Monday, December 31, 2018

Potassium abnormality in PD

Q: Which of the following electrolyte abnormality is more common in peritoneal dialysis (PD) patients?

A) Hypokalemia
B) Hyperkalemia


Answer: A

Contrary to hemodialysis (HD) patients, hypokalemia is more common in PD patients and actually may require regular potassium repletion. For not fully understood reason, African-American patients are more prone to it. 


This paradox effect in renal patients is due to two reasons: 


1. Intraperitoneal dialysate carries glucose load resulting in subsequent insulin release and increases cellular uptake of potassium. 


2. PD patients have increase bowel potassium loss due to the chemical composition of dialysate. 


This hypokalemia is not fully benign and can be fatal particularly in the first year of the PD.



#nephrology

#electrolyteimbalance


References: 


1. Khan AN, Bernardini J, Johnston JR, Piraino B. Hypokalemia in peritoneal dialysis patients. Perit Dial Int 1996; 16:652. 

2. Xu Q, Xu F, Fan L, et al. Serum potassium levels and its variability in incident peritoneal dialysis patients: associations with mortality. PLoS One 2014; 9:e86750. 

3. Torlén K, Kalantar-Zadeh K, Molnar MZ, et al. Serum potassium and cause-specific mortality in a large peritoneal dialysis cohort. Clin J Am Soc Nephrol 2012; 7:1272.

Sunday, December 30, 2018

headache attributed to intracranial neoplasm

Q: According to proposed diagnostic criteria for a headache attributed to intracranial neoplasm by the International Headache Society, all of the following are true except

A) A headache worsened in parallel with worsening of the neoplasm 
B) Progressive 
C) Worse before going to bed 
D) Aggravated by Valsalva-like maneuvers 
E) Accompanied by nausea and/or vomiting 


Answer: C

Very recently, the International Headache Society has proposed diagnostic criteria for a headache attributed to an intracranial neoplasm.

Beside other conditions, one of the following four should be present
  •  Progressive 
  • Worse in the morning and/or when lying down 
  • Aggravated by Valsalva-like maneuvers 
  • Accompanied by nausea and/or vomiting 
Please refer to the reference for full diagnostic criteria

#oncology
#neurology


Reference:

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

Saturday, December 29, 2018

Failure of Metronidazole

Q: The cause of metronidazole failure in the treatment of Clostridioides difficile infection (CDI) is the development of resistance due to overuse? (select one) 

A) True 
B) False 


 Answer:

The actual reason behind the sub-optimal response to metronidazole in CDI is the decrease stool drug level. Metronidazole is very well absorbed and as the colonic infection starts to subside, drug get intestinally absorbed, resulting in decrease stool level and poor response. In contrast oral vancomycin or fidaxomicin are poorly absorbed resulting in higher drug stool level and excellent clinical response.


#infectiousdiseases

#gastroenterology
#pharmacology


References: 


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

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

3. Johnson S, Homann SR, Bettin KM, et al. Treatment of asymptomatic Clostridium difficile carriers (fecal excretors) with vancomycin or metronidazole. A randomized, placebo-controlled trial. Ann Intern Med 1992; 117:297. 

4. Brazier JS, Fawley W, Freeman J, Wilcox MH. Reduced susceptibility of Clostridium difficile to metronidazole. J Antimicrob Chemother 2001; 48:741.

Friday, December 28, 2018

Metformin toxicity

Q: The primary goal of  hemodialysis (HD) in Metformin toxicity is to clear the drug from circulation? (select one)

A) True

B) False


Answer: B

Metformin toxicity is unique in many ways. 


First, the dose of intake does not correlate with the level of toxicity. 


Second, Metformin by itself rarely cause the hypoglycemia, so other causes of hypoglycemia should be sought. 


Third, sodium bicarbonate in metformin-induced lactic acidosis is not very much recommended as it has shown to cause reflex vasodilation after the bolus injection. 


Fourth, the objective of HD in metformin is not to remove the drug but to blunt the acidosis, so patients may require repeat treatments. For this reason HD should be performed with bicarbonate buffer. 


 HD should be strongly considered in patients with lactate level more than 15 mmol/L, pH less than 7.10, failure to respond to conventional treatment, hemodynamic stability, liver failure, encephelopathy or kidney function deterioration.



#toxicology

#nephrology
#pharmacology


References:


1. Calello DP, Liu KD, Wiegand TJ, et al. Extracorporeal Treatment for Metformin Poisoning: Systematic Review and Recommendations From the Extracorporeal Treatments in Poisoning Workgroup. Crit Care Med 2015; 43:1716. 


2. Seidowsky A, Nseir S, Houdret N, Fourrier F. Metformin-associated lactic acidosis: a prognostic and therapeutic study. Crit Care Med 2009; 37:2191. 


3. Heaney D, Majid A, Junor B. Bicarbonate haemodialysis as a treatment of metformin overdose. Nephrol Dial Transplant 1997; 12:1046. 


4. Dell'Aglio DM, Perino LJ, Kazzi Z, et al. Acute metformin overdose: examining serum pH, lactate level, and metformin concentrations in survivors versus nonsurvivors: a systematic review of the literature. Ann Emerg Med 2009; 54:818. 

5. Lalau JD, Andrejak M, Morinière P, et al. Hemodialysis in the treatment of lactic acidosis in diabetics treated by metformin: a study of metformin elimination. Int J Clin Pharmacol Ther Toxicol 1989; 27:285. 


6. Rifkin SI, McFarren C, Juvvadi R, Weinstein SS. Prolonged hemodialysis for severe metformin intoxication. Ren Fail 2011; 33:459. 



Thursday, December 27, 2018

Blood counts in Afro-American population

Q: Hemoglobin level in African-American (AA) population is usually _______ than the hemoglobin values in comparable Caucasian populations? (select one)

A) Higher
B) Lower


Answer: B

African-American population in USA irrespective of gender tends run lower hemoglobin value than in comparable Caucasian populations by 0.5 to 1 g/dL. This may be possibly due to the high prevalence of hematologic diseases in AA population such as sickle cell disease, iron deficiency anemia and/or alpha thalassemia.


#hematology



References: 

1.  Reed WW, Diehl LF. Leukopenia, neutropenia, and reduced hemoglobin levels in healthy American blacks. Arch Intern Med 1991; 151:501. 

2.  Beutler E, West C. Hematologic differences between African-Americans and whites: the roles of iron deficiency and alpha-thalassemia on hemoglobin levels and mean corpuscular volume. Blood 2005; 106:740.

Wednesday, December 26, 2018

Docusate - MOA

Q: Docusate is a commonly used anti-diarrheal agent used in ICU. It is?  (select one)

A) A surfactant 

B) An Osmotic agent 
C) a stimulant laxatives 
D) a nerve ending stimulator
E) a bulk-forming laxative


Answer:  A

Docusate sodium is a stool softener in a layman term but medically it is a surfactant. Its mechanism of action is little more complex and interesting. It is an anionic surfactant, means a surface-active agent. It lowers the surface tension at the oil-water interface of the feces, allowing more water and lipids to enter the stool. High water and lipid content of the stool facilitates natural defecation.

Although it is a very benign medicine, it may cause contact dermatitis as a side effect.

#gastroenterology
#pharmacology


References:


1. PDR - https://www.pdr.net/drug-summary/Colace-Capsules-docusate-sodium-1023

2. Ramkumar D, Rao SS. Efficacy and safety of traditional medical therapies for chronic constipation: systematic review. Am J Gastroenterol 2005; 100:936.

Monday, December 24, 2018

Quinolone in human bites

Q: 22 year old male is admitted to ICU with early signs of sepsis after his hand gets infected due to human bite after fighting at a basketball game. Which of the following Quinolones can be used as a monotherapy?

A) Ciprofloxacin
B) Levofloxacin
C) Moxifloxacin
D) Cinoxacin
E) Quinolones should not be used in human bites


Answer: C

Moxifloxacin is one of the quinolones which has good activity against anaerobes.  Human bites involve both aerobic and anaerobic bacterias, including strep., S. aureus, Eikenella, Fusobacterium, Peptostreptococcus, Prevotella, and Porphyromonas spp. In sepsis due to human bites, parenteral antibiotics are required. The antibiotics which can be used as a monotherapy include Imipenem-cilastatin, Meropenem, Ertapenem, or Moxifloxacin.

#pharmacology
#infectiousdiseases


References: 

1. Stevens DL, Bisno AL, Chambers HF, et al. Practice guidelines for the diagnosis and management of skin and soft tissue infections: 2014 update by the Infectious Diseases Society of America. Clin Infect Dis 2014; 59:147. 

2. Kennedy SA, Stoll LE, Lauder AS. Human and Other Mammalian Bite Injuries of the Hand: Evaluation and Management. J Am Acad Orthop Surg. 2015 Jan. 23 (1):47-57.

Sunday, December 23, 2018

Criteria for Toxic Megacolon

Q: All of the following are part of the diagnosis of Toxic Megacolon except?

A) Radiographic evidence of colonic distension 
B) Fever > 38ºC 
C) Neutrophilic leukocytosis > 20,500/microL 
D) Dehydration 
E) Electrolyte disturbances


Answer:  C

The criteria of Toxic Megacolon cannot be made without the radiographic evidence of colonic distension. Despite the availability of CT scan and ultrasound, the plain radiograph is vital to make the diagnosis. This is probably due to the fact that criteria was established almost 50 years ago and still valid and easy to use in clinical practice. Usually, the transverse or right colon is found to be dilated from 6 cm up to 15 cm on supine films. If radiographic evidence is present, it does not take much to confirm the diagnosis of toxic megacolon with the addition of the following.

 PLUS at least 3 of the following:

•Fever >38ºC
•Heart rate >120 beats/min
•Neutrophilic leukocytosis >10,500/microL (only mild elevation is required)
•Anemia

PLUS at least one of the following:

•Dehydration
•Altered sensorium
•Electrolyte disturbances
•Hypotension


#gastroenterology
#surgicalcriticalcare


References:

1. Jalan KN, Sircus W, Card WI, et al. An experience of ulcerative colitis. I. Toxic dilation in 55 cases. Gastroenterology 1969; 57:68.

2. Fazio VW. Toxic megacolon in ulcerative colitis and Crohn's colitis. Clin Gastroenterol 1980; 9:389. 

Saturday, December 22, 2018

Lung abscess, immunocompromised patient and steroids

Q: Which of the following organism should be suspected and covered in lung abscess in an immunocompromised patient on prolonged glucocorticoids? 

 A) Pneumocystis pneumonia (PCP) 
 B) Staphylococcus aureus 
C) Klebsiella 
D) Nocardia 
 E) Anaerobic infection


Answer:  D

 The common organisms in lung abscess in an immunocompromised patient include Pseudomonas aeruginosa, Aspergillus, Cryptococcus spp, mucormycosis, Mycobacterium tuberculosis, PCP and nontuberculous mycobacteria.

Nocardia goes high on the list if an immunocompromised patient is on a prolonged course of glucocorticoids.


#infectiousdiseases
#pulmonary



References:

1. Beaman BL, Beaman L. Nocardia species: host-parasite relationships. Clin Microbiol Rev 1994; 7:213.

2. Ambrosioni J, Lew D, Garbino J. Nocardiosis: updated clinical review and experience at a tertiary center. Infection 2010; 38:89. 

3. Coussement J, Lebeaux D, van Delden C, et al. Nocardia Infection in Solid Organ Transplant Recipients: A Multicenter European Case-control Study. Clin Infect Dis 2016; 63:338.

Friday, December 21, 2018

an abrupt and a very severe headache associated with unilateral pulsatile tinnitus

Q: 74 year old man presented to the ED with a complaint of an abrupt and a very severe headache associated with unilateral pulsatile tinnitus and hypogeusia. On examination, the patient found to have a Horner syndrome. What is the suspected diagnosis? 


Answer: Dissection of the ipsilateral internal carotid artery

Patients with carotid artery dissection can have a variety of presentations from minor to dramatic symptoms. It can occur in any age group but more in the younger age group. Few clues to the dissection of the internal carotid artery include a headache associated with neck and face pain, amaurosis fugax, Horner syndrome, Pulsatile tinnitus, hypogeusia and sometimes deceiving migraine-like symptoms.

#neurology


Reference:

 Divjak I, Slankamenac P, Jovicevic M, Zikic TR, Prokin AL, Jovanovic A. A case series of 22 patients with internal carotid artery dissection. Med Pregl. 2011 Nov-Dec. 64(11-12):575-8.

Thursday, December 20, 2018

EKG variation in Afro-American athletes

Case: 28 year old Afro-American athlete is admitted to ICU directly from his physician office where EKG was done as part of a regular annual physical exam. Patient has no complaints, feel healthy and has no cardiac history in the family. EKGs from physician office and ICU shows "dome-shaped ST elevation with T wave inversions" (biphasic T waves) in leads V1 to V4. EKG pattern in all other leads is normal. Your diagnosis?


Answer: Afro-American athlete repolarization variant

10-15 percent of African-American athletes have a pattern of dome-shaped ST elevation with T wave inversions, sometimes appearing as biphasic T waves in leads V1 to V4. This EKG variation is a normal pattern if an athlete has no symptoms, otherwise normal physical exam or has no family history. Said that this is limited to leads V1 to V4. If abnormalities are noted in other leads, they should be investigated.


#cardiology



References:


1. Papadakis M, Carre F, Kervio G, et al. The prevalence, distribution, and clinical outcomes of electrocardiographic repolarization patterns in male athletes of African/Afro-Caribbean origin. Eur Heart J 2011; 32:2304. 

2. Sheikh N, Papadakis M, Ghani S, et al. Comparison of electrocardiographic criteria for the detection of cardiac abnormalities in elite black and white athletes. Circulation 2014; 129:1637.

Wednesday, December 19, 2018

ECMO cannulation tips

Q: If a patient is cannulated for Veno-Veno (VV) extracorporeal membrane oxygenation (ECMO) via femoral and right internal jugular (R-IJ) veins, where should the tips of cannulae lie?


Answer: 

Femoral (either right or left) vein is usually used to cannulate the drainage cannula. R-IJ vein can be used as an infusion cannula. Ideally, the tip of the femoral cannula should be at the junction of the inferior vena cava and right atrium, and the tip of the R-IJ cannula at the junction of the superior vena cava and right atrium. 

#ECMO

#hemodynamics
#pulmonary


Reference:


Pavlushkov E, Berman M, Valchanov K. Cannulation techniques for extracorporeal life support. Ann Transl Med. 2017;5(4):70.

Tuesday, December 18, 2018

Necrotizing Fascitis

Q: In necrotizing fasciitis? (select one)

 A) anesthesia precedes the skin necrosis
 B) skin necrosis precedes the anesthesia 


Answer: A

Necrotizing fasciitis can be deadly with a late diagnosis. History and physical exam provide vital clues. In susceptible cases, if anesthesia precedes the appearance of skin necrosis, it should be treated as necrotizing fasciitis, proved otherwise.

#infectiousdiseases
#physicalexam



Reference: 

Schwartz MN, Pasternack MS. Cellulitis and subcutaneous tissue infections. In: Principles and Practice of Infectious Diseases, 6th ed, Mandell GL, Bennett JE, Dolin R (Eds), Churchill Livingstone, Philadelphia 2005. p.1172.

Monday, December 17, 2018

On Polyuria

Q: All of the following are examples of "solute diuresis" except?

A) Glucosuria 
B) Resolution from azotemia 
C) Tissue catabolism 
D) Mannitol administration 
E) Nephrogenic diabetes insipidus


Answer: E

 Polyuria is defined as a urine output more than 3 Liter over 24 hours period in an adult patient. Polyuria is broadly classified into solute and water diuresis. Most of the diuresis is due to solute. Three major causes of water diuresis are
  •  Primary polydipsia
  • Central diabetes insipidus 
  • Nephrogenic diabetes insipidus 
The easiest way to differentiate between a solute or water diuresis is to look into urine osmolality. A solute diuresis usually has a urine osmolality of > 600 mosmol/kg and a water diuresis is usually has a urine osmolality < 600 mosmol/kg.

#endocrinology
#nephrology


Reference: 

Adam D Jakes, Sunil Bhandari, Investigating polyuria, BMJ 2013;347:f6772

Sunday, December 16, 2018

Antibiotic prophylaxis in COPD

Q: Which of the following antibiotics can be used as a prophylaxis in the prevention of exacerbation of chronic obstructive pulmonary disease  (COPD)?

A) azithromycin 
B) doxycycline. 
C) ciprofloxacin 
D) metronidazole 
E) sulfamethoxazole/trimethoprim


Answer: A

Azithromycin has an anti-infective as well as an anti-inflammatory properties.  Azithromycin has shown to increase the median time to first COPD exacerbation as well as the reduction in the frequency of COPD exacerbations. But this comes with a price of increased nasopharyngeal colonization with macrolide-resistant bacteria.


#pulmonary

#infectiousdiseases
#pharmacology



References:


Albert RK, Connett J, Bailey WC, et al. Azithromycin for prevention of exacerbations of COPD. N Engl J Med 2011; 365:689
.

Saturday, December 15, 2018

Enteroclysis

Q: What is the procedure called Enteroclysis? 

Answer: Enteroclysis is a procedure utilized in non-acute mechanical small bowel obstruction (M-SBO). In procedure, nasojejunal (NJ) tube is passed in the duodenum, and a large volume of air and contrast is passed into the small intestine. The procedure is closely guided by fluoroscopy. Methylcellulose, in contrast, works as a volume challenge and accentuates the effect of low-grade obstruction. This procedure can be beneficial in patients with recurrent small bowel obstruction, as enteroclysis can identify the areas of stenosis.

#procedures

#surgicalcriticalcare
#gastroenterology



References:


1. Shrake PD, Rex DK, Lappas JC, Maglinte DD. Radiographic evaluation of suspected small bowel obstruction. Am J Gastroenterol 1991; 86:175.

2. Mullan CP, Siewert B, Eisenberg RL. Small bowel obstruction. AJR Am J Roentgenol 2012; 198:W105.

Friday, December 14, 2018

Neck bruit in stroke

Q: Finding of neck bruit on physical examination in a stroke patient is a clue to which type of stroke before any radiological finding is available?

A) Intracerebral hemorrhage (ICH) 
B) Subarachnoid hemorrhage (SAH)
C) Ischemic (thrombotic)
D) Ischemic (embolic)
E) It is an irrelevant finding


Answer: C

History and physical exam can give good clues about types of strokes. 


ICH usually occurs gradually, more common in the Afro-American and Asian population, and usually, precipitate by physical activity. It carries its own risk factors like hypertension, trauma or vascular malformations. 


In contrast, SDH is well known to have a hallmark of an abrupt onset of a severe headache, classically defined as the "worst headache of life". 


Ischemic (thrombotic) stroke is usually marked by stuttering progression with periods of improvement. Neck bruit is frequently present on exam. 


Ischemic (embolic) stroke has a classic description of sudden onset with deficit maximal at onset. Classic history is precipitation by getting up at night to urinate.


#neurology

#physicalexam



References:


1. Wang MY, Mimran R, Mohit A, et al. Carotid stenosis in a multiethnic population. J Stroke Cerebrovasc Dis 2000; 9:64. 


2. Wolma J, Nederkoorn PJ, Goossens A, et al. Ethnicity a risk factor? The relation between ethnicity and large- and small-vessel disease in White people, Black people, and Asians within a hospital-based population. Eur J Neurol 2009; 16:522. 

3. Rockman CB, Hoang H, Guo Y, et al. The prevalence of carotid artery stenosis varies significantly by race. J Vasc Surg 2013; 57:327. 

Thursday, December 13, 2018

Inhaled epoprostenol and ventilator circuit

Q: What leads to a clogged ventilator circuit filter in an intubated patient due to the administration of continuous INHALED epoprostenol?


Answer: The use of inhaled epoprostenol is still considered off-label. Inhaled epoprostenol is commonly being reconstituted with glycine, which is a very viscous diluent, and may clogged the ventilator circuit. Constant vigilance is required and ventilator circuit should be changed frequently i.e, around every 4 hours. Increase resistance in ventilatory circuit may cause elevated peak airway pressures.

#pulmonary
#ventilator
#pharmacology


References:

1. Dzierba, AL, Abel, EE, Buckley, MS, Lat, I : A review of inhaled nitric oxide and aerosolized epoprostenol in acute lung injury or acute respiratory distress syndrome. Pharmacotherapy 2014; 34:279–90 

2.  De Wet, CJ, Affleck, DG, Jacobsohn, E, Avidan, MS, Tymkew, H, Hill, LL, Zanaboni, PB, Moazami, N, Smith, JR : Inhaled prostacyclin is safe, effective, and affordable in patients with pulmonary hypertension, right heart dysfunction, and refractory hypoxemia after cardiothoracic surgery. J Thorac Cardiovasc Surg 2004; 127:1058–67 

Wednesday, December 12, 2018

Chylothorax - Adjuvant Rx

Q: Which of the following drugs is said to be helpful in the management of chylothorax?

A) Corticosteroids
B) Hydralazine
C) Lopressor
D) Midodrine
E) Lisinopril


Answer: D

Midodrine is an alpha 1-adrenergic agonist and causes vasoconstriction of the lymph system. It is shown to be effective in patients who do not respond to dietary modifications and surgical intervention.


Other drug which has efficacy in chylothorax is octreotide, a somatostatin analogue. 


Other choices have no role in chylothorax.


#pharmacology

#surgicalcriticalcare


References:

1. Liou DZ, Warren H, Maher DP, et al. Midodrine: a novel therapeutic for refractory chylothorax. Chest 2013; 144:1055. 

2. Use of an alpha-1 adrenoreceptor agonist in the management of recurrent refractory idiopathic chylothorax. Chest 2018; 154:e1. 

Tuesday, December 11, 2018

Critical illness polyneuropathy and myopathy

Q:  Critical illness myopathy (CIM) and critical illness polyneuropathy (CIP) include all of the following except

A) Symmetric limb weaknesses
B) Ventilatory muscle weakness
C) Extraocular muscles spared
D) Reduced tendon reflexes
E)  Distal muscles more affected 


Answer: E

CIM and CIP affect a large population of critically ill patients who stay more than 2 weeks in ICU. Symptoms are usually overlapped. All of the above choices are correct except E.  The most dreaded clinical feature is flaccid quadriparesis where proximal muscles are more affected than distal muscles. Early mobilization and physical therapy, avoiding prolonged exposure to steroids and neuro-muscular blockers are considered key interventions.


#earlymobilization

#neurology



Reference:


Latronico N, Bolton CF. Critical illness polyneuropathy and myopathy: a major cause of muscle weakness and paralysis. Lancet Neurol 2011; 10:931.

Monday, December 10, 2018

PHQ-9

Q: Patient Health Questionnaire-nine (PHQ-9) is a scoring system to determine severity for?

A) Depression 
B) Anxiety 
C) Pain
D) Sedation 
E) Delirium 


Answer: A

PHQ-9 is a questionnaire to determine the severity of depression. If a patient scores more than 20, it determines severe depression and may warrants ICU admission, particularly if reported with suicidal ideation.


It consists of nine questions, and each question can have a maximum of 3 points, ranging from 0 to 3, depending on severity reported by a patient - not determined by a provider.



The score was developed by Drs. Robert L Spitzer, Janet BW Williams, Kurt Kroenke, and colleagues, with an educational grant from Pfizer, Inc. It has no copyrights and no permission is required to reproduce, translate, display or distribute.

#psychiatry



Reference:


Spitzer RL, Kroenke K, Williams JBW. Patient Health Questionnaire Study Group. Validity and utility of a self-report version of PRIME-MD: the PHQ Primary Care Study. JAMA. 1999;282:1737–44.

Sunday, December 9, 2018

MRI in acute and subacute SDH

Q: what makes subacute Sub Dural Hematoma (SDH) appear brighter on the Magnetic Resonance Imaging (MRI) than acute SDH?


Answer:  Acute, sub-acute, and chronic SDH are classified according to time periods. SDH happening within 48 hours are labeled as acute, up to two weeks as subacute and afterward as chronic SDH. This classification determines the clinical management.

The most important clinical determination clinicians have to make is between acute and subacute/chronic SDH. The acute clot only has the presence of deoxyhemoglobin and appears hypointense on T2-weighted images. Over days deoxyhemoglobin degrades to methemoglobin, and appears bright on both T1 and T2-weighted images.


#neurosurgery
#neurology


Reference:

Atlas SW, Thulborn KR. Intracranial hemorrhage. Magnetic Resonance Imaging of the Brain and Spine. 3rd ed. Philadelphia, Pa: Lippincott Williams & Wilkins; 2002. 773-832.

Saturday, December 8, 2018

Risk factors - pyogenic liver abscesses

Q: Which group of drugs are considered risk factors in the development of pyogenic liver abscesses? 


Answer: Proton-pump inhibitors (PPIs)

Some of the major risk factors in the development of pyogenic liver abscesses are diabetes mellitus, underlying hepatobiliary disease, underlying pancreatic disease, history of liver transplant, and regular use of proton-pump inhibitors.


#hepatology

#pharmacology
#infectiousdiseases


References:


1.  Lin HF, Liao KF, Chang CM, et al. Correlation between proton pump inhibitors and risk of pyogenic liver abscess. Eur J Clin Pharmacol 2017; 73:1019.

2. Kaplan GG, Gregson DB, Laupland KB. Population-based study of the epidemiology of and the risk factors for pyogenic liver abscess. Clin Gastroenterol Hepatol 2004; 2:1032. 


3. Thomsen RW, Jepsen P, Sørensen HT. Diabetes mellitus and pyogenic liver abscess: risk and prognosis. Clin Infect Dis 2007; 44:1194. 

Friday, December 7, 2018

Predicting AKI in ICU

Q: All of the following are part of predicting Acute Kidney Injury (AKI) within 48 hours of admission to ICU except?

A) History of chronic kidney disease (CKD) 
B) History of hypertension (HTN)
C) History of coronary heart disease (CHD)
D) PH less than 7.20 
E) Mechanical ventilation


Answer: D

Recently a score 1 is developed and validated to predict AKI within 48 hours of admission to ICU. There are ten components to it including CKD, HTN, CHD, chronic liver disease, heart failure, n
ephrotoxin exposure, sepsis, mechanical ventilation, and anemia. 

Level of PH included is less than 7.30.


This score has  95 percent negative predictive value if  patient's score is less than 5.



#nephrology


Reference:

1. Malhotra R, Kashani KB, Macedo E, et al. A risk prediction score for acute kidney injury in the intensive care unit. Nephrol Dial Transplant 2017; 32:814.

Thursday, December 6, 2018

cholesterol emboli and renal failure

Q: After cardiac catheterization, all of the following support the diagnosis of Atheroembolism, popularly known as 'cholesterol crystal emboli' except?

A) Resolving renal failure
B) Blue toes 
C) Livedo reticularis 
D) Retinal hollenhorst plaques
E) Eosinophilia 


Answer: A

One of the dreaded complications of cardiac catheterization is 'cholesterol emboli' as it bears high morbidity. Acute kidney injury is not uncommon after cardiac catheterization but it is mostly due to contrast-induced nephropathy and usually resolved in a week with appropriate management. Persistent kidney failure with other clinical finding described in other choices usually is a feature of 'cholesterol emboli. Almost 40 percent of these patients develop End Stage Renal Disease (ESRD), and many of these patients have a low survival.


#procedure

#nephrology
#cardiology


Reference: 


Scolari F, Ravani P, Gaggi R, et al. The challenge of diagnosing atheroembolic renal disease: clinical features and prognostic factors. Circulation 2007; 116:298.

Tuesday, December 4, 2018

Code, PE and tPA route

Q: In patients with Cardio-pulmonary arrest due to massive pulmonary embolism (PE) thrombolytic therapy is preferred via 

A) Central  Venous Catheter (CVC)
B) Peripheral catheter (PV)


Answer: A

Usually, thrombolytic therapy (tissue Plasminogen Activator - tPA) in PE is given via peripheral venous catheter to avoid bleeding from puncture sites, but if thrombolytic therapy is used during cardiopulmonary arrest due to PE, it is preferred to use CVC. If CVC is not available, ideally should be quickly inserted under ultrasound to avoid multiple punctures.


Patients in cardiac arrest have poor peripheral perfusion as well as right-sided heart failure, which may limit the efficacy of thrombolytic therapy. Also, it is suggested that a bolus dose of thrombolytic therapy through the CVC increases the concentration of the drug at the site of the thrombus, quickly resolving the embolism.

#pulmonary

#procedure
#hemodynamic


References: 


1. Gulati V, Brazg J. Central Venous Catheter-directed Tissue Plasminogen Activator in Massive Pulmonary Embolism. Clin Pract Cases Emerg Med. 2018;2(1):67-70. 

2. Pillarisetti J, Gupta K. Massive pulmonary embolism with shock: role of thrombolysis using central venous access. J Invasive Cardiol. 2012;24(12):E321–4

Dig and OTC compounds

Q: 53-year-old male with a history of ischemic cardiomyopathy presented to ED with dizziness. EKG was found to have a third degree AV block. Laboratory work showed Digoxin level of 5.4 ng/mL. Patient reports not to change the doses of any of his medications, albeit he stops taking a lot of over the counter self-help herbal remedies in last one month. Withdrawal of which of the following compounds may increase the chances of "Dig. Toxicity"?

A) Garlic 
B) Saw palmetto 
C) St. John's Wort 
D)  Bilberry
E) Aloe


Answer: C

Taking Digoxin with St. John's Wort decreases its effect via decrease absorption. St. John's wort contains hypericum which induces intestinal P-glycoprotein/Multiple Drug Resistance (MDR)-1 drug transporters gene.

Clinicians without the knowledge of the patient's over the counter intake of supplements may increase the dose to obtain a clinically therapeutic effect. Subsequently, if this balance disrupted, may cause a sudden rise in serum digoxin level.

#pharmacology
#cardiology


Reference: 

Johnte A et al. Pharmacokinetic interaction of digoxin with an herbal extract from St John's wort (hypericum perforatum). Clin Pharmacol Ther 1999 Oct 66 338345

Monday, December 3, 2018

IV-Fluid in sickle cell crisis

Q: In a euvolemic patient with sickle cell crisis normal saline is not a fluid of choice for intravenous maintenance. Why? 


 Answer: In a euvolemic patient with sickle cell crisis the fluid of choice for intravenous fluid maintenance is either quarter-normal or half-normal saline. This is because patients with sickle cell disease cannot excrete sodium effectively, and quickly develop hypernatremia. Serum hypernatremia causes red cell dehydration, resulting in more "sickling" of the cells.

#hematology

#electrolytes



Reference:


Okpala I. The management of crisis in sickle cell disease. Eur J Haematol. 1998;60:1–6.

Sunday, December 2, 2018

tPA in pregnancy

Q: Alteplase (tPA) in pregnancy is? (select one)

A) Relative contraindication
B) Absolute contraindication


Answer: A

Alteplase (tPA) does not cross the placenta, but the risk exists due to hemorrhagic complications, which may lead to added complications in a pregnant patient with premature labor, placental abruption, or fetal demise. But in pregnant patients with life-threatening stroke, strong consideration should be given to tPA therapy.


#neurology

#OB-Gyn


References:


1. Leonhardt G, Gaul C, Nietsch HH, et al. Thrombolytic therapy in pregnancy. J Thromb Thrombolysis 2006; 21:271. 

2.  Murugappan A, Coplin WM, Al-Sadat AN, et al. Thrombolytic therapy of acute ischemic stroke during pregnancy. Neurology 2006; 66:768. 

3.  Demchuk AM. Yes, intravenous thrombolysis should be administered in pregnancy when other clinical and imaging factors are favorable. Stroke 2013; 44:864. 

4.  Demaerschalk BM, Kleindorfer DO, Adeoye OM, et al. Scientific Rationale for the Inclusion and Exclusion Criteria for Intravenous Alteplase in Acute Ischemic Stroke: A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke 2016; 47:581.

Saturday, December 1, 2018

Stool markers for Inflammatory Bowel Diseases

Q: Which "stool marker" can differentiate between inflammatory bowel disease (IBD) and any functional bowel disease? 


 Answer:  Calprotectin 

Calprotectin and lactoferrin are two stool markers for inflammatory bowel disease. Out of these two, calprotectin is the most used. If fecal calprotectin is normal, a diagnosis of inflammatory disease is practically ruled out. Also, if it is elevated, it has a sensitivity of about 93 percent and specificity of 96 percent to have IBD. Calprotectin is also used to monitor disease activity and flare-ups. 


#gastroenterology



References:


1. Sipponen T. Diagnostics and prognostics of inflammatory bowel disease with fecal neutrophil-derived biomarkers calprotectin and lactoferrin. Dig Dis 2013; 31:336. 


2.  Mosli MH, Zou G, Garg SK, et al. C-Reactive Protein, Fecal Calprotectin, and Stool Lactoferrin for Detection of Endoscopic Activity in Symptomatic Inflammatory Bowel Disease Patients: A Systematic Review and Meta-Analysis. Am J Gastroenterol 2015; 110:802. 


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


4. van Rheenen PF, Van de Vijver E, Fidler V. Faecal calprotectin for screening of patients with suspected inflammatory bowel disease: diagnostic meta-analysis. BMJ 2010; 341:c3369.

Friday, November 30, 2018

Rescue therapies in Thyroid storm

Q: All of the following has been used or suggested to have beneficial effects in the management of Thyroid storm except?

A) Plasmapheresis 
B) Lithium 
C) Cholestyramine 
D) Glucocorticoids 
E) Aspirin


Answer: E

The objective of the above question is to highlight the possible role of plasmapheresis and lithium in the management of thyroid storm as adjuvant use of steroid and cholestyramine are relatively known in this disease.


Also, it is universally known to stay away from aspirin in thyroid storm as it releases thyroxine from protein binding sites.

Plasmapheresis is particularly useful if a thyroid storm is caused by a drug overdose but it can be attempted as a last-ditch therapy. Plasmapheresis is suggested in thyroid storm as theoretically can remove cytokines, antibodies, and thyroid hormones from plasma. 1

Lithium can acutely block the release of thyroid hormone, and this side effect of lithium can be utilized in a thyroid storm. 2

#endocrine



References:

1. Muller C, Perrin P, Faller B, et al. Role of plasma exchange in the thyroid storm. Ther Apher Dial 2011; 15:522.

2. Carroll R, Matfin G. Endocrine and metabolic emergencies: thyroid storm. Ther Adv Endocrinol Metab. 2010;1(3):139-45.

Thursday, November 29, 2018

Hypokalemia and hepatic encephalopathy

Q: How diuresis can directly contribute to hepatic encephalopathy in liver cirrhosis patients?



Answer: Diuresis lead to hypokalemia and contraction alkalosis.

1. Hypokalemia increases renal ammonia synthesis

2. Alkalemia increases the conversion of charged ammonium (NH4+) to unionized ammonia (NH3). Unionized ammonia can readily penetrate neurons and can deteriorate hepatic encephalopathy


#hepatology

#electrolytes


References:


Gabduzda GJ, Hall PW 3rd. Relation of potassium depletion to renal ammonium metabolism and hepatic coma. Medicine (Baltimore) 1966; 45:481.

Wednesday, November 28, 2018

'Massive' GI bleed

Q: How the "massive" upper or lower gastrointestinal (UGI/LGI) bleed is defined? 


 Answer: Unlike hemoptysis, it is hard to quantify the GI bleed. UGI or LGI bleed is considered 'massive' if requires transfusion of 4 units of blood or more in 24 hours period. Other definitions described are hemodynamic instability with systolic blood pressure (SBP) less than 90 mmHg, and the initial decrease in hematocrit of 6 g/dL or less.

#gastroenterology 




References:

1. Millward SF. ACR Appropriateness Criteria on treatment of acute nonvariceal gastrointestinal tract bleeding. J Am Coll Radiol 2008; 5:550. 


2. Zuccaro G Jr. Management of the adult patient with acute lower gastrointestinal bleeding. American College of Gastroenterology. Practice Parameters Committee. Am J Gastroenterol 1998; 93:1202.

Tuesday, November 27, 2018

Physical exam & stenosis of AV-Graft

Q: Which part of the hand is best to examine the "thrill" of an Arterio-venous graft (AVG) in hemodialysis (HD) patient?


Answer: Palm

A patent arteriovenous graft for HD patients should have a considerable thrill, which is best palpable with the palm. Although thrill should have both a systolic and a diastolic component, that's often hard to distinguish. It usually feels like a "soft, continuous, diffuse thrill." 

It is more pronounced near the arterial anastomosis, but in case, if it feels more accentuated at any other place of the course of the graft, it raises the possibility of stenosis.

#physicalexam
#nephrology



References: 

1.  Beathard GA. Physical examination of the dialysis vascular access. Semin Dial 1998; 11:231.

2. Leon C, Orozco-Vargas LC, Krishnamurthy G, et al. Accuracy of physical examination in the detection of arteriovenous graft stenosis. Semin Dial 2008; 21:85.

Monday, November 26, 2018

BNP in obese patients

Q: B-type natriuretic peptide (BNP) in obese patients tend to be? (select one)

A) Lower than non-obese patients 
B) higher than non-obese patients


Answer: A

Obese patients tend to have lower plasma BNP level than patients with normal Body Mass Index (BMI). Despite various studies the exact reason behind this disparity is not known.


Clinical significance: It may deceive a clinician with severity of heart failure.

#cardiology
#laboratory-medicine


References:


1. Das SR, Drazner MH, Dries DL, et al. Impact of body mass and body composition on circulating levels of natriuretic peptides: results from the Dallas Heart Study. Circulation 2005; 112:2163.


2. Mehra MR, Uber PA, Park MH, et al. Obesity and suppressed B-type natriuretic peptide levels in heart failure. J Am Coll Cardiol 2004; 43:1590. 

3. Wang TJ, Larson MG, Levy D, et al. Impact of obesity on plasma natriuretic peptide levels. Circulation 2004; 109:594. 

4. McCord J, Mundy BJ, Hudson MP, et al. Relationship between obesity and B-type natriuretic peptide levels. Arch Intern Med 2004; 164:2247. 

5. Horwich TB, Hamilton MA, Fonarow GC. B-type natriuretic peptide levels in obese patients with advanced heart failure. J Am Coll Cardiol 2006; 47:85. 


Sunday, November 25, 2018

Dengue virus vaccination

Q; 53 years old male is recovering in ICU from severe dengue virus infection after his trip to Columbia. He asked for possible vaccination against Dengue virus (DENV). Infection from Dengue virus automatically provide lifelong immunity against it and doesn't require protection, and should only be administrated to people with no history or laboratory evidence of the previous infection.

A) True
B) False


Answer: B

Contrary to expectations, administration of Dengue vaccine to people without any previous exposure can do more harm than benefit. But it should be administrated to people with previous experience of DENV, as the chances of severity go up in the second infection.


Treatment is mostly preventive, and if acquired, supportive with fluid resuscitation. 



#infectiousdiseases



References:


http://www.who.int/immunization/diseases/dengue/q_and_a_dengue_vaccine_dengvaxia/en/ (World Health Organization)

Saturday, November 24, 2018

On Plateau Pressure

Q: The plateau pressure (Pplat) on the ventilator should be measured with a pause at? (select one) 

A) end-inspiration 
B) end-expiration 


 Answer: A

Pplat is the reflection of static compliance of the whole respiratory system taking into account of lung parenchyma, chest wall, as well as an abdominal effect on respiratory mechanics, so the Pplat is measured while there is no airflow.

Knowing that Pplat should be measured at pause and at end-inspiration.


#pulmonary

#ventilators


References:


1. Stenqvist O. Practical assessment of respiratory mechanics. Br J Anaesth 2003; 91:92. 


2. Tobin MJ. Respiratory monitoring. JAMA 1990; 264:244. 

3. Marini, JJ. Lung mechanics determinations at the bedside: instrumentation and clinical applications. Respir Care 1990; 35:669.

Friday, November 23, 2018

eosinophilia in severe trichinellosis

Q: Absence of eosinophilia in severe trichinellosis is a? (select one) 

A) Good sign 
B) Bad sign 


 Answer:

 Massive eosinophilia which may go up to 90% of leucocytosis is a hallmark of clinical trichinellosis. It starts during the second week of the muscle stage and peaked at the third or fourth week. Said that there is no correlation between the clinical course of the disease and the severity of eosinophilia. Disappearance or absence of eosinophilia in severe clinical trichinellosis is actually a poor prognostic sign.


#infectiousdiseases

#laboratory-medicine



References:

1. Kociecka W. Trichinellosis: human disease, diagnosis and treatment. Vet Parasitol 2000; 93:365.

2. Vu Thi N, Trung DD, Litzroth A, et al. The hidden burden of trichinellosis in Vietnam: a postoutbreak epidemiological study. Biomed Res Int 2013; 2013:149890.

Thursday, November 22, 2018

Colorimetric capnography in NGT placement

Q: Colorimetric capnography is a reliable method to identify misplacement of nasogastric tube (NGT) position in mechanically ventilated patients? 

A) Yes 
B) No 


Answer:

Although not frequently used for this purpose, a  meta-analysis of five studies showed a colorimetric capnography to have a sensitivity of 88 to 100 percent and a specificity of 99 to 100 percent to identify misplacement of the nasogastric tube into the airway in mechanically ventilated patients.

#nutrition
#procedure
#pulmonary


Reference:

Bennetzen LV, Håkonsen SJ, Svenningsen H, Larsen P. Diagnostic accuracy of methods used to verify nasogastric tube position in mechanically ventilated adult patients: a systematic review. JBI Database System Rev Implement Rep 2015; 13:188.

Wednesday, November 21, 2018

Horner Syndrome

Q: Horner Syndrome associated with Arm pain, hand weakness (typical of brachial plexus type lesions) suggest lesion at? 

 A) brainstem 
 B) cervicothoracic cord 
C) lung apex 
D) cavernous sinus 
E) internal carotid dissection


Answer: C

The classic triangle of Horner syndrome is

  • ptosis
  • miosis
  • anhidrosis
Although in about 40 percent of cases no reason can be identified, it can be a manifestation of a serious underlying lesion/disease. Associated features help in locating the lesion site.
  •  Brainstem lesion is marked by diplopia, vertigo, ataxia, and lateralized weakness
  •  Lesion in cervicothoracic cord gives myelopathic features like bilateral or ipsilateral weakness, long tract signs, and bowel and bladder impairment 
  •  Lesions in the apex of the lung is associated with arm pain and/or hand weakness typical of brachial plexus lesions 
  •  Lesion in cavernous sinus gives Ipsilateral extraocular pareses, particularly a sixth nerve palsy, in the absence of other brainstem signs 
  •  An isolated Horner syndrome accompanied by neck or head pain is probably due to internal carotid dissection

#physicalexam
#neurology



Reference:

Maloney WF, Younge BR, Moyer NJ. Evaluation of the causes and accuracy of pharmacologic localization in Horner's syndrome. Am J Ophthalmol 1980; 90:394.

Tuesday, November 20, 2018

Definition of neutropenic fever

Q: What is the definition of fever in neutropenic patients per the Infectious Diseases Society of America? 


 Answer: The Infectious Diseases Society of America defines fever in neutropenic patients as either

  • a single oral temperature of 101°F, or 
  • a temperature of 100.4°F sustained over 60 minutes


#infectiousdiseases




Reference:

Freifeld AG, Bow EJ, Sepkowitz KA, et al. Clinical practice guideline for the use of antimicrobial agents in neutropenic patients with cancer: 2010 update by the infectious diseases society of america. Clin Infect Dis 2011; 52:e56.

Monday, November 19, 2018

Obstetrics Critical Illnesses

Q: All of the following favors the diagnosis of preeclampsia except?

A) Severe elevation of LDH
B) significant hypertension 
C) severe liver dysfunction 
D) severe elevation of AST 
E) illness after a gestation age of 20 weeks


Answer: A

In obstetric emergencies sometimes it is difficult to recognize the difference between look-alike clinical conditions. But few features are pathognomic to certain conditions.


Thrombotic thrombocytopenic purpura (TTP) is technically defined by a less than 10% activity of ADAMTS13 (but the test may take few weeks to be available). Similarly, hemolytic uremic syndrome (HUS) is dominant by a clinical feature of acute renal failure. 

One of the major differentiation between preeclampsia and TTP/HUS can be done on the basis of two relatively simple laboratory tests i.e. Lactate Dehydrogenase (LDH) and aminotransferase (AST). LDH is usually severely elevated in TTP/HUS while the severe elevation of AST is the feature of preeclampsia.


#obstetrics
#hepatology  



References: 


1.  Fyfe-Brown A, Clarke G, Nerenberg K, et al. Management of pregnancy-associated thrombotic thrombocytopenia purpura. AJP Rep 2013; 3:45. 

2. Allford SL, Hunt BJ, Rose P, et al. Guidelines on the diagnosis and management of the thrombotic microangiopathic haemolytic anaemias. Br J Haematol 2003; 120:556.

Sunday, November 18, 2018

2 other essentials of CVA

Q: All of the following should be confirmed prior to administration of alteplase in acute stroke except? 

 A) The time window is met 
B) Eligibility criteria is fulfilled 
 C) Hypoglycemia is ruled out 
D) Two intravenous lines, preferably 2 large bores, are placed 
E) Ideal body weight is measured


 Answer:

 Besides all the 'checklist' marked for the administration of alteplase, there are two other essentials that should be checked 

 1) A dedicated intravenous line is required for alteplase. 
 2) The dose should be calculated of actual body weight

 The dose of alteplase dose is 0.9 mg/kg, with a maximum dose of 90 mg, 10% of which is given as an upfront bolus and the remainder is infused over next hour. 

 #neurology
 #pharmacology 


 Reference: 

 Michaels AD, Spinler SA, Leeper B, et al. Medication errors in acute cardiovascular and stroke patients: a scientific statement from the American Heart Association. Circulation 2010; 121:1664.

Saturday, November 17, 2018

"Dig effect on EKG"

Q: Describe the effects of Digoxin on EKG? 

Answer: Following could be the EKG effects secondary to Digoxin, popularly known as "Dig. effect". One or more may be present. 


  • ST depression with a characteristic “sagging” appearance 
  • Flattened, inverted, or biphasic T waves. 
  • Shortened QT interval 
  • Mild PR interval prolongation of up to 240 ms
  • Prominent U waves 
  • Peaking of the terminal portion of the T waves 
  • J point depression
#cardiology


Reference:

Heather Wetherell. Digoxin and the heart. August 2015. Br J Cardiol 2015;22:96–7

Friday, November 16, 2018

Murmur of Aortic Dissection

Q:  Murmur of acute aortic dissection can be best heard at? (select one)

A) right sternal border 
B) left sternal border 


 Answer: A

The objective of the above question is to bring into light the 'location difference' of aortic regurgitation murmur secondary to aortic dissection and primary aortic valve disease. 

  •  The murmur of aortic regurgitation due to the aortic dissection is best audible along the right sternal border 
  • The murmur of aortic regurgitation due to the primary aortic valve disease is best audible along the left sternal border 

 Other clinical signs help to distinguish between the two clinical conditions, as the presentation of acute aortic dissection is relatively dramatic associated with acute sharp tearing chest pain often radiating to back, a wide pulse pressure, hypotension, possible pulse deficit, and neurological symptoms.

#cardiology

#surgicalcriticalcare


References: 


1. Nienaber CA, Eagle KA. Aortic dissection: new frontiers in diagnosis and management: Part I: from etiology to diagnostic strategies. Circulation 2003; 108:628. 

2. Hagan PG, Nienaber CA, Isselbacher EM, et al. The International Registry of Acute Aortic Dissection (IRAD): new insights into an old disease. JAMA 2000; 283:897.