Intraoperative adverse events and related postoperative complications in spine surgery : Implications for enhancing patient safety founded on evidence-based protocols

Prospective observational study. To assess the incidence and clinical consequence of intraoperative adverse events from a wide variety of spinal surgical procedures. In this study, adverse events were defined as any unexpected or undesirable event(s) occurring as a result of spinal surgery. A complication was defined as a disease or disorder, which, as a consequence of a surgical procedure, will negatively affect the outcome of the patient. We hypothesized that most adverse events would not result in complications that would be normally flagged through traditional practice audit approaches. By defining the incidence and types of adverse events seen in a spine surgical practice, we hope to develop preventative approaches to enhance patient safety. All postoperative clinical sequelae (i.e., complications) were prospectively identified, classified as to type, and graded (0 [none] to IV [death]) in 700 consecutive patients who underwent spine surgery (excluding > 300-day surgery microdiscectomies) at a university center from January 2002 to June 2003. To confirm data accuracy and assess the clinical sequelae of any adverse events, the medical records of these 700 patients were reviewed. The overall incidence of intraoperative adverse events was 14% (98/700). A total of 23 adverse events led to postoperative clinical sequelae for an overall intraoperative complication incidence of 3.2% (23/700). Specific adverse events included dural tears (n = 58), spinal instrumentation-related events (n = 12), blood loss exceeding 5000 mL (n = 10), anesthesia/medical (n = 4), suspected or actual vertebral artery injury (n = 3), approach-related events (n = 3), esophageal/pharyngeal injury (n = 2), and miscellaneous (n = 6). Adverse events can frequently occur (14%) during spinal surgery, however, the majority (76.5%) are not associated with complications. Improved patient safety can only be maximized by independent practice audit and the development of prospective methods to record adverse event data so that enhanced, evidence-based, clinical protocols can be developed.