The aim of sedation in critically-ill patients on mechanical ventilation in the intensive care unit (ICU) is to minimize oxygen consumption and facilitate a patient’s ability to remain comfortable on the ventilator. However, prolonged and deep sedation can increase the duration of mechanical ventilation, delay weaning, impair neuromuscular function, induce delirium, and cause poor functional status after discharge from the hospital.
A landmark study by Kress et al. revealed that the daily interruption of sedative infusions in patients on mechanical ventilation is safe and is associated with a decreased duration of mechanical ventilation and a shorter length of stay in ICU, as opposed to the control group, where infusions were interrupted only at the discretion of the clinicians [1].
The "Wake up and breathe" protocol, which paired spontaneous awakening trials (daily interruption of sedatives) with spontaneous breathing trials, was associated with a better outcome compared to standard approaches. Patients in the intervention group had more ventilator-free days and a shorter stay in the ICU and in the hospital [2]. Since then, this practice has been accommodated in many ICUs around the world and has become the standard of care.
The sedation algorithm (where sedatives are minimized for a RASS goal) was directly compared with the daily interruption of sedation (DIS) in a study by de Wit et al [3]. The study was stopped early by the monitoring board due to increased hospital mortality in the DIS group with no identifiable causal relationship. The sedation algorithm was associated with reduced duration of MV and lengths of stay compared to DIS.
More recently, a strategy of eliminating sedation was compared with light sedation and daily sedation breaks in a trial by Olson et al. The study involved 700 patients in eight centers to test the hypothesis that a 90-day mortality would be lower in the no-sedation group (as it was suggested in a prior single center trial). It was found that mortality at 90 days was not statistically different between the two groups (42% in the no-sedation group compared to 37% in the sedation group, relative risk, 1.10; 95% confidence interval, 0.90 to 1.35). None of the secondary outcomes (mechanical ventilation free days, length of stay in ICU, days free from coma or delirium, or accidental extubation) differed significantly between the trial groups. However, the number of thromboembolic events was higher in the sedation group compared to the no-sedation group.
The attached algorithm is a tool that can help the clinician to guide therapeutic interventions and minimize sedation and analgesia. Three main goals need to be achieved: CPOT (Critical Care Pain Observation Tool) of 0-1, RASS (Richmond Agitation Sedation Scale) of 0 to -1, and a negative CAM-ICU (Confusion Assessment Method for ICU). The clinician's objective is to achieve these goals with minimal or no analgesics or sedatives. Once achieved, the patient gets daily spontaneous awakening trials (daily interruption of sedatives) with spontaneous breathing trials and assessment for extubation.
REFERENCES
1. Kress, JP, Pohlman, AS, O’Connor, MF, Hall, JB. Daily interruption of sedative infusions in critically Ill patients undergoing mechanical ventilation. N Engl J Med. 2000;342(20):1471–1477. https://DOI:10.1056/NEJM200005183422002
2. Girard TD, Kress JP, Fuchs BD, Thomason JW, Schweickert WD, Pun BT, Taichman DB, Dunn JG, Pohlman AS, Kinniry PA, Jackson JC, Canonico AE, Light RW, Shintani AK, Thompson JL, Gordon SM, Hall JB, Dittus RS, Bernard GR, Ely EW: Efficacy and safety of a paired sedation and ventilator weaning protocol for mechanically ventilated patients in intensive care (awakening and breathing controlled trial): a randomised controlled trial. Lancet 2008, 371: 126-134. 10.1016/S0140-6736(08)60105-1
3. de Wit, M., Gennings, C., Jenvey, W.I. et al. Randomized trial comparing daily interruption of sedation and nursing-implemented sedation algorithm in medical intensive care unit patients. Crit Care 12, R70 (2008). https://doi.org/10.1186/cc6908
4. Olsen HT, Nedergaard HK, Strøm T, et al. Nonsedation or light sedation in critically ill, mechanically ventilated patients. N Engl J Med 2020;382:1103-1111.