Alveolar recruitment: impact on respiratory mechanics and oxygenation of mechanically ventilated patients

Abstract

INTRODUCTION: The sigh is characterized by a slow and deep inhalation, followed by a slow exhalation. Studies suggest that the addition of one breath per minute in patients with acute respiratory distress syndrome, ventilated on PSV, improves oxygenation and pulmonary mechanics. OBJECTIVE: Analyze the impact of the alveolar recruitment maneuver through breath in pulmonary mechanics and oxygenation in mechanically ventilated patients, in addition to checking the hemodynamic impact and the incidence of complications associated with the use of the technique. MATERIALS AND METHODS: Experimental study with 17 patients on mechanical ventilation, showing a relationship between partial pressure of alveolar oxygen and fraction of inspired oxygen (PaO₂/FiO₂) below 300mmHg. Respiratory, pulmonary mechanics and hemodynamic data were evaluated. Data were collected during three periods: before sigh, immediately after and 15 minutes after the technique. Two sighs per minute were administered using airways pressure limited to 40 cmH₂O, during an inspiratory time of four seconds. RESULTS: After the sigh there was an increase in PaO2, resistive pressure, static compliance and PaO₂/FiO₂ ratio, in addition to a decrease in plateau pressure and partial pressure of alveolar carbon dioxide (PaCO₂). After 15 minutes of sigh removal, it was observed that PaO₂, resistive pressure, static compliance and PaO₂/FiO₂ ratio remained above the baseline, while the plateau pressure remained below. There was no significant change in hemodynamic variables. CONCLUSION: The sigh in mechanically ventilated patients was able to improve oxygenation and pulmonary mechanics, without compromising hemodynamic stability.