Ann. Medit. Burns Club - voL 6 - n. I - March 1993

THE INFLUENCE OF A VARIETY OF PARAMETERS ON THE OUTCOME OF THE BURN DISEASE IN ELDERLY PATIENTS

D'Arpa N., Napoli B., Masellis M.

Divisione di Chirurgia Plastica e Terapia delle Ustioni, Ospedole Civico, USL 58, Palermo, Italy

SUMMARY. A number of parameters (age, percentage burn, time interval between bum and initiation of resuscitatory therapy, bum phase, previous pathology, type of treatment) are analysed in relation to the outcome of the bum disease in patients aged 65 years or more. The analysis shows that deaths are generally due to the reciprocal influence of all the parameters considered.

We consider patient to be elderly if they are aged 65 years or over, as this is the age at which, in Italy, workers have to cease their activity and retire (10).
This investigation examines the influence of a variety of parameters (age, percentage burn, time interval between burn and initiation of treatment, burn phase, previous pathology, and medical or surgical treatment) on the outcome of the burn disease in elderly patients.
Our data are taken from a survey of the clinical files of patients admitted to the Division of Plastic Surgery and Bums Therapy at Palermo Civic Hospital between 1975 and 1992. During this period 257 burned patients aged 65 or over were admitted, of whom 151 were discharged as clinically well (66 males and 85 females) and the remaining 106 (55 males and 51 females) died.
Before proceeding to the analysis, it may be useful to consider the pathologies existing prior to the bum (Table 1). Although old age is a normal physiological event, it may also be a predisposing factor in the development of conditions leading to diseases that influence the outcome of the burn (2).

With regard to the effect of age on the outcome of the burn (Fig. 1), there was a progressive percentage increase in the number of deaths, and a corresponding decrease in the survival rate, as age increased.

Fig. 1 Outcome: Distribution according to age group

In patients aged over 84 years the. death rate (64.3%) was nearly double the survival rate (35.7%).

Considering the patients from the point of view of burned body surface (Fig. 2), we can see, as in- the case of age, an increase in the death rate as a function of increased burn extent; the death rate was 93.6% in patients with over 31% burns and 100% when burns exceeded 5 1 %.

Fig. 3 shows the number of deaths and discharges in relation to the time period between the burn and the beginning of resuscitatory treatment. As with the age and percentage burn parameters, the increase in the time period before the patients were admitted corresponded to an increase in the death rate.

Fig. 2 Outcome: Distribution according to % burn Fig. 3 outcome: Distribution according to time interval between burn and hospitalization

The number of discharges exceeded that of deaths when admission was less than 1 h after the trauma (60.8% and 39.2% respectively, out of 46 patients); the percentage of discharges was slightly less than that of deaths when admission was between 1 and 3 h after the trauma (48.8% and 51.2% respectively, out of 45 patients). The percentage of discharges dropped further when resuscitatory therapy was initiated between 3 and 6 h after the burn (38.7% and 61.3% respectively, out of 49 patients).
Admission occurring after longer periods shows more survivals than deaths. This apparently contradictory finding is due to the fact that these patients had been transferred from other hospitals where they had received early resuscitatory treatment, or else were patients with deep but not extensive burns.

Regarding death in relation to the burn phase (Table 2), 33 patients (31.2%) died during the emergency phase, i.e. within 48-72 h of the burn, 54 patients (50.9%) died in the acute period (i.e. from the 4th day of hospitalization until surgical therapy), and 19 patients (17.9%) died in the successive period (chronicization phase). We include in this last group patients who could not be subjected to the surgical treatment which they in fact required, owing to various severe complications.

Table 3 shows the influence of previous pathology in relation to the burn phase. The pathology was usually not stated in the case of patients arriving in severe conditions and living alone, and in rare cases was negative (i.e. the, patients were apparently healthy).
Multiple pathology (diseases involving two or more organs or systems, including without exception in our cases the cardiovascular system) and isolated cardiovascular pathology were the conditions most frequently present in elderly patients who died (43.5% and 22.8% respectively). A comparison between Table 3 and Table 1 shows that death occurred in 50.5% of patients with multiple pathology and 33.1% of patients with cardiovascular pathology. Four out of the 11 patients with respiratory pathology died (36.3%), 4 out of 8 with diabetes (50%), and 4 out of 7 with neuropsychiatric pathology (57.1%).

Fig. 4 shows the distribution of patients on the basis of the type of treatment given, in deceased patients and in patients who recovered. As can, be seen, out of the 151 discharged patients 58.9% were subjected to surgical therapy and 41.1% received only medical treatment. Among the deceased patients there was a marked prevalence in the number of nonsurgically treated patients (87.8%) over medically treated patients (12.2%).

Fig. 4 Outcome: Distribution according to type of treatment

Discussion

We have seen that out of the 257 elderly burn patients admitted 106 (41.3%) died and 151 (58.7%) were discharged as clinically well.
Other reviews of case histories also show a high death rate. Baux et al. (4) reported a death rate of 59% (22 out of 37 patients) among elderly patients (age 70 years or over) admitted over a 3-year period (1983-85).
Li Bing-guo et al. (6) reported 36 deaths (32.7%) out of a total of 110 elderly burn patients (age 65 years or over) admitted over a 10-year period (1978-88).
The above authors stress the important role of age in determining the high mortality rate, referring to factors such as limited physiological reserves, diminished defence mechanisms, and previous pathologies. In the elderly these factors significantly impair the capacity to overcome the shock, infection and metabolic disturbances that frequently occur in more extensive bums.

Age, associated with burn extent, is thus a critical factor. According to our data, and as confirmed by other data in the literature, the upper limit of the burned surface area for which the elderly burn patient has some expectation of survival is 30%. Hartford and Ziffren (11) report no cases of survival in elderly burn patient with burns in more than 30% of body area. In our survey, only 2 out of 31 patients with burns in 31 to 50% body surface area survived.

It is interesting to note that in both these cases the patients were aged 65-69 years, had unimportant pathologies (gastritis in one and arthropathy in the other), were admitted after a delay of no more than 3 hour, and were subjected to only one surgical operation.
The time interval between the burn and the initiation of therapy is another critical factor. The burn determines a loss of fluids which makes it necessary to administer other fluids intravenously in order to reintegrate the loss, prevent shock and maintain organic functions. The greatest loss of fluids from and in burned tissues is thought to occur in the first 18-24 hours, with its peak in the first 6-12 hours, starting immediately after the burn (3, 14). For infusion therapy to be effective, as well as adequate in quantity and quality, it must be initiated as soon as possible, and in the case of patients admitted late not actually receiving therapy it is essential to make up for lost time. Pruitt (14), in relation to resuscitatory fluid therapy in the burn patient, noted on the one hand the presence in most patients of a physiological reserve and effective compensatory mechanisms and, on the other, the existence of patients who appear to be refractory to resuscitation. In this latter category he included patients with massive burns (70% or more total body surface area), the elderly, and patients in whom resuscitatory therapy was delayed. If the early initiation of resuscitation is thus fundamental, it is even more vital in the case of elderly patients, whose response to resuscitation is very slow.
Our survey shows that delayed resuscitation affected early mortality and determined the causes of death. Nineteen out of the 33 patients (62.7%) who died in the emergency phase were adniitted, while receiving no therapy, 3 to 6 hours after the burn.
Table 4 shows the causes of death in the emergency phase. As can be seen, 69.7% of the deaths were due to shock and acute kidney failure secondary to unsuccessful resuscitatory treatment, which in most cases was delayed in starting. In addition to late initiation of resuscitatory therapy, other factors played an important role in early mortality, e.g. very advanced age and considerable burn extent. The mean age of patients in this group was 78 years and the mean burn extent 50%.
Advanced age, considerable burn extent and delayed resuscitatory therapy were also associated with a condition of previous disease. This last factor has a decisive role in non early mortality. Baxter (5) points out that the cardiovascular system is the system most affected by burns, and that, because of the overwork and the high cardiopathy rate in the elderly, serious cardiac complications are frequent in these patients.
In fact, we found that out of the 73 patients in our survey who died in the acute or chronicization phase 43 (59%) died of myocardiac infarction or sudden cardiac decompensation, while the remaining 30 (41%) died either of acute kidney failure (14 cases, 19.1%), bronchopneumonia (7 cases, 9.6%), severe respiratory failure (4 cases, 5.4), acute anaemia (3 cases, 4.1%) or septicaemia (2 cases, 2.7%).
Finally, as regards treatment, we found that 102 patients (39.6%) were subjected to surgical therapy. Of these 89 (87.2) were discharged as clinically well and the remaining 13 (12.8%) died.
Early surgery was not generally performed; as these patients are elderly we prefer to subject them to surgical operation after chemical escharectomy (with antibiotic salicylic vaseline) so that only one operation should be necessary (12, 13). According to this protocol, the elderly patient is operated on when second-degree burns have healed and third-degree zones have good granulation tissue ready for skingrafts. In our survey the elderly patients subjected to surgery were operated on after an average period of 17.9 days, and the average number of operations per patient was 1.2.
With regard to the patients who died, the average number of days of post-operative survival was 13.6 (range 1-41).
In 3 cases only (23%) the death of the patients on the first day may be presumed to be related to the surgical operation. The mean age of the 13 patients who died following surgery was 77.1 years and the mean burn extent was 22.8%; previous multiple pathology was present in 7 cases (53.8%) and cardiovascular pathology in 6 cases (46.2).

RESUME. Les auteurs analysent divers paramètres (l'âge, le pourcentage de la brûlure, le temps passé entre le moment de la brûlure et le commencement de la thérapie réanimatoire, la phase de la brûlure, la pathologie préexistante, le type de traitement) en fonction de l'issue de la maladie chez des patients âgés de 65 ans et de plus. Uanalyse montre que les décès sont généralement dus à l'influence réciproque de tous les paramètres considérés.

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