Risk Factors Of Hypoxemia In Patients Transferred To ICU After Surgery

Background and objectives:Hypoxemia is a common complication of perioperative patients,which can have adverse effects on their prognosis.For high-risk patients,timely transferred to the Intensive Care Unit(ICU)after surgery can prevent the deterioration of the condition and reduce mortality.However,current research on the factors influencing postoperative hypoxemia has mainly focused on patients in general wards or anesthesia recovery rooms,and little is known about the occurrence and influencing factors of hypoxemia in patients transferred to the ICU after surgery.Therefore,this study aimed to explore the occurrence and influencing factors of hypoxemia in patients transferred to the ICU after surgery and to provide reference for the prevention and management of postoperative hypoxemia.Materials and Methods:1.This retrospective study collected data from patients who underwent surgery and were transferred to the ICU at Shandong Provincial Hospital between June and September 2020.2.The collected data included demographic and clinical characteristics,surgical and anesthesia related information,sedative and analgesic medication,fluid management during ICU stay,and PaO2/FiO2 related information.3.Hypoxemia was defined as PaO2/FiO2 ≤300 mmHg(1 mmHg ≤0.133 kPa),according to the Noninvasive respiratory support in the hypoxaemic peri-operative/periprocedural patient:a joint ESA/ESICM guideline.This study observed the occurrence of hypoxemia on the day of transfer to the ICU,before extubation,and the second day after surgery and analyzed the risk and protective factors for hypoxemia at these three time points.4.All data were analyzed using SPSS 26.0 statistical software,and statistical methods used included independent-sample t-test,nonparametric tests,chi-square test,binary logistic regression,and receiver operating characteristic curve.Results:1.This retrospective study included 220 patients,and the incidence of hypoxemia on the day of transfer to the ICU was 40.5%(89/220),with a median duration of 4.0 hours(IQR:3.0-6.5 hours).The incidence of hypoxemia before extubation was 36.8%(81/220),with a median duration of 4.5 hours(IQR:3.5-6.8 hours).Eight patients developed new hypoxemia after extubation,with an incidence of 3.6%and a median duration of 3.0 hours(IQR:2.0-4.0 hours).In addition,eight patients had hypoxemia on the day of surgery,which lasted until the second day after surgery.The incidence of hypoxemia on the second day after surgery was 36.3%(77/212),with a median duration of 2.0 hours(IQR:1.5-2.8 hours).2.According to the binary logistic regression analysis,the independent risk factors for hypoxemia on the day of transfer to ICU after surgery include:body mass index(BMI)(OR=1.099,95%CI:1.014-1.191,P=0.021)and the American Association of Anesthesiologists(ASA)rating>2(OR=2.377,95%CI:1.290-4.379,P=0.005).While the protective factor is minimally invasive surgery(OR=0.522;95%CI:0.280-0.973;P=0.041).3.The results of this study show that the independent risk factors for hypoxemia before extubation after transferred to ICU include:BMI(OR=1.101,95%CI 1.013-1.196,P=0.024),ASA grade>2(OR=2.433,95%CI 1.236-4.786,P=0.010),intraoperative hypoxemia(OR=2.097,95%CI 1.105-3.979,P=0.024),dose of flurbiprofen in the surgical analgesia formula(OR=1.025,95%CI 1.010-1.041,P=0.001)and the intraoperative dexamethasone dose(OR=1.145,95%CI 1.051-1.248,P=0.002).While the protective factor is minimally invasive surgery(OR=0.374;95%CI:0.187-0.747;P=0.005).These results suggest that before extubation after transferred to ICU,attention should be paid to high BMI,higher ASA classification,intraoperative hypoxemia,high doses of flurbiprofen and dexamethasone.4.In addition,the independent risk factors for hypoxemia on the second day after surgery include:age(OR=1.048,95%CI:1.021-1.077,P=0.001),BMI(OR=1.129,95%CI:1.027-1.242,P=0.012),hypoxemia before extubation after transferred to ICU(OR=4.364,95%Cl:2.217-8.588,P<0.001),intraoperative esmolol(OR=3.799,95%CI:1.519-9.502,P=0.004),and sufentanil dose during ICU stay(OR=1.252,95%CI:1.079-1.453,P=0.003).These results suggest that on the second day after surgery,attention should be paid to high age,high BMI,hypoxemia before extubation after transferred to ICU,intraoperative esmolol,and high dose of sufentanil during ICU stay,in order to prevent and treat hypoxemia early.Conclusions:1.The incidence and duration of hypoxemia in patients transferred to the ICU after surgery are high,and the influencing factors for hypoxemia at different observation time points are different,indicating the need for strengthened monitoring and management.2.Patients undergoing minimally invasive surgery are less likely to develop hypoxemia after surgery.Patients with high BMI and ASA grade>2 are prone to hypoxemia on the day after surgery and need to be closely monitored and appropriate measures taken.Patients with high doses of flurbiprofen in surgical analgesia formulations and intraoperative dexamethasone are also prone to hypoxemia before tracheal extubation after transferred to ICU and should be used with caution.Patients with higher age,higher BMI,postoperative hypoxemia before extubation,intraoperative esmolol injection,and higher remifentanil doses in ICU are more likely to develop hypoxemia on the second day after surgery,and need to be closely monitored and managed.3.The preoperative lung function status of patients,surgical department,surgical duration,intraoperative fluid management,length of stay from ICU admission to extubation,and fluid management during ICU have no significant impact on postoperative hypoxemia in patients transferred to the ICU,and further research is needed.