Adaptive support ventilation versus biphasic positive airway pressure in patients with acute exacerbation of chronic obstructive pulmonary disease

Abstract

Introduction The goal of mechanical ventilation in acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is to maintain both adequate oxygenation and ventilation, reduce the work of breathing, and improve the comfort of the patient until the condition has been reversed or alleviated. Unlike conventional pressure-controlled ventilatory modes, biphasic modes [biphasic positive airway pressure (BIPAP)] allow for unrestricted spontaneous breathing. Adaptive support ventilation (ASV) is a new ventilatory mode that uses a closed-loop controlled mode between breaths. It can be used safely during initiation, maintenance, or weaning phases of the mechanical ventilation. Objective The aim of this work was to compare between BIPAP and ASV in the management of patients with AECOPD in terms of ventilatory parameters, lung mechanics, patient ventilator dys-synchrony, days of mechanical ventilation, and mortality. Patients and methods This double-blind randomized trial was conducted on 72 AECOPD adult patients admitted to the units of Critical Care Medicine Department in Alexandria Main University Hospital indicated for invasive mechanical ventilation. Patients were excluded for reasons such as pregnancy, hemodynamic instability, and severe neurological disease. They were categorized randomly as follows: group I included 36 patients who were ventilated using the BIPAP mode and group II included 36 patients who were ventilated using the ASV mode. Informed consent was obtained from patients' first of kin after approval from the Ethical Committee of Alexandria Faculty of Medicine. Ventilatory parameters (respiratory rate, tidal volume, peak airway pressure, and rapid shallow breathing index) and lung mechanics (static compliance and inspiratory resistance) were recorded. Patient ventilator dys-synchrony and asynchrony index were recorded daily. Days of mechanical ventilation, ICU stay, and mortality were calculated. Results In the ASV group, the respiratory rate was significantly lower, tidal volume was higher, and rapid shallow breathing index was lower. Significantly higher compliance and lower resistance were encountered in the ASV group, with better patient-ventilator synchronization. A significant reduction in days of mechanical ventilation in the ASV group was found with less ICU length of stay. Conclusion ASV may be safer in AECOPD patients and may have a better prognosis.