Major Complications

Our specific aims are to investigate whether conservative (≤30%), intermediate (50%), or liberal (80%) inspired oxygen during and immediately after surgery: Aim 1: Reduces surgical site infections (SSIs or "wound infections") and other healthcare-associated infections (pneumonia and sepsis). Aim 2: Reduces a pooled composite of serious postoperative complications, leading to a faster and more complete recovery after surgery, and thus increases "days alive and at home up to 30 days after surgery" (DAH30). Primary hypothesis: Liberal (80%) oxygen concentration delivered with anesthesia in patients undergoing major surgery reduces the incidence of SSIs after surgery compared to conservative (≤30%) or intermediate (50%) oxygen concentration. Secondary hypothesis: Hyperoxia (50-80%) delivered with anesthesia in patients undergoing major surgery increases the incidence of pulmonary and other complications after surgery compared to conservative (≤30%) oxygen concentration, resulting in fewer Days At Home (DAH). PROMPT enrolls patients undergoing elective or semi-elective surgery.