Remote Ischemic Preconditioning on Pulmonary Injury in Cardic Surgery

Effect of Remote Ischemic Preconditioning on Pulmonary Injury in Cardic Surgery

During cardiac surgery with cardiopulmonary bypass , pulmonary dysfunction remains to be a problem complicating the postoperative course of the patients.Remote ischemic preconditioning(RIPC) with transient upper limb ischemia/reperfusion is a novel, simple, cost-free,non-pharmacological and non-invasive strategy.Recent several trials suggested that RIPC could provide pulmonary protection by reducing serum biomarkers,however,whether the RIPC can improve the clinical outcomes in patients undergoing on-pump cardiac surgery,is still uncertain.

The study hypothesis is: remote ischemic preconditioning will provide lung-protective effect and improve clinical outcomes in patients undergoing cardic surgery.

Remote ischemic preconditioning (RIPC) protocol will be induced during anesthesia by 3 cycles of 5-min upper limb ischemia and 5-min reperfusion using a blood pressure cuff inflated to a pressure 200mmHg

Inclusion Criteria:

1. Patients undergoing heart surgery on cardiopulmonary bypass
2. Patients aged 18 years to 80 years

Exclusion Criteria:

1. Inability to give informed consent
2. Preoperative severe impairment of respiratory function (arterial oxygen tension (PaO2) <60 mmHg or FEV1<50% predicted)
3. Prior receipt of chemotherapy or radiation therapy or immunotherapy
4. left ventricular ejection fraction less than 30%
5. preoperative use of inotropics or mechanical assist device
6. Patients with significant hepatic dysfunction (Prothrombin>2.0 ratio)
7. Patients with known renal failure with a GFR<30 mL/min/1.73 m2
8. recent myocardial infarction (within 7 days)
9. Systemic or local active infections (either clinically defined or suggested by evidence such as elevated C-reactive protein levels, leukocytosis, or a body temperature>38℃)
10. Significant peripheral arterial disease affecting the upper limbs
11. surgeries: cardiac transplantation, concomitant carotid endarterectomy , previous heart surgery,, off-pump surgery, emergency surgery