Efecto de la ventilación mecánica en la variabilidad de la oximetría de pulso en el posoperatorio de cirugía cardiaca

To describe whether mechanical ventilation participates in the variability of pulse oximetry in subjects in critical conditions.

Postoperative cardiac surgery subjects with and without mechanical ventilation were analized; their demographic variables, heart rate and arterial blood gases were defined. Variability was obtained from the comparison of arterial saturation (SaO₂) and partial oxygen saturation (SpO₂). They were obtained from blood gases, a pocket-sized Nonin pulse oximeter, and a Phillips monitor. It was analyzed with the Bland-Altman procedure.

260 subjects and 780 pairs of comparisons were studied. The mean difference (bias) with and without mechanical ventilation: SaO₂ monitor 0.0 (6.3, -6.3) vs. 0.1 (6.3, -6.2); SaO₂ Nonin 1.2 (7.7, -5.3) vs. 1.4 (7.2, -4.4); SpO₂ Nonin - SpO₂ monitor 1.2 (6.6, -4.2) vs. 1.3 (5.8, -3.2). The heart rate: auscultation monitor -0.5 (3.6, -4.5) vs. -0.1 (3, -3.3); auscultation Nonin -1.1 (7.4, -9.7) vs. -0.8 (4.2, -5.7); monitor - Nonin -0.6 (3, -4.3) vs. -0.6 (3, -4.3).

Mechanical ventilation does not increase heart rate or partial oxygen saturation variability in critically ill subject's post-cardiac surgery.