Incidence and Risk Factors of Peri-operative Stroke in Non-cardiac,Non-neurosurgical Surgeries (POSIC)

• perioperative stroke occurs during and within 30 days after surgery. [ Time Frame: 30 days after suegery ] [ Designated as safety issue: No ]
  The primary outcome is perioperative stroke occurs during and within 30 days after surgery. This is defined as cerebral infarction or hemorrhage on computer tomography or magnetic resonance scan, or new neurological signs (paralysis, weakness or speech difficulties) lasting more than 24 hours or leading to death. The mechanism of stroke will be classified using the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria.
  
  

• total mortality and other major vascular complications up until 30 days after surgery [ Time Frame: 30 days after suegery ] [ Designated as safety issue: No ]

  Secondary outcomes include total mortality and other major vascular complications up until 30 days after surgery:

  1. Myocardial infarction is defined according to recent universal definition of myocardial infarction;
  2. Nonfatal cardiac arrest is a successful resuscitation from either documented or presumed ventricular fibrillation or sustained ventricular tachycardia or asystole;
  3. Pulmonary embolism;
  4. Congestive heart failure is defined by both clinical and radiographic evidence;
  5. Clinically significant atrial fibrillation is defined as atrial fibrillation that results in angina, congestive heart failure, symptomatic hypotension, or that requires treatment with a rate controlling drug, antiarrhythmic drug, or electrical cardioversion;
  6. Cardiac death: defined as any death with a cardiovascular cause, including deaths following a cardiovascular procedure, cardiac arrest, myocardial infarction, pulmonary embolus, stroke, hemorrhage, or deaths due to unknown cause.
  
  

Patient population This is an international, prospective cohort study of 10,000 adults undergoing non-cardiac, non-neurological surgery to determine the incidence of, risk factor for and impact of peri-operative stroke at 30 days after surgery.

Screening and enrollment:

Consecutive patients undergoing non-cardiac,non-neurosurgical surgeries during the assigned weeks will be recruited. Patients undergoing elective surgery will be assessed and recruited in preoperative clinics, days or weeks before the procedure. Patients requiring emergency time-critical surgery may not be able to provide informed consent and so their next-of-kin will be approached and provided with a plain language explanatory statement. If a next-of-kin is unavailable, we propose to enroll the patient in the study and obtain informed consent at a more appropriate time after surgery (i.e. deferred consent), usually within the first postoperative day. Efforts will be made to explain the features of the study to the patient. Deferred consent is considered appropriate because there is no intervention introduced in this study.

Procedure After obtaining written informed consent from eligible patients or their next-of-kin, research personnel will interview patients and review their charts to obtain information on patient characteristics that are potential predictors of peri-operative stroke.

Specific preoperative data will include: age, gender, a previous stroke (or transient ischemic attack), atrial fibrillation, peripheral vascular disease, congestive heart failure, diabetes mellitus, valvular heart disease, renal impairment, chronic obstructive pulmonary disease and tobacco use.

Monitoring, follow-up, and data collection: Treatment will be provided in accordance with local clinical practice. Details on surgical types (vascular, intra-peritoneal/intrathoracic, orthopedic or others) and anesthetic (general anesthesia and/or regional blocks) techniques will be sought. While in hospital, patients will be visited regularly. Each patient will be reviewed for neurologic deficit using the mNIHSS(modified National Institute of Health Stroke Scale):

1. preoperatively a baseline assessment and to determine if they have had a previous stroke;
2. before discharge from the post-anesthetic care unit (PACU) or recovery;
3. daily during the first two postoperative days;
4. upon hospital discharge If there is any change in the NIHSS (≥ 1 point decrease in the scale), the neurology service will need to be consulted. These patients generally will need to undergo a brain computed tomographic (CT) scan or MRI to determine the diagnosis. At 30 days after surgery, disability and functional assessments will be assessed by Barthel Index and modified Rankin Scale, and health status will be recorded using the EQ-5D scale.ED-5D(The EuroQol generic health index ) is a standardized and validated instrument for measuring health outcomes (including cardiac events). It is applicable to a wide range of health conditions and treatments. EQ-5D is recommended for use in cost-effectiveness analyses by Washington Panel on Cost Effectiveness in Health and Medicine.

Patients will be contacted by phone at 30 days after discharge to ascertain if they have experienced any adverse outcomes, and, if detected, further testing will be arranged. If patients indicate they have experienced an adverse event, their physicians, and hospitals will be contacted to acquire the appropriate documentation. Perioperative use of cardiac medication will also be recorded.