Endotracheal aspiration: respirator vs. manual resuscitation as method for hyperoxygenation and hyperinflation

Endotracheal aspiration protocols (EAT) include hyperoxygenation and hyperinflation to minimize the negative effects of the technique. No conclusive studies have determined the most effective hyperoxygenation and hyperinflation method. This study had two aims: to compare the effects on patient oxygenation and hemodynamics during endotracheal aspiration of secretions using, respectively, a respirator or manual resuscitator as the hyperoxygenation and hyperinflation method. Tidal volume (TV) and FIO2 with the manual resuscitator were quantified. The study was based on 172 aspiration sessions carried out under artificial ventilation in the immediate postoperative period of 26 patients who had undergone cardiac surgery without lung damage. Hyperinflation and hyperoxygenation before, during and after aspiration were carried out with and artificial ventilator in group I and with a manual resuscitator in group II. In all aspiration interventions, an analysis was made of hemodynamic parameters (MAP, MPAP, HR, CO and arrhythmias), ventilation and oxygenation parameters (HR, FIO2, SpO2, and SvO2), and the influence of the method on the appearance of atelectasis. Both methods produced small increases in all hemodynamic parameters, and significant differences in HR (p < 0.001) and MPAP (p < 0.002), although no clinical repercussions were observed. No severe arrhythmias were observed. No statistically significant differences between the two methods were found in the evolution of SpO2 and SvO2, which remained above baseline levels throughout both procedures. Analysis of the effectiveness of the manual resuscitator (the second aim) under the conditions established yielded a mean FIO2 of 0.86 and a mean tidal volume of 153% in relation to baseline tidal volume. Both methods of hyperoxygenation and hyperinflation prevent hypoxia and maintain hemodynamic stability in patients without producing lung damage. The effectiveness of the manual resuscitator for administering high oxygen concentration and large volumes was confirmed.