[The role of melatonin in the immediate postoperative period in elderly patients]. / Il ruolo della melatonina nell'immediato decorso postoperatorio dei pazienti anziani.

ABSTRACT

BACKGROUND: Melatonin induces sleep and modulates immune system. Aim of the paper is to show a possible relation between impaired rhythm of melatonin secretion and the onset of postoperative septic complications and insomnia in old patients undergoing surgery. METHODS: Fifty old patients, aged from 60 to 94 years, have been studied; 39.5% of the patients had neoplastic disease. Melatonin serum levels have been evaluated by ELISA technique at 12 p.m., 3 a.m. 8 a.m. immediately before operation. Postoperative clinical findings of insomnia and septic complications have been recorded. RESULTS: The melatonin serum mean values of all the patients were 16.3 pg/ml at 12 p.m., 22.4 pg/ml at 3 a.m. and 7.1 pg/ml at 8 a.m. Neoplastic patients showed the higher values of melatonin (26.696 pg/ml, 33.143 pg/ml, 9.185 pg/ml), long-lived patients (> 90 years) the lower. The melatonin secretion curve of the old patients with postoperative insomnia (19.961 pg/ml, 20.297 pg/ml, 9.378 pg/ml) or postoperative septic complications (20.695 pg/ml, 16.183 pg/ml, 6.036 pg/ml) was significantly different compared with that of other patients. The peak was advanced, lower and decreased slowly in the midnight. CONCLUSIONS: The study seems to show a possible correlation between impaired rhythm of melatonin secretion and postoperative insomnia and postoperative sepsis in old patients undergoing surgery.