The Study Of Hypercapnia And Postoperative Cognitive Function In The Treatment Of Airway Intervention

Objectives The principal objectives of this dissertation are to understand the influence of hypercapnia on postoperative cognitive function.Methods A total of 221 ASAI-III patients without the medical history of any obvious neuropsychic and psychoneurotic diseases(aged 20-65 years)were studied during general anesthesia with rigid bronchoscope intervention.When the condition of the patients became steady half an hour after the start of the surgeries,their arterial blood was drew for arterial blood gas analysis(ABG).1)The patients were divided into two groups according to the assessment of the interview from one to three days after the surgery by Confusion assessment method-Chinese revision(CAM-CR),one group with the occurrence of POD(the POD group)and the other without the occurrence of POD(the control group).2)At the time points of one day before and seven days after the surgeries,the cognitive function of the patients was measured by Mini-Mental state examination(MMSE)and Montreal Cognitive Assessment(Mo CA).The patients were divided into two groups according to the partial pressure of carbon dioxide(Pa CO2)in ABG,the control group with Pa CO2≤45mm Hg and the hypercapnia group with Pa CO2>45mm Hg.Results 1 The POD group indicated no significant difference(P>0.05)in sex,educational status,body weight,chronic complications and pathogenic types.The age of the POD group was significantly higher than the control group(P<0.05),which was in accordance with the established conclusion that advanced age was a risk factor for POD.2 The operative time and the recovering time of the POD group were relatively longer than that of the control group(P<0.05).In terms of ABG results,the Pa CO2 of the POD group was significantly higher than that of the control group(P<0.05)and Pa O2 significantly lower(P<0.05),while there was no difference in the analysis of K+,Glu and Lac between the two groups(P>0.05).3 In the result of Logistic regression analysis,age,operative time and operative Pa O2 were independent factors for POD(P<0.05),among which age and operative time were risk factors(B>0)while operative Pa O2 was protective factor(B<0).Operative Pa CO2 was not an independent factor for POD(P>0.05).4 There were no significant difference between the hypercapnia group and the control group in age,sex,body weight,anesthesia duration,educational status,chronic complications and operative history of pulmonary lobectomy(P>0.05).The recovering time for the hypercapnia group was longer than that of the control group(P<0.05),which was consistent with the previous research finding that hypercapnia generated delayed emergence.5 The performance of the hypercapnia group in MMSE moderately improved after surgery(P<0.05).However,there existed no difference between the marks of the hypercapnia group and the control group after surgery(P>0.05).The Mo CA evaluation of the hypercapnia group improved after surgery(P<0.05)and the mark was even higher than the mark of the control group after surgery(P<0.05).6 In terms of the measurement of the cognitive test of each section,the hypercapnia group indicated higher visual spatial ability and execution score(P<0.05)and higher delayed recall ability score(P<0.05)after surgery than before surgery.Conclusions 1 Mild hypercapnia might probably not lead to the occurrence of POD of the patients under the treatment of bronchoscope intervention.2 In treatment using bronchoscope intervention,mild hypercapnia might ameliorate the early cognitive function of the patients in visual spatial ability and execution and delayed recall ability after surgery.