Central blood pooling as an explanation for lowered FRC during anaesthesia? Thigh volume measurements by plethysmography.
Segmental volumes of the thigh and the upper arm were measured by means of an air-filled plethysmograph before and during various anaesthesias. A small but significant fall in segmental volume was seen with the induction of anaesthesia with thiopentone. A further fall was observed during neurolept anaesthesia but not with halothane. Epidural and spinal anaesthesias caused no change in segmental thigh volume. The results suggest a redistribution of 50-150 ml blood from the extremities to the trunk during general anaesthesia. This redistribution may contribute to the well-known fall in FRC with general anaesthesia.
D000005:Abdomen / Q000098:blood supply; D000293:Adolescent; D000328:Adult; D000368:Aged; D000758:Anesthesia; D000765:Anesthesia, Conduction; D000769:Anesthesia, Inhalation; D000771:Anesthesia, Intravenous; D001132:Arm / Q000098:blood supply; D005260:Female; D005652:Functional Residual Capacity; D006801:Humans; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D010991:Plethysmography; D012039:Regional Blood Flow; D013848:Thigh / Q000098:blood supply*; D013909:Thorax / Q000098:blood supply