Routine Use of NG Tubes. Who needs an NGTube? When can we pull them out in non-obstructed patients? Cochrane has compiled the results of 37 randomized studies comparing routine NGT use to none (or immediate post-operative removal) in over 5700 patients undergoing open abdominal surgery of any type (gyn, emergency, onc, upper GI, lower GI, etc). The results strongly suggest that NGTs, used 'prophylactically' cause, or at least worsen, ileus. Patients without routine tubes had less ileus (p<0.00001!), less pulmonary complication (p=0.01) and shorter length of stay. There was no significant difference in any other outcome (leaks, hernias, or infections).
The bottom line is best summed up by the typically non-committal folks at Cochrane, "Routine nasogastric decompression does not accomplish any of its intended goals and so should be abandoned in favour of selective use of the nasogastric tube."
Verma R, Nelson RL. Prophylactic nasogastric decompression after abdominal surgery. Cochrane Database of Systematic Reviews 2007, Issue 3. Art. No.: CD004929
Troponin Leaks. Cardiac enzymes, troponins in particular, have become the gold standard for evaluating and establishing a diagnosis of Acute Coronary Syndrome. However, numerous studies have shown that troponins are elevated in some patients without any clinical signs or symptoms of acute coronary syndrome, prompting the recognition of the "troponin leak" phenomenon. Conditions associated with elevated troponins in the absence of ACS include (get ready, this list is LONG!): tachy- or bradyarrhythmias, or heart block, critically ill patients, especially with diabetes, respiratory failure or sepsis, hypertrophic cardiomyopathy, coronary vasospasm, acute neurological disease, including stroke or subarachnoid hemorrhage, cardiac contusion or other trauma including surgery, ablation, pacing, implantable cardioverter-defibrillator shocks, cardioversion, endomyocardial biopsy, cardiac surgery, following interventional closure of atrial septal defects, rhabdomyolysis with cardiac injury, congestive heart failure-acute and chronic, pulmonary embolism, severe pulmonary hypertension, renal failure, aortic dissection, aortic valve disease, apical ballooning syndrome – Takotsubo, cardiomyopathy, infiltrative diseases (ie, amyloidosis, hemochromatosis, sarcoidosis, and scleroderma), inflammatory diseases (ie, myocarditis or myocardial extension of endo-/pericarditis, Kawasaki disease), drug toxicity or toxins (ie, adriamycin, 5-flurouracil, herceptin, snake venom), burns, especially if affecting >25 percent of body surface area, extreme exertion, transplant vasculopathy.
One rather common condition encountered in the ICU setting associated with troponin leak is sepsis or SIRS. It is thought that these conditions cause the release of myocardial depressive factors that induce the degradation of troponin into low molecular weight particles. Sepsis also increases membrane permeability, allowing these troponin particulars to be released into the circulation for detection on assays. Increased myocardial oxygen demand coupled with decreased oxygen supply in sepsis or SIRS likely contributes to the troponin leak in these patients as well.
In a particularly eloquent study, Ammann et al. studied 20 patients with either SIRS, sepsis, or septic shock. They found that 17 out of the 20 patients had elevated troponins. Interestingly, coronary angiography, autopsy, and stress echo demonstrated that 10 of the 17 did not have significant coronary artery disease. It will be interesting to see whether future studies will address whether cardiac interventions could improve outcomes in these patients.
Ammann, P, Fehr, T, Minder, EI, et al. Elevation of troponin I in sepsis and septic shock. Intensive Care Med 2001; 27:965.
UptoDate.org - article entitled "Elevated Cardiac Troponin Concentration in the Absence of an Acute Coronary Syndrome"
Delirium: Pharmaceutical Prevention. Delirium affects patients' consciousness and increases the morbidity and mortality of ICU patients. Patients are at increased risk of self-extubation if ventilated, staying longer in the hospital, and subsequently suffering from more hospitalized infections, etc. This increases the healthcare costs. Pharmaceutical management of delirium has primarily focused on treatment and not prevention.
The MIND trial was a double blind, randomized, placebo controlled trial that assessed whether scheduled antipsychotics would improve the number of days alive without coma and delirium in 6 tertiary MICU/SICUs across the country. The randomized 101 mechanically ventilated patients to receive scheduled haloperidol, ziprasidone or placebo q6h. Outcomes measured included number of days alive without delirium or coma, ventilator free days, length of hospital stay, and mortality. Study concluded that there was no significant difference between the three trial groups regarding outcomes or safety profile.
By contrast, another double blind, prospective randomized placebo controlled pilot trial (mentioned previously in the rounds report) assessed whether scheduled quetiapine (q12h) in addition to as needed haloperidol would reduce length of stay, length of delirious episode, agitation, mortality, need for prn haloperidol in critically ill patients. This trial found that scheduled quetiapine was associated with faster resolution of delirium, less agitation, and fewer doses of prn haloperidol. There was no significant reduction in length of stay or mortality. Between the two groups there was no difference in incidence of QT prolongation or extrapyramidal signs. However, quetiapine was associated with increased somnolence. Thus the debate continues regarding the benefit of scheduled anti-psychotics. Additional studies to assess safety and efficacy are needed.
Girard, et. al. 2010. "Feasibility, efficacy, and safety of antipsychotics for intensive care unit delirium: The MIND randomized, placebo-controlled trial." Crit. Care. Med. 38(2):428-438.
Delvin, et. al. 2010. "Efficacy and safety of quetiapine in critically ill patients with delirium: A prospective, multicenter, randomized, double-blind, placebo-controlled pilot study." Crit. Care. Med. 38(2): 419-418.
Need more Rounds Reports? Old Issues are archived at UVARounds.blogspot.com
Jordan Hackworth, M.D.
Fellow, Critical Care Medicine
Department of Anesthesiology
University of Virginia
Department of Anesthesiology
University of Virginia