Study of plasma neuropeptide Y (NPY) and catecholamines levels during spinal anesthesia.

Plasma levels of neuropeptide Y (NPY) and catecholamines were investigated during spinal anesthesia. Ten ASA physical status I-II patients were studied after obtaining institutional approval and informed contents. All patients were free from endocrine and metabolic disease underwent elective low risk operation. No premedication was given before operation. Spinal anesthesia was performed on lateral position from L3-4 interspace with 15 mg tetracaine without added epinephrine. The analgesic level was about at T6 dermatone. Blood samples were obtained from radial artery catheter, 15 minutes before spinal anesthesia and 5', 15', 30', 60', 120', during operative period and 30' after operation in postanesthesia recovery room. The results showed that there were significant elevation in plasma level of NPY during spinal anesthesia compared with the level before anesthesia. However, no statistically significant changes of plasma catecholamines were found.