Q: Cardiology service ordered to transfuse one unit of pRBC in a 52 year old male with CHF. Orders were written to give blood slowly. How long can a blood component can be hang? 


 Answer: Once the blood component is spiked for transfusion it should be infused in no more than 4 hours.

Q: During apnea test for brain death evaluation, how much oxygen should be deliverd

Answer:  8 L/min

Before brain death evaluation, preoxygenate with 100% oxygen for 30 minutes and disconnect the ventilator. Place a cannula at the level of carina and delivers 8 L/mi

 

_{Click here to see a sample Apnea test protocol here}

Q: 60 year old male with ESRD (End Stage Renal Disease), and with history of A. Fib. is recently started on Pradaxa (Dabigatran). Patient presented with acute lower GI bleed. Patient took last dose about 12 hours ago. Knowing that reversal for Pradaxa is not available to you, what could be your option here? 


Answer: Hemodialysis (HD) 

Though Hemodialysis may not be fully effective but upto 60% of Dabigatran can be removed via hemodialysis and may provide some relief. Patient with already available access for HD should be given advantage of it with close volume monitoring and replacement. 

 For patients with creatinine clearance (CrCl) more than 30 mL/min, the recommended dose of PRADAXA is 150 mg twice daily. For patients with severe renal impairment (CrCl 15-30 mL/min), the recommended dose of PRADAXA is 75 mg twice daily.

Q: Ciprofloxacin is not a good choice in patients with myasthenia gravis. Why?

Answer:  Ciprofloxacin is now known for more than 20 years to cause worsening of myasthenia gravis, including muscle weakness and breathing problems - and may require ventilatory support.

Other drugs which make MG worse include Beta-blockers, Lithium, Procainamide, Verapamil, Prednisone and Neuromuscular blocking agents.

Reference: http://www.accessdata.fda.gov/drugsatfda_docs/label/2011/019537s075,020780s033lbl.pdf

Q: How Alcohol septal ablation is performed for hypertrophic cardiomyopathy (HCM)? 


 Answer: Alcohol septal ablation is not very different in technique from regular coronary angioplasty except here artifical occlusion is performed! After localizing the the septal artery feeding the hypertrophied muscle, a small amount of absolute alcohol is infused into the artery to produce infarction. Resulting chest pain can be treated with analgesics and sedatives. About 5-10% of patients may require permanent pacemaker. 

This procedure should be performed by cardiologists with specific training in the procedure. This procedure is also called 'Sigwart procedure' as it was first performed by British cardiologist Ulrich Sigwart in 1994.

Q: Vancomycin can be given as? 

A) Intravenous infusion 
B) via oral route (PO)
 C) Via inhaled Nebulizer
 D) via topical application
 E) via drops in eye/ears 
 F) All of the above 


 Answer: F 

Vancomycin can be given via all the routes as described above. The objective of above question is to emphasis the inhaled administration of Vancomycin as other routes are fairly known to ICU physicians. 

Lately, there has been various reports where inhaled Vancomycin has been used successfully to treat MRSA particularly in cystic Fibrosis patients.

Q: Which one is more effective - IV Chloramphenicol or PO Chloramphenicol?


Answer: PO Chloramphenicol

Interestingly and unlike most other drugs PO Chloramphenicol is more effective than IV preparation of Chloramphenicol.

Pure chloramphenicol does not dissolve in water so it has to be prepare with succinate ester. Chloramphenicol succinate ester is an inactive prodrug and must first be hydrolysed to chloramphenicol; however, during hydrolysis 30% of the drug is lost.

To be effective, the dose needs to be increased to be equivalent to the oral dose!

Q: What is Peek sign?


Answer: Myasthenia gravis causes weakness, predominantly in bulbar, facial, and extra-ocular muscles.

The peek sign is manifestation of orbicularis fatigue. On lid closure to command, the orbicularis muscle initially may achieve lid apposition; however, as the patient continues to try to keep the eyes forcefully closed over a minute, the orbicularis oculi fatigues, and sometimes the lids separate to show a rim of sclera, with the patient appearing to "peek" at the examiner. With profound orbicularis fatigue, the cornea may become visible.

The peek sign can also be seen with VII nerve palsies.

Q: During traumatic spinal tap, protein may also get introduce into the CSF beside RBCs. What rule of thumb may help in differentiating between traumatic protein tap vs otherwise unsuspected neurologic disease?


Answer: An approximation of 1 mg of protein for every 750 RBCs may be used as a guide for probable traumatic tap. It is advisible to repeat spinal tap to confirm diagnosis.

A high CSF protein level, can be a clue to demyelinating polyneuropathies.

Q: What is Maddrey’s modified Discriminant Function (mDF) and its clinical implication?

 

Answer: American College of Gastroenterology defines severity of alcoholic hepatitis as a modified Discriminant Function(mDF). If score is more or equal to 32 and/or hepatic encephalopathy, it identifies the cutoff for severity. This is calculated as

mDF = 4.6 (PTpatient–PTcontrol)+ serum bilirubin (µmol/l)/17.

mDF more/= 32 and/or hepatic encephalopathy was associated with a 65% 28-day survival in placebo treated patients. While those with a score less than 32 had a survival of 93%.

American College of Gastroenterology recommends prednisolone should be used in patients with severe alcoholic hepatitis ( where mDF more/= 32) in whom the diagnosis is certain.

Caspofungin data in recipients of liver transplant

One recent study did retrospective analysis of death, adverse events (AE), fungal infections, and hepatic function among recipients of liver transplantation (105 patients) at high risk of fungal infection who received prophylactic treatment with caspofungin.

Post-transplant patients at high risk for fungal infection are commonly defined by the presence of at least one of the following: (i) re-transplantation; (ii) re-operation; (iii) renal dysfunction. However, in our practice, patients are also considered at high risk for developing fungal infections if they present with the following: (iv) fever of unknown origin; (v) hypothermia; (vi) positive random culture for fungus at the time of transplant (bile and/or ascites); (vii) sepsis; (viii) use of vasopressors; (ix) re-intubation, during the first hospitalization after liver transplant; (x) prolonged intubation (  more than 24 h), and (xi) acute respiratory distress syndrome, until negative fungal cultures are obtained.

Exact conditional logistic regression was used to compare the risk of death, AEs, and fungal infections between patients who received caspofungin, other antifungal drugs, and no antifungal drugs.

Analyses were then performed with SAS 9.1 (SAS Institute Inc., Cary, NC, USA). Patients were between 27 and 72 yr old (mean = 55), with two-thirds male and three-quarters Caucasian. Sixteen patients received caspofungin (11 preventively), and 32 received other antifungal (26 preventively).

There were no proven fungal infections among the patients who received caspofungin, three infections among patients who received other antifungal (3/26 = 12%), and 14 infections among patients who were not preventively treated (14/45 = 31%). These infection rates were significantly different across the three groups (p = 0.029), with caspofungin and other antifungal preventive treatment comparable (p = 0.540), and both better than no preventive treatment at all (OR = 0.15, p = 0.049, for caspofungin versus no preventive treatment; OR = 0.29, p = 0.085, for other antifungal versus no preventive treatment).

Caspofungin appears to be an effective preventive agent against fungal infections when used in recipients of liver transplant designated as high risk for fungal infection. Usage of caspofungin in these patients does not carry an apparent increase in risk of death or acute cellular rejection, although we observed a significantly higher risk of AEs, especially acute renal failure (p = 0.001), in patients who received this agent.



Reference: Clin Transplant. 2011 Jul-Aug;25(4):569-75.

Q: 48 year old female who is on "Cipro" for last 5 days due to severe urinary tract infection (UTI), is now complaining of diplopia. What is your concern?



Answer; Damage may be permanent

Ciprofloxacin has been repoted to cause diplopia which may be permanent. It may also cause complete loss of vision and impaired color vision but those are usually reversible.

5th generation cephelsporin!

Ceftobiprole is a fifth-generation cephalosporin antibiotic with activity against MRSA, Pseudomonas aeruginosa, and enterococci. It is on Fast track for FDA approval. Ceftobiprole has already been approved for use in Canada and Switzerland.

Ceftobiprole is the first, broad-spectrum, anti-MRSA cephalosporin. It is also the first of antimicrobials to include anti-MRSA and anti-Pseudomonas activity in the spectrum of its coverage - providing single coverage for both. The dosing ris 500 mg IV every 8 hours or every 12 hours. Dosing adjustments may be necessary in patients with renal insufficiency.

Q: 28 year old female with previous history of postpartum cardiomyopathy is again admitted to ICU with 28 weeks pregnancy and shortness of breath. Cardiology service wrote for Cardiac MRI. Nusre needs your input on safety in view of pregnancy? 

 Answer: Cardiac MRI is safe to perform after first trimester of pregnancy. So far, there is no evidence found that MRI is dangerous to a fetus. Only precaution required is to avoid MRI contrast in pregnant patients. 

Also, Cardiac MRI is safe with coronary stents, joint replacements, sternal wires, and prosthetic heart vales.

2 less appreciated factor in Variceal bleed beside obstruction 


Obstruction of portal venous flow, whatever the etiology, results in a rise in portal venous pressure. This is a well know documented etiology. But there are 2 other factors which may play part in increase portal pressure and variceal bleed. 

1. Increase Endothelin-1 (ET-1) which is a powerful vasoconstrictor synthesized by sinusoidal endothelial cells and causes increased hepatic vascular resistance of cirrhosis and the development of liver fibrosis. 

2. Nitric Oxide (NO) is a known vasodilator substance that is synthesized by sinusoidal endothelial cells. In the cirrhotic liver, the production of NO is decreased. 


 Gupta TK, Toruner M, Chung MK, Groszmann RJ. Endothelial dysfunction and decreased production of nitric oxide in the intrahepatic microcirculation of cirrhotic rats. Hepatology. Oct 1998;28(4):926-31.

Endotracheal Tube Cuff Pressure

Endotracheal tube cuff pressure must be kept within an optimal range that ensures ventilation and prevents aspiration while maintaining tracheal perfusion.

One study published in AJCC about a year ago looked into 32 orally intubated patients receiving mechanical ventilation for two 12-hour shifts labelled as randomized control and intervention condition respectively.

Continuous cuff pressure monitoring was initiated, and the pressure was adjusted to a minimum of 22 cm H₂O. Caregivers were blinded to cuff pressure data.

• Usual care was provided during the control condition.
• During the intervention condition, cuff pressure alarm or clinical triggers guided the intervention.

It was found that

• During the control condition, 51.7% of cuff pressure values were out of range compared with 11.1% during the intervention condition (P less than .001).
• During the intervention, a mean of 8 adjustments were required, mostly to add air to the endotracheal tube cuff.
• During the control condition, cuff pressure decreased over time (P less than .001).
  
  

Evaluation of an Intervention to Maintain Endotracheal Tube Cuff Pressure Within Therapeutic Range - Am J Crit Care March 2011 , vol. 20 no. 2 109-118

Q: What is the 20-30-40 rule in myasthenic crisis? 


 Answer: The 20-30-40 rule is the most helpful and reliable indicator to decide when intubation is necessary in Myasthenia Crisis. 

•  vital capacity less than 20ml/kg; 
•  peak inspiratory pressure less than −30 cm H2O 
•  peak expiratory pressure less than 40 cm H20

Q: What is the conversion of Po Pyridostigmine (Mestinon) to IV Pyridostigmine in patients with Myasthenic Crisis, who is intubated now and is NPO? 

 Answer: Conversion of PO pyridostigmine to IV pyridostigmine is 30:1

Q: What precaution should be taken while giving Pralidoxime as antidote for organophosphate poisoning?

Answer: It should be given slowly over 30 minutes. If given as bolus it may precipitate respiratory or cardiac arrest. Dose is 30 mg/kg. 

 If intravenous access is not available, it may be given as intramuscular or subcutaneous injection.

Q: 17 year old male presented to ER after he accidentally ingested only 1 teaspoon of oil of wintergreen at his farmhouse. Initially he decided to stay away due to minor ingestion but brought to ER by parents 'just for checkup'. What is your concern?


Answer: Salicylate Toxicity

One teaspoon of oil of wintergreen (98% methyl salicylate) contains 7000 mg of salicylate (nearly 90 baby aspirins). It should be considered as true toxicology emergency.

Q: Give 7 risk factors for development of Zygomycosis 1?

Answer: Zygomycosis or Mucormycosis 1 is a fungal infection which is found mostly in diabetic patients. It is found to be associated with some interesting risks factors

1. Acidosis
2. Renal insufficiency
3. Diarrhea
4. Aspirin intake

5. Glucocorticoids intake

6. Deferoxamine intake

7. Splenectomy

1. Zygomycosis is the broadest term to refer to infections caused by bread mold fungi and includes mucormycosis, phycomycosis and basidiobolomycosis. "Mucormycosis" and "zygomycosis" are used interchangeably.

Daptomycin and Eosinophilic pneumonia

Daptomycin may cause eosinophilic pneumonia, somewhere between 2 to 4 weeks after initiation of daptomycin therapy. in 2010 seven confirmed cases were reported and 36 were suspicious of it. Symptoms resolved when daptomycin was discontinued but recurred in two patients when the drug was restarted.

Eosinophilic pneumonia should be suspected in patients receiving daptomycin who develop new or worsening fever, cough or dyspnea. Peripheral eosinophilia may or may not be present, but BAL eosinophil counts are usually elevated. The primary treatment is discontinuation of daptomycin, along with respiratory support and, +/- , steroids.

 Q: Zosyn (Piperacillin/tazobactam) need to be adjusted in renal failure patients on hemodialysis. Does it need to be adjusted in patients on CVVHD?


Answer: NO

Dose Zosyn (Piperacillin/tazobactam) does not need to be adjusted in renal failure patients on CVVHD. It would be as like a patient with normal kidney function.

In patients on HD dose is usually: 2.25 g IV Q8h
In patients on CVVHD, dose is usually: 3.375 g IV Q6h or 4.5g IV Q8h

Classification of CKD (chronic kidney disease)

Normal kidney function – GFR above 90mL/min/1.73m² and no proteinuria
CKD1 – GFR above 90mL/min/1.73m² with evidence of kidney damage
CKD2  – GFR of 60 to 89 mL/min/1.73m² with evidence of kidney damage
CKD3  – GFR of 30 to 59 mL/min/1.73m²
CKD4  – GFR of 15 to 29 mL/min/1.73m²
CKD5  - GFR less than 15 mL/min/1.73m²
CKD5D - patients with CKD5 and requiring dialysis

 Q: 58 year old male with renal failure and travelling from europe presented to your ER with digitoxin (not digoxin) toxicity, shown by various blocks on EKG. Patient has been precribed digitoxin (not available in USA) due to its advantage of elimination via liver. What is your option here?

Answer: Digitoxin is mainly eliminated via the liver, and thus not affected by decrease in renal function like digoxin. But, Anti-digoxin antibody fragments, the specific antidote for digoxin toxicity, is similarly effective in life threatening digitoxin toxicity.

Q: It is a common practice to give calcium to counteract aarrhythmias. But in which condition, it may not be a good move or actually, it may be harmful to the patient?

Anwer: In a digitalized patient

Digoxin inhibits the Na⁺/K⁺-ATPase(exchanges 2 K for 3Na) in the cardiac myocyte by competing with potassium,and causes intracellular sodium concentration to increase. This then leads to an accumulation of intracellular calcium by blocking the Na⁺-Ca⁺⁺ exchange system.

In patients on Digoxin, if more calcium is given it can lead to more intracellular calcium in mycocyte leading to what has been described as cardiac tetany due to prolonged depolarisation.

Q: What is Purple toe syndrome?

Answer:  It is a rare complication that may occur usually within first 2 months  of commencement of warfarin treatment. Recently, it has been reported after 1 year of warfarin therapy1.

With anti coagulation, minor deposits of cholesterol break loose and flow into the feet, which causes a blueish purple and painful toe. It  typically affect the big toe, but it can affects other parts of the feet as well.

Treatment is discontinuation of warfarin.

Further read: Talmadge DB, Spyropoulos AC (2003). "Purple toes syndrome associated with warfarin therapy in a patient with antiphospholipid syndrome". Pharmacotherapy 23 (5): 674–7. Link: http://www.ncbi.nlm.nih.gov/pubmed/12741443

1. Late Onset Purple Toe Syndrome With Warfarin Successfully Treated With Fondaparinux - American Journal of Therapeutics:, November 2011 - Volume 18 - Issue 6 - pp e277-e279