By taking mechanically ventilated patients in intensive care off of tranquilizing medications for a short time each day, researchers at the University of Chicago Hospitals were able to reduce the duration of ventilation and cut ICU stays by one-third. Brief daily awakenings also allowed physicians to perform more thorough physical exams, lowered drug requirements, and reduced the need for diagnostic tests related to mental status.
Since nearly one percent of the United States' gross national product more than $80 billion in 1997 is spent on ICU care, this simple change could not only hasten recovery for many ICU patients but could significantly lower health care costs.
The finding is reported in the May 18th issue of the New England Journal of Medicine.
"Patients who require intensive care and mechanical ventilation are at high risk for developing complications related to their illness and its treatment," said lead author John P Kress, M.D., instructor of medicine at the University of Chicago. "Time on the ventilator increases the risks of infection, bleeding or clotting. Anything we can do to free patients from dependence on this technology is a step forward."
"Now we have a simple, practical, cost-effective intervention that can be readily performed by the bedside nurse," added senior author Jesse Hall, M.D., professor of medicine and section chief of pulmonology and critical care medicine at the University of Chicago. "It speeds recovery and saves money. It may also improve outcomes."
Patients who require mechanical ventilation are commonly given a continuous infusion of sedatives to reduce their anxiety, prevent agitation, decrease oxygen needs and facilitate nursing care. Continuous infusion of these drugs has become standard practice because it maintains consistent levels of sedation and improves patient comfort.
One drawback, however, is that continuous infusion can lead to drug accumulation and delay re-awakening. Kress and colleagues suspected that a brief daily sedative interlude could prevent drug build-up and decrease related problems yet maintain patient comfort.
They performed a randomized, controlled trial involving 128 critically ill adult patients who required mechanical ventilation. Half of the patients received continuous infusions of sedatives, which were discontinued at the discretion of the ICU team.
The other half had their sedative and morphine infusions stopped each day until the patient either woke up enough to follow simple commands (such as "open your eyes," or "squeeze my hand") or began to show signs of agitation or discomfort. Patients who still needed sedatives were then restarted on continuous infusion, although they were often given a lower dose.
The 68 patients who had daily sedative breaks recovered much more quickly. They were able to breathe on their own 33 percent sooner, after a median of 4.9 days, compared to 7.3 days for those who did not have sedative breaks. They left the ICU 35 percent sooner, after a median of 6.4 days, compared to 9.9 days.
Patients who had their sedatives stopped daily were nearly ten times more likely to spend some portion of each day awake, which made assessment of mental status changes much easier. The 60 patients receiving continuous sedatives required 16 diagnostic tests related to mental status (13 brain CT scans, 2 brain MRI scans, one lumbar puncture), most of which were not helpful, compared to six brain CT scans in the 68 patients who had a daily sedative recess.
Although this study was too small to provide statistically convincing evidence, patients who had their sedatives interrupted did show a trend toward better outcomes, with ten percent fewer deaths, fewer patients sent to long-term ventilator facilities, and 59 percent of patients discharged to home, compared to only 40 percent of the patients given continuous sedatives. The average length of hospital stay was also shorter, 13.3 days compared to 16.9.
"For years the discussion has focused on measuring the tiny differences between different sedatives," explained Hall. This study, which also looked at two different types of sedatives, "made it clear," Hall said, that "it's not the drugs, it's how you use them."
The study found no short-term adverse effects caused by stopping sedatives briefly each day. The researchers hope to start a longer-term study soon to see if the daily break from sedation altered patients' perceptions or heightened memories of their ICU stay.
Many patients have no recall of their time in intensive care. Some may remember it as a disturbing time of confusion and uncertainty. "We suspect that periodic interaction with the medical staff and daily re-orienting with family members may decrease unpleasant memories of an ICU stay," said Kress.
Other researchers contributing to this study were Anne Pohlman, R.N./M.S.N., and Michael O'Connor, M.D.
Journal
New England Journal of Medicine