Annals of Burns and Fire Disasters - vol. XII - n. 1 - March 1999

THE EFFECT OF EARLY TUBE FEEDING ON SERUM COPPER AND ZINC LEVEL IN BURNED CHILDREN

Gúmús N., Dalay C., Arsian E., Uslular S., Kivanc K.

Burn Unit of Plastic and Reconstructive Surgery Department, Medical Faculty of Cukurova University, Adana, Turkey

SUMMARY. Copper (Cu) and zinc (Zn) play an important role in biological and metabolic processes. These elements are essential to man and have a beneficial effect on wound healing that is important in burn patients. This study was designed to investigate the effect of early tube nutrition on serum Zii and Cu levels after the administration of Zn- and Cu-containing nutrition solutions. The study included 11 paediatric patients admitted within the first 30 h post-burn. The burns were either deep partial- or full-thickness and the extent varied from 12 to 35%. A commercial feeding solution containing 1 ing Cu and 12 mg Zn per 1 was given at a rate of 10 ml/h via nasogastric or nasoenteral tube by a pump continuously at the beginning and adding 10 ml per h. The daily caloric intake was calculated with the Davies formula. Nutritional support was continued for 17 days post-burn. Samples of venous blood were taken and analysed. A statistical comparison (Anova test) between the control and therapy groups showed significant differences. The differences between the first samples and the others were analysed by the Anova test but no significant difference was observed. It was found that commercial nutritional solutions do not include sufficient amounts of Zn and Cii to satisfy the requirements of paediatric patients. Supplementary amounts must therefore be added.

Copper (Cu) and zinc (Zn) play an important role in biological and metabolic processes. These trace elements are essential to man and have a beneficial effect on wound healing that is important in burn patients. Cu and Zn are necessary for the functioning of a number of clinically important biological enzymes, and the activity of these zinc-copper dependent enzymes is altered in particular conditions of tissue destruction and repair. Deficiencies of one or more trace elements can cause various diseases by affecting physiological and cellular functions. These micronutrients may also affect the cardiovascular and immune systems.
Serum levels of Zit and Cu have been shown to be reduced after burn injury owing to increased concentration in urine and exudate from the burn wound.` Some resuscitation fluids, alburnin solutions, and blood and its products include Cu, Zn and other trace elements. The use of these medications is ineffective to protect the serum and tissue levels in burn patients. Total parenteral nutrition solutions contain trace amounts of these elements but do not replace decreased trace elements in the serum of burn patients without the addition of trace elements. Oral nutritional support may be preferred because of the effect on the digestive system.
Oral nutrition can be administered after defecation in burned children in order to provide clinical nutritional support. Feeding that is initiated within 48-72 h post-burn may be defined as "early nutritional support' . A commercial nutrition solution containing a greater amount of Cu. and Zn than other solutions was selected and a study was designed to investigate the effect of early tube nutrition on the levels of serum Zit and Cu after the administration of Zn- and Cu-supplemented nutrition solutions.

This study included 11 paediatric patients admitted within the first 30 h after burn injury to the Burn Unit at Plastic and Reconstructive Surgery Department of the Medical Faculty at ~-'ukurova University in Turkey. The study was performed between 1996 and 1997, with five male and six female patients. The mean age was 5.9 yr (range, 2-15 yr). The burns ranged from 12 to 35% TBSA, and were either deep partial or full thickness. The mean total burned surface area was 21.7%. There were five patients with flame burns and six with hot water scalds.
Patients were admitted in the first 4 to 30 h postburn (mean post-burn admission time, 14 h). Fluid resuscitation was started according to the Parkland formula. None of the patients was given colloid solutions in the first 24 h. An enteral feeding tube (size 6 to 10 [French]) was inserted through the nares into the stomach or intestines and controlled by x-ray film after admission. A commercial feeding solution containing 1 tug Cu and 12 ing Zn per 1 was given at a rate of 10 mil/h via nasogastric or nasoenteral tube by pump, continuously at first and with 10 ml/h per h added. Nutritional support was continued for 17 days post-burn. Daily total caloric requirements were calculated with the Davies formula (60 kcal/kg/day + 35 kcal/%/TBSA/day). The feeding solution contained 1 keal/ml energy, 1 mg/1 Cu and 12 ing/1 Zir (Table I). The mean intakes of calories, Zii and Cii in the 24 h post-burn were respectively 772 kcal, 9.27 Ing and 0.77 mg (Table H). One, three, seven, ten, fourteen and seventeen days after admission samples of venous blood were taken and analysed by flame atomic absorption spectrophotometry. Venous blood samples from 40 healthy children were taken to check Zii and Cu serum levels. The Anova test was used for the statistical analysis of the results (Table III).

In this study, serum Cu and Zn levels were determined on six occasions in 11 children. Within 24 It of injury, a mean dose of Zn and Cu (9.27 and 0.77 mg, respectively) was being administered continuously via tube feeding by means of a nutrition pump (range for Zn, 7.08 to 14.4; for Cu, 0.59 to 1.2). On the following days the mean copper and zinc intakes were respectively 1.9 (range, 1.2-3.5) and 22.8 (range 14.4-42.0) mg. No patient received additional Cu or Zn supplementation during the study period of 17 days in response to serum Zn or Cu results. The mean Cu and Zn levels were found to be 99.12 ± 10.91 and 86.25 ± 12.94 pg/dl in the control group (Figs. 1, 2). A statistical comparison between control and the therapy group on different days showed a significant difference (p > 0.05). When the differences between the first samples and the others were analysed, no significant differences were observed (p < 0.05).

The choice of type of nutrition type depends on each patient's individual needs, physical characteristics, and the type and duration of the burn injury. In seriously burned patients, there is a tendency towards hypercatabolism, especially if nutrition is not initiated within the first 24 h post-burn. The administration of nutritional substrates in the first few days postburn protects the digestive system, counteracts infection, and prevents malnutrition by slowing down hypercatabolism.` If enteral nutrition is carefully planned and properly managed, the typical septic complications of parenteral nutrition therapy do not occur. Post-burn hypozincaemia and hypocupraemia have been well described. Although serum Zn and Cit concentrations tend to fall, urine excretion increases and minerals are thus lost from the body.
Berger et al.'studied the influence of large intakes of trace elements on serum levels in major burns. They showed that after daily administration of 4.5 ing Cri and 40.0 mg Zn, Cu and Zit status were improved in adult burn patients. In our study, the administration of 1 mg Cit and 22.8 mg Zn did not improve serum levels compared with control values. Both Zn and Cu decreased in all the samples. This lower serum level may be related to differences in metabolism or other requirements in children. The different results may be related to the administration of lower dosages. Bottschlich and Warden recommended 100 ing zinc daily for burned children under 3 years of age and 220 ing daily for those aged over 3 years.
Gosling et al.' observed that although the mean daily Cu and Zn intakes were respectively 4.2 and 19.7 ing (respective ranges, 1.7 to 10.8 and 9 to 39), hypocupraemia and hypozincaemia were found. Serum copper concentration was inversely correlated with the burn surface area and hypozincaemia was found in adult patients irrespective of the burn surface area. During our study, despite the fact that mean quantities of 1.9 ing Cu and 22.8 mg Zn were administered 24 h post burn, and nutritional support - including trace elements - was initiated in the first 24 h post-burn period, hypozincaemia and hypocupraemia were nevertheless observed.
In this study, it was observed that commercial nutritional solutions do not include sufficient amounts of Zn and Cit to satisfy the requirements of paediatric patients. Supplementary quantities of these elements have to be added. Paediatric burn patients need to be supported with greater amounts of trace elements than patients with other injuries. Further research is required to establish the quantities required for the restoration of decreased Zn and Cit serum levels.

RESUME. Le cuivre (Cu) et le zinc (Zn) jouent un rôle important dans les processus biologique et métabolique. Ces éléments sont essentiels pour l'homme et ils exercent un important effect positif sur la guérison des lésions des patients brûlés. Cette étude a considéré l'effet de la nutrition précoce nasogastrique et nasoentérale sur les niveaux sériques de Zn et de Cu après l'administration de Zn et de Cu qui contenaient des solutions nutritives. L'étude comprenait 11 patients pédiatriques hospitalisés dans les premières 30 après la brûlure. Nous avons administré une solution nutritive commerciale contenant 1 mg Cu et 12 mg Zn par litre dans la mesure de 10 ml/h moyennant tube nasogastrique ou tube nasoentéral avec l'emploi d'une pompe, continûment d'abord et augmenté dans la mesure de 10 ml/h par heure. L'apport journalier de calories a été calculé avec la formule de Davies. Le support nutritif continuait pour 17 jours après la brûlure. Des prélèvements de sang veineux ont été analysés et une recherche statistique (test Anova) entre les témoins et le groupe traité a démontré des différences significatives. Les différences entre les premiers prélèvements et les autres ont été analysées moyennant le test Anova sans trouver aucune différence significative. Les Auteurs ont observé que les solutions nutritives commerciales ne contiennent pas une quantité suffisante de Zn et de Cu pour satisfaire les besoins alimentaires des patients pédiatriques. Pour cette raison il faut que ces éléments soient administrés en quantité adéquate.

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