Are We Causing PTSD with Our Current Sedation Practices?
Abstract & Commentary
By Andrew M. Luks, MD, Pulmonary and Critical Care Medicine, University of Washington, Seattle, is Associate Editor for Critical Care Alert.
Dr. Luks reports no financial relationship to this field of study.
Synopsis: This randomized, single-center study demonstrated that light-sedation strategies in a mixed surgical and medical ICU population are associated with decreased ICU length of stay and duration of mechanical ventilation without adverse effects on patient safety or mental well-being.
Source: Treggiari MM, et al. Randomized trial of light versus deep sedation on mental health after critical illness. Crit Care Med 2009 Jul 13; Epub ahead of print.
After randomized controlled trials demonstrated the benefit of daily sedation and analgesia vacations in critically ill patients,1,2 sedation and analgesia practices in many centers changed, such that patients are now maintained at a lighter depth of sedation. The effect of such practices on the mental health of patients who survive their ICU stay remains unclear, however. Treggiari and colleagues investigated this question further by testing the hypothesis that light sedation would result in fewer adverse mental health outcomes in patients following an ICU stay.
They conducted a randomized controlled trial in the medical and surgical ICUs at a single, tertiary medical center. Patients were eligible for inclusion if they were > 16 years of age, intubated, and expected to require mechanical ventilation for > 12 hours, but were excluded if they had a primary neurologic condition (e.g., cerebrovascular accident, traumatic brain injury) with expected best discharge Glasgow Coma score < 8, neuromuscular disease requiring ventilatory support, chronic renal insufficiency, allergy to benzodiazepines or morphine, or met several other exclusion criteria. Eligible patients were randomized to a midazolam-based sedation strategy targeting either a cooperative, interactive state (light sedation, Ramsay level 1-2) or a more heavily sedated state (deep sedation, Ramsay level 3-4). Equal levels of pain relief were targeted using morphine-based analgesia in the two groups. Patients were weaned from the ventilator using standardized protocols and sedative administration was stopped when patients met criteria for initiation of unassisted breathing.
The primary study endpoints were post-traumatic stress disorder (PTSD), depression, and anxiety scores reported by patients on standardized assessment tools completed 4 weeks following ICU discharge. Secondary endpoints included ICU length of stay, duration of mechanical ventilation, severity of organ failure, hospital length of stay, and mortality. Because of obvious differences in the state of arousal in the two groups, a double-blind protocol was not feasible, although the outcome assessments were performed in a blind manner. The data were analyzed using an intention-to-treat approach.
At 4-week follow-up, patients in the deep sedation group (n = 64) tended to have higher PTSD scores than those receiving light sedation (n = 65), although this difference was not statistically significant and similar proportions of the two groups met diagnostic criteria for PTSD (10% vs 9%). There were also no differences in anxiety and depression scores between the two groups at 4-week follow-up. Patients receiving deeper sedation did, however, have more trouble remembering the event (37% vs 14%) and more disturbing memories of their ICU stay (18% vs 4%) than the light-sedation group, with both differences reaching statistical significance. Regarding the secondary outcomes, patients managed with lighter sedation had a statistically significantly shorter duration of mechanical ventilation (2.9 ± 5.0 vs 5.5 ± 10.8 days; P < 0.02) and ICU length of stay (4.0 days, range 1-129 days, vs 5.5 days, range of 2-99 days; P < 0.03) with no difference in the incidence of agitation, soft physical restraint use, unplanned extubation, tachycardia, or hypertension.
Commentary
Treggiari and colleagues hypothesized that lighter sedation would be associated with less PTSD and other psychiatric illness following ICU discharge. Although these outcomes were not realized and this is essentially a negative study, there is still considerable value in these results.
Daily interruption of sedative and analgesic drips has been shown in randomized controlled studies to reduce the duration of mechanical ventilation and ICU length of stay. While these two important outcomes significantly decrease the risk of complications for critically ill patients, these results, and daily sedation vacations, in general, might be viewed in less favorable light if it turned out that patients were having more significant psychiatric problems following discharge because they were maintained on lighter sedation and had too much recall of their ICU stay and its associated events. The fact that the incidence of PTSD, depression, and anxiety were similar between the deep- and light-sedation groups in the current study tells us that shorter duration of mechanical ventilation and ICU length of stay can be achieved using sedation protocols targeting lower Ramsay scores without causing more psychiatric illness or other adverse outcomes. In essence, when it comes to sedation protocols emphasizing lighter sedation, we can have our cake and eat it too.
Among some of the other adverse outcomes investigated in this study, it was interesting that there were no differences in the incidence of self-extubation, as one might expect lightly sedated patients to reach for their endotracheal tubes or other invasive lines and, therefore, require the use of restraints and other tactics that often only serve to worsen patient agitation. In line with findings from the first trial of daily sedation vacations,1 the above results demonstrate that this expectation was not borne out.
A key question that follows from these results, however, is whether it will be possible to change practice and realize these benefits. We have solid randomized, controlled data demonstrating a benefit to lung-protective ventilation in ARDS, for example, but evidence suggests there have been significant barriers to implementing this strategy on a wide basis.3 Old habits often die hard and considerable education will be necessary to change the practice of deeply sedating patients that still persists in many hospitals.
References
- Kress JP, et al. Daily interruption of sedative infusions in critically ill patients undergoing mechanical ventilation. N Engl J Med 2000;342:1471-1477.
- Girard TD, et al. Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (Awakening and Breathing Controlled trial): A randomized controlled trial. Lancet 2008;371:126-134.
- Rubenfeld GD, et al. Barriers to providing lung-protective ventilation to patients with acute lung injury. Crit Care Med 2004;32:1289-1293.
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