Purpose: To study the effects of withdrawing noninvasive ventilation (NIV) used during acute exacerbation of chronic obstructive pulmonary disease for the delivery of aerosolized medications on physiologic parameters and dyspnea sensation.
Methods: We measured accessory muscle use, dyspnea sensation, heart rate (HR), respiratory rate (RR), blood pressure (BP), and arterial blood gases during NIV, 10 minutes after cessation of NIV (with oxygen), after nebulization with salbutamol (5 mg) and ipratropium (500 microg), and again, on restitution of NIV.
Results: We studied 19 patients (3 women; mean [+/-SD] age, 72 [+/- 9] years) with a mean postbronchodilator forced expiratory volume in 1 second 40% (+/-12) of predicted. Baseline RR (23/min), HR (98/min), BP (121/62 mm Hg), Spo(2) (95%), pH (7.31 [+/-0.06]), Paco(2) (65 [+/-12] mm Hg), and Borg score (1.8 [+/-0.43]) were recorded. There were no significant changes in physiologic parameters and oxygenation between NIV and nebulization periods. The only physiologic changes observed were increase in systolic BP (SBP, P = .012) and HR (P = .003) after nebulization. However, significant decrease in oxygen saturation (P = .009) and increase in SBP (P = nonsignificant) were observed between NIV and oxygenation phases.
Conclusion: Short-term cessation of NIV for nebulization treatment did not result in distress, discomfort, or physiologic instabilities. The only detectable changes were increase in SBP and HR, probably due to the systemic adrenergic effects of salbutamol.