Small bowel vs colon as source of diarrhea

Q: All of the following are sources of diarrhea from the colon except? (select one)

A) Vibrio cholerae

B) Shigella

C) Clostridioides difficile

D) Yersinia

E) Enteroinvasive E. coli

Answer: A

The objective of this question is to highlight the importance of proper history during clinical exams. Subsequently, it may guide towards the appropriate diagnosis. The probable bugs in diarrhea are usually either in the small bowel or colon, which may have different characteristics of diarrhea. Diarrhea of small bowel origin is usually large volume, watery, and results in cramps, gas, and bloating. Fever is unlikely. In contrast, diarrhea from colon is small volume and associated with painful bowel movements. Fever and blood/mucoid in stool are common. Inflammatory cells are seen on stool microscopy, which is unlikely in small bowel diarrhea.

Salmonella, Escherichia coli, Clostridium perfringens, Staphylococcus aureus, Bacillus cereus, and Vibrio cholerae usually originate in the small bowel.

Shigella, Clostridioides difficile, Yersinia, and Enteroinvasive E. coli are mostly found in the colon.

#GI

#ID

References: 

1. Lam C, Chaddock G, Marciani Laurea L, Costigan C, Cox E, Hoad C, Pritchard S, Gowland P, Spiller R. Distinct Abnormalities of Small Bowel and Regional Colonic Volumes in Subtypes of Irritable Bowel Syndrome Revealed by MRI. Am J Gastroenterol. 2017 Feb;112(2):346-355. doi: 10.1038/ajg.2016.538. Epub 2016 Dec 13. PMID: 27958282; PMCID: PMC5318666.

2. Sweetser S. Evaluating the patient with diarrhea: a case-based approach. Mayo Clin Proc. 2012;87(6):596-602. doi:10.1016/j.mayocp.2012.02.015

3. Murray JA, Rubio-Tapia A. Diarrhoea due to small bowel diseases. Best Pract Res Clin Gastroenterol. 2012;26(5):581-600. doi:10.1016/j.bpg.2012.11.013

Provocative angiography

Q: What is provocative Angiography?

Answer: Provocative angiography is rarely applied in lower gastrointestinal bleed (GIB), in case the site of bleeding cannot be identified by other conventional methods. 

Provocative challenge is given with vasodilators, anticoagulants, and/or thrombolytics. The commonly used agents are urokinase, heparin, nicardipine in 3 cases, alprostadil, and isosorbide.       

Although seem paradoxical but can be an effective way of identifying the area of bleed where there is a high risk of mortality.

#procedures

Reference:

Kariya S, Nakatani M, Ono Y, Maruyama T, Ueno Y, Yoshida A, Komemushi A, Tanigawa N. Provocative angiography for lower gastrointestinal bleeding. Jpn J Radiol. 2020 Mar;38(3):248-255. doi: 10.1007/s11604-019-00909-0. Epub 2019 Dec 13. PMID: 31834578.

Linezolid induced LA

Q; Lactic acidosis from Linezolid usually clears quickly once the drug is stopped.

A) True

B) False

Answer: B

Lactic acidosis from linezolid can be fatal. It usually occurs in patients on long-term infusion but may occur in ICU within a week of administration. The mechanism of action is secondary to mitochondrial toxicity. 

It may take up to 14 days for lactate levels to normalize.

#acid-base

#pharmacology

References:

1. Santini A, Ronchi D, Garbellini M, et al. Linezolid-induced lactic acidosis: the thin line between bacterial and mitochondrial ribosomes. Expert Opin Drug Saf 2017; 16:833. 

2. Wiener M, Guo Y, Patel G, Fries BC. Lactic acidosis after treatment with linezolid. Infection 2007; 35:278. 

3. Apodaca AA, Rakita RM. Linezolid-induced lactic acidosis. N Engl J Med 2003; 348:86.

Median time intervals of different anaphylaxes

Q: What is the median time interval between onset of symptoms and respiratory or cardiac arrest in iatrogenic anaphylaxis? (select one)

A) 5 minutes 

B) 15 minutes 

C) 30 minutes 

Answer: A

Although every human is different, at least one study found the ballpark figure of different median time interval between onset of symptoms and respiratory or cardiac arrest:

• iatrogenic anaphylaxis - 5 minutes
• stinging insect venom-induced anaphylaxis - 15 minutes
• food-induced anaphylaxis - 30 minutes

This is a good reminder for clinicians who encounter in-patient anaphylaxes.

#allergy

Reference:

Pumphrey RS. Lessons for management of anaphylaxis from a study of fatal reactions. Clin Exp Allergy 2000; 30:1144.

Platypnea-orthodeoxia syndrome

Q: What is platypnea-orthodeoxia syndrome?

Answer: Platypnea-orthodeoxia syndrome is characterized by both dyspnea (platypnea) and desaturation (orthodeoxia) in upright position but improve in supine position. It is usually due to high right atrial pressure causing right-to-left shunting. Some of the major reasons are patent foramen ovale (PFO), pericardial effusion, constrictive pericarditis, emphysema, amiodarone pulmonary toxicity, pneumonectomy, and cirrhosis.

#pulmonary

#cardiology

References:

1. Cheng TO. Platypnea-orthodeoxia syndrome: etiology, differential diagnosis, and management. Catheter Cardiovasc Interv 1999; 47:64.

2. Rodrigues P, Palma P, Sousa-Pereira L. Platypnea-orthodeoxia syndrome in review: defining a new disease? Cardiology. 2012;123(1):15-23. doi: 10.1159/000339872. Epub 2012 Aug 31. PMID: 22948714.

Timing of Type B AD

Q: Hyperacute phase of acute type B aortic dissection is? (select one)

A) <12 hours

B) <24 hours

Answer: B

 

Conventionally Type B aortic dissection is classified as acute (less than 14 days) or chronic (more than14 days). Recently, the Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) has updated the reporting standards for type B aortic dissections from the onset of symptoms:

• Hyperacute: <24 hours
• Acute: 1 to 14 days
• Subacute: 15 to 90 days
• Chronic: >90 days

#vascular

#cardio-thoracic

Reference:

Lombardi JV, Hughes GC, Appoo JJ, et al. Society for Vascular Surgery (SVS) and Society of Thoracic Surgeons (STS) reporting standards for type B aortic dissections. J Vasc Surg 2020; 71:723.

Leriche syndrome

Q: What is Leriche syndrome?

Answer: Leriche syndrome is described seven decades ago as a part of bedside clinical exam of peripheral arterial disease (PAD). It is the triad of 

• claudication
• absent or diminished femoral pulses
• erectile dysfunction

Despite the availability of angiograms and other radiological modalities, bedside exams continue to be the first line of diagnostic evaluation in PAD.

#vascular

#surgical-critical-care

References:

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

2. Frederick M, Newman J, Kohlwes J. Leriche syndrome. J Gen Intern Med 2010; 25:1102.

TTBI

Q: The incidence/risk of transfusion-transmitted bacterial infection (TTBI) is higher than the transfusion-transmitted viral infection (TTVI)?

A) True

B) False

Answer: A

It is a less known fact that TTBI can occur not only through the donor blood but can also occur through the donor skin phlebotomist's skin, or during preparation and packaging of the product. In case TTBI occurs, four bacterias should be highly considered:

• Yersinia enterocolitica 
• Pseudomonas fluorescens 
• Enterobacter 
• Serratia

These bacteria are capable of multiplying in cold.

#transfusion

#ID

References:

1. Vasconcelos E, Seghatchian J. Bacterial contamination in blood components and preventative strategies: an overview. Transfus Apher Sci 2004; 31:155. 

2. Jacobs MR, Palavecino E, Yomtovian R. Don't bug me: the problem of bacterial contamination of blood components--challenges and solutions. Transfusion 2001; 41:1331. 

3. Sugai Y, Sugai K, Fuse A. Current status of bacterial contamination of autologous blood for transfusion. Transfus Apher Sci 2001; 24:255. 

4. Casewell MW, Slater NG, Cooper JE. Operating theatre water-baths as a cause of pseudomonas septicaemia. J Hosp Infect 1981; 2:237. 

5. Wagner SJ. Transfusion-transmitted bacterial infection: risks, sources and interventions. Vox Sang 2004; 86:157. 

Spasticity and Rigidity

Q: What is the difference between spasticity and rigidity?

  

Answer: Simple clinical exam at the bedside provides various clues to the underlying pathology. During neuro exam, it may be of importance to differentiate between spasticity and rigidity.

Spasticity is also known as "clasp-knife phenomenon". Here a limb moves freely for a little while, then there is a "catch" requiring a force to move the limb, followed by a sudden release, and limb move freely again. 

Rigidity requires increased resistance throughout the movement and get accentuated by distracting the patient. There are two kinds of rigidity. When resistance is uniform throughout the movement, is called Lead-pipe rigidity. In contrast, resistance which has rhythmic interruption is called Cogwheel rigidity.

It would be of interest to know the difference between these two phenomena is intriguing academicians for the last six decades (see reference # 2).

#neurology

#clinical-exam

References:

1. Fearon C, Doherty L, Lynch T. How Do I Examine Rigidity and Spasticity?. Mov Disord Clin Pract. 2015;2(2):204. Published 2015 Mar 28. doi:10.1002/mdc3.12147

2. HERMAN R. The physiologic basis of tone, spasticity and rigidity. Arch Phys Med Rehabil. 1962 Mar;43:108-14. PMID: 13906696.

Myxedema

Q: Edema in myxedema is usually? (select one)

A) pitting 

B) non-pitting 

Answer: B

The objective of this question is to underline the importance of bedside clinical exam. The two hallmarks clinical signs of myxedema  are

• mental status change, and
• hypothermia (may mask signs of infection)

Other common signs are hypotension, low respiratory and heart rate, hyponatremia, hypoglycemia, puffiness of the hands and face, a thickened nose, swollen lips, and an enlarged tongue. The nonpitting edema is due to deposits of albumin and mucin in the skin and other tissues, known as myxedema.

#endocrine

References:

1. Ono Y, Ono S, Yasunaga H, et al. Clinical characteristics and outcomes of myxedema coma: Analysis of a national inpatient database in Japan. J Epidemiol 2017; 27:117. 

2. Wiersinga WM. Myxedema and Coma (Severe Hypothyroidism) [Updated 2018 Apr 25]. In: Feingold KR, Anawalt B, Boyce A, et al., editors. Endotext [Internet]. South Dartmouth (MA): MDText.com, Inc.; 2000-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK279007/

PPH - predictor

Q: Which of the following is a good predictor of postpartum hemorrhage (PPH)? (select one)

A) low fibrinogen 

B) hypotension

C) tachycardia

D) low hematocrit 

Answer: A

Low blood pressure and tachycardia usually do not manifest in pregnant patients till late and are a poor indicator of ongoing PPH (choice B and C). On the same token, in severe acute hemorrhage, it takes time before hematocrit shows a drop in the laboratory (choice D).

A fibrinogen level below 200 mg/dL is a reliable predictor of severe PPH, where massive blood transfusion or surgical/procedural intervention is required (choice A).

#ob-gyn

#surgical-critical-care

Reference:

1. Bell SF, Collis RE, Bailey C, et al. The incidence, aetiology, and coagulation management of massive postpartum haemorrhage: a two-year national prospective cohort study. Int J Obstet Anesth 2021; 47:102983.

2. Bonnar J. Massive obstetric haemorrhage. Baillieres Best Pract Res Clin Obstet Gynaecol 2000; 14:1.

bag-mask ventilation in an edentulous patient

Q: Describe few tricks to have proper mask seal in edentulous patients during bag-mask ventilation?

Answer: Edentulous patients offer a challenge to have proper mask seal during bag-mask ventilation. Few tricks which may help:

1. Reinsert the false teeth.

2. Expand cheeks with 4 x 4 gauze.

3. Lower lip placement of mask : The caudad end of the face mask is positioned between the lower lip and the alveolar ridge.

4. Perform two-handed thenar eminence method: The index fingers lift the soft tissue of the cheeks against the rim of the facemask, while the remaining three fingers pull the jaw upward.

#procedures

References: 

1. Conlon NP, Sullivan RP, Herbison PG, et al. The effect of leaving dentures in place on bag-mask ventilation at induction of general anesthesia. Anesth Analg 2007; 105:370. 

2. Racine SX, Solis A, Hamou NA, et al. Face mask ventilation in edentulous patients: a comparison of mandibular groove and lower lip placement. Anesthesiology 2010; 112:1190. 

3. Jain D, Sahni N, Goel N, et al. The C-E versus modified V-E hand positions for holding a face mask when ventilating an edentulous patient: A randomised crossover trial. Eur J Anaesthesiol 2021; 38:1194.

Coffee Bean sign

Q: What is "Bent Inner Tube" sign?

Answer: pathognomonic sign of sigmoid volvulus  

Sigmoid volvulus may presents as a U-shaped, distended sigmoid colon, which may appear as an ahaustral collection of gas extending from the pelvis to the right upper quadrant up to the diaphragm. This is highly suggestive but not a confirmatory sign. CT scan should be performed. This can also be present in other causes of distal colonic obstruction, colonic pseudo-obstruction, and toxic megacolon. It is also referred to as coffee bean, kidney bean or omega sign.

Image used from Wikimedia Commons, the free media repository.

#surgical-critical-care

#ID

Reference:

Stavride E, Plakias C. Coffee bean sign: Its meaning and importance. Clin Case Rep. 2020 Jun 26;8(10):2086-2087. doi: 10.1002/ccr3.3064. PMID: 33088563; PMCID: PMC7562879.

MESA score

Q: MESA risk score for cardiovascular disease includes? (select one)

A) Ethnic background

B) Estrogen use

Answer: A

The Multi-Ethnic Study of Atherosclerosis (MESA) is a validated risk score published in 2015. This calculator looks for African American, Chinese American, Hispanic, and Non-Hispanic white backgrounds. MESA also allows an option to incorporate coronary artery calcium (CAC) score.

Calculator can be found at 

https://www.mesa-nhlbi.org/MESACHDRisk/MesaRiskScore/RiskScore.aspx.

#cardiology

Reference:

1. McClelland RL, Jorgensen NW, Budoff M, et al. 10-Year Coronary Heart Disease Risk Prediction Using Coronary Artery Calcium and Traditional Risk Factors: Derivation in the MESA (Multi-Ethnic Study of Atherosclerosis) With Validation in the HNR (Heinz Nixdorf Recall) Study and the DHS (Dallas Heart Study). J Am Coll Cardiol 2015; 66:1643.

IV to PO morphine

 Q: What is an estimated IV to PO conversion ratio of Morphine?

Answer: 1:3

While converting intravenous (IV) to oral (PO) opioids two principles should be kept in mind 

1. Conservative estimates should be used.
2. The optimal dose should be found with judicious titration due to the fact that cross-tolerance equivalency is not established.

#pharmacology

Reference:

Calculating Conversations in Opioid Conversions 

url: https://www.fda.gov/media/150396/download (last accessed March 11, 2021)

CBC reading

Q: 47 years old African-American male is admitted to ICU with acute bleeding due to esophageal varices. Serial CBC shows, a parallel decrease in Hemoglobin (Hb) and Hematocrit (HCT) but an inverse increase in RBC count. What could be the underlying disease?

Answer: Thalassemia

In patients with anemia, Hb, HCT, and RBC count usually decrease in parallel except in patients with thalassemia. This is due to severe microcytosis.

The incidence of thalassemia is relatively high in the African-American population and suggests the underlying pathology of thalassemia.

#hematology

Reference:

Munkongdee T, Chen P, Winichagoon P, Fucharoen S, Paiboonsukwong K. Update in Laboratory Diagnosis of Thalassemia. Front Mol Biosci. 2020 May 27;7:74. doi: 10.3389/fmolb.2020.00074. PMID: 32671092; PMCID: PMC7326097.

Dialysis in TLS

Q: Which of the following is NOT an indication for early dialysis in patients with Tumor Lysis Syndrome (TLS)? (select one)

A) hyperkalemia

B) Hyperphosphatemia

C) hypercalcemia

D) High uric acid

Answer: C

The objective of this question is to highlight the low threshold of initiating dialysis in patients who develop TLS. This low threshold is due to two reasons:

1. Hyperkalemia occurs relatively fast in TLS due to rapid potassium release and can be fatal with superimposed oliguria. 

2. Rapid reduction of uric acid and phosphate levels is vital in preventing End-Stage Renal Disease (ESRD).

Usually, symptomatic hypocalcemia (not hypercalcemia) is a norm in TLS. This is due to hyperphosphatemia (choice C).

#nephrology

#oncology

References:

1. Cairo MS, Bishop M. Tumour lysis syndrome: new therapeutic strategies and classification. Br J Haematol 2004; 127:3.

2. Tan HK, Bellomo R, M'Pis DA, Ronco C. Phosphatemic control during acute renal failure: intermittent hemodialysis versus continuous hemodiafiltration. Int J Artif Organs 2001; 24:186.

Osborn wave

Q: 48 years old homeless male is brought to ED at Chicago downtown hospital with severe hypothermia. EKG was found to have a characteristic J point elevation (Osborn wave). J point elevation in hypothermia correlates with the degree of hypothermia?

A) Yes

B) No

Answer: A

Along with bradycardia hypothermia produces a classic J point elevation, known as Osborn wave. This elevation correlates with the degree of hypothermia. Osborn wave can be best seen from lead V2 to lead V5. Care should be taken to make sure that any other ST-segment elevation is not missed due to this wave. 

It is essential that a clinician personally evaluates all EKGs in hypothermia so as not to miss any cardiac ischemia findings (automatic machine readings may not be reliable).

Said that many other conditions can give similar EKG appearance such as early repolarization, hypercalcemia, and Brugada syndrome. Although suggestive of hypothermia, subarachnoid hemorrhage (SAH), and traumatic brain injury (TBI).

#cardiology

#hypothermia

References:

1. Doshi HH, Giudici MC. The EKG in hypothermia and hyperthermia. J Electrocardiol 2015; 48:203. 

2. Graham CA, McNaughton GW, Wyatt JP. The electrocardiogram in hypothermia. Wilderness Environ Med 2001; 12:232. 

3. Salinski EP, Worrilow CC. ST-segment elevation myocardial infarction vs. hypothermia-induced electrocardiographic changes: a case report and brief review of the literature. J Emerg Med 2014; 46:e107.

Causes of WE

Q: Describe few causes of Wernicke encephalopathy (WE) besides chronic alcoholism?

Answer: The objective of this question is to highlight the stereotyping of WE occurring only in patients with chronic alcoholism. About one-forth of patients with WE has a cause other ETOH abuse. There are many other causes of WE. Any or combination of following four factors of thiamine deficiency can cause WE.

1.  inadequate dietary intake
2. decreased gastrointestinal (GI) absorption, 
3. reduced liver storage, and 
4. impaired utilization

Some of the conditions beside chronic alcohol abuse which can cause WE are

• Anorexia nervosa 
• Poor diet
• Hyperemesis gravidarum
• GI pathology 
• Bariatric surgery
• Malignancy 
• Transplant
• Hemo or peritoneal dialysis
• AIDS
• Genetic disorder of thiamine metabolism 

#neurology

#vitamins

References:

1. Lindboe CF, Løberg EM. Wernicke's encephalopathy in non-alcoholics. An autopsy study. J Neurol Sci 1989; 90:125.

2. Sechi G, Serra A. Wernicke's encephalopathy: new clinical settings and recent advances in diagnosis and management. Lancet Neurol. 2007 May;6(5):442-55. doi: 10.1016/S1474-4422(07)70104-7. PMID: 17434099.

Cholestyramine in thyroid storm

Q: 24 years old female is admitted to ICU with thyroid storm. Endocrine service suggested adding cholestyramine. How does it help in thyroid storm?

Answer: By default, thyroid hormones are hepatically metabolized. They get conjugated with glucuronide and sulfate, and these conjugated products get excreted in bile. Free thyroid hormones are released in intestine and are reabsorbed. Cholestyramine is a bile acid sequestrant. It interrupts T3, T4 enterohepatic circulation and thus recycling of thyroid hormone. It is a valuable adjuvant treatment in thyroid storm, particularly in patients who are thionamides intolerant.

#endocrine

References:

1. Solomon BL, Wartofsky L, Burman KD. Adjunctive cholestyramine therapy for thyrotoxicosis. Clin Endocrinol (Oxf) 1993; 38:39. 

2. Kaykhaei MA, Shams M, Sadegholvad A, et al. Low doses of cholestyramine in the treatment of hyperthyroidism. Endocrine 2008; 34:52.

3. Tsai WC, Pei D, Wang TF, et al. The effect of combination therapy with propylthiouracil and cholestyramine in the treatment of Graves' hyperthyroidism. Clin Endocrinol (Oxf) 2005; 62:521.

COVID, cancer and DVT

 Q: Cancer patients who develop COVID-19 infection are more prone to develop thrombosis than non-cancer patients? (select one)

A) True

B) False

Answer: B

Although in general cancer patients are more at risk for developing Deep Venous Thromboses (DVTs) but fortunately, COVID-19 infection doesn't increase that risk, despite the hypercoagulability tendency of COVID-19. This applies to both arterial and venous thromboses. 

To date, there is no evidence that cancer patients with COVID-19 should be treated more aggressively for the prevention of thromboses.

#oncology

#COVID-19

#hematology

Reference:

Patell R, Bogue T, Bindal P, et al. Incidence of thrombosis and hemorrhage in hospitalized cancer patients with COVID-19. J Thromb Haemost 2020; 18:2349.

ARB and enteropathy

Q: 58 years old male with history of hypertension but stable on a single medicine for the last two years is admitted to ICU with worsening diarrhea, hypovolemia, and impending kidney failure. Which of the following anti-hypertensive is more prone to produce "sprue-like enteropathy"? (select one)

A) Irbesartan (Avapro)

B) Losartan (Cozaar)

C) Olmesartan (Benicar)

D) Valsartan (Diovan)

E) Candesartan (Atacand)

 Answer: C

  One of the popular angiotensin II receptor blockers (ARBs) olmesartan is associated with "sprue-like enteropathy". Although intestinal biopsy shows villous atrophy, though antibody testing for celiac disease stays negative. Diagnosis is based on rechallenging the drug, clinical symptoms, and intestinal biopsy. ACE inhibitors or other ARBs have not been implicated yet.

#pharmacology

#GI

References:

1. Ianiro G, Bibbò S, Montalto M, et al. Systematic review: Sprue-like enteropathy associated with olmesartan. Aliment Pharmacol Ther 2014; 40:16.

2. Basson M, Mezzarobba M, Weill A, et al. Severe intestinal malabsorption associated with olmesartan: a French nationwide observational cohort study. Gut 2016; 65:1664.

3. Talley NJ. Use of olmesartan for ≥ 1 year was associated with hospitalization for intestinal malabsorption. Ann Intern Med 2015; 163:JC13.

Sicca syndrome and sicca complex

Q: What is the difference between sicca syndrome and sicca complex? 

Answer: 

Sicca syndrome is a synonym for Sjögren's syndrome (SS). On the other hand, sicca complex refers to dryness of the eyes and mouth without specification to different etiologies, like about 40% of patients with active chronic hepatitis and 70% with primary biliary cirrhosis (PBC) have it.

Term sicca complex came from keratoconjunctivitis sicca which denotes the ocular findings of SS, and was coined by Swedish ophthalmologist Henrik Sjögren. Other terms used are dry eye syndrome and dysfunctional tear syndrome.

#rheumatology

References: 

1. Sjögren H. Zur Kenntnis der Keratoconjunctivitis sicca. Acta Ophthalomol 1933; 11(suppl II):1. 

2. Golding PL, Bown R, Mason AM, Taylor E. "Sicca complex" in liver disease. Br Med J. 1970 Nov 7;4(5731):340-2. doi: 10.1136/bmj.4.5731.340. PMID: 5472806; PMCID: PMC1819706. 

3. The definition and classification of dry eye disease: report of the Definition and Classification Subcommittee of the International Dry Eye WorkShop (2007). Ocul Surf 2007; 5:75.

Appendicitis in pregnancy

Q: 28 years old female who is 32 weeks pregnant is admitted to ICU with acute appendicitis. Cesarean delivery should be carried out with appendectomy?

A) True

B) False

Answer: B

Pregnant patients with acute appendicitis are treated more or less as in normal population. Pharmacy should be consulted if antibiotics are prescribed to avoid fetal toxicity. Appendectomy is curative in pregnancy. Relying solely on on antibiotic treatment is not appropriate.

Delaying surgery carries a high risk of perforation. Cesarean delivery (C-section) is rarely required. Risk of dehiscence or uterine perforation later in vaginal delivery is low if fascia is closed properly.

#ob-gyn

#surgical-critica-care

References:

1. Mazze RI, Källén B. Appendectomy during pregnancy: a Swedish registry study of 778 cases. Obstet Gynecol 1991; 77:835. 

2. Joo JI, Park HC, Kim MJ, Lee BH. Outcomes of Antibiotic Therapy for Uncomplicated Appendicitis in Pregnancy. Am J Med 2017; 130:1467. 

3. Silvestri MT, Pettker CM, Brousseau EC, et al. Morbidity of appendectomy and cholecystectomy in pregnant and nonpregnant women. Obstet Gynecol 2011; 118:1261. 

4.  McGory ML, Zingmond DS, Tillou A, et al. Negative appendectomy in pregnant women is associated with a substantial risk of fetal loss. J Am Coll Surg 2007; 205:534. Ito K, Ito H, Whang EE, 

5. Tavakkolizadeh A. Appendectomy in pregnancy: evaluation of the risks of a negative appendectomy. Am J Surg 2012; 203:145.

lopressor-coreg conversion

 Q: What's the conversion ratio of Metoprolol to Carvedilol?

Answer: About 4:1

#cardiology

#pharmacology

Reference;

Cohen-Solal A, Jacobson AF, Piña IL. Beta blocker dose and markers of sympathetic activation in heart failure patients: interrelationships and prognostic significance. ESC Heart Fail. 2017 Nov;4(4):499-506. doi: 10.1002/ehf2.12153. Epub 2017 Apr 19. PMID: 29154422; PMCID: PMC5695165.

oral Metronidazole failure in c-diff.

Q: What usually leads to failure of oral metronidazole in clostridioides difficile infection? 

Answer:Although not completely clear but it appears that oral metronidazole has a capacity to get well absorbed, which turns out to be a cause of failure! As colonic inflammation improves and metronidazole stool level decreases (due to increase gut absorption), treatment failure may ensues. 

In contrast, oral vancomycin or fidaxomicin is very poorly absorbed from the gut. Their stool drug level remains high leading to a better prospect of treatment in clostridioides difficile infection.

#GI

#ID

#pharmacology

References:

1. Musher DM, Aslam S, Logan N, et al. Relatively poor outcome after treatment of Clostridium difficile colitis with metronidazole. Clin Infect Dis 2005; 40:1586.

2. Hu MY, Maroo S, Kyne L, et al. A prospective study of risk factors and historical trends in metronidazole failure for Clostridium difficile infection. Clin Gastroenterol Hepatol 2008; 6:1354.

3. Bolton RP, Culshaw MA. Faecal metronidazole concentrations during oral and intravenous therapy for antibiotic associated colitis due to Clostridium difficile. Gut 1986; 27:1169.

4. Appaneal HJ, Caffrey AR, LaPlante KL. What Is the Role for Metronidazole in the Treatment of Clostridium difficile Infection? Results From a National Cohort Study of Veterans With Initial Mild Disease. Clin Infect Dis 2019; 69:1288.

Olanzapine in NV

Q: Olanzapine can be used in acute nausea and vomiting?

A) Yes

B) No

Answer: A

Olanzapine is a second-generation antipsychotic. It not only blocks serotonin 5-hydroxytryptamine (5-HT2) receptors but also dopamine D2 receptors. This property makes Olanzapine an attractive choice in both acute and delayed nausea and vomiting. Actually, a recent meta-analysis (2019) shows that olanzapine-containing regimens are most effective in preventing chemotherapy-induced nausea vomiting (CINV). 

A 5 mg dose is recommended to avoid the dangers of prolonged QTc and is found to be as effective as 10 mg.

#GI

#oncology

References:

1. Sutherland A, Naessens K, Plugge E, et al. Olanzapine for the prevention and treatment of cancer-related nausea and vomiting in adults. Cochrane Database Syst Rev 2018; 9:CD012555.

2. Yokoe T, Hayashida T, Nagayama A, et al. Effectiveness of Antiemetic Regimens for Highly Emetogenic Chemotherapy-Induced Nausea and Vomiting: A Systematic Review and Network Meta-Analysis. Oncologist 2019; 24:e347.

3. Navari RM, Qin R, Ruddy KJ, et al. Olanzapine for the Prevention of Chemotherapy-Induced Nausea and Vomiting. N Engl J Med 2016; 375:134.

4. Yanai T, Iwasa S, Hashimoto H, et al. A double-blind randomized phase II dose-finding study of olanzapine 10 mg or 5 mg for the prophylaxis of emesis induced by highly emetogenic cisplatin-based chemotherapy. Int J Clin Oncol 2018; 23:382.

5. Hashimoto H, Abe M, Tokuyama O, et al. Olanzapine 5 mg plus standard antiemetic therapy for the prevention of chemotherapy-induced nausea and vomiting (J-FORCE): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet Oncol 2020; 21:242.

5 Ds

Q: What are the 5 Ds in Medicine?

Answer: At all levels of medical care and preventions (primary, secondary, and tertiary), in general physicians strive to prevent 5 Ds:

• death
• disease
• disability
• discomfort
• dissatisfaction

Primary prevention: to keep the disease from occurring at all.

Secondary prevention: to detect disease early at the asymptomatic stage and prevent it from progressing.

Tertiary prevention: to prevent further deterioration and complications.

#general-concepts

References:

1. Prevention. In: Clinical Epidemiology: The Essentials, 6th ed, Fletcher G (Ed), Lippincott Williams and Wilkins 2020.

2. Grant S Fletcher, Evidence-based approach to prevention: UpTodate: Last updated: Feb 17, 2022. Link: https://www.uptodate.com/contents/evidence-based-approach-to-prevention

steroids in transplant surgery

Q: Methylprednisolone is usually given intraoperatively during lung transplantation. It should be given? (select one)

A) before the perfusion of graft

B) after the perfusion of graft

Answer: A

Immunosuppression is the most vital component in the success of transplantation. Some immunosuppressants are given preoperatively and some are perioperatively and are continued later on for a longer period of time for years. 

500 to 1000 mg of methylprednisolone is given in OR and preferably should be given before the perfusion of the graft. 

#transplantation

References:

1. Chandrashekaran S, Crow Pharm SA, Shah SZ, Arendt Pharm CJ, Kennedy CC. Immunosuppression for Lung Transplantation: Current and Future. Curr Transplant Rep. 2018 Sep;5(3):212-219. doi: 10.1007/s40472-018-0199-4. Epub 2018 Jul 13. PMID: 30740294; PMCID: PMC6366648.

2. Nelson J, Kincaide E, Schulte J, Hall R, Levine DJ. Immunosuppression in Lung Transplantation. Handb Exp Pharmacol. 2021 Nov 19. doi: 10.1007/164_2021_548. Epub ahead of print. PMID: 34796380.

fentanyl patch and heat

 Q: 78 years old male with metastatic esophageal cancer is admitted to ICU with urosepsis. The patient is on a chronic transdermal fentanyl patch from home and requested to continue it. 

Fever will __________ the systemic absorption? (select one)

A) increases

B) decreases

Answer: A

Transdermal fentanyl has some weak evidence to show reduced risk of constipation over other narcotics i.e., morphine patch. Also, it does not produce active metabolites. 

Said that any exposure of patch to heat such as fever, a heating pad, or warming blanket may increase the systemic fentanyl absorption, bearing the risk of respiratory depression.

#pharmacology

Reference:

Newshan G. Heat-related toxicity with the fentanyl transdermal patch. J Pain Symptom Manage. 1998 Nov;16(5):277-8. doi: 10.1016/s0885-3924(98)00100-6. PMID: 9846020.

CSF in carcinomatous meningitis

Q: The cerebrospinal fluid (CSF) pressure in leptomeningeal metastases is usually? (select one)

A) high

B) low

Answer: A

Brain is covered (from outside to inside) with three layers

• dura mater
• arachnoid mater
• pia mater

The arachnoid and the pia mater are collectively called leptomeninges. Whenever any tumor involves the leptomeninges, it is leptomeningeal metastases. It is also called meningeal carcinomatosis, carcinomatous meningitis, and neoplastic meningitis. 

In a patient with a history of tumor and clinical signs, a high opening pressure is almost always synonymous with leptomeningeal metastases. Other expected CSF findings are low glucose, high protein, lymphocytic pleocytosis, and positive cytology. Unfortunately, positive cytology is not always present.

#neurology

#oncology

#procedures

References:

1. Bönig L, Möhn N, Ahlbrecht J, Wurster U, Raab P, Puppe W, Sühs KW, Stangel M, Skripuletz T, Schwenkenbecher P. Leptomeningeal Metastasis: The Role of Cerebrospinal Fluid Diagnostics. Front Neurol. 2019 Aug 20;10:839. doi: 10.3389/fneur.2019.00839. PMID: 31481919; PMCID: PMC6710356.

2. Chamberlain MC. Leptomeningeal metastasis. Semin Neurol. 2010 Jul;30(3):236-44. doi: 10.1055/s-0030-1255220. Epub 2010 Jun 24. PMID: 20577930.

Emergent Cricothyroidotomy