The Clinic Study On Perioperative Autonomic Nervous Function In The Elderly

> [BACKGROUND AND PURPOSE] In recent years, there werelots of reports that autonomic nervous systera(ANS) was involved in many cardiac pathological and physiological processes. Many cardiac aberrant events, such as heart failure, cardiac arrhythmia, myocardiac ischemia or myocardiac infarction, were accompanied bythe subsidence or/and unbalance of autonomic nervous tone. Simultaneously, the neuroendocrine systems such as catecholamine and renin-angiotensin were generally activated. During this process, ?-adrenergic receptor (?-AR) had played a crucial intermediary role. The aim of this study was to investigate changes of perioperative autonomic nervous function and their pathological and physiological mechanisms by HRV analysis and measurement of density and function ofP-AR.> [METHODS] 20 ASA I ~IIadult patients, undergoing elective thoracic or ventral surgery under general anesthesia, were assigned into two groups by ages, i. e.the old group (age^GO, n=10) and the young group (age<60, n=10). While changes of each component of HRV analysis in the frequencydomain in five minutes were observed , the venous blood samples were drawn out to isolate lymphocytes and stored under -20癈 to measure plasma catecholamine level during the different perioperative periods, i. e. before the surgery, after the general anesthesia, at the waking time and 1,3,7 day after the surgery. Density of P -adrenergic receptor (Bmax) and isoproterenol-stimulated cAMP product in lymphocytes were measured respectively with radioligand binding assay and radioimmunoassay (RIA) at the different time points of perioperative periods. Epinephrine(E) and norepinephrine (NE) in the plasma were also measured with RIA. [RESULTS] Compared with the baselines before the surgery, total power(TP) of HRV, together with high-frequency (HF) power, low-frequency(LF) power and very-low-frequency (VLF)power, decreased significantly after the general anesthesia and surgery. They didn't return the baselines untill one week after the surgery. TP, HF, LF in old group were decreased more significantly than those in young group during the perioperative periods, especially after the general anesthesia. Plasma level of E and NE in both groups increased significantly after the surgery, not returning the baselines untill 3 and 7 day after the surgery respectively. Moreover, plasma E and NE in old group were significantly higher after the surgery than those in young group. Bmax in both groups decreased significantly within one week after the surgery, especially in old group. The isoproterenol-stimulated cAMP product in lymphocytes had significantly decreasedas early as after the general anesthesia and didn' t return the baselines until one week after the surgery. Also, cAMP product in old group was decreased more significantly than that in young group during the most perioperative periods. Excluding the effects of general anesthesia, Plasma NE inversely correlated with isoproterenol-stimulated cAMP product while TP positively correlated with cAMP during the perioperative periods.> [ CONCLUSIONS ] ?The autonomic nervous function in patients was badly damaged after the anesthesia and surgery, especially in old group. (2) ?-AR generally appeared desensitization and downregulation one week during the perioperative periods, especially in the elderly. This had relations with general anesthestic drugs and plasma catecholamine level concentration.?HRV in human, especially in the elderly, significantly decreased one week after the general anesthesia and surgery. This had relations with the downregulation and desensitization of 3 -AR. ?HRV analysis is simple and feasible, and can preferably monitor the autonomic nervous function in human during the perioperative periods.