title: Monitoring of regional tissue oxygenation with near-infrared spectroscopy during the early postoperative course after superior cavopulmonary anastomosis.
abstract: OBJECTIVE
  Near-infrared spectroscopy (NIRS) offers continuous non-invasive monitoring of regional tissue oxygenation. We evaluated NIRS monitoring during the postoperative course after superior cavopulmonary anastomosis in patients with hypoplastic left heart syndrome and anatomically related malformations.
  
  
  METHODS
  Cerebral (cSO(2)) and somatic (sSO(2)) tissue oxygenations were recorded for 48 h and compared with routine measures of intensive care monitoring. Changes in parameters in the case of postoperative complications were evaluated.
  
  
  RESULTS
  Data were obtained from 32 patients. Median age at operation was 2.9 (1.5-10.0) months and weight was 5.3 ± 1.0 kg. Postoperative complications occurred in 7 patients (pulmonary artery thrombus n = 4, pneumothorax n = 1, cardiopulmonary resuscitation n = 1 and low-cardiac output n = 1). cSO(2) was 44 ± 14% at the end of the operation and reached its minimum of 40 ± 11% 2 h later (P = 0.018). Overall, cSO(2) was depressed early after surgery and increased from a mean of 42 ± 11% during the first 4 postoperative hours to 57 ± 8% in the last 4 h of the study period (P < 0.001). The sSO(2) decreased from 77 ± 11% during the early postoperative course to 68 ± 9% within the later course (P < 0.001). The cSO(2) correlated with the arterial partial pressure of oxygen (pO(2), r = 0.364, P < 0.001), with the arterial oxygen saturation (SaO(2), r = 0.547, P < 0.001) and with the central venous oxygen saturation providing the strongest correlation (SvO(2), r = 0.686, P < 0.001). Analysis of agreement between cSO(2) and SvO(2) measurements revealed a mean bias of 0.97 with limits of agreement between 19.8 and -17.9%. Inclusion of both cSO(2) and sSO(2) into a linear regression model slightly improved the prediction of SvO(2) from NIRS values (r = 0.706, P < 0.001). The mean values of cSO(2), sSO(2), SaO(2) and SvO(2) during the early postoperative period were lower in patients with complications (cSO(2): 45 ± 9 vs 29 ± 5%, P < 0.001; sSO(2): 80 ± 11 vs 70 ± 6%, P = 0.004; SaO(2): 76 ± 8 vs 66 ± 6%, P = 0.004; SvO(2): 48 ± 14 vs 32 ± 6%, P < 0.001).
  
  
  CONCLUSIONS
  NIRS technology allows inferring the global oxygenation from continuous non-invasive measurements of regional tissue oxygenation. The cSO(2) is lowered in the early postoperative course. Lower cSO(2) values in the early postoperative course may be predictive of postoperative complications.
authors.affiliation: Department of Congenital Heart Disease and Pediatric Cardiology, University Hospital Schleswig-Holstein, Kiel, Germany. jan.hansen@uk-sh.de
authors.forename: Jan Hinnerk
authors.initials: JH
authors.lastname: Hansen
authors.forename: Jana
authors.initials: J
authors.lastname: Schlangen
authors.forename: Sven
authors.initials: S
authors.lastname: Armbrust
authors.forename: Olaf
authors.initials: O
authors.lastname: Jung
authors.forename: Jens
authors.initials: J
authors.lastname: Scheewe
authors.forename: Hans-Heiner
authors.initials: HH
authors.lastname: Kramer
mesh_terms: D001794:Blood Pressure / Q000502:physiology; D003422:Critical Care; D018610:Heart Bypass, Right / Q000379:methods*; D006330:Heart Defects, Congenital / Q000503:physiopathology / Q000601:surgery*; D006801:Humans; D018636:Hypoplastic Left Heart Syndrome / Q000503:physiopathology / Q000601:surgery; D007223:Infant; D016343:Monitoring, Intraoperative / Q000379:methods; D061646:Operative Time; D010100:Oxygen / Q000032:analysis*; D010313:Partial Pressure; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000209:etiology* / Q000503:physiopathology; D012189:Retrospective Studies; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
chemical_list: D010100:Oxygen