Nutrition intake, muscle thickness, and recovery outcomes for critically ill patients requiring non-invasive forms of respiratory support: A prospective observational study

Background: Use of high-flow nasal cannula (HFNC) and non-invasive ventilation (NIV) in the intensive care unit (ICU) is increasing, yet reporting of nutrition intake, muscle thickness, or recovery outcomes in this population is limited. Objective: The objective of this study was to quantify muscle thickness, nutrition intake, and functional recovery outcomes for patients receiving HFNC/NIV within the ICU. Methods: A single-centre, prospective, observational study in adult ICU patients recruited within 48 hrs of commencing HFNC/NIV. Change in quadriceps muscle layer thickness using ultrasound (primary outcome) and 24 hr nutrition intake from study inclusion to day 7 (D7), functional capacity (Barthel Index), and quality of life (EuroQol five-dimension five-level utility index) at D90 were assessed. Data are n (%), mean ± standard deviation or median [interquartile range], are compared using paired sample t-test, and a P value of <0.05 was considered significant. Results: Primary outcome data were available for n = 28/42: 64 ± 13 y, 61% male, body mass index: 29.1 ± 9.0 kg/m², and Acute Physiology and Chronic Health Evaluation II score: 17 ± 5. Quadriceps muscle layer thickness reduced from 2.41 ± 0.87 to 2.12 ± 0.73 cm; mean difference: −0.29 cm (95% confidence interval: -0.44, −0.13). Nutrition intake increased from study inclusion to D7: 1735 ± 1283 to 5448 ± 2858 kJ and 17.4 ± 16.6 to 60.9 ± 36.8g protein. Barthel Index was 87 ± 20 at baseline and 91 ± 15 at D90 (out of 100). Quality of life was impaired at D90: 0.64 ± 0.23 (health = 1.0). Conclusion: Critically ill patients receiving HFNC/NIV experienced muscle loss and impaired quality of life.