Core-Peripheral Temperature Gradient and Skin Temperature as Predictors of Major Adverse Events Among Postoperative Pediatric Cardiac Patients

Objective: During episodes of low cardiac output, sympathetic neurohumoral responses with peripheral vasoconstriction result in an increase in the core-peripheral temperature gradient (CPTG). However, assessment of CPTG as a surrogate of low cardiac output and a predictor of outcomes in pediatric cardiac patients rarely has been performed. In this retrospective study, the authors assessed the prognostic abilities of CPTG, skin temperature, and serum lactate level for predicting clinical outcomes. Design: A retrospective single-center study. Setting: Referral high-volume pediatric center. Patients: Patients younger than four months of age with congenital heart disease who underwent cardiac surgery with cardiopulmonary bypass. Interventions: None. Measurements and Main Results: The primary outcome was a composite of one or more of the following major adverse events (MAEs) that occurred within seven days after surgery: death from any cause, cardiac arrest, emergency chest reopening, and requirement for extracorporeal membrane oxygenation. A total of 661 patients were included in the study. Univariate logistic regression analyses showed no significant difference in the odds for MAEs with CPTG at admission and at six hours after surgery and in the odds for MAEs with skin temperature at admission. On the other hand, the odds for MAEs increased significantly with increase in serum lactate level at admission (odds ratio [OR]: 1.54, 95% confidence interval [CI]: 1.26-1.87, p < 0.001) and at six hours after surgery (OR: 1.94, 95% CI: 1.50-2.51, p < 0.001). Areas under the receiver operating curve at admission for predicting MAEs were 0.531 for CPTG, 0.557 for skin temperature, and 0.713 for serum lactate. Multivariate logistic regression analysis showed neither CPTG nor skin temperature at any time point was significantly associated with MAEs. Conclusions: Both CPTG and skin temperature had low performance for prediction of MAEs in children after cardiac surgery. Either of those markers, especially at admission, should not be used as a single marker for assessing the condition of a patient.