Do Arterial Catheters Reduce the Risk of Major Perioperative Complications

This study will be conducted at the Cleveland Clinic Main Campus with IRB approval and written consent from participating patients. The investigators will enroll consented ASA Physical Status 2-4 patients having inpatient non-cardiac surgery in whom a radial arterial catheter might or might not reasonably be used based on co-morbidity or type of surgery. However, it is most likely that the majority of patients will be ASA 3 patients. Currently (based on a recent data pull) approximately 44% of ASA 3 patients receive an arterial catheter for non-cardiac surgery. The investigators expect that this insertion rate will remain constant throughout the study.

Aside from randomized assignment to arterial catheter use, no other aspect of anesthetic or perioperative management will be controlled.

When attending anesthesiologists exclude otherwise qualifying patients from the study, the investigators will ask them to designate which factors influenced their decision. Potential reasons will include: 1) type of procedure; 2) co-morbidities; 3) expected hemodynamic instability or blood loss; 4) patient position; and, 5) need for blood sampling.

Demographic data to be obtained includes height (cm), weight (kg), age (yr.), gender, ASA physical status, and self-declared ethnicity. If available the investigators will collect social history (tobacco and alcohol use), medical history (pulmonary disease, cardiovascular disease, neurologic disease, drug usage (including but not limited to: statins, ß blockers, oral hypoglycemic agents and/or insulin), NSAIDs, diabetes (and whether insulin-dependent or not), and previous glucose-tolerance test results, preoperative hemoglobin and hematocrit, BUN and creatinine, electrolytes, preoperative EKG, and hemoglobin A1c (HbA1c).

Anesthetic data will include volatile anesthetic dose in MAC-hours, as well as total doses of propofol and other sedative hypnotics. Hemodynamic, respiratory parameters, BIS values (if available) and distal esophageal temperature will be recorded at 10 minute intervals intraoperatively. Blood loss will be estimated; urine output and fluid administration including allergenic blood will be recorded. Intraoperative use and total dose of vasoactive drugs as well as antibiotic administration will be recorded. The investigators will also record duration of anesthesia as well as time from induction of anesthesia to surgical incision. Similar data will be recorded for patients who potentially qualify but are excluded from randomization by the attending anesthesiologist.