Preoperative physiotherapy to prevent postoperative pulmonary complications after major abdominal surgery

Abdominal surgery is the most common major surgical procedure performed in developed countries. After surgery, postoperative pulmonary complications (PPCs) occur frequently and are a primary cause of morbidity, mortality, and prolonged hospital stay. To minimise PPCs, physiotherapy is ubiquitously provided in the postoperative phase in hospitals throughout developed countries. Physiotherapy clinical trials reporting the largest reductions in PPCs have predominately tested preoperative education and training of patients to perform their own breathing exercises after surgery. These trials were generally of low quality and therefore the results lack certainty. Currently, preoperative physiotherapy is rarely provided in Australian and New Zealand hospitals. A well-designed randomised controlled trial (RCT) investigating the benefit of preoperative physiotherapy to reduce PPC in a modern perioperative context was needed.

The aims of this thesis were to: consider the physiological basis for preoperative physiotherapy to minimise PPCs; to conduct a narrative and systematic review of research investigating PPC prevention with breathing exercises; and, to design and conduct an RCT, including quantitative, qualitative, and health economic outcomes, assessing the effectiveness of preoperative physiotherapy to minimise PPC after major abdominal surgery.

The Lung Infection Prevention Post Surgery Major Abdominal with Pre-Operative Physiotherapy (LIPPSMAck-POP) trial was a double-blinded, multicentre, RCT. In pre-admission clinics at three hospitals, 441 patients awaiting major abdominal surgery were randomised to receive an information booklet or an additional education and breathing exercise training session. Education focussed on PPC prevention via self-directed postoperative breathing exercises. A nested mixed-methods study investigated the impact and treatment fidelity of the intervention in 20 consecutive participants. Preventing pneumonia was very important to participants. Intervention participants found preoperative physiotherapy to be interesting and empowering with 94% of remembering the breathing exercises as taught.

Following surgery, PPC incidence was halved in the intervention group (adjusted hazard ratio 0.48, 95% confidence interval (CI) 0.35 to 0.75, p=0.001) with a number needed to treat of 7 (95% CI 5 to 14). Intervention participants had significantly reduced pneumonia rates, required fewer antibiotic prescriptions for respiratory infections, less purulent sputum, fewer positive sputum cultures, and were less likely to require oxygen therapy. An integrated health economic analysis found that preoperative physiotherapy had high probability of being cost-effective with an incremental net benefit to hospitals of $4,958 (95% CI $10 to $9,197) for each PPC prevented, given a willingness-to-pay of $45,000 for the service. Quality adjusted life year (QALY) gains were less certain. Improved cost-effectiveness and QALY gains were detected when experienced physiotherapists delivered the intervention. For each PPC prevented, preoperative physiotherapy was likely to cost hospitals less than the costs to treat a PPC.

This thesis analysed the evidence for the physiotherapy management of patients having abdominal surgery. A hypothesis for preoperative physiotherapy to minimise PPC after surgery was proposed. This hypothesis was supported with qualitative, primary, secondary, and health economic quantitative outcomes within a multicentre randomised controlled trial, and through a systematic review and meta-analysis.

These findings may not be generalisable to all settings and require testing in different surgical populations, cultures, and hospital settings. Effective PPC prophylaxis needs to be investigated for patients unable to attend pre-admission clinics, those having emergency abdominal surgery and in other high-risk populations.