Prevention of bacterial growth and local infection in burn wounds

Prevention of Bacterial Growth and Local Infection in Burn Wounds By Laurence M. Linkner, Daniel T. Cloud, David S. Trump, and George W. Dorman

I

NFECTION HAS BEEN DESCRIBED as “the cardinal problem in the treatment of burns.. . [causing] conversion of Y’ burns to 3’ burns,“’ and as creating the “greatest threat to survival.‘12 Fatal septicemia resulting from local infection can best be avoided by preventing development of the infection. Because of the avascular condition of the would, control of infection generally requires topical antiseptic treatment.* In our pediatric surgical practice we have treated many burn patients and have used a variety of topical antiseptics with both the open and closed techniques, prior to developing a routine procedure acceptable to the two general hospitals in the area. On the basis of experience and clinical judgment, we now prefer povidone-iodine (Betadine Solution and Betadine Aerosol Spray)* wtih an open technique for the prevention of local infection. This paper examines a decade of accumulated data in an effort to evaluate objectively the validity of our clinical judgment. MATERIAL AND METHODS Treatment Population

The records of the 129 children who receiv&i topical antiseptic treatment for bums of at least second-degree severity in the past decade at Good Samaritan and St. Joseph’s Hospitals in Phoenix were analyzed. Antiseptic preparations employed were povidoneiodine, silver nitrate, mafenide, neomycin ointment, and nitrofurazone. Where more than one antiseptic was used serially in the same patient, each such use was evaluated separately. There were thus 156 evaluations in the 129 children. The study population, in terms of treatments, is described in Table 1.

Current Routine Procedure On admission the patient is evaluated and, if indicated, a tracheostomy performed. A Levine tube is inserted, a suitable vein cannulated for fluid-replacement therapy, and the bladder catheterized where needed for recording urine volumes hourly. The patient is weighed and blood samples obtained for cross-matching, hematocrit, hemoglobin, complete blood count, and base-line electrolyte determinations. Except for the cross-matching, this From the Pediatric

Services,

Good

Samaritan

and St. Joseph’s

Hospitnfs,

Phoenix,

Ariz.

Laurence M. Linkner, M.D.: Peditaric Services, Active Stati, Good Samaritan and St. Joseph’s Hospitals, Phoenix, Ariz. Daniel T. Cloud, M.D.: Pediatric Semites, Active Staff, Good Samaritan and St. Joseph’s Hospitafs, Phoenix, Ariz. David S. Trump, M.D.: Pediatric Services, Active Staff, Good Samaritan and St. Tosepk’s Hospitals, Phoenix, Ark George W. Dorman, M.D.: Pediatric Services, Associate Stati, Good Samaritan and St. Josepk’s

Hospitals,

Phoenix,

A&

*BetadIne Solution contains 10% povidone-iodine (yielding 1% available iodine) and Betadine Aerosol Spray contains 5% pocidone-iodine (yielding 0.50/o available iodine), The Purdue Frederick Co., Yonkers, N.Y. 310

Journal of Pediatric Surgery, Vol. 7, No. 3 (June-July), 1972

PREVENTION

OF INFECTION

311

IN BURN WOUNDS

Table 1. Treatment

Demography Number

Parameter

156 101 55

Total treatments: Males Females Age groups: 3 mo-1 yr 2-4yr 5-9 yr 10-19 yr Degree of burn: Second Second and third Per cent of surface area burned’:

1-19 20 or more *In adults a burn area of less than demarcation point is 200/o.’

Percentage

65

35

53 40 26 35

34

62 94

37 63

65 71

54 46

30% is usually well tolerated,

26 18 22

but in children

the

laboratory work is routinely repeated within 36-48 hr. Systemic antibiotic therapy, formerly with penicillin and streptomycin but more recently with penicillin alone, is administered for 5 days. The burn wound and surrounding area are cleaned with an antiseptic agent, most often Betadine Solution, and debrided. The povidone-iodine solution is applied to the burn and surrounding area-by “dabbing” with a sterile swab, or as a wet soak, or as a spray-every 2 hr for as long as practical or until healing starts. After this, the application varies rom eery 8 hr to once daily throughout the patient’s hospital stay, depending on the severity of the wound and degree of healing. With the open method, sheets are changed every 8 hr. Attending personnel are properly gowned and gloved as well as masked to reduce the incidence of cross-infection. In addition to specific antiseptic treatment of the burn wound, a total body bath using the povidone-iodine solution in low concentration is administered at least once daily. The bath includes hair shampooing with povidone-iodine for degerming purposes. Bacteriological cultures of the wound are routinely taken prior to grafting. Patients treated earlier in our experience were usually given antiseptic baths with a hexachlorophene soap; these were discontinued when pseudomonas organisms were cultured from the soap. RESULTS

and compared on the basis of (1) incidence of positive cultures generally, (2) incidence of pseudomonas growth, (3) incidence of septicemia, (4) length of hospital stay and (5) mortality. Since povidone-iodine with the open technique was not used exclusively until recently, this regimen was followed in 20 patients only. In addition to comparing our povidone-iodine experience with other treatments, overall and separately, an attempt was made to compare the open technique with the closed technique, regardless of agent employed. There was virtually no experience with the use of povidone-iodine and the closed technique. Treatments

were

evaluated

Betadine Solution and Aerosol Spray vs. Other Theatments the

Demagraphic and etiological parameters for the 30 treatment trials povidone-iodine preparations and the 126 other trials demonstrated

with no

312

LINKER ET AL. Table 2. Providone-Iodine

vs. Other Regimens Providone-Iodine Treatment (30), %

All Other Regimens (126), %

Twenty per cent or more of surface area burned

67 40

Incidence: positive cultures Incidence: pseudomonas growth Incidence: septicemia Hospitalized 31 days or more

20 0 0 23

59 47 21 10 3 31

Treatments

with third-degree

burns

statistically significant differences. (All statistical analyses were performed using the chi-square test of significance, with Yates correction for frequencies less than 10.)The proportion of second-to third-degree burns was somewhat larger in the povidone-iodine group, and the proportion of 20% or more of burn surface areas was somewhat larger in the non-povidone-iodine group (Table 2). The incidence of positive cultures was similar in both groups; incidence of pseudomonas growth, septicemia, and short hospital stay was lower in the povidone-iodine group than in the non-povidone-iodine group. Comparison of antiseptic agents individually suggests that the results with povidone-iodine and silver nitrate were roughly similar and somewhat better, particularly in the decisive parameters, than with the other agents studied (Table 3). Both inhibited pseudomonas growth and patients treated with both agents were free of septicemia; percentages with third-degree body burns were about the same. The incidence of positive cultures was lower in the silver nitrate group than in the povidone-iodine group, but the difference was not significant and both were well below the incidence with the other agents tested. Hospitalization was of briefer duration in the povidone-iodine group, but the incidence of 20% or more burn areas was smaller in this group. In addition to silver nitrate, mafenide is widely recognized as a topical antiseptic of choice in burns. In our institutions, however, reports of pain on application and relatively poor results limited its use. Because of the few cases involved, the comparison between this agent and povidone-iodine cannot be considered significant. Table 3. Results by Individual Agents ProvidoneIodine

Mafenide

Neomycin Compound

Nitrofurazon

AgNoa

Number of trials

30

5

53

34

34

Percent with third-degree body burn

67

60

62

44

66

Percentage with 20% more surface burn area Incidence of culture growth Incidence of pseudomonas growth Incidence of septicemia Percentage hospitalized 31 days

40 20 0 0 23

60 80 40 20 40

36 30 19 7 28

50 29 12 0 26

59 12 0 0 38

or longer Per cent significant

Number of deaths

mortality risk

17(5) 0

0 0

13(7) 2

6(2) 0

12(4) 0

PREVENTION OF INFECTION IN BURN WOUNDS

Open Technique

313

vs. Closed Dressing

Of the 156 trials studied, 97 were treated with either closed dressings or the open technique, and 59 with both. The 54 patients with closed dressings alone were more severely burned, and had a higher proportion of large burn areas than the 43 patients treated with the open technique. Hence, although precluded significant comparison. Mortality Two deaths occurred among the 129 children under study. Both were receiving neomycin compound for topical antisepsis at the time of death, with septicemia established as the cause of death in one of them. Using the National Burn Institute Exchange Mortality Analysis Charts5 (based on age and percentage of body burn), the expected mortality rate was calculated to be 17% (five deaths) for the povidone-iodine group (Table 3); it was 12% (four deaths) for silver nitrate. COMMENT

Although our experience with the povidone-iodine regime to date has not been sufficient for definitive conclusion, it suggests that the product is an effective topical antiseptic agent for control of microbial growth in burns. Its antimicrobial efficacy appears comparable to that of silver nitrate and rather better than that of other preparations employed by us during the decade of experience under study. If wider experience confirms the comparability of povidone-iodine with silver nitrate, it should prove to be an important addition to topical antiseptic therapy in burns since it avoids the well-known hazard of electrolyte loss, as well as the staining problem associated with silver nitrate administration. Povidone-iodine administration also does not appear to pose the risk of disturbance in acid-base balance and serum osmolality associated with mafenide, which is also frequently painful on application. The extensive use of povidone-iodine in burn therapy does pose the issue of iodine absorption. The literature suggests that this has received some attention. A study in dogs with granulating areas of 25% body surface, to which radioactive povidone-iodine solution was applied daily up to 36 days, failed to reveal any evidence of toxicity or foreign body reaction of the thyroid or of several other organs evaluated histologically and pathologically.6 In a clinical study of burn patients with more than 30% body surface denuded to granulation tissue, povidone-iodine solution applied as wet soak increased protein-bound iodine (PBI) levels by 20% (returning to normal in 4 to 6 wk),’ whereas in another study povidone-iodine spray applied to stasis ulcers reportedly resulted in no “appreciable” changes in PBI levels.* There is no mention in these two studies of other thyroid function tests or of any clinical signs of disturbed thyroid function. No abnormal rise in PBIs or T, or T4 levels were observed in ten patients following application of povidone-iodine ointment to the urethal meatus twice daily for many months .g In our own limited experience, we observed no clinical signs of disturbed thyroid function.

314

LINKER ET AL.

SUMMARY

AND

CONCLUSION

Control of microbial growth at burn sites by topical antiseptics can eliminate septicemia as th,e primary cause of death in burn patients. A retrospective examination of 10 yr of burn experience in two pediatric institutions, comparing results obtained with several topical antiseptics employed, suggests that Betadine Solution and Betadine Aerosol Spray are effective antimicrobial agents. They appear to be somewhat more effective than several agents studied and comparable in efficacy with silver nitrate, and do not appear to pose the hazard of electrolyte loss associated with silver nitrate administration. If further experience confirms our observations, the Betadine preparations will prove to be a welcome addition to agents used in burn therapy. REFERENCES 1. Ark, C. P., and Concrief, J. A.: The Treatment of Burns (ed. 2). Philadelphia, Saunders, 1969, p. 305. 2. Altmeier, W. A., and MacMillan, B. G.: Comparative studies of topical silver nitrate, sulfamylon and gentamicin. Ann. N.Y. Acad. Sci. 150:966, 1968. 3. Moncrief, J. A.: Topical therapy. Surg. Clin. N. Amer. 50:1301, 1970. 4. Ark, C. P., and Moncrief, J. A.: Topical therapy. Surg. Clin. N. Amer. 50:266, 1970. 5. Feller, I., and Crane, K. H.: National Burn Information Exchange. Surg Clin. of N. Amer. 50:1425,1970.

6. Georgiade, N. G., Matton, G. E., and vonKesse1, F.: Facial burns. Plast. Reconstr. Surg. 29~648, 1962. 7. Connell, J. R., Jr., and Rousselot, L. Povidone-iodine, extensive surgical M.: evaluation of a new antiseptic agent. Amer. J. Surg. 108:849, 1964. 8. Garnes, A. L., et al.: Clinical evaluaiton of providone-iodine aerosol spray in surgical practice. Amer. J. Surg. 97:49, 1959. 9. Landes, R. R., et al.: An aid in prevention of infections: topical application of an ointment to the urethral antibacterial meatus. Scientific exhibit, Southern Medical Association, Dallas, Tex., NOV. 16-19, 1970.