Objectives: To determine whether cough strength is associated with extubation outcomes and to determine the minimum cough strength which best predicts extubation outcomes in patients who have successfully completed weaning.
Study Design: Prospective cohort study
Study Setting and Time Period: Mechanically ventilated patients admitted to MICU, SICU, RR, CCU and SICU of the Philippine Heart Center from January 1, 2003 to September 30, 2003.
Measurements and Results: Mechanically ventilated patients were first assessed if they were qualified to undergo weaning from the mechanical ventilator. After completing a two-hour weaning, just prior to extubation, cough strength was measured using a Wright's Spirometer. Patients who remained extubated after 72 hours were classified as being successfully extubated. The cough strength of those who were successfully extubated were significantly higher than of those who failed extubation (0.074 ± 0.343 vs 0.612 ± 0.466 L/sec, respectively: p value = 0.022). A cough strength of 0.35 L/sec demarcates extubtion successes and failures (sensitivity = 61.54, specificity = 93.44, positive predictive value = 66.67, negative predictive value = 94, OR = 22.80, 95% CI 4.16, 142.78, p = 0.0000)
Conclusion: Cough strength positively predicts extubation outcomes in patients who have been successfully weaned. A cough strength, 0.35 L/sec demarcates between extubation successes and failures.