Operation does not increase resting energy expenditure in the neonate

Is Energy Expenditure of Infants Predictable After Surgery?

Infants undergoing surgery have unique metabolic demands. The stress of an operation and recovery combined with expectations for growth and development imply elevations in energy expenditure beyond that of healthy, free-living infants. In contrast, surgery may trigger a diversion of energy utilization from tissue accumulation and growth toward the catabolic stress response and cytokine production. Predictive equations are commonly used in clinical settings to estimate basal or resting energy expenditure because measurement techniques such as indirect calorimetry may not be feasible or available. Investigations of measured energy expenditure in surgical infants have portrayed mixed results, however, and estimation equations may not consistently lead to accurate assessment of actual energy needs. Studies are limited in number and quality and often involve a heterogeneous, small population. Grouped outcomes may conceal the wide variability frequently observed in these studies. Measurement of energy expenditure is therefore preferable to the use of predictive equations to customize nutrition intervention for individual infants undergoing surgery.

Nutrition support in a surgical patient

Nutrition has very important role to play during health and disease state in human beings. Neonates and younger children are more prone to develop nutritional deficiencies. They have very critical reserves and are rapidly growing. Any surgical insult leads to multiple nutritional problems. Careful planning of nutritional management in a surgical patient is mandatory. Nutritional support should start from the day when the child develops the surgical condition to withstand stress of disease and surgical procedure. In the postoperative period nutritional support should start as early as possible. Start with small amount and build up gradually till the normal enteral nutrition (EN) is tolerated. When EN is not tolerated parenteral nutrition (PN) should be considered. Parenteral nutrition on short term basis is very important to tide over the crisis due to postoperative complications. Parenteral nutrition on long term basis is required in short bowel syndrome resulting from resection of large part of the gut. During PN, enteral nutrition should be continued in small amounts in order to maintain the integrity of mucosal lining of the gut. Enteral nutrition is more physiological and can provide adequate amount of immunonutrients, minerals and vitamins.

Metabolic response to neonatal surgery

The energy and protein metabolism of newborn infants differs from that of older individuals. Although energy expenditure and protein turnover are higher in newborn infants than in adults, the metabolic response to surgery in neonates has not been fully characterized. Preliminary studies indicate that metabolic response to operative stress is different in infants and adults: infants have an increased metabolic rate postoperatively for only 6 to 12 hours and do not have increased protein catabolism. More studies are needed in "stressed" newborn infants to further characterize substrate use and the metabolism of single organs.

Characteristics of protein and energy metabolism in neonates with necrotizing enterocolitis--a pilot study

BACKGROUND/PURPOSE

It is assumed that neonates with necrotizing enterocolitis (NEC) are hypermetabolic. However, the dynamics of protein and energy metabolism in neonates with NEC have not been characterized. The purpose of this study was to test the hypothesis that protein turnover and energy expenditure are increased during the acute stage of NEC and later return to normal values.

METHODS

A pilot study was performed on six neonates with proven NEC (Bell's stage II or III). Patients were studied in two phases: (1) in the acute stage of their disease and (2) when their clinical condition had stabilized. Whole-body protein turnover was calculated using an intravenous infusion of [1-13C] leucine and by measuring the isotopic enrichment of plasma [13C]alpha-ketoisocaproic acid and 13CO2. Respiratory gas exchange was measured simultaneously by computerized indirect calorimetry.

RESULTS

Median gestational age was 36 weeks (range, 28 to 40) with a median postnatal age of 21 days (range, 6 to 47). All patients recovered from the acute episode, although three patients died after recovering from the acute disease from other conditions. The patients studied showed marked variability in protein metabolism kinetics. However, there was no difference in whole-body protein flux between the acute phase (7.6 g/kg/d; range, 5.6 to 18.2) and the recovery phase (7.0 g/kg/d; range, 6.9 to 12.2; P = .89). Furthermore, there was no difference in any of the component parts of wholebody protein turnover. Resting energy expenditure did not change between the acute phase (42.8 kcal/kg/d; range, 34.4 to 52.5) and the recovery phase (51.0 kcal/kg/d; range, 34.9 to 55.3; P = .18).

CONCLUSIONS

This pilot study shows that the rates of protein and energy metabolism in neonates with NEC are comparable with reported values in stable neonates. There was no difference in protein or energy dynamics between study phases. The authors speculate that neonates with NEC may divert the products of protein synthesis from growth to tissue repair.

Effect of major abdominal operations on energy and protein metabolism in infants and children

PURPOSE

The authors attempted to test the hypothesis that infants and children increase whole-body protein flux and energy metabolism during the early postoperative period.

METHODS

Ten infants and children (age range, 2 days to 3 years; weight range, 1.5 to 14.2 kg) who had undergone a major operation were studied. Anaesthesia was standardised, and operative stress score (OSS) recorded. Patients were studied for 4 hours preoperatively and for the first 6 hours after surgery. Respiratory gas exchange was measured by computerised indirect calorimetry. The components of whole-body protein turnover were estimated by giving an intravenous infusion of [1-13C]leucine, and by measuring the isotopic enrichment of plasma [13C]alpha-ketoisocaproic acid by gas chromatograph mass spectrometry and 13CO2 enrichment by isotope ratio mass spectrometry.

RESULTS

Median duration of the operation was 73.5 minutes (range, 28 to 285 minutes) with a OSS of 8 (range, 7-17). There were no significant differences in oxygen consumption and resting energy expenditure between the two study phases. The respiratory quotient (RQ) fell from a preoperative value of 0.92 (range, 0.81 to 1.08) to 0.89 (range, 0.79 to 0.95) postoperatively (P = .04). The authors found no significant differences in the rates of whole body protein flux, protein synthesis, amino acid oxidation, and protein degradation between the study phases.

CONCLUSIONS

Infants and children do not increase their whole-body protein turnover and metabolic rate after major operations. The observed decrease in RQ reflects mobilisation of endogenous fat. We speculate that the lack of catabolism observed in children is caused by a diversion of protein synthesis from growth to tissue repair.

Evaluation of early enteral feeding in children less than 3 years old with smaller burns (8-25 per cent TBSA)

Early enteral feeding and high protein nutrition have been advocated for burned patients. The safety and efficacy of early high protein nasogastric feeding (NG) have not been evaluated in very young children. The present study evaluated such feeding in children less than 3 years old with smaller burns (8-25 per cent of total body surface area). Children (n = 10) were able to tolerate high protein intake without detrimental effects. The incidences of gastrointestinal complications related to NG feeding were low. The children needed approximately 2 weeks of supplemental NG feeding which provided two-thirds of total energy intake and three-fourths of protein intake. In spite of smaller burns, the mean measured resting metabolic expenditure (REE) was 1.3 x predicted REE. The mean energy intake of 92 per cent of recommended daily allowances (RDA) for energy or 1.7 x predicted REE was able to maintain body weight. The mean protein intake was 4.3 g/kg/day with a non-protein calorie ratio of 114:1. During the first week postburn, plasma concentrations of prealbumin, albumin and transferrin were low. The high protein intake was able to raise these visceral proteins to normal ranges. These results indicate that early NG feeding is safe and efficacious for achieving increased energy intake and improved protein status in very young children.

Nutrition considerations in the neonatal extracorporeal life support patient

Extracorporeal life support (ECLS) is a type of heart-lung bypass commonly used to support neonates with life-threatening respiratory or cardiac failure. These patients are among the most critically ill patients in the neonatal intensive care unit and are at significant nutritional risk. Unfortunately, there is a paucity of literature regarding guidelines for nutrition support of the neonatal ECLS patient. The purpose of this article is to provide an overview of the indications, techniques, and complications of ECLS and to address the approach to nutrition support of these patients. Emphasis will be placed on issues unique to the neonatal ECLS patient.

The metabolic response to operative stress in infants

The aim of this study was to characterize energy metabolism and substrate utilization in infants following an operation. Nineteen infants (weight 3.2 +/- 0.2 kg) who had an operation were studied. Anesthesia was standardized and operative stress score (OSS) was recorded. Five infants had a minor operation (OSS < 7), and 14 infants had a major operation (OSS > or = 7). Energy and nitrogen intake were constant during the 48-hour study period. Respiratory gas exchange was measured by indirect calorimetry preoperatively, and postoperatively for the first 12 hours continuously and at 24 hours, 48 hours, and 5 days. Urinary nitrogen excretion rate was measured for the first 48 hours following the operation. Physical activity was scored. Resting energy expenditure (REE) and nonprotein respiratory quotient (NPRQ) were calculated. REE increased postoperatively, peaking at 2 to 4 hours, and returned to baseline levels by 12 to 24 hours. Peak REE was significantly higher than baseline REE (P < .001). Substrate utilization was not altered by operation. The increase in REE was significantly greater in infants having a major operation than in infants having a minor operation (P < .05). Among infants having a major operation, the increase in REE was significantly greater in those infants more than 48 hours old, than in those infants less than 48 hours old (P < .05).(ABSTRACT TRUNCATED AT 250 WORDS)

Absence of hypermetabolism after operation in the newborn infant

This study was designed to assess the effect of operative stress on resting energy expenditure (REE) in the newborn infant. In 13 neonates who had an uncomplicated abdominal, thoracic, or spinal operation, REE was measured both preoperatively and on the third postoperative day. The mean preoperative REE of 43.19 +/- 7.95 kcal/kg per day was not significantly different from the mean postoperative REE of 41.70 +/- 7.94 kcal/kg per day. Sixteen neonates had REE measured on the first, second, and seventh postoperative days. The mean postoperative REE values of 43.12 +/- 6.92, 42.41 +/- 7.58, and 46.33 +/- 6.89 kcal/kg per day at 1, 2, and 7 days, respectively, were not significantly different from the preoperative REE. There was no significant difference in oxygen consumption, carbon dioxide production, and respiratory quotient between the preoperative and postoperative groups. In this study, an uncomplicated operation did not increase REE in the neonate.