Effects of the domiciliary use of benzodiazepines on the management of patients presenting to the emergency department with exacerbations of chronic obstructive pulmonary disease

Introduction

The use of hypnotics for sleep disturbances has been discouraged for patients with severe chronic obstructive pulmonary disease (COPD), because of potential adverse effects on ventilation. We evaluated the clinical impaction of benzodiazepine use in patients presenting to the Emergency Department (ED) with acute exacerbation of COPD.

Methods

Of 317 consecutive patients presenting to the ED with acute dyspnoea from March to September 2004, 47 were found affected by exacerbations of COPD complicated by acute respiratory failure. Diagnosis was based on the 2004 COPD Guidelines of American Thoracic Society/European Respiratory Society. A thorough investigation (through the pharmacologic history collected from patient and/or caregivers and any available medical record) was made on each patient about the habitual use of hypnotics, particularly benzodiazepines, up until the day of admission. We evaluated mortality at discharge, need for and duration of invasive and noninvasive mechanical ventilation and hospital length of stay in patients taking benzodiazepines (BDZ+) in comparison with those who did not (BDZ-).

Results

Of 47 patients identified (28 males/19 females, mean age 74.7 years, APACHE II score 17.4 ± 5.3), 12 (25.5%) regularly used benzodiazepines for insomnia. Table 1 presents the APACHE II score, systolic blood pressure and arterial blood gas analysis of the BDZ- in comparison with the BDZ+.

Table 1

The mortality of BDZ+ was 16.6% versus 8.6% of BDZ- (χ²: P = 0.43); no patient was intubated, but 66% of BDZ+ underwent noninvasive ventilation versus 40% of BDZ- (χ²: P = 0.11). The duration of noninvasive ventilation was 23 hours 22 min for BDZ+ versus 14 hours 9 min for BDZ-: a statistically significant difference (χ²: P = 0.04). Hospital length of stay was 9 ± 5.5 for BDZ+ versus 15.2 ± 10.5 for the BDZ- group (χ²: P = 0.06).

Conclusions

In patients with exacerbations of COPD, domiciliary use of benzodiazepines had no effect on mortality and hospital length of stay, but seemed to cause a higher need for and increased duration of noninvasive ventilation.