536 LETTRES A LA REDACTION

R6ponse

L'influence respective du d6bit de prdl6vement et de la longueur du tube d'6chantillonnage a 6t6 rdcemment 6tudide sur le ddlai de rOponse et le temps de r6ponse [1]. L'augmentation du d6bit de pr616vement rdduit ces deux paramOtres temporels, alors que l'augmentation de la longueur du tube de prdlOvement augmente le temps de transit sans affecter le temps d'ascension. En pratique, ces auteurs proposent l'6valuation du temps de rdponse total (somme des deux temps d6crits prOcd- demment), qui doit ~tre toujours infdrieur ~ la durde d'un cycle respiratoire.

En 0tat stable, la ventilation en pression positive ?~ basse frdquence (9 c • min 1) permet une r6duction significative du gradient Paco2-Petco2 par diminution

relative de l 'effet espace mort [2]. Une hyperinsufflatlon pulmonaire unique peut 6ventuellement permettre une meilleure distribution de la ventilation, mais sa r6elle efficacit6 clinique quant ~ la r6duction du gradient a-etPco2 mdriterait d'6tre d6montrde et comparde ~ la variabilit6 indwiduelle et temporelle de ce gradient.

N6anmoins, bien que la P~tco2 ne refl~te pas exactement la Paco2, la capnographie reprdsente un outil prdcieux de monitorage respiratoire en anesth6sie.

[1] FLETCHER R., JONSON B. Br. J. Anaes th , 56 : 106, 1984 - - [2] SCHENA J e t al. Crtt. Care Med . , 12 : 672, 1984.

J.L. BOURGAIN

Ddpartement d 'Anesthdsie-Rdammation CHU de Blc6tre 94275 Le Kremhn-Blc6tre Cddex

Transplantation hepatique- projet de cr6ation d'un Groupe europeen

Liver transplantation ~s employed increasingly in the management of end-stage and otherwise incurable liver disease. The principal activity is based on Sir Roy Calne's unit in Cambridge, but there are now many other European centres. Previous meenngs held in Cambridge, as well as those in Pittsburgh, have demonstrated a wide interest in the problems generated by l~.ver transplantation among anaesthetists, physicians, biochemists, haematologists, immunologists and nurses, as well as surgeons. There would seem to be a need for a regular forum where people can meet and discuss their problems.

Accordingly it is planned to set up such a group. The first meeting will be held in the School of Clinical

Medicine, University of Cambridge, Addenbrooke's Hospital, on March 25th and 26th, 1988. It will consist in part of clinical presentations of various aspects of the care of patients undergoing liver transplantation, of workshop and poster sessions, and of a business meeting to decide on the constitution of the group. Anyone interested in attending or presenting their results is invited to write to me by 31st January, 1988.

J V FARMAN

Intensxve Care Unit Addenbrooke 's Hospital Cambridge CB2 2QQ U.K.