Effects Of Different Levels Of Intraoperative Blood Pressure Regulation On Postoperative Delirium In Elderly Patients Undergoing Hip Replacement

AIM:Postoperative delirium?POD?is defined as an acute?and fluctuating?disturbance in attention and cognition,which is not based on a pre-existing neurocognitive disorder.Postoperative delirium usually occurs 1-3 days after surgery,mostly in elderly patients.Intraoperative blood pressure is an important factor influencing postoperative delirium,while regional cerebral oxygen saturation?r SO₂?is an indicator of cerebral oxygen supply and oxygen metabolism,which can effectively predict postoperative delirium.The aim of this study was to compare the effects of different blood pressure management strategies on regional cerebral oxygen saturation and postoperative delirium.METHODS:150 patients of both sexes,male54 cases,female 78 cases,aged 65-80 years,falling into ASA physical status?or?,scheduled for elective hip replacement under general anesthesia,were divided into three groups using a random number table:MAP was maintained 10%?20%below the baseline?Group A?,MAP was maintained within 10%lower than the baseline?Group B?,and MAP was maintained within 10%higher than the baseline?Group C?.After anesthesia induction,laryngeal mask airway?LMA?was inserted in the patients for mechanical ventilation,with Fi O₂60%,oxygen flow 2 L/min,VT 8 ml/kg,RR10?14 beats per minute,I:E 1:2,and P_ETCO₂35?45 mm Hg were maintained.The operative time,anesthesia time,infusion volume,bleeding volume,waking time,extubation time and use of vasoactive drugs were recorded.Mean blood pressure?MAP?,heart rate?HR?,bilateral average cerebral oxygen saturation?r SO₂?,bispectral index?BIS?and Pa CO₂were recorded before the induction of anaesthesia?T₀?,5 min after induction of anaesthesia?T₁?,5 min,30 min,60 min after incision?T₂-T₄?,at the end of surgery?T₅?,and 5 min after surgery?T₆?.Confusion Assessment Method-Chinese Reversion?CAM-CR?was used to record the occurrence of postoperative delirium and VAS score 1-3 days after surgery.The number of analgesic pump compressions within 48h after surgery,stay time of PACU,hospital stay,postoperative complications were recorded.RESULTS:1.The preoperative basic information of the patient:There was no significant difference in preoperative basic clinical information?including gender,age,BMI,ASA,et al?,surgery duration,anesthesia duration,fluid volume and total blood loss in the three groups?P>0.05?.2.The change of vital signs:Compared to T₀,r SO₂values at T₂-T₆were statistically significant?P<0.05?.Compared with group C,intraoperative r SO₂values were increased at T₂-T₆in group A and group B?P<0.05?.Compared with T₀,BIS values at T₂-T₆significantly decreased?P<0.05?.Compared with T₀,Pa CO₂values at T₆significantly increased in group A?P<0.05?.Compared with T₀,Pa CO₂values at T₅-T₆significantly increased in group B?P<0.05?.Compared with T₀,Pa CO₂values at T₅significantly increased in group C?P<0.05?.There was no statistical difference in the BIS and Pa CO₂valve among the three groups.3.Comparison of the important standard at each time point in the three groups:There were 10 cases of postoperative delirium in group A,8 cases in group B and 1 case in group C.The overall incidence of postoperative delirium was 12.7%,with 10%in group A,8%in group B and 2%in group C.Compared with group C,the CAM-CR score of group A and group B significantly increased on the 1st and 2nd day after surgery?P<0.05?.4.Comparison of the secondary outcome in the three groups.?1?There was no significant difference in the dosage of phenylephrine,the use of urapidil,esmolol and atropine in the three groups.There was no significant difference in the dosage of propofol and remifentanil in the three groups.?2?There were no statistically significant differences among the three groups in surgery duration,anesthesia duration,MAP maintenance time,infusion volume,total blood loss,analgesic pump compression times within 48 hours,and VAS score 1-3days after surgery.?3?Compared with group C,the incidence of postoperative delirium and awake agitation in groups A and B were significantly increased?P<0.05?.?4?The incidence of postoperative nausea and vomiting?PONV?and fever was not significantly different among the three groups.Conclusion Intraoperative blood pressure was maintained within 10%higher than the baseline,which helps to reduce the incidence of postoperative delirium and emergence agitation,shorten the length of PACU stay and hospital stay,and may be related to increased cerebral oxygen saturation during surgery.