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Effectiveness and cost-effectiveness of inspiratory muscle training for reducing postoperative pulmonary complications: a sham-controlled randomised controlled trial

Chief Investigator



Funding Stream

Grant Ref


Dr Maria Pufulete

University Hospitals Bristol NHS Foundation Trust and University of Bristol


(42 months)

NIHR Health Technology Assessment (HTA)




After major operations, some patients develop complications of the lungs, including pneumonia. These complications can be serious and may result in long stays in hospital, admission to intensive care and even death. They also prolong recovery and reduce patients' quality of life. Lung complications after surgery have a longer term effect, increasing the risk of dying for up to ten years. Poor health due to lung complications also increases healthcare costs. Lung complications are common, affecting on average one in ten patients, with the risk for a particular individual depending current health and the type of surgery. Consequently, trying to prevent lung complications is important for patients and the NHS.

Inspiratory muscle training is a package of breathing exercises to improve the strength and endurance of the muscles in the chest which control breathing. The exercises involve breathing in and out through an inexpensive, hand held device which makes breathing difficult. Training is completely safe. It takes approximately 15 minutes twice a day and can be performed at home when sitting down. Recent studies have suggested that training for as little as 2 weeks before an operation might halve the risk of lung complications. Unfortunately, the benefits of breathing training remain uncertain because the previous studies recruited too few patients and many were not done well.

We propose a large study to investigate whether breathing training reduces lung complications in patients at high-risk of lung complications after major surgery. We will invite adult patients having operations in the chest or abdomen under general anaesthesia who have a high risk of lung complications to take part. We will randomly assign participants to one of three different types of treatment in the period leading up to the operation.

The clinical team looking after patients at the time of surgery will not know which group they are in. The effect of the training will be assessed immediately before the operation by testing the strength of the respiratory muscles. We will also monitor how much training patients are able to complete. Our main aim is to compare the risk of lung complications in the three groups, to establish if breathing training is beneficial to patients. We will also compare the time patients spend in hospital, their quality of life after their operation and survival. The costs of the treatment and any cost savings caused by staying less time in hospital will also be investigated.

Further information