Awareness With Paralysis in Mechanically Ventilated Patients in the Emergency Department and ICU: A Systematic Review and Meta-Analysis*

Abstract

OBJECTIVE: Awareness with paralysis is a devastating complication for mechanically ventilated patients and can carry long-term psychologic sequelae. Hundreds of thousands of patients require mechanical ventilation in the emergency department and ICU annually, yet awareness has only been rigorously examined in the operating room (incidence ~0.1%). This report collates the global literature regarding the incidence of awareness with paralysis outside of the operating room. DATA SOURCES: We searched OvidMedline, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, ClinicalTrials.gov, conference proceedings, and reference lists. STUDY SELECTION: Randomized or nonrandomized studies (except single case studies) reporting on awareness with paralysis in the emergency department or ICU were eligible. DATA EXTRACTION: Two independent reviewers screened abstracts for eligibility. DATA SYNTHESIS: The search identified 4,454 potentially eligible studies. Seven studies (n = 941 patients) were included for analysis. A random effects meta-analysis of proportions along with multiple subgroup analyses was performed. Significant between-study heterogeneity in reporting of awareness with paralysis was noted, and the quality of the evidence was low. Analyses stratified by: 1) good-quality studies and 2) use of the modified Brice questionnaire to detect awareness revealed estimates of 3.4% (95% CI, 0–10.2%) and 1.9% (95% CI, 1.0–3.0%), respectively. CONCLUSIONS: The incidence of awareness with paralysis in mechanically ventilated patients in the emergency department and ICU, as evaluated in a small number of qualifying studies from this comprehensive systematic review, appears much higher than that reported from the operating room. Given the clinical and statistical heterogeneity, caution is warranted in the interpretation of these findings. Further high-quality studies are needed to both define the true incidence and to target the prevention of awareness with paralysis in this vulnerable patient cohort.

Awareness With Paralysis Among Critically Ill Emergency Department Patients: A Prospective Cohort Study*

“…In addition, given the variability in lengths of stay and ventilator duration experienced by mechanically ventilated patients, the exact timing of questionnaire administration was not standardized, which could impact reproducibility. However, our event rate for AWP is consistent with prior work, lending face validity to the results (22, 62). In addition, the Brice questionnaire has not been extensively used outside of the operating room setting, and its sensitivity may vary among the critically ill. Our consistent results with prior work, rigorous adjudication methodology, and use of the ICU Memory Tool to attempt to separate memories from AWP events lend confidence in the results.…”

“…The first significant finding is that the proportion of patients experiencing AWP was 3.4%; when restricted to survivors, this proportion was 3.9%. This rate is similar to that observed from the ED-AWARENESS study, as well as a comprehensive systematic review and meta-analysis regarding AWP in mechanically ventilated patients in the ED and ICU (22, 62). Patient testimonials reflect vivid recollections of pain from procedures, being restrained, and feelings of impending death.…”

The AIR-SED Study: A Multicenter Cohort Study of SEDation Practices, Deep Sedation, and Coma Among Mechanically Ventilated AIR Transport Patients

“…Longer-acting neuromuscular blockers were also independently associated with deep sedation, and rocuronium use increased during the study period. Considering that these findings remained robust to sensitivity analyses, and similar analgesic and sedation doses existed between groups, this suggests that potentially paralyzed patients were being assessed as deeply sedated or comatose, with potential for underlying awareness with paralysis ( 19 , 20 ). This further stresses the importance of goal-oriented sedation, with clinical monitoring of sedation depth.…”

“…Given results of the primary multivariable model that showed that longer-acting neuromuscular blockers were associated with deep sedation, an exploratory post hoc sensitivity analysis was conducted, which adjusted for the total dose of analgesics and sedatives received. This was done to explore the possibility that patients receiving longer-acting neuromuscular blockers may receive higher sedative doses to prevent awareness with paralysis, leading to more deep sedation (i.e., in the causal pathway) ( 19 , 20 ). Given the imbalance that was demonstrated with respect to indication for mechanical ventilation, a second post hoc sensitivity analysis was conducted, which adjusted for this covariate.…”

The Feasibility of Implementing Targeted SEDation in Mechanically Ventilated Emergency Department Patients: The ED-SED Pilot Trial

“…The fact that no patients in the intervention group required reintubation is congruent with prior work from the ICU, demonstrating that lighter sedation does not lead to higher reintubation rates (4). Similarly, the incidence of awareness with paralysis was similar to prior work on mechanically ventilated patients in the ED and ICU (27,31). These data suggest that targeted sedation in the ED can be safely employed without increasing the safety events that could be related to a lighter sedation approach.…”