Breathlessness assessment, management and impact in the intensive care unit: a rapid review and narrative synthesis.

Background: Adults in the intensive care unit (ICU) commonly experience distressing symptoms and other concerns such as pain, delirium, and breathlessness. Breathlessness management is not supported by any ICU guidelines, unlike other symptoms.

Aim: To review the literature relating to (i) prevalence, intensity, assessment, and management of breathlessness in critically ill adults in the ICU receiving invasive and non-invasive mechanical ventilation (NIV) and high-flow oxygen therapy, (HFOT), (ii) the impact of breathlessness on ICU patients with regard to engagement with rehabilitation.

Methods: A rapid review and narrative synthesis using the Cochrane Methods Group Recommendations was conducted and reported in accordance with PRISMA. All study designs investigating breathlessness in adult ICU patients receiving either invasive mechanical ventilation (IMV), NIV or HFOT were eligible. PubMed, MEDLINE, The Cochrane Library and CINAHL databased were searched from June 2013 to June 2023. Studies were quality appraised.

Results: 19 studies representing 2822 ICU patients were included (participants mean age 48 years to 71 years; proportion of males 43-100%). The weighted mean prevalence of breathlessness in ICU patients receiving IMV was 49% (range 34-66%). The proportion of patients receiving NIV self-reporting moderate to severe dyspnoea was 55% prior to initiation. Breathlessness assessment tools included visual analogue scale, (VAS), numerical rating scale, (NRS) and modified BORG scale, (mBORG). In patients receiving NIV the highest reported median (interquartile range [IQR]) VAS, NRS and mBORG scores were 6.2cm (0-10 cm), 5 (2-7) and 6 (2.3-7) respectively (moderate to severe breathlessness). In patients receiving either NIV or HFOT the highest reported median (IQR) VAS, NRS and mBORG scores were 3 cm (0-6 cm), 8 (5-10) and 4 (3-5) respectively.

Conclusion: Breathlessness in adults receiving IMV, NIV or HFOT in the ICU is prevalent and clinically important with median intensity ratings indicating the presence of moderate to severe symptoms.