Effect Of Hydrogen Inhalation On Postoperative Cognitive Dysfunction In Elderly Orthopaedic Patients

Backgroud Postoperative cognitive dysfunction(POCD)is a kind of disease with cognitive function change including unable to concentrate the attention,memory decline,etc,and even seriously personality and social behavior ability decling,which is main clinical manifestation as cognitive impairment,anxiety,memory impairment,and language comprehension and social integration ability degerenation.It is not only prolonging patients hospital stay and increasing hospital costs and postoperative mortality,but also triggerring a series of medical,social and economic problems.The etiology and pathogenesis of POCD is still unclear,but a growing number of studies suggest that inflammation may play a very important role.Hydrogen gas is a new type of gas signal molecule,with a number of roles,sush as: anti-inflammatory,antioxidant,anti-apoptosis and signal conditioning to protecte nervous system from damage.This study intends to observe whether hydrogen gas suction couldreduce the happening of POCD of the old orthopaedic patients and findits possible mechanism,which will provide theoretical basis for its prevention and treatment of POCD.Objective To investigate effect of hydrogen inhalation on postoperative cognitive dysfunction in elderly orthopaedic patients and its mechanism.Methods Forty-four patients of both sexes,aged 75 yr or higer,of ASA physical status?or?,scheduled for elective orthopedic operation under intraspinal anesthesia,were randomly divided into 2 groups: control group(group C)and Hydrogen gas inhalation group(group H).Before anesthesia and surgery,Group H people was immediately given the mixed gas containing 66.6% hydrogen and 33.3% oxygen inhalation for 60 min,while group C was given 33.3% oxygen inhalation for 60 min.The arterial blood gas was determinated respectively at hydrogen gas suction for0min(H1),30min(H2)and 60min(H3).All persons were assessed and recognized as without preoperative cognitive dysfunction by mini-mental state examination(MMSE).To evaluate the incidence of cognitive dysfunction(MMSE<24 was consideredd as POCD),the cognitive function scores of each one were recorded at the preoperative day(M1),the postoperative day 1(M2),3(M3),and 7(M4).Then,artery blood samples were collected at prior to hydrogen inhalation(T1),immediately after surgery(T2),postoperative 3 h(T3),postoperative 6 h(T4)to detect levels of interleukin 6(IL-6)and superoxide dismutase(SOD).Results There was no statistical difference between general condition of each index,operation time and blood loss of two groups(P > 0.05).High concentrations of hydrogen inhalation did no affect the oxygenation function of patients,because comparing the two groups has no statistical significant(P > 0.05).The incidence of POCD of patients in group H at M2,M3,and M4 were 23.3%,10% and 3.3%,respectively,were less than group C(33.3%,16.7% and 8.3%),but no statistical difference was found between two groups(P > 0.05).Compared with T1,levels of IL-6 in both group at T3,T4 increased significantly,while levels of SOD activity decreased obviously(P < 0.05);Compared with group C,the level o f IL – 6 of patients in the H group at T2-T4 was obviously reduced,but SOD activity significantly increased(P<0.05).Conclusion Hydrogen inhalation could reduce postoperative cognitive dysfunction in elderly orthopaedic patients and its mechanism may be related to control inflammation and oxidative stress.