Avoidance of unnecessary blood transfusions has always been a focus of clinical research. The rate of perioperative red blood cell transfusion in patients undergoing cardiac surgery under cardiopulmonary bypass reaches between 50-70%, and the intraoperative red blood cell transfusion rate is 30-50%. Regarding whether and when to perform a blood transfusion, it is necessary to comprehensively consider the benefits and risks brought by blood transfusion. Previous studies on blood transfusion strategies have mainly focused on the hemoglobin threshold, but the hemoglobin level does not fully reflect the level of tissue oxygenation. Mixed venous blood oxygen saturation has been widely studied as a valuable indicator reflecting the balance of oxygen delivery and oxygen consumption. But due to the difficulty of placing a pulmonary artery floating catheter for monitoring, its clinical application is limited. Central venous oxygen saturation requires only a small collection of blood samples, which can reflect the oxygen saturation of the superior vena cava, and studies have shown that it can effectively guide the blood transfusion of patients undergoing cardiac surgery. Existing studies have shown that in critically ill patients, the use of arterial-venous oxygen difference \> 3.7 mL as an indicator to guide blood transfusion can lead to a higher 90-day survival rate. However, the relationship between the arterial-venous oxygen difference and the incidence of adverse events in cardiac surgery patients under CPB remains unclear. Whether increasing the arterial-venous oxygen difference during surgery can reduce the incidence of postoperative adverse events remains to be clarified. This study intends to collect intraoperative arterial blood and central venous blood samples from cardiac surgery patients undergoing CPB, and analyze the relationship between arterial-venous oxygen difference and the incidence of postoperative adverse events.
The \>18 y/o patients who undergo cardiac surgery with cardiopulmonary bypass and with a preoperative additive EuroSCORE I≥ 6 are enrolled. Blood samples will be collected through arteries and central venous at the following intraoperative time points: before CPB, during CPB, and after CPB. The observation will end by hospital discharge or 28 days after surgery, whichever came first. The follow-up will continue for one year after surgery.
Study Type
OBSERVATIONAL
Enrollment
314
No intervention
The Second Affiliated Hospital of Zhejiang University anesthesiology department
Hangzhou, Zhejiang, China
Composite outcome of mortality and serious morbidity (cardiac, renal, and neurological events)
Composite incidence of any one of the following events occurring during the hospitalization : (1) all-cause mortality; (2) myocardial infarction; (3) new renal failure requiring dialysis; or (4) new focal neurological deficit (stroke)
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Incidence of any independent component of the primary outcome
Incidence of any independent component of the primary outcome (all-cause mortality, myocardial infarction, new renal failure requiring dialysis, and new focal neurological deficit (stroke))
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Blood product transfusion
Time, category, and volume of blood product transfusion
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Length of stay in ICU
Length of stay in ICU after surgery
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Total length of hospital stay after surgery
Total length of hospital stay after surgery
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Duration of mechanical ventilation after surgery
Total length of hospital stay after surgery
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Occurrence of low cardiac output after surgery
Need for two or more inotropes for 24 hours or more, intra-aortic balloon pump postoperatively or ventricular assist device
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Infection
Infection will be defined as septic shock with positive blood cultures; pneumonia defined as autopsy diagnosis or roentgenographic infiltrate and at least two of the following three criteria: fever, leukocytosis, and positive sputum culture; and/or deep sternal or leg wound infection requiring intravenous antibiotics and/or surgical debridement
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Gut infarction
confirmed by imaging, autopsy, or through surgical means
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Acute kidney injury
AKI defined by the KDIGO
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Seizures
Defined as generalized or focal tonic-clonic movements consistent with seizure; or EEG demonstrating epileptiform discharges; or diagnosis of seizures by neurologist or neurosurgeon consultation
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Delirium
Based on one of the following criteria: CAM-ICU/ CAM (even on 1 occasion) or ICDSC \> 3 or more than one dose of haloperidol or similar antipsychotic drug or documented delirium by neurologist or neurosurgeon or psychiatrist consultation
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Encephalopathy
Defined as unexpected delayed awakening or severely altered mental status (unconscious despite no sedative medication for more than 5 days), or encephalopathy documented by neurologist or neurosurgeon or psychiatrist consultation
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
Reoperation rate
The rate of reoperation
Time frame: From the start of surgery until hospital discharge or postoperative day 28, whichever comes first
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