Octreotide and chylothorax

Q: How does octreotide help in the management of chylothorax?

Answer: By decreasing intestinal fat absorption

Chylothorax continues to remain a challenging situation for both traumatic, including post-surgical, as well as non-traumatic etiologies. Various dietary, surgical, and pharmacological interventions have been tried with varying degrees of success.

Somatostatin analogs such as octreotide and lanreotide are known to decrease intestinal fat absorption. A short course of subcutaneous (SQ) octreotide, 50 to 200 micrograms every 8 hours for 1 to 2 weeks, has been proposed by experts, with caution to discontinue after 2 weeks regardless of the response. 

Caution should be exercised to monitor for cutaneous flushing, nausea, diarrhea, sinus bradycardia, injection-site pain, and elevated liver function tests.

#Pulmonary

References:

1. Mincher L, Evans J, Jenner MW, Varney VA. The successful treatment of chylous effusions in malignant disease with octreotide. Clin Oncol (R Coll Radiol) 2005; 17:118.

2. Evans J, Clark MF, Mincher L, Varney VA. Chylous effusions complicating lymphoma: a serious event with octreotide as a treatment option. Hematol Oncol 2003; 21:77.

3. Kalomenidis I. Octreotide and chylothorax. Curr Opin Pulm Med. 2006 Jul;12(4):264-7. doi: 10.1097/01.mcp.0000230629.73139.26. PMID: 16825878.

ACE-I with diuretics in AA patients

Q: African American (AA) patients, with the addition of a low dose of a thiazide diuretic to an ACE inhibitor, get a similar response to a fall in blood pressure (BP) as comparable to White patients.

A) True

B) False

Answer: A

It is conventionally and, to some extent, rightly believed that AA patients don't respond to ACE (angiotensin-converting enzyme) inhibitors as well as white patients. This notion has led to improper management of hypertension in AA patients many times. Evidence shows that the addition of just a low dose of a thiazide diuretic to an ACE inhibitor can give a comparable fall in BP as in White patients. 

Mechanism of action: ACE inhibitors and diuretics have a synergistic effect: diuretic-induced hypovolemia increases renin release and subsequent angiotensin II production. This effect is prevented by converting enzyme inhibition, resulting in a marked reduction in BP. A similar mechanism applies to the synergistic enhancement observed with dietary sodium restriction and an ACE inhibitor.

Other effects of adding ACE inhibitors to diuretics are:

• prevention of hypokalemia, as reduced angiotensin II formation induced by the ACE inhibitor decreases aldosterone secretion. 
• prevention of  glucose intolerance, hyperlipidemia, and hyperuricemia (some of the diuretic-induced effects)

#hemodynamics

References:

1. Townsend RR, Holland OB. Combination of converting enzyme inhibitor with diuretic for the treatment of hypertension. Arch Intern Med 1990; 150:1175.

2. Pollare T, Lithell H, Berne C. A comparison of the effects of hydrochlorothiazide and captopril on glucose and lipid metabolism in patients with hypertension. N Engl J Med 1989; 321:868.

3. Borghi C, Soldati M, Bragagni A, Cicero AFG. Safety implications of combining ACE inhibitors with thiazides for the treatment of hypertensive patients. Expert Opin Drug Saf. 2020 Dec;19(12):1577-1583. doi: 10.1080/14740338.2020.1836151. PMID: 33047990.

SAAG in CHF

Q: One of the advantages of the serum-to-ascites albumin gradient (SAAG) in congestive heart failure (CHF) is that it can predict treatment efficacy.

A) True

B) False

Answer: A

SAAG can predict portal hypertension with 97 percent accuracy. It is easy to calculate by subtracting the ascitic fluid albumin value from the serum albumin value, which should be obtained the same day. 

• gradient ≥1.1 g/dL (≥11 g/L) predicts portal hypertension with 97 percent accuracy
• gradient <1.1 g/dL (<11 g/L) negates portal hypertension

Patients with CHF can narrow their gradient during diuresis, but patients with cirrhosis rarely do unless blood pressure or portal pressure decreases significantly. This is an added advantage of SAAG in establishing a differential diagnosis.

#hepatology

#GI

#cardiology

References:

1. Runyon BA, Montano AA, Akriviadis EA, et al. The serum-ascites albumin gradient is superior to the exudate-transudate concept in the differential diagnosis of ascites. Ann Intern Med 1992; 117:215.

2. Hoefs JC. Serum protein concentration and portal pressure determine the ascitic fluid protein concentration in patients with chronic liver disease. J Lab Clin Med 1983; 102:260.

3. Goh ZNL, Teo RYL, Chung BK, Wong AC, Seak CJ. At the heart of the problem: congestive cardiac failure as a cause of ascites: A narrative review. Medicine (Baltimore). 2022 Aug 5;101(31):e29951. doi: 10.1097/MD.0000000000029951. PMID: 35945724; PMCID: PMC9351856.

DPP-4 with metformin

Q: Dipeptidyl peptidase 4 (DPP-4) inhibitors should not be combined with metformin to avoid the risk of severe hypoglycemia.

A) True

B) False

Answer: B

DPP-4 inhibitors, the most popular one in the USA is sitagliptin (trade name Januvia), have a low risk of hypoglycemia even when used as an add-on therapy with metformin. The risk of hypoglycemia is higher when combined with insulin or sulfonylureas, which are well-known to cause hypoglycemia by themselves. 

This characteristic of a lower rate of hypoglycemia is particularly useful in patients with chronic renal disease, including patients who require dialysis.

Similarly, good or bad, they have minimal effect on body weight.

#endocrinology

References:

1.  Nauck MA, Meininger G, Sheng D, et al. Efficacy and safety of the dipeptidyl peptidase-4 inhibitor, sitagliptin, compared with the sulfonylurea, glipizide, in patients with type 2 diabetes inadequately controlled on metformin alone: a randomized, double-blind, non-inferiority trial. Diabetes Obes Metab 2007; 9:194.

2. Gallwitz B, Rosenstock J, Rauch T, et al. 2-year efficacy and safety of linagliptin compared with glimepiride in patients with type 2 diabetes inadequately controlled on metformin: a randomised, double-blind, non-inferiority trial. Lancet 2012; 380:475.

3. Arjona Ferreira JC, Corry D, Mogensen CE, et al. Efficacy and safety of sitagliptin in patients with type 2 diabetes and ESRD receiving dialysis: a 54-week randomized trial. Am J Kidney Dis 2013; 61:579.

COVID-19, permissive hypercapnia,and permissive hypoxemia

Q: 72 years old male is admitted to the ICU with pneumonia and requires 12 L/min of oxygen flow. Respiratory culture from admission shows COVID-19. Targeting PaO2 ≥60 mmHg rather than ≥90 mmHg may result in more days alive without ventilatory support.

A) True

B) False

Answer: A

Permissive hypoxemia appears to have benefit in patients with COVID-19 who require mechanical ventilation. The HOT-COVID Randomized Clinical Trial, published in JAMA in 2024 at the tail end of the COVID-19 pandemic, went relatively unnoticed. It was a very strong trial with an average of 350 patients in each arm, showing that though there may not be a mortality benefit, patients receiving at least 10 L/minute of oxygen or mechanical ventilation, targeting PaO2 ≥60 mmHg, were associated with more days alive without ventilatory support compared with a target ≥90 mmHg.

The underlying mechanism of action may be due to the Bohr Effect, in which permissive hypercapnia, and thus concomitant permissive hypoxemia, may cause more O₂ to be released in metabolically active tissues.

#pulmonary

#ventilation

#ID

Reference:

1. Nielsen FM, Klitgaard TL, Siegemund M, et al. Lower vs Higher Oxygenation Target and Days Alive Without Life Support in COVID-19: The HOT-COVID Randomized Clinical Trial. JAMA 2024; 331:1185.

Social factors in suicide

Q: Immigrants are at higher risk for suicide than the citizens of the host country.

A) True

B) False

Answer: B

Contrary to popular belief, immigrants are at less risk for suicide than the citizens of the native country. Though no single theory can explain this, the postulation is that immigrants in a new country still have hope of doing better after leaving the hopelessness of their home country behind. On the other hand, natives may feel more hopeless with the given system. 

Although the data came from a European country (reference #1), it appears applicable to other contexts. Other social protective factors against suicide are:

• Being married
• Pregnant 
• A parent
• Socially connected
• Financially independent
• Religious 

#psychiatry

References:

1. Brennecke G, Stoeber FS, Kettner M, et al. Suicide among immigrants in Germany. J Affect Disord 2020; 274:435.

2. Hung GC, Cheng CT, Jhong JR, et al. Risk and protective factors for suicide mortality among patients with alcohol dependence. J Clin Psychiatry 2015; 76:1687.

3. Miola A, Tondo L, Pinna M, et al. Suicidal risk and protective factors in major affective disorders: A prospective cohort study of 4307 participants. J Affect Disord 2023; 338:189.

4. Qin P, Mortensen PB. The impact of parental status on the risk of completed suicide. Arch Gen Psychiatry 2003; 60:797.

RDW, RDW-SD and RDW-CV

Q: What's the difference between RDW, RDW-SD and RDW-SC?

Answer: 

Red cell distribution width (RDW) signifies either microcytosis (low RDW) or macrocytosis (high RDW). The two major causes of microcytosis, probably accompanied by hypochromia, are thalassemia and iron deficiency.

RDW- Standard Deviation (RDW-SD) measures the actual variation in size of red blood cells. A high RDW-SD means cells vary significantly in size. RDW-SD is an actual, physical measurement of the cell volume distribution curve at a level 20% above the baseline of the histogram.

RDW — Coefficient of Variation (RDW-CV) is a calculation influenced by average red blood cell size. It is usually considered less precise than RDW-SD because it measures the histogram at the midpoint.

RDW-SD, RDW-CV, and Mean Corpuscular Volume (MCV) should be read together for better understanding. 

#hematology

#laboratory science

References:

1. Sarma PR. Red Cell Indices. In: Walker HK, Hall WD, Hurst JW, editors. Clinical Methods: The History, Physical, and Laboratory Examinations. 3rd edition. Boston: Butterworths; 1990. Chapter 152. Available from: https://www.ncbi.nlm.nih.gov/books/NBK260/

2. Salvagno GL, Sanchis-Gomar F, Picanza A, Lippi G. Red blood cell distribution width: A simple parameter with multiple clinical applications. Crit Rev Clin Lab Sci. 2015;52(2):86-105. doi: 10.3109/10408363.2014.992064. Epub 2014 Dec 23. PMID: 25535770.

3. Yang K, Sun B, Zhang S, Pan Y, Fang J. RDW-SD is Superior to RDW-CV in Reflecting Liver Fibrosis Stage in Patients with Chronic Hepatitis B. Infect Drug Resist. 2023 Oct 27;16:6881-6891. doi: 10.2147/IDR.S427047. PMID: 37920477; PMCID: PMC10619233.

Plasmapheresis during pregnancy

Q: A 32-year-old female, first-time, 26 weeks pregnant, with a known history of Myasthenia Gravis (MG), presented with severe myasthenia crisis requiring intubation. Plasmapheresis should not be performed during pregnancy.

 

A) True

B) False

Answer: B

Two major rescue therapies for myasthenic crisis are:

• Plasmapheresis 
• High-dose intravenous immune globulin

They are both safe in pregnancy.

#Ob-gyn

#neurology

References:

1. Varner M. Myasthenia gravis and pregnancy. Clin Obstet Gynecol 2013; 56:372.

2. Sanders DB, Wolfe GI, Benatar M, et al. International consensus guidance for management of myasthenia gravis: Executive summary. Neurology 2016; 87:419.

3. Watson WJ, Katz VL, Bowes WA Jr. Plasmapheresis during pregnancy. Obstet Gynecol 1990; 76:451.

SPS in hyperkalemia

Q: Sodium polystyrene sulfonate (SPS) or other cation-exchange resins should be utilized only in? - select one

A) acute hyperkalemia 

B) chronic hyperkalemia 

Answer: A

Sodium polystyrene sulfonate (SPS) or other cation-exchange resins are usually administered in combination with sorbitol to treat hyperkalemia. 

They were immensely popular in ICUs for the control of hyperkalemia, but evidence shows that they carry more harm than benefit, particularly causing potentially fatal intestinal necrosis and fluid overload as they exchange K for Na. 

Interestingly, some experts claim that the most effect comes from the laxative effect of added sorbitol. That's why SPS or other resins should be used only for short-term use and only in a semi-hyperkalemic emergency.

#electrolytes

References:

1. Hagan AE, Farrington CA, Wall GC, Belz MM. Sodium polystyrene sulfonate for the treatment of acute hyperkalemia: a retrospective study. Clin Nephrol. 2016 Jan;85(1):38-43. doi: 10.5414/CN108628. PMID: 26587776.

2. Rossignol P, Pitt B. Sodium polystyrene is unsafe and should not be prescribed for the treatment of hyperkalaemia: primum non nocere! Clin Kidney J. 2023 Apr 21;16(8):1221-1225. doi: 10.1093/ckj/sfad090. PMID: 37529653; PMCID: PMC10387396.

capsid inhibitor for HIV-1 treatment and prevention

Q: How do capsid inhibitors work in HIV?

Answer: They disrupt HIV capsid protein functions

Lenacapavir is the capsid inhibitor approved by the FDA in 2022. It has a unique mechanism of action that disrupts HIV capsid protein functions and impacts key protein-protein interactions necessary for viral entry and virion assembly.

It is very effective in patients with multidrug-resistant HIV, as well as in preventing HIV infection. It is administered in combination with an optimized background ART regimen. 

The beauty of this drug is that, after an initial induction regimen that includes an oral lenacapavir component, it is administered only every 6 months as a subcutaneous injection, thereby improving adherence, particularly in resource-limited countries.

#ID

#pharmacology

References:

1. Prather C, Lee A, Yen C. Lenacapavir: A first-in-class capsid inhibitor for the treatment of highly treatment-resistant HIV. Am J Health Syst Pharm. 2023 Dec 5;80(24):1774-1780. doi: 10.1093/ajhp/zxad223. PMID: 37767713.

2. Segal-Maurer S, DeJesus E, Stellbrink HJ, et al. Capsid Inhibition with Lenacapavir in Multidrug-Resistant HIV-1 Infection. N Engl J Med 2022; 386:1793.

3. De Clercq E, Zhang Y, Li G, Deng Y, Khouri R, Růžek D, Król E, Tan L. Lenacapavir: A capsid inhibitor for HIV-1 treatment and prevention. Biochem Pharmacol. 2025 Oct;240:117125. doi: 10.1016/j.bcp.2025.117125. Epub 2025 Jul 5. PMID: 40623458.

Brugada Syndrome in psychiatric disorder

Q: Which psychological condition is found to be associated with Brugada pattern ECGs? - Select one

A) Autism Spectrum Disorder  

B) Bipolar Disorder

C) Obsessive-Compulsive Disorders

D) Schizophrenia 

E) Social Anxiety

Answer: D

Brugada pattern ECGs are more significantly common in schizophrenia, and this association is without any significant impact of antipsychotic medications with sodium channel blocking activity.

Although the cause is not known, the same electrolyte channel dysfunction is suspected. It keeps the risk of sudden death in these patients high, an important element in the care of these patients, particularly when they are in hospitals and subject to various medications.

#psychiatry

#cardiology

References:

1. Blom MT, Cohen D, Seldenrijk A, et al. Brugada syndrome ECG is highly prevalent in schizophrenia. Circ Arrhythm Electrophysiol 2014; 7:384.

2. Rastogi A, Viani-Walsh D, Akbari S, Gall N, Gaughran F, Lally J. Pathogenesis and management of Brugada syndrome in schizophrenia: A scoping review. Gen Hosp Psychiatry. 2020 Nov-Dec;67:83-91. doi: 10.1016/j.genhosppsych.2020.09.003. Epub 2020 Oct 6. PMID: 33065406; PMCID: PMC7537626.

3. Treur JL, Thijssen AB, Smit DJA, Tadros R, Veeneman RR, Denys D, Vermeulen JM, Barc J, Bergstedt J, Pasman JA, Bezzina CR, Verweij KJH. Associations of schizophrenia with arrhythmic disorders and electrocardiogram traits: genetic exploration of population samples. Br J Psychiatry. 2025 Mar;226(3):153-161. doi: 10.1192/bjp.2024.165. Epub 2024 Nov 8. PMID: 39512114; PMCID: PMC7616879.

4. Sutterland AL, Blom MT, Ladee K, Lubbers JJM, Cohen D, de Haan L, Tan HL. Increased prevalence of ECG suspicious for Brugada Syndrome in recent onset schizophrenia spectrum disorders. Schizophr Res. 2019 Aug;210:59-65. doi: 10.1016/j.schres.2019.06.013. Epub 2019 Jun 24. PMID: 31248748.