Annals of the MBC - vol. 5 - n' I - March 1992

COMPARATIVE STUDY OF BURN PATIENTS AFTER TREATMENT WITH MORE AGGRESSIVE SURGICAL TECHNIOUES IN WOUND CARE

Luengo Matos S., Herruzo Cabrera R., Garcia Torres V., Fernandez Arjona M., Rey Calero J.

Departamento de Medicina Preventiva de UAM y Unidad de Quemados de HRT, La Paz, Madrid, España

SUMMARY. All 1367 patients admitted to a Bums Centre during the period 1971-1986 were considered retrospectively on the basis of the treatment administered in two sub-periods, before and after January 1982, when modifications in therapy were introduced (more aggressive surgery, more antibiotic prophylaxis, more parenteral feeding, different topical treatment). The comparison between the results showed better evolution of the bum disease in the second sub-period, as measured by a number of parameters.

Introduction
Burns are still today a very important problem, being one of the most frequent causes of death after traffic accidents (1).
Today the treatment in a Burn Unit has proved its efficacy (2).
The new analgesics and topical antibiotics, discoveries in the knowledge of human physiology and modern surgical techniques, together with the appropriate personnel in Burn Units, are the very important tools that have improved burn patient treatment (3, 4).
Nowadays one of the most important aims is to achieve early surgical debridement and early burn cover with skin graft. Using these aggressive surgical techniques, we obtain a better patient evolution, a decrease in infection and hospitalization time, and an increase in patient survival (5, 6, 7, 8, 9).
This paper attempts to assess whether or not the evolution of our burn patients has changed since we introduced these new surgical techniques for wound treatment in our Bum Unit.
We consider the main burn gravity factors capable of modifying the evolution of the patients; we also consider other treatments we introduced in our Unit to improve the care of burn patients.

Material and methods
We selected, retrospectively, 1367 patients admitted to the Critical Ward of the Bum Unit of La Paz Medical Center over a 15-year period (from 1971 to 1986). These patients exemplify all the patients admitted to this Unit during these years and represent 50% of the total patients. All patient data were recorded in one protocol.
This special protocol reports the evolution of the patient during hospitalization and the characteristics of the patients on admission.
We used this protocol with the 1367 patients in the study. The patients were split into two periods (patients admitted from January 1971 to December 1981, and patients admitted from January 1982 to December 1986). After 1982 we began to use more aggressive surgical techniques such as:

• early surgical debridement
• early burn cover.

In the last years of the second period, we introduced other improvements in general patient care, such as:

• antibiotic prophylaxis
• better topical treatment
• increased parenteral feeding.

We recorded 17 variables, grouped into three series:

1. Epidemiologic characteristics (this is important because it enabled us to compare the gravity of the patients in both periods):

• Sex
• age burn depth
• body area burned
• burn localization
• other associated injuries
• previous pathology

2. Treatment variables:

• days until first debridement
• days until complete debridement
• days until first skin graft cover
• days until complete cover
• number of skin grafts
• topical treatment
• parenteral feeding
• antibiotic prophylaxis

3. Evolution of patient variables:

• main complication after burn
• functional consequences of burn
• death
• length of hospitalization.

We used average and percentage comparison in order to discover differences between the two periods.

Results
Patients in the second period had higher age and body area burned than in the first (37.2 years vs 32.1 years and 13.4% vs 11.9%, respectively).
The numbers of subdermic lesions were higher in the second period than in the first (26.8% vs 17.5%). There was no statistical difference regarding sex (Tables 1 and 11). We did not find any differences from the other epidemiologic characteristics, except trachcobronchial damage (4.8% vs 12.9%) (Tables Ill, IV and V).
We also improved our treatment, using new methods, and we reduced the number of days until complete debridement of the wound, until the first skin graft cover and until the complete cover of the burn (Table V1); the number of skin grafts increased in the second period (Table VII). The improvements in topical treatments can be seen in Table VIII. We obtained an increase in the use of silver sulphadiazine or excipient, and a decrease in the use o nitrofurazone in the second period. The number of patients with antibiotic prophylaxis and parenteral feeding was higher in the second period (Tables IX and X).
Renal and infectious complications fell in the second period (8% vs 1.2% and 27.6% vs 15.8%, respectively); other complications did not change (Table Xl).
Unimportant functional consequences increased in the second period, and grave ones decreased (8.8% vs 5.5%); unimportant and grave psychic consequences decreased (9.4% vs 14.3% and 2.9% vs 1.3% respectively) (Table XII).
The number of patients who died was lower in the second period (7% vs 6.1%) (Table XIll). Hospitalization time also decreased in the second period (27.2 days vs 23.5 days).

Discussion
If we consider the three major factors of burn danger (age, body area burned and burn depth) we can see that patients in the second period are in more danger than those in the first period. Regarding age, however, we must consider that our Unit currently admits only adults. Thus in the first period we admitted 13% patients under 10 years old, against 3.5% in the second period; some authors think that burned children are more problematic than adults (10).
There is no significant difference between the two periods regarding the other epidemiologic characteristics, 6xcept in tracheobronchial damage, which increased significantly in the second period, possibly because we improved the discriminatory diagnosis of inhalation syndrome in the last years (11).
In line with the latest tendency favouring the advantages of rapid debridement and early cover, we introduced this proced0re in our Burn Unit. This caused an important decrease in the "complete cover time" (9). During 1986-1987 Garcia Torres (12) found in our Unit: 3.3 days until the first debridement, 6 days until complete debridement, and 13.6 days until complete cover of the bum; this shows important changes in this respect, and that we are maintaining the decreasing tendency.
We used silver sulphadiazine in the second period and nitrofurazone in the first; both products are considered today elective treatment (13), although the first is active against Gram positive and Gram negative, while the second is active only against Gram positive (12).
Antibiotic prophylaxis increased in the second period. Nowadays nobody systematically uses antibiotic parenteral prophylaxis, which is used only in well-documented infections (14).
In the last years of the second period we introduced two new techniques, which have proved their efficacy. These are:

• intestinal selective decolonization (15)
• prophylaxis before surgery (15, 16).

We have also increased the number of patients with parenteral feeding in an attempt to avoid the effects of catabolism of the burn, but for this purpose oral hyper-feeding is better if possible (17).
We found that renal and infectious complications were lower in the second period.
There is a relationship between the reduction of infections and early debridement and covering of the burn (18), but we think that other factors, such as antibacterial topical treatment, parenteral antibiotic prophylaxis and improvements in general care, may be associated with the decrease in the number of infections (19, 20).
We also found an association between the use of this aggressive technique and the reduction in the number of functional consequences, as in other authors (2 1).
Thompkins et al. (8) reported a reduction in hospitalization time (32 days to 22 days) when they began to use this technique; we obtained a sifnilar reduction, as in other authors (8).
Currery et al. did not1find a relationship between the use of this technique and patient survival, as they selected the patients who had a low death risk for their surgical procedures (1, 22).
We think that this relationship exists, and our patients had a higher survival when we used this aggressive technique. Some authors do not agree with usJl).
Thompkins et al. (8) say that the best results in patient survival using early self skin graft are obtained with old people, but as we did not have sufficient deaths we could not investigate this possibility.
Thompkins et al. (8) also noted that with regard to patient survival it is difficult to separate the effect of aggressive surgical treatment from other improvements, such as:

• immunology situation of the patient
• advances in metabolic care
• advantages in monitorization and respiratory support better nutrition and general care.

Finally, our patients had a better evolution after we used the new surgical treatments, but we think it is necessary to perform new epidemiologic studies in order to ascertain the real effects of this treatment. Clark et al. (23) say that it is necessary to develop a "burn gravity index" to be able to assess the efficacy of the different cares for burn patients.