A prospective randomised controlled trial to investigate the effect of local anaesthetic in vivo on cell culture.

Cell culture is an important adjunct in the management of major burns in that it enables keratinocytes derived from the patient to be grown and used to attain cover when there is little autologous skin available. The purpose of this prospective randomised trial was to determine if the type of local anaesthetic used to harvest the skin biopsy in vivo affected the subsequent culture of keratinocytes. Lignocaine 1% was compared with a eutectic mixture of local anaesthetic (EMLA) and a control. The subjects recruited were patients undergoing abdominoplasty. Sixteen patients were recruited but two were excluded from final analysis due to infection of the culture medium in one and poor yield from biopsies in all groups in the other. The tissue to be removed from the abdomen was divided into three areas. EMLA was applied to a 5x5 cm randomised area 2 h prior to surgery. Lignocaine 1% was injected into a 5x5 cm randomised area of abdominal skin immediately after anaesthesia. The third 5x5 cm randomised area was used as a control. Three 4-mm punch biopsies were harvested from each site of local anaesthetic application as well as the control area. The Rheinwald & Green method was used to culture these cells [Rheinwald JG, Green H. Serial cultivation of strains of human epidermal keratinocytes: the formation of keratinizing colonies from single cells. Cell 1975;6:331-5.] Cell counts were performed after harvesting keratinocytes from the biopsy and after 10 days of culture. Statistical analysis was undertaken. In conclusion, in contrast to in vitro studies when lignocaine 1% or EMLA is applied in vivo, there is no inhibition of cell culture. In vivo EMLA was also found to significantly increase cell multiplication.