A MAXIMAL CENTRAL VENOUS OXYGEN-SATURATION (SVO(2)MAX) FOR THE SURGICAL PATIENT

Before induction of anaesthesia, 23 patients scheduled for major abdominal surgery bad blood samples drawn from a central venous catheter for oxygen saturation (SvO(2)) after graded infusion of isotonic saline. The infusion of saline was continued until further administration resulted in a stable SvO(2) (SvO(2)max). The SvO(2) increased from 69 (53-83) to 72 (66-83) % (median and range; P < 0.0001), when the patients received 10 (0-26) mL . kg(-1), average 500 mL, of saline. At the same time central venous haematocrit decreased from 38 (32-47) to 36 (23-47) % which suggests that the intravascular volume was expanded by 420 (180-3070) mL or by 72 (18-174) % of the administered volume. The results demonstrate that volume expansion by saline can establish a maximal venous oxygen saturation in the surgical patient.