Effect of intravenous supplemental glutamine and clinical outcomes in burn patients receiving enteral nutrition

Abstract

The incidence of burn injuries is on the increase in Egypt due to migration to urban areas and the development of slum areas, but still there is a paucity of such data collection and organization. Burn injury, the most severe type of injury from a metabolic point of view, is characterised by the most profound alterations in basal metabolic rate. When the burn injury exceeds 15 to 20% of the total body surface area (TBSA), it results in systemic disturbances, including a major stress response, impaired immunity and extensive fluid redistribution. The metabolic response per se, as well as the increased physiological demands placed on the cardiac, pulmonary, renal and other organ systems, complicates nutritional support. Patients with major burn injuries also develop immune system impairment, which predisposes them to infection and multi-organ failure (MOF). These extensive metabolic alterations mitigate in favour of adequate nutritional support in order to meet the increased energy, protein, fat, carbohydrate and micronutrient requirements. Novel substances, such as glutamine, beside adequate nutritional support in burn patients can contribute for better outcome and recovery from burn injury. Nutritional support plays a key role in the recovery of critically ill burn patients. It is essential to ensure the restoration and improvement of general condition and immune status which are necessary to attain optimal patient function and survival post major tissue injury as in burn injury. The importance of nutritional support in critically ill burn patients is evident when knowing that malnutrition contributes in immune incompetence, poor wound healing, increased complications and prolonged hospital stay. The main goal of nutritional support is to minimize the catabolic response associated with any type of illness as those suffering from sepsis, burns, major trauma or those undergoing surgery and to treat malnutrition. An adequate evaluation of nutritional status usually can be accomplished with information from the medical history and physical examination, including simple anthropometric measurements, complemented by a few simple laboratory tests. Nutritional requirement includes adequate protein intake as well as calories in the form of glucose and fat. Minerals, trace elements and vitamins should be included in an ideal formula. The type of support needed is chosen according to the degree of metabolic alterations in stress burn response. The oral route is advised whenever possible and the patient is encouraged for early food intake. However, the enteral tube feeding may be needed to deliver adequate nutrients directly to the gastrointestinal tract. Enteral feeding importance arises from the fact that gastric mucosal integrity depends mainly on the presence of nutrients in the stomach. When selecting an enteral formula for a patient both the formula characteristics and the patient specific conditions and co-morbidities should be considered. Patients should be monitored frequently for adequacy of nutrient delivery and evidence of complications from enteral nutrition support. Complications of enteral nutrition include gastrointestinal, mechanical and metabolic complications. Refeeding syndrome is one of the metabolic complication which describe the adverse metabolic effects and clinical complications when a starved or seriously malnourished individual commences refeeding. Glutamine is the most abundant free amino acid. Glutamine appears critical for the integrity and function of gastrointestinal tract and immune system. Burn patients with TBSA % ranging from 20% to 50% commonly suffer from hyermetabolic state and depletion of endogenous glutamine stores with progressive decline in plasma glutamine concentrations which needs exogenous glutamine supplementation beside adequate nutritional delivery. As a result, glutamine supplementation in burned adults is found to improve glutamine levels in the body, promotes protein synthesis, improves wound healing and overall immune functions, improved gut intergrity and shortens overall hospital stay after burn injury with good clinical outcomes. The aim of our study is to assess the clinical outcomes and effects of intravenous glutamine supplementation in burn patients receiving enteral nutrition during their ICU stay. Our study was carried out on SIXTY critically ill burn Egyptian patients who were admitted to the Intensive Care burn Unit of Ain Shams University, thirty patients receiving L-alanyl L-glutamine dipeptide (Dipeptiven® Fresenius Kabi) and thirty patients, age matched not receiving the drug serving as the control group. Both groups received the same enteral feeding protocol and general management at the ICU. The patients (group A) and controls (group B) were subjected to full medical history, complete medical examination, APACHE II score on ICU admission, SOFA score on ICU admission and for follow up and laboratory investigations including nutritional biomarkers, inflammatory biomarkers, serum creatinine and ALT, nitrogen balance, and blood cultures. Also tolerance to enteral feeding, ICU stay and hospital stay were recorded. All of the above parameters were recorded to detect the difference between the 2 studied groups. The results of our study were statistically analyzed and we found that critically ill burn patients on enteral feeding and receiving supplementary parenteral L-alanyl L-glutamine dipeptide showed reduction in the incidence of infectious complications, mainly through a lower incidence of bacteremia and improved inflammatory biomarkers. Also there are improved nutritional biomarkers, a better metabolic and gastrointestinal tolerance to enteral feeding and improvement of nitrogen balance.