Improvement in pre-operative risk assessment in adults undergoing noncardiac surgery by a process-oriented score

BACKGROUND: Pre-operative risk assessment is important to quantify the patient's risks of morbidity and mortality, but its quality differs. We created a process-oriented score (PRO-score) for risk evaluation of adults as a three-stage warning score checklist with concrete guidance. It contains the contents of current guidelines and the assessment of vital signs. OBJECTIVES: We investigated whether the PRO-score is suitable to detect 'red flag' warning signs not only in American Society of Anesthesiologists (ASA) physical status (PS) 3 or 4 patients but also in ASA-PS 1 or 2 patients. Resulting medical, therapeutic or structural consequences were recorded. DESIGN: Prospective single-centre study. SETTING: The study was performed in a German university hospital between November 2015 and December 2018. PATIENTS: We included 54 455 adult patients undergoing a pre-operative risk assessment for general or regional anaesthesia and elective noncardiac surgery. RESULTS: In all, 388 patients presented 'red flag' warning signs in the PRO-score during risk assessment; 85 (21.9%) were labelled ASA-PS 1 or 2, 244 (62.9%) ASA-PS 3 and 59 (15.2%) ASA-PS 4. Additional examinations were performed in 179 patients and technical tests in 175 patients (ASA-PS 1 or 2: 53 and 63 patients, respectively). After re-evaluation of the peri-operative risk in an interdisciplinary conference, surgery was cancelled in 44 patients (ASA-PS 1 and 2, 17 patients) or performed under local anaesthesia in 15 patients (ASA-PS 1 and 2, 2 patients). A downgrading to PRO-score 2 was reached in 168 patients after therapeutic interventions (ASA-PS 1 and 2, 54 patients). Undergoing surgery despite 'red flag' events resulted in major complications in 34 patients, and 16 patients died (ASA-PS 1 or 2: 7 and 3 patients, respectively). CONCLUSION: The PRO-score detected warning signs in 'healthy' ASA-PS 1 or 2 and in ASA-PS 3 or 4 patients. Furthermore, it influenced the management of these patients, and thus improved the process quality of risk assessment. The physical examination should include the assessment of vital signs.