Studies on Autonomic Blockade. Ii. Observations on the Nature of Blood Pressure Fall With High Selective Spinal Anesthesia in Pregnant Women 1

The Effect of High Spinal Anesthesia on the Renal Hemodynamics and the Excretion of Electrolytes During Osmotic Diuresis in the Hydropenic Normal Pregnant Woman 1

“…The response of the blood pressure and pulse rate to the spinal blockade followed the same pattern described in other papers (1,2). It will be seen that the blood pressure dropped markedly during the first few periods following spinal anesthesia and began to return to control levels at the onset of the last period.…”

“…The pulse rate showed similar variation. The side effects of the procedure were the same as listed in other papers (1,2) Figure 1 it will be seen that these cases fit well on the flow-load curve as described previously (3) Renal plasma flow (RPF) . 5 The effect of spinal blockade on renal plasma flow is consistent for all five subjects.…”

“…(Submitted for publication May 21, 1951; accepted June 18, 1951) In previous papers (1,2) it was demonstrated that the normal pregnant woman subjected to autonomic blockade with high spinal anesthesia develops a marked fall in blood pressure leading to a shock-like state.…”

Effects of Autonomic Blockade with Spinal Anesthesia on Uterine and Fetal Hemodynamies and Oxygen Consumption in the Sheep

“…A d m in istratio n of ganglionic blo ck in g ag en ts o r of sp in al an esth esia to p re g n a n t w om en p roduces a fall in blood p ressu re an d cardiac o u tp u t w hich is signif ic a n tly g re a te r th a n t h a t observ ed in n o n p re g n a n t su b jects [1]. T he m ark ed c irc u la to ry response o f th e p re g n a n t su b je c t h as been a t trib u te d to b lo ck ad e o f an o v eractiv e v e n o m o to r to n e, w hich, in tu r n , lead s to in creased c a p a c ity o f th e venous circu latio n an d to venous pooling [2], T he effects o f th e se c irc u la to ry a lte ra tio n s on u te rin e and fetal h em o d y n am ics a n d oxygen u tiliz a tio n have n o t been assessed. Iso la te d clinical o b serv atio n s h av e sug gested th a t th e h y p o ten sio n of spin al a n e sth e sia a n d th e d ru g s used to correct it m ig h t be d e tri m en tal to th e fe tu s [3], T hese s ta te m e n ts , how ever, h av e n o t been su p p o rte d b y e x p e rim e n ta l evidence.…”

Hemodynamic Effects of 1-Hydrazinophthalazine (Apresoline) in Human Pregnancy: Results of Intravenous Administration 1

“…As has been previously reported (16,17,18), ganglionic blocking agents induce only a negligible fall in blood pressure in patients with acute toxemia of pregnancy. In contrast, in normal pregnant women and frequently in pregnant patients with essential hypertension these drugs have a marked hypotensive effect, usually associated with a decrease in both cardiac output and renal plasma flow (19,20 With the exception of the four patients with convulsive tclampsia, who were studied upon admission, all the patients were at bed rest on the obstetric wards for at least 24 hours prior to the study. During this period, the spontaneous variations in blood pressure in the toxemic patients and those with essential hypertension were determined by sphygmomanometric readings every one or two hours, the pulse rate also being determined.…”