Does spinal anesthesia cause hypotension via decreased stroke volume or systemic vascular resistance in elderly patients, and does bupivacaine dosage affect this?
Spinal anesthesia-induced hypotension in elderly patients is primarily driven by a reduction in stroke volume rather than systemic vascular resistance, independent of bupivacaine dose (10 vs 15 mg).
CO and blood pressure decreased significantly after the onset of SA in elderly patients. This is mainly caused by a decrease in SV and not by a decrease in SVR. There was no difference in CO and blood pressure change between dosages of 10 or 15 mg bupivacaine.
Hofhuizen et al. (Fri,) studied this question.