Peripheral blood T and B lymphocytes in patients with burns. I. Test parameters and clinical evaluation of the rosette assays

Rosetting techniques identifying receptors for sheep red blood cells, for Fc in antigen-antibody complexes (EA) and C₃ in antigen-antibody-complement complexes (EAC) were employed in the sequential evaluation of 10 normal individuals over an 8-week period and in the testing of burn patients' blood samples. Mean values with standard deviations were 59 ± 7 per cent or 959 ± 260 E rosettes, 34 ± 6 per cent or 500 ± 186 EA rosettes and 41 ± 7 or 657 ± 214 EAC rosettes. Variations in percentage results were attributed to the handling of rosetted cells for counting. Variations between samples from the same individual were similar to variations between samples from different individuals. Lymphocyte preparation of peripheral blood samples from burn patients resulted in red cell contamination of the separated lymphocytes. Ox red cell rosette assay and E and EAC percentages were used to evaluate samples from burn patients for non-rosetting cells or possible multiple reactive cells to explain diverse results obtained from these samples relative to normal control samples.     

Peripheral blood T and B lymphocytes in patients with burns. II. Sequential rosette analyses considering burn severity and pseudomonas sepsis

Lymphocytes have been enumerated by E rosette assay for T lymphocytes and by EA and EAC rosette assay for B lymphocytes in 49 burn patients sequentially for 30 days following thermal injury. Severity of burn was used as a classification in a separate analysis of patients. Significant depressions in T lymphocyte percentages and counts per mm³ were seen in the early post-burn period, the magnitude of which increased with increasing severity of burn. There was a trend towards elevated levels of EAC rosetting cells in mild to moderate injury but there was an absolute depression in severe injury.Extreme depressions of T lymphocytes have been consistently seen in patients who coincidentally developed clinically evident pseudomonas sepsis.     

Assessment of burn wound sepsis by swab, full thickness biopsy culture and blood culture--a comparative study

Fifty patients with burns ranging from 30 to 50 per cent of their body surface area were monitored for sepsis throughout their hospital stay using swab, blood and full thickness biopsy culture techniques. The relative merits of these techniques in the diagnosis of burn wound sepsis were evaluated. Only 62.5 per cent of the patients with a positive surface culture showed signs of clinical sepsis, while 87.5 per cent of the patients with significant bacterial count on biopsy culture showed signs of clinical sepsis. A decrease in bacterial count on follow up correlated with clinical improvement while a count of 10(8) orgs/gm indicated a bad prognosis. Wound surface cultures, though the simplest method gave poor indication of the organisms invading into the burn wound. Blood cultures were of only prognostic value. Full thickness biopsy culture and quantification of the number of bacteria in the burn wound was felt to be the best method for rapid diagnosis and for assessing the progress of burn wound infection.     

Rapid quantification of bacterial and fungal growth in burn wounds: biopsy homogenate Gram stain versus microbial culture results

A prospective analysis of 370 burn wound biopsies was done to correlate Gram-stain results from biopsy homogenates with quantitative culture results. The number of bacteria seen in a total of 10 oil immersion microscope fields of Gram-stained homogenates was correlated with significant microbial growth (1 x 10(5) organisms/gram of tissue) of the same biopsy homogenate plated on trypticase soy agar. Of the biopsies examined, Gram-negative rods were present in 36.8 per cent, Gram-positive cocci in 49.7 per cent and yeast in 15.9 per cent. Mixtures of organisms were present in 24.3 per cent. When Gram stains showed one or more organisms per oil immersion microscope field, the correlation with significant microbial growth was 94.5 per cent or more. When five or more organisms were seen per field, the correlation with significant growth became 97 per cent or greater. When no organism was seen on Gram stain, the cultures grew significant numbers of organisms 19.1 per cent of the time or less. This false-negative rate was considered to be high. It is believed, however, that this method of early detection of significant burn wound microbial growth may prove to be valuable in the management of severely burned patients.     

The quantitative swab culture and smear: A quick, simple method for determining the number of viable aerobic bacteria on open wounds.

The quantitative swab culture is a reliable method for quantifying the number of viable bacteria colonizing open wounds. For open wounds in burn patients, the swab bacterial count is linearly related to biopsy quantification of viable bacteria in the underlying tissue. This technique is simple and requires no surgical manipulation of the wound. For a wound of uniform appearance, the standard deviation of a single swab culture from the mean log bacterial count for a series of cultures from widely spaced areas on the wound is +/- 0.85 logs; 95% confidence limits are +/- 1.7 logs from the mean. A Gram-stained smear from a wound swab requires less than 10 minutes to prepare. Visualization of bacteria on the smear indicates that 106 or more bacteria per swab are present. The value of the smear and swab techniques for predicting safe wound closure may be inferred from the published reports of others and the direct relationship between the swab and biopsy counts of viable bacteria for open wounds.     

The staging of Hodgkin''s disease: Preoperative clinical assessment versus operative evaluation

Fifty consecutive patients with the diagnosis of Hodgkin's disease, confirmed by lymph node biopsy, underwent preoperative clinical assessment and staging laparotomy between 1969 and 1974. Preoperative evaluation consisted of bone marrow examination, liver and spleen scans, intravenous pyelograms, lymphangiograms, and standard chemical laboratory tests. Operative evaluation consisted of splenectomy, liver biopsy, periaortic, mesenteric, and celiac lymph node biopsy, appendectomy, and iliac crest bone biopsy. Twenty-three patients (46 per cent) were improperly staged by preoperative clinical assessment, with twelve patients being overstaged and eleven patients being understaged. Liver and spleen scans, and intravenous pyelograms were of little value in assessing organ involvement with Hodgkin's disease. Lymphangiograms similarly were of questionable value, being interpreted as positive in twenty-one patients but histologically involved in only seven patients (overread, 67 per cent. Fourteen patients had negative lymphangiograms, with five being histologically involved (underread, 36 per cent). There was a 22 per cent incidence of pulmonary complication (atelectasis, pneumonitis) but no deaths or life-threatening complications.     

Correlation of quantitative burn wound biopsy culture and surface swab culture to burn wound sepsis

The present study includes seventeen patients with second and third degree fresh burns involving 15–50 per cent total body surface area (TBSA). Surface swabs and quantitative burn wound biopsy cultures were obtained during postburn weeks 1,2 and 3 and correlation was studied. To obtain bacterial counts the technique described by Loebel et al. (1974) was used. The patients were divided in two groups depending upon burn body surface area involved. The first group includes five patients with burns between 15–29 per cent body surface area and the second group includes the rest of the twelve patients with burns between 30–50 per cent body surface area. No patient from group I showed any sign or symptom of sepsis whereas seven patients from group II developed sepsis and three died. These three patients showed positive blood culture at the time of death. Of the 48 cultures obtained in all the patients over 3 weeks, 7 cultures showed differences between swab and biopsy cultures. Genticyn was the most effective drug against Gram-negative organisms.     

An epidemiological profile and trend analysis of wound flora in burned children: 7 years' experience

A retrospective chart review was conducted of 5418 culture and sensitivity reports from 93 paediatric burn patients to determine profiles of wound flora and invasive organisms, trend analysis and patterns of antibiotic resistance. Coagulase-positive Staphylococcus was the predominant burn wound pathogenic isolate and the predominant invasive organism for burns less than 60 per cent BSA. Pseudomonads were the predominant invasive organism for burn wounds greater than or equal to 60 per cent BSA. Only 7 per cent of all pathogenic isolates were fungi. A significant association was demonstrated between increasing burn size and an increasing incidence of Gram-negative and invasive organisms. Silver sulphadiazine remains a very effective topical agent for the control of bacterial and fungal growth in burn wounds after 10 years of intensive use in this burn unit. Pseudomonad isolates were routinely multi-drug resistant. Pseudomonad isolates from wounds treated topically with a silver sulphadiazine-cerium nitrate mixture were frequently resistant to aminoglycosides, colistin and carbenicillin. It is concluded from this review that severe restrictions on antibiotic usage within burn units, and strict internal environmental control within burn units may help to decrease the incidence of nosocomial resistant strains and cross infection. Regular monitoring of burn wound flora, and the protocol for wound care used in treating these patients have been effective in preventing septic episodes and death due to sepsis.     

Anaerobic infections of burns

From August 1980 to June 1982, 102 burn wound specimens taken from 34 patients were studied for anaerobic cultures. Fifteen instances (14.7 per cent) from 8 patients were positive and altogether 12 species were found. The predominant anaerobes were Bacteroides melaninogenicus, Peptococcus, Bacteroides fragilis, and other strains of Bacteroides and Peptostreptococcus. They were mostly discovered in electric burn wounds and burn wounds affecting the perianal and oral areas. Wounds with anaerobic infection usually appeared gaseous, necrotic and ischaemic with foul odour. Nineteen blood samples from 10 burn patients were also studied for anaerobic cultures, and two were positive, one caused by Bacteroides and the other by mixed infection of Peptococcus and Serratia, indicating that the anaerobes played an important role in burn infections. It seems necessary to perform anaerobic culture studies in burn patients as a routine. A comparative study between anaerobic culture and indirect immuno-fluorescence method was undertaken for Bact. fragilis and Bact. melaninogenicus in 47 burn wounds. It showed that the immunofluorescence method was a more rapid, simple, sensitive and specific diagnostic method.     

A policy of early excision and grafting in elderly burn patients shortens the hospital stay and improves survival

Early excision and grafting of the burn wound appears to shorten the hospital stay and decrease mortality in children and adults. However, whether an early surgical approach is safe in elderly burn patients has not been resolved. To answer this question we carried out a prospective study of early surgery in 114 consecutive patients over the age of 50 years. Patients were generally operated on between post-burn days 2 and 5. The mean age of the patients was 68 years, with a burn size of 22 per cent, of which 13 per cent was full thickness skin loss. The mean hospital stay of the surviving patients was reduced by 40 per cent compared to national averages (P less than 0.001). The mortality rate for the entire group of patients was 17 per cent, with 2 deaths in the 65 patients with burns less than 20 per cent total body surface area (TBSA). Although the mortality rate for patients with burns greater than 20 per cent TBSA was 35 per cent, this was less than predicted (P less than 0.05). The improvement in survival appeared to be due to a decrease in the incidence of lethal burn wound infections.     

Comparison of the postburn hyperdynamic state and changes in lung function (effect of wound bacterial content)

The pulmonary and systemic response to a full-thickness burn (15% of total body surface area) was determined in 15 adult sheep. Also compared was the effect of wound bacterial content and prostanoid release on this response. Burn wound thromboxane A2, measured as TxB2, and prostacyclin, measured as 6-keto-PGF1 alpha, were measured in burn wound lymph. Animals were monitored for 7 days. On the final day, a full-thickness biopsy specimen of burn tissue was obtained for quantitative bacteriology. Wounds with 10(4) or less organisms per gram of burn tissue were considered colonized, whereas those with 10(5) or more organisms per gram of burn tissue indicated wound infection. Seven sheep had 10(4) or less bacteria and the remaining eight sheep had 10(6) or greater bacteria. We noted a significant mean increase in cardiac index from a baseline of 5 to 6.2 L/min/m2, a decrease in systemic vascular resistance from 16 to 12 mm Hg/L/min, and a mean increase in oxygen consumption from a baseline of 135 to 165 ml/min/m2 during the 7-day study period. There were no differences in these responses between the colonized and the infected wounds. Pulmonary artery pressure increased from a mean baseline of 19 to 24 mm Hg and arterial oxygen tension (PaO2) decreased from a baseline of 90 to 80 mm Hg in the infected wound group, with values remaining at baseline in the colonized wound group. These changes corresponded with an increase in lymph and plasma TxB2 from a baseline of 200 to 210 pg/ml to 1000 +/- 250 and 600 +/- 190 pg/ml, respectively. Values in the animals with colonized wounds were not significantly increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

烧伤创面脓毒症诊断的细菌学意义及临床分期

目的　探讨并重新评价烧伤创面脓毒症与组织细菌定量的关系 ,将其进行临床分期。　方法　对近 5年符合条件的 32例烧伤患者进行组织细菌检查和定量分析 ,结合临床表现对创面脓毒症进行分期。　结果　 (1) 32例患者的 12 3个组织标本中 ,均可见到细菌侵入 ,有 82个标本的每克痂下组织菌量≥ 1× 10 5,4 1个标本的每克痂下组织菌量 <1× 10 5。其中 18例患者 6 8个标本 ,每克痂下组织菌量全部≥ 1× 10 5;5例患者 2 0个标本 ,每克痂下组织菌量全部 <1× 10 5;其余 9例患者的标本中仅部分每克痂下组织菌量≥ 1× 10 5。 (2 )根据细菌学结果并结合临床表现 ,可将创面脓毒症分为Ⅰ～Ⅳ期。　结论　 (1)临床有中毒表现并获得细菌侵入活组织的证据时 ,创面脓毒症的诊断即可成立。 (2 )将创面脓毒症分为IV期 ,有助于规范临床诊断、指导临床治疗     

Are burn wound biopsies obsolete? A comparative study of bacterial quantitation in burn patients using the absorbent disc and biopsy techniques

A study of bacterial quantitation in burn wounds was undertaken to compare a new absorbent paper disc technique with the standard burn wound biopsy technique. In the first part of the study 228 paired samples were used to compare the two methods; a high correlation coefficient was found with the four most commonly encountered bacteria, and both methods showed a high specificity and sensitivity for each of the organisms. In the second portion of the study, the discs were compared with burn wound biopsies that had been divided into their superficial and deep segments. Thirty paired samples were studied and again the correlation was high, indicating that the disc technique also measured the organisms found in the deeper tissue levels. The absorbent disc technique is simple, convenient, noninvasive, inexpensive, and yields reproducible results. These findings indicate that burn wound biopsies may no longer be required for infection monitoring in the burn patient.     

Permeability of thermally damaged skin V: Permeability over the course of maturation of a deep partial-thickness wound

The permeability of eschar is an important factor governing rational approaches to topical control of burn wound sepsis. Previous work has shown the burn wound to have a highly variable permeability immediately after burning depending on the manner of burning. But the burn is also a dynamic wound and its physical state changes during the process of maturation. The present studies are an early attempt to characterize wound permeability as a function of maturation. Hairless mice were burned dorsally for 15 seconds on a metal surface maintained at 80°C. The time and temperature conditions were chosen to effect a deep partial-thickness to full-thickness injury on the animal. Mice were sacrificed daily post burn over a 2-week period and the permeabilities of ³H-methanol and ¹⁴C-butanol through the excised eschar were measured. The eschar permeability coefficients were directly compared to permeability coefficients for the same compounds found with abdominal skin sections taken concurrently from each animal. It was observed that the branding initially caused a 50 per cent increase in the permeability of methanol and a 300–400 per cent increase in the permeability of butanol. These factors held over the first 4 to 5 days of maturation. Thereafter permeabilities tended to increase, gradually at first, but accelerating to a maximum which was observed at approximately 10 days. At the maximum, methanol's permeability was 20 times and butanol's 12 times their normal values. For both compounds permeability of eschar decreased past the maximum until termination of the studies at 14 days.     

Selective intestinal decontamination for prevention of wound colonization in severely burned patients: a retrospective analysis.

In this study the effect of selective intestinal decontamination of the digestive tract (SDD) on wound colonization was investigated. Ninety-one patients with at least 25 per cent total burned surface area (TBSA) were included in this study. All patients received oral polymyxin. In 63 patients oral co-trimoxazole and amphotericin B were added to the regimen. The addition of co-trimoxazole decreased the incidence of Enterobacteriaceae wound colonization from 71 per cent to 11 per cent (P less than 0.005). Colonization with Proteus was eliminated in patients treated with co-trimoxazole, compared with an incidence of 36 per cent in the group treated with polymyxin alone (P less than 0.001). The addition of amphotericin B decreased yeast colonization of the burn wound from 39 per cent to 10 per cent (P less than 0.005). A close relation was observed between burn wound colonization and colonization of the gastrointestinal tract. No resistant bacterial strains emerged during the period of study. These results suggest that SDD is an effective method for prevention of wound colonization. Further controlled studies are needed to establish the role of SDD in preventing burn wound colonization and wound sepsis.     

The role of sampling in the detection of microbial contamination on cadaveric allograft skin used as a biological wound dressing

The availability of cryopreservation and low temperature storage techniques for cadaveric allograft skin allows it to be preserved while microbial assessments are made before its use as a temporary biological dressing on burn wounds. In a 300-donor, 5-year prospective study, we tested ten skin samples from defined areas on each donor for microbiological contamination. Although the skin from 52.3 per cent of the donors possessed some detectable residual microbial contamination after surgical body preparation and skin removal, such contamination was limited to an average of 1.4 areas per body, leaving 86 per cent of all skin obtained free from detectable contamination and suitable for use as biological wound dressings. The number of skin samples tested per donor body determined the accuracy of detection of the presence of contamination. Testing one skin sample per donor body yielded a correct skin assessment 92 per cent of the time, while testing five skin samples increased the accuracy to 96 per cent, and testing ten skin samples yielded a 99.9 per cent accuracy in detection of skin contamination. Thus, it is within the ability of a skin bank to set the limits of microbiological risk to patients receiving processed cadaveric allograft skin.     

Bactericidal efficacy of 5 per cent povidone iodine cream in Pseudomonas aeruginosa burn wound infection

A new topical antiseptic agent, 5 per cent polyvinylpyrrolidone-iodine (PVP-I) cream, with altered physicochemical properties, incorporated in a different carrier base has proved in vivo to be more effective in controlling burn wound infections than 10 per cent PVP-I ointment. Important biodynamic properties of the new formulation have not, however, been elucidated in vivo. Hence the need for a controlled study to evaluate the bioavailability of the active component after penetration through burn eschar; the bactericidal efficacy of the cream and determination of the bactericidal time of the cream in comparison with 10 per cent PVP-I ointment. A modified Walker burn wound model was used to define the rate of trans-eschar penetration, biodynamic availability and bactericidal efficacy of 5 per cent povidone iodine cream in established Pseudomonas aeruginosa burn wound infection. In vitro penetration confirmed the effective diffusion of PVP-I cream through 1.5 mm eschar within 6 h. A single topical application of PVP-I cream resulted in a 98.8 per cent (6.088 x 10(9) c.f.u./g of tissue to 7.367 x 10(7) c.f.u./g of tissue) reduction in intra-eschar viable organisms within 18 h after application. A second topical application of PVP-I cream at 18 h resulted in a total reduction of 99.8 per cent in viable organisms (2.90 x 10(9) c.f.u./g of tissue to 7.009 x 10(6) c.f.u./g of tissue) within 48 h. Comparing the in vitro bactericidal time of povidone iodine ointment with cream against Pseudomonas aeruginosa, Staphylococcus aureus and a Klebsiella pneumoniae revealed that the PVP-I cream killed organisms ten-fold more quickly than the ointment.(ABSTRACT TRUNCATED AT 250 WORDS)     

Clinical experience with biobrane® biosynthetic dressing in the treatment of partial thickness burns

Biobrane®, a synthetic, bicomposite wound dressing, has been used to treat 17 patients with partial thickness burn wounds covering 0·5–12·5 per cent of the total body surface area (mean 4·4 per cent). In 16 patients we found complete healing of the wound after removal of the dressing, 6–15 days after the injury. In one patient, the wounds were determined on the third day post-injury to be deeper than initially suspected, and she was taken to the operating room for surgical debridement and grafting. Biobrane is an effective wound covering for clean, superficial partial thickness burns of limited extent; the simultaneous use of topical antimicrobial agents for such wounds is not necessary.     

The clinical use of a tubular compression bandage, Tubigrip, for burn-scar therapy: a critical analysis

Control of burn-scar hypertrophy remains a priority in the care of the burn patient. However, because of the problems associated with traditional compression therapy methods a study of the clinical utility of a tubular compressive bandage (TCB) was initiated. The clinical effectiveness of TCB was determined by studying 210 separate anatomic burn sites in 88 burn patients with a mean age of 25 years and a mean burn size of 21 per cent of the total body surface area (TBSA). To facilitate analysis of the results the patients were divided into two groups, the first group consisted of 71 patients who received prophylactic pressure therapy and a second group of 17 patients who received therapeutic pressure therapy after the establishment of hypertrophic scars. Mean follow-up of the entire group of patients was 11 months. The anatomic area involved by the burn was the most important factor in determining the effectiveness of TCB in this study. Failures primarily occurred at sites of mobility where pressure could not be consistently delivered or maintained, including the digits of the hand, axilla, groin and the head/neck regions. Overall, 85 per cent of the anatomic sites treated had good or satisfactory results. Based on the results of this study, we use TCB on all burn patients, who are at risk of developing burn-scar hypertrophy, immediately after the burn wound has healed or been surgically closed.     

An evaluation of the role of systemic antibiotic prophylaxis in the control of burn wound infection at the Lagos University Teaching Hospital

A prospective study was carried out on 61 patients to evaluate the role of systemic antibiotic prophylaxis in the control of burn wound infection. The patients were randomised into three groups: group 1 (n=21) received ampicillin and cloxacillin; group 2 (n=20) received erythromycin and genticin and a control group (n=20) received no systemic chemo prophylaxis. The burn wounds were similarly managed. Wound colonisation was determined from surface wound swab cultures and wound infection was determined from wound biopsy cultures and histopathology. The colonisation time (days) for the groups was 2.90+/-0.92, 3.15+/-0.77 and 3.05+/-0.83 for groups 1 and 2 and the control, respectively. The commonest organism isolated from contaminated wounds was Staphylococcus aureus. Wound infection was established in 5.70+/-1.70, 5.75+/-1.62 and 5.6+/-1.90 days for group 1, group 2 and the control group, respectively. There was no significant difference between wound infection time of control and group 1 nor was there such difference between the control and group 2 (P>0.05). The commonest organism infecting burn wounds in all the groups was Pseudomonas aeruginosa followed by S. aureus. There was however a significant difference between the treatment groups and the control (P<0.05) with regard to the percentage of infected wounds that grew P. aeruginosa, compared to those that grew S. aureus. It was concluded that systemic antibiotic prophylaxis is of no value in controlling burn wound sepsis, and might even favour the growth of P. aeruginosa in the burn wounds.