Annals of Burns and Fire Disasters - vol. XII - n° 3 - September 1999

ANTIBIOTIC SALICYLATE VASELINE: A TOPICAL TREATMENT OF CHOICE IN BURNED DIABETIC PATIENTS?

Napoli B, D'Arpa N, laia A, Sferrazza G, Masellis M.

Divisione di Chirurgia Plastica e Terapia delle Ustioni, Ospedale Civico, Palermo, Italy

SUMMARY. The healing of burns in diabetic patients is delayed by the vascular obstruction due to the disease and by the effects of diabetes (insufficient inflammatory response, insulin insufficiency and/or resistance). Local treatment is thus of fundamental importance for the healing of the wounds and for metabolic compensation, which is closely related to healing and which in turn it affects. In their clinical practice, the authors of this paper use antibiotic salicylate vaseline as their elected topical treatment of burns in diabetic patients in the light of the fact that antibiotic salicylate vaseline has a keratolytic and antimicrobial effect, improves local circulation, and increases the activity of insulin.

Introduction

Various researchers in the past have proposed the use of salicylate vaseline with various concentrations of salicylic acid and of antibiotic antiseptic salicylate vaseline (AASV) in the local treatment of burns.
In patients with localized burns in particular body areas (face, neck, flexor folds, perineal area), in whom surgical escharectomy is difficult to perform, or in bad physical condition (serious damage to upper airways, serious shock, previously generally poor physical condition, etc.), in whom early escharectomy would be dangerous both aesthetically and quoad vitam, the use of the proposed method permits good and rapid chemical escharectomy, without blood loss. It also improves the prospects of good skin-graft take.
Antiseptics and antibiotics were added to the salicylate vaseline in order to increase salicylic acid's antimicrobial effect.
It happens ever more increasingly that Burn patients are unaware of their diabetic condition, which therefore went untreated. This and other physiopathological and clinical considerations regarding diabetes prompted us to study more deeply this method's possible local and more general effects on diabetes. We were also interested in its influence on the healing of the damaged areas.
It is well known that wounds in diabetic patients are extremely slow-healing. This delay is due to the combination of two factors:

• disturbances in local blood circulation
• the effects of hyperglycaernia (insulin insufficiency or resistance)

The circulation disorders are a consequence of the vascular obstructive disease. This affects above all the peripheral vessels, with negative consequences for oxygen flow (hypoxia) and for the nutritional substances reaching the wounds (malnutrition).
The inflammatory response in diabetic patients is insufficient, and the consequences of insulin deficiency (blockage of anaerobic glycolysis, from which the white blood cells receive most of their energy) are associated with those of hyperglycaemia. This condition inhibits phagocytosis and therefore the intracellular lysis of bacteria ingested by wound macrophages. This is why diabetics are so liable to infection.
Another important factor involved in the slow healing of diabetic patients' wounds is the direct effects of insulin deficiency on the fibroblasts as regards glucose absorption and protein synthesis, both of which are considerably reduced.

Material and methods

The AASV used was prepared following the same criteria as that for non-diabetic individuals, i.e. on the basis of the findings of the antibiograrns performed on germs isolated from burn wounds in patients admitted in periods just before admission of these patients, until it becomes necessary to select patients on the basis of the sensitivity of the particular infecting germ isolated from the patients. The same applies to the choice of salicylic acid concentration (type of Burn, dry or wet, site, approximate estimate of degree).` It must not however be forgotten that in diabetic patients higher concentrations are more likely to lead to hypoglycaernia. The Burns treated were either partial- or full-thickness, in diabetics who were already on insulin treatment or began treatment after coming to us. Six patients (4 male, 2 female) were observed (age range 38-65 yr). The following parameters were assessed in each patient: time for elimination of eschar after initiation of treatment, amount of graft take, glycaemia monitoring, and the effect of treatment on the healing of untreated superficial burns.

Case histories

1. P.V., male, age 48 yr, admitted 5 June 1995 with partial- and fullthickness electric and flame burns, 30% BSA. Diabetes, of which the patient was unaware, was diagnosed after hospitalization. This required the administration of insulin. For local treatment we used AASV. The patient received a free skin graft on 22/6/95 in order to cover the residual burn areas, which were less than 5% BSA (Fig. 1).

   Fig. 1 - Burns distribution: operated areas indicated in black.

2. N.G., male, age 62 yr, admitted 2 September 1995 suffering from previously unsuspected diabetes. Presented sustained partial- and full-thickness flame burns in about 20% BSA. Third-degree circumferential Burns in left leg and thigh. Burns subjected to surgery on 18/9/95 after surgical escharectomy. On 28/9/95 there was no sign of infection and the grafts had taken perfectly.

3. A.G., male, age 59 yr. Patient unaware of preexisting disease. Suffering from partial- and full-thickness flame Burns in 20% BSA. Admitted 13 September 1995. Insulin therapy initiated after a few days, together with local treatment with AASV. The patient was subjected to skin grafting on 29/9/95 for the 3% residual burns that had not yet healed.

4. L.F., female, age 50 yr, suffering from flame burns in upper left limb. Admitted 9 October 1995. This diabetic patient was discharged completely cured on 31/10/95. The formation of good uninfected granulation tissue during the second week of local treatment with AASV was followed in the third week by total recovery. Demarcation and chemical escharectomy of necrotic tissue was performed in the first week.

5. C.G., female, age 57 yr, diabetic, admitted 16 January 1998 following explosion of gas cylinder. Partialthickness Burns in 65% BSA. Treated with salicylic vaseline. Deeper areas surgically cleansed on 28/01/98. This patient had a severe cardiopathic condition and died from cardiological complications on 5/2/98, when she had almost recovered from her local injuries.

6. S.M., male, age 38 yr, admitted 15 November 1998 for partial- and full-thickness flame burns in 10% BSA. Discharged fully recovered on 7/12/98. Also in this case monitoring of the deepest wounds showed that they healed in three weeks without any infective complications (Figs. 2-5).

   Fig. 2 - Partial-thickness burn and entire anterior thorax and neck. Fig. 3 - Same case. Partial -thickness burn and entire posterior thorax and neck. Fig. 4 - Same case. Healing after three weeks' treatment with antibiotic salicylate vaseline. Fig. 5 - Same case. Healing after three weeks' treatment with antibiotic salicylate vaseline.

Diabetes is a widespread disease. Those afflicted are however often unaware of their disease, which is not easy to manage, especially if complicated by burns.
The slow healing of the lesions is due to various mechanisms related to the basic diabetic condition and especially to the ease with which microbial infections affect diabetic patients. This delay has direct effects on the possibility of metabolic compensation.
The local treatment of burn wounds in diabetic patients is therefore of primary importance, not only as regards the healing of the burns but also as regards control of the diabetic condition. If the local treatment of burns in diabetic patients is to be effective, it is therefore necessary that it should influence the mechanisms that delay healing. Salicylate vaseline appears to possess these qualities.
Routine therapeutic doses of salicylates do not exert any important direct action on the cardiovascular system. High doses, however, cause the dilatation of peripheral vessels owing to the direct effect on the smooth musculature;' in diabetic patients they could therefore improve local circulation local circulation. By potentiating insulin and reducing its consumption, salicylates may be able to produce an excess of insulin at the level of the lesion. This would reduce glycaernia, improve the inflammatory response, and improve fibroblast activity.
For these reasons the use of salicylate vaseline would appear to considerably stimulate the formation of uninfected granulation tissue and subsequent reepithelialization. This occurs because its keratolytic and antimicrobial action would appear to be associated with the improved local circulation and the increase in insulin activity.

Even if the number of cases we treated was limited, our results enable us to hypothesize that antibiotic salicylate vaseline may be useful in the topical treatment of diabetic burn patients. In addition to its keratolytic and antimicrobial action, it influences the mechanisms that delay wound healing in diabetic patients. When used in the local treatment of lesions in diabetic patients, antibiotic salicylate vaseline promotes:

1. the healing of partial-thickness burns;
2. the healing of full-thickness burns of limited extent;
3. the reduction of the extent of widespread partialand full-thickness burns.