PEAK COUGH FLOW AND RESPIRATORY MUSCLE STRENGTH IN SUCCESSFULLY EXTUBATED PATIENTS

PEAK COUGH FLOW AND RESPIRATORY MUSCLE STRENGTH

Abstract

Introduction: Peak Cough Flow (PCF) and Respiratory Muscle Strength (RMS) are essential in the functional assessment of critically ill patients as they predict the success of extubation. Objectives: To correlate PCF and RMS in successfully extubated patients admitted to an Intensive Care Unit (ICU). Methods: This was a cross-sectional study carried out in a university hospital ICU between May and October 2024. Adult patients extubated more than 48 hours ago and without cognitive deficits were included. PCF was assessed with a Peak Flow Meter, and MIP/MEP by manovacometry. Statistical analysis used Pearson's correlation coefficient, with results expressed as median and interquartile range, adopting p<0.05 as significance. Results: The sample included 20 patients, mostly men (55%), with a mean age of 63 years. The duration of MV ranged from 16 to 116 hours, and the median hospital stay was 9.5 days. The median PCF was 185 L/min, and most of the sample was below the predictive limit (160 L/min). MIP and MEP were also below the predictive value proposed by Neder. A significant negative correlation was observed between the duration of MV and PCF (r= -0.583), and a small correlation between MIP and MEP (r= 0.426). There was no statistically significant correlation between RMS and the length of hospital stay, duration of MV, or time after extubation. Conclusion: The findings suggest that post-extubated patients present a reduction in PFT and FMR, and a reduction in coughing the longer the MV time. MIP can influence the generation of an effective PFT, and there is a possible association between MIP and MEP.