Burns (1989) 15, (S), 343-345 Rinted in Grent Britain 343

Abstracts

CLINICAL STUDIES

Early excision and serum endotoxin levels Sera from 19 patients with a wide range of burn injuries were analysed for endotoxin levels to determine whether early excision and grafting of the wound altered the endotoxin levels. An early endotoxaemia was found between 7 and 12 h and at 4 days postburn. The level of circulating endotoxin was reduced by early wound excision. Late wound excision was associated with a transient rise of endotoxin levels.

Dobke M. K., Simoni J., Ninnemann J. L. et al. (1989) Endotoxemia after burn injury: effect of early excision on circulating endotoxin levels. 1. Bum Cure R&bi~. 10, (2). 107-111.

Lymphocyte blastogenesis and interleukin-2 Samples of diluted serum taken from nine patients with burns, three of whom had injuries covering more than 60 per cent of the body surface area, were analysed for their ability to suppress mitogen-induced lymphocyte blastogensis - a process which is partially mediated by interleukin-2. A separated aliquot of stimulated cultured lymphocytes was tagged with a monoclonal antibody to interleukin-2 receptors. The sera from the three patients with large burns was significantly more suppressive than that taken from patients with smaller burns. The sera from the patients with large burns also caused a marked reduction in the interleukin-2 receptor labelling index, suggesting that it possesses factor(s) that directly or indirectly block T-lymphocyte interleukin-2 receptor expression.

Ferrara J. J., Peterson R. D, Hester R. et al. (1989) Inhibition of lymphocyte blastogenesis caused by suppression of interleukin-2 receptor sites after thermal injury. J. Bum Care R&&l. 10, (2) 119-124.

Atracurium kinetics and dynamics The pharrnacokinetics and phannacodynamics of atracurium (0.5 mg/kg, given i.v.) was measured in five burned patients and four non-burned controls. The decline of plasma atracurium concentration with tie was biexponential in both groups of patients. There were no significant differences in the value of any pharmacokinetic parameter. The time-course of effect was also similar although the maximal twitch depression was significantly smaller and the time to recover to 50 per cent of maximal twitch depression was significantly shorter in the burned patients. Burned patients had an EC,, that 3.4 times that was found in control patients. The plasma-free fraction of atracurium in the burned patients was 75 per cent of that found in the controls and the free EC,, of the burned group was 2.7 times that of controls.

Marathe P. H, Dwersteg J. F., Pavlin E. G. et al. (1989) Effect of thermal injury on the phannacokinetics and pharmacodynamics of atracurium in humans. Anesfhesiokgy 70, (5), 752-755.

Tracheostomies in burned patients The effects of 99 tracheostomies performed in 3246 bumed patients who had indications of prolonged respiratory failure or

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acute loss of airway were reviewed. Although colonization of the sputum was universal, neither rates of pulmonary sepsis nor mortality were significantly increased in the tracheostomy patients. Late upper airway sequelae were found in 28 patients including tracheal stenosis, tracheoesophageal fistula and tra- cheoarterial fistula. The duration of intubation correlated only with the development of tracheoarterial fistula. The patients with this complication were significantly older and were more likely to have evidence of tracheal necrosis at the time of the tracheostomy.

Jones W. G., Madden M., Finkelstein J. et al. (1989) Tracheosto- rnies in burn patients. Ann. Surg. 209, (4, 471-474.

Early versus late excision and grafting A randomized study of early excision and grafting versus late skin grafting after spontaneous eschar separation was carried out in 85 patients with ages between 17 and 55 years and with burns covering more than 30 per cent of the body surface area. Mortality from burns without inhalation injury was significantly reduced by early excision and grafting from 45 per cent to 9 per cent in patients with ages between 17 and 30 years. No differences in mortality were found between the therapies in patients over 30 years or with a concomitant inhalation injury. Children (n = 259) with similar large burns treated by early excision showed an increasing mortality rate with increasing burn size and with concomitant inhalation injury.

In both children and adults the mean length of hospital stay for survivors was less than I day per per cent of total body surface area bum.

Hemdon D. N., Barrow R. E., Rutan R. L. et al. (1989) A comparison of conservative versus early excision therapies in severely burned patients. Ann. Swg. 209, (5). 547-553.

Lymphocyte content of leucocyte isolates Measurements were made to determine why Ficoll-Hypaque purified leucocyte preparations from burned patients showed an increased spontaneous blastogenic transformation (SBT) when mitogen-stimulated blastogenesis was impaired. Neither selective lymphocyte subpopulations nor macrophage depletion returned the increased SBT to normal. Apparently leucocyte preparations from burned patients contain fewer lymphocytes than controls.

Studies of the relative contributions of T cells and non-T cells to the increased SBT showed that while both groups of cells were activated, the non-T cells were primarily responsible for the increased SBT. It is concluded that peripheral blood from burned patients contains a large fraction of metabolically active non- mononuclear cells that co-sediment with mature lymphocytes.

Deitch E. A., Xu D. H., Sittig K. et al. (1989) Ficoll-Hypaque leukocyte preparations from burned patients contain activated non-lymphoid cell populations that take up thyrnidine. J. Trauma 29, (3), 277-283.

High-frequency ventilation for inhalation injury As high-frequency percussive ventilation, but not normal ven- tilation, had been found to produce normocapnia and an arterial