Microsoft Word - NEF308BF

M.E. De Broe, MD, PhD, Department of Nephrology-Hypertension, University Hospital Antwerp, Wilrijkstr. 10, B-2520 Edegem (Belgium) Dear Sir, Methods In a recent article in this journal [1], Faro et al. studied the influence of C02 changes, due to Co2 extraction during acetate dialysis, on the central venous blood composition and their effect on the pulmonary ventilation. They postulated that the decrease in C02 in the venous line blood has influence on the central venous blood composition, and that this plays a role in the control of the pulmonary ventilation in these patients. In this communication we present our results on the influence of C02 loss through the dialyzer on the carbon dioxide tension measured in the pulmonary artery (mixed venous blood). Ten patients, mean age 54,7 years (24–72 years), 6 male and 4 female, undergoing 4-hour maintenance hemodialysis sessions three times weekly, were studied. Nine patients were studied during hemodynamic monitoring for evaluation of different cardiac problems. They were all critically ill at the time of the study and treated with oxygen through a nasal cannula. One male patient volunteered to participate in the study. All patients gave informed consent. The patients were dialyzed with acetate-containing dialysate and a single-needle, double-headed pump system. A Swan-Ganz thermodilution catheter (93A-131H-7F; Edwards Laboratory, Santa Anna, Calif., USA) was introduced percutane-ously through the internal jugular vein into the pulmonary artery, at least 15 min before the start of the first measurement. Blood samples were drawn from the pulmonary artery and from the arterial side of