The effects of anesthesia and mode of delivery on the parameters of the renin-angiotensin system.

Paired maternal venous (MV) before (P1) and after (P2) general anesthesia, cord venous (CV) and cord arterial (CA) blood was taken from two groups of primagravid women, one delivered vaginally and the other by elective lower segment Caesarian section (ELSCS). ACTH, Cortisol (CoSol) Aldosterone (Aldo) Plasma Renin Activity (PRA) Plasma Renin Concentration (PRC) Angiotensin II (AII) Solium (N alpha) and Potassium [K]+ were measured in both study groups. Of the various hormones studied, all but cortisol were raised in the P2 sample with only ACTH and AII achieving significant increase. A number of significant positive correlations was found between P1 and P2 samples as well as between the hormones themselves. Four of the vaginally delivered group received epidural analgesia and demonstrated significantly higher levels of ACTH and CoSol in the CV sample. A comparison of the studied variables between the two groups showed a significant decrease in the ELSCS group of ACTH and CoSol in the MV sample, of ACTH, CoSol, PRC in the CV sample, and of CoSol in the CA sample. Of all the parameters, studied, only [K]+ together with Aldo was found to be elevated in the CV sample of the ELSCS group but only [K]+ achieved significant increase.