Pulsioximetría más gasometría venosa vs gasometría arterial para el manejo terapéutico de la insuficiencia respiratoria aguda

Abstract

Acute respiratory failure (ARF) is classified into two main types: type I or hypoxemic ARI and type II or hypercapnic ARI. The treatment chosen in its management depends on the pathophysiological status of the patient and his level of oxygenation, which is measured by PaO2 / FIO2. And since the SpO2 contributes in essence, the same information as the PaO2, it would be expected that the PaO2 / FiO2 ratio will be replaceable by the SpO2 / FiO2. Arterial blood gases also provide information on ventilation through pH and pCO2. There are studies that have tried to "arterialize" the venous blood gas with the aim that it could replace the arterial one. However, these studies are not conclusive. There is no information or studies to find out if the clinician&apos;s attitude changes according to the information provided by arterial blood gases with respect to that given by SpO2 + venous blood gases. The objective of this study was to establish whether in patients with acute respiratory failure, the use of SpO2 together with venous blood gases, in comparison with arterial blood gases, does not substantially modify the therapeutic attitude of the clinician. A prospective observational analytical study of cohorts was developed in the Emergency Services of two hospitals in Murcia. It started in 2015 and ended in December 2017. It was divided into two phases. In the first, we proceeded to the inclusion of patients, noting the SpO2 and the arrival FiO2. In the second phase, a series of clinical cases was written in paired: one with the arterial blood gas information and the other with the information of the SpO2 + venous blood gas. These cases were delivered to four experts who had to choose four therapeutic options: conventional oxygen therapy, CPAP, Bi-Level or invasive mechanical ventilation 142 cases were recruited, leaving 105 (74.0%) after the losses. The mean age of the patients was 76.31 16.35 years. The median for men&apos;s age was 78 years and 83 for women (p = 0.006). The correlations between arterial and venous pH, pCO2 and HCO3 were 0.940, 0.917 and 0.894 (p <0.001). The concordance, measured through the Kappa index, of each clinician in their therapeutic options based on the information from arterial blood gases and venous blood gas analysis + SpO2 was: for the pulmonologist 0.795 (p <0.001); for the hospital emergency doctor nº1 of 0.820 (p <0.001); for the intensive care physician of 0.874 (p <0.001); and for the hospital emergency doctor nº2 of 0.712 (p <0.001). The variable "some discrepancy" was defined when a single physician did not agree with any of its prescriptions. In 89 patients (84.8%) there were no discrepancies in the therapeutic management. The variables that were associated with "some discrepancy" were the patient&apos;s regular or poor general condition (RR: 0.794, CI: 95% 0.651 - 0.968, p = 0.008) and respiratory rate higher than 18 rpm (RR 0.308, IC 95 %: 0.102 - 0.932, p = 0.039). The conclusion was that patients with acute respiratory failure, the use of SpO2 together with venous blood gas analysis, compared with arterial blood gas analysis, did not substantially modify the therapeutic attitude of the clinician and that the correlation between arterial pH and pCO2 and Venous was excellent.