Muscular tissue desaturation and pneumonia in patients receiving lung cancer surgery:a cohort study

Background:Post-operative pneumonia(POP)is a common complication of lung cancer surgery,and muscular tissue oxygenation is a root cause of post-operative complications.However,the association between muscular tissue desaturation and POP in patients receiving lung cancer surgery has not been specifically studied.This study aimed to investigate the potential use of intra-operative muscular tissue desaturation as a predictor of POP in patients undergoing lung cancer surgery.Methods:This cohort study enrolled patients(≥55 years)who had undergone lobectomy with one-lung ventilation.Muscular tissue oxygen saturation(SmtO_(2))was monitored in the forearm(over the brachioradialis muscle)and upper thigh(over the quadriceps)using a tissue oximeter.The minimum SmtO_(2)was the lowest intra-operative measurement at any time point.Muscular tissue desaturation was defined as a minimum baseline SmtO_(2)of<80%for>15 s.The area under or above the threshold was the product of the magnitude and time of desaturation.The primary outcome was the association between intra-operative muscular tissue desaturation and POP within seven post-operative days using multivariable logistic regression.The secondary outcome was the correlation between SmtO_(2)in the forearm and that in the thigh.Results:We enrolled 174 patients.The overall incidence of muscular desaturation(defined as SmtO_(2)<80%in the forearm at baseline)was approximately 47.1%(82/174).The patients with muscular desaturation had a higher incidence of pneumonia than those without desaturation(28.0%[23/82]vs.12.0%[11/92];P=0.008).The multivariable analysis revealed that muscular desaturation was associated with an increased risk of pneumonia(odds ratio:2.995,95%confidence interval:1.080-8.310,P=0.035)after adjusting for age,American Society of Anesthesiologists status,Assess Respiratory Risk in Surgical Patients in Catalonia score,smoking,use of peripheral nerve block,propofol,and study center.Conclusion:Muscular tissue desaturation,defined as a baseline SmtO_(2)<80%in the forearm,may be associated with an increased risk of POP.Trial registration:No.ChiCTR-ROC-17012627.

Intraoperative body temperature and emergence delirium in elderly patients after non-cardiac surgery:A secondary analysis of a prospective observational study

Background:Emergence delirium(ED)is a kind of delirium that occured in the immediate post-anesthesia period.Lower body temperature on post-anesthesia care unit(PACU)admission was an independent risk factor of ED.The present study was designed to investigate the association between intraoperative body temperature and ED in elderly patients undergoing non-cardiac surgery.Methods:This study was a secondary analysis of a prospective observational study.Taking baseline body temperature as a reference,intraoperative absolute and relative temperature changes were calculated.The relative change was defined as the amplitude between intraoperative lowest/highest temperature and baseline reference.ED was assessed with the confusion assessment method for intensive care unit at 10 and 30 min after PACU admission and before PACU discharge.Results:A total of 874 patients were analyzed with a mean age of 71.8±5.3 years.The incidence of ED was 38.4%(336/874).When taking 36.0°C,35.5°C,and 35.0°C as thresholds,the incidences of absolute hypothermia were 76.7%(670/874),38.4%(336/874),and 17.5%(153/874),respectively.In multivariable logistic regression analysis,absolute hypothermia(lowest value<35.5°C)and its cumulative duration were respectively associated with an increased risk of ED after adjusting for confounders including age,education,preoperative mild cognitive impairment,American Society of Anesthesiologists grade,duration of surgery,site of surgery,and pain intensity.Relative hypothermia(decrement>1.0°C from baseline)and its cumulative duration were also associated with an increased risk of ED,respectively.When taking the relative increment>0.5°C as a threshold,the incidence of relative hyperthermia was 21.7%(190/874)and it was associated with a decreased risk of ED after adjusting above confounders.Conclusions:In the present study,we found that intraoperative hypothermia,defined as either absolute or relative hypothermia,was associated with an increased risk of ED in elderly patients after non-cardiac surgery.Relative hyperthermia,but not absolute hyperthermia,was associated with a decreased risk of ED.Registration:Chinese Clinical Trial Registry(No.ChiCTR-OOC-17012734).