Journal Article Annotations
2025, 2nd Quarter

Critical Care

Annotations by Natalie Fedotova, MD, PhD
July, 2025

Dyspnea Among Mechanically Ventilated Patients: A Systematic Review.

PUBLICATION #1 — Critical Care

Dyspnea Among Mechanically Ventilated Patients: A Systematic Review.

Kira A Grush, Ellie Svoboda, Peter J Dunbar, Arun Kannappan, Jenna Perrodin, Michael Z Root, Mark E Mikkelsen.

Abstract: Crit Care Med. 2025 Jun 1;53(6):e1282-e1291. doi: 10.1097/CCM.0000000000006664. Epub 2025 Apr 14.

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.

Keywords:
critical care; dyspnea; mechanical ventilation; prevalence; systematic review.

Annotation

The finding:
In this systematic review of prospective observational studies and randomized controlled trials (RCTs), dyspnea was reported in over 40% of communicative mechanically ventilated (MV) adult patients and was more likely to be described as “air hunger”. On average, dyspnea was moderate to severe and varied in intensity and prevalence based on the scale used and the time of evaluation, with increases over the course of SBTs. Dyspnea was associated with anxiety, pain, depression, and higher likelihood of PTSD. Several strategies were suggested to reduce dyspnea in communicative and non-communicative MV patients, from optimization of ventilator settings to fan and music therapy.

Strength and weaknesses:
This systematic review included several recent studies and new data from corresponding authors. On the other hand, characterization of prevalence and severity of dyspnea excluded retrospective studies and non-communicative patients, whose distress is more likely to be underestimated. In addition, the authors did not discuss the quality of evidence for various interventions.

Relevance:
This review adds to the growing recognition that significant dyspnea in MV patients is common and underestimated, despite its association with extreme suffering and delays in progression of care, such as MV weaning. The combination of fear of death linked to breathlessness and the experience of helplessness, exacerbated by barriers to communication, creates the conditions for traumatization. CL psychiatrists are uniquely situated to advocate for consistent assessment and management of dyspnea and associated psychiatric symptoms in the ICU and beyond. Further work is needed to develop clinical guidelines and effective evidence-based interventions, though promising directions exist. See Sher et al (2024, PMID: 37952697) for an excellent review of dyspnea and dyspnea-related anxiety in the ICU and Demoule et al (2024, PMID: 38388984) for a relatively recent statement endorsed by the European Respiratory Society and the European Society of Intensive Care Medicine.