Correlation and validity of imputed PaO2/FiO2 and SpO2/FiO2 in patients with invasive mechanical ventilation at 2600m above sea level.

OBJECTIVE: To establish the correlation and validity between PaO2/FiO2 obtained on arterial gases versus noninvasive methods (linear, nonlinear, logarithmic imputation of PaO2/FiO2 and SpO2/FiO2) in patients under mechanical ventilation living at high altitude. DESIGN: Ambispective descriptive multicenter cohort study. SETTING: Two intensive care units (ICU) from Colombia at 2600m a.s.l. PATIENTS OR PARTICIPANTS: Consecutive critically ill patients older than 18 years with at least 24h of mechanical ventilation were included from June 2016 to June 2019. INTERVENTIONS: None. VARIABLES: Variables analyzed were demographic, physiological messures, laboratory findings, oxygenation index and clinical condition. Nonlinear, linear and logarithmic imputation formulas were used to calculate PaO2 from SpO2, and at the same time the SpO2/FiO2 by severe hypoxemia diagnosis. The intraclass correlation coefficient, area under the ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were calculated. RESULTS: The correlation between PaO2/FiO2 obtained from arterial gases, PaO2/FiO2 derived from one of the proposed methods (linear, non-linear, and logarithmic formula), and SpO2/FiO2 measured by the intraclass correlation coefficient was high (greater than 0.77, p<0.001). The different imputation methods and SpO2/FiO2 have a similar diagnostic performance in patients with severe hypoxemia (PaO2/FiO2 <150). PaO2/FiO2 linear imputation AUC ROC 0,84 (IC 0.81-0.87, p<0.001), PaO2/FiO2 logarithmic imputation AUC ROC 0.84 (IC 0.80-0.87, p<0.001), PaO2/FiO2 non-linear imputation AUC ROC 0.82 (IC 0.79-0.85, p<0.001), SpO2/FiO2 oximetry AUC ROC 0.84 (IC 0.81-0.87, p<0.001). CONCLUSIONS: At high altitude, the SaO2/FiO2 ratio and the imputed PaO2/FiO2 ratio have similar diagnostic performance in patients with severe hypoxemia ventilated by various pathological conditions.

Correlation and validity of imputed PaO2/FiO2 and SpO2/FiO2 in patients with invasive mechanical ventilation at 2600m above sea level.

OBJECTIVE: To establish the correlation and validity between PaO2/FiO2 obtained on arterial gases versus noninvasive methods (linear, nonlinear, logarithmic imputation of PaO2/FiO2 and SpO2/FiO2) in patients under mechanical ventilation living at high altitude. DESIGN: Ambispective descriptive multicenter cohort study. SETTING: Two intensive care units (ICU) from Colombia at 2600m a.s.l. PATIENTS OR PARTICIPANTS: Consecutive critically ill patients older than 18 years with at least 24h of mechanical ventilation were included from June 2016 to June 2019. INTERVENTIONS: None. VARIABLES: Variables analyzed were demographic, physiological messures, laboratory findings, oxygenation index and clinical condition. Nonlinear, linear and logarithmic imputation formulas were used to calculate PaO2 from SpO2, and at the same time the SpO2/FiO2 by severe hypoxemia diagnosis. The intraclass correlation coefficient, area under the ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were calculated. RESULTS: The correlation between PaO2/FiO2 obtained from arterial gases, PaO2/FiO2 derived from one of the proposed methods (linear, non-linear, and logarithmic formula), and SpO2/FiO2 measured by the intraclass correlation coefficient was high (greater than 0.77, p<0.001). The different imputation methods and SpO2/FiO2 have a similar diagnostic performance in patients with severe hypoxemia (PaO2/FiO2 <150). PaO2/FiO2 linear imputation AUC ROC 0,84 (IC 0.81-0.87, p<0.001), PaO2/FiO2 logarithmic imputation AUC ROC 0.84 (IC 0.80-0.87, p<0.001), PaO2/FiO2 non-linear imputation AUC ROC 0.82 (IC 0.79-0.85, p<0.001), SpO2/FiO2 oximetry AUC ROC 0.84 (IC 0.81-0.87, p<0.001). CONCLUSIONS: At high altitude, the SaO2/FiO2 ratio and the imputed PaO2/FiO2 ratio have similar diagnostic performance in patients with severe hypoxemia ventilated by various pathological conditions.

Correlation and validity of imputed PaO2/FiO2 and SpO2/FiO2 in patients with invasive mechanical ventilation at 2600m above sea level / Correlación y validez de la PaO2/FiO2 y SpO2/FiO2 imputadas en pacientes con ventilación mecánica invasiva a 2.600 metros sobre el nivel del mar

Objective To establish the correlation and validity between PaO2/FiO2 obtained on arterial gases versus noninvasive methods (linear, nonlinear, logarithmic imputation of PaO2/FiO2 and SpO2/FiO2) in patients under mechanical ventilation living at high altitude. Design Ambispective descriptive multicenter cohort study. Setting Two intensive care units (ICU) from Colombia at 2600m a.s.l. Patients or participants Consecutive critically ill patients older than 18 years with at least 24h of mechanical ventilation were included from June 2016 to June 2019. Interventions None. Variables Variables analyzed were demographic, physiological messures, laboratory findings, oxygenation index and clinical condition. Nonlinear, linear and logarithmic imputation formulas were used to calculate PaO2 from SpO2, and at the same time the SpO2/FiO2 by severe hypoxemia diagnosis. The intraclass correlation coefficient, area under the ROC curve, sensitivity, specificity, positive predictive value, negative predictive value, positive and negative likelihood ratio were calculated. Results The correlation between PaO2/FiO2 obtained from arterial gases, PaO2/FiO2 derived from one of the proposed methods (linear, non-linear, and logarithmic formula), and SpO2/FiO2 measured by the intraclass correlation coefficient was high (greater than 0.77, p<0.001). The different imputation methods and SpO2/FiO2 have a similar diagnostic performance in patients with severe hypoxemia (PaO2/FiO2 <150). PaO2/FiO2 linear imputation AUC ROC 0,84 (IC 0.81–0.87, p<0.001), PaO2/FiO2 logarithmic imputation AUC ROC 0.84 (IC 0.80–0.87, p<0.001), PaO2/FiO2 non-linear imputation AUC ROC 0.82 (IC 0.79–0.85, p<0.001), SpO2/FiO2 oximetry AUC ROC 0.84 (IC 0.81–0.87, p<0.001). Conclusions At high altitude, the SaO2/FiO2 ratio and the imputed PaO2/FiO2 ratio have similar diagnostic performance in patients with severe hypoxemia ventilated by various pathological conditions (AU)

Objetivo Establecer la correlación y validez entre PaO2/FiO2 obtenida en gases arteriales versus métodos no invasivos (imputación lineal, no lineal, logarítmica de PaO2/FiO2 y SpO2/FiO2) en pacientes bajo ventilación mecánica que viven en altitudes elevadas. Diseño Estudio de cohorte multicéntrico descriptivo ambispectivo Ámbito Dos unidades de cuidados intensivos de Colombia a 2.600 m s.n.m. Pacientes o participantes Se incluyeron pacientes consecutivos en estado crítico mayores de 18 años con al menos 24h de ventilación mecánica desde junio de 2016 a junio de 2019. Intervenciones Ninguna. Variables Las variables analizadas fueron demográficas, fisiológicas, hallazgos de laboratorio, índice de oxigenación y estado clínico. Se utilizaron fórmulas de imputación no lineales, lineales y logarítmicas para calcular la PaO2 a partir de la SpO2, y al mismo tiempo la SpO2/FiO2 mediante el diagnóstico de hipoxemia severa. Se calculó el coeficiente de correlación intraclase, el área bajo la curva ROC, la sensibilidad, la especificidad, el valor predictivo positivo, el valor predictivo negativo, la razón de verosimilitud positiva y negativa. Resultados La correlación entre PaO2/FiO2 obtenida a partir de gases arteriales, PaO2/FiO2 derivada de uno de los métodos propuestos (fórmula lineal, no lineal y logarítmica) y SpO2/FiO2 medida por el coeficiente de correlación intraclase fue alta (mayor a 0,77, p<0,001). Los diferentes métodos de imputación y SpO2/FiO2 tienen un rendimiento diagnóstico similar en pacientes con hipoxemia severa (PaO2/FiO2<150). PaO2/FiO2 imputación lineal AUC ROC 0,84 (IC 0,81-0,87; p<0,001), PaO2/FiO2 imputación logarítmica AUC ROC 0,84 (IC 0,80-0,87; p<0,001), PaO2/Imputación no lineal de FiO2 AUC ROC 0,82 (IC 0,79-0,85; p<0,001), oximetría de SpO2/FiO2 AUC ROC 0,84 (IC 0,81-0,87; p<0,001). Conclusiones A gran altitud, el cociente SaO2/FiO2 y el cociente PaO2/FiO2 (AU)