title: Change in regional (somatic) near-infrared spectroscopy is not a useful indicator of clinically detectable low cardiac output in children after surgery for congenital heart defects.
abstract: OBJECTIVE
  Near-infrared spectroscopy correlation with low cardiac output has not been validated. Our objective was to determine role of splanchnic and/or renal oxygenation monitoring using near-infrared spectroscopy for detection of low cardiac output in children after surgery for congenital heart defects.
  
  
  METHODS
  Prospective observational study.
  
  
  METHODS
  Pediatric intensive care unit of a tertiary care teaching hospital.
  
  
  METHODS
  Children admitted to the pediatric intensive care unit after surgery for congenital heart defects.
  
  
  METHODS
  None.
  
  
  RESULTS
  We hypothesized that splanchnic and/or renal hypoxemia detected by near-infrared spectroscopy is a marker of low cardiac output after pediatric cardiac surgery. Patients admitted after cardiac surgery to the pediatric intensive care unit over a 10-month period underwent serial splanchnic and renal near-infrared spectroscopy measurements until extubation. Baseline near-infrared spectroscopy values were recorded in the first postoperative hour. A near-infrared spectroscopy event was a priori defined as ≥20% drop in splanchnic and/or renal oxygen saturation from baseline during any hour of the study. Low cardiac output was defined as metabolic acidosis (pH <7.25, lactate >2 mmol/L, or base excess ≤-5), oliguria (urine output <1 mL/kg/hr), or escalation of inotropic support. Receiver operating characteristic analysis was performed using near-infrared spectroscopy event as a diagnostic test for low cardiac output. Twenty children were enrolled: median age was 5 months; median Risk Adjustment for Congenital Heart Surgery category was 3 (1-6); median bypass and cross-clamp times were 120 mins (45-300 mins) and 88 mins (17-157 mins), respectively. Thirty-one episodes of low cardiac output and 273 near-infrared spectroscopy events were observed in 17 patients. The sensitivity and specificity of a near-infrared spectroscopy event as an indicator of low cardiac output were 48% (30%-66%) and 67% (64%-70%), respectively. On receiver operating characteristic analysis, neither splanchnic nor renal near-infrared spectroscopy event had a significant area under the curve for prediction of low cardiac output (area under the curve: splanchnic 0.45 [95% confidence interval 0.30-0.60], renal 0.51 [95% confidence interval 0.37-0.65]).
  
  
  CONCLUSIONS
  Splanchnic and/or renal hypoxemia as detected by near-infrared spectroscopy may not be an accurate indicator of low cardiac output after surgery for congenital heart defects.
authors.affiliation: Department of Anesthesiology and Critical Care, The Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA. usbhalala@gmail.com
authors.forename: Utpal S
authors.initials: US
authors.lastname: Bhalala
authors.forename: Akira
authors.initials: A
authors.lastname: Nishisaki
authors.forename: Derrick
authors.initials: D
authors.lastname: McQueen
authors.forename: Geoffrey L
authors.initials: GL
authors.lastname: Bird
authors.forename: Wynne E
authors.initials: WE
authors.lastname: Morrison
authors.forename: Vinay M
authors.initials: VM
authors.lastname: Nadkarni
authors.forename: Meena
authors.initials: M
authors.lastname: Nathan
authors.forename: Joanne P
authors.initials: JP
authors.lastname: Starr
mesh_terms: D000138:Acidosis / Q000097:blood / Q000175:diagnosis; D000293:Adolescent; D019540:Area Under Curve; D002303:Cardiac Output, Low / Q000097:blood / Q000175:diagnosis*; D002316:Cardiotonic Agents / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D016001:Confidence Intervals; D005260:Female; D006330:Heart Defects, Congenital / Q000601:surgery; D006801:Humans; D000860:Hypoxia / Q000097:blood / Q000175:diagnosis*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D010100:Oxygen / Q000097:blood*; D011183:Postoperative Complications / Q000097:blood / Q000175:diagnosis*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D012372:ROC Curve; D012079:Renal Circulation; D019265:Spectroscopy, Near-Infrared; D013152:Splanchnic Circulation
chemical_list: D002316:Cardiotonic Agents; D010100:Oxygen