Complications and mortality in older surgical patients in Australia and New Zealand (the REASON study): a multicentre, prospective, observational study

We conducted a prospective study of non-cardiac surgical patients aged 70 years or more in 23 hospitals in Australia and New Zealand. We studied 4158 consecutive patients of whom 2845 (68 ) had pre-existing comorbidities. By day 30, 216 (5 ) patients had died, and 835 (20 ) suffered complications; 390 (9.4 ) patients were admitted to the Intensive Care Unit. Pre-operative factors associated with mortality included: increasing age (80a??89 years: OR 2.1 (95 CI 1.6a??2.8), p <0.001; 90+ years: OR 4.0 (95 CI 2.6a??6.2), p <0.001); worsening ASA physical status (ASA 3: OR 3.1 (95 CI 1.8a??5.5), p <0.001; ASA 4: OR 12.4 (95 CI 6.9a??22.2), p <0.001); a pre-operative plasma albumin <30 g.la??1 (OR: 2.5 (95 CI 1.8a??3.5), p <0.001); and non-scheduled surgery (OR 1.8 (95 CI 1.3a??2.5), p <0.001). Complications associated with mortality included: acute renal impairment (OR 3.3 (95 CI 2.1a??5.0), p <0.001); unplanned Intensive Care Unit admission (OR 3.1 (95 CI 1.9a??4.9), p <0.001); and systemic inflammation (OR 2.5 (95 CI 1.7a??3.7), p <0.001). Patient factors often had a stronger association with mortality than the type of surgery. Strategies are needed to reduce complications and mortality in older surgical patients.