Relationship between propofol anesthesia and postoperative delirium and inflammatory responses of aged rats / 中华麻醉学杂志

ABSTRACT

Objective To evaluate the relationship between propofol anesthesia and postoperative delirium and inflammatory responses of aged rats.Methods Twenty-four adult male Sprague-Dawley rats,aged 18 months,weighing 550-650 g,were divided into 3 groups (n=8 each) using a random number table method:control group (group C),propofol anesthesia for 2 h group (group P2) and propofol anesthesia for 4 h group (group P4).In P2 and P4 groups,anesthesia was maintained with propofol at a rate of 24 mg· kg-1 · h-1 for 2 and 4 h,respectively,after anesthesia was induced with propofol.Morris water maze test was performed at 1 day before and after anesthesia.Blood and cerebrospinal fluid samples were collected after the end of Morris water maze test for determination of interleukin-1beta (IL-1β),IL-4,IL-6 and tumor necrosis factor-alpha (TNF-α) concentrations in plasma and cerebrospinal fluid by enzyme-linked immunosorbent assay.The hippocampus and cortex were removed for determination of Iba-1 positive cells.Results Compared with group C and the baseline value before anesthesia,no significant change was found in the escape latency or percentage of time of staying at the original platform quadrant in P2 and P4 groups (P＞0.05),the concentrations of IL-6 in cerebrospinal fluid and TNF-α in plasma were significantly decreased in group P2,the concentrations of IL-1β in cerebrospinal fluid and IL-4,IL-6 and TNF-α in plasma were significantly increased,and the concentrations of IL-1β in plasma and IL-4 in cerebrospinal fluid were decreased in group P4,and the number of hippocampal Iba-1 positive cells were significantly decreased in P2 and P4 groups (P＜0.05 or 0.01).Conclusion Propofol anesthesia dose not induce postoperative delirium and central inflammatory responses within 4 h,and propofol can induce peripheral inflammatory responses when anesthesia time is longer than 2 h.