RESUMO
BACKGROUND: Cough impairment is often described as part of the pathophysiological basis of postoperative pulmonary complications (PPCs). However, there have been few studies examining cough effectiveness and its relationship with PPCs following open upper abdominal surgery. The goal of this study was to estimate (1) changes in cough efficacy after upper abdominal surgery through the assessment of peak cough flow and (2) the extent to which cough impairment is associated with postoperative pain, FVC, and risk of PPCs. METHODS: This prospective cohort study assessed 101 subjects (45% male, 56 ± 16 y old) admitted for elective upper abdominal surgery. Measurements of peak cough flow and FVC were performed on the day before surgery and repeated on postoperative days 1, 3, and 5. PPCs were assessed daily by a pulmonologist blinded to the cough measurement results. RESULTS: Peak cough flow dropped to 54% of the preoperative value on postoperative day 1 and gradually increased on postoperative days 3 (65%) and 5 (72%) (P < .05). On all postoperative days, peak cough flow was strongly correlated with FVC (P < .001) and weakly correlated with pain (P = .006). Six subjects (6%) developed PPCs. The association between peak cough flow and risk of PPCs was not statistically significant (unadjusted odds ratio of 0.80, 95% CI 0.45-1.40, P = .44; adjusted odds ratio of 0.66, 95% CI 0.32-1.38, P = .41). CONCLUSIONS: Cough effectiveness is impaired after upper abdominal surgery. Postoperative restrictive lung dysfunction seems to be associated with this impairment. There is no significant association between peak cough flow and PPCs; however, cough impairment might result in clinically important consequences in a high-risk population.
