Reliability of Pulse Oximetry during Progressive Hypoxia, Cardiopulmonary Resuscitation, and Recovery in a Piglet Model of Neonatal Hypoxic Cardiac Arrest

Abstract

Background: Pulse oximetry is widely used in intensive care and emergency conditions to monitor arterial oxygenation and to guide oxygen therapy. Objective: To study the reliability of pulse oximetry in comparison with CO-oximetry in newborn piglets during progressive hypoxia, cardiac arrest, cardiopulmonary resuscitation (CPR), and after return of spontaneous circulation (ROSC). Methods: Thirty-three newborn piglets were exposed to hypoxia until asystole occurred and then resuscitated until ROSC. Arterial oxygen saturation was monitored continuously by pulse oximetry (SpO₂) with one sensor applied to the wrist of the right forelimb (FL) and another to the thigh of the left hind limb (HL). Arterial functional oxygen saturation (SaO₂) was measured at baseline and at predefined intervals during each phase of the experiment. SpO₂ was compared with coinciding SaO₂ values and bias considered whenever the difference (SpO₂ - SaO₂) was beyond ±5%. Results: Bias values were lower at the baseline measurements (-3.7 ± 2.3% in FL and -4.1 ± 3.4% in HL) as well as after ROSC (1.5 ± 4.2% in FL and 0.2 ± 4.6% in HL) with higher precision and accuracy than during other experiment phases. During hypoxia induction, cardiac arrest, and CPR, there was a marked decrease in precision and accuracy as well as an increase in bias up to 43 ± 26 and 56 ± 27% in FL and HL, respectively, over a range of SaO₂ from 13 to 51%. Conclusion: Pulse oximetry showed increased bias and decreased accuracy and precision during marked hypoxemia in a model of neonatal hypoxic cardiac arrest.

Accuracy of pulse oximetry in preterm and term infants is insufficient to determine arterial oxygen saturation and tension

“…The error increased to nearly 40% points at SaO 2 levels of 50% 25,26 . Current studies in piglets showed that PO errors increased with the duration of hypoxaemia 27 . Our findings were similar in terms of the PaO 2 .…”

“…25,26 Current studies in piglets showed that PO errors increased with the duration of hypoxaemia. 27 Our findings were similar in terms of the PaO 2 . PO readings showed increasing difference at PaO 2 levels below 8 kPa.…”

Hypoxic preacclimatization combining intermittent hypoxia exposure and physical exercise significantly improves hypoxic tolerance

“…Hypoxic preacclimatization has probably resulted in an acclimation response with shorter time than predicted. Nevertheless, it should be noted that although SpO 2 is signi cantly correlated with SaO 2 in most cases, it may not be reliable surrogate marker for SaO 2 in critically ill patients as well as in hypoxemia for increased bias and decreased accuracy and precision [24,25]. HRs of the subjects with 5-day rest were signi cantly lowered as compared with the controls, however, no matter 5 days or 3 days of physical exercise seemed to have no obvious effect on HR.…”

Hypoxic preacclimatization combining intermittent hypoxia exposure with physical exercise significantly promotes the tolerance to acute hypoxia

“…Hypoxic preacclimatization has probably resulted in an acclimatization response with shorter time than predicted. Nevertheless, it should be noted that although SpO 2 is significantly correlated with SaO 2 in most cases, it may not be reliable surrogate marker for SaO 2 in critically ill patients as well as in hypoxemia for increased bias and decreased accuracy and precision ( Hassan et al, 2017 ; Kanz et al, 2018 ). HR of the subjects with 5-day rest was significantly lowered as compared with the controls, however, no matter 5-day or 3-day physical exercise in the hypobaric chamber seemed to have no obvious effect on HR.…”