OR42: A Single Blinded Randomised Controlled Trial of Preoperative Oral Supplements in Weight Losing Patients with Colorectal Cancer

Preoperative nutrition therapy in people undergoing gastrointestinal surgery

BACKGROUND

Poor preoperative nutritional status has been consistently linked to an increase in postoperative complications and worse surgical outcomes. We updated a review first published in 2012.

OBJECTIVES

To assess the effects of preoperative nutritional therapy compared to usual care in people undergoing gastrointestinal surgery.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, three other databases and two trial registries on 28 March 2023. We searched reference lists of included studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of people undergoing gastrointestinal surgery and receiving preoperative nutritional therapy, including parenteral nutrition, enteral nutrition or oral nutrition supplements, compared to usual care. We only included nutritional therapy that contained macronutrients (protein, carbohydrate and fat) and micronutrients, and excluded studies that evaluated single nutrients. We included studies regardless of the nutritional status of participants, that is, well-nourished participants, participants at risk of malnutrition, or mixed populations. We excluded studies in people undergoing pancreatic and liver surgery. Our primary outcomes were non-infectious complications, infectious complications and length of hospital stay. Our secondary outcomes were nutritional aspects, quality of life, change in macronutrient intake, biochemical parameters, 30-day perioperative mortality and adverse effects.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodology. We assessed risk of bias using the RoB 1 tool and applied the GRADE criteria to assess the certainty of evidence.

MAIN RESULTS

We included 16 RCTs reporting 19 comparisons (2164 participants). Seven studies were new for this update. Participants' ages ranged from 21 to 79 years, and 62% were men. Three RCTs used parenteral nutrition, two used enteral nutrition, eight used immune-enhancing nutrition and six used standard oral nutrition supplements. All studies included mixed groups of well-nourished and malnourished participants; they used different methods to identify malnutrition and reported this in different ways. Not all the included studies were conducted within an Enhanced Recovery After Surgery (ERAS) programme, which is now current clinical practice in most hospitals undertaking GI surgery. We were concerned about risk of bias in all the studies and 14 studies were at high risk of bias due to lack of blinding. We are uncertain if parenteral nutrition has any effect on the number of participants who had a non-infectious complication (risk ratio (RR) 0.61, 95% confidence interval (CI) 0.36 to 1.02; 3 RCTs, 260 participants; very low-certainty evidence); infectious complication (RR 0.98, 95% CI 0.53 to 1.80; 3 RCTs, 260 participants; very low-certainty evidence) or length of hospital stay (mean difference (MD) 5.49 days, 95% CI 0.02 to 10.96; 2 RCTs, 135 participants; very low-certainty evidence). None of the enteral nutrition studies reported non-infectious complications as an outcome. The evidence is very uncertain about the effect of enteral nutrition on the number of participants with infectious complications after surgery (RR 0.90, 95% CI 0.59 to 1.38; 2 RCTs, 126 participants; very low-certainty evidence) or length of hospital stay (MD 5.10 days, 95% CI -1.03 to 11.23; 2 RCTs, 126 participants; very low-certainty evidence). Immune-enhancing nutrition compared to controls may result in little to no effect on the number of participants experiencing a non-infectious complication (RR 0.79, 95% CI 0.62 to 1.00; 8 RCTs, 1020 participants; low-certainty evidence), infectious complications (RR 0.74, 95% CI 0.53 to 1.04; 7 RCTs, 925 participants; low-certainty evidence) or length of hospital stay (MD -1.22 days, 95% CI -2.80 to 0.35; 6 RCTs, 688 participants; low-certainty evidence). Standard oral nutrition supplements may result in little to no effect on number of participants with a non-infectious complication (RR 0.90, 95% CI 0.67 to 1.20; 5 RCTs, 473 participants; low-certainty evidence) or the length of hospital stay (MD -0.65 days, 95% CI -2.33 to 1.03; 3 RCTs, 299 participants; low-certainty evidence). The evidence is very uncertain about the effect of oral nutrition supplements on the number of participants with an infectious complication (RR 0.88, 95% CI 0.60 to 1.27; 5 RCTs, 473 participants; very low-certainty evidence). Sensitivity analysis based on malnourished and weight-losing participants found oral nutrition supplements may result in a slight reduction in infections (RR 0.58, 95% CI 0.40 to 0.85; 2 RCTs, 184 participants). Studies reported some secondary outcomes, but not consistently. Complications associated with central venous catheters occurred in RCTs involving parenteral nutrition. Adverse events in the enteral nutrition, immune-enhancing nutrition and standard oral nutrition supplements RCTs included nausea, vomiting, diarrhoea and abdominal pain.

AUTHORS' CONCLUSIONS

We were unable to determine if parenteral nutrition, enteral nutrition, immune-enhancing nutrition or standard oral nutrition supplements have any effect on the clinical outcomes due to very low-certainty evidence. There is some evidence that standard oral nutrition supplements may have no effect on complications. Sensitivity analysis showed standard oral nutrition supplements probably reduced infections in weight-losing or malnourished participants. Further high-quality multicentre research considering the ERAS programme is required and further research in low- and middle-income countries is needed.

Associations between anthropometric indices and outcomes of congenital heart operations in infants and young children: An analysis of data from the Society of Thoracic Surgeons Database

BACKGROUND

Children with congenital heart disease are at risk for growth failure due to inadequate nutrient intake and increased metabolic demands. We examined the relationship between anthropometric indices of nutrition (height-for-age z-score [HAZ], weight-for-age z-score [WAZ], weight-for-height z-score [WHZ]) and outcomes in a large sample of children undergoing surgery for congenital heart disease.

METHODS

Patients in the Society of Thoracic Surgeons Congenital Heart Surgery Database having index cardiac surgery at age 1 month to 10 years were included. Indices were calculated by comparing patients' weight and height to population norms from the World Health Organization and Centers for Disease Control and Prevention. Outcomes included operative mortality, composite mortality or major complication, major postoperative infection, and postoperative length of stay. For each outcome and index, the adjusted odds ratio (aOR) (for mortality, composite outcome, and infection) and adjusted relative change in median (for postoperative length of stay) for a 1-unit decrease in index were estimated using mixed-effects logistic and log-linear regression models.

RESULTS

Every unit decrease in HAZ was associated with 1.40 aOR of mortality (95% CI 1.32-1.48), and every unit decrease in WAZ was associated with 1.33 aOR for mortality (95% CI 1.25-1.41). The relationship between WHZ and outcome was nonlinear, with aOR of mortality of 0.84 (95% CI 0.76-0.93) for 1-unit decrease when WHZ ≥ 0 and a nonsignificant association for WHZ < 0. Trends for other outcomes were similar. Overall, the incidence of low nutritional indices was similar for 1-ventricle and 2-ventricle patients. Children between the age of 1 month and 1 year and those with lesions associated with pulmonary overcirculation had the highest incidence of low nutritional indices.

CONCLUSIONS

Lower HAZ and WAZ, suggestive of malnutrition, are associated with increased mortality and other adverse outcomes after cardiac surgery in infants and young children. Higher WHZ over zero, suggestive of obesity, is also associated with adverse outcomes.