Cardiovascular Function and Alveolar Gas Exchange during Isovolemic Hemodialysis with Acetate in Healthy Man

Abstract

In order to elucidate the hemodynamic responses and alveolar gas exchange during isovolemic hemodialysis (IHD), without the influence of the uremic state and its complications, 7 healthy men underwent IHD. The dialysate contained acetate (40 mmol/l) and the sodium concentration was adjusted to the individual’s predetermined plasma sodium concentration. By invasive techniques cardiac index (thermodilution), stroke index, heart rate, brachial and pulmonary arterial blood pressures, systemic vascular resistance index, central blood temperature, P_aO₂ and P_aCO₂ were measured. Calf vascular resistance was assessed by venous occlusion plethysmography. Plasma acetate was determined. A recirculation period of 30 min was followed by 120 min of IHD. During IHD plasma acetate increased to 2.51 ± 0.30 mmol/l. Acetate provoked vascular dilatation, which was compensated for by a heart rate-dependent increace in cardiac index. Brachial arterial blood pressure and stroke index remained unchanged. P_aCO₂ and plasma bicarbonate decreased significantly, P_aO₂ tended to decrease and blood pH were unchanged. Thus, IHD with acetate in healthy man is mainly characterized by vasodilatation, but no cardiodepressive effects or marked hypoxemia. The adaptation to IHD is similar to that observed during treatment of uremic patients without complications.

Cardiovascular Function and Arterial Blood Gases during Sham Dialysis in Healthy Man

“…We have previously studied the hemody namic effects of isovolemic acetate hemodi alysis [21] and isolated ultrafiltration [22] in healthy volunteers, and found the hemody namic effects of these procedures to be qual itatively similar to those observed in pa tients with uremia. However, it could not be ruled out that the blood-membrane contact per se might have modified the cardiovascu lar response to these procedures to some extent, considering that pulmonary hyper tension has been reported after the injection of cuprophane-incubated plasma in sheep [11] and during cuprophane SHD in patients with chronic uremia [14].…”

Cardiovascular Function and Arterial Blood Gases during Isolated Ultrafiltration in Healthy Man

“…In the present study in healthy subjects, oxy gen tension was not changed after overhy dration or during ultrafiltration. In previous studies of isovolemic acetate dialysis [28] and sham dialysis [29] in healthy subjects, the changes in oxygen tension were small and insignificant.…”

“…In a previous paper we reported the he modynamic responses to isovolemic hemo dialysis in healthy subjects with acetate as the buffer source [28]. Acetate caused a pe ripheral vasodilatation, which was compen sated for by a heart rate-dependent increase in cardiac output with a maintained blood pressure.…”