procal

Q: All of the following can cause a false negative procalcitonin (procal) level EXCEPT? - select one

A) cystitis

B) abscesses

C) empyemas 

D) malaria

E) skin/soft tissue infections

Answer: D

Procal is great for antibiotic stewardship, but it should be used cautiously as many false positives and negatives may occur. It is mainly related to bacterial infections, but non-bacterial infections, like malaria or invasive candida infections, can also cause them to rise.

On the other hand, if a bacterial infection is contained in localized infections like tonsillitis, sinusitis, cystitis, uncomplicated skin/soft tissue infections, abscesses, or empyemas, it may not be elevated. This can cause a clinician to not initiate antibiotic treatment, which can have subsequent harmful consequences for the patient.

#lab-medicine

#ID

References:

1. Uzzan B, Izri A, Durand R, et al. Serum procalcitonin in uncomplicated falciparum malaria: a preliminary study. Travel Med Infect Dis 2006; 4:77.

2. Charles PE, Castro C, Ruiz-Santana S, et al. Serum procalcitonin levels in critically ill patients colonized with Candida spp: new clues for the early recognition of invasive candidiasis? Intensive Care Med 2009; 35:2146.

3. Pallin DJ, Bry L, Dwyer RC, et al. Toward an Objective Diagnostic Test for Bacterial Cellulitis. PLoS One 2016; 11:e0162947.

Unexpected allergic reaction

Q: 23 years old male with some undefined allergic reactions in the past was admitted to ICU with severe systemic allergic reaction after an insect bite, which required administration of an "epi injection." Which one blood test should be sent to rule out mast cell disorders (Mastocytosis)?

Answer: Tryptase level

This question aims to emphasize the typical outcome of regular insect bites. Systemic allergic reactions to insect bites are uncommon. Still, patients with mast cell disorders may develop severe systemic allergic reactions following insect bites or minor triggers for which severe reactions are unexpected.

During any such episode, serum total tryptase should be checked to establish the diagnosis of mastocytosis. Tryptase levels above 5-8 ng/mL are considered a risk. These patients, even though they may not have underlying systemic mastocytosis, are always at high risk for severe allergic reactions. Proper prevention and availability of an "epi-pen" can be a lifesaver. Patient should be referred to an allergist.

#allergy-immunology

References:

1. Reiter N, Reiter M, Altrichter S, et al. Anaphylaxis caused by mosquito allergy in systemic mastocytosis. Lancet 2013; 382:1380.

2. Ruëff F, Przybilla B, Biló MB, et al. Predictors of severe systemic anaphylactic reactions in patients with Hymenoptera venom allergy: importance of baseline serum tryptase-a study of the European Academy of Allergology and Clinical Immunology Interest Group on Insect Venom Hypersensitivity. J Allergy Clin Immunol 2009; 124:1047.

ICH after DAPT

Q: 57 years old male who has been recently started on Dual Anti-Platelet Therapy (DAPT) after his coronary artery stents is brought to emergency room (ER) with severe headache. CT scan showed intracranial hemorrhage (ICH). Platelet infusion should be ordered as bleeding probably happened due to DAPT.

A) True

B) False

Answer: B

Due to antiplatelet therapy, ICH does not require platelet transfusion. In fact, studies have shown that they can be harmful (see references #1 and #2).

Said that platelet transfusions may be given if clinician feels that it may help to reduce risks of postoperative bleeding in case patient is taken to the OR.

#surgery-critical-care

#hematology

#pharmacology

#neurology

#neuro-surgery

References:

1. Baharoglu MI, Cordonnier C, Al-Shahi Salman R, et al. Platelet transfusion versus standard care after acute stroke due to spontaneous cerebral haemorrhage associated with antiplatelet therapy (PATCH): a randomised, open-label, phase 3 trial. Lancet 2016; 387:2605.

2. Eilertsen H, Menon CS, Law ZK, et al. Haemostatic therapies for stroke due to acute, spontaneous intracerebral haemorrhage. Cochrane Database Syst Rev 2023; 10:CD005951.

3. Mayer SA, Brun NC, Begtrup K, et al. Efficacy and safety of recombinant activated factor VII for acute intracerebral hemorrhage. N Engl J Med 2008; 358:2127.

Wrong-site procedure

Q: Which procedure has the commonest wrong site error incidence?

Answer: A wrong-site nerve block 

Unfortunately, despite many written checklists, wrong-site surgery/procedure remains a leading and embarrassing complication in surgery. Although site marking based on imaging is the easiest to prevent, it remains one of the leading underlying misses.

A wrong site nerve block occurs in an estimated 0.53 to 5.07 per 10,000 regional blocks.

#surgical critical care

References:

1. Neily J, Mills PD, Eldridge N, et al. Incorrect surgical procedures within and outside of the operating room. Arch Surg 2009; 144:1028.

2. Devine J, Chutkan N, Norvell DC, Dettori JR. Avoiding wrong site surgery: a systematic review. Spine (Phila Pa 1976) 2010; 35:S28.

3. Deutsch ES, Yonash RA, Martin DE, et al. Wrong-site nerve blocks: A systematic literature review to guide principles for prevention. J Clin Anesth 2018; 46:101.

Tension PTX and mediastinal shift

Q: 28 years old 'tall, thin, lean man' walked into the emergency room (ER) with severe acute right-sided chest pain associated with shortness of breath (SOB). Chest X-ray showed complete spontaneous pneumothorax (PTX) with mediastinal shift to left side. Patient qualifies as having 'tension' pneumothorax due to mediastinal shift.

A) True

B) False

Answer: B

This question aims to emphasize that 'tension' pneumothorax is defined by PTX, causing hemodynamic instability. The mediastinal shift does not qualify PTX as 'tension.'

Another clue in the question is the patient walking in the ER. At least one study determined that the ability to walk freely around the emergency department can be used as a clue for the stability of the PTX (reference #2).

Tall, lean thin males are prone to develop primary PTX.

#pulmonary

References:

1. Brown SGA, Ball EL, Perrin K, et al. Conservative versus Interventional Treatment for Spontaneous Pneumothorax. N Engl J Med 2020; 382:405.

2. Kelly AM, Clooney M, Spontaneous Pneumothorax Australia Study Group. Deviation from published guidelines in the management of primary spontaneous pneumothorax in Australia. Intern Med J 2008; 38:64.

3. Simpson G, Vincent S, Ferns J. Spontaneous tension pneumothorax: what is it and does it exist? Intern Med J. 2012 Oct;42(10):1157-60. doi: 10.1111/j.1445-5994.2012.02910.x. PMID: 23227475.

Tanning in Addison's disease

Q: During a clinical exam for adrenal insufficiency, which 2 sites can easily be examined for the characteristic 'tanning'?

Answer: 

• skin creases (mostly palm) 
• buccal mucosa

Addison's disease (adrenal insufficiency) causes patchy and sometimes uniform skin tanning all over the body. Two characteristic sites of tanning to look for are skin creases (as of the palms) and the inside of the cheek (buccal mucosa). 

This tanning occurs due to increased production of melanocyte-stimulating hormone (MSH) and adrenocorticotropic hormone (ACTH) when the adrenal glands fail and cortisol production decreases. MSH stimulates melanocytes to produce more pigment, especially in areas that are mostly exposed to sunlight and pressure, such as the knuckles, knees, and armpits. The slang used for such tanning is either "bronzing or bronze man." It gives the patients a very peculiar look compared to the individuals around.

#endocrinology

#physical-exam

References:

1. Tong CV, Ooi XY. Addison's disease presenting with hyperpigmentation. BMJ Case Rep. 2021 Aug 17;14(8):e245610. doi: 10.1136/bcr-2021-245610. PMID: 34404673; PMCID: PMC8375727.

2. Munir S, Quintanilla Rodriguez BS, Waseem M. Addison Disease. 2024 Jan 30. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan–. PMID: 28723023.

Platelet transfusion

Q: How long does it take for platelet count to rise post-transfusion? - select one

A) 10 minutes

B) 20 minutes

C) 30 minutes

Answer: A

Although transfusing only apheresis platelets is now more conventional than whole body-derived (WBD) platelets, the effect is almost comparable.

Four to six WBD platelets or one apheresis unit, which is standard to transfuse as prophylaxis to prevent bleeding due to thrombocytopenia, provides about 3 to 4 × 1011unit platelets. This platelet dose transfusion approximately raises platelet count by 30,000/microL within 10 minutes of infusion. 

For prophylaxis, one-time transfusion per day is enough. The Association for the Advancement of Blood and Biotherapies (AABB) states, "Greater doses are not more effective, and lower doses are equally effective."

#hematology

#transfusion-medicine

References:

1. Slichter SJ, Kaufman RM, Assmann SF, et al. Dose of prophylactic platelet transfusions and prevention of hemorrhage. N Engl J Med 2010; 362:600.

2. Kaufman RM, Djulbegovic B, Gernsheimer T, et al. Platelet transfusion: a clinical practice guideline from the AABB. Ann Intern Med 2015; 162:205.

human infectious disease with highest case fatality rate

Q: Which of the human infectious diseases carry the highest case fatality rate? - select one

A) HIV

B) Polio

C) Tuberculosis (TB)

D) Rabies

E) Malaria

Answer: D

Unfortunately, per the World Health Organization (WHO) report, Rabies has a fatality rate of almost 100% in humans and animals once symptoms appear. It's considered the world's deadliest virus. Said that simultaneously, it is 100% preventable through vaccination and precautions.

Though TB kills about 1.3 million people worldwide each year globally, its fatality rate is not 100% and is curable. Malaria is 100% curable after symptoms appear, and since significant progress has been made in HIV treatment, many patients have lived almost full of their lives.

#ID

#epidemiology

References:

1. WHO report: Link: https://www.who.int/news-room/fact-sheets/detail/rabies (last accessed August 11, 2024)

2. Trickey A, Sabin CA, $ et al.: Life expectancy after 2015 of adults with HIV on long-term antiretroviral therapy in Europe and North America: a collaborative analysis of cohort studies. Lancet HIV. 2023 May;10(5):e295-e307. doi: 10.1016/S2352-3018(23)00028-0. Epub 2023 Mar 20. PMID: 36958365; PMCID: PMC10288029.

3. Bukundi EM, Mhimbira F, Kishimba R, Kondo Z, Moshiro C. Mortality and associated factors among adult patients on tuberculosis treatment in Tanzania: A retrospective cohort study. J Clin Tuberc Other Mycobact Dis. 2021 Jul 18;24:100263. doi: 10.1016/j.jctube.2021.100263. PMID: 34355068; PMCID: PMC8322306.

Bulla

Q: 59 years old male is admitted to ICU with exacerbation of emphysema. The chest X-ray by radiology says, "There is a large bulla at the right upper lobe." How is bulla exactly defined?

Answer: Bulla refers to a region of focal lucency of air-filled space that is >1 cm in diameter, bounded by a thin wall of <1 mm. Bullae can be isolated or adjacent and vary in size. They are typically larger at the apices. 

                                                                                                          

                                                                                                          

#pulmonary

                                                                                                          

 References:

                                                                                                                              

1. Goldberg C, Carey KE. Bullous lung disease. West J Emerg Med. 2013 Sep;14(5):450-1. doi: 10.5811/westjem.2013.3.16276. PMID: 24106540; PMCID: PMC3789906.

                                                                                                                              

2. Siddiqui NA, Mansour MK, Nookala V. Bullous Emphysema. [Updated 2023 Jun 26]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK537243/

NIRA

Q; 17 years old male, a foster home resident, is admitted to ICU with severe diarrhea and hypotension. While evaluating patient, GI service ordered NIRA. What is the advantage of Near infrared reflectance Analysis (NIRA) over other tests for severe malabsorption?

Answer: Though NIRA is less frequently used in USA than in other parts of the world, it almost accurately and quickly measures all the three dietary components, i.e., fecal fat, nitrogen, and carbohydrates, from a single sample. It does not require 72-hour fecal fat collection. It is an excellent tool for diagnosing malabsorption.

#GI

#laboratory-medicine

References:

1. Neumeister V, Henker J, Kaltenborn G, et al. Simultaneous determination of fecal fat, nitrogen, and water by near-infrared reflectance spectroscopy. J Pediatr Gastroenterol Nutr 1997; 25:388.

2. Stein J, Purschian B, Zeuzem S, et al. Quantification of fecal carbohydrates by near-infrared reflectance analysis. Clin Chem 1996; 42:309.

3.Bekers O, Postma C, Fischer JC, et al. Faecal nitrogen determination by near-infrared spectroscopy. Eur J Clin Chem Clin Biochem 1996; 34:561.

CO and oxyhemoglobin dissociation curve

Q:  Carbon monoxide (CO) moves oxyhemoglobin dissociation curve to - select one

A) left

B) right

Answer: A

Carbon monoxide is a colorless and odorless gas with an affinity for hemoglobin more than 200 times higher than oxygen. CO poisoning must be ruled out in all patients after inhalation injury or fires by documented blood carboxyhemoglobin level.

Pulse oximetry cannot rule out carbon monoxide poisoning. PulseOx does not differentiate carboxyhemoglobin from oxyhemoglobin. Carboxyhemoglobin levels should be measured with CO-oximetry, preferably on the arterial blood.

Carboxyhemoglobin shifts the oxyhemoglobin dissociation curve to the left, impairing the release of oxygen at the tissues and utilization of oxygen in mitochondria, causing tissue hypoxia.

#hematology

#toxicity

References:

1. Rehberg S, Maybauer MO, Enkhbaatar P, et al. Pathophysiology, management and treatment of smoke inhalation injury. Expert Rev Respir Med 2009; 3:283.

2. Prien T, Traber DL. Toxic smoke compounds and inhalation injury--a review. Burns Incl Therm Inj 1988; 14:451.

3. Blumenthal I. Carbon monoxide poisoning. J R Soc Med. 2001 Jun;94(6):270-2. doi: 10.1177/014107680109400604. PMID: 11387414; PMCID: PMC1281520.

Procal in immunocompromised patients

Q: Procalcitonin level may not rise in patients with immunocompromised states.

A) True

B) False

Answer: B

Contrary to conventional belief, Procalcitonin production is NOT impaired in immunocompromised states. This includes

• neutropenia
• corticosteroids treatment
• bone marrow transplantation
• solid organ transplantation, and
• HIV infection 

#ID

#lab-medicine

References:

1.von Lilienfeld-Toal M, Dietrich MP, Glasmacher A, et al. Markers of bacteremia in febrile neutropenic patients with hematological malignancies: procalcitonin and IL-6 are more reliable than C-reactive protein. Eur J Clin Microbiol Infect Dis 2004; 23:539.

2. Koya J, Nannya Y, Ichikawa M, Kurokawa M. The clinical role of procalcitonin in hematopoietic SCT. Bone Marrow Transplant 2012; 47:1326.

3. Perren A, Cerutti B, Lepori M, et al. Influence of steroids on procalcitonin and C-reactive protein in patients with COPD and community-acquired pneumonia. Infection 2008; 36:163.

4. Tokman S, Barnett CF, Jarlsberg LG, et al. Procalcitonin predicts mortality in HIV-infected Ugandan adults with lower respiratory tract infections. Respirology 2014; 19:382.

Homonymous hemianopia

Q: Homonymous hemianopia is a visual field defect involving? - select one

A) right or the left half of one eye

B) two right or two left halves of both eyes

Answer: B

The terminology Homonymous hemianopia can be misleading, but if read properly - hemi followed by homo - in the name explains that it is a visual field defect involving either the two right or the two left halves of the visual fields of both eyes. It is due to lesions of the retrochiasmal visual pathways, i.e., lesions of the optic tract, the lateral geniculate nucleus, the optic radiations, and the cerebral visual (occipital) cortex.

#opthalmology

#neurology

References:

1. Levin LA. Topical diagnosis of chiasmal and retrochiasmal disorders. In: Walsh and Hoyt Clinical Neuro-ophthalmology, 6th ed, Miller NR, Newman NJ, Biousse V, Kerrison JB (Eds), Williams & Wilkins, Baltimore 2005. p.503.

2. Trobe JD. Visual fields. In: The Neurology of Vision, Trobe JD (Ed), Oxford, Oxford 2001. p.109.

3. Newman NJ, Galetta SL, Biousse V, et al. Disorder of vision. Continuum: Lifelong learning in Neurology. Neuroophthalmology 2003; 9:11.

ECT Rx in depression

Q: In major severe depression, electroconvulsive therapy (ECT) is the last resort in therapy, but its effectiveness lies in no further relapse.

A) True

B) False

Answer: B

Although electroconvulsive therapy (ECT) is an effective treatment for severe major depression, unfortunately, the relapse rate is high. Also, it is not very popular due to social stigma, safety risks, adverse effects, and logistical constraints. 

#psychiatry

#procedure

References:

1. UK ECT Review Group. Efficacy and safety of electroconvulsive therapy in depressive disorders: a systematic review and meta-analysis. Lancet 2003; 361:799.

2.  Pagnin D, de Queiroz V, Pini S, Cassano GB. Efficacy of ECT in depression: a meta-analytic review. J ECT 2004; 20:13.

3. Kellner CH, Knapp RG, Petrides G, et al. Continuation electroconvulsive therapy vs pharmacotherapy for relapse prevention in major depression: a multisite study from the Consortium for Research in Electroconvulsive Therapy (CORE). Arch Gen Psychiatry 2006; 63:1337.

Seizures in Hypomagnesemia

Q; At what serum level of Magnesium (mg) does the risk of acute symptomatic seizures escalate? - select one

A) 0.8 mEq/L

B) 1.2 mEq/L

C0 1.8 mEq/L

Answer: A

Few electrolytes and metabolite abnormalities are more prone to cause acute symptomatic seizures. Distinguished ones are:

• Hypoglycemia
• Hyperglycemia 
• Hyponatremia
• Hypocalcemia
• Hypomagnesemia

Mg below 0.8 mEq/L may cause irritability, agitation, confusion, myoclonus, tetany, and convulsions. Seizures in hypomagnesemia are usually accompanied by hypocalcemia. 

#electrolytes

#neurology

References:

1. Riggs JE. Neurologic manifestations of electrolyte disturbances. Neurol Clin 2002; 20:227.

2. Chen BB, Prasad C, Kobrzynski M, Campbell C, Filler G. Seizures Related to Hypomagnesemia: A Case Series and Review of the Literature. Child Neurol Open. 2016 Oct 27;3:2329048X16674834. doi: 10.1177/2329048X16674834. PMID: 28503619; PMCID: PMC5417264.

Splenic rupture in infectious mononucleosis

Q; 21 years old male is brought from a football game due to severe left abdominal pain. Patient was recently diagnosed with infectious mononucleosis. Workup showed a ruptured spleen. After the diagnosis of infectious mononucleosis, how long does the risk of splenic rupture persist?

Answer: About eight weeks

Splenomegaly after infectious mononucleosis carries a relatively increased risk of splenic rupture. This risk may persist for up to eight weeks after the onset of symptoms. The first three weeks carry the highest risk.

Ultrasound can be performed, though not required to document the resolution of splenomegaly.

#GI

#surgical-critical-care

References:

1. Ali J. Spontaneous rupture of the spleen in patients with infectious mononucleosis. Can J Surg 1993; 36:49.

2. Bartlett A, Williams R, Hilton M. Splenic rupture in infectious mononucleosis: A systematic review of published case reports. Injury 2016; 47:531.

PH in pleural fluid

Q; 72 years old male is admitted to ICU with fever, right-sided pleuritic chest pain, cough, and low-grade fever. Patient continues to require low-dose pressor in Emergency Room (ER) and is admitted to ICU. On Chest-X-ray (CXR) parapneumonic effusion is suspected due to history, symptoms and presence of infiltrates on CXR. What's the ideal way of drawing pleural PH? - select one

A) into a pediatric venous blood draw tube

B) into an arterial blood gas syringe

Answer: B

In suspected parapneumonic effusion or empyema, pleural fluid for pH should be drawn directly from the pleural space. Ideally, it should be drawn into an arterial blood gas (ABG) syringe. It should be placed immediately on ice and measured in a blood gas analyzer within one hour. It is rather a delicate draw and transport! Mixing pleural fluid with air, lidocaine, or excess heparin can alter the measured pH. Care should be taken particularly for lidocaine, as it can still be present in good amounts in skin, subcutaneous tissue, and underlying structures after local anesthetic application.

#procedures

#pulmonary

References:

1. Cheng DS, Rodriguez RM, Rogers J, et al. Comparison of pleural fluid pH values obtained using blood gas machine, pH meter, and pH indicator strip. Chest 1998; 114:1368.

2. Bowling M, Lenz P, Chatterjee A, et al. Perception versus reality: the measuring of pleural fluid pH in the United States. Respiration 2012; 83:316.

3. Rahman NM, Mishra EK, Davies HE, et al. Clinically important factors influencing the diagnostic measurement of pleural fluid pH and glucose. Am J Respir Crit Care Med 2008; 178:483.

Cannabis toxicity

Q: Acute cannabis intoxication may cause all of the following EXCEPT? - select one

A) Tachycardia

B) Conjunctival injection

C) Dry mouth

D) Slurred speech

E) Bronchodilatation

Answer: E

The objective of this question is to highlight the fact that cannabis/marijuana use may lead to acute exacerbations of asthma. Patients who have issues with bronchospasm and use cannabis may have poor symptom control. Other symptoms can be ataxia, hyperkinesis, seizures, lethargy, hyperemesis, dysphoria, and agitation.

Pneumothorax and pneumomediastinum are also reported when the user tends to do deep inhalation.

#toxicity

#pulmonary

References:

1. Ashton CH. Pharmacology and effects of cannabis: a brief review. Br J Psychiatry 2001; 178:101.

2. Tashkin DP. Effects of marijuana smoking on the lung. Ann Am Thorac Soc 2013; 10:239.

3. Noble MJ, Hedberg K, Hendrickson RG. Acute cannabis toxicity. Clin Toxicol (Phila). 2019 Aug;57(8):735-742. doi: 10.1080/15563650.2018.1548708. Epub 2019 Jan 24. PMID: 30676820.

4. Caponnetto P, Auditore R, Russo C, et al. "Dangerous relationships": asthma and substance abuse. J Addict Dis 2013; 32:158.

PCO2 and hypothermia

Q: 42 years old homeless gentleman is admitted to the ICU after a snowstorm in Illinois with hypothermia of 33°C. Patient is intubated. Central arterial lines are placed. Arterial Blood Gas (ABG) was sent. The actual PaCO2 of the patient should be considered _____________ than the value reported by blood gas machine? (select one)

A) higher

B) lower

Answer: B

In hypothermia, patient's actual PaCO2 should be considered lower than the value reported by blood gas machine. When a patient's core temperature is 33°C, the patient's actual PaCO2 may be 6-7 mmHg lower than the value reported by blood gas machine. It is recommended that slightly higher PaCO2 values be targeted in hypothermic patients. Unintended hyperventilation may cause cerebral vasoconstriction.

Although the quest to find a proper formula to determine actual PH depending on degree of hypothermia has been ongoing for six decades, no exact formula can be trusted with full confidence.

#ventilators

#acid-base

#hypothermia

References:

1. Sitzwohl C, Kettner SC, Reinprecht A, et al. The arterial to end-tidal carbon dioxide gradient increases with uncorrected but not with temperature-corrected PaCO2 determination during mild to moderate hypothermia. Anesth Analg 1998; 86:1131.

2. AUSTIN WH, LACOMBE EH, RAND PW. PH-TEMPERATURE CONVERSION FACTORS AND PCO2 FACTORS FOR HYPOTHERMIA. J Appl Physiol. 1964 Sep;19:893-6. doi: 10.1152/jappl.1964.19.5.893. PMID: 14207740.

3. Kofstad J. Blood gases and hypothermia: some theoretical and practical considerations. Scand J Clin Lab Invest Suppl. 1996;224:21-6. doi: 10.3109/00365519609088622. PMID: 8865418.

4. Chaney B, Emmady PD. Blood Gas Temperature Correction. [Updated 2023 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK557769/

CAC and CHD

Q: All of the following are associated with the early development of Coronary Heart Disease (CHD) after a positive Coronary Artery Calcium Score (CAC). Comparing all of the following, which is considered a relatively lesser risk factor for CHD to assess via CAC? - select one

A) diabetes 

B) smoking

C) hypertension

D) dyslipidemia

E) family history

Answer: A

"Calcium Scoring" has gained immense popularity in predicting coronary artery disease in recent years. In normal individuals, a 10-year atherosclerotic cardiovascular disease (ASCVD) risk is determined depending on the CAC score. However, patients with hypertension, dyslipidemia, and family history can develop the disease within 3.3 to 4.3 years of a positive CAC score.

Patients with diabetes though also develop CHD early, but it takes about 6.4 years after positive CAC. Males with diabetes should be checked within 35-38 years, and females between 49-52 years - for CAC scoring.

Generally, for a normal individual without risk factors, it should be done between 41-44 years in males and 56-60 years in females.

#cardiology

Reference:

Erbel R, Möhlenkamp S, Moebus S, et al. Coronary risk stratification, discrimination, and reclassification improvement based on quantification of subclinical coronary atherosclerosis: the Heinz Nixdorf Recall study. J Am Coll Cardiol 2010; 56:1397.

acholic stool

Q: 58 years old male is admitted to ICU from free standing Emergency Room (ER) in the community with severe dehydration and abdominal pain. CT scan of abdomen could not be performed as the machine was broken in ER. Patient required fluid resuscitation, pressors, and placement of an Arterial line. Patient reported loss of weight in the last six months and acholic stool. What could be the first concern?

Answer: Pancreatic cancer

Acholic (not alcoholic) stool is a clay-colored or pale stool, i.e., stool without a normal yellow-brown color. This shows a lack of bilirubin. The breakdown products of bilirubin, urobilin, and stercobilin give stool its brown color. Although it sounds simple, many clinicians have failed to identify it. In modern digital days, mobile phone applications using a phone camera are available to identify this important clinical sign. In pediatric populations, biliary atresia is a common cause, and early proper identification can be helpful.

The two major causes of symptomatic acholic stool, particularly in adults, are:

1. viral hepatitis 

2. Pancreatic cancer

With prolonged abdominal pain and loss of weight, pancreatic cancer is on top of the list of differential diagnoses. This is due to near-complete common bile duct obstruction from cancer of pancreatic head or the duodenal ampulla. Many times, it can be a presenting symptom.

The acholic stool can be transient in normal people due to diet or different intakes, such as large amounts of the active ingredient in antacids, which can cause pale stools.

#hepatology

#GI

#oncology

References:

1. De La Cruz MS, Young AP, Ruffin MT. Diagnosis and management of pancreatic cancer. Am Fam Physician. 2014 Apr 15;89(8):626-32. PMID: 24784121.

2. Franciscovich A, Vaidya D, Doyle J, Bolinger J, Capdevila M, Rice M, Hancock L, Mahr T, Mogul DB. PoopMD, a Mobile Health Application, Accurately Identifies Infant Acholic Stools. PLoS One. 2015 Jul 29;10(7):e0132270. doi: 10.1371/journal.pone.0132270. PMID: 26221719; PMCID: PMC4519295.

CKD, CKD-MBD and renal osteodystrophy

Q: What's the difference between Chronic kidney disease (CKD), chronic kidney disease-mineral and bone disorder (CKD-MBD), and "renal osteodystrophy"?

Answer:

Kidney Disease: Improving Global Outcomes (KDIGO) work group in 2006 recommended expanding the term chronic kidney disease (CKD) to chronic kidney disease-mineral and bone disorder (CKD-MBD) -when all three components are present, i.e.,

• Abnormalities of calcium, phosphorus, parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23), and vitamin D metabolism
• Abnormalities in bone turnover, mineralization, volume linear growth, or strength
• Extraskeletal calcification

This is because as CKD advances, it involves mineral and bone metabolism disorders, manifested by either one or a combination of the above three components.

"Renal osteodystrophy" should be used exclusively to define alterations in bone morphology associated with CKD based upon bone biopsy, and it is only one component of the bone abnormalities of CKD-MBD. Further, depending on bone biopsy, it can be sub-classified as high-turnover, low-turnover, or mixed-bone disease. It is important to note that skeletal disorders that may occur in patients with CKD, like osteoporosis and bone cysts due to dialysis-related amyloidosis, are not included in the term renal osteodystrophy.

#nephrology

#metabolism

#wlectrolytes

#bone-disorders

References:

1. Moe S, Drüeke T, Cunningham J, et al. Definition, evaluation, and classification of renal osteodystrophy: a position statement from Kidney Disease: Improving Global Outcomes (KDIGO). Kidney Int 2006; 69:1945.

2. Kidney Disease: Improving Global Outcomes (KDIGO) CKD-MBD Update Work Group. KDIGO 2017 Clinical Practice Guideline Update for the Diagnosis, Evaluation, Prevention, and Treatment of Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD). Kidney Int Suppl 2017; 7:1.

3. Pazianas M, Miller PD. Osteoporosis and Chronic Kidney Disease-Mineral and Bone Disorder (CKD-MBD): Back to Basics. Am J Kidney Dis 2021; 78:582.

Amiodarone and Eye

Q: 62 years old male with known history of atrial fibrillation and is on chronic amiodarone for many years admitted to ICU with community-acquired pneumonia. A medical student reported finding the corneal ring. Finding of corneal microdeposits is usually a sign of underlying Amiodarone toxicity?

A) True

B) False

Answer: B

Corneal microdeposits are common in long-term amiodarone therapy. Although they are dose-dependent and cause mild symptoms such as colored rings around lights, particularly at night, photophobia, and blurred vision, they are not a warning sign. They rarely affect visual acuity.

In fact, if visual acuity is affected, other causes should be ruled out first, such as change in refractive correction, progression of age-related cataracts, or increased intraocular pressure. Amiodarone can be reduced or discontinued depending on patient's preference and clinical judgment. It should be noted that Amiodarone itself can cause or worsen the cataract (reference #3).

Corneal microdeposits are usually present with lenticular opacities. They are caused by the lacrimal gland secreting amiodarone, which accumulates on corneal surface. The microdeposit appears as a brownish whorl at the juncture of lower one-third and upper two-thirds of the cornea and has been called cat's whiskers.

It gets resolve after few months of drug withdrawal.

#pharmacology

#opthalmology

#cardiology

References:

1. Mäntyjärvi M, Tuppurainen K, Ikäheimo K. Ocular side effects of amiodarone. Surv Ophthalmol 1998; 42:360.

2. Frings A, Schargus M. Recovery From Amiodarone-Induced Cornea Verticillata by Application of Topical Heparin. Cornea. 2017 Nov;36(11):1419-1422. doi: 10.1097/ICO.0000000000001306. PMID: 28834813.

3. Flach AJ, Dolan BJ. Progression of amiodarone induced cataracts. Doc Ophthalmol 1993; 83:323.

"double set-up" RSI

Q: What is a "double set-up" rapid sequence intubation (RSI)?

Answer: Simultaneously preparing video laryngoscope and surgical airway backup 

If difficult intubation is anticipated, as in severe anaphylaxis, there may not be time to call for surgical backup. Even a single failed attempt at intubation can distort the anatomy and close the vocal cords to the point where nothing can be viewed. 

Keeping all equipment simultaneously ready at the bedside for emergent cricothyroidotomy/tracheostomy is prudent.

#procedures

Reference:

1. Ahmed A, Azim A. Difficult tracheal intubation in critically ill. J Intensive Care. 2018 Aug 13;6:49. doi: 10.1186/s40560-018-0318-4. PMID: 30123510; PMCID: PMC6090786.

colonic ischemia after CPB

Q: Name a few risk factors that may induce colonic ischemia after cardiopulmonary bypass?

Answer:

Although colonic ischemia is rare (0.2 percent) after cardiopulmonary bypass, if it occurs, it is usually fatal (85 percent). A few risk factors are:

• old age
• end-stage renal disease (ESRD)
• valve surgery
• emergency bypass surgery
• low postoperative cardiac output 
• Long bypass times
• an intra-aortic balloon pump 

The underlying etiology is the low flow state of bypass perfusion and the exposure of the patient's blood to foreign surfaces, which leads to hypercoagulability, microemboli, alterations in cells and proteins, the release of vasoactive substances, and activation of the complement cascade. 

#surgical-critical-care

#cardiology

#procedure

References:

1. Fitzgerald T, Kim D, Karakozis S, et al. Visceral ischemia after cardiopulmonary bypass. Am Surg 2000; 66:623.

2. Allen KB, Salam AA, Lumsden AB. Acute mesenteric ischemia after cardiopulmonary bypass. J Vasc Surg 1992; 16:391.

3. Zacharias A, Schwann TA, Parenteau GL, et al. Predictors of gastrointestinal complications in cardiac surgery. Tex Heart Inst J 2000; 27:93.

medication reconciliation

Q: The medication reconciliation process includes all of the following steps EXCEPT? (select one)

A) Verification 

B) Clarification

C) Reconciliation

D) Notification

Answer: D

Adverse Drug Events (ADEs) can be decreased by a proper process of medication reconciliation. It has three steps:

1. Verification – Reviewing the patient's medication history and developing an accurate list of medications.

2. Clarification – Ensure appropriate current medications and their doses.

3. Reconciliation—Identify discrepancies between medication ordered for patients and those on the list, make appropriate changes to orders, document any changes, and communicate the updated list to next provider within or outside the hospital. Patients should also be provided written information on the medications when discharged from hospital.

Putting out notifications may become a public process and may cause privacy violations.

#pharmacology

Reference:

1. Greenwald JL, Halasyamani L, Greene J, et al. Making inpatient medication reconciliation patient centered, clinically relevant and implementable: a consensus statement on key principles and necessary first steps. J Hosp Med 2010; 5:477.

Markers in IBD

Q; Which stool marker assesses intestinal inflammation in Inflammatory Bowel Disease (IBD)? - select one

A) CRP

B) ESR

C) calprotectin 

Answer: C

C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) are serum markers that assess systemic inflammation.

The stool markers to assess intestinal inflammation are 

• fecal calprotectin 
• fecal lactoferrin 

Fecal calprotectin value of less than 50 mcg/g indicates that the mucosal disease likely remains in remission. Fecal lactoferrin is less commonly used.

#GI

References:

1. Patel A, Panchal H, Dubinsky MC. Fecal Calprotectin Levels Predict Histological Healing in Ulcerative Colitis. Inflamm Bowel Dis 2017; 23:1600.

2. Kawashima K, Ishihara S, Yuki T, et al. Fecal Calprotectin More Accurately Predicts Endoscopic Remission of Crohn's Disease than Serological Biomarkers Evaluated Using Balloon-assisted Enteroscopy. Inflamm Bowel Dis 2017; 23:2027.

3. D'Haens G, Ferrante M, Vermeire S, et al. Fecal calprotectin is a surrogate marker for endoscopic lesions in inflammatory bowel disease. Inflamm Bowel Dis 2012; 18:2218.

4. Menees SB, Powell C, Kurlander J, et al. A meta-analysis of the utility of C-reactive protein, erythrocyte sedimentation rate, fecal calprotectin, and fecal lactoferrin to exclude inflammatory bowel disease in adults with IBS. Am J Gastroenterol 2015; 110:444.

5. Monteiro S, Dias de Castro F, Leite S, et al. Low fecal calprotectin predicts clinical remission in Crohn's disease patients: the simple answer to a challenging question. Scand J Gastroenterol 2019; 54:49.

ASA and Preeclampsia

Q: Which Aspirin is recommended in high to moderate-risk preeclampsia? (select one)

A) low dose

B) high dose

Answer: A

Low-dose aspirin (ASA) is found to reduce the frequency of preeclampsia and many adverse pregnancy outcomes, such as preterm birth and growth restriction, by 10-20% when taken by patients at moderate to high risk of the disease. Low-dose ASA has an excellent maternal/fetal safety profile. 

Aspirin is recommended on the assumption that preeclampsia is associated with increased platelet turnover and increased platelet-derived thromboxane levels.

It should be noted that as opposed to high-dose aspirin therapy, low-dose aspirin (up to 150 mg/day) diminishes platelet thromboxane synthesis while maintaining vascular wall prostacyclin synthesis. Thromboxane promotes platelet aggregation and arterial constriction, whereas prostacyclin inhibits platelet aggregation and promotes vasodilatation. It also helps by modulating inflammation, which is exaggerated in patients with preeclampsia.

The American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine support the USPSTF guideline criteria for the prevention of preeclampsia. Low-dose aspirin (81 mg/day) prophylaxis is recommended in women at high risk of preeclampsia and should be initiated between 12 weeks and 28 weeks of gestation (optimally before 16 weeks) and continued daily until delivery. Women receiving medically indicated low-dose aspirin for other established medical indications before 12–28 weeks may continue with low-dose aspirin treatment. 

High-dose ASA does not provide any added benefit but increases the rate of bleeding and related complications.

#ob-gyn

References:

1. Dekker GA, Sibai BM. Low-dose aspirin in the prevention of preeclampsia and fetal growth retardation: rationale, mechanisms, and clinical trials. Am J Obstet Gynecol 1993; 168:214.

2. Cadavid AP. Aspirin: The Mechanism of Action Revisited in the Context of Pregnancy Complications. Front Immunol 2017; 8:261.

dehydration versus volume depletion

Q: What's the difference between dehydration and hypovolemia?

Answer:

Dehydration is due to Water depletion and usually leads to hypernatremia

Hypovolemia is due to loss of both salt and water.

#electrolytes

Reference:

Mange K, Matsuura D, Cizman B, et al. Language guiding therapy: the case of dehydration versus volume depletion. Ann Intern Med 1997; 127:848.

Agoraphobia

Q: 22 year old male admitted to ICU with suicidal ideation is now ready to get discharged to home with his family. Patient suddenly develops chills, sweating, tachycardia, shortness of breath, chest pain, and dizziness. Psych service was present in the ICU while writing his discharge orders. Patient gets diagnosed with Agoraphobia. What is Agoraphobia?

Answer: Agoraphobia is a fear, anxiety, or avoidance of situations where escape might be difficult in the event of developing panic-like or other embarrassing symptoms. It is important to note that Agoraphobia is classified as a separate disorder in the DSM-5-TR and is diagnosed independently of panic disorder. 

The two objectives attempted in the above questions are:

1. Patients who develop frequent and high levels of such attacks and agoraphobia should be watched closely for suicidal attempts.

2. Chills (used as a distractor in this question) can occur in panic attacks, as high muscular and metabolic demands may cause the sensation of heat and chills.

#psychiatry

References:

1. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision, American Psychiatric Association, Washington, D.C. 2022.

2. Kessler RC, Chiu WT, Jin R, et al. The epidemiology of panic attacks, panic disorder, and agoraphobia in the National Comorbidity Survey Replication. Arch Gen Psychiatry 2006; 63:415.

3. Wittchen HU, Gloster AT, Beesdo-Baum K, et al. Agoraphobia: a review of the diagnostic classificatory position and criteria. Depress Anxiety 2010; 27:113.