Study the Efficacy of Using Non Invasive Positive Pressure Ventilation as a Prophylactic Modality against Post-Extubation Respiratory Failure in Patients with Cardiogenic Pulmonary Edema

Background: Post-extubation respiratory failure is a common event after discontinuation of mechanical ventilation. The incidence of reintubation is relatively high, being about 623% among patients undergoing, mechanical ventilation for more than 48 hours within 48-72 hours of endotracheal removal, so it is important to identify those patients at risk of post extubation respiratory failure. Aim of the Work: The present study aimed to assess the efficacy of early application of non invasive positive pressure ventilation in preventing post-extubation respiratory failure in patients with ACPE. Patients and Methods: The present study was done in Critical Care Medicine Department of Alexandria main University Hospital, it was carried out on 32 adult patients of both sexes who were presented with acute cardiogenic pulmonary edema, required mechanical ventilation with endotracheal intubation for a certain time duration till resolution of pulmonary edema, correction of potentially life threatening acid-base and blood gases abnormalities, stabilization of hemodynamic parameters and improvement of level of consciousness. Informed consent was taken from every patient included in the study or from one of his/her relatives. Demographic data, full medical history, complete clinical examination, arterial blood gases measurements, laboratory investigations, chest radiography, central venous pressure measurement, and 12 lead electrocardiography were done on admission of the studied patients. In addition to measurements of some weaning parameters before extubation to ensure successful weaning trial. Patients then were randomized into two groups: Group A (control group): This group included 16 patients who were disconnected from the ventilator; breathed spontaneously through a T-tube circuit for at least 2 hours, and supplied with humidified O2 ill arterial oxygen saturation equal to or above 90 % as measured by pulse oximetry was achieved. Group B (NIPPV group): This group included 16 patients who were disconnected from the ventilator; extubated, and immediately ventilated with non invasive positive pressure ventilation via oronasal mask. The pulse, respiratory rate, blood pressure, arterial blood gases, alveolar oxygen tension, shunt fraction, oxygen extraction ratio, and central venous pressure were measured for both groups every 4 hours for 48 hours with continuous electrocardiographic monitoring and the efficacy was recorded as the number of patients successfully weaned. Results: Weaning was considered successful if spontaneous breathing is sustained for more than 48 hrs after discontinuation of mechanical ventilation. There was statistically significant difference between the two studied groups as regards the mean pulse rate, mean respiratory rate, mean systolic and diastolic blood pressure through out the study. There was statistically significant difference between the two studied groups as regards the mean Pa02, mean alveolar oxygen tension, mean shunt fraction and mean central venous pressure throughout the study. There was no statistically significant difference between the two studied groups as regards the mean pH, mean PaCO2, mean serum HCO3, and mean oxygen extraction ratio throughout the study. There was no statistically significant difference between the two studied groups as regards the causes of weaning failure, weaning time, duration from extubation to reintubation, length of ICU stay, mortality rate, and incidence and types of complications throughout the study. There was statistically significant difference between the two studied groups as regards success of weaning as there were 15 patients successfully weaned in group B in comparison to 11 patients in group A. So, early application of noninvasive positive pressure mechanical ventilation in the present study was more efficient than the standard medical therapy to prevent post-extubation respiratory failure in the selected patients. [Hassan A. Othman, Tamer A. Helmy and Ayman Nasr Study the Efficacy of Using Non Invasive Positive Pressure Ventilation as a Prophylactic Modality against Post-Extubation Respiratory Failure in Patients with Cardiogenic Pulmonary Edema] Journal of American Science 2011; 7(11):300-315]. (ISSN: 1545-1003). http://www.americanscience.org.