Cerebral desaturation during neonatal congenital heart surgery is associated with perioperative brain structure alterations but not with neurodevelopmental outcome at 1 year.

OBJECTIVES: The significance of intraoperative cerebral desaturation (CD) measured by near-infrared spectroscopy (NIRS) to predict neurological outcome after congenital heart surgery is uncertain. The goal of this study was to compare brain structure changes and neurodevelopmental outcome in patients with severe congenital heart disease with and without intraoperative CD. METHODS: Neonates requiring congenital heart surgery were enrolled in a cohort study. NIRS data from their first cardiac operation were collected. Pre- and postoperative brain magnetic resonance imaging results and Bayley-III scores at 1 year were compared between patients with and without CD, defined by 2 NIRS thresholds: regional cerebral oxygen saturation (rSO2) of 45% (45%rSO2) and rSO2 below 20% of baseline value (20%BLrSO2). RESULTS: Thirty-two patients (72% male) with d-transposition of the great arteries (n = 24, 75%) and other complex types of congenital heart diseases (n = 8, 25%) were analysed. Perioperative relative lateral ventricle volume change was increased in patients with versus without intraoperative CD (P = 0.003 for 45%rSO2, P = 0.008 for 20%BLrSO2). For 45%rSO2, the effect of CD remained significant after adjusting for age at postoperative scan, time between scans and cardiac diagnosis (P = 0.019). New intracranial lesions occurred predominantly in CD groups (6/6 patients for 45%rSO2, 5/6 patients for 20%BLrSO2). Neurodevelopmental outcome at 1 year was not associated with intraoperative CD. CONCLUSIONS: This study demonstrates the clinical relevance of NIRS monitoring during congenital heart surgery. The occurrence of intraoperative CD is associated with perioperative lateral ventricle volume change and new intracranial lesions.

Role of sevoflurane in organ protection during cardiac surgery in children: a randomized controlled trial.

OBJECTIVES: The protective effects of volatile anaesthetics against ischaemia-reperfusion injury have been shown in vitro, but clinical studies have yielded variable results. We hypothesized that, in children, sevoflurane provides superior cardioprotection after cardiac surgery on cardiopulmonary bypass (CPB) compared with totally intravenous anaesthesia (TIVA). METHODS: In this randomized controlled, single-centre study, 60 children with cyanotic and acyanotic heart defects undergoing elective cardiac surgery under CPB (RACHS-1 1-3) were randomized to sevoflurane or TIVA (midazolam <6 months of age, propofol >6 months of age). The primary end-point was the postoperative peak cardiac troponin I/T (cTnI/T). Perioperative cardiac function (as determined by brain-type natriuretic peptide, echocardiography and postoperative vasopressor/inotrope requirements), short-term clinical outcomes (duration of intubation, intensive care unit and hospital length of stay), postoperative inflammatory profile, and pulmonary, renal and liver function were defined as secondary end-points. Analysis of variance was used for statistical analysis. RESULTS: There was no statistically significant difference in postoperative peak troponin values or any of the secondary end-points. In the subgroup of acyanotic patients under 6 months, sevoflurane led to significantly lower postoperative troponin levels compared with midazolam [reduction of 54% (95% confidence interval 29-71%, P = 0.002)], without any differences in secondary outcome parameters. CONCLUSIONS: Sevoflurane did not provide superior myocardial protection in our general paediatric cardiac surgical population. In children under 6 months, however, sevoflurane might be beneficial in comparison with midazolam. The conditioning effects of sevoflurane in specific paediatric subgroups need to be further investigated.

Two different hematocrit detection methods: different methods, different results?

BACKGROUND: Less is known about the influence of hematocrit detection methodology on transfusion triggers. Therefore, the aim of the present study was to compare two different hematocrit-assessing methods. In a total of 50 critically ill patients hematocrit was analyzed using (1) blood gas analyzer (ABLflex 800) and (2) the central laboratory method (ADVIA® 2120) and compared. FINDINGS: Bland-Altman analysis for repeated measurements showed a good correlation with a bias of +1.39% and 2 SD of +/- 3.12%. The 24%-hematocrit-group showed a correlation of r2 = 0.87. With a kappa of 0.56, 22.7% of the cases would have been transfused differently. In the-28%-hematocrit group with a similar correlation (r2 = 0.8) and a kappa of 0.58, 21% of the cases would have been transfused differently. CONCLUSIONS: Despite a good agreement between the two methods used to determine hematocrit in clinical routine, the calculated difference of 1.4% might substantially influence transfusion triggers depending on the employed method.