Hemodialysis associated hypoxia extends into the post-dialysis period.

To investigate whether hypoxia extends into the post-hemodialysis period, nine clinically stable-end stage renal disease patients were dialyzed against bicarbonate and one against an acetate batch, all with bioincompatible dialyzers. None had clinical evidence of cardiopulmonary overload on the day of the study. Using an oximeter with internal memory, oxygen saturation was monitored continuously at the beginning, during, and for four hours after hemodialysis. Hypoxia was defined as oxygen saturation less than 85%. Three patients had no hypoxia during or after dialysis. Hypoxia occurred in five patients both during and after dialysis, and in two patients only in the post-dialysis period. Episodes of hypoxia were of longer duration and severity in post-dialysis period. We conclude that significant hypoxia can occur in the post-hemodialysis period.