Introduction

The activity of a burns unit in the management of the complex and continuous care required by burn patients is an objective example of the interdisciplinary approach to these problems. The burns surgeon, who has immediate responsibility for the patient, is the chief of the team. He or she has to co-ordinate the activity of all the other team members, e.g. the anaesthetist, the intemist, the microbiologist, the psychologist and the occupational therapist. One of the surgeon's most important co-workers is the internist - a specialist in the field of metabolism and nutrition. This is because, compared with other traumas, exten~ sive burn injury makes very high demands on energy requirements and is accompanied by significant specific changes in the fundamental nutrients, especially proteins. These changes are even more marked in the elderly, i.e. over 60 years of age. These patients very often present associated cardiac, pulmonary, renal and hormonal diseases, chronic dehydration, and even malnutrition. This paper reports our experience in the metabolic care of burn patients over the age of 60 years.

Material and methods

Sixty-two burn patients over the age of 60 years were treated at our Burns Unit during the five-year period 1991 - 95 (Table I). The average age was 72.8 yr; thirty-three were males (average age 72.4 yr) and twenty-nine females (average age 73.2 yr). The burned body surface area varied from 5 to 87% TBSA (average extent 21%). In all, seventeen patients died, ten males (average age 81.8 yr) and seven females (average age 81.7 yr). Metabolic and nutritional support was provided by a member of the "nutrition team" of the Department of Gerontology and Metabolism, who is also a regular member of the burn team. This physician ensures the clinical and laboratory monitoring of the patient's nutrition state and energy balance and individually prescribes and provides optimal nutrition, if necessary by perioral intake, enteral nutrition using tubes, parenterally, or in mutual combination.
In the treatment of burn injury in the elderly, we must bear in mind some of their typical characteristics. Some of these are handicaps, but others can be regarded as "advantages". The handicaps are multimorbidity and organism fragility, loss of muscular mass, slower healing, and a tendency to dehydration (tubular involvement of the kidney, reduced feeling of thirst), while the "advantages" for treatment are greater patience, better pain tolerance, and lower polysysternic anti-inflammatory reaction.
In the resuscitation and acute post-burn phase we used to initiate infusion therapy with crystalloid solutions (Hartmann solution or Ringer's lactate), just as with patients in other age groups. However, insufficient hydration is not an infrequent occurrence with this procedure and we therefore now we pay more attention to the rapidity and amount of fluid replacement. In older people there is a high risk of pulmonary oedema and cardiac insufficiency. The aim is to induce diuresis in the region of 3-4 1 per 24 h.

In the monitoring of hydration in elderly patients, we respect the principle "less invasive, more intensive". The parameters we follow are :

• central venous pressure and its dynamics during treatment
• diuresis, Na/K ratio in the urine, response to diuretics
• heart rate (there is a certain limitation at a relatively frequent atrial fibrillation)
• systemic blood pressure - hypertension is often used as the initial value in the patient's history
• oxygen saturation
• lactate blood level and dynamics during hydration

From the second day post-burn we administer sugar solutions and later also amino acids and fats.
As a rule we provide nutritional support in three ways:

1. Parenteral - in nearly all burn patients, especially in the first ten days, preferentially to a peripheral vein. Using "all-in-one" infusion-bags we supply:

   • energy (25-30 kcal/kg/day)
   • amino acids (1.24.5 g/kg/day)
   • sugar (150-200 g/day)
   • fats (50-100 g/day)

2. Enteral - we aim to start enteral nutritional support as soon as possible by means of a nasojejunal tube (diameter 2 mm). The tube is inserted and a skiascopic check of its position is carried out. It is also possible to insert an enteral tube in addition to the gastric tube: this application controls nutrition tolerance.

3. Perioral diet + protein additions = sipping. There are some important limitations on nutrient intake. To respect these limitations we follow a two-step procedure, as follows :
   • sugars: glycaerma higher than 10 mmol/l
     Step 1: reduce sugar intake to 150-200 g
     Step 2: continuous insulin (by pump)
   • fats: at triacylglycerol serum level over 4 mmol/I the dose is reduced to the amount that is tolerated
   • amino acids: increase in blood urea nitrogen
     Step 1: increase in fluid turnover
     Step 2: dose reduction to I g/kg/day
   • energy: ALT increase over 4 ukal/I
   • reduce energy
   • change nutrition composition

RESUME: Les soins complexes et continus aux patients brûlés représentent un exemple de l'approche interdisciplinaire à ces patients. Ce type de traumatisme présente beaucoup d'aspects spécifiques, particulièrement chez les patients âgés. Les Auteurs décrivent leur procédure thérapeutique et leur expérience avec le soutien métabolique et nutritionnel des patients âgés brûlés. Ils ont traité 62 patients âgés de plus de 60 ans (moyen 72,4) pendant la période 1991-95. La surface brûlée moyenne était 21% et la mortalité 25.7%. Les Auteurs décrivent les problèmes particuliers des patients âgés brûlés et aussi leurs "avantages". Pour la nutrition parentérale avec l'emploi des sacs "tout compris" ils fournissent: énergie 25-30 kcal/kg/24 h, aminoacides 1,2-1,5 g/kg/24 h, sucre 150-200 g/24 h, graisses 50-100 g/24 h.