The Effect Of OLV On RSO₂and The Correlation Between RSO₂and POCD In Older Patients During OLV Undergoing Esophagectomy

Part1:The changes and influencing factors in regional cerebral oxygen saturation during OLV Undergoing esophagectomyObjective To study both the changes and influencing factors in regional cerebral oxygen saturation (rSO2) during OLV in older patients undergoing esophagectomy.Methods20esophageal cancer patients,ASA Ⅱ～Ⅲ grade, age≥65years old, undergoing esophagectomy and necessitating OLV were randomly selected, Left double-lumen endotracheal tube was used for OLV, INVOS5100Cerebral Oximeter was used to measure regional cerebral oxygen saturation (rSO2) from the awake state to extubation phase, For intraoperative hemodynamic and respiratory managements,systolic blood pressure was maintained at≥80mmHg, fluctuation range≤20%, SpO2≥95%, ETCO235～40mmHg, the bispectral index (BIS)40～55, Other standard monitoring parameters and blood gas (ABG) analysis was observed and recorded at the corresponding time points.Results①n the awake state and supine position without O2inhalation (T1),patients showed a regional cerebral oxygen saturation (rSO2) of (66.9±6.2)%[60%-73%, median67%],Which increased to maximum(79.8≈4.8)%[78%-84%, median81%] after anesthesia induced and supine position with two lung ventilation by FiO2100%(SP-TLV,T2), During TLV in lateral decubitus(LD-TLV,T3) rSO2decreased to (75.5±6.6)%[71%-82%, median77%], When OLV in lateral decubitus(LD-OLV,T4) rSO2decreased to a minimum value of (66.2±8.6)%[60%-75%, median66%], which recover to (75.8±7.1)%[71%-83%, median78%]after extubation in supine position with TLV (SP-TLV,T5); Baseline rSO2was defined as the highest rSO2value obtained in supine position with two lung ventilation by FiO2100%(SP-TLV,T2),During LD-OLV (T4), all patients had decrease of more than10%of the baseline rSO2(SP-TLV,T2), The percent change from baseline rSO2was (-18.2±7.9)%,40%(8/20) of patients had a decrease of more than20%of the baseline rSO2,15%(3/20) of patients had a decrease of more than25%of the baseline rSO2;Compared to SP-TLV(T2),the changes of rSO2in LD-TLV(T3) less than5%.②The changes in rSO2was not correlated with lateral decubitus and any standard clinical monitoring parameters,which include BIS, SpO2, MAP, body temperature, PaCO2, PaO2, Hct, Hgb, SaO2(P>0.05)Conclusions Significant changes in regional cerebral oxygen saturation (rSO2) occurred during OLV in older patients undergoing esophagectomy, The percent change from baseline rSO2was (-18.2±7.9)%,40%of patients had a decrease of more than20%of the baseline rSO2, The changes rate in rSO2observed during OLV was not correlated with lateral decubitus and any standard clinical monitoring parameters. Part2:The correlation between the changes of regional cerebral oxygen saturation during OLV and POCD in older patients undergoing esophagectomyObjective To study the correlation between the changes of regional cerebral oxygen saturation (rSO2) during OLV and POCD in older patients undergoing esophagectomy.Methods Seventy-eight esophageal cancer patients were randomly selected to participated in this study, ASA Ⅱ～Ⅲ grade, age≥65years old, each of whom received general anesthesia and OLV using left double-lumen endotracheal tube undergoing esophagectomy, INVOS5100B (Somanetics, Troy, MI, USA) Cerebral Oximeter was used to measure regional cerebral oxygen saturation (rSO2) from the awake state to extubation phase, For intraoperative hemodynamic and respiratory managements,systolic blood pressure was maintained at>80mmHg, fluctuation range≤20%, SpO2≥95%, ETCO235～40mmHg, the bispectral index (BIS)40-55, Other standard monitoring parameters and arterial blood gas (ABG) analysis was observed and recorded at the corresponding time points,all patients take PICA for analgesia and VAS to value effects. Cognitive function was assessed using the mini mental state examination (MMSE) at the time2h preoperatively(baseline) and then repeated at4days postoperatively, any patient showing MMSE decline by more than or equal to one standard deviation of the pre-operative baseline value was defined as having POCD,The patients enrolled were classified into two groups:with (group POCD) and without (non POCD group) POCD. The rSO2desaturation score was calculated by multiplying rSO2below65%by time(seconds). Multivariate logistic regression models were used to assess POCD and the rS02desaturation score.Results Sixty-four patients undergoing esophagectomy enrolled in the study, Sixteen patients were included in group POCD(25.0%,16/64), Baseline rSO2was defined as the highest rSO2value obtained in supine position with two lung ventilation by FiO2100%(SP-TLV,T2), in this study the baseline rSO2was (79.4±4.6)%,39.1%(25/64) of patients had a decrease of more than20%of the baseline rSO2,15.6%(15/64) of patients had a decrease of more than25%of the baseline rSO2;There are37.5%(24/64) of the patients who rSO2value less than65%during OLV, There are23.4%(15/64) of the patients who rSO2value less than60%during OLV. There are statistically significant difference in the age between POCD group and non-POCD group (P<0.05).The POCD significantly correlates with the rSO2desaturation score (P<0.05). There are no statistically significant difference between POCD group and non-POCD group with gender ratio,weight,ASA grade,anesthesia time,OLV time,education degree, History of hypertension and diabetes, History of myocardial infarction or strokes, Intraoperative blood loss, minimum oxygen partial pressure and systolic blood pressure in the intraoperative postoperative analgesia VAS score, postoperative respiratory complications,et al (P>0.05)Conclusions Higher incidence of POCD in older patients undergoing esophagectomy. There are statistically significant difference in the age between POCD group and non-POCD group.The POCD significantly correlates with the rSO2desaturation score. Part3:Efficacy of lung protective ventilation regimen on regional cerebral oxygen saturation during OLV Undergoing esophagectomyObjective To investigate the efficacy of lung protective ventilation regimen on regional cerebral oxygen saturation (rSO2) during OLV in older patients undergoing esophagectomy.Methods Forty esophageal cancer patients participated in this study, age≥65years old,each of whom received general anesthesia and OLV using double-lumen endotracheal tube, were randomly divided into protective ventilation regimen group(PV)(n=20)and conventional ventilation group(CV)(n=20).In group PV,all patients received two-lung ventilation(TLV)and one-lung Ventilation (OLV) with tidal volume(VT) of6ml/kg with PEEP5cmH20,I:R=1:2;In group CV, all patients received TLV and OLV with VT of10ml/kg without PEEP,I:R=1:2. Regulating breathing frequency to maintain ETCO2at35-45mmHg during TLV and OLV. rSO2was measured using INVOS5100B(Somanetics, Troy, MI, USA) from the awake state to extubation phase, For intraoperative hemodynamic and respiratory managements,systolic blood pressure was maintained at≥80mmHg, fluctuation range≤20%, SpO2≥95%, ETCO235～40mmHg, the bispectral index (BIS)40-55, The rSO2desaturation score was calculated by multiplying rSO2below65%by time(seconds),which was calculated by the following formula:rSO2score=[65%rSO2-current rSO2(%)]×time (seconds). The rSO2desaturation score generated is an area under the curve measurement, which accounts for both depth and duration of desaturation below the65%saturation threshold. Arterial blood samples were taken before induction of anesthesia(T1) and at10min of TLV(T2) and30min of OLV (T3)for blood gas analysis. Qs/Qt was calculated, standard monitoring parameters was observed and recorded at the corresponding time points.Results①Fourty patients undergoing esophagectomy enrolled in the study, in the awake state and supine position without O2inhalation (T1),patients showed a regional cerebral oxygen saturation (rSO2) of (65.4±3.3)%and (66.7±3.1)%in group CV and group PV, During TLV10min in lateral decubitus(T2) rSO2increased to (76.1±4.6)%and (77.3±3.1)%in group CV and group PV, When OLV30min in lateral decubitus(T3) rSO2decreased to (66.5±5.2)%和(68.8±5.8)%in group CV and group PV.②Patients with rSO2desaturation score greater than3,000%-second respectively was15%(3/20) in group PV and30%(6/20)in group CV, there was significantly lower in group PV than that in group CV(P<0.05).③The PaO2,Qs/Qt,rSO2at T2and T3was higher than Tl in group CV and PV (P<0.05);Compared to T2,the PaO2,rSO2in T3was lower, the Qs/Qt was higher (P<0.01);Compared to group CV,the PaO2,rSO2at T3in group PV were higher,though Qs/Qt was lower (P<0.05).④There was no significant difference with other monitoring parameters between two groups,which include BIS, SpO2, MAP, body temperature, PaCO2, Hct, Hgb, SaO2(P>0.05)Conclusions Protective ventilation regimen can improve the Oxygenation and reduce Pulmonary shunt during OLV in older patients undergoing esophagectomy,and help to reduce the incidence of cerebral desaturation.