Some Recent Controversies in Intensive Care

Abstract

The ability of dopamine to reverse oliguria has led to its ubiquitous renal protective use in patients at risk of acute renal failure. However, this diuresis is due primarily to inhibition of distal tubular sodium reabsorption and not renal vasodilation. Recent controlled clinical studies have been unable to demonstrate a renal protective effect independent of changes in cardiac output. Selective decontamination of the digestive tract (SDD) has the appealing theoretical ability to minimize upper gastrointestinal colonization with gram-negative bacteria and fungi, and subsequently reduce nosocomial infection and mortality. Such modification of flora does occur, but the initial studies showing a reduction in lower respiratory tract infections have not been supported by recent large double-blind randomized controlled trials. A reduction in mortality or length of stay of general intensive care patients given SDD has never been demonstrated, and it remains an experimental therapy with possible application for some patient subgroups. Upper gastrointestinal hemorrhage (UGH) in the critically ill is associated with prolonged ventilatory support and coagulopathy, but clinically important bleeding is now uncommon. Prophylaxis with agents that increase gastric pH is effective in reducing UGH, but may be associated with a higher incidence of nosocomial pneumonia than occurs with alternatives such as sucralfate. Prophylaxis does not alter mortality, and it is now controversial which patients, if any, should routinely receive such treatment.