Mortality of patients undergoing non-invasive mechanical ventilation

Abstract

Aim: The non invasive mechanical ventilation is considered the first choice of ventilation in patients with respiratory insufficiency secondary to exacerbated chronic pulmonary obstructive disease, acute pulmonary edema mechanical ventilation is the possibility to avoid intubation and invasive mechanical ventilation with its complications, less morbidity and mortality, and less hospital stay. Besides, it is more comfortable, the patient can communicate, eat and drink, cough, avoid the need of profound sedation, and maintain the defense mechanisms of superior airway. The main objective was to establish if the patients who received non invasive ventilation had a benefit in mortality statistically significant. It was also evaluated which were the most frequent pulmonary diseases, the type of respiratory insufficiency associated with the therapy, the type of interface used, the most frequent complications, and which of the pulmonary diseases benefited most in morbidity and mortality with the use of this type of ventilation.

Methods: We did a prospective, observational and case report study. Of a total population of 18 - 85 years hospitalized in a period between 1 of August and 31 of November of 2014, we studied a total of 40 patients who developed a respiratory disease who met the criteria to receive treatment with non invasive ventilation.

Results: The department who used more non invasive ventilation was the Intensive Care Unit. There were more male patients, with an average age of 55 years. The average time of therapy was 8,4 hours. The most frequent diagnostics where pneumoniae, acute pulmonary edema, and acute respiratory distress syndrome. For these diseases the hipoxemic respiratory insufficiency was the principal indication. The fullface was the main interface used. The complications of pressure ulcers and pneumoniae where infrequent during therapy. There were none shocked patients under therapy and tachycardia was the main risk factor of dying without being statistically significant. We didn't find gasometric changes neither changes in the respiratory index or alveolar-arterial gradient during therapy. The majority of patients with pneumonia and acute pulmonary edema started the therapy with a respiratory index less than 150, but this didn`t relate with more time in therapy neither more mortality. The scores of APACHE-II and SOFA where low at the beginning of the therapy, the observed mortality was of 12%.

Conclusion: The most frequent indications for non invasive ventilation obsesrved were acute pulmonary edema and pneumoniae in inmunocompromised patients. The elaboration of protocols to guide the correct use of this ventilations method is needed.