Early use of noninvasive bundle techniques for clearing respiratory secretions during noninvasive ventilation in hypercapnic encephalopathy

Abstract

Objective To examine the safety and effectiveness of early use of noninvasive techniques for clearing respiratory secretions during noninvasive ventilation (NIV) in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD) and hypercapnic encephalopathy. Methods This prospective cohort study was performed between October 2014 and October 2016 in intensive care unit (ICU). All included participants with hypercapnic encephalopathy in the ICU were randomly divided into two groups, NIV and invasive mechanism ventilation (IMV). Participants were managed using NIV, with airway management and clearance of secretions performed in the initial 2 hours of NIV, including repeated suctioning of secretions from an oropharyngeal airway (OPA), appropriate patient posture, nebulized inhalation of salbutamol and ambroxol and close monitoring, could be used to maintain a clear airway during the first two hours of NIV.Participants who received IMV were carried out after admission to the ICU without NIV being first attempted.The primary endpoints were: the safety (need for urgent ETI) and effectiveness (changes in ABGs and KMS) of the secretion clearing strategy within the first 2 hours of NIV, and the rate of major complications, especially septic complications and nosocomial pneumonia (including pulmonary aspiration) that were diagnosed using strict criteria. Results Of 186 patients with AECOPD screened for inclusion in the study, 164 were included in the analysis (90 in the IMV group and 74 in the NIV group). There were no significant differences between the two groups in any of the baseline characteristics.Compared to baseline, the ABGs improved significantly in both groups after 2 hours of mechanical ventilation, but no significant differences were observed in pH, partial pressure of oxygen/fraction of inspired oxygen and partial pressure of carbon dioxide between the NIV and IMV groups within the initial 2-hour period (F=24.35, 113.81, 238.14, all P>0.05). The sensorium level significantly improved within 2 hours in the NIV group (t=5.32, P<0.001), but was not evaluated in the IMV group due to the use of sedation.Subjects receiving IMV had a higher complication rate than those receiving NIV due to a greater occurrence of nosocomial infections and use of more invasive devices.There were no differences between the two groups in the overall duration of mechanical ventilation and the length of hospital stay.However, Kaplan-Meier analysis showed that the percentage of subjects not weaned from mechanical ventilation within 30 days was significantly lower in the NIV group than in the IMV group (log rank test, P=0.002). Conclusions The use of an OPA and suction aspiration, in combination with appropriate positioning of the patient and nebulized inhalation of salbutamol/ambroxol, was a feasible, simple, safe and effective method for clearing respiratory secretions in patients with AECOPD and hypercapnic encephalopathy. Key words: Chronic obstructive pulmonary disease; Hypercapnic encephalopathy; Noninvasive ventilation