Invasive versus Non-invasive Positive Pressure Ventilation In Chronic Obstructive Pulmonary Disease Complicated By Acute Respiratory Failure

Abstract

Introduction Acute exacerbation of chronic obstructive pulmonary disease (AECOPD) is frequently encountered as a medical emergency. AECOPD is the third leading medical cause of hospitalization due to acute respiratory failure (ARF). The utilization of ventilators for patients with ARF secondary to AECOPD has increased. There has been a major inclination towards utilization of non-invasive positive pressure ventilation (NIPPV) and sparing invasive positive pressure ventilation (IPPV) for life-threatening respiratory distress and/or in patients where NIPPV failure is observed. The aim of this observational study was to compare the clinical and laboratory parameters patients with chronic obstructive pulmonary disease (COPD) complicated by ARF admitted in the intensive care unit (ICU). Methods In the prospective observational study with known cases of COPD complicated by ARF, patients were grouped into NIPPV and IPPV groups based on their clinical and laboratory parameters. Thirty patients were included in each group. Demographic data was collected. Clinical and laboratory parameters were evaluated at baseline and at 24 hours of ventilation. The outcome was assessed in terms of duration of ventilation, hospital and ICU stay and overall mortality. Data was entered and analyzed using SPSS version 22.0 (IBM Corp., Armonk, NY). Results Both IPPV and NIPPV groups demonstrated marked reduction in partial pressure of carbon dioxide (PaCO₂) with 24 hours of ventilation (for IPPV: 78.1 ± 20.2 vs. 69.1 ± 20.2; p=0.08) (for NIPPV: 68.1 ± 17.8 vs. 57.2 ± 21.5; p=0.03). In NIPPV group, there was significant improvement in partial pressure of oxygen (PaO₂) (p=0.009), respiratory rate (p=0.008), heart rate (p<0.0001), systolic blood pressure (p=0.03), and diastolic blood pressure (p<0.0001). These parameters did not improve significantly in the IPPV group except for systolic blood pressure (p=0.008). The NIPPV failure rate was 20%. NIPPV patients had a significantly shorter duration of ventilation, ICU stay, and hospital stay. In-ICU mortality was significantly lower in the NIPPV group as compared to IPPV (13% vs. 40%; p=0.01). There was no difference in post-ICU in-hospital mortality between the two groups (6.7% vs. 16.7%; p=0.13). Conclusion Both NIPPV and IPPV are effective in normalizing acidosis and hypercapnia in patients with COPD complicated by ARF. Patients managed with non-invasive mode of ventilation have a shorter duration of ICU as well as hospital stay. Survival rates are also better as compared to patients managed with invasive ventilation.

Keywords: acute exacerbation of copd; acute respiratory failure; blood gas analysis; chronic obstructive pulmonary disease; invasive ventilation; mechanical ventilation; mortality; noninvasive ventilation; survival.