Monday, November 30, 2020

CXR in ADHF

 Q: Presence of unilateral pulmonary edema on chest X-ray (CXR) points toward which valvular heart disease?

A) mitral regurgitation 

B) mitral stenosis 

C) aortic regurgitation 

D) aortic stenosis 

E) tricuspid regurgitation


Answer: A

CXR finding in acute decompensated heart failure (ADHF) usually consists of bilateral interstitial markings in a well-known "butterfly" pattern. Other typical findings in CXR are cardiomegaly, peribronchial cuffing, and interlobular septal thickening. Blood flow pattern and alveolar edema pattern also provides a clue. There is usually an upper zone redistribution of blood flow with alveolar edema mostly filling the perihilar and lower-lobe airspace, and the periphery generally spared in the mid and upper lung zones. 

 In case, signs of ADHF are present but CXR shows unilateral pulmonary edema, it is most probably caused by an eccentric mitral regurgitation.

#cardiology

#radiology


References:

1. Cardinale L, Volpicelli G, Lamorte A, et al. Revisiting signs, strengths and weaknesses of Standard Chest Radiography in patients of Acute Dyspnea in the Emergency Department. J Thorac Dis 2012; 4:398. 

2. Attias D, Mansencal N, Auvert B, et al. Prevalence, characteristics, and outcomes of patients presenting with cardiogenic unilateral pulmonary edema. Circulation 2010; 122:1109.

Sunday, November 29, 2020

TCH and SAH

 Q: One of the most common cause of Thunderclap Headache (TCH) is subarachnoid hemorrhage (SAH)?

A) True

B) False


Answer: A

The two most common causes of TCH are subarachnoid hemorrhage (SAH) and reversible cerebral vasoconstriction syndromes (RCVS). Other less common causes include but not limited to are meningitis, complicated sinusitis, cerebral venous thrombosis, cervical artery dissection, acute hypertensive crisis, posterior reversible leukoencephalopathy syndrome (PRES), intracerebral hemorrhage, and ischemic stroke.

Almost half of the patients with SAH have a presenting symptom of TCH. SAH is almost certain unless ruled out if it presents in association with impaired consciousness, neck stiffness, nausea, vomiting, exertion immediately preceding the onset of TCH, hypertension,  occipital headache, and history of smoking. Any TCH should be evaluated with concern.

#neurology


References:

1. Ducros A, Bousser MG. Thunderclap headache. BMJ 2013; 346:e8557. 

2.  Headache Classification Committee of the International Headache Society (IHS) The International Classification of Headache Disorders, 3rd edition. Cephalalgia 2018; 38:1. 

3. Schwedt TJ. Thunderclap Headache. Continuum (Minneap Minn) 2015; 21:1058. 

4. Perry JJ, Stiell IG, Sivilotti ML, et al. Clinical decision rules to rule out subarachnoid hemorrhage for acute headache. JAMA 2013; 310:1248.

5. Linn FH, Rinkel GJ, Algra A, van Gijn J. Headache characteristics in subarachnoid haemorrhage and benign thunderclap headache. J Neurol Neurosurg Psychiatry 1998; 65:791.

Saturday, November 28, 2020

PAP and CXR

 Q: 44 years old male with a history of myelodysplastic syndrome is admitted to ICU with shortness of breath. Report of Chest X-ray (CXR) from ED reads possible pulmonary alveolar proteinosis (PAP). CXR in PAP usually shows prominent air bronchograms? 

A) True 

B) False 


Answer:

Although the process of PAP is alveolar in distribution, air bronchograms are not seen. If air bronchograms are visible, other disease processes should be strongly considered. 

Few features of chest x-ray in PAP are bilateral symmetric alveolar opacities in a "batwing" distribution means located centrally in mid and lower lung zones. Sparing of lungs may be present by a thin lucent band sharply outlining the diaphragm and the heart. Segmental atelectasis is common due to thick lipoproteinaceous material. Patients with chronic PAP may progress towards fibrosis.

#pulmonary


References:

1. Claypool WD, Rogers RM, Matuschak GM. Update on the clinical diagnosis, management, and pathogenesis of pulmonary alveolar proteinosis (phospholipidosis). Chest 1984; 85:550. 

2. Miller PA, Ravin CE, Smith GJ, Osborne DR. Pulmonary alveolar proteinosis with interstitial involvement. AJR Am J Roentgenol 1981; 137:1069. 

3. Prakash UB, Barham SS, Carpenter HA, et al. Pulmonary alveolar phospholipoproteinosis: experience with 34 cases and a review. Mayo Clin Proc 1987; 62:499.

Friday, November 27, 2020

DT and respitaory change

 Q: Patients with delirium tremens (DT) usually develop? (select one) 

A) respiratory alkalosis 

 B) respiratory acidosis 


 Answer: A

Patients with DT develops hyperventilation causing respiratory alkalosis. This is an important development as this leads to a clinically significant decrease in cerebral blood flow. The overall effect is correlated with the level of clouding of the sensorium in DT. This is another reason phenytoin is not very effective in seizures in DT.

Said that interestingly, there is no association between a decrease in cerebral blood flow and hallucinations or degree of tremors. It should be remembered that alcoholic hallucinosis and DT are two different phenomena. Alcoholic hallucinosis occurs early in the case of alcohol withdrawal and is not a cause or result of DT. .

#toxicology


References:

1. Berglund M, Risberg J. Regional cerebral blood flow during alcohol withdrawal related to consumption and clinical symptomatology. Acta Neurol Scand Suppl 1977; 64:480. 

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. 

3.  Wood E, Albarqouni L, Tkachuk S, et al. Will This Hospitalized Patient Develop Severe Alcohol Withdrawal Syndrome?: The Rational Clinical Examination Systematic Review. JAMA 2018; 320:825.

Wednesday, November 25, 2020

valvular hear disease and high cholesterol

 Q: Signs of which valvular heart disease should be looked for in physical examination if a patient has a history of familial hypercholesterolemia?

Answer: Aortic

The aortic valve and root abnormalities due to premature malignant atherogenesis is a complication of familial hypercholesterolemia. For the bedside clinician, it should be of importance to know that a cardiac CT scan is more sensitive than echocardiography to detect aortic valve calcification. Atheromatous plaques in the root and ascending aorta may also be common. Said that mitral valvulopathy can also be present but less prevalent than aortic abnormalities.

#cardiology


References:

1. A. Kawaguchi, C. Yutanid, and A. Yamamoto, “Hypercholesterolemic valvulopathy: An aspect of malignant atherosclerosis,” Therapeutic Apheresis, vol. 7, no. 4, pp. 439–443, 2003. 

2. G.-J. R. T. Kate, S. Bos, A. Dedic et al., “Increased Aortic Valve Calcification in Familial Hypercholesterolemia Prevalence, Extent, and Associated Risk Factors,” Journal of the American College of Cardiology, vol. 66, no. 24, pp. 2687–2695, 2015. 

3. K. L. Chan, K. Teo, J. G. Dumesnil, A. Ni, and J. Tam, “Effect of lipid lowering with rosuvastatin on progression of aortic stenosis: results of the aortic stenosis progression observation: measuring effects of rosuvastatin (ASTRONOMER) trial,” Circulation, vol. 121, no. 2, pp. 306–314, 2010. 

4. C. Pitsavos, K. Toutouzas, J. Dernellis et al., “Aortic stiffness in young patients with heterozygous familial hypercholesterolemia,” American Heart Journal, vol. 135, no. 4, pp. 604–608, 1998.

Tuesday, November 24, 2020

media for organism growth

 Q: In laboratory, which media is used to detect Haemophilus influenzae? (select one) 

 A) Blood agar 

 B) Chocolate agar 

 C) MacConkey agar


Answer: B

The objective of this question is to emphasize the clinical relevance of ordering sputum culture. Laboratory personnel is usually trained to employ different media to grow different organisms but providing a little relevant history helps expedite the accurate result. For instance, Legionella pneumophila requires a specialized buffered charcoal-yeast extract (BCYE) agar media. 

Blood agar is used for gram-positive cocci (GPC) and for most of the gram-negative rods (GNR) useful.

Chocolate agar is used for Haemophilus influenzae and other fastidious organisms. 

MacConkey agar is used for gram-negative bacteria to allow further classification into lactose-positive or negative organisms.


References:

1. Muraki M, Kitaguchi S, Ichihashi H, Tsuji F, Ohmori T, Haraguchi R, Tohda Y. [Use of transport medium in sputum bacterial culture examination of lower airway infection]. Nihon Kokyuki Gakkai Zasshi. 2006 Jun;44(6):425-30. Japanese. PMID: 16841712. 

2. Rogers GB, Daniels TW, Tuck A, et al. Studying bacteria in respiratory specimens by using conventional and molecular microbiological approaches. BMC Pulm Med. 2009;9:14. Published 2009 Apr 15. doi:10.1186/1471-2466-9-14 

3. Recommendations of the Clinical Subcommittee of the Medical/Scientific Advisory Committee of the Canadian Cystic Fibrosis Foundation. Microbiological processing of respiratory specimens from patients with cystic fibrosis. Can J Infect Dis. 1993;4(3):166-169. doi:10.1155/1993/989086

Monday, November 23, 2020

FUO

 Q: By definition which one of the following is NOT correct for Fever of Unknown Origin (FUO)?

A) Fever higher than 38.3ºC on several occasions 

 B) Duration of fever for at least two weeks 

 C) Uncertain diagnosis after one week of study in-patient


Answer: B

FUO was first described 90 years ago 1, and although many amendments and modifications have been proposed, there is no change in the three basic principles of FUO in the last 50 years 2.

  • Fever higher than 38.3ºC on several occasions 
  • Duration of fever for at least three weeks, and
  • Uncertain diagnosis after one week of study in-hospital
#infectious-diseases


References: 

1. Alt HL, Barker MH. Fever of unknown origin. JAMA 1930; 94:1457. 

2. PETERSDORF RG, BEESON PB. Fever of unexplained origin: report on 100 cases. Medicine (Baltimore) 1961; 40:1.

Sunday, November 22, 2020

Fomepizole

 Q: Fomepizole can be given orally? (select one) 

A) True 

B) False 

 

Answer:

Fomepizole is the best available antidote for Ethylene Glycol and Methanol poisoning. It is preferred to be given intravenously (IV). The loading dose is 15 mg/kg followed by 10 mg/kg every 12 hours. It is dialyzable and the dose needs to be adjusted for hemodialysis. If an IV line can not be obtained it can be given orally. The bioavailability is almost equivalent. Also, the dose is similar. In a crossover trial of PO and IV route of administration, similar blood levels were obtained 2.

#toxicology


References:

1. Mégarbane B, Houzé P, Baud FJ. Oral fomepizole administration to treat ethylene glycol and methanol poisonings: advantages and limitations. Clin Toxicol (Phila) 2008; 46:1097; author reply 1097.

2. Marraffa J, Forrest A, Grant W, Stork C, McMartin K, Howland MA. Oral administration of fomepizole produces similar blood levels as identical intravenous dose. Clin Toxicol (Phila). 2008 Mar;46(3):181-6. doi: 10.1080/15563650701373796. PMID: 18344099.

Saturday, November 21, 2020

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.

Friday, November 20, 2020

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:

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.

Thursday, November 19, 2020

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.

Wednesday, November 18, 2020

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.

Tuesday, November 17, 2020

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.

Monday, November 16, 2020

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.

Sunday, November 15, 2020

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.

Saturday, November 14, 2020

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.

Friday, November 13, 2020

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.

Thursday, November 12, 2020

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

Wednesday, November 11, 2020

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.

Tuesday, November 10, 2020

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.

Monday, November 9, 2020

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.

Sunday, November 8, 2020

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.

Saturday, November 7, 2020

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).

Friday, November 6, 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.

Thursday, November 5, 2020

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:

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.

Wednesday, November 4, 2020

Pain in acute infectious thyroiditis

Q: Pain in acute infectious thyroiditis is usually? (select one)

A) localized in neck
B) generalized over neck


Answer:  A

The characteristic pain in acute infectious thyroiditis is usually sudden, tender on touch, and unilateral. Mass can be sometimes felt as fluctuant. Fever and chills are almost universal. Differential diagnoses include hemorrhage into a thyroid nodule or subacute thyroiditis. Workup requires an ultrasound and fine-needle aspiration biopsy.

#infectious-disease
#endocrinology
#physical-exam


Reference:

Paes JE, Burman KD, Cohen J, et al. Acute bacterial suppurative thyroiditis: a clinical review and expert opinion. Thyroid 2010; 20:247.

Tuesday, November 3, 2020

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.

Monday, November 2, 2020

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.

Sunday, November 1, 2020

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.