Factors related to cough strength before tracheal extubation in post-cardiac surgery patients: A cross-sectional study.

Background: Tracheal extubation failure after cardiac surgery is associated with diminished cough strength, albeit the information on cough strength in post-cardiac surgery patients is limited.
Aim: To investigate the cough strength in patients after cardiac surgery before tracheal extubation and the related influencing factors.
Study Design: A cross-sectional study was designed, with adherence to the STROBE guidelines. The participants were 528 patients undergoing open-heart cardiac surgery who were admitted to the Cardio Surgical Centre in a tertiary hospital in Nanjing, China, from August 2022 to September 2023. Cough peak flow (CPF) ≤60 L/min set as the cut-off value for evaluating diminished cough strength before tracheal extubation. Univariate analysis and multiple linear regression analysis were used to analyse the related influencing factors.
Results: The mean CPF was 130.70 ± 50.58 L/min. A total of 76 (14.4%) patients exhibited a CPF of ≤60 L/min. Multiple linear regression analysis revealed that gender (B = 14.266, t = 2.456, p = .014), inspiratory capacity (IC) (B = 0.013, t = 3.755, p < .001), preoperative CPF (B = 0.086, t = 3.903, p < .001), muscle strength (B = 12.423, t = 4.242, p < .001), preoperative exercise regimen (B = 16.716, t = 4.236, p < .001) and pain levels (B = -8.115, t = -5.794, p < .001) significantly contributed to cough strength.
Conclusions: Female gender, lower upper limb muscle strength, higher pain levels, lower preoperative CPF and IC, and the absence of systematic exercise were found to be associated with diminished cough strength.
Relevance to Clinical Practice: Cough strength provides important auxiliary data in extubation decision-making. In addition, understanding its relevant factors can help identify the high-risk group of tracheal extubation failure and can help provide a strong theoretical basis for the development of personalized interventions.
(© 2025 British Association of Critical Care Nurses.)