Low near infrared spectroscopic somatic oxygen saturation at admission is associated with need for lifesaving interventions among unplanned admissions to the pediatric intensive care unit.

Abstract

To investigate the association between low near infrared spectroscopy (NIRS) somatic oxygen saturation (<70%) at admission and the need for lifesaving interventions (LSI) in the initial 24h of a PICU admission. Retrospective chart review of all unplanned admissions to the pediatric intensive care unit (PICU) with NIRS somatic oxygen saturation data available within 4h of admission, excluding admissions with a cardiac diagnosis. LSI data were collected for the first 24h after admission. Hemodynamic parameters, laboratory values, illness severity scores and diagnoses were collected. Included PICU admissions were stratified by lowest NIRS value in the first 4h after admission: low NIRS (<70%) and normal NIRS (≥70%) groups. Rate of LSI from 4h to 24h was compared between the two groups. Association of LSI with NIRS saturation and other clinical and laboratory parameters was measured by univariate and multivariate methods. We reviewed 411 consecutive unplanned admissions to the PICU of which 184 (44%) patients underwent NIRS monitoring. A higher proportion of patients who underwent somatic NIRS monitoring required LSIs compared to those without NIRS monitoring (36.4 vs 5.7% respectively, p < 0.0001). The proportion of patients who required LSI was higher in the group with low NIRS (<70%) within the first 4h compared to those with normal NIRS (≥70%) (77.1 vs 22.1%, p < 0.0001). Fluid resuscitation, blood products and vasoactive medications were the most common LSIs. Multivariable modeling showed NIRS < 70% and heart rate > 2SD for age to be associated with LSIs. ROC curve analysis of the combination of NIRS<70% and HR >2SD for age had an area under the curve of 0.79 with 78% sensitivity and 76% specificity for association with LSI. Compared to the normal NIRS group, the low NIRS group had higher mortality (10.4 vs 0.7%, p = 0.005) and longer median hospital length of stay (2.9 vs 1.6days, p < 0.0001). Low somatic NIRS oxygen saturation (<70%) in the first 4h of an unplanned PICU admission is associated with need for higher number of subsequent lifesaving interventions up to 24h after admission. Noninvasive, continuous, somatic NIRS monitoring may identify children at high risk of medical instability.