CVP and HJR

Q: In patients with significant tricuspid regurgitation (TR), the pulsatility of the liver may correspond to which part of central venous pressure (CVP)? 

A) a waves 
B) c waves 
C) v waves 
D) x descent 
E) y descent 


 Answer: C (v waves)

 Hepatojugular reflux is an excellent physical sign. Primarily it helps to differentiate cardiac causes of hepatic insufficiency from primary hepatic parenchymal diseases. In patients with significant TR, the liver is usually pulsatile and correspond with pre-systole pulsation i.e. v wave on CVP tracing. And, if this liver pulsatility is lost, it signifies cardiac cirrhosis.

#physical-exam
#cardiology
#hepatology


Reference:

Ma TS, Bozkurt B, Paniagua D, Kar B, Ramasubbu K, Rothe CF. Central venous pressure and pulmonary capillary wedge pressure: fresh clinical perspectives from a new model of discordant and concordant heart failure. Tex Heart Inst J. 2011; 38(6):627-38.

Acute alcohol myopathy

Q: 54 year old male is admitted to ICU with acute myopathy, rhabdomyolysis, and acute renal failure during his acute binge drinking phase. Which body muscles are most prone to be involved in acute myopathy secondary to alcohol?


Answer: Calf muscles

Acute alcoholic myopathy usually occurs during a binge phase with an underlying history of chronic alcoholism. It can be severe enough to cause rhabdomyolysis, and acute kidney injury (AKI). Underlying hypokalemia and hypophosphatemia play the role. An important lesson to remember is that this is a distinct clinical condition and patient may present without any other conditions which are common in chronic alcoholics like delirium tremens (DT). DT can be differentially diagnosed by the fact that it mostly occurs during the abstinence phase, whereas acute alcoholic myopathy is directly proportional to the quantity of alcohol consumed during binge drinking accompanied by starvation. 

Although muscle tenderness is generalized it is more pronounced at the calf muscles. As expected, elevated CPK level with alcohol history is diagnostic but the gold standard is muscle biopsy showing muscle fiber necrosis with subsequent degeneration and regeneration.

#toxicology


References:

1. Haller RG, Knochel JP. Skeletal muscle disease in alcoholism. Med Clin North Am 1984; 68:91.

2. Lafair JS, Myerson RM. Alcoholic myopathy. With special reference to the significance of creatine phosphokinase. Arch Intern Med 1968; 122:417. 

3. Martin F, Ward K, Slavin G, et al. Alcoholic skeletal myopathy, a clinical and pathological study. Q J Med 1985; 55:233.

French to millimeter

Q: Conversion of tube sizes from French (F) gauge system to millimeter (mm) system refers to? (select one)

A) Outer diameter of the tube
B) Inner diameter of the tube


Answer: A


The French gauge system to measure the size of a catheter is first invented by a swiss-born French manufacturer of surgical instruments, named Charrière. Chest tubes are still referred to French sizes. The formula to comprehend the tube size in mm is easy to remember when size is referred to F.

D (mm) = Fr / 3

This Diameter (D) measurement refers to the outer diameter of the tube in conversion.

#procedures

Reference:

Iserson, Kenneth V. (1987). "J.-F.-B. Charrière: The man behind the "French" gauge". Journal of Emergency Medicine. 5 (6): 545–8.

A-line damping

Q: Excessive tubing lengths will cause an arterial line (A-line) to have? (select one) 

 A) Underdamped waveform 
 B) Overdamped waveform 


 Answer: A 

 Tubing connected with stopcocks, excessive tubing lengths, tachycardia, and high output states are the most common causes of underdamped A-line. 

 In contrast, air bubbles in the tubing, kinked tubings, blood clot in the tubing, low flush bag pressure are the most common causes of overdamped A-line. 

 #procedures 
#hemodynamic 


 References: 

Romagnoli S, Ricci Z, Quattrone D, et al. Accuracy of invasive arterial pressure monitoring in cardiovascular patients: an observational study. Crit Care. 2014;18(6):644. Published 2014 Nov 30. doi:10.1186/s13054-014-0644-4

Surgery in CDI

Q: All of the following calls for surgical consultation in Clostridium difficle infection (CDI) except? 

A) Ileus
B) Peritonitis 
C Altered mental status 
D) When WBC count of ≥50,000 cells/mL 
E) Admission to ICU


Answer: D

The objective of the above question is to highlight an extremely important lesson in the surgical management of CDI i.e., "timing is the key and early surgical intervention is preferred in fulminant CDI". There are many indicators which may seem benign but call for a surgical consult in fulminant CDI. It includes hypotension, fever ≥38.5°C, significant abdominal distention or tenderness, altered mental status, WBC count of ≥20,000 cells/mL, lactate levels >2.2 mmol/L, admission to ICU, any sign of organ failures like ARDS or renal failure and no response to antibiotics within 3-5 days.

It may be too late by the time WBC count goes ≥ 50,000 cells/mL.

#infectious-disease
#surgical-critical care 


References:

1. van der Wilden GM, Velmahos GC, Chang Y, et al. Effects of a New Hospital-Wide Surgical Consultation Protocol in Patients with Clostridium difficile Colitis. Surg Infect (Larchmt) 2017; 18:563. 

2. Sailhamer EA, Carson K, Chang Y, et al. Fulminant Clostridium difficile colitis: patterns of care and predictors of mortality. Arch Surg 2009; 144:433. 

3.  Hall JF, Berger D. Outcome of colectomy for Clostridium difficile colitis: a plea for early surgical management. Am J Surg 2008; 196:384. 

4. Ferrada P, Velopulos CG, Sultan S, et al. Timing and type of surgical treatment of Clostridium difficile-associated disease: a practice management guideline from the Eastern Association for the Surgery of Trauma. J Trauma Acute Care Surg 2014; 76:1484.

ACE-I and ARBs and red cells

Q: Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers (ACE-I and ARBs) are prone to cause? (select one) 

 A) Anemia 
B) Erythrocytosis


Answer: A

ACE-I and ARBs suppress the production of erythropoietin. The objective of this question is to bring to attention the benefit of this side effect of  ACE-I and ARBs in at least two situations.

Suppression of erythropoietin by these drugs occur due to an accumulation of N-acetyl-seryl-aspartyl-lysyl-proline which inhibits stem cell multiplication. This makes these drug useful in post-transplant erythrocytosis.

Also, ACE-I and ARBs have shown their utility in polycythemia associated with high altitudes.

#pharmacology
#hematology
#transplantation


References:

1. Yildiz A, Cine N, Akkaya V, et al. Comparison of the effects of enalapril and losartan on posttransplantation erythrocytosis in renal transplant recipients: prospective randomized study. Transplantation 2001; 72:542. 

2. Plata R, Cornejo A, Arratia C, et al. Angiotensin-converting-enzyme inhibition therapy in altitude polycythaemia: a prospective randomised trial. Lancet 2002; 359:663.

pseudo-hyponatremia

Q: What makes hypertriglyceridemia in serum to cause pseudo-hyponatremia?


Answer:  The excess of triglyceride in serum displaces water containing sodium. This falsely reads as hyponatremia on laboratory machine counter.

#electrolytes
#laboratory-medicine


Reference:

Howard JM, Reed J. Pseudohyponatremia in acute hyperlipemic pancreatitis. A potential pitfall in therapy. Arch Surg 1985; 120:1053.

Urine in operative field

Q: 54 year old male is admitted to surgical ICU after a complication in urologic surgery. Patient continues to experience postoperative ileus during the recovery phase. Among all the risk factors, urine in the operating field may contribute to the postoperative development of ileus? (select one)

A) True
B) False


Answer: A

There is a plethora of literature to identify the risk factors for the prolonged postoperative ileus. Few well-known factors include prolonged abdominal or pelvic surgery, open surgery, delayed enteral nutrition or placement of nasogastric tube, development of peritonitis, sepsis or postoperative infectious complications, a requirement of transfusion during surgery, opioid use, peripheral vascular disease, construction of a stoma, lysis of adhesion, disseminated cancer and others. 

In patients who undergo urologic surgery, urine in the operating field may be a contributing factor for a prolonged postoperative ileus.


#surgical-critical-care


Reference:

Mattei A, Birkhaeuser FD, Baermann C, et al. To stent or not to stent perioperatively the ureteroileal anastomosis of ileal orthotopic bladder substitutes and ileal conduits? Results of a prospective randomized trial. J Urol 2008; 179:582.

Magnesium absorption

Q: Absorption of magnesium occurs in the? (select one)

A) proximal intestine 
B) distal intestine


Answer: B

The absorption of magnesium occurs in the distal intestine including the colon. This becomes clinically important as magnesium does not have huge deposition in the body and patients with distal colectomy or with distal small intestinal and colonic disease may develop life-threatening hypomagnesemia resulting in arrhythmias and neurological symptoms.

#electrolytes 
#surgical-critical-care


Reference:

Swaminathan R. Magnesium metabolism and its disorders. Clin Biochem Rev. 2003;24(2):47–66.

Angioedema

Q: Angioedema tends to be? (select one)

A) Asymmetric distribution 
B) Symmetric distribution 


Answer: A

Angioedema with its few unique characteristics can be distinguished at the bedside. It has asymmetric distribution and tendency to not to involve the gravitationally-dependent areas. It mostly involves face, lips, larynx, and bowels.

#allergy-immunology


References: 

Caballero T, Baeza ML, Cabañas R, et al. Consensus statement on the diagnosis, management, and treatment of angioedema mediated by bradykinin. Part I. Classification, epidemiology, pathophysiology, genetics, clinical symptoms, and diagnosis. J Investig Allergol Clin Immunol 2011; 21:333.

Caballero T, Baeza ML, Cabañas R, et al. Consensus statement on the diagnosis, management, and treatment of angioedema mediated by bradykinin. Part II. Treatment, follow-up, and special situations. J Investig Allergol Clin Immunol 2011; 21:422.

TPN and HIT

Q: Total Parenteral Nutrition (TPN) can be a cause of Heparin-induced thrombocytopenia (HIT)? (select one)

A) True
B) False


Answer: A

Although the American Society for Parenteral and Enteral Nutrition (ASPEN) does not recommend it, there is a sizeable practice of supplementing TPN with low dose heparin to decrease the risk of thrombophlebitis and maintain vascular catheter patency. HIT is independent of dosage and even minor exposure can induce it. This is particularly important to address in patients with a high probability of acquiring HIT or when the cause of HIT is ambiguous.

#hematology
#nutrition



References:

1. Lee E, Lee JO, Lim Y, Kim JY, Kim HK, Bang SM. Thrombocytopenia caused by low-dose heparin supplementation of parenteral nutrition solution. Blood Res. 2013;48(2):160–163. 

2. Tighe MJ, Wong C, Martin IG, McMahon MJ. Do heparin, hydrocortisone, and glyceryl trinitrate influence thrombophlebitis during full intravenous nutrition via a peripheral vein? JPEN J Parenter Enteral Nutr. 1995;19:507–509 

3. Joseph I. Boullata & et al, A.S.P.E.N. Clinical Guidelines: Parenteral Nutrition Ordering, Order Review, Compounding, Labeling, and Dispensing . JPEN 2014, Vol 38, Issue 3, pp. 334–377 (table 1)

Phenytoin in theo seizure

Q: Phenytoin may intensify the seizures caused by theophylline? (select one)

A) True
B) False


Answer: A

Phenytoin as well as its pro-drug fosphenytoin may make seizures caused by cocaine and theophylline worse!  Intravenous Benzodiazepines is the preferred drug of treatment. 

#neurology
#pharmacology


References:

1. Wills B, Erickson T. Chemically induced seizures. Clin Lab Med 2006; 26:185. 

2. Paloucek FP, Rodvold KA. Evaluation of theophylline overdoses and toxicities. Ann Emerg Med 1988; 17:135.

splenectomy

Q: In normal physiologic condition, what percentage of platelets are sequestered in the spleen?



Answer: About 33%

Under normal conditions about one-third of circulating platelets are sequestered in the spleen, where they are in equilibrium with circulating platelets. 

Clinical significance: The spleen has an important function related to human circulatory cells. It removes senescent RBCs,  encapsulated organisms, and other particulates from the circulation via monocyte-macrophage system. It is called graveyard of the circulation. Splenectomy due to any reason not only renders the human body to infections but also to venous and arterial thrombosis and pulmonary hypertension.

#surgical-citical-care
#hematology


Reference:

Crary SE, Buchanan GR. Vascular complications after splenectomy for hematologic disorders. Blood 2009; 114:2861.

ILEs

Q: Intravenous lipid emulsions (ILEs) are getting popular as a treatment of choice in the overdose of many drugs. Name few side-effects of its administration?


Answer: ILEs are fastly getting acceptance as one of the treatments in drugs overdose. But it comes with its own perils. Some of the possible side-effects of its administration include:

• acute kidney injury
• cardiac arrest
• ventilation-perfusion mismatch
• acute lung injury
• venous thromboembolism
• hypersensitivity
• fat embolism
• pancreatitis
• extracorporeal circulation machine (ECMO) circuit obstruction
• increased susceptibility to infection
• priapism 

#toxicology


References:

1. Bryan D. Hayes et al. Systematic review of clinical adverse events reported after acute intravenous lipid emulsion administration. Clinical Toxicology Volume 54, 2016 - Issue 5

2. Priapism in patients treated with total parenteral nutrition. Ekström B, Olsson AM. Br J Urol. 1987 Feb; 59(2):170-1.

fondaparinux

Q: Fondaparinux is eliminated via (select one)

A) Kidney
B) liver


Answer: A

Ideally, fondaparinux should be avoided in moderate to severe renal insufficiency, and other agents should be utilized. But if it is absolutely needed, renal adjustment should be done,  particularly in patients with creatinine clearance between 30-50 mL/min.

#pharmacology
#hematology


Reference:

Al-Shaer MH, Ibrahim T. Safety and Efficacy of Fondaparinux in Renal Impairment. J Pharm Technol. 2015;31(4):161–166. 

PHS and PPHTN

Q: How transthoracic echocardiography (TTE) can differentiate between hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN)?



Answer: 

• HPS is a term used when pulmonary hypertension is present with liver disease but the absence of portal HTN.
• PPHTN is a term used exclusively when portal hypertension is present with or without the hepatic disease.

TTE with contrast (bubble study) can distinguish hepatopulmonary syndrome (HPS) and portopulmonary hypertension (PPHTN). Patients with HPS usually have a shunt which can be demonstrated via bubble study. Shunt is usually absent in PPHTN.

Clinical exam can also provide this distinction at bedside as patients with HPS will have platypnea and orthodeoxia.

#pulmonary
#hepatology
#cardiology


References:

1. Rodríguez-Roisin R, Krowka MJ, Hervé P, et al. Pulmonary-Hepatic vascular Disorders (PHD). Eur Respir J 2004; 24:861.

 2. Hadengue A, Benhayoun MK, Lebrec D, Benhamou JP. Pulmonary hypertension complicating portal hypertension: prevalence and relation to splanchnic hemodynamics. Gastroenterology 1991; 100:520.

3. Henkin S, Negrotto S, Pollak PM, Cullen MW, O'Cochlain DF, Wright RS. Platypnea-Orthodeoxia Syndrome: Diagnostic Challenge and the Importance of Heightened Clinical Suspicion. Tex Heart Inst J. 2015;42(5):498–501. Published 2015 Oct 1.

4. Galiè N, Humbert M, Vachiery JL, et al. 2015 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension: The Joint Task Force for the Diagnosis and Treatment of Pulmonary Hypertension of the European Society of Cardiology (ESC) and the European Respiratory Society (ERS): Endorsed by: Association for European Paediatric and Congenital Cardiology (AEPC), International Society for Heart and Lung Transplantation (ISHLT). Eur Respir J 2015; 46:903.

Intubation

Q: What three basic questions a clinician may ask himself before making a decision for intubation?


Answer: Intubation is a clinical decision but it may come with its own price. A clinician should ask himself three questions before making this decision.

• Is airway at risk? 
• Is oxygenation or ventilation failing? 
• Is intubation anticipated in near future (impending)

#procedures

Reference:

Brown 3rd CA, Walls RM. The decision to intubate. In: The Walls Manual of Emergency Airway Management, 5th ed, Lippincott Williams & Wilkins, Philadelphia 2018. p.3.

Pressure ulcer

Q: While turning bedridden patients in ICU to prevent pressure ulcers, at what degree patient should be placed while lying on the side?


Answer: ≤30 degrees angle

Bony prominences are most prone to develop pressure ulcers at predictable points such as heels, sacral and shoulder areas. While turning patients and to lie them on their side, they should be placed at an angle equal or lesser than 30 degrees to avoid pressure over the greater trochanter.

The objective of this question is to emphasize readers to review the article mentioned in the link. (see below)

#icu-care


Reference:

Boyko TV, Longaker MT, Yang GP. Review of the Current Management of Pressure Ulcers. Adv Wound Care (New Rochelle). 2018;7(2):57–67. doi:10.1089/wound.2016.0697

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5792240/

Alcohol related seizure

Q: Seizures due to alcohol withdrawal are more prone to degenerate into status epilepticus? (select one)

A) True
B) False


Answer: B

Seizure due to alcohol withdrawal rarely progresses to status. If an alcoholic patient is found in status epilepticus, it should prompt clinicians to look for other etiologies of seizure. Another reliable clue is that seizure secondary to alcohol withdrawal usually stays unresponsive to phenytoin.

#neurology
#toxicology


References:

1. Kattimani S, Bharadwaj B. Clinical management of alcohol withdrawal: A systematic review. Ind Psychiatry J. 2013;22(2):100–108. 

2. Rathlev NK, D'Onofrio G, Fish SS, et al. The lack of efficacy of phenytoin in the prevention of recurrent alcohol-related seizures. Ann Emerg Med 1994; 23:513.

Laryngeal injury during intubation

Q: Risk factors for laryngeal injury during intubation include all of the following except? 

A) Traumatic intubation 
B) Using a myorelaxant 
C) Large Endo-Tracheal-Tube (ETT)
D) Aspiration 
E) Presence of a nasogastric tube


Answer: B

There are several risk factors for laryngeal injury during and after the procedure is done. Use of neuro-muscular blockade (NMB) during intubation decreases the risk of laryngeal injury. Other risk factors include female gender, older age, traumatic intubation, wider ETT, aspiration during or afterward the procedure, unplanned extubation, and presence of a nasogastric tube. Also, underlying co-morbidities like diabetes, hypertension, decreased cardiac ejection fraction, renal insufficiency, and malnutrition are risk factors. 

Important to note that obesity is not included in this list as higher BMI may be associated with difficult intubation but not the laryngeal injury unless an operation turned it into a traumatic work.

#procedure


References:

1. Tadié JM, Behm E, Lecuyer L, et al. Post-intubation laryngeal injuries and extubation failure: a fiberoptic endoscopic study. Intensive Care Med 2010; 36:991. 

2. Friedman M, Baim H, Shelton V, et al. Laryngeal injuries secondary to nasogastric tubes. Ann Otol Rhinol Laryngol 1981; 90:469. 

3. Kikura M, Suzuki K, Itagaki T, et al. Age and comorbidity as risk factors for vocal cord paralysis associated with tracheal intubation. Br J Anaesth 2007; 98:524. 

4.  Dargin JM, Emlet LL, Guyette FX. The effect of body mass index on intubation success rates and complications during emergency airway management. Intern Emerg Med 2013; 8:75.

Löfgren syndrome

Q: 27 year old male is admitted to ICU with fever, dehydration, hypotension, bilateral ankle arthritis. CXR showed hilar adenopathy. The resident on call put Löfgren syndrome in differential diagnosis despite no presence of erythema nodosum. He argues that male patients may not have erythema nodosum in Löfgren syndrome? (select one)  

A) True
B) False


Answer: A

Löfgren syndrome (acute sarcoidosis) is a cluster of symptoms in acute sarcoidosis, comprising of erythema nodosum (EN), hilar adenopathy, migratory polyarthralgia, and fever. All classic symptoms are usually present in women, and clinical features can be so overwhelming that diagnosis may not even require biopsy. Male patients with Löfgren syndrome usually present with signs of bilateral ankle arthritis, but without EN.

#rheumatology


References:

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

2. O'Regan A, Berman JS. Sarcoidosis. Ann Intern Med 2012; 156:ITC5.

GERD

Case: 34 year old healthy male is admitted to ICU with confusion and trembling. CT scan done in ED is negative. Wife informed that the only positive past medical history (PMH) is of Gastro-Esophageal-Reflux-Disease (GERD) which was not getting improved with Proton-Pump-Inhibitors (PPIs) and recently his physician prescribed him a new medicine as a four weeks trial. What medicine is highly suspected?


Answer: Baclofen.

Baclofen is frequently used as a second line treatment particularly in non-acid reflux GERD as a trial. Baclofen reduces the incidence of transient lower esophageal sphincter relaxation. Baclofen crosses the blood-brain barrier, and may result in symptoms like somnolence, confusion, drowsiness, and trembling. This side effect is a major barrier to the use of baclofen in the treatment of GERD. It should be started at a lower dose and titrated up while watching the side effects. A trial of 4 to 8 weeks seems appropriate.

#pharmacology
#gastroenterology
#neurology


References:

1. Shujie Li, Shengying Shi, Feng Chen, and Jingming Lin. Review Article The Effects of Baclofen for the Treatment of Gastroesophageal Reflux Disease: A Meta-Analysis of Randomized Controlled Trials Gastroenterology Research and Practice Volume 2014, Article ID 307805, 8 pages http://dx.doi.org/10.1155/2014/307805

2. Vela MF, Tutuian R, Katz PO, Castell DO. Baclofen decreases acid and non-acid post-prandial gastro-oesophageal reflux measured by combined multichannel intraluminal impedance and pH. Aliment Pharmacol Ther 2003; 17:243. 

3. Koek GH, Sifrim D, Lerut T, et al. Effect of the GABA(B) agonist baclofen in patients with symptoms and duodeno-gastro-oesophageal reflux refractory to proton pump inhibitors. Gut 2003; 52:1397.

diarrhea in amebiasis

Q: Bloody diarrhea in amebiasis is accompanied? (select one) 

 A) with fecal leukocytes 
 B) without fecal leukocytes


Answer: B

Few of the hallmarks of intestinal amebiasis are bloody diarrhea, usually present for an extended period of time and absence of fecal leukocytes. Intestinal amebiasis destroys leukocytes. These features in high-risk populations are highly suggestive of the said disease. High-risk populations for intestinal amebiasis are endemic geographic areas like Sout-East Asia, Africa, Mexico, and parts of Central and South America, institutionalized persons and men who have sex with men.

#infectious-diseases
#gastroenterology


References:

1. Tanyuksel M, Petri WA Jr. Laboratory diagnosis of amebiasis. Clin Microbiol Rev. 2003;16(4):713–729.

2. Hung CC, Ji DD, Sun HY, et al. Increased risk for Entamoeba histolytica infection and invasive amebiasis in HIV seropositive men who have sex with men in Taiwan. PLoS Negl Trop Dis. 2008;2(2):e175.

3. Choudhuri G, Rangan M. Amebic infection in humans. Indian J Gastroenterol. 2012 Jul;31(4):153–62.

Antibiotic stewardship

Q: All of the following are considered valid outcome measures of Antimicrobial stewardship except?

A) Rate of double coverage at the initiation of therapy 
B) Hospital and ICU length of stay (LOS)
C) Readmission rates
D) C. difficile infection rates
E) Emergence of antimicrobial resistance over time


Answer: A

In the United States, the Joint Commission required all hospitals to implement antimicrobial stewardship programs. There are two major categories for evaluation of the stewardship program, each consist of five metrics

1) Process measures
2) Outcome measures

Process measures 

• Unnecessary days of therapy 
• Duration of therapy 
• Proportion of patients compliant with facility-based guideline
• Proportion of patients with revision of antibiotics based on microbiology data 
• Proportion of patients converted to oral therapy 

Outcome measures

• Hospital LOS
• 30-day mortality 
• Unplanned hospital readmission within 30 days 
• Proportion of patients with hospital-acquired C. difficile or other adverse event(s) related to antibiotics
• Proportion of patients with clinical failure 

#infectious-diseases


Reference:

Barlam TF, Cosgrove SE, Abbo LM, et al. Implementing an antibiotic stewardship program: Guidelines by the Infectious Diseases Society of America and the Society for Healthcare Epidemiology of America. Clin Infect Dis 2016; 62(10):e51-77

Anaphylaxis

Q: All of the following drugs can compound anaphylaxis reaction except? 

A) Beta-blockers (BB)
B) Angiotensin-converting enzyme inhibitors (ACE-I)
C) Acetaminophen
D) Tricyclic antidepressants (TCA)
E) Cocaine


Answer: C

Anaphylaxis is relatively hard to treat in patients who are on beta-adrenergic blockers as they cause unopposed alpha-adrenergic effects, hypertension, and reduced bronchodilator response to the beta-adrenergic effects when epinephrine is administrated (choice A).

ACE-I can potentially interfere with endogenous compensatory responses (choice B).

TCA can potentially increase in adverse effects of epinephrine because of prevention of epinephrine uptake at adrenergic receptors (choice D).

Cocaine potentiates the epinephrine's effects, especially cardiovascular effects, by preventing its reuptake into adrenergic neurons (choice E). 

Acetaminophen has no direct effect on anaphylaxis.


#Allergy
#pharmacology


Reference:

Simons FER. Anaphylaxis, killer allergy: Long-term management in the community. J Allergy Clin Immunol 2006; 117:367. 

Cyanosis and Pulseox

Q: Frank cyanosis of a patient generally corresponds to what level of arterial oxygen saturation (SaO2)?

Answer:  67 percent

The oxygen saturation level at which patient becomes apparently cyanotic depends on many factors like tissue perfusion, skin color, or hemoglobin concentration, but at least one study showed that apparent cyanosis of patient corresponds to massive hypoxemia of 67 % 1.

#oxygenation




Reference:

1. Grace RF. Pulse oximetry. Gold standard or false sense of security? Med J Aust 1994; 160:638.

2. Hanning CD, Alexander-Williams JM. Pulse oximetry: a practical review. BMJ 1995; 311:367.

delirium

Q: In patients who develop delirium in ICU, their delusions and hallucinations should be challenged to orient them to reality? (select one)

A) True
B) False


Answer: B

We have learned that non-pharmacologic interventions works better in delirium particularly in ICU. It includes noise control, proper lightening, early mobilization, providing outside view (window), eye contact, availability of loved ones in the room, minimizing drug toxicities and many others. Although frequent reassurances is required but challenging their delusions and hallucinations may worsen delirium. They should neither be endorsed nor challenged.

#neurology
#psychiatry 


Further readings:

1. Fong TG, Tulebaev SR, Inouye SK. Delirium in elderly adults: diagnosis, prevention and treatment. Nat Rev Neurol. 2009;5(4):210–220. doi:10.1038/nrneurol.2009.24

2. O'Mahony R, Murthy L, Akunne A, et al. Synopsis of the National Institute for Health and Clinical Excellence guideline for prevention of delirium. Ann Intern Med 2011; 154:746. 

3. Hshieh TT, Yue J, Oh E, et al. Effectiveness of multicomponent nonpharmacological delirium interventions: a meta-analysis. JAMA Intern Med 2015; 175:512.

diuretic resistant cirrhosis

Q:55 year old male with history of cirrhosis is admitted to ICU with hypotension, volume overload, and massive ascites. Patient is reported by his family to adherent to his medicines but lately, a new medicine was prescribed by his primary care physician. Addition of which of the following drugs is known to cause decrease diuretic responsiveness? 

A) Nonsteroidal antiinflammatory drug (NSAID) 
B) Midodrine 
C) Colloid
D) Vaptans 
E) Clonidine


Answer: A

NSAIDs are the inhibitors of renal prostaglandins, which leads to renal vasoconstriction, causing lesser response to diuretics.

Midodrine as an oral vasopressor increases blood pressure, and can be very useful in cirrhosis to improve renal perfusion.

Clonidine is helpful in diuretic resistant ascites. It is an alpha-2-adrenergic receptor agonist and suppresses the renin-aldosterone system, which are known to be activated in patients with diuretic-resistant ascites.

Colloid are indicated in cirrhosis.

Vaptans have been tried in cirrhosis but one of the vaptan (tolvaptan), is associated with liver injury, but not known to cause direct diuretic resistant cirrhosis.


#hepatology
#pharmacology



 References:

1. Arroyo V, Ginés P, Rimola A, Gaya J. Renal function abnormalities, prostaglandins, and effects of nonsteroidal anti-inflammatory drugs in cirrhosis with ascites. An overview with emphasis on pathogenesis. Am J Med 1986; 81:104.

2. Runyon BA. Refractory ascites. Semin Liver Dis 1993; 13:343.

3. Singh V, Dhungana SP, Singh B, et al. Midodrine in patients with cirrhosis and refractory or recurrent ascites: a randomized pilot study. J Hepatol 2012; 56:348.

4. Boyer TD. Tolvaptan and hyponatremia in a patient with cirrhosis. Hepatology 2010; 51:699.

5. Singh V, Singh A, Singh B, et al. Midodrine and clonidine in patients with cirrhosis and refractory or recurrent ascites: a randomized pilot study. Am J Gastroenterol 2013; 108:560.

REPE

Q; Development of cough during thoracentesis indicates the sign of reexpansion pulmonary edema (REPE) and procedure should be stopped? (select one)

A) True
B) False


Answer: B

Indeed, the development of cough during thoracentesis indicates the reexpansion of lung but it has no correlation with reexpansion pulmonary edema (REPE). 

Interestingly, a younger person between the age of 20 and 40 years is at a higher risk of REPE. Other risk factors include prolonged presence of pleural effusion, the application of high negative pressures during the procedure i.e.> - 20 cm H2O, and a large volumes thoracentesis i.e. > 1.5 L.

Procedure should only be stopped if cough becomes unbearable or patient shows signs of pulmonary edema such as shortness of breath or pink frothy sputum.

#pulmonary
#procedures


References:

1. Feller-Kopman D, Berkowitz D, Boiselle P, et al. Large-volume thoracentesis and the risk of reexpansion pulmonary edema. Ann Thorac Surg 2007;84:1656–61  

2. Sherman SC. Reexpansion pulmonary edema: a case report and review of the current literature. J Emerg Med 2003;24:23–7 

3. Matsuura Y, Nomimura T, Murakami H, et al. Clinical analysis of reexpansion pulmonary edema. Chest 1991;100:1562–6 

4. Feller-Kopman D, Parker MJ, Schwartzstein RM. Assessment of pleural pressure in the evaluation of pleural effusions. Chest 2009;135:201–9

phenobarb in theo toxicity

Q: What added advantage phenobarbital has in the treatment of theophylline-induced seizures?

Answer: Barbiturates is the drug of choice in theophylline toxicity. But in case, phenobarbital is used to treat theophylline-induced seizure - it has the added advantage of enhancing the hepatic metabolism of theophylline.

#neurology
#pharmacology 


Reference:

Landay RA, Gonzalez MA, Taylor JC. Effect of phenobarbital on theophylline disposition. J Allergy Clin Immunol. 1978 Jul;62(1):27-9.