Predictores de éxito del tratamiento con cánula nasal de alto flujo en el fallo respiratorio agudo hipoxémico / Predictors of success of high-flow nasal cannula in the treatment of acute hypoxemic respiratory failure

Introducción: La terapia con cánula nasal de alto flujo (CNAF) se ha introducido recientemente en el tratamiento del fallo respiratorio agudo (FRA), siendo una técnica segura, confortable y eficaz que logra revertir la hipoxemia en estos pacientes. Es necesario disponer de herramientas que nos permitan detectar precozmente el fallo de este tipo de tratamiento para evitar el incremento de la mortalidad que puede conllevar. El objetivo primario de este estudio ha sido analizar el impacto que la frecuencia respiratoria (FR), la saturación periférica de oxígeno (SpO2), la fracción inspirada de oxígeno (FiO2) y el índice ROX (IROX=[SpO2/FiO2]/FR) tienen sobre el éxito de la CNAF en los pacientes con FRA hipoxémico. Los objetivos secundarios han sido analizar la estancia y la mortalidad en la UCI y la necesidad de ventilación mecánica (VM). Material y métodos Se trata de un estudio retrospectivo efectuado en una UCI polivalente del Hospital Comarcal de Montilla (Córdoba). Se incluyeron los pacientes tratados con CNAF por FRA hipoxémico desde enero de 2016 hasta enero de 2018.ResultadosDesde enero de 2016 hasta enero de 2018 se trataron 27 pacientes con FRA, de los cuales 19 (70,37%) presentaban FRA hipoxémico. De estos, 15 (78,95%) respondieron bien al tratamiento y 4 (21,05%) fracasaron. A las 2h de tratamiento la FR demostró ser el mejor predictor (área bajo la curva ROC [AUROC] 0,858; IC95%: 0,63-1,05; p=0,035). La FiO2 y el IROX fueron buenos predictores a las 8h de tratamiento (FiO2: AUROC 0,95; IC95%: 0,85-1,04; p=0,007, e IROX: AUROC 0,967; IC95%: 0,886-1,047; p=0,005). El mejor punto de corte de la FR a la segunda hora fue de 29 respiraciones/min (sensibilidad 75%, especificidad 87%). El mejor punto de corte de la FiO2 a las 8h de tratamiento fue de 0,59 (75% sensibilidad, 93% especificidad). El mejor punto de corte para IROX a las 8h de tratamiento fue de 5,98 (sensibilidad 100%, especificidad 75%). ... (AU)

Background: High-flow nasal cannula (HFNC) therapy is used in the treatment of acute respiratory failure (ARF) and is both safe and effective in reversing hypoxemia. In order to minimize mortality and clinical complications associated to this practice, a series of tools must be developed to allow early detection of failure. The present study was carried out to: (i)examine the impact of respiratory rate (RR), peripheral oxygen saturation (SpO2), ROX index (ROXI=[SpO2/FiO2]/RR) and oxygen inspired fraction (FiO2) on the success of HFNC in patients with hypoxemic ARF; and (ii)analyze the length of stay and mortality in the ICU, and the need for mechanical ventilation (MV).MethodsA retrospective study was carried out in the medical-surgical ICU of Hospital de Montilla (Córdoba, Spain). Patients diagnosed with hypoxemic ARF and treated with HFNC from January 2016 to January 2018 were included.ResultsOut of 27 patients diagnosed with ARF, 19 (70.37%) had hypoxemic ARF. Fifteen of them (78.95%) responded satisfactorily to HFNC, while four (21.05%) failed. After two hours of treatment, RR proved to be the best predictor of success (area under the ROC curve [AUROC] 0.858; 95%CI: 0.63-1.05; P=.035). For this parameter, the optimal cutoff point was 29rpm (sensitivity 75%, specificity 87%). After 8hours of treatment, FiO2 and ROXI were reliable predictors of success (FiO2: AUROC 0.95; 95%CI: 0.85-1.04; P=.007 and ROXI: AUROC 0.967; 95%CI: 0.886-1.047; P=.005). In the case of FiO2 the optimal cutoff point was 0.59 (sensitivity 75%, specificity 93%), while the best cutoff point for ROXI was 5.98 (sensitivity 100%, specificity 75%). Using a Cox regression model, we found RR<29rpm after two hours of treatment, and FiO2<0.59 and ROXI>5.98 after 8hours of treatment, to be associated with a lesser risk of MV (RR: HR 0.103; 95%CI: 0.11-0.99; P=.05; FiO2: HR 0.053; 95%CI: 0.005-0.52; P=.012; and ROXI: HR 0.077; 95%CI: 0.008-0.755; P=.028, respectively). ... (AU)

Predictors of success of high-flow nasal cannula in the treatment of acute hypoxemic respiratory failure. / Predictores de éxito del tratamiento con cánula nasal de alto flujo en el fallo respiratorio agudo hipoxémico.

BACKGROUND: High-flow nasal cannula (HFNC) therapy is used in the treatment of acute respiratory failure (ARF) and is both safe and effective in reversing hypoxemia. In order to minimize mortality and clinical complications associated to this practice, a series of tools must be developed to allow early detection of failure. The present study was carried out to: (i)examine the impact of respiratory rate (RR), peripheral oxygen saturation (SpO2), ROX index (ROXI=[SpO2/FiO2]/RR) and oxygen inspired fraction (FiO2) on the success of HFNC in patients with hypoxemic ARF; and (ii)analyze the length of stay and mortality in the ICU, and the need for mechanical ventilation (MV). METHODS: A retrospective study was carried out in the medical-surgical ICU of Hospital de Montilla (Córdoba, Spain). Patients diagnosed with hypoxemic ARF and treated with HFNC from January 2016 to January 2018 were included. RESULTS: Out of 27 patients diagnosed with ARF, 19 (70.37%) had hypoxemic ARF. Fifteen of them (78.95%) responded satisfactorily to HFNC, while four (21.05%) failed. After two hours of treatment, RR proved to be the best predictor of success (area under the ROC curve [AUROC] 0.858; 95%CI: 0.63-1.05; P=.035). For this parameter, the optimal cutoff point was 29rpm (sensitivity 75%, specificity 87%). After 8hours of treatment, FiO2 and ROXI were reliable predictors of success (FiO2: AUROC 0.95; 95%CI: 0.85-1.04; P=.007 and ROXI: AUROC 0.967; 95%CI: 0.886-1.047; P=.005). In the case of FiO2 the optimal cutoff point was 0.59 (sensitivity 75%, specificity 93%), while the best cutoff point for ROXI was 5.98 (sensitivity 100%, specificity 75%). Using a Cox regression model, we found RR<29rpm after two hours of treatment, and FiO2<0.59 and ROXI>5.98 after 8hours of treatment, to be associated with a lesser risk of MV (RR: HR 0.103; 95%CI: 0.11-0.99; P=.05; FiO2: HR 0.053; 95%CI: 0.005-0.52; P=.012; and ROXI: HR 0.077; 95%CI: 0.008-0.755; P=.028, respectively). CONCLUSIONS: RR after two hours of treatment, and FiO2 and ROXI after 8hours of treatment, were the best predictors of success of HFNC. RR<29rpm, FiO2<0.59 and ROXI>5.98 were associated with a lesser risk of MV.