alkanization of urine and barbiturates

 Q: Which of the following barbiturate requires alkalinization of urine?

A) short-acting

B) long-acting

Answer: B

Long-acting barbiturates like Phenobarbital requires alkalinization of urine. Short-acting barbiturates metabolized hepatically. When urine is alkalinized a lipid-soluble intact acid or base in the tubular lumen converts into the charged salt. The charged salt becomes lipid-insoluble and cannot move back across the epithelium, and excreted in the urine.

Few other drugs that respond well to alkalinization of urine include chlorpropamide,  salicylates, methotrexate, and sulfonamides. 

#toxicology

References:

1. Henry JA. Specific problems of drug intoxication. Br J Anaesth 1986; 58:223. 

2. Proudfoot AT, Krenzelok EP, Vale JA. Position Paper on urine alkalinization. J Toxicol Clin Toxicol 2004; 42:1.

steroids in migraine

 Q: 43 years old female is admitted to ICU with a severe headache. Diagnostic workup was essentially negative and the patient was diagnosed as status migrainosus in view of her previous history. Intravenous dexamethasone may be useful in resolving the acute attack? 

 A) True 

 B) False 

 Answer: B 

Status migrainosus is defined as a severe intractable migraine attack lasting for more than 72 hours. Standard treatment includes intravenous fluids (IVF), IV ketorolac, a dopamine receptor blocker. valproate, NSAID, and dihydroergotamine. Dexamethasone has no role in the relief of an acute attack or status migrainosus. But it is very effective in preventing relapse from 24 to 72 hours after treatment.

#neurology

References:

1. Colman I, Friedman BW, Brown MD, et al. Parenteral dexamethasone for acute severe migraine headache: meta-analysis of randomised controlled trials for preventing recurrence. BMJ 2008; 336:1359. 2. 

2. Singh A, Alter HJ, Zaia B. Does the addition of dexamethasone to standard therapy for acute migraine headache decrease the incidence of recurrent headache for patients treated in the emergency department? A meta-analysis and systematic review of the literature. Acad Emerg Med 2008; 15:1223. 

3. Rozen TD. Emergency Department and Inpatient Management of Status Migrainosus and Intractable Headache. Continuum (Minneap Minn) 2015; 21:1004. 

4. Iljazi A, Chua A, Rich-Fiondella R, et al. Unrecognized challenges of treating status migrainosus: An observational study. Cephalalgia 2020; 40:818.

Procal and advance COVID

 Q:  Procalcitonin is a reliable indicator in advanced COVID-19 patients to predict superimposed bacterial infection?

A) True

B) False

Answer: B

Literature for COVID-19 is constantly evolving. So far there is no indication that secondary bacterial infection is a norm in advanced COVID-19. In suspected cases, standard management with blood and sputum cultures and initiation of antibiotics is appropriate. COVID-19 cohort of patients from Wuhan, China showed that relying solely on procalcitonin is not appropriate as elevated procalcitonin levels have been reported in advanced COVID-19 patients without any specific indication of secondary bacterial infection.

#infectious-diseases 

#COVID-19

References:

1. Wang D, Hu B, Hu C, et al. Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus-Infected Pneumonia in Wuhan, China. JAMA 2020; 323:1061. 

 2. Guan WJ, Ni ZY, Hu Y, et al. Clinical Characteristics of Coronavirus Disease 2019 in China. N Engl J Med 2020; 382:1708. 

 3. Wu C, Chen X, Cai Y, et al. Risk Factors Associated With Acute Respiratory Distress Syndrome and Death in Patients With Coronavirus Disease 2019 Pneumonia in Wuhan, China. JAMA Intern Med 2020; 180:934. 

4. Zhou F, Yu T, Du R, et al. Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study. Lancet 2020; 395:1054.

Pressor and SC route of meds

 Q: Patients on high doses of vasopressor in ICU may require higher doses of deep venous thrombosis (DVT) prophylaxes than usual?

A) True

B) False

Answer: A

Patients on high dose of vasopressors develop cutaneous vasoconstriction. This leads to decreased bioavailability of medications which are usually delivered subcutaneously (SQ) such as insulin and heparins. 

At least one study look into this phenomenon comparing three commonly used pressors in ICU i.e., dopamine (@ >10 mcg/kg/min), norepinephrine (@ >0.25 mcg/kg/min), and phenylephrine (@>2 mcg/kg/min). Patients were found to have a decreased factor Xa activity with the comparable group. The study had a very small sample size of only 15 patients, and requires a larger trial in association with various variabilities/confounders. Said that, theoretically it points towards at least one of the causes of higher rates of poor blood-glucose control and increase DVTs in ICU despite appropriate measures.

#pharmacology

Reference:

Dörffler-Melly J, de Jonge E, Pont AC, et al. Bioavailability of subcutaneous low-molecular-weight heparin to patients on vasopressors. Lancet 2002; 359:849.

on cholera

 Q; 21 years old male who just returned from Indian subcontinent is admitted to ICU with severe dehydration and hypotension. Patient is diagnosed with cholera. One of the main pathology in cholera is that the intestines cannot absorb water and electrolytes, and results in large secreting diarrhea?

A) True

B) False

Answer: B

Despite cholera pathogen present, the intestines could still absorb water and electrolytes. This holds true despite large secreting diarrhea. This seems trivial but this is the basis of management in cholera with fluid resuscitation, hydration and repletion of electrolytes.

#infectious-diseases

References:

Muanprasat C, Chatsudthipong V. Cholera: pathophysiology and emerging therapeutic targets. Future Med Chem. 2013 May;5(7):781-98. doi: 10.4155/fmc.13.42. PMID: 23651092.

On Fondaparinux

Q: Fondaparinux is a unique agent used in Heparin Induced Thrombocytopenia (HIT) which can be given subcutaneously. Despite its easy method of administration what three points should be of concern when prescribing Fondaparinux for HIT? 

 Answer: Fondaparinux is a chemically synthesized version of the active pentasaccharide subunit of heparin, but it does not interact with platelet factor 4, and can be used in the management of HIT. Also, there is no need to monitor coagulation parameters. If needed, the drug level can be measured though. It can be a good agent for use on an outpatient basis. It can be used on a long term basis like in a pregnant patient. Despite its ease of use and other advantages, it is not considered the first line of treatment in HIT. The three major drawbacks with its use are 

•  long half-life of 17 hours 
•  renal excretion, and 
•  no antidote

#hematology

References:

1. Linkins LA, Dans AL, Moores LK, et al. Treatment and prevention of heparin-induced thrombocytopenia: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012; 141:e495S. 

2. Warkentin TE, Pai M, Sheppard JI, et al. Fondaparinux treatment of acute heparin-induced thrombocytopenia confirmed by the serotonin-release assay: a 30-month, 16-patient case series. J Thromb Haemost 2011; 9:2389. 

3. Goldfarb MJ, Blostein MD. Fondaparinux in acute heparin-induced thrombocytopenia: a case series. J Thromb Haemost 2011; 9:2501. 

4. Mazzolai L, Hohlfeld P, Spertini F, et al. Fondaparinux is a safe alternative in case of heparin intolerance during pregnancy. Blood 2006; 108:1569. 

5. Gerhardt A, Zotz RB, Stockschlaeder M, Scharf RE. Fondaparinux is an effective alternative anticoagulant in pregnant women with high risk of venous thromboembolism and intolerance to low-molecular-weight heparins and heparinoids. Thromb Haemost 2007; 97:496.

CDI - Anion-binding resins

Q: Anion-binding resins are considered an effective alternative treatment in frequently relapsing Clostridioides/Clostridium difficile infection (CDI)? 

A) True

B) False

Answer: B

Tolevamer is a C. difficile specific toxin–binding resin. Despite high expectations from early trial (2006) they failed to show any advantage over traditional vancomycin and metronidazole therapy in subsequent large trial (2014). On the same principle, anion-binding resins i.e., colestipol and cholestyramine were tried but found to have no superior value. They can be used an adjuvant treatments but not as an alternative treatments.

#ID

#pharmacology

References:

1. Johnson S, Louie TJ, Gerding DN, et al. Vancomycin, metronidazole, or tolevamer for Clostridium difficile infection: results from two multinational, randomized, controlled trials. Clin Infect Dis 2014; 59:345.

2. Louie TJ, Peppe J, Watt CK, et al. Tolevamer, a novel nonantibiotic polymer, compared with vancomycin in the treatment of mild to moderately severe Clostridium difficile-associated diarrhea. Clin Infect Dis 2006; 43:411. 

3. Kreutzer EW, Milligan FD. Treatment of antibiotic-associated pseudomembranous colitis with cholestyramine resin. Johns Hopkins Med J 1978; 143:67.

difference in diarrhea of small and large infections

 Q: When only the small bowel is involved in enteritis, fever is rarely present? (select one)

A) True

B) False

Answer: A

The few important clues to distinguish between diarrhea due to small and large bowel infections is the presence or absence of fever, occult blood, or inflammatory cells. 

When only the small bowel enteritis is present fever, occult blood, or inflammatory cells are usually absent. It is mostly characterized by a large volume watery diarrhea, cramping, and bloating. The common causes are viruses. 

In the large bowel infectious colitis, fever, bloody or mucoid stools are universally present, and RBCs and inflammatory cells are routinely seen on stool smear. The symptom is usually frequent, small-volume, painful diarrhea. The common causes are bacteria.

#infectious-diseases 

References:

1. Wanke C, Guerrant R. Infectious gastroenteritis. In: Medicine for the Practicing Physician, 4th Ed, Hurst J (Ed), Appleton & Lange, Stamford, CT 1996. p.340. 

2. Wanke CA. Small intestinal infections. Curr Opin Gastroenterol 1994; 10:59. 

3. Guerrant RL, Van Gilder T, Steiner TS, et al. Practice guidelines for the management of infectious diarrhea. Clin Infect Dis 2001; 32:331.

serotonin syndrome

 Q: In serotonin syndrome, bowel sounds tend to be? (select one)

A) hypoactive

B) hyperactive

Answer: B

The objective of this question is to emphasize the importance of physical exam in serotonin toxicity which may be the only clue besides history. In contrast to opioid toxicity, serotonin syndrome tends to have a hyperactive state of body functions including increase bowel sounds on abdominal auscultation. Other important signs include:

• tachycardia 
• dramatic swings in blood pressure
• dramatic swings in pulse 
• hyperthermia
• agitation 
• ocular clonus
• dilated pupils 
• tremor 
• akathisia 
• deep tendon hyperreflexia 
• muscle clonus and rigidity 
• positive Babinski signs 
• dry mucus 
• flushed skin 
• diaphoresis 

#toxicology

References:

1. Boyer EW, Shannon M. The serotonin syndrome. N Engl J Med 2005; 352:1112. 

2. Birmes P, Coppin D, Schmitt L, Lauque D. Serotonin syndrome: a brief review. CMAJ 2003; 168:1439. 

3. Mason PJ, Morris VA, Balcezak TJ. Serotonin syndrome. Presentation of 2 cases and review of the literature. Medicine (Baltimore) 2000; 79:201.

ASA overdose and electrolytes

 Q: Which of the following electrolyte abnormality should be treated aggressively in salicylate overdose?

A) Hyponatremia

B) Hypernatremia

C) Hypokalemia

D) Hyperkalemia

E) Hypocalcemia

Answer: C

Hypokalemia should be treated aggressively in salicylate poisoning. The presence of hypokalemia enhances the activity of the K+/H+ exchange pump in the distal tubule. This increases the absorption of potassium with excretion of H+ ion in the urine. This compromises any effort by a clinician to alkalinize the urine which is the mainstay of treatment in salicylate poisoning. In the presence of hypokalemia, treatment becomes ineffective.

#toxicology

Reference:

American College of Medical Toxicology. Guidance document: management priorities in salicylate toxicity. J Med Toxicol. 2015;11(1):149-152. doi:10.1007/s13181-013-0362-3

Flumazanil

 Q: Can flumazenil be used as a continous intravenous (IV) infusion in severe benzodiazepines (BZD) overdose?

A) Yes

B) No

Answer: A

Although not a very desirable act but in extreme situations where the goal is to prevent intubation and a clinician is experienced - a continuous flumazenil infusion can be an option in severe BZD overdose. The rate is usually 0.25 to 1 mg per hour. This is due to the fact that the effect of flumazenil is shorter than half-lives of most BZDs. The effect of Flumazenil can last anywhere from 0.7 to 1.3 hours. A continuous infusion can be a salvage when a known BZD has a very long half-life, the quantity of overdose is high or a patient has an underlying liver insufficiency.

#toxicology

References:

1. Maxa JL, Ogu CC, Adeeko MA, Swaner TG. Continuous-infusion flumazenil in the management of chlordiazepoxide toxicity. Pharmacotherapy 2003; 23:1513. 

2. Höjer J, Baehrendtz S, Magnusson A, Gustafsson LL. A placebo-controlled trial of flumazenil given by continuous infusion in severe benzodiazepine overdosage. Acta Anaesthesiol Scand 1991; 35:584.

esophageal pressure while on ventilator

 Q: Esophageal pressure (PES) is an estimate of? (select one) 

A) Transpulmonary pressure 

B) Airway pressure 

 C) Pleural pressure 

D) All of the above 

 Answer: C

Esophageal pressure (PES) is a good surrogate estimate of pleural pressure. It is measured via an esophageal balloon catheter. It provides an essential value to compute in the calculation of transpulmonary pressure formula: 

Transpulmonary pressure = airway pressure - pleural pressure 

Applying Positive-End-Expiratory-Pressure (PEEP) in adjustment with pleural pressure to 

• keep an end-expiratory transpulmonary pressure between 0 to 10 cm H2O prevents cyclic alveolar collapse, and 
•  maintaining an end-inspiratory transpulmonary pressure ≤ 25 cm H2O reduces alveolar overdistension

Despite its efficacy has been demonstrated in few trials, clinically it is found to be cumbersome at the bedside to use routinely due to a need for extra necessary equipment as well as trained staff.

#ventilators

References:

1. Talmor D, Sarge T, Malhotra A, et al. Mechanical ventilation guided by esophageal pressure in acute lung injury. N Engl J Med 2008; 359:2095. 

2. Beitler JR, Sarge T, Banner-Goodspeed VM, et al. Effect of Titrating Positive End-Expiratory Pressure (PEEP) With an Esophageal Pressure-Guided Strategy vs an Empirical High PEEP-Fio2 Strategy on Death and Days Free From Mechanical Ventilation Among Patients With Acute Respiratory Distress Syndrome: A Randomized Clinical Trial. JAMA 2019; 321:846. 

3. Bernard GR. PEEP guided by esophageal pressure--any added value? N Engl J Med 2008; 359:2166.

cholesterol emboli in IABP

 Q: 58 years old male is in ICU with cardiogenic shock. Patient continues to require Intra Aortic Balloon Pump (IABP) for hemodynamic support. Which features to watch for cholesterol emboli?

Answer:

One of the undesirable consequences of IABP is cholesterol embolization. Some of the cardinal features of this complication are:

• thrombocytopenia
• livedo reticularis
• eosinophilia, and
• eosinophils in the urine sediment (signifies renal atheroemboli)

One of the most important clinical lessons in this situation is NOT to use chronic anticoagulation unless absolutely needed. This may lead to promoting further embolization. The best intervention is to remove the IABP.

#procedure

References:

1.Alderman JD, Gabliani GI, McCabe CH, et al. Incidence and management of limb ischemia with percutaneous wire-guided intraaortic balloon catheters. J Am Coll Cardiol 1987; 9:524. 

2. Hyman BT, Landas SK, Ashman RF, et al. Warfarin-related purple toes syndrome and cholesterol microembolization. Am J Med 1987; 82:1233.

Distinction between purulent pericarditis and infectious pericarditis

 Q: Purulent pericarditis is the severe form of infectious pericarditis?

A) True

B) False

Answer: B 

The objective of the question is to teach the pearl that not necessarily all purulent pericarditis are infectious. The distinction between purulent pericarditis and infectious pericarditis is important. Clinically they require different management. Purulent pericarditis by definition is a localized infection of the pericardial space characterized by gross pus in the pericardium or microscopic purulence with > 20 leukocytes per oil immersion field. It should be noted that not all infections lead to purulent effusions such as Mycoplasma hominis or viral infections. On contrast, many non-infectious inflammatory diseases may create a pericardial exudate with >50,000 white cells/microL.

#cardiology

#infectious-diseases

References:

1. S. V. Parikh, N. Memon, M. Echols, J. Shah, D. K. McGuire, and E. C. Keeley, “Purulent pericarditis: report of 2 cases and review of the literature,” Medicine, vol. 88, no. 1, pp. 52–65, 2009. 

2. Pankuweit S, Ristić AD, Seferović PM, Maisch B. Bacterial pericarditis: diagnosis and management. Am J Cardiovasc Drugs. 2005;5(2):103-12. doi: 10.2165/00129784-200505020-00004. PMID: 15725041.

Propofol dose - COVID

 Q: What precaution a clinician should take while using propofol in sedated intubated COVID-19 patients?

Answer: As standard propofol has been supplied in a bottle with a dose of 10 mg/ml. COVID-19 caused an exponentially high demand for propofol across the USA due to an unexpectedly high number of intubated patients. FDA has allowed a temporary relaxation in this dose preparation up to 20 mg/mL (2 percent dose). Although pharmacists in ICU across the USA are very involved in the management of COVID patients, clinicians are equally liable to check the infusing drips at the bedside. An unintentional overdose of propofol can be fatal in these sets of already fragile patients. Automated alerts on EMR should be updated/applied as a safety measure.

#pharmacology

Reference:

US Food and Drug Administration. Fact sheet for healthcare providers: Emergency use authorization (EUA) of Fresenius Propoven (propofol) 2% emulsion. https://www.fda.gov/media/137889/download (Accessed on November 5, 2020).

refractory NV and atypical antipsychotics

 Q: What is the utility of an atypical antipsychotic agent in refractory nausea and vomiting due to opioids in patients with advanced cancer?

Answer: End of life care is an integral part of ICU work. In patients who are going through compassionate care may develop side effects from opioid administration. The most common is refractory nausea and vomiting. In such cases, one option is to use atypical antipsychotic agents. The dose of risperidone is 1 mg daily and is very useful in refractory nausea and vomiting. Olanzapine can also be used. These agents are also found to be helpful in chemotherapy-induced nausea and vomiting.

#palliative-care

#gastroenterology

References:

1. Okamoto Y, Tsuneto S, Matsuda Y, et al. A retrospective chart review of the antiemetic effectiveness of risperidone in refractory opioid-induced nausea and vomiting in advanced cancer patients. J Pain Symptom Manage 2007; 34:217. 

2. 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.

Tranexamic acid in UGIB

 Q: Tranexamic acid is found to be a good adjuvant treatment in patients with resistant severe upper gastrointestinal bleed (UGIB)? (select one) 

 A) True 

B) False 

 

Answer: B 

Although it makes sense to add antifibrinolytic therapy in a desperate situation where (UGIB) is hard to control, studies have shown that on the contrary Tranexamic acid can be harmful and provides no benefit. It increases the risk of deep vein thrombosis (DVT), pulmonary embolism(PE), and seizures. 

So far, tranexamic acid has no role in the management of UGIB.

#gastroenterology

#hematology

Reference

1. Bennett C, Klingenberg SL, Langholz E, Gluud LL. Tranexamic acid for upper gastrointestinal bleeding. Cochrane Database Syst Rev 2014; :CD006640. 

2. HALT-IT Trial Collaborators. Effects of a high-dose 24-h infusion of tranexamic acid on death and thromboembolic events in patients with acute gastrointestinal bleeding (HALT-IT): an international randomised, double-blind, placebo-controlled trial. Lancet 2020; 395:1927.

old vs new blood

 Q: Freshly acquired pRBC has better outcomes in critically ill patients than stored pRBC?

A) true

B) false

Answer: B

Multiple trials have now established that there is no difference in mortality, morbidity, length of stay (LOS) and coagulation or immune parameters in patients who received either fresh blood or old blood. Few major trials in this regard are 

1. INFORM trial (Informing Fresh versus Old Red Cell Management), 
2. ABLE trial (Age of Blood Evaluation), 
3. TRANSFUSE trial (Standard Issue Transfusion versus Fresher Red-Cell Use in Intensive Care), and 
4.  RECESS trial (Red Cell Storage Duration Study)

#hematology

References:

1. Heddle NM, Cook RJ, Arnold DM, et al. Effect of short-term vs. long-term blood storage on mortality after transfusion. N Engl J Med. 2016;375:1937–45. 

2. Lacroix J, Hébert PC, Fergusson DA, et al. Age of transfused blood in critically ill adults. N Engl J Med 2015; 372:1410. 

3. Steiner ME, Ness PM, Assmann SF, et al. Effects of red-cell storage duration on patients undergoing cardiac surgery. N Engl J Med 2015; 372:1419. 

4. Spinella PC, Sniecinski RM, Trachtenberg F, et al. Effects of blood storage age on immune, coagulation, and nitric oxide parameters in transfused patients undergoing cardiac surgery. Transfusion 2019; 59:1209. 

5. Alexander PE, Barty R, Fei Y, et al. Transfusion of fresher vs older red blood cells in hospitalized patients: a systematic review and meta-analysis. Blood 2016; 127:400. 

6. Irving A, Higgins A, Ady B, Bellomo R, Cooper DJ, French C, Gantner D, Harris A, Irving DO, Murray L, Nichol A, Petrie D, McQuilten ZK; Standard Issue Transfusion versus Fresher Red-Cell Use in Intensive Care (TRANSFUSE) Investigators and Australian and New Zealand Intensive Care Society Clinical Trials Group. Fresh Red Cells for Transfusion in Critically Ill Adults: An Economic Evaluation of the Standard Issue Transfusion Versus Fresher Red-Cell Use in Intensive Care (TRANSFUSE) Clinical Trial. Crit Care Med. 2019 Jul;47(7):e572-e579. doi: 10.1097/CCM.0000000000003781. PMID: 31008734.

UA- reading

 Q: Is the specific gravity of urine a good estimate of urine osmolality? 

Answer: Only if it is low

The urine osmolality is determined by the number of particles in the urine like urea, sodium, and potassium. On the other hand, the specific gravity is determined by both the number and size of the particles in the urine. e.g., if there is glycosuria or if there is a radiocontrast media in the urine, the specific gravity can be high but a urine osmolality will still be telling a diluted story. 

Said that, if the urine specific gravity is reported low, it is 100% an indicative of diluted urine.

#basics

#nephrology

Reference:

Imran S, Eva G, Christopher S, Flynn E, Henner D. Is specific gravity a good estimate of urine osmolality? J Clin Lab Anal. 2010;24(6):426-30. doi: 10.1002/jcla.20424. PMID: 21089176; PMCID: PMC6647580.

Coumadin loading dose

 Q: In an averaged frame patients, the initial recommended warfarin/coumarin dose is?

A) 5mg

B) 10 mg

Answer: A

The concept of "loading" dose of coumarin is no more acceptable unless a patient is known to require a higher dose of warfarin in the past. There are two rationales behind it. 

First, the "front-loading" of warfarin with 10 mg has shown to fail either rapid therapeutic anticoagulation or any therapeutic benefit, rather it can increase the risk of bleeding. 

Second, a higher loading dose (10 mg for the first few days) may cause a sudden fall in factors protein S and protein C, leading to a transient procoagulant state.

#hematology

References:

1. Crowther MA, Ginsberg JB, Kearon C, et al. A randomized trial comparing 5-mg and 10-mg warfarin loading doses. Arch Intern Med 1999; 159:46. 

2. Kovacs MJ, Rodger M, Anderson DR, et al. Comparison of 10-mg and 5-mg warfarin initiation nomograms together with low-molecular-weight heparin for outpatient treatment of acute venous thromboembolism. A randomized, double-blind, controlled trial. Ann Intern Med 2003; 138:714. 

3. Keeling D, Baglin T, Tait C, et al. Guidelines on oral anticoagulation with warfarin - fourth edition. Br J Haematol 2011; 154:311. 

4. Garcia P, Ruiz W, Loza Munárriz C. Warfarin initiation nomograms for venous thromboembolism. Cochrane Database Syst Rev 2016; :CD007699. 

5. Ansell J, Hirsh J, Hylek E, et al. Pharmacology and management of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; 133:160S.

Failed pleurodesis

Q: Failed pleurodesis can be predicted by pleural manometry if pleural elastance is? (select one)

A) ≥5 cm H2O per liter of fluid
B) ≥10 cm H2O per liter of fluid
C) ≥15 cm H2O per liter of fluid
D)  ≥20 cm H2O per liter of fluid
E) ≥25 cm H2O per liter of fluid


Answer: D

Pleurodesis requires contact between two layers of a lung to be successful i.e., the visceral and parietal pleurae. Failed pleurodesis is a term applied if a lung failed to fully expand to the chest wall. Various causes include "trapped lung", interstitial pulmonary fibrosis (IPF) or any kind of endobronchial obstruction. In such cases, failed pleurodesis appears as pneumothorax after the procedure. One of the way to predict a failed pleurodesis is using pleural manometry pressure during thoracentesis. Pleural pressure changes is a good surrogate of pleural elastance. A final value for pleural elastance ≥19-20 cm H2O per liter of fluid removed predicts a high likelihood of a failed pleurodesis.

#pulmonary
#procedures


References:

1. Doelken P, Huggins JT, Pastis NJ, Sahn SA. Pleural manometry: technique and clinical implications. Chest 2004; 126:1764. 

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

crossreactivity of contrasts

 Q: 58 years old male is admitted to ICU due to Atrial Fibrillation associated Rapid Ventricular Rate (AF-RVR). Patient developed acute abdominal pain after a few hours of admission and requires CT scan with contrast. Patient has a previous history of allergies with shellfish and gadolinium contrast. Your next step of management? (select one)

A) Proceed with CT scan with IV contrast

B) 'Prep' patient with steroid & diphenhydramine  

Answer: A 

'CT scan with IV contrast' is an everyday affair in ICU. There are two objectives to this question. The first is to clarify the misconception that prophylactic 'preps' are needed in IV contrast for CT scan, in cases with hypersensitivity to other compounds including gadolinium contrast as well as shellfish, and topical povidone-iodine solutions. In actuality, in a strict sense, there is no such thing as "iodine allergy", a frequently used misterm. Iodine is a fundamental element in the human body.

The second objective of this case scenario is to emphasize learning the art of risk vs. benefit. In many situations like severe acute abdominal pain as in our patient with AF-RVR, it may be required to 'bite the bullet' and proceed to CT scan. Delay in many clinical situations may be detrimental to the patient.

#allergy-immunology

#radiology

References:

1. Macy EM. Current Epidemiology and Management of Radiocontrast-Associated Acute- and Delayed-Onset Hypersensitivity: A Review of the Literature. Perm J. 2018;22:17-072. doi:10.7812/TPP/17-072 

2. Schabelman E, Witting M. The relationship of radiocontrast, iodine, and seafood allergies: a medical myth exposed. J Emerg Med 2010; 39:701. 

3. Bottinor W, Polkampally P, Jovin I. Adverse reactions to iodinated contrast media. Int J Angiol. 2013;22(3):149-154. doi:10.1055/s-0033-1348885

MG in pregnancy

Q; 32 years old female in the first trimester of pregnancy is admitted to ICU with exacerbation of her Myasthenia Gravis (MG). The patient is started on pyridostigmine. This patient might require? (select one) 

 A) higher dose

 B) lower dose

Answer: A

Pyridostigmine i.e., acetylcholinesterase inhibitors stays the standard first-line treatment for MG in pregnancy. But, it may require a higher dose as renal clearance goes up in pregnancy, there is an expanded maternal blood volume, and frequent emesis. The important thing is to remember to decrease the interval of administration. Later, increase the dose if symptoms persist. Said that caution should be taken to avoid intravenous (IV) pyridostigmine just prior to delivery as it may cause uterine contractions.

#neurology

#ob-GYN

References:

1. Stafford IP, Dildy GA. Myasthenia gravis and pregnancy. Clin Obstet Gynecol 2005; 48:48.

2. Norwood F, Dhanjal M, Hill M, et al. Myasthenia in pregnancy: best practice guidelines from a U.K. multispecialty working group. J Neurol Neurosurg Psychiatry 2014; 85:538. 

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

Echodensity of mitral valve mass

 Q: A low density of mechanical mitral valve mass on echocardiogram favors? (select one)

A) Thrombus

B) Pannus

Answer: A

Echodensity can be described in two ways:

1. Qualitatively - 

• low intensity: similar to myocardial echodensity
• high-intensity: similar to the prosthetic hardware echodensity

 2. Quantitatively -

It is described as using the ratio of the intensity of mass/intensity of prosthesis. A low-intensity mass of ≤0.45 suggests a presumptive diagnosis of thrombus. 

#surgical-critical-care

#cardiology

References:

1. Barbetseas J, Nagueh SF, Pitsavos C, et al. Differentiating thrombus from pannus formation in obstructed mechanical prosthetic valves: an evaluation of clinical, transthoracic and transesophageal echocardiographic parameters. J Am Coll Cardiol 1998; 32:1410. 

2. Lin SS, Tiong IY, Asher CR, et al. Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography. Am J Cardiol 2000; 86:1097.

Barbiturate coma - side effects

 Q: Which of the following is NOT a side-effect of pentobarbital induced coma? 

 A) delay in brain death determination 

 B) need of vasopressor 

 C) aadynamic ileus 

 D) risk of ventilator-associated pneumonia 

 E) severe acidosis from ethylene-glycol toxicity 

Answer: E

The induction of barbiturate coma is a common practice in neuro-surgical ICUs. In severe cases of high intracranial pressure (ICP), it helps in decreasing cerebral metabolic demand, Cerebral Blood Flow (CBF), and cerebral blood volume. Its infusion is monitored by continuous electroencephalography (EEG) monitoring, with the objective of a burst-suppression pattern. Barbiturate coma comes with its own price of various side-effects. Due to its very long half-life, there is frequently a delay in brain death determination. Hypotension is a norm and the need for pressor(s) is universal which may lead to arrhythmias as well as organs dysfunction. It also causes ileus. Poor mucus clearance increases the risk for ventilator-associated pneumonia (VAP). Pentobarbital is often prepared in propylene-glycol (not ethylene-glycol - choice E) and longer infusions may result in severe metabolic acidosis.

The objective of the above question is to highlight the dangers of iatrogenic propylene glycol toxicity in ICUs which is used as a diluent in many intravenous infusions including phenytoin, diazepam, and lorazepam besides pentobarbital.

#pharmacology

References:

1. Zosel A, Egelhoff E, Heard K. Severe lactic acidosis after an iatrogenic propylene glycol overdose. Pharmacotherapy. 2010;30(2):219. doi:10.1592/phco.30.2.219 

2. Miller MA, Forni A, Yogaratnam D. Propylene glycol-induced lactic acidosis in a patient receiving continuous infusion pentobarbital. Ann Pharmacother 2008; 42:1502.

3.  Roberts I, Sydenham E. Barbiturates for acute traumatic brain injury. Cochrane Database Syst Rev 2012; 12:CD000033. 

4. Brain Trauma Foundation, American Association of Neurological Surgeons, Congress of Neurological Surgeons, et al. Guidelines for the management of severe traumatic brain injury. XI. Anesthetics, analgesics, and sedatives. J Neurotrauma 2007; 24 Suppl 1:S71.

Vitamins in SIBO

Q: Which of the following may be normal or elevated in a patient with Small Intestinal Bacterial Overgrowth (SIBO) syndrome? 

A) Vitamin A 

B) Vitamin B12 

C) Vitaminn K 

D) Vitamin D

E) Thiamine 

 

Answer: C 

In patients with SIBO, fat malabsorption leads to steatorrhea and deficiencies of fat-soluble vitamins. Vitamin A and D are fat-soluble vitamins. SIBO also leads to Vitamin B12 deficiency due to mucosal damage at the ileal binding site. Thiamine and nicotinamide deficiency occurs from bacterial utilization. In contrast, folate and vitamin K levels are usually either normal or elevated in SIBO patients due to bacterial synthesis. Moreover, increased intestinal permeability also contributes to either normal or elevated vitamin K levels. This may become of clinical importance in a patient who is on warfarin for anti-coagulation.

#gastroenetrology

#hematology

References:

1. Sherman P, Lichtman S. Small bowel bacterial overgrowth syndrome. Dig Dis 1987; 5:157. 

2. Conly J.M. Stein K. Worobetz L. Rutledge-Harding S. The contribution of vitamin K2 (menaquinones) produced by intestinal microflora to human nutritional requirements for vitamin K. Am J Gastroenterol. 1994; 89: 915-923

Ketamine

 Q; In dissociative sedation, a patient retains the spontaneous respirations but not the airway protective reflexes? (select one)

A) True

B) False

Answer: B

Lately, Ketamine use is on increase as a sedative agent in ICUs across the USA. This is is due to its property of causing dissociative sedation. Due to this unique property patient may appear in a trance-like cataleptic state. Ketamine also provides good analgesia. It also causes amnesia. Despite these effects, a patient retains both spontaneous respirations and airway protective reflexes. This makes it useful in non intubated patients as a sedative-infusion or for use in procedural sedation. Ketamine also keeps hemodynamic stability. 

#pharmacology

#sedation-analgesia

References:

1. Umunna BP, Tekwani K, Barounis D, Kettaneh N, Kulstad E. Ketamine for continuous sedation of mechanically ventilated patients. J Emerg Trauma Shock. 2015;8(1):11-15. doi:10.4103/0974-2700.145414 

2. Brown TB, Lovato LM, Parker D. Newton A, Fitton L. Intravenous ketamine for adult procedural sedation in the emergency department: a prospective cohort study. Emerg Med J 2008; 25:498.

3. Patrick M. Wieruszewski, PharmD; Jonathan G. Leung, PharmD, BCPS, BCPP; Sarah Nelson, PharmD, BCPS, BCCCP Ketamine Use in the Intensive Care Unit AACN Adv Crit Care (2018) 29 (2): 101–106. https://doi.org/10.4037/aacnacc2018448

tuberculin test and sarcoid

 Q: 34 years old female with a past medical history of sarcoidosis and recently immigrated from an epidemiological area with a high pulmonary tuberculosis rate is admitted to ICU with community-acquired pneumonia. CXR showed a cavitary lesion. Patient was recently tested negative for "skin TB test" at the workplace. Your next step of management?

A) Isolation

B) No isolation

Answer: A

Sarcoidosis doesn't provide a reliable skin reactivity test for the mycobacterial disease. It is not a good test to screen latent tuberculosis infection. In fact, a positive test is highly diagnostic of mycobacterial disease as sarcoidosis has diminished reactivity to TB (tuberculin) test. In other words, the tuberculin skin test has high specificity but poor sensitivity for tuberculosis in sarcoid patients.

#pulmonary

Reference:

Smith-Rohrberg D, Sharma SK. Tuberculin skin test among pulmonary sarcoidosis patients with and without tuberculosis: its utility for the screening of the two conditions in tuberculosis-endemic regions. Sarcoidosis Vasc Diffuse Lung Dis. 2006 Jun;23(2):130-4. PMID: 17937109.

Commotio cordis

Q: What is Commotio Cordis? 

Answer:  Commotio Cordis is sudden cardiac death due to chest wall impact, usually over the cardiac region. Commotio Cordis is a Latin word that means "agitation of the heart."

The objective of this question is to highlight the fact that despite not well-known, this is one of the very common causes of sudden cardiac death in young athletes. This may be due to projectile balls like in baseball, cricket, or hockey or due to the impact of a body part of other athletes in contact sports like in American football. 

Despite immediate CPR and medical treatment, mortality is very high. It is particularly fatal if the timing of impact corresponds with T-wave, conditioning "R-on-T phenomenon" resulting in ventricular fibrillation.

#cardiology

#sports-medicine

References

1.  Madias C, Maron BJ, Weinstock J, et al. Commotio cordis--sudden cardiac death with chest wall impact. J Cardiovasc Electrophysiol 2007; 18:115. 

2. Maron BJ, Estes NA 3rd. Commotio cordis. N Engl J Med 2010; 362:917. 

3. Kohl P, Nesbitt AD, Cooper PJ, Lei M. Sudden cardiac death by Commotio cordis: role of mechano-electric feedback. Cardiovasc Res 2001; 50:280. 

4. Link MS, Estes NA. Athletes and arrhythmias. J Cardiovasc Electrophysiol 2010; 21:1184. 

Tuberculous peritonitis

 Q: 44 year old male with previous histories of AIDS, cirrhosis, diabetes, underlying Kaposi sarcoma, and renal failure (on continuous ambulatory peritoneal dialysis - CAPD) is admitted in ICU with severe abdominal pain. Subsequent workup diagnosed him with tuberculous peritonitis. Which of his past medical history is the highest risk factor for tuberculous peritonitis?

A) cirrhosis 
B) peritoneal dialysis
C) diabetes mellitus
D) underlying malignancy
E) AIDS

Answer: A

One of the studies has shown the following factors in descending order as risk factors for tuberculous peritonitis. It may be hard to believe that AIDS is the lowest risk factor!

• cirrhosis,
• peritoneal dialysis
• diabetes mellitus
• underlying malignancy
• systemic corticosteroids, and 
• AIDS

#infectious-diseases

Reference:

Chow KM, Chow VC, Hung LC, et al. Tuberculous peritonitis-associated mortality is high among patients waiting for the results of mycobacterial cultures of ascitic fluid samples. Clin Infect Dis 2002; 35:409.

Index card test

 Q: Q: What is 'card test' for extubation?

Answer: Cough strength is considered to be one of the most reliable indicators of successful extubation. Cough strength is usually evident with deep suctioning of the endotracheal tube (ETT). Experts have developed some formal tests and one of the formal tests is the 'card' test. It can be performed by detaching ETT and holding a simple index card at about 2 cm away from the ETT tip. If a patient cannot moisten the card on 3-4 attempts at cough, the likelihood of failed extubation is high.

#ventilators

Reference:

Khamiees M, Raju P, DeGirolamo A, et al. Predictors of extubation outcome in patients who have successfully completed a spontaneous breathing trial. Chest 2001; 120:1262.

Factors in UGI bleed

 Q: Which of the following is likely to be present in upper gastrointestinal (UGI) bleed? (select one)

A) blood urea nitrogen to serum creatinine ratio > 20

B) blood urea nitrogen to serum creatinine ratio > 30 

Answer:  B

Predictive factors for a UGI bleed can be described in Likelihood ratios (LR). Some of the important factors with their LR are below:

• patient's history of melena (LR 5.1-5.9) 
• melenic stool on examination (LR 25)
• blood or coffee-ground material on nasogastric (NG) lavage (LR 9.6)
• ratio of blood urea nitrogen (BUN) to serum creatinine (Cr) >  30 (LR 7.5)
• tachycardia (LR 4.9)
• hemoglobin less than 8 g/dL (LR 4.5-6.2)

#gastroenterology

Reference:

Srygley FD, Gerardo CJ, Tran T, Fisher DA. Does this patient have a severe upper gastrointestinal bleed? JAMA 2012; 307:1072.