requires constant monitoring and replacement, particularly in the critical phase. IV calcium gluconate is preferred. Replacement of calcium also helps restore the coagulation defects, a cardinal feature of Dengue virus infection.

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References;

1. Pourzangiabadi M, Najafi H, Fallah A, Goudarzi A, Pouladi I. Dengue virus: Etiology, epidemiology, pathobiology, and developments in diagnosis and control - A comprehensive review. Infect Genet Evol. 2025 Jan;127:105710. doi: 10.1016/j.meegid.2024.105710. Epub 2024 Dec 26. PMID: 39732271.

2. Shivanthan MC, Rajapakse S. Dengue and calcium. Int J Crit Illn Inj Sci 2014; 4:314.

3. Constantine GR, Rajapakse S, Ranasinghe P, et al. Hypocalcemia is associated with disease severity in patients with dengue. J Infect Dev Ctries 2014; 8:1205.