urine alkalinization

Q: Acetazolamide is a good choice for urinary alkalinization when sodium bicarbonate is contraindicated.

A) True

B) False

Answer: B

Although acetazolamide alkalinizes the urine, it simultaneously lowers the systemic pH, which defeats the purpose and may harm the patient.

Urinary alkalinization is a primary mode of treatment in many drug overdoses. All drugs that meet the following criteria can be treated with urinary alkalinization:

• predominantly eliminated unchanged by the kidney
• distributed primarily in the extracellular fluid compartment (low volume of distribution)
• minimally protein-bound
• weak acids with pKa ranging from 3.0 to 7.5

The most common are: Salicylates, Methotrexate, Barbiturates, Phenobarbital, Primidone and Sulfonamides

Using sodium bicarbonate to achieve a urine pH of 7.5 or higher while maintaining a serum pH no higher than 7.55 to 7.6 is the primary way to alkalinize urine. Unfortunately, kidney failure, pulmonary edema (volume overload), and/or cerebral edema, and severe concomitant hypokalemia are some of the contraindications for its use.

Sodium acetate as a replacement for sodium bicarbonate has been used in some cases where it is not available, though it can be given only as an infusion without a bolus (reference # 3).

#toxicology

#acid-base

References:

1. Proudfoot AT, Krenzelok EP, Vale JA. Position Paper on urine alkalinization. J Toxicol Clin Toxicol 2004; 42:1.

2. Garrettson LK, Geller RJ. Acid and alkaline diuresis. When are they of value in the treatment of poisoning? Drug Saf 1990; 5:220.

3. Neavyn MJ, Boyer EW, Bird SB, Babu KM. Sodium acetate as a replacement for sodium bicarbonate in medical toxicology: a review. J Med Toxicol 2013; 9:250.

2 major types of Hanta virus

Q: Which of the following is NOT described (yet) as one of the two Hantavirus severe acute febrile illnesses? - select one

A) Hantavirus cardiopulmonary syndrome 

B) Hemorrhagic fever with hepatic syndrome

C) Hemorrhagic fever with renal syndrome 

Answer: B

So far, Hantaviruses are clinically associated with two severe acute febrile illnesses.

• Hemorrhagic fever with renal syndrome (HFRS) 
• Hantavirus cardiopulmonary syndrome (HCPS)

HFRS is mostly reported in Korean (Asian) people and, as the name implies, has two components and five phases. It primarily damages small blood vessels and leads to acute kidney injury (AKI). The five phases are: febrile, hypotensive, oliguric, diuretic, and convalescent.

HCPS is reported mostly in the SW USA area (though it can occur anywhere). It has three phases: prodromal, cardiopulmonary, and recovery. With ongoing wide availability of ECMO in the USA, there is hope that, once expected to be a very high-mortality disease, it will offer good recovery despite more and more cases being reported.

#ID

References:

1. Tariq M, Kim DM. Hemorrhagic Fever with Renal Syndrome: Literature Review, Epidemiology, Clinical Picture and Pathogenesis. Infect Chemother. 2022 Mar;54(1):1-19. doi: 10.3947/ic.2021.0148. PMID: 35384417; PMCID: PMC8987181.

2. Ulloa-Morrison R, Pavez N, Parra E, Lopez R, Mondaca R, Fernandez P, Kraunik D, Sanhueza C, Bravo S, Cornu MG, Kattan E. Critical care management of hantavirus cardiopulmonary syndrome. A narrative review. J Crit Care. 2024 Dec;84:154867. doi: 10.1016/j.jcrc.2024.154867. Epub 2024 Jul 17. PMID: 39024823.

3. Rao A, Tariq H. Hantavirus cardiopulmonary syndrome: an emerging fatal zoonotic infection. Infection. 2026 Oct 3. doi: 10.1007/s15010-026-02994-6. Epub ahead of print. PMID: 42828628.

PCC and aPCC

Q: Activation of which blood coagulation factor converts Unactivated prothrombin complex concentrate (PCC) to activated PCC (aPCC)? - select one

A) factor II

B) factor VII

C) factor IX

d) factor X

E) Protein C

Answer: B

At the definition level: 

- Unactivated PCC contains vitamin K-dependent coagulation factors, which can be either 3-factor (factors II, IX, X) or 4-factor (factors II, VII, IX, X). The factors are all inactive.

- Activated aPCC also contains inactive factors II, IX, and X, variable inactive factor VII, BUT a significant portion of activated factor VII (factor VIIa). It also contains small amounts of some other activation products.

Thrombotic risks have always been a concern with both PCC and aPCC administration.

#hematology

References:

1. van den Brink DP, Wirtz MR, Neto AS, Schöchl H, Viersen V, Binnekade J, Juffermans NP. Effectiveness of prothrombin complex concentrate for the treatment of bleeding: A systematic review and meta-analysis. J Thromb Haemost. 2020 Oct;18(10):2457-2467. doi: 10.1111/jth.14991. Epub 2020 Aug 2. PMID: 32638483; PMCID: PMC7589201.

2. Sheikh-Taha M, Crawley RM. Efficacy and safety of activated prothrombin complex concentrate for the reversal of vitamin K antagonist major bleeding. Sci Rep. 2022 Feb 2;12(1):1814. doi: 10.1038/s41598-022-05803-w. PMID: 35110612; PMCID: PMC8810750.

3. Crawley RM, Sheikh-Taha M. Comparison of activated and 4-factor prothrombin complex concentrates for reversal of apixaban- and rivaroxaban-associated major bleeding. J Thromb Thrombolysis. 2026 Mar;59(3):610-615. doi: 10.1007/s11239-025-03232-w. Epub 2026 Jan 12. PMID: 41525014.

Intestinal ischemia after abdominal aortic surgery

Q: 52 years old male is admitted to the ICU after abdominal aortic dissection repair. 24 hours post-surgery, the patient complains of acute abdominal pain. CTA of the abdomen is consistent with acute colonic ischemia. Which side of the colon is probably affected?

A) Left

B) Right

Answer: A

With open aortic surgery, colonic ischemia almost always affects the distal left colon. Some of the surgical causes are:

• loss of collateral flow due to inferior mesenteric artery ligation
• iliac artery ligation
• embolic events
• vascular compression with surgical instruments
• hypotension leading to hypoperfusion

On a similar note, some cardiac interventions, such as cardiac catheterization or valve implantation, can also cause colonic ischemia.

#surgical-critical-care

#GI

References:

1. Abromaitis D, Antusevas A. Zarnyno isemijos prevencija po pilvo aortos rekonstrukciniu operaciju [Prevention of intestinal ischemia after abdominal aortic reconstructive surgery]. Medicina (Kaunas). 2005;41(4):295-304. Lithuanian. PMID: 15864002.

2. Ding P, Zhou Y, Long KL, Zhang S, Gao PY. Acute mesenteric ischemia due to percutaneous coronary intervention: A case report. World J Clin Cases. 2022 Oct 6;10(28):10244-10251. doi: 10.12998/wjcc.v10.i28.10244. PMID: 36246830; PMCID: PMC9561597.

3. Michalopoulos GC, Bikeyeva V, Paolella G, Adams J, Labchuk A, Chaus A. Non-occlusive Mesenteric Ischemia Following Transcatheter Aortic Valve Replacement: A Case Report. Cureus. 2025 Jul 7;17(7):e87468. doi: 10.7759/cureus.87468. PMID: 40630765; PMCID: PMC12237081.

FIB-4 Index

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Q: Which of the following is NOT part of the Fibrosis-4 (FIB-4) Index in liver diseases?

A) Age 

B) ALT

C) AST

D) Bilirubin

E) Platelets

Answer: D

MASLD was previously known as nonalcoholic fatty liver disease (NAFLD). The FIB-4 score is used to assess fibrosis and cirrhosis. It applies to patients aged 35 and older. It is based on the formula:

FIB-4 = Age * AST / (0.001 * Platelets * sqr(ALT)) 

The formula uses US units.

Cutoff values for suspecting liver fibrosis vary by study and by the etiology of liver disease. The FIB-4 index Risk:

• <1.3  = Advanced fibrosis/cirrhosis less likely
• ≥1.3 and ≤2.67  = Indeterminate
• >2.67   = Advanced fibrosis/cirrhosis more likely

  

FIB-4 index is found to have a good predictive accuracy for advanced fibrosis, particularly in patients with chronic Hepatitis C (HCV) and in patients with Metabolic Dysfunction-Associated Steatotic Liver Disease (MASLD), which was previously known as nonalcoholic fatty liver disease (NAFLD), where the area under the ROC curve for predicting adverse liver-related outcomes was 0.81 and for predicting death or liver transplantation was 0.67.

  

FIB-4 values have also been associated with the risk of developing hepatocellular carcinoma (HCC) in alcoholic patients, where it is used in correlation with the level of alcohol consumption.

  

#hepatology

  

  

References:

  

 1. Angulo P, Bugianesi E, Bjornsson ES, et al. Simple noninvasive systems predict long-term outcomes of patients with nonalcoholic fatty liver disease. Gastroenterology 2013; 145:782.

  

 2. Vallet-Pichard A, Mallet V, Nalpas B, et al. FIB-4: an inexpensive and accurate marker of fibrosis in HCV infection. comparison with liver biopsy and fibrotest. Hepatology 2007; 46:32.

  

 3. Suh B, Yun JM, Park S, et al. Prediction of future hepatocellular carcinoma incidence in moderate to heavy alcohol drinkers with the FIB-4 liver fibrosis index. Cancer 2015; 121:3818.

  

 4. Sterling RK, Patel K, Duarte-Rojo A, et al. AASLD Practice Guideline on blood-based noninvasive liver disease assessment of hepatic fibrosis and steatosis. Hepatology 2025; 81:321.

transfusions in kidney transplant patients

Q: All post-kidney transplant patients should receive irradiated blood if transfusion is required.

A) Yes

B) No

Answer: B

Ideally, all blood transfusions should be avoided in any awaiting or solid organ transplant patients as far as possible to minimize the risk of allosensitization and rejection. If transfusion becomes necessary, order cytomegalovirus (CMV)-seronegative and/or filtered blood products instead of only leukocyte-reduced products, as CMV infection may occur even with only leukoreduced blood transfusion (reference #1). 

Blood product irradiation is not required.

#transfusion

#transplantation

References:

1. Obrador GT, Macdougall IC. Effect of red cell transfusions on future kidney transplantation. Clin J Am Soc Nephrol 2013; 8:852.

2. Nichols WG, Price TH, Gooley T, et al. Transfusion-transmitted cytomegalovirus infection after receipt of leukoreduced blood products. Blood 2003; 101:4195.

3. Triulzi DJ. Specialized transfusion support for solid organ transplantation. Curr Opin Hematol 2002; 9:527.

Pseudo-Cushing

Q: Patients with physiologic hypercortisolism are more prone to have proximal muscle atrophy and weakness.

A) True 

B) False

Answer: B

When hypercortisolism occurs in any disorder other than Cushing syndrome, it is called physiologic or pseudo-Cushing syndrome. These patients usually are spared of some cardinal signs of true Cushing syndrome, such as easy bruising, thinning, friability) or proximal muscle atrophy and weakness.

Some well-known conditions/disorders causing physiologic hypercortisolism and Cushing syndrome are:

• Pregnancy
• Severe obesity
• Polycystic ovary syndrome (PCOS)
• Psychological stress
• Poorly controlled diabetes mellitus
• Chronic alcoholism, particularly during withdrawal
• Severe illness
• Obstructive sleep apnea
• Intense chronic exercise
• Hypothalamic amenorrhea

#endocrinology

References:

1. Arnaldi G, Angeli A, Atkinson AB, et al. Diagnosis and complications of Cushing's syndrome: a consensus statement. J Clin Endocrinol Metab 2003; 88:5593.

2. Chabre O. The difficulties of pseudo-Cushing's syndrome (or "non-neoplastic hypercortisolism"). Ann Endocrinol (Paris). 2018 Jun;79(3):138-145. doi: 10.1016/j.ando.2018.04.017. Epub 2018 Apr 30. PMID: 29716734.

3. Pecori Giraldi F, Ambrogio AG. Pseudo-Cushing - A Clinical Challenge? Front Horm Res. 2016;46:1-14. doi: 10.1159/000443859. Epub 2016 May 17. PMID: 27211794.

humidification of inspired gas

Q: What are the few advantages of humidifying the oxygen via High Flow Nasal Cannula (HFNC)?

Answer: It is standard practice to warm and humidify inspired oxygen to body temperature, especially when delivering high-flow oxygen, typically above 40 L/minute. This increased humidification serves three main purposes:

• increased water content in mucus, which facilitates secretion removal
• decreases the work of breathing (WOB), and 
• avoids airway desiccation and so prevents epithelial injury 

#respiratory

References:

1. Williams R, Rankin N, Smith T, et al. Relationship between the humidity and temperature of inspired gas and the function of the airway mucosa. Crit Care Med 1996; 24:1920.

2. Hasani A, Chapman TH, McCool D, et al. Domiciliary humidification improves lung mucociliary clearance in patients with bronchiectasis. Chron Respir Dis 2008; 5:81.

SWD

Q: For ICU night shift workers, studies have shown that a short nap during the shift improves efficacy. The nap during the night shift is preferred in? - select one

A) early part of the shift

B) later part of the shift

Answer: B

ICU is a 24/7 business! It requires nurses, physicians, and other staff to work night shifts. The situation becomes tricky for staff who frequently alternate day and night shifts. It markedly disturbs their circadian rhythm. Over decades, staff have tried various strategies, including sleep hygiene, avoiding light exposure, sleep diaries, actigraphy, caffeine, and pharmacological interventions, including over-the-counter options (like melatonin) and prescription medications (like zolpidem and others).  The International Classification of Sleep Disorders now officially defines it as shift work disorder (SWD) (reference # 1). Many hospitals now officially allow staff to take these breaks.

Various studies (see references 2-5) show that naps help improve SWD. That said, it is important that:

1. Naps can be limited to under an hour. This minimizes the risk of entering deep sleep and reduces disorientation from sleep inertia upon waking.

2. Naps should be planned either prior to the shift as much as possible, considering time to get ready, commuting, and getting a hand-off report, or preferably in the later part of the shift. This also helps prevent car accidents, which occur more frequently among night-shift staff.

#sleep

#administrative

References:

1. American Academy of Sleep Medicine. International Classification of Sleep Disorders, 3rd ed, text revision, American Academy of Sleep Medicine, 2023.

2. Sallinen M, Härmä M, Akerstedt T, et al. Promoting alertness with a short nap during a night shift. J Sleep Res 1998; 7:240.

3. Purnell MT, Feyer AM, Herbison GP. The impact of a nap opportunity during the night shift on the performance and alertness of 12-h shift workers. J Sleep Res 2002; 11:219.

4. Garbarino S, Mascialino B, Penco MA, et al. Professional shift-work drivers who adopt prophylactic naps can reduce the risk of car accidents during night work. Sleep 2004; 27:1295.

5. Bonnefond A, Muzet A, Winter-Dill AS, et al. Innovative working schedule: introducing one short nap during the night shift. Ergonomics 2001; 44:937.

Preload / afterload in acute pulmonary edema

Q: Acute (Flash) pulmonary edema due to increased preload occurs in all of the following situations EXCEPT?

A) Volume overload 

B) Acute aortic regurgitation

C) Acute mitral regurgitation 

D) Hypertensive crisis

Answer: D

Excess afterload is the major driving force behind acute pulmonary edema in hypertensive crisis, though it may occur with or without increased preload.

All other choices in the above question are due to preload excess.

#hemodynamic

References:

Collins S, Martindale J. Optimizing Hypertensive Acute Heart Failure Management with Afterload Reduction. Curr Hypertens Rep. 2018 Feb 24;20(1):9. doi: 10.1007/s11906-018-0809-7. PMID: 29478124.

Daptomycin-Induced Eosinophilic Pneumonia

Q: What is the easiest way to predict the risk of Daptomycin-induced eosinophilic pneumonia?

Answer: Eosinophilia ≥5 percent 

Daptomycin is one of the most common drugs known to cause drug-induced eosinophilic pneumonia. Major risk factors are

• male sex
• kidney dysfunction
• older age
• hypertension
• duration of treatment >2 weeks at symptom onset 

Daptomycin binds to pulmonary surfactant and may cause cellular damage, oxidative injury, and inflammation of the lung epithelium. It may also induce an allergic reaction, causing T-lymphocyte release, followed by interleukin release and eosinophil migration.

Although bronchoalveolar lavage (BAL) demonstrating >25 percent eosinophils is a diagnostic criterion, not all patients reach that level.

Patients on daptomycin treatment who develop eosinophilia ≥5 percent may be at risk for eosinophilic pneumonia.

Treatment is supportive care.

#pulmonary

#nepheology

References:

1. Pham TT, Garreau R, Craighero F, et al. Seventeen Cases of Daptomycin-Induced Eosinophilic Pneumonia in a Cohort of Patients Treated for Bone and Joint Infections: Proposal for a New Algorithm. Open Forum Infect Dis 2022; 9:ofac577.

2. Gidari A, Pallotto C, Francisci D. Daptomycin eosinophilic pneumonia, a systematic review of the literature and case series. Infection 2024; 52:2145.

3. West KA, Sheeti A, Tamura MacKay K, Forrest GN. Eosinophilic Syndromes Associated With Daptomycin Use: Re-exposure Hypersensitivity Pneumonitis and Prior Peripheral Eosinophilia. Open Forum Infect Dis 2022; 9:ofac065.

large-volume thoracentesis and RPE

Q: More than 1.5 L of pleural fluid (large-volume thoracentesis) should never be removed to avoid re-expansion pulmonary edema (RPE).

A) True

B) False

Answer: B

Although it is conventionally believed that large-volume thoracentesis (i.e., more than 1 to 1.5 L) should never be attempted because it greatly increases the risk of RPE, evidence shows that RPE does not appear to be associated with the volume of fluid removed. Instead, consider patient comfort, ease of flow, and relief of discomfort. Clinically, as long as no chest discomfort develops, and quantitatively, as long as end-expiratory pleural pressure stays less than -20 cm H2O, pleural effusion can be continued to be drained. Interestingly, but not surprisingly, manometric pleural pressure measurement during large-volume thoracentesis does not alter procedure-related chest discomfort. 

In short, pleural effusion volume removal is more of a clinical decision than a fixed number!

#procedures

#pulmonary

References:

1. Feller-Kopman D, Berkowitz D, Boiselle P, Ernst A. Large-volume thoracentesis and the risk of reexpansion pulmonary edema. Ann Thorac Surg 2007; 84:1656.

2. Lentz RJ, Lerner AD, Pannu JK, et al. Routine monitoring with pleural manometry during therapeutic large-volume thoracentesis to prevent pleural-pressure-related complications: a multicentre, single-blind randomised controlled trial. Lancet Respir Med 2019; 7:447.

Predicting kidney stone composition

Q: Which of the following modalities is best for determining stone composition in nephrolithiasis?

A) Noncontrast CT 

B) Low-radiation-dose CT 

C) Dual-energy CT 

D) MRI

E) Ultrasound

Answer: C

Dual-energy CT (DECT) uses scanners that emit two separate radiograph energy sets to differentiate matter's attenuation properties and better characterize stone composition. Many centers in the USA now use DECT routinely to determine kidney stone composition. Adding a deep-learning method to generate DECT images from single-energy images provides more precise diagnosis of kidney stone composition.

Another method not included in the options above is "machine Learning algorithms of endoscopic video images" during ureteroscopic or percutaneous stone removal, which may accurately determine stone composition.

#urology

#radiology

#nephrology

References:

1. Matlaga BR, Kawamoto S, Fishman E. Dual source computed tomography: a novel technique to determine stone composition. Urology 2008; 72:1164.

2. Zhu G, Li C, Guo Y, et al. Predicting stone composition via machine-learning models trained on intra-operative endoscopic digital images. BMC Urol 2024; 24:5.

tracheal intubation in burn patients

Q: All of the following are indications of tracheal intubation in burn patients EXCEPT

A) Hoarseness

B) Carbonaceous sputum 

C) Elevated carboxyhemoglobin (COHb) level

D) Superficial flash burns on the face

E) Circumferential neck burns

Answer: D

Although intubation is a clinical decision, cautious intubation is preferred in burn patients when clinical signs are not reassuring (a do-or-not-do situation). 

Said that a few clinical signs may be taken lightly but may be the tip of an iceberg of impending doom. This question aims to help students understand that post-burn hoarseness (choice A) may seem mild but can require intubation. On the other spectrum, exclusive superficial facial burns sparing the neck (choice D) rarely involve the airway and can be watched closely. Some of the other signs that probably indicate preemptive intubation are:

• Persistent cough
• Stridor
• Wheezing
• Deep facial burn
• Circumferential neck burns (choice E)
• Nares with singed hair (usually associated with other signs)
• Carbonaceous sputum (choice B)
• Burnt matter in mouth or nose
• Blistering or edema of the oropharynx
• Depressed mental status
• Elevated carboxyhemoglobin (COHb) level (choice C)

We added three relevant review articles to the reference section below.

#burn

#procedures

References:

1. Concannon E, Damkat Thomas L, Kerr L, Damkat I, Reddi B, Greenwood JE, Solanki NS, Wagstaff MJD. Review of Indications for Endotracheal Intubation in Burn Patients with Suspected Inhalational Injury. Eur Burn J. 2023 Mar 29;4(2):163-172. doi: 10.3390/ebj4020014. PMID: 39599924; PMCID: PMC11571857.

2. Wardhana A, Farhana N. Early intubation decisions in burn-related inhalation injury: a systematic review of the utility of physical findings in rural and low-resource healthcare settings. Trauma Surg Acute Care Open. 2026 Jul 2;11(3):e002208. doi: 10.1136/tsaco-2025-002208. PMID: 42404874; PMCID: PMC13331052.

3. Badulak JH, Schurr M, Sauaia A, Ivashchenko A, Peltz E. Defining the criteria for intubation of the patient with thermal burns. Burns. 2018 May;44(3):531-538. doi: 10.1016/j.burns.2018.02.016. Epub 2018 Mar 13. PMID: 29548862.

DCB

Q: 58-year-old male with a severe history of bleeding peptic ulcer is admitted to the coronary ICU with acute coronary syndrome. The patient is stabilized with standard anti-anginal treatment. Cardiology is considering Drug-coated balloon angioplasty (DCB) instead of a drug-eluting stent due to his known history. Which drugs are used in DCB?

Answer: Paclitaxel with either iopromode or urea

DCB is getting increasing popularity instead of DES in patients with in-stent restenosis, de novo lesions in small coronary arteries, and in patients with high risk of bleeding after stenting due to dual antiplatelet therapy (DAPT). The other drugs that have been combined with Paclitaxel are either iopromide or urea.

Paclitaxel is a cytostatic agent that binds to tubulin inside cells, blocking normal cell division and chromosome separation. Iopromide is added as a carrier to transfer and release the paclitaxel into the arterial wall. Paclitaxel is lipophilic and may not dissolve or may stick to the balloon surface on its own. Iopromide, a water-soluble, low-osmolality contrast medium, helps paclitaxel rapidly absorb into the intima within seconds, inhibiting smooth muscle cell proliferation and preventing restenosis. Iopromide dissolves safely in blood and is well tolerated by vascular tissue without causing inflammation.

Few studies have used Urea instead of iopromide, as urea acts as a spacer that prevents paclitaxel molecules from clumping together, with a more even, reproducible, and uniform transfer and absorption of the drug into the targeted vascular tissue within 30 to 60 seconds of balloon inflation.

#cardiology

#pharmacology

References:

1. Gitto M, Tartaglia F, Leone PP, Calamita G, Gabrielli A, Gramss L, Rossi ML, Regazzoli D, Gasparini G, Cozzi O, Reimers B, Stefanini GG, Mangieri A, Latib A, Colombo A. Paclitaxel-coated balloon with urea or iopromide as the excipient for treatment of coronary artery disease. Clin Res Cardiol. 2026 Jan;115(1):89-98. doi: 10.1007/s00392-025-02758-6. Epub 2025 Oct 27. PMID: 41143901.

2. von Koch S, Frank E, Gabrysch K, James S, Götberg M, Mohammad MA, Erlinge D. Real-World Usage of a Paclitaxel-Coated Balloon With Urea Compared With Other Contemporary Drug-Coated Balloons: A 2-Year Analysis From SCAAR in Over 6000 Patients. J Am Heart Assoc. 2026 Jun 2;15(11):e045621. doi: 10.1161/JAHA.125.045621. Epub 2026 May 29. PMID: 42216271; PMCID: PMC13315143.

3. Rissanen TT, Uskela S, Eränen J, et al. Drug-coated balloon for treatment of de-novo coronary artery lesions in patients with high bleeding risk (DEBUT): a single-blind, randomised, non-inferiority trial. Lancet 2019; 394:230.

4. Jeger RV, Farah A, Ohlow MA, et al. Long-term efficacy and safety of drug-coated balloons versus drug-eluting stents for small coronary artery disease (BASKET-SMALL 2): 3-year follow-up of a randomised, non-inferiority trial. Lancet 2020; 396:1504.

PSA level and drugs

Q: Regular use of acetaminophen may cause falsely ____________ level of Prostate Specific Antigen (PSA). - Select one

A) elevated

B) lowered

Answer: B

Although it is known that a regular intake of 5-alpha-reductase inhibitors (like finasteride and dutasteride) decreases PSA by almost 50 percent, it is less known that regular use of NSAIDs and acetaminophen can also give lower PSA levels when compared with men not taking these drugs. This correlation is time-dependent, meaning longer duration of use may cause even lower PSA values, particularly in patients who are habitual users of NSAIDs, possibly due to the anti-inflammatory properties of these drugs.

Similarly, statin or thiazide use for over a year may lower PSA levels.

Either adjust PSA levels in these patients or interpret them with more caution.

#Urology

#pharmacology

References:

1.Etzioni RD, Howlader N, Shaw PA, et al. Long-term effects of finasteride on prostate specific antigen levels: results from the prostate cancer prevention trial. J Urol 2005; 174:877.

2. Singer EA, Palapattu GS, van Wijngaarden E. Prostate-specific antigen levels in relation to consumption of nonsteroidal anti-inflammatory drugs and acetaminophen: results from the 2001-2002 National Health and Nutrition Examination Survey. Cancer 2008; 113:2053.

3. Chang SL, Harshman LC, Presti JC Jr. Impact of common medications on serum total prostate-specific antigen levels: analysis of the National Health and Nutrition Examination Survey. J Clin Oncol 2010; 28:3951.

Medical Rx of Cushing's

Q: Which antifungal drug can be used as the primary medical treatment in hypercortisolism? - Select one

A) Fluconazole 

B) Itraconazole 

C) Ketoconazole 

D) Miconazole

E Voriconazole 

Answer:  C

Although hypercortisolism in Cushing syndrome is primarily treated surgically, in a few cases where surgery is not an option, medical treatment is pursued. Ketoconazole is the primary agent in these cases; interestingly, in the United States, it is used off-label to treat hypercortisolism.

Ketoconazole is a racemic mixture of L- and D-form enantiomers and has two targets. First, it inhibits the first step in cortisol biosynthesis, i.e., side-chain cleavage. Second, it inhibits the conversion of 11-deoxycortisol to cortisol. For this reason, it may also decrease the production of other steroid hormones.

#endocrinology

References:

1. Castinetti F, Guignat L, Giraud P, et al. Ketoconazole in Cushing's disease: is it worth a try? J Clin Endocrinol Metab 2014; 99:1623.

2. Viecceli C, Mattos ACV, Costa MCB, de Melo RB, Rodrigues TDC, Czepielewski MA. Evaluation of ketoconazole as a treatment for Cushing's disease in a retrospective cohort. Front Endocrinol (Lausanne). 2022 Oct 7;13:1017331. doi: 10.3389/fendo.2022.1017331. PMID: 36277689; PMCID: PMC9585352.

RESP score

Q: A 53-year-old male with viral pneumonia developed severe ARDS post-intubation, requiring deep sedation along with neuromuscular blockade (NMB) without much improvement, and ECMO evaluation was initiated. ECMO team asks to calculate the RESP (Respiratory ECMO Survival Prediction) Score. NMB prior to ECMO insertion is considered a __________ sign for survival. (Select one).

A) good

B) bad

Answer: A

RESP (Respiratory ECMO Survival Prediction) Score looks into the following components prior to ECMO cannulation:

• Age
• Immunocompromised status
• Malignancy, solid organ transplant, HIV, or cirrhosis
• Mechanically ventilated before ECMO initiation
• Diagnosis (if reversible)
• History of central nervous system dysfunction
• Neurotrauma, stroke, encephalopathy, cerebral embolism, or seizure/epilepsy
• Acute associated nonpulmonary infection
• Any other bacterial, viral, parasitic, or fungal infection not involving the lung
• Neuromuscular blockade before ECMO
• Nitric oxide before ECMO
• Bicarbonate infusion before ECMO
• Cardiac arrest before ECMO
• PaCO₂ ≥75 mmHg (≥10 kPa)
• Peak inspiratory pressure ≥42 cm H₂O (≥4.1 kPa)

Most components decrease survival, except short ventilator time, NMB before ECMO, and reversible diagnoses like asthma.

A score calculator is available on any search engine.

#pulmonary

#ECMO

Reference:

Schmidt M, Bailey M, Sheldrake J, Hodgson C, Aubron C, Rycus PT, Scheinkestel C, Cooper DJ, Brodie D, Pellegrino V, Combes A, Pilcher D. Predicting survival after extracorporeal membrane oxygenation for severe acute respiratory failure. The Respiratory Extracorporeal Membrane Oxygenation Survival Prediction (RESP) score. Am J Respir Crit Care Med. 2014 Jun 1;189(11):1374-82. doi: 10.1164/rccm.201311-2023OC. PMID: 24693864.

Acute metronidazole-induced neurotoxicity

Q: Metronidazole neurotoxicity can be diagnosed and can be distinguished when many drugs are concomitantly administered via magnetic resonance imaging (MRI).

A) True

B) False

Answer: A

In metronidazole-induced neurotoxicity, particularly in patients taking higher doses, MRI may show bilateral symmetric T2 hyperintense lesions, and this can be further confirmed by their resolution after stopping the drug. Central metronidazole symptoms are seizures, dizziness, vertigo, ataxia, encephalopathy, irritability, weakness, insomnia, headache, and tremors.

Metronidazole is also commonly associated with peripheral neuropathy, which resolves after cessation of the drug. 

#pharmacology

#neurology

#radiology

References:

1. Patel L, Batchala P, Almardawi R, Morales R, Raghavan P. Acute metronidazole-induced neurotoxicity: an update on MRI findings. Clin Radiol. 2020 Mar;75(3):202-208. doi: 10.1016/j.crad.2019.11.002. Epub 2019 Dec 16. PMID: 31858989.

2. Lefkowitz A, Shadowitz S. Reversible cerebellar neurotoxicity induced by metronidazole. CMAJ 2018; 190:E961.

3. Daneman N, Cheng Y, Gomes T, et al. Metronidazole-associated Neurologic Events: A Nested Case-control Study. Clin Infect Dis 2021; 72:2095.

spleen size

Q: The size of the spleen correlates with a person's height, weight, and sex.

A) True

B) False

Answer: A

Spleen size correlates with a person's height, weight, and sex, as it is expected to be larger in taller, bulkier males. 

Clinical significance: Calculated spleen size reduces splenomegaly misdiagnosis and avoids a million-dollar workup in otherwise normal individuals.

Bonus pearl: Radiologically reported splenomegaly in an otherwise normal person or without physical findings is called "scanomegaly"! (reference #4)

#physical-exam

#radiology

References:

1. Schranz T, Klaus J, Kratzer W, et al. A comparison of spleen size measured by ultrasound in a random population sample and a matched sample of patients at a university hospital, and the determination of normal values and influencing factors. Z Gastroenterol 2021; 59:438.

2. Pelizzo G, Guazzotti M, Klersy C, et al. Spleen size evaluation in children: Time to define splenomegaly for pediatric surgeons and pediatricians. PLoS One 2018; 13:e0202741.

3. Tsehay B, Shitie D, Afenigus A, Essa M. Sonographic evaluation of spleen size in apparently healthy children in north-west Ethiopia, 2020: time to define splenomegaly. BMC Pediatr 2021; 21:318.

4. Ntaios G, Chatzinikolaou A. The spleen in beta thalassaemia minor: splenomegaly or just 'scanomegaly'? Br J Haematol. 2008 Oct;143(1):143. doi: 10.1111/j.1365-2141.2008.07306.x. Epub 2008 Jul 28. PMID: 18665837.

SGLT2 inhibitors and diabetes-related foot disease

Q: SGLT2 inhibitors (sodium-glucose cotransporter-2 (SGLT2) inhibitors, also called "flozins" have an extra advantage in patients with active diabetic foot ulcerations by advancing healing.

A) True

B) False

Answer: B

SGLT2 inhibitors should be avoided in the following groups of patients:

• frequent bacterial urinary tract infections (UTIs) 
• genitourinary (GU) yeast infections
• low bone density 
• high risk for falls and fractures
• active foot ulceration
• risks for diabetic ketoacidosis 
• pancreatic insufficiency
• drug or alcohol use disorder
• NPO status

SGLT2 inhibitors, particularly canagliflozin, are associated with an added risk of lower extremity infection and amputation. Diabetic patients with neuropathy, foot deformity, vascular disease, and history of previous foot ulceration should be cautioned and examined frequently if SGLT2 drugs are used.

#endocrine

References: 

1. Halimi S, Vergès B. Adverse effects and safety of SGLT-2 inhibitors. Diabetes Metab. 2014 Dec;40(6 Suppl 1):S28-34. doi: 10.1016/S1262-3636(14)72693-X. PMID: 25554069.

2. Highton P,  & et.al: The use of SGLT2 inhibitors in people with diabetes-related foot disease: A Delphi-based consensus study. Diabetes Obes Metab. 2025 Aug;27(8):4537-4546. doi: 10.1111/dom.16498. Epub 2025 Jun 11. PMID: 40495570; PMCID: PMC12232341.

Etomidate and Seizure

Q: Etomidate is contraindicated in patients with seizure disorders.

A) Yes

B) No

Answer: B

Conventionally, it is believed that etomidate is contraindicated in patients with seizures. This belief came from instances of post-etomidate myoclonus, which occurs in a few patients. Major side effects of etomidate include adrenal suppression, myoclonus, and evidence of regional cerebral excitation (nonclinical, EEG-specific) after intubation. Myoclonus is frequently misidentified as seizure activity. Etomidate is safe to use for the induction of patients with seizures and even in refractory status epilepticus. Postintubation sedation with propofol or a benzodiazepine prevents neuroexcitation.

Etomidate decreases cerebral blood flow and cerebral metabolic oxygen demand while preserving cerebral perfusion pressure.

#neurology

#pharmacology

#procedures

References:

1. Jellish WS, Riche H, Salord F, et al. Etomidate and thiopental-based anesthetic induction: comparisons between different titrated levels of electrophysiologic cortical depression and response to laryngoscopy. J Clin Anesth 1997; 9:36.

2. Oglesby AJ. Should etomidate be the induction agent of choice for rapid sequence intubation in the emergency department? Emerg Med J 2004; 21:655.

3. Reddy RV, Moorthy SS, Dierdorf SF, et al. Excitatory effects and electroencephalographic correlation of etomidate, thiopental, methohexital, and propofol. Anesth Analg 1993; 77:1008.

D-Dimer, PE and crack

Q: 38-year-old male presented to the ED after a "crack" party with acute shortness of breath. Initial CXR is c/w signs of pulmonary infarction. A CT scan was ordered, and the D-dimer was positive. D-dimer is a good test to differentiate pulmonary embolism (PE) from acute "crack lung."

A) True 

B) False

Answer: B

Acute cocaine-induced pulmonary toxicity can cause a false positive D-dimer. No specific laboratory test differentiates the two conditions. History, physical exam, and signs and symptoms play an integral role. This is further compounded by the fact that even toxicology testing for cocaine and its metabolites is not confirmatory, as cocaine is rapidly metabolized and detectable in blood and urine only briefly. 

A specialized test, benzoylecgonine, is the major urinary metabolite of cocaine and can be detected in the blood for two days after cocaine use and in the urine for a few more days. 

#toxicity

#lab-med

References:

1.  Kabrhel C, Mark Courtney D, Camargo CA Jr, Plewa MC, Nordenholz KE, Moore CL, Richman PB, Smithline HA, Beam DM, Kline JA. Factors associated with positive D-dimer results in patients evaluated for pulmonary embolism. Acad Emerg Med. 2010 Jun;17(6):589-97. doi: 10.1111/j.1553-2712.2010.00765.x. PMID: 20624138; PMCID: PMC3538031.

Gadolinium in pregnancy.

Q: A 27-year-old female with a 32-week pregnancy and a past medical history of multiple sclerosis (MS) is admitted with an exacerbation of her MS. MRI with Gadolinium is ordered by a neurology intern.  Intravenous gadolinium-based contrast agent (GBCA) can be safely administered to pregnant patients.

A) True

B) False

Answer: B

Gadolinium may cause an adverse fetal outcome. Use GBCA only if ABSOLUTELY necessary. GBCA in utero is associated with increased rates of neonatal death. It may also be associated with rheumatologic or inflammatory skin conditions through age 4.

#pharmacology

#neurology

#radiology

#ob-gyn

References:

1. Ray JG, Vermeulen MJ, Bharatha A, et al. Association Between MRI Exposure During Pregnancy and Fetal and Childhood Outcomes. JAMA 2016; 316:952.

2. Alghamdi SA Sr. Gadolinium-Based Contrast Agents in Pregnant Women: A Literature Review of MRI Safety. Cureus. 2023 May 3;15(5):e38493. doi: 10.7759/cureus.38493. PMID: 37273372; PMCID: PMC10237509.

3. Coyte RM, Darrah T, Olesik J, Barrett E, O'Connor TG, Brunner J, Love T, Perez-D'Gregorio R, Wang HZ, Aleksunes LM, Buckley B, Doherty C, Miller RK. Gadolinium during human pregnancy following administration of gadolinium chelate before pregnancy. Birth Defects Res. 2023 Aug 15;115(14):1264-1273. doi: 10.1002/bdr2.2209. Epub 2023 Jun 19. PMID: 37334869; PMCID: PMC11784526.

An ENT case!

Q: 55 years old male originally from Tunisia without any past medical history is admitted to the ICU with severe otitis media and marked epistaxis. On clinical exam, a neck mass is noted. What is the probable diagnosis?

Answer: Nasopharyngeal carcinoma 

The objective of this question is to describe the classic triad of nasopharyngeal carcinoma, which consists of

• neck mass
• nasal obstruction with epistaxis
• serous otitis media

Other clinical features include headache, diplopia, and facial numbness, which occur due to cranial nerve involvement. A neck mass is cervical node metastasis. Any middle-aged patient, particularly a male with classically no past medical history of otitis media, should raise suspicion for nasopharyngeal carcinoma. The origin of the patient's culture and birth is also very important in making the diagnosis; the patient in the above question is from Tunisia (or neighboring Algeria and Morocco), where food is many times cooked in rancid butter and/or sheep's fat, containing butyric acid, which is a potential EBV activator and a causative agent for nasopharyngeal carcinoma.

The most endemic area is Southern China, including Hong Kong. Other high-risk areas are Southeast Asia, North Africa, the Middle East, and the Arctic. The risk remain high despite the (im)migration and takes few generations to subside with change in diet. In some of these cultures, feeding salted fish to children is common and considered a risk factor.

#oncology

#ENT

References:

1. Chang ET, Adami HO. The enigmatic epidemiology of nasopharyngeal carcinoma. Cancer Epidemiol Biomarkers Prev 2006; 15:1765.

2. Chua ML, Wee JT, Hui EP, Chan AT. Nasopharyngeal carcinoma. Lancet 2016; 387:1012.

3. Wen Y, Xu Y, Du Y, Zhan Y, Fan S. Nasopharyngeal carcinoma: epidemiology, risk factors, signaling pathways, clinical features, diagnosis, and management. Mol Biomed. 2026 Sep 17;7(1):175. doi: 10.1186/s43556-026-00590-6. PMID: 42752793; PMCID: PMC13586136.

Colonoscopy prep

Q: It is required to prepare patients treated with 4L of polyethylene glycol for colonoscopy for the optimum view.

A) True

B) False

Answer: B

Evidence shows that patients who consume a low-residue diet or clear liquids for at least 24 hours before colonoscopy, rather than 4 L of polyethylene glycol, have no difference in preparation quality. A low-residue diet is low in fiber*. This means avoiding high-fiber foods, such as fruits, vegetables, and whole grains. Clear liquids include water, clear broth, coffee or black tea (no milk), ice, gelatin, and fruit juices without red pigments, as they can be mistaken for blood or can obscure mucosal viewing.

Some experts recommend a cautious approach with a low-residue diet for three days before colonoscopy, with only clear liquids the day before. Also, per American Society of Anesthesiologists (ASA) guidelines, patients should fast for a minimum of two hours after ingestion of clear liquids and six hours after ingestion of light meals before sedation is administered.

*Advise to refer to credible lists from societies/organizations

#GI

#procedures

References:

1. Scaglione G, Oliviero G, Labianca O, et al. One-Day versus Three-Day Low-Residue Diet and Bowel Preparation Quality before Colonoscopy: A Multicenter, Randomized, Controlled Trial. Dig Dis 2023; 41:708.

2. Park DI, Park SH, Lee SK, et al. Efficacy of prepackaged, low residual test meals with 4L polyethylene glycol versus a clear liquid diet with 4L polyethylene glycol bowel preparation: a randomized trial. J Gastroenterol Hepatol 2009; 24:988.

3. Sipe BW, Fischer M, Baluyut AR, et al. 726 Effect of low residual diet on colonoscopy bowel preparation. Gastrointest Endosc 2012; 75:AB163.

4. Practice Guidelines for Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration: Application to Healthy Patients Undergoing Elective Procedures: An Updated Report by the American Society of Anesthesiologists Task Force on Preoperative Fasting and the Use of Pharmacologic Agents to Reduce the Risk of Pulmonary Aspiration. Anesthesiology 2017; 126:376.

Classic neurologic triad of early disseminated Lyme disease

Q: What is the classic neurologic triad of early disseminated Lyme disease?

Answer: Although it may not always present as a triad, in classic cases, the triad consists of:

• meningitis
• cranial neuropathy
• motor or sensory radiculoneuropathy

The common neurologic features of early disseminated Lyme disease may include one or all of:

• Lymphocytic meningitis
• Unilateral or bilateral* cranial nerve palsies (mostly facial nerve)
• Radiculopathy
• Peripheral neuropathy
• Mononeuropathy multiplex
• Cerebellar ataxia 
• Encephalomyelitis 

Although the facial nerve is the most commonly affected cranial nerve, other nerves such as the abducens nerve may be involved.

*Lyme disease is one of the few causes of bilateral cranial nerve palsies, along with tuberculosis, sarcoidosis, and trauma. 

#neurology

References:

1. Halperin JJ. Nervous system Lyme disease. Infect Dis Clin North Am 2008; 22:261.

2. Sauer A, Hansmann Y, Jaulhac B, et al. Five cases of paralytic strabismus as a rare feature of lyme disease. Clin Infect Dis 2009; 48:756.

3. Lantos PM, Rumbaugh J, Bockenstedt LK, et al. Clinical Practice Guidelines by the Infectious Diseases Society of America (IDSA), American Academy of Neurology (AAN), and American College of Rheumatology (ACR): 2020 Guidelines for the Prevention, Diagnosis and Treatment of Lyme Disease. Clin Infect Dis 2021; 72:e1.

PSA level and Acetaminophen

Q: Regular use of acetaminophen may cause falsely ____________ level of Prostate Specific Antigen (PSA). - Select one

A) elevated

B) lowered

Answer: B

Although it is known that a regular intake of 5-alpha-reductase inhibitors (like finasteride and dutasteride) decreases PSA by almost 50 percent, it is less known that regular use of NSAIDs and acetaminophen can also give lower PSA levels when compared with men not taking these drugs. This correlation is time-dependent, meaning longer duration of use may cause even lower PSA values, particularly in patients who are habitual users of NSAIDs, possibly due to the anti-inflammatory properties of these drugs.

Similarly, statin or thiazide use for over a year may lower PSA levels.

Either adjust PSA levels in these patients or interpret them with more caution.

#Urology

#pharmacology

References:

1.Etzioni RD, Howlader N, Shaw PA, et al. Long-term effects of finasteride on prostate specific antigen levels: results from the prostate cancer prevention trial. J Urol 2005; 174:877.

2. Singer EA, Palapattu GS, van Wijngaarden E. Prostate-specific antigen levels in relation to consumption of nonsteroidal anti-inflammatory drugs and acetaminophen: results from the 2001-2002 National Health and Nutrition Examination Survey. Cancer 2008; 113:2053.

3. Chang SL, Harshman LC, Presti JC Jr. Impact of common medications on serum total prostate-specific antigen levels: analysis of the National Health and Nutrition Examination Survey. J Clin Oncol 2010; 28:3951

Danger triangle of face

Q: 72-year-old patient who is intubated for a week due to severe ARDS after community-acquired pneumonia, noted to have an abscess of 2 x 3 cm at the nasal fold. The abscess appears slightly deep but is hard to ascertain. On slight palpation, it appears fluid-filled. Your next action?

A) Do needle aspiration

B) Do incision and drainage

C) Consult ENT

D) Observe

Answer: C

This question emphasizes the importance of infections and abscesses in the central triangle of the face (corners of the mouth and the nasal bridge). This area is popularly known as the "Danger Triangle of the Face" as it carries a high risk of septic phlebitis and intracranial extension through the cavernous sinus. 

Radiological workup to assess depth and evaluation by an ENT service are recommended instead of blind bedside incision and drainage. Usually, superficial abscesses can be managed with warm compresses and broad-spectrum antibiotics. However, early investigation is warranted to avoid major complications.

#ID

#ENT

References:

1. Pannu AK, Saroch A, Sharma N. Danger Triangle of Face and Septic Cavernous Sinus Thrombosis. J Emerg Med. 2017 Jul;53(1):137-138. doi: 10.1016/j.jemermed.2017.03.016. Epub 2017 Apr 10. PMID: 28408235.

2. Battistin U, Hallak YO, Hallak F, Hallak O, AlKhani R. Subacute Cavernous Sinus Thrombosis following a Dental Procedure: Case Report and Review of the Literature. Clin Neurol Neurosurg. 2020 Oct;197:106135. doi: 10.1016/j.clineuro.2020.106135. Epub 2020 Aug 16. PMID: 32836064.

3. Thong JK, Ho BJW, Lim EH, Singh S. A Rare Case of an Isolated Nasal Floor Abscess in an Immunocompetent Patient. Cureus. 2025 Nov 24;17(11):e97694. doi: 10.7759/cureus.97694. PMID: 41450431; PMCID: PMC12737980.

Water Hammer effect

Q: What is the "water hammer" effect in blunt aortic injury (BAI) during Motor Vehicle Accidents (MVA)?

Answer: The mechanism revolves around the isthmus

To understand "water hammer" in BAI, it helps to understand the role of the isthmus between the ascending and descending thoracic aorta as a "transition zone." The ascending aorta is more mobile, and as it transits around the isthmus, it becomes relatively fixed as the descending thoracic aorta. Because the isthmus is intrinsically weaker than the rest of the aorta, it stretches with rapid deceleration. For this reason, most BAIs occur at the aortic isthmus just distal to the (left) subclavian artery.

"Water hammer" effect: In MVA, compression of the abdomen secondary to sudden impact occludes the aorta and leads to rupture of the proximal, intrinsically weak isthmus. This phenomenon explains the correlation of geographically distant diaphragmatic rupture and BAI. This effect was first described more than six decades ago.

#trauma

#CVS

References:

Nikolic S, Atanasijevic T, Mihailovic Z, et al. Mechanisms of aortic blunt rupture in fatally injured front-seat passengers in frontal car collisions: an autopsy study. Am J Forensic Med Pathol 2006; 27:292.

LUNDERVALL J. THE MECHANISM OF TRAUMATIC RUPTURE OF THE AORTA. Acta Pathol Microbiol Scand 1964; 62:34.

Rizoli SB, Brenneman FD, Boulanger BR, Maggisano R. Blunt diaphragmatic and thoracic aortic rupture: an emerging injury complex. Ann Thorac Surg 1994; 58:1404.

Richens D, Field M, Neale M, Oakley C. The mechanism of injury in blunt traumatic rupture of the aorta. Eur J Cardiothorac Surg 2002; 21:288.

Night sweats associated with a strong, peculiar, moldy odor

Q: Which Infectious Disease (ID) may present with night sweats associated with a strong, peculiar, moldy odor?

Answer: Brucellosis

Although Brucellosis has many symptoms, it is hard to distinguish from other ID symptoms, such as fever, malaise, night sweats, arthralgias, weight loss, low back pain, headache, dizziness, anorexia, dyspepsia, abdominal pain, cough, and depression, and possibly hepatomegaly, splenomegaly, and/or lymphadenopathy, but the association of night sweats with a strong, peculiar, moldy (or musty) odor is characteristic of Brucellosis.

A couple of good reviews on Brucellosis can be found in the references below.

#ID

References:

1. Qureshi KA, Parvez A, Fahmy NA, Abdel Hady BH, Kumar S, Ganguly A, Atiya A, Elhassan GO, Alfadly SO, Parkkila S, Aspatwar A. Brucellosis: epidemiology, pathogenesis, diagnosis and treatment-a comprehensive review. Ann Med. 2023;55(2):2295398. doi: 10.1080/07853890.2023.2295398. Epub 2024 Jan 2. PMID: 38165919; PMCID: PMC10769134.

2. Khairullah AR, Kurniawan SC, Puspitasari Y, Aryaloka S, Silaen OSM, Yanestria SM, Widodo A, Moses IB, Effendi MH, Afnani DA, Ramandinianto SC, Hasib A, Riwu KHP. Brucellosis: Unveiling the complexities of a pervasive zoonotic disease and its global impacts. Open Vet J. 2024 May;14(5):1081-1097. doi: 10.5455/OVJ.2024.v14.i5.1. Epub 2024 May 31. PMID: 38938422; PMCID: PMC11199761.

3. Alavi SM, Alavi L. Treatment of brucellosis: a systematic review of studies in recent twenty years. Caspian J Intern Med. 2013 Spring;4(2):636-41. PMID: 24009951; PMCID: PMC3755828.

"Paradoxical hypokalemia"

Q: "Paradoxical hypokalemia" is more common in? - Select one

A) Hereditary hypokalemic periodic paralysis

B) Thyrotoxic hypokalemic periodic paralysis

Answer: B

Many patients with thyrotoxic periodic paralysis may develop worsening, "paradoxical" hypokalemia after potassium repletion. This phenomenon may even occur in the nonperiodic phase whenever potassium is repleted. The underlying pathophysiologic mechanism is increased thyroxine concentration, which causes exaggerated potassium uptake.

Interestingly, the treatment is further potassium repletion. Usually, the drop is around 0.4 mEq/L, which can be life-threatening in view of already critical hypokalemia in these patients. Unfortunately, these patients are prone to develop hyperkalemia after repletion.

The differential diagnosis is based on urinary potassium excretion rates. Patients with hereditary hypokalemic periodic paralysis have a low urinary excretion of potassium, while patients with paradoxical hypokalemia have higher urinary potassium excretion rates, higher renin levels, and require higher volumes of saline resuscitation.

#electrolytes

# nephrology

#neurology

References:

1. Shiang JC, Cheng CJ, Tsai MK, et al. Therapeutic analysis in Chinese patients with thyrotoxic periodic paralysis over 6 years. Eur J Endocrinol 2009; 161:911.

2. Sung CC, Cheng CJ, Chiang WF, et al. Etiologic and therapeutic analysis in patients with hypokalemic nonperiodic paralysis. Am J Med 2015; 128:289.

3. 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.

4. Holm-Yildiz S, Krag T, Witting N, Pedersen BS, Dysgaard T, Sloth L, Pedersen J, Kjær R, Kannuberg L, Dahlqvist J, de Stricker Borch J, Solheim T, Fornander F, Eisum AS, Vissing J. Hypokalemic periodic paralysis: a 3-year follow-up study. J Neurol. 2023 Dec;270(12):6057-6063. doi: 10.1007/s00415-023-11964-z. Epub 2023 Sep 1. PMID: 37656291; PMCID: PMC10632268.