Metabolic response to surgery in infants and children.

Considerable advances have been achieved in paediatric surgery during the last two decades, which can be partly ascribed to a better understanding of the physiological response to operations and the use of that knowledge to decrease the metabolic response where appropriate. Alongside this, minimally invasive surgery is now well established for many surgical conditions in the neonate, infant and child. The metabolic response to surgery differs in neonates to that seen in adults: there is a small increase in oxygen consumption and resting energy expenditure immediately after surgery with a return to normal levels by 12-24 h. The increase in resting energy expenditure is significantly greater in infants undergoing a major operation than in those subjected to a minor procedure. The limited increase in energy expenditure may be due to diversion of energy from growth to tissue repair. There are limited data available on older children, but they appear to have a different pattern of postoperative resting energy expenditure. There is a fall in the early postoperative period, similar to data collected in adults, but no late hypermetabolism. Protein metabolism mirrors energy expenditure and contributes to the overall changes observed. Various factors affect the magnitude of the response. It seems that in children intraoperative thermoregulation and metabolism are significant drivers of many of the postoperative changes. Minimally invasive surgery may maintain preoperative metabolic processes by altering the postoperative processes on a physiological level or by maintaining thermoregulation in children. The mechanism and potential benefit of these observations need further investigation.

Decreased monocyte class II MHC expression following major abdominal surgery in children is related to operative stress.

Monocyte class II major histocompatibility complex (MHC) expression is necessary for antigen presentation and stimulation of T-cells. The aim of this study was to correlate monocyte class II MHC response to operative stress in children and the possible influence of cytokines in the postoperative period. We studied 21 children undergoing elective abdominal surgery. Operative stress score (OSS) was calculated. Monocyte class II MHC expression was measured preoperatively, immediately after surgery, 24 and 48 h postoperatively, using flow cytometry. Class II MHC is expressed as mean fluorescence intensity (MFI) of monocytes expressing MHC (mean +/- SD). Cytokine levels (interleukins 1ra, 6, and 10, and tumor necrosis factor-alpha) were also measured. Data between time points were compared using repeated measures ANOVA. There was an immediate postoperative decrease in class II MHC expression, with lowest levels 24 h postoperatively (preoperative 50 +/- 23.6, 24 h 18.2 +/- 9.4, P < 0.0001 vs. preoperative). At 48 h there was partial recovery in class II MHC, but levels were still significantly lower than preoperative (23.9 +/- 11.1, P < 0.001). The degree of monocyte depression was related to the magnitude of operative stress. Patients who had OSS <10 displayed some recovery in expression at 48 h 25.5 +/- 11.1), whereas in patients with OSS > or = 10 (severe surgical stress), expression further decreased at 48 h (MFI 14.0 +/- 0.1). There was an elevation of interleukin-1ra in the immediate postoperative period in both groups. There was no elevation in the other cytokines. Abdominal surgery in children decreases monocyte MHC expression. Class II MHC depression was related to magnitude of surgical trauma, implying that more severe immuneparesis follows surgery of greater magnitude. This may predispose to postoperative infection.

Laparoscopic surgery in children is associated with an intraoperative hypermetabolic response.

BACKGROUND: Laparoscopic surgery is thought to be associated with a reduced metabolic response compared to open surgery. Oxygen consumption (VO2) and energy metabolism during laparoscopic surgery have not been characterized in children. METHODS: We measured respiratory gas exchange intraoperatively in children undergoing 19 open and 20 laparoscopic procedures. Premature infants and patients with metabolic, renal, and cardiac abnormalities were excluded. Anesthesia was standardized. Unheated carbon dioxide was used for insufflation. VO2 was measured by indirect calorimetry. Core temperature was measured using an esophageal temperature probe. RESULTS: We found a steady increase in VO2 during laparoscopy. The increase in VO2 was more marked in younger children and was associated with a significant rise in core temperature. Open surgery was not associated with significant changes in core temperature or VO2. CONCLUSIONS: Laparoscopy in children is associated with an intraoperative hypermetabolic response characterized by increased oxygen consumption and core temperature. These changes are more marked in younger children.

Accuracy of antenatal fetal ultrasound in the diagnosis of duplex kidneys.

OBJECTIVES: To assess the accuracy of ultrasound diagnosis of duplex kidneys in the fetus and to identify prognostic features of antenatal sonography associated with this diagnosis. METHODS: Retrospective identification of cases with an antenatal diagnosis of duplex kidney was made from computerized databases. Results of postnatal radiological investigations were obtained from the unit where delivery took place. RESULTS: A total of 75% of cases seen in a multidisciplinary fetal renal clinic were correctly diagnosed as having a duplex kidney. Prognostic sonographic features are described. Detection of two separate poles or a ureterocele were strongly associated with a correct diagnosis. Accuracy was increased when two or more prognostic features were seen. CONCLUSION: Accurate sonographic diagnosis of duplex kidneys in the fetus is possible in a dedicated multidisciplinary setting. Antenatal counseling and planning of postnatal care for the infant can be made with a high degree of certainty.