Non-Invasive Positive airway Pressure thErapy to Reduce Postoperative Lung complications following Upper abdominal Surgery (NIPPER PLUS): protocol for a single-centre, pilot, randomised controlled trial.

INTRODUCTION: Postoperative pulmonary complications (PPCs) are a common serious complication following upper abdominal surgery leading to significant consequences including increased mortality, hospital costs and prolonged hospitalisation. The primary objective of this study is to detect whether there is a possible signal towards PPC reduction with the use of additional intermittent non-invasive ventilation (NIV) compared with continuous high-flow nasal oxygen therapy alone following high-risk elective upper abdominal surgery. Secondary objectives are to measure feasibility of: (1) trial conduct and design and (2) physiotherapy-led NIV and a high-flow nasal oxygen therapy protocol, safety of NIV and to provide preliminary costs of care information of NIV and high-flow nasal oxygen therapy.

METHODS AND ANALYSIS: This is a single-centre, parallel group, assessor blinded, pilot, randomised trial, with 130 high-risk upper abdominal surgery patients randomly assigned via concealed allocation to either (1) usual care of continuous high-flow nasal oxygen therapy for 48 hours following extubation or (2) usual care plus five additional 30 min physiotherapy-led NIV sessions within the first two postoperative days. Both groups receive standardised preoperative physiotherapy and postoperative early ambulation. No additional respiratory physiotherapy is provided to either group. Outcome measures will assess incidence of PPC within the first 14 postoperative days, recruitment ability, physiotherapy-led NIV and high-flow nasal oxygen therapy protocol adherence, adverse events relating to NIV delivery and costs of providing a physiotherapy-led NIV and a high-flow nasal oxygen therapy service following upper abdominal surgery.

ETHICS AND DISSEMINATION: Ethics approval has been obtained from the relevant institution and results will be published to inform future multicentre trials.

TRIAL REGISTRATION NUMBER: ACTRN12617000269336; Pre-results.