Dyspnea Among Mechanically Ventilated Patients: A Systematic Review

OBJECTIVES:Dyspnea is a common and distressing symptom; yet, how frequently and intensely mechanically ventilated patients experience dyspnea remains unclear. We performed a systematic review to identify the prevalence and severity of dyspnea in communicative, mechanically ventilated critically ill adults. We also identified factors associated with dyspnea in the short-term and long-term and potential management strategies.DATA SOURCES:We performed a systematic search of the following databases: MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science Core Collection, PsycInfo, and CINAHL.DATA EXTRACTION:Our search strategy used variations of these terms: dyspnea, mechanical ventilation, and critical care. We included prospective observational studies and randomized controlled trials. Two independent reviewers screened citations and extracted data using a predrafted report form to examine dyspnea prevalence and severity, association with short-term and long-term outcomes, and interventions to mitigate dyspnea.DATA SYNTHESIS:Of 6290 records screened, we included 21 observational studies and 3 randomized controlled trials. We calculated percentages and 95% CIs for prevalence using Stata 17 se. Dyspnea was present in 475 of 1169 communicative, mechanically ventilated patients (40.6%, 95% CI, 37.8-43.5) and was found to be moderate to severe. In the lone study to examine long-term outcomes, dyspnea was associated with posttraumatic stress disorder (PTSD) at 90 days. Interventions to reduce dyspnea included: mechanical threshold inspiratory muscle training, ventilation adjustments, supplemental high-flow nasal cannula, opioids, hyperoxemia, and nonpharmacologic interventions, including music and fan therapy.CONCLUSIONS:In this systematic review, we found that dyspnea among mechanically ventilated patients is common and moderate to severe in its intensity. Dyspnea is associated with adverse long-term outcomes, including probable PTSD. Strategies to manage, or palliate, dyspnea were identified. Future study is warranted to examine how this information can be incorporated into clinical practice to improve short-term and long-term outcomes.