Risks of HIT

Q: Which of the following patients has the highest risk of Heparin-Induced Thrombocytopenia (HIT)? - select one

A) Medical patients receiving Low Molecular Weight (LMW) heparin

B) Obstetric patients receiving Unfractionated Heparin (UFH)

C) Major surgery patients receiving LMW heparin

Answer: C

Although not written on the stone, usually patients receiving Heparin - either UF or LMW - are divided into three categories for the risk of developing HIT.

Low (less than 0.1%)

• Medical or obstetric patients receiving LMW heparin
• Minor surgery or minor trauma patients receiving LMW heparin
• Patients receiving fondaparinux or an anticoagulant not associated with the development of HIT

Intermediate (less than 0.1 to 1%)

• Medical or obstetric patients receiving UFH
• Major surgery or major trauma patients receiving LMW heparin

High (more than 1%)

• Major surgery or major trauma patients receiving UFH

- Low-risk patients do not require monitoring.

- Intermediate and high-risk patients require monitoring every 2-3 days from day 0 to day 14

Also, the risk of HIT is higher for therapeutic dose UFH than for lower doses, which include heparin flushes.

#hematology

#pharmacology

References:

1. Cuker A, Arepally GM, Chong BH, et al. American Society of Hematology 2018 guidelines for management of venous thromboembolism: heparin-induced thrombocytopenia. Blood Advances 2018; 2:3360.

2. Hogan M, Berger JS. Heparin-induced thrombocytopenia (HIT): Review of incidence, diagnosis, and management. Vasc Med. 2020 Apr;25(2):160-173. doi: 10.1177/1358863X19898253. Epub 2020 Mar 20. PMID: 32195628.

Oxygen delivery (DO2) and consumption (VO2) graph

Q: Why does it help to read the Oxygen delivery (DO2) and consumption (VO2) graph in reverse?

Answer: It helps a lot more if the following graph is read from right to left!

In the normal healthy state (of oxygenation balance), oxygen consumption remains constant over a range of DO2, and decreases only when DO2 falls below a critical level, called critical DO2. 

Pathologic changes caused by any condition, such as sepsis or systemic inflammatory responses, cause increased VO2 and subsequently impaired peripheral oxygen utilization, resulting in a pathologic (or earlier) critical DO2.

The following graph illustrates the same concept in various pathological diseases, either alone or in combination, such as anemia, heart failure, or Multi-Organ Dysfunction Syndrome (MODS).

#oxygen-delivery

#hemodynamics

References:

1. Wolff CB. Normal cardiac output, oxygen delivery and oxygen extraction. Adv Exp Med Biol. 2007;599:169-82. doi: 10.1007/978-0-387-71764-7_23. PMID: 17727262.

2. Cain SM. Acute lung injury. Assessment of tissue oxygenation. Crit Care Clin 1986; 2:537.

AF Burden

Q: How do you define Atrial Fibrillation (AF) burden?

Answer: There is no consensus definition, but AF burden is usually described as the "percentage of time in AF during a monitoring period".

Clinical significance: The duration of the most extended recorded episode of AF is considered an additional risk factor of AF associated with thromboembolic risk.

It is a relatively new concept that has gained significance over the last couple of years. The author of this question encourages readers to review the following references from the existing literature.

#cardiology

References:

1. Becher N, Metzner A, Toennis T, Kirchhof P, Schnabel RB. Atrial fibrillation burden: a new outcome predictor and therapeutic target. Eur Heart J. 2024 Aug 16;45(31):2824-2838. doi: 10.1093/eurheartj/ehae373. PMID: 38953776; PMCID: PMC11328870.

2. Doehner W, Boriani G, Potpara T, Blomstrom-Lundqvist C, Passman R, Sposato LA, Dobrev D, Freedman B, Van Gelder IC, Glotzer TV, Healey JS, Karapanayiotides T, Lip GYH, Merino JL, Ntaios G, Schnabel RB, Svendsen JH, Svennberg E, Wachter R, Haeusler KG, Camm AJ. Atrial fibrillation burden in clinical practice, research, and technology development: a clinical consensus statement of the European Society of Cardiology Council on Stroke and the European Heart Rhythm Association. Europace. 2025 Mar 5;27(3):euaf019. doi: 10.1093/europace/euaf019. PMID: 40073206; PMCID: PMC11901050.

3. AlTurki A, Essebag V. Atrial Fibrillation Burden: Impact on Stroke Risk and Beyond. Medicina (Kaunas). 2024 Mar 26;60(4):536. doi: 10.3390/medicina60040536. PMID: 38674182; PMCID: PMC11051719.

4. Doundoulakis I, Nedios S, Zafeiropoulos S, Vitolo M, Della Rocca DG, Kordalis A, Shamloo AS, Koliastasis L, Marcon L, Chiotis S, Sorgente A, Soulaidopoulos S, Imberti JF, Botis M, Pannone L, Gatzoulis KA, Sarkozy A, Stavrakis S, Boriani G, Boveda S, Tsiachris D, Chierchia GB, de Asmundis C. Atrial fibrillation burden: Stepping beyond the categorical characterization. Heart Rhythm. 2025 May;22(5):1179-1187. doi: 10.1016/j.hrthm.2024.08.051. Epub 2024 Aug 27. PMID: 39197738.

Propofol and airway resistance

Q: Propofol _______________ airway resistance. - Select one

A) decreases

B) increases

Answer: A

Propofol is one of the most commonly used drugs in ICUs, providing sedation as well as amnesia, but NOT analgesia. It has a quick effect of approximately 15 to 45 seconds, and a short duration of action of 5 to 10 minutes. 

Propofol reduces airway resistance, making it an attractive induction agent for intubation in patients with bronchospasm. Also, it does not prolong the QT interval.

Propofol's other effects are due to suppression of sympathetic activity, which also may cause myocardial depression and peripheral vasodilation.

#pharmacology

#procedures

References:

1. Eames WO, Rooke GA, Wu RS, Bishop MJ. Comparison of the effects of etomidate, propofol, and thiopental on respiratory resistance after tracheal intubation. Anesthesiology 1996; 84:1307.

2. Conti G, Ferretti A, Tellan G, et al. Propofol induces bronchodilation in a patient mechanically ventilated for status asthmaticus. Intensive Care Med 1993; 19:305.

3. Pizov R, Brown RH, Weiss YS, et al. Wheezing during induction of general anesthesia in patients with and without asthma. A randomized, blinded trial. Anesthesiology 1995; 82:1111.

Splenic conditioning

Q: What is "splenic conditioning" in Red Blood Cells (RBCs) circulation?

Answer: After splenectomy, there is a surge of variable target cells, acanthocytes, and other RBC changes, particularly Howell-Jolly bodies, which are nuclear fragments.

The spleen is responsible for removing excess membrane from RBCs. This process is known as "splenic conditioning." The exact mechanism is not well understood, although the reduction in RBC lipid content suggests that processes involving lipases are involved. 

In the first few weeks after splenectomy, target cells count for 2 to 10 percent of all circulating RBCs. These cells have an increased membrane, a higher surface-to-volume ratio, and reduced osmotic fragility. These RBCs eventually lose their excess lipid by conditioning at other sites and the gradual disappearance of target cells.

#hematology

#physiology

References:

1. de Haan LD, Werre JM, Ruben AM, et al. Alterations in size, shape and osmotic behaviour of red cells after splenectomy: a study of their age dependence. Br J Haematol 1988; 69:71.

2. Singer K, Weisz L. The life cycle of the erythrocyte after splenectomy and the problems of splenic hemolysis and target cell formation. Am J Med Sci 1945; 210:301.

3. Singer K, Miller EB, et al. Hematologic changes following splenectomy in man, with particular reference to target cells, hemolytic index, and lysolecithin. Am J Med Sci 1941; 202:171.

HEV in pregnancy

Q: Hepatitis E virus (HEV) infection is most life-threatening in pregnancy when it occurs in? - select one

A) First trimester

B) Second trimester

C) Third trimester

Answer: C

HEV infection in pregnancy is unusually associated with high mortality up to 25 percent. Pregnant patients are more prone to developing acute hepatic failure if they contract HEV. Liver failure is more common during the third trimester of pregnancy. Fortunately, in endemic areas, if a female child is exposed to HEV early in life, it reduces the risk of acute liver failure in pregnancy if re-infected later in life.

In endemic countries, poor nutritional status and lack of access to medical care also play a part in this high mortality.

#hepatology

#Ob-gyn

#ID

References:

1. Khuroo MS, Teli MR, Skidmore S, et al. Incidence and severity of viral hepatitis in pregnancy. Am J Med 1981; 70:252.

2. Patra S, Kumar A, Trivedi SS, et al. Maternal and fetal outcomes in pregnant women with acute hepatitis E virus infection. Ann Intern Med 2007; 147:28.

3. Navaneethan U, Al Mohajer M, Shata MT. Hepatitis E and pregnancy: understanding the pathogenesis. Liver Int 2008; 28:1190.

highest rate of having MDR P. aeruginosa site

Q: Which of the following has the highest chances of having MDR P. aeruginosa? - select one

A) Ventilator-associated pneumonia (VAP)

B) Central line-associated bloodstream infection (CLABSI)

C) Catheter-associated urinary tract infection (CAUTI)

D) Surgical site infection (SSI)

Answer: A

VAPs continue to be the leading cause of MDR among P. aeruginosa, with a rate of about 15.4 percent.

In ICUs, CLABSI was reported in 14.2 percent of cases, and CAUTIs in 8.7 percent of cases. Surgical site infections occur in approximately 4 percent of cases.

#ID

Reference:

HAI Pathogens and Antimicrobial Resistance Report 2018-2021. Centers for Disease Control and Prevention, 2023. Available at: https://www.cdc.gov/nhsn/hai-report/index.html (last accessed on September 20, 2025).

Revised Baux Score

Q: What is the significance of the Revised Baux Score (rBaux) in burn patients?

Answer: It provides a good prediction of mortality.

The Revised Baux Score (rBaux) is a formula: 

Age + %TBSA (Total Body Surface Area) Burned + (17 x R)

 - where R is 1 if there is an inhalation injury and 0 if there is none.

Two Examples:

1. For a 40-year-old patient with a 30% TBSA burn and an inhalation injury:

40 (Age) + 30 (%TBSA) + (17 x 1) = 87

2. For the same patient without an inhalation injury: 

40 (Age) + 30 (%TBSA) + (17 x 0) = 70

Numerous online calculators are available through search engines.

In recent years, diabetes has also been suggested as a factor in predicting mortality in burn patients (see reference # 4).

#burn

References:

1. Osler T, Glance LG, Hosmer DW. Simplified estimates of the probability of death after burn injuries: extending and updating the baux score. J Trauma 2010; 68:690.

2. Edgar MC, Bond SM, Jiang SH, Scharf IM, Bejarano G, Vrouwe SQ. The Revised Baux Score as a Predictor of Burn Mortality: A Systematic Review and Meta-Analysis. J Burn Care Res. 2023 Nov 2;44(6):1278-1288. doi: 10.1093/jbcr/irad075. PMID: 37220881.

3. Baraka SM, Kiswezi A, Olasinde AA, Edyedu I, Molen SF, Muhumuza J, Zawadi GV, Okedi FX. Role of the revised Baux score in predicting mortality among burn patients in an African low-income country: a multicentre prospective cohort. Ann Med Surg (Lond). 2024 Jan 30;86(8):4364-4367. doi: 10.1097/MS9.0000000000001774. PMID: 39118688; PMCID: PMC11305736.

4. Nehila T, Mikhael M, Arora S, Jupudi R, Criscione JX, Le NK, Whalen K, Buller K, Troy J, Laun J. 504 Revised Baux Score Identifies a New Risk Factor for Mortality: History of Diabetes. J Burn Care Res. 2024 Apr 17;45(Suppl 1):114. doi: 10.1093/jbcr/irae036.139. PMCID: PMC11023089.

Cancer sidedness in CRC

Q: Left-sided primary Colorectal Cancer (CRC) is associated with a significantly reduced risk of death.

A) True

B) False

Answer: A

Primary tumor location is one of the essential prognostic factors in Colorectal Cancer (CRC). Left-sided primary tumor location (at or beyond the splenic flexure) is found to be associated with a significantly reduced risk of death. This mortality benefit is independent of any variable such as stage, race, use of adjuvant chemotherapy, year of study, and quality of the included studies!

This advantage is attributed to different kinds of gene mutations. "Cancer sidedness" is also considered a predictive factor for response to therapies.

#oncology

References:

1. Holch JW, Ricard I, Stintzing S, et al. The relevance of primary tumour location in patients with metastatic colorectal cancer: A meta-analysis of first-line clinical trials. Eur J Cancer 2017; 70:87.

2. Petrelli F, Tomasello G, Borgonovo K, et al. Prognostic Survival Associated With Left-Sided vs Right-Sided Colon Cancer: A Systematic Review and Meta-analysis. JAMA Oncol 2016; 3:211.

3. Tejpar S, Stintzing S, Ciardiello F, et al. Prognostic and Predictive Relevance of Primary Tumor Location in Patients With RAS Wild-Type Metastatic Colorectal Cancer: Retrospective Analyses of the CRYSTAL and FIRE-3 Trials. JAMA Oncol 2016.

4. Loree JM, Pereira AAL, Lam M, et al. Classifying Colorectal Cancer by Tumor Location Rather than Sidedness Highlights a Continuum in Mutation Profiles and Consensus Molecular Subtypes. Clin Cancer Res 2018; 24:1062.

CT scan findings on bronchiectasis

Q: What are the three reliable signs of bronchiectasis on a CT scan?

Answer: Although the presence of clinical symptoms is of paramount importance in bronchiectasis, such as daily cough and sputum, with frequent exacerbations, three reliable features to diagnose bronchiectasis on a CT scan are:

• Airway-to-arterial ratio ≥1.5 (internal airway lumen diameter/adjacent pulmonary artery diameter)
• Lack of tapering of bronchi (tram track appearance)
• Airway visibility within 1 cm of a costal pleural surface or touching the mediastinal pleura

#pulmonary

#radiology

References;

1. Aliberti S, Goeminne PC, O'Donnell AE, et al. Criteria and definitions for the radiological and clinical diagnosis of bronchiectasis in adults for use in clinical trials: international consensus recommendations. Lancet Respir Med 2022; 10:298.

2. Hill AT, Sullivan AL, Chalmers JD, et al. British Thoracic Society Guideline for bronchiectasis in adults. Thorax 2019; 74:1.

Uremia and coagulopathy

Q: Uremia prolongs? select one

A) PT

B) PTT

C) PT and PTT

D) Bleeding Time (BT)

E) PT, PTT, and BT

Answer: D

Uremia is unique in the sense that it doesn't affect PT or PTT. DDAVP is the first-line treatment, which acts promptly but has a short duration of action of a few hours and exhibits tachyphylaxis. 

Conjugated estrogens have also shown promise, but their onset of action is slower (approximately 6 hours), and the effect lasts for about 2 weeks.

#hematology

#lab-medicine

References:

1. Molino D, De Lucia D, Gaspare De Santo N. Coagulation disorders in uremia. Semin Nephrol. 2006 Jan;26(1):46-51. doi: 10.1016/j.semnephrol.2005.06.011. PMID: 16412826.

2. Brophy DF, Martin EJ, Carr SL, Kirschbaum B, Carr ME Jr. The effect of uremia on platelet contractile force, clot elastic modulus and bleeding time in hemodialysis patients. Thromb Res. 2007;119(6):723-9. doi: 10.1016/j.thromres.2006.02.013. Epub 2006 Jun 21. PMID: 16793120.

SRC - risk factors

Q: Maintenance of high-dose steroid therapy in scleroderma patients prevents Scleroderma Renal Crisis (SRC).

A) True

B) False

Answer: B

The use of glucocorticoids, particularly high doses, may lead to SRC. High-dose glucocorticoid causes salt and volume retention, the causation or worsening of hypertension, and so become a precursor of SRC.

Other major clinical risk factors are 

• contractures of large joints
• new-onset anemia
• new heart failure 
• development of pericardial effusion 

#rheumatology

#nephrology

References:

1. Kohno K, Katayama T, Majima K, et al. A case of normotensive scleroderma renal crisis after high-dose methylprednisolone treatment. Clin Nephrol 2000; 53:479.

2. Steen VD, Medsger TA Jr. Case-control study of corticosteroids and other drugs that either precipitate or protect from the development of scleroderma renal crisis. Arthritis Rheum 1998; 41:1613.

3. Steen VD, Medsger TA Jr, Osial TA Jr, et al. Factors predicting development of renal involvement in progressive systemic sclerosis. Am J Med 1984; 76:779.

4. Gordon SM, Stitt RS, Nee R, et al. Risk Factors for Future Scleroderma Renal Crisis at Systemic Sclerosis Diagnosis. J Rheumatol 2019; 46:85.

preparing isotonic solution

Q: Which of the solutions will produce a nearly isotonic solution? - select one

A) 3 amps of NaHCO3 in 1 L of D-5 W

B) 3 amps of NaHCO3 in 1 L of 0.45 NS

Answer: A

Adding three ampules of sodium bicarbonate, each containing 50 mEq of sodium and 50 mL of water, to one liter of 5% dextrose in water, produces a nearly isotonic solution with a sodium concentration of approximately 130 mEq/L. 

Adding the same three ampules of sodium bicarbonate to one liter of half isotonic saline (0.45%), which contains about 77 mEq/L of sodium, will produce a highly hypertonic solution with a sodium concentration of 197 mEq/L!

The objective of this question is to enhance the understanding that a simple mistake in an order can be fatal!

#electrolytes

#acidosis

Further readings:

1. Adeva-Andany MM, Fernández-Fernández C, Mouriño-Bayolo D, Castro-Quintela E, Domínguez-Montero A. Sodium bicarbonate therapy in patients with metabolic acidosis. ScientificWorldJournal. 2014;2014:627673. doi: 10.1155/2014/627673. Epub 2014 Oct 21. PMID: 25405229; PMCID: PMC4227445.

2. Zhang Z, Zhu C, Mo L, Hong Y. Effectiveness of sodium bicarbonate infusion on mortality in septic patients with metabolic acidosis. Intensive Care Med. 2018 Nov;44(11):1888-1895. doi: 10.1007/s00134-018-5379-2. Epub 2018 Sep 25. PMID: 30255318.

3. Sepúlveda RA, Juanet C, Sharp J, Kattan E. Bicarbonato de sodio intravenoso ¿Cuándo, cómo y por qué utilizarlo? [Intravenous sodium bicarbonate. When, how and why to use it?]. Rev Med Chil. 2022 Sep;150(9):1214-1223. Spanish. doi: 10.4067/S0034-98872022000901214. PMID: 37358132.

Picture Diagnosis

Q 34 years old male presented to the ED after hours of partying at a local bar, where he started puking due to a large intake of alcohol. CXR on arrival is below.

Answer: The V-sign of Naclerio

The V-sign of Naclerio (see Arrows in the picture above) is present in approximately one-fourth of patients with esophageal perforation. These are radiolucent streaks of air that dissect the fascial planes behind the heart to form the shape of the letter V. It is a relatively specific radiographic sign of esophageal perforation.

Decades ago, when CXR was a luxury in ED, this was considered an early sign of esophageal rupture (see reference # 2).

#GI

#surgical-critical-care

References:

1. Komaru Y, Maeda A. Naclerio's V sign and continuous diaphragm sign after endoscopy. BMJ Case Rep. 2018 Sep 21;2018:bcr2018226021. doi: 10.1136/bcr-2018-226021. PMID: 30244226; PMCID: PMC6157589.

2. NACLERIO EA. The V sign in the diagnosis of spontaneous rupture of the esophagus (an early roentgen clue). Am J Surg. 1957 Feb;93(2):291-8. doi: 10.1016/0002-9610(57)90781-x. PMID: 13394807.

Burton line

Q: 62 years male who has worked at a shooting range his entire life is admitted to the ICU with accelerated hypertension. Patient on history taking also complains of colicky abdominal pain getting worse over the years, arthralgia, myalgia, fatigue, insomnia, decreased libido, loss of short-term memory, irritability, tremor, and depression. On exam, a Burton line was noted on the gums. CBC is reported with basophilic stippling. Which poisoning is expected?

Answer: Lead

Burton line is a bluish gingival pigmentation at the gum-tooth line. This occurs due to the reaction of lead with bacteria in dental plaque that causes the formation of lead sulfide. If present with other symptoms, it is probably lead toxicity, which can be proven otherwise. 

At shooting ranges, dust generated from the use of leaded bullets and leaching from bullets is a known cause of higher blood lead levels.

#toxicity

References:

1. Helmich F, Lock G. Burton's Line from Chronic Lead Intoxication. N Engl J Med. 2018 Nov 8;379(19):e35. doi: 10.1056/NEJMicm1801693. PMID: 30403939.

2. Karami M, Mohammed LM, Dehghan SF, Hashemi SS, Baiee H. Burton's Line on the Gum Seen in Lead Poisoning Among Petroleum Refinery Workers in Kirkuk City, Iraq: A Case Series. Cureus. 2024 May 10;16(5):e60050. doi: 10.7759/cureus.60050. PMID: 38854344; PMCID: PMC11162749.

3. Morita T, Nishizawa T, Morikawa T. Burton line and basophilic stippling in lead poisoning. CMAJ. 2024 Apr 14;196(14):E487. doi: 10.1503/cmaj.231405. PMID: 38621780; PMCID: PMC11019604.

Glucagon-Airway connection

Case: 44 years old male with a past medical history of hypertension (HTN) but stable on extended-release metoprolol, is brought to the Emergency Department (ED) after developing a severe anaphylactic reaction at a local restaurant. Paramedics administered two doses of intramuscular (IM) epinephrine, but there was little to no relief. Intravenous fluid (IVF) resuscitation started in the field. The ED physician administered Glucagon before administering the third dose of 'epi'. The patient developed severe vomiting and aspiration and required intubation.

Discussion: Rapid IV administration of glucagon may induce severe vomiting and may cause life-threatening aspiration and respiratory failure, particularly if trained staff or a controlled environment is not available. Glucagon should be administered with a slow IV push over 5 minutes, followed by an infusion of 5 to 15 mcg/minute until symptoms are resolved. (Pediatric dosing is different.)

Conventionally, literature has described that patients on beta-blockers, and more so, those who are also taking them in combination with angiotensin-converting enzyme inhibitors, develop more severe anaphylactic reactions, but some recent data failed to sustain that claim. Said that the clinician should stay ready in these patients with all arsenals in hand, as anaphylactic shock does not provide any luxury of time! 

Glucagon provides inotropic and chronotropic effects that are not mediated through beta receptors.

#allergy

#hemodynamics

References:

1. Nassiri M, Babina M, Dölle S, et al. Ramipril and metoprolol intake aggravate human and murine anaphylaxis: evidence for direct mast cell priming. J Allergy Clin Immunol 2015; 135:491.

2. White JL, Greger KC, Lee S, et al. Patients Taking β-Blockers Do Not Require Increased Doses of Epinephrine for Anaphylaxis. J Allergy Clin Immunol Pract 2018; 6:1553.

3. Thomas M, Crawford I. Best evidence topic report. Glucagon infusion in refractory anaphylactic shock in patients on beta-blockers. Emerg Med J 2005; 22:272.

4. Miyashiro D, Abud EM, Cook KA, White AA. Managing anaphylaxis in patients on β-blockers: Case insights and practical considerations. Ann Allergy Asthma Immunol. 2025 Jul 7:S1081-1206(25)00335-7. doi: 10.1016/j.anai.2025.06.031. Epub ahead of print. PMID: 40633724.

Evaluating elevated bilirubin

Q: In conjugated (direct) hyperbilirubinemia, both unconjugated (indirect) and conjugated bilirubin are elevated. 

A) True

B) False

Answer: A

It is rarely appreciated that in conjugated hyperbilirubinemia, there is always some level of unconjugated hyperbilirubinemia.

The causes of conjugated hyperbilirubinemia are:

• hepatocellular disease
• impaired canalicular excretion of bilirubin, and/or 
• biliary obstruction

The causes of unconjugated hyperbilirubinemia are:

• overproduction of bilirubin
• impaired bilirubin uptake by the liver, and/or 
• abnormalities of bilirubin conjugation

#hepatology

#laboratory-medicine

References:

1. Shroff H, Maddur H. Isolated Elevated Bilirubin. Clin Liver Dis (Hoboken). 2020 May 7;15(4):153-156. doi: 10.1002/cld.944. PMID: 32395242; PMCID: PMC7206321.

2. Guerra Ruiz AR, Crespo J, López Martínez RM, Iruzubieta P, Casals Mercadal G, Lalana Garcés M, Lavin B, Morales Ruiz M. Measurement and clinical usefulness of bilirubin in liver disease. Adv Lab Med. 2021 Jul 9;2(3):352-372. doi: 10.1515/almed-2021-0047. PMID: 37362415; PMCID: PMC10197288.

3. VanWagner LB, Green RM. Evaluating elevated bilirubin levels in asymptomatic adults. JAMA. 2015 Feb 3;313(5):516-7. doi: 10.1001/jama.2014.12835. PMID: 25647209; PMCID: PMC4424929.

Amylase and Lipase half lives

Q: Which of the following enzymes has a longer half-life? - select one

A) serum amylase

B) serum lipase

Answer: B

Serum amylase has a shorter half-life than serum lipase. 

Clinical significance: Amylase levels typically normalize within 24 hours of an episode of acute pancreatitis, but lipase levels remain elevated for several days.

#GI

#laboratory-medicine

Further readings:

1. Ismail OZ, Bhayana V. Lipase or amylase for the diagnosis of acute pancreatitis? Clin Biochem. 2017 Dec;50(18):1275-1280. doi: 10.1016/j.clinbiochem.2017.07.003. Epub 2017 Jul 16. PMID: 28720341.

2. Pieper-Bigelow C, Strocchi A, Levitt MD. Where does serum amylase come from and where does it go? Gastroenterol Clin North Am 1990; 19:793.

3. Alyahya B, Alalshaikh A, Altaweel A, Alsaleh G, Alsaeed A, Somily H, Alotaibi T, Alaqeel M, Al Mehlisi A, Abuguyan F, Altuwaijri F, Al Aseri Z. The Prevalence of Simultaneously Ordering Amylase and Lipase for Diagnosing Pancreatitis. Emerg Med Int. 2023 Sep 27;2023:3988278. doi: 10.1155/2023/3988278. PMID: 37811499; PMCID: PMC10551519.

Mackler's Triad

Q: 54 years male with a previous history of alcohol abuse and a perforated duodenal ulcer is admitted via ED with a diagnosis of Mackler's triad. What is Mackler's triad?

Answer: Mackler's triad includes

• lower chest pain
• vomiting
• subcutaneous emphysema

It is a classic presentation of esophageal rupture (Boerhaave's syndrome), but presents only in a few patients (14%).

 

Notably, the triad has also been reported in the absence of esophageal perforation.

 

Tachypnea and abdominal rigidity are typically accompanied by tachycardia, diaphoresis, fever, and hypotension. Unusual clues include hoarseness caused by involvement of the recurrent laryngeal nerve, tracheal shift, distension of the cervical veins, and proptosis.

 

The condition can quickly progress to multi-organ failure.

#GI

References:

1. Loftus IA, Umana EE, Scholtz IP, McElwee D. Mackler's Triad: An Evolving Case of Boerhaave Syndrome in the Emergency Department. Cureus. 2023 Apr 22;15(4):e37978. doi: 10.7759/cureus.37978. PMID: 37223188; PMCID: PMC10202041.

2. Gunawardene A. Mackler's triad in spontaneous pneumomediastinum. ANZ J Surg. 2023 Jan;93(1-2):437. doi: 10.1111/ans.18147. Epub 2023 Jan 20. PMID: 36660864.

3. Rassameehiran S, Klomjit S, Nugent K. Right-sided hydropneumothorax as a presenting symptom of Boerhaave's syndrome (spontaneous esophageal rupture). Proc (Bayl Univ Med Cent). 2015 Jul;28(3):344-6. doi: 10.1080/08998280.2015.11929269. PMID: 26130884; PMCID: PMC4462217.

Position of patient in anaphylaxis with upper airway swelling or bronchospasm

Q: 44 years old patient went into anaphylaxis after receiving ciprofloxacin infusion. Patient developed upper airway swelling and bronchospasm. The next step should be to put the patient in the Trendelenburg position to counter hypotensive shock.

A) True

B) False

Answer: B

Although classic teaching in anaphylaxis is to keep the patient in a flat, semirecumbent position or even the Trendelenburg position to counteract the expected hypotension from anaphylaxis, if there is prominent upper airway swelling or bronchospasm, it is recommended to elevate the patient's head or even make the patient lean forward until the airway can be secured. This positioning helps minimize airway edema due to gravity.

Raising the legs instead of the Trendelenburg position is always preferred.

# anaphylaxis

#hemodynamic

#airway

Further readings:

1. Australasian Society of Clinical Immunology and Allergy guidelines on anaphylaxis -https://www.allergy.org.au/hp/papers/acute-management-of-anaphylaxis-guidelines (last accessed September 2, 2025)

2. Pumphrey RS. Fatal posture in anaphylactic shock. J Allergy Clin Immunol 2003; 112:451.

3. Geerts BF, van den Bergh L, Stijnen T, et al. Comprehensive review: is it better to use the Trendelenburg position or passive leg raising for the initial treatment of hypovolemia? J Clin Anesth 2012; 24:668.

LA in MALA

Q: Metformin-associated lactic acidosis (MALA) usually cause __________ degree of Lactic Acidosis (LA)? - select one

A) Mild

B) Moderate

C) Severe

Answer: C

One of the most striking features, when combined with history, is the extremely high level of LA in MALA, which is unlikely to be seen in other causes of LA. However, clinicians are required to rule out other causes through a thorough history, examination, and proper investigation.

A lactate level of >8 mmol/L is a norm in MALA and can be elevated up to >20 mmol/L.

#acid-base

#toxicology

#pharmacology

References:

1. Friesecke S, Abel P, Roser M, Felix SB, Runge S. Outcome of severe lactic acidosis associated with metformin accumulation. Crit Care. 2010;14(6):R226. doi: 10.1186/cc9376. Epub 2010 Dec 20. PMID: 21171991; PMCID: PMC3220003.

2. Malani KA, Finn A. Metformin-associated lactic acidosis: a serious complication of a common drug. BMJ Case Rep. 2024 Sep 10;17(9):e260592. doi: 10.1136/bcr-2024-260592. PMID: 39256177.

3. See KC. Metformin-associated lactic acidosis: A mini review of pathophysiology, diagnosis and management in critically ill patients. World J Diabetes. 2024 Jun 15;15(6):1178-1186. doi: 10.4239/wjd.v15.i6.1178. PMID: 38983827; PMCID: PMC11229964.

Balloon of PAC

Q: Why is it important to inflate the Balloon of the Pulmonary Artery Catheter (Swan-Ganz Catheter) as soon as it enters the Right Atrium?

Answer: During Pulmonary Artery Catheter insertion, care must be taken to inflate the balloon as soon as the atrial curve is noticed in the monitor, as it helps to avoid endocardial lesion in the tricuspid valve, as well as in the right atrium and ventricle, such as wall perforation.

#procedure

# hemodynamic

Further readings:

1. Ennala S, Melillo CA, Lane JE, Tonelli AR. Effect of pulmonary artery catheter balloon inflation on pulmonary hemodynamics. Cardiovasc Diagn Ther. 2022 Feb;12(1):37-41. doi: 10.21037/cdt-21-515. PMID: 35282667; PMCID: PMC8898684.

 2. Perforation of the Right Ventricle Induced by Pulmonary Artery Catheter at Induction of Anesthesia for the Surgery for Liver Transplantation: A Case Report and Reviewed of Literature, - Case Report Med. 2009; 2009: 650982. Published online 2009 December 31

BB in cirrhosis

Q: Which of the following beta blockers (BB) is recommended as first-line prophylaxis in compensated cirrhosis? - select one

A) Carvedilol

B) Propranolol

Answer: B

Clinicians often fail to understand the difference in the use of BB in cirrhosis.

• For compensated cirrhosis, carvedilol is the first-line prophylaxis. It has been found to have a survival benefit.
• For decompensated cirrhosis, a nonselective beta blocker that does not have anti-alpha 1 adrenergic activity, like nadolol or propranolol, is recommended. 

Carvedilol is not preferred in decompensated cirrhosis because, due to its anti-alpha 1 adrenergic activity, it may drop blood pressure drastically.

BB lowers the portal pressure by reducing portal blood flow, which is accomplished by vasoconstricting the splanchnic circulation. The target heart rate is 55 to 60 beats per minute, in balance with a tolerable mean arterial pressure (MAP).

#hepatology

#pharmacology

References:

1. McDowell HR, Chuah CS, Tripathi D, et al. Carvedilol is associated with improved survival in patients with cirrhosis: a long-term follow-up study. Aliment Pharmacol Ther 2021; 53:531.

2. Shah HA, Azam Z, Rauf J, et al. Carvedilol vs. esophageal variceal band ligation in the primary prophylaxis of variceal hemorrhage: a multicentre randomized controlled trial. J Hepatol 2014; 60:757.

3. Tripathi D, Handley K, Holden L, et al. Clinical Trial: A Multicentre Randomised Controlled Trial of Carvedilol Versus Variceal Band Ligation in Primary Prevention of Variceal Bleeding in Liver Cirrhosis (CALIBRE Trial). Aliment Pharmacol Ther 2025; 61:1740.

pressure induced injury/ulcer

Q: As per the National Pressure Injury Advisory Panel (NPIAP) system, which term is preferred for pressure-induced skin and soft tissue injuries? - select one

A) "pressure injury" 

B) "pressure ulcer" 

Answer: A

This question aims to help students understand the importance of nomenclature in medical science.

Pressure-induced skin and soft tissue injuries are common in hospitals and have been considered a marker of poor patient safety and healthcare quality in any given institution. 

The NPIAP system prefers the term "pressure injury" instead of "pressure ulcer" because lesser degrees of skin damage due to pressure may not be associated with skin ulceration, which is considered stage 1. Additionally, deep tissue pressure injury can occur without overlying skin ulceration.

#dermatology

#healthcare-quality

#patient-safety

Reference:

National Pressure Injury Advisory Panel. NPIAP Pressure Injury Stages. Available at: https://npiap.com/ (Accessed on August 29, 2025).

DVT and PE

Q: Which of the following in Pulmonary Embolism (PE) with coexisting Deep vein thrombosis (DVT) is an indicator of increased risk for death? - select one

A) Hypernatremia

B) Hyponatremia 

Answer: B

PE patients without DVT usually do better than patients with coexisting DVT. There are a few clinical and laboratory signs that predict high mortality in patients with PE and a coexisting DVT, either in the upper or lower extremities. These include:

• Hyponatremia
• Indicators of kidney dysfunction 
• Serum lactate (>2 mmol/L)
• Leucocytosis (>12.6 x 109/L) 
• Charlson comorbidity index ≥1
• Residual pulmonary vascular obstruction 
• Age ≥65 years 
• Tachycardia

#hematology

#pulmonary

#electrolytes

References:

1. Scherz N, Labarère J, Méan M, et al. Prognostic importance of hyponatremia in patients with acute pulmonary embolism. Am J Respir Crit Care Med 2010; 182:1178.

2. Jiménez D, Aujesky D, Díaz G, et al. Prognostic significance of deep vein thrombosis in patients presenting with acute symptomatic pulmonary embolism. Am J Respir Crit Care Med 2010; 181:983.

3. Venetz C, Labarère J, Jiménez D, Aujesky D. White blood cell count and mortality in patients with acute pulmonary embolism. Am J Hematol 2013; 88:677.

4. Jaureguízar A, Jiménez D, Bikdeli B, et al. Heart Rate and Mortality in Patients With Acute Symptomatic Pulmonary Embolism. Chest 2022; 161:524.

5. Murgier M, Bertoletti L, Darmon M, et al. Frequency and prognostic impact of acute kidney injury in patients with acute pulmonary embolism. Data from the RIETE registry. Int J Cardiol 2019; 291:121.

Lab abnormalities in Adrenal Crisis

Question: Name seven laboratory abnormalities expected in Adrenal Crisis.

Answer:

• Anemia
• Lymphocytosis
• Eosinophilia
• Hyponatremia
• Hyperkalemia
• Metabolic acidosis
• Hypoglycemia

#endocrinology

#laboratory-medicine

Further readings:

1. Vaidya A, Findling J, Bancos I. Adrenal Insufficiency in Adults: A Review. JAMA. 2025 Aug 26;334(8):714-725. doi: 10.1001/jama.2025.5485. PMID: 40522647.

2. Puar TH, Stikkelbroeck NM, Smans LC, Zelissen PM, Hermus AR. Adrenal Crisis: Still a Deadly Event in the 21st Century. Am J Med. 2016 Mar;129(3):339.e1-9. doi: 10.1016/j.amjmed.2015.08.021. Epub 2015 Sep 9. PMID: 26363354.

3. Lewis A, Thant AA, Aslam A, Aung PPM, Azmi S. Diagnosis and management of adrenal insufficiency. Clin Med (Lond). 2023 Mar;23(2):115-118. doi: 10.7861/clinmed.2023-0067. PMID: 36958832; PMCID: PMC11046533.

4. Dineen R, Thompson CJ, Sherlock M. Adrenal crisis: prevention and management in adult patients. Ther Adv Endocrinol Metab. 2019 Jun 13;10:2042018819848218. doi: 10.1177/2042018819848218. PMID: 31223468; PMCID: PMC6566489.

Triad of Löfgren's syndrome.

Q: In female patients who get diagnosed with Löfgren syndrome, which is more common? - select one

A) Eerythema nodosum 

B) Ankle arthropathy

Answer: A

Löfgren syndrome is a triad of sarcoidosis with

• acute-onset fever
• hilar adenopathy, 
• erythema nodosum or bilateral ankle inflammation

Interestingly, erythema nodosum or bilateral ankle inflammation strikes differently in males and females. Löfgren syndrome is more common in females with variable proportions of erythema nodosum. Males are more prone to ankle arthropathy. It may also affect knees, wrists, or elbow joints. 

The presence of Löfgren syndrome has a high diagnostic specificity for sarcoidosis. As they can also be present in acute tuberculosis and acute presentations of endemic fungal infections, including histoplasmosis, blastomycosis, and coccidioidosis, they should be ruled out.

#rheumatology

References:

1. Judson MA. The Clinical Features of Sarcoidosis: A Comprehensive Review. Clin Rev Allergy Immunol 2015; 49:63.

2. Grunewald J, Eklund A. Sex-specific manifestations of Löfgren's syndrome. Am J Respir Crit Care Med 2007; 175:40.

3. Statement on sarcoidosis. Joint Statement of the American Thoracic Society (ATS), the European Respiratory Society (ERS) and the World Association of Sarcoidosis and Other Granulomatous Disorders (WASOG) adopted by the ATS Board of Directors and by the ERS Executive Committee, February 1999. Am J Respir Crit Care Med 1999; 160:736.

4. Saha BK, Chong W, Bonnier A, Wallace S. Löfgren Syndrome in Histoplasma Endemic Rural America. Am J Med Sci 2020; 360:419.

elevation of serum alkaline phosphatase in acute cholecystitis

Q: Elevation of alkaline phosphatase in acute cholecystitis raises the possibility of? - Select one

A) cystic duct obstruction

B) biliary duct obstruction 

Answer: B

In uncomplicated acute cholecystitis, elevation of serum total bilirubin and alkaline phosphatase concentrations is uncommon because the obstruction is typically limited to the cystic duct. If clinical signs are present with elevated serum total bilirubin and alkaline phosphatase concentrations, concern should be raised for possible biliary obstruction and/or more complicated situations, such as cholangitis, choledocholithiasis, or Mirizzi syndrome, where a gallstone is impacted in the distal cystic duct, causing extrinsic compression of the common bile duct.

#hepatology

References:

1. Siddique A, Kowdley KV. Approach to a patient with elevated serum alkaline phosphatase. Clin Liver Dis. 2012 May;16(2):199-229. doi: 10.1016/j.cld.2012.03.012. Epub 2012 Apr 6. PMID: 22541695; PMCID: PMC3341633.

2. Pellegrini CA, Thomas MJ, Way LW. Bilirubin and alkaline phosphatase values before and after surgery for biliary obstruction. Am J Surg. 1982 Jan;143(1):67-73. doi: 10.1016/0002-9610(82)90131-3. PMID: 7053658.

3. Toda G, Ikeda Y, Kako M, Oka H, Oda T. Mechanism of elevation of serum alkaline phosphatase activity in biliary obstruction: an experimental study. Clin Chim Acta. 1980 Oct 23;107(1-2):85-96. doi: 10.1016/0009-8981(80)90417-9. PMID: 7428180.

DTIs and DOACs

Q: All of the following are orally active direct factor Xa inhibitors except

A) rivaroxaban (Xarelto)

B) apixaban (Eliquis)

C) edoxaban (Lixiana, Savaysa)

D) betrixaban (Bevyxxa)

E) dabigatran (Pradaxa)

Answer: E

Dabigatran (Pradaxa) is the orally active Direct Thrombin Inhibitor (DTI); all others are orally active direct factor Xa inhibitors.

Reversal for Dabigatran is available. Also, it is dialysable. Dabigatran does not require frequent blood tests for INR monitoring. The half-life of Dabigatran is 12-17 hours. 

#pharmacology

#hematology

References:

1. Barnes GD, Ageno W, Ansell J, et al. Recommendation on the nomenclature for oral anticoagulants: communication from the SSC of the ISTH. J Thromb Haemost 2015; 13:1154.

2. Ganetsky M, Babu KM, Salhanick SD, Brown RS, Boyer EW. Dabigatran: review of pharmacology and management of bleeding complications of this novel oral anticoagulant. J Med Toxicol. 2011 Dec;7(4):281-7. doi: 10.1007/s13181-011-0178-y. PMID: 21887485; PMCID: PMC3550194.

3. Comin J, Kallmes DF. Dabigatran (Pradaxa). AJNR Am J Neuroradiol. 2012 Mar;33(3):426-8. doi: 10.3174/ajnr.A3000. Epub 2012 Feb 16. PMID: 22345499; PMCID: PMC7966436.