Q: What are the 2 major kinds of Dialysates used in CRRT?

Answer:

1.  Lactate based Dialysate solution

2.  8.4% bicarbonate based dialysate

Lactate is commonly used as buffer. In conditions where inadequate lactate metabolism takes place (eg. in liver failure) the bicarbonate based dialysate is preferred. However, recent studies suggest that bicarbonate-buffered replacement fluids can improve acid-base status and reduce cardiovascular events better than lactate fluids. Both fluids should contain electrolytes in concentrations aiming for a physiologic level and taking into account preexisting deficits or excess and all input and losses.

Q: Succinylcholine and Rocuronium are the 2 most commonly used neuro-muscular blockades during intubation in ICUs. In which category of patients, Rocuronium should be use with precaution?

Answer: Asthma

There is considerable risk of allergic reaction to the drug group, non-depolarizing neuromuscular blocking drugs - particularly Rocuronium in some patients with asthma.  

Reference:  Burburan SM, Xisto DG, Rocco PR (June 2007). "Anaesthetic management in asthma". Minerva Anestesiologica 73 (6): 357–65.

Q: What are the 3 major risk factors for Vasoplegic syndrome in post-CABG patients?

Answer:

• The long initial Cardiopulmonary Bypass (CPB) time,
• use of an angiotensin converting enzyme inhibitor, and
• use of a beta-blocker

Reference:

Levin MA, Lin HM, Castillo JG, Adams DH, Reich DL, et al. (2009) Early on-cardiopulmonary bypass hypotension and other factors associated with vasoplegic syndrome. Circulation 120: 1664-1671.

Q: Which anti-epilectic drug can be use as an antidote in Tacrolimus Toxicity?

A) Phenytoin

B) Levetiracetam,

C) Carbamazepine

D) diazepam

E) Toprimate

Answer: A

Tacrolimus is metabolized by the CYP3A4 isoenzyme. Tacrolimus is subject to numerous drug-drug interactions. CYP3A4/PGP inhibitors may increase tacrolimus concentrations, whereas inducers may decrease tacrolimus concentrations. Phenytoin and Phenobarbital are commonly used antiepileptics and potent enzyme inducers. Another well known inducer is Rifampin.

No treatment recommendations exist for tacrolimus toxicity, as hemodialysis, plasma exchange, gastric lavage or activated charcoal are only minimally effective. Phenytoin and phenobarbital also have the additional benefit of seizure prevention as neurologic toxicities, including seizure and coma, are well documented with tacrolimus. 




References:

1. Arin S. Jantz, Samir J. Patel, Wadi N. Suki, Richard J. Knight, Arvind Bhimaraj, and A. Osama Gaber - Case Reports in Transplantation, Volume 2013 (2013)

2. R. E. Quirós-Tejeira, I. F. Chang, L. J. Bristow, S. J. Karpen, and J. A. Goss, “Treatment of acute tacrolimus whole-blood elevation with phenobarbital in the pediatric liver transplant recipient,” Pediatric Transplantation, vol. 9, no. 6, pp. 792–796, 2005.

3. G. E. McLaughlin, M. Rossique-Gonzalez, B. Gelman, and T. Kato, “Use of phenobarbital in the management of acute tacrolimus toxicity: a case report,” Transplantation Proceedings, vol. 32, no. 3, pp. 665–668, 2000.

4. Z. Karasu, A. Gurakar, J. Carlson et al., “Acute tacrolimus overdose and treatment with phenytoin in liver transplant recipients,” Journal of Oklahoma State Medical Association, vol. 94, no. 4, pp. 121–123, 2001.

5. K. Wada, M. Takada, T. Ueda et al., “Drug interactions between tacrolimus and phenytoin in Japanese heart transplant recipients: 2 case reports,” International Journal of Clinical Pharmacology and Therapeutics, vol. 45, no. 9, pp. 524–528, 2007.

Q: What precaution should be taken while calculating dose for Phenytoin (Dilantin) for an obese patient?

Answer:

In obese patients, it is common to use mistakenly actual body weight - but ideal body weight should be used for dosing calculations for Dilantin infusion.

Q:  Should highly active antiretroviral therapy be prescribed in critically ill HIV-infected patients during the ICU stay?

Answer: Yes

At least one study, looked into this question and found a lower death rate over 6 months in critically ill HIV-infected patients taking HAART during ICU stay.

Reference:

Agnes Meybeck, Lydie Lecomte, Michel Valette, Nicolas Van Grunderbeeck, Nicolas Boussekey, Arnaud Chiche, Hugues Georges, Yazdan Yazdanpanah and Olivier Leroy - Should highly active antiretroviral therapy be prescribed in critically ill HIV-infected patients during the ICU stay? A retrospective cohort study -  AIDS Research and Therapy 2012, 9:27

Q:  What is the mean level of Troponin I elevation in Subarachnoid Hemorrhage (SAH)?

Answer:   0.93

At least one study showed that the mean troponin level in subarachnoid hemorrhage was 0.93 (range, 0.01-25.8 ng/mL). But, Troponin I elevation after SAH is not an independent predictor of in-hospital mortality. 

Reference:

Gupte M, John S, Prabhakaran S, Lee VH. - Troponin elevation in subarachnoid hemorrhage does not impact in-hospital mortality.- Neurocrit Care. 2013 Jun;18(3):368-73.

Q:  After how many hours of air travel, it usually becomes a risk factor for pulmonary embolism (PE)?

Answer: After about 4 hours

Hard to predict but, The PIOPED II study described travel of 4 hours or more in the previous month as a one risk factor for PE. 


Reference:

Stein PD, Beemath A, Matta F, Weg JG, Yusen RD, Hales CA, et al. Clinical characteristics of patients with acute pulmonary embolism: data from PIOPED II. Am J Med. Oct 2007;120(10):871-9.

Q:  Fluoroquinolones are of considerable clinical importance because of their ability to cause prolongation of the QT interval and consequently causing Torsades de pointes (TdP). Which Fluoroquinolone is known to be the least and which Fluoroquinolone is known to be the worst offender?

Answer: Ciprofloxacin appears to be associated with the lowest risk for QT prolongation and the lowest TdP  occurrence. And, moxifloxacin carries the greatest risk of QT prolongation. Fluoroquinolones prolong the QT interval by blocking voltage-gated potassium channels.

Reference:

Briasoulis A1, Agarwal V, Pierce WJ.- QT prolongation and torsade de pointes induced by fluoroquinolones: infrequent side effects from commonly used medications - Cardiology. 2011;120(2):103-10

Q: Which one group of antibiotics (other than Vancomycin) has shown to increase the risk of Vancomycin-resistant Enterococcus (VRE)?

Answer: Cephalosporin

Use of Cephalosporin has been found to increase the risk for colonization and infection by VRE. Restriction of cephalosporin usage has shown to be associated with decreased VRE infection and transmission in hospitals.

Reference:

Chavers, LS.; Moser, SA.; Benjamin, WH.; Banks, SE.; Steinhauer, JR.; Smith, AM.; Johnson, CN.; Funkhouser, E. et al. (Mar 2003). "Vancomycin-resistant enterococci: 15 years and counting". J Hosp Infect 53 (3): 159–71.

Tetanus Ophistotonus

(Following pearl is contributed by

Dr Yash Javeri
Director
Apex Healthcare Consortium, Delhi, India

Secretary SCCM Delhi, India
Organizing Secretary DCCS, APCC)

Tetanus is caused by tetanospasmin which is a neurotoxin.Its a rare entity in developed world. History of wound and possible contamination in unvaccinated individuals is classic. Tetanus is characterized by a clinical triad of rigidity, muscles spasms, and, in more severe cases, autonomic dysfunction.The characteristic presentation of  tetanus is muscle rigidity and spasms.Jaw stiffness followed by spasms of jaw muscle is called trismus is characteristic of tetanus.Muscle spasms are progressive and may include a characteristic arching of the back known as opisthotonus as seen in the video.The spasm are triggered by any sort of stimuli. The disease can involve spasms of the vocal cords leading to respiratory failure.

Patient should be placed in restful environment with quietest possible conditions. Sedation, paralysis with curare like agents and mechanical ventilation are mainstay of therapy. Penicillin,20 MU intravenously in daily divided dose help eradicate toxins.

Q: What is the basic physiology which allows Pulmonary Artery Catheter (PAC) (swan-Ganz catheter) to measure left atrial pressure while catheter is still in pulmonary artery?

Answer: It is the large compliance of the pulmonary circulation, which allows an indirect measure of the left atrial pressure, while catheter is still in pulmonary artery. When  balloon is inflated (wedged) in pulmonary artery, it occludes the branch of the pulmonary artery. When this occurs, the pressure in the distal port of PAC rapidly falls, and after several seconds, reaches a stable lower value that is very similar to left atrial pressure (normally about 8-10 mmHg).

“Berlin definition” of ARDS

“Berlin definition” of ARDS is a consensus panel's new definition and severity classification system for acute respiratory distress syndrome (ARDS). It aims to simplify the diagnosis and better prognosticate outcomes. It was published in JAMA, online May 21, 2012. It took into account cohort of 4,400 patients from past randomized trials.

Major departure from 1994 classification of ARDS was, there is no need to exclude heart failure in the new ARDS definition. Patients with high pulmonary capillary wedge pressures can still have ARDS. The new criterion is that respiratory failure simply be “not fully explained by cardiac failure or fluid overload,” in the physician’s best clinical judgment. An “objective assessment“– meaning an echocardiogram was highly recommended. The new Berlin definition for ARDS would also categorize ARDS as being mild, moderate, or severe:

• Mild is P/F ratio of 200 – 300 with predicted mortality of 27%
• Moderate is P/F ratio of100 – 200 with predicted mortality of 32%
• Severe is P/F ratio less than 100 with predicted mortality of  45%

In 'Berlin definition', clinical variables that are widely believed to be important such as static compliance, radiographic severity and PEEP more than 10 — were not predictive of mortality or other clinical outcomes.

The panel’s findings, endorsed by the European Society of Intensive Care Medicine, the American Thoracic Society (ATS) and the Society of Critical Care Medicine (SCCM), emerged from meetings in Berlin to try to address the limitations of the earlier AECC definition.

Optimum PEEP

.

Link: http://www.youtube.com/watch?v=_LZOekO5BeI

Q: Nurse call you to report that patient's blood on draw appears to be bluish. What would be your concern?

Answer: Methemoglobinemia

Drugs are the most common cause of Methemoglobinemia in ICU including dapsone, trimethoprim, sulfonamides, local anesthetics, metoclopramide and iNO (commonly used in cardio-vascular ICUs).

It gives the blood a bluish or chocolate-brown color.

Treatment is methylene blue 1% solution 1 to 2 mg/kg administered intravenously slowly over five minutes. Supplemental oxygen should be added.

Q: 52 year old male with ESRD is admitted to ICU with septic shock. Patient is started on CRRT. Patient has previous history of A.fib. Pt. went into RVR (Rapid ventricular rate). Cardiology service started IV amiodarone. Is Amiodarone dialyzable?

Answer: No

Amiodarone is eliminated primarily by hepatic metabolism and biliary excretion. Desethylamiodarone (DEA) is the major active metabolite of amiodarone. Neither amiodarone nor DEA is dialyzable.

Q: Which antiepileptic works good for arrhythmia due to digoxin (cardiac glycosides) acute toxicity?

Answer: Phenytoin

Interestingly, literature in this regard is very old but has been well described.

1. Bashour FA, Edmonson RE, Gupta DN, Prati R. Treatment of digitalis toxicity by diphenylhydantoin (Dilantin). Dis Chest. 1968 Mar;53(3):263–270

2. B H Rumack, R R Wolfe, and H Gilfrich - Phenytoin (diphenylhydantoin) treatment of massive digoxin overdose. - Br Heart J. Apr 1974; 36(4): 405–408.

Q: Asterixis is an hallmark of hepatic failure. What other conditions may also carry this clinical sign?

Answer:  Asterixis  can also be observed in

• renal failure and azotemia, 
• Hypercarbic respiratory failure
• After  IV phenytoin infusion
• Patients addicted to narcotics

Q: What is the recommended target for blood sugar control in fresh post-op cardiac surgery patients?

Answer: The Society of Thoracic Surgeons supports a target glucose of less than 180 mg/dL using intravenous insulin for at least the first 24 hours postoperatively, with a target of less than 150 mg/dL if their ICU stay exceeds 3 days because of comorbidities.

Reference:

Lazar HL, McDonnell M, Chipkin SR, Furnary AP, Engelman RM, Sadhu AR. The Society of Thoracic Surgeons practice guideline series: Blood glucose management during adult cardiac surgery. Ann Thorac Surg. Feb 2009;87(2):663-9

Q: At what point, during management of DKA (Diabetes Ketoacidosis), addition of Dextrose should be considered, if ketosis persists?

Answer: 250 mg/DL

The 2011 'Joint British Diabetes Societies guideline' recommends the intravenous infusion of insulin at a weight-based fixed rate until ketosis has subsided. Should blood glucose fall below 250 mg/dL, 10% glucose should be added to allow for the continuation of fixed-rate insulin infusion.

Reference:

Savage MW, Dhatariya KK, Kilvert A, Rayman G, Rees JA, Courtney CH, et al. Joint British Diabetes Societies guideline for the management of diabetic ketoacidosis. Diabet Med. May 2011;28(5):508-15.

A note on importance of high vigilance for Boerhaave syndrome

Diagnosis of Boerhaave syndrome is difficult as about one third of all cases of Boerhaave syndrome are clinically atypical. Even with clinical signs, Boerhaave syndrome is usually misdiagnosed as acute myocardial infarction, pancreatitis, pleuritis, pericarditis, Aortic dissection or pneumothorax etc. Radiographic studies should be promptly obtained.

Overall mortality is estimated to be around 35%, making it the most lethal perforation of the GI tract. The best outcomes are associated with early diagnosis and definitive surgical management within 12 hours of rupture. If intervention is delayed longer than 24 hours, the mortality rate rises to higher than 50% and to nearly 90% after 48 hours. Left untreated, the mortality rate is close to 100%.

Q: On which day after initiation of empiric antibiotic therapy, de-escalation should be considered?

Answer:  3 - 5 days

For patients who have suspicion of infection, early and appropriate therapy - and probably aggressive empirical therapy - is required at the first sign of infection. Although, the initial choice of antimicrobial therapy is critical to the clinical outcomes of patients, it is also imperative to start de-escalation of antibiotics therapy as emerging data is showing benefit in mortality rate, or at least no worse outcome.

De-escalation therapy based on APACHE II score can be safely applied with good clinical outcomes, even in those patients with negative cultures.

A note on volume based Enteral feed

Critically ill patients placed on enteral nutrition (EN) are usually underfed as most of them are placed on "Frequency-based Enteral nutrition" (FBF). Interruptions are frequent due to various reasons.

 A "volume-based feeding" (VBF) allows to adjust the infusion rate to make up for interruptions in delivery. Studies have shown that VBF strategy is safe and improves delivery to better meet caloric requirements than the standard more commonly used frequency-based strategy.

Q: What is the rule to remember if blood type compatibility is done for plasma products?

Answer: 

Compatibility testing is not strictly necessary for plasma products like FFP or cryo-precipitate, but if possible, is given as ABO compatible. Rule to remember is - compatibility is reversed for plasma products, means O type is the universal plasma recipient and AB type is the universal plasma donor.

Impella device use without Heparin

Most heart assist devices requires Heparin. Here is an interesting case report.

*Impella Video as an addendum after reference

"A 58-year-old Asian man with no history of cardiac disease, hypertension, or diabetes mellitus had an AMI and subsequent cardiogenic shock. He was started on dopamine and norepinephrine and transferred to a tertiary care center for rescue percutaneous coronary intervention (PCI). Given that his artery was patent with Thrombolysis In Myocardial Infarction 3 flow, PCI was not attempted. He had an ejection fraction of 25% and mid-distal anteroseptal akinesis. He was transferred to the intensive care unit on intra-aortic balloon pump (IABP) support. The patient’s condition continued to deteriorate, and an Impella LP 2.5 pVAD was inserted for additional hemodynamic support and as a bridge to definitive revascularization. To reduce the potential for medication error and decrease the patient’s bleeding risk, the purge solution was changed to 20% dextrose injection without heparin and continued at a rate of 15 mL/hr. The patient’s hemodynamic values improved, and the pVAD and IABP were continued for the next five days. The patient was successfully anticoagulated with i.v. heparin throughout the remainder of pVAD support. While the patient did develop hemolytic anemia during his device support, there were no thrombotic or bleeding complications."

Reference:

Douglas L. Jennings, Carrie W. Nemerovski and Akshay Khandelwal - Extended use of a percutaneous left-ventricular assist device without a heparin-based purge solution,  American Journal of Health-System Pharmacy November 1, 2010 vol. 67 no. 21 1825-1828