AAGBI/Anaesthesia Research Grant

Qualitative Methods in Understanding Patient Safety in Intensive Care

Dr Timothy Dawes

More than 90,000 patients in US hospitals die each year as a result of errors by health-­â€workers. Errors are common in intensive care with 45.8% of admissions associated with an adverse event, and an average of 1.7 errors per patient, per day. This is particularly concerning, since patients on intensive care units (ICUs) have complex medical problems with finely balanced physiology where sub-optimal treatment is likely to be poorly tolerated.

Traditional approaches to patient safety contend that safety is achieved by minimising error. Investigations are triggered by the occurrence of an adverse event (AE), rooted in the idea that AEs demonstrate single, causative errors in the system which should be identified and changed. Critics suggest that this "reactive" approach is flawed by the assumption that AEs are always due to error, that AEs are characterised by isolated errors, and that the best lessons for improvement occur from the most serious AEs. Systems approaches suggest that AEs are the result of a chain of contributory factors divided into "active" and "latent" failures. This approach has gained credence in other safety‐critical environments, such as air‐travel and industry. Interest in safety culture has steadily increased and understanding the development stage of a healthcare environment is a key stage in improving safety culture.

Surveys and checklists have been widely used for this purpose; though consistently suffer from poor return‐rates, an inability to explore pertinent threads and a lack of contextual information. Qualitative methods may offer a more flexible method of understanding the causes of error.

This study aims to apply a qualitative approach to identifying and describing the barriers to safe practice in adult intensive care. We hypothesize that qualitative methods can access both a broader variety of underlying error causes and a significant number of unreported errors. As part of this investigation we hypothesize that qualitative methods are particularly suited to identifying latent failures.

Evaluation of the microstructure and functional changes in the lung during recovery after major abdominal surgery, using functional hyperpolarized helium and xenon magnetic resonance imaging

Professor Gary Mills

Lung related problems are probably the most common major complications in the time after a surgical operation. These affect thousands of patients every year, many of whom are then admitted for treatment to intensive care. These lung problems contribute considerably to the 4 in 100 deaths that occur within 30 days of major surgery. There are several contributory factors, including the effects of the surgery, which will cause inflammation in the body and may also cause compression of the lungs with instruments to hold open the wound during the operation. Also during anaesthesia the majority of major surgery cases will need to be put on a ventilator. This will perform the work of breathing for the patient, as they will not be able to breathe effectively for themselves, because of the needs of the surgery.

Unfortunately ventilators blow air into the lungs rather than drawing air in during inspiration, as is the case in normal breathing. This can over-expand or apply too much pressure to the lungs and however careful the anaesthetist is with the ventilator settings, there will be areas of lung collapse due to the weight of the lungs, heart and other structures compressing the air spaces. There will also be areas in the upper part of the lungs that will be over-expanded. In addition contaminated material from the mouth may squeeze past the cuff on the tube connecting the patient to the ventilator, which can cause more damage.

Research has begun to look at how we might best reduce these complications by setting the ventilator to produce low pressures and low breath sizes. Respiratory complications may occur immediately after surgery and in the coming days and weeks. Patients may be breathless on exercise and slow to recover. Therefore we aim to use specialised magnetic resonance imaging (MRI) (5) of the lung before, a week after and later following surgery to see how the lungs recover in much more detail than has been possible before. This MR imaging will show how the lungs change after the combination of surgery, mechanical ventilation and anaesthesia, as well as how well they recover after time. In particular novel features they can show include how much oxygen is being taken up in different areas of the lungs, how big the air sacks and air passages become (some will collapse and some will become overinflated), how well the oxygen can pass through the wall between the blood vessels and the lungs, and the distribution of gas within the lungs (identifying ventilated and un-ventilated regions). Once we better understand how the lungs behave in the weeks after surgery, compared to the preoperative period, we can then address how we can improve recovery. We will then also understand how better to targets our studies in patients in the immediate postoperative period, when these magnetic resonance techniques would be more challenging.

Coronary Anatomy & Dynamic Exercise Testing (CADET)

Dr Gary Minto

Preoperative assessment before major surgery aims to identify those patients who are at high risk of complications and death while recovering from surgery so that we can focus resources on them. Categorisation of risk is based mostly on patients` heart function. However clearcut "heart attacks" after surgery are relatively rare.

A theory is that heart disease has a knock on effect on other organs, leading to complications because the heart is unable to deliver oxygen (in the blood stream) that is needed for healing in other parts of the body.

Patients with coronary artery disease - narrowings or clots in the blood vessels through which the heart supplies itself with oxygen so it can pump - may in addition be at risk for heart attacks if clots block up those vessels.

If we measure high sensitivity Troponin (a blood test which parallels the degree of heart muscle damage) after surgery, this will be raised in up to 50 % of "high risk" patients, and these patients are much more likely to get complications or die than those without a raised troponin.

This theory puts the heart at the centre of postoperative complications, but we do not know whether all the patients at risk have abnormalities of heart function or coronary artery disease that could be identified before surgery.

This study uses two preoperative tests to explore the heart structure (CT Coronary Angiography, CTCA ) and function (Cardiopulmonary Exercise Testing, CPET ) before surgery.

CPET is already part of routine preoperative assessment, a bicycle exercise test that gauges objectively how well a patient is able to pump increased blood supply to exercising muscle. Patients who do badly at this are more likely to suffer complications after major operations.

CTCA has previously not been routinely done since it involves a high radiation CT scan of the heart. New technology allows us to perform CTCA with a very much lower radiation dose - and since many patients being assessed for surgery already have CT scans of their chests before an operation ( for example to check for cancer spread) , we can now perform CTCA to look in depth at the coronary arteries.

We propose to do both tests in the same patients to see whether either of them provides important information that the other test does not.

For a substudy, we also want to gather data about whether using both tests together helps predict which patients will get complications after surgery; which will have a raised troponin blood level after surgery, and which patients are likely to either have died or still have poor functional capacity a year after the operation. To fully explore these questions would require a much larger study than this one is, but the pilot data will allow us to work out how large it needs to be, and generate some ideas about whether there are particular groups of patients at risk who might be identifiable by CTCA and CPET before surgery.

A pilot observational study to evaluate the feasibility and effectiveness of an Enhanced Recovery Pathway (ERP) in complex thoracoabdominal aortic aneurysm repair

Dr Judith Partridge

An aneurysm is ballooning of a blood vessel. Three quarters of aneurysms which occur in the major blood vessel, the aorta, occur in the abdominal aorta and the rest in the chest. The main problem with these aneurysms is that they are at risk of rupture and left untreated this will be fatal in four out of five people. As surgical techniques have progressed many more complicated aortic aneurysms can now be treated than before.
Whilst this represents marked progress there is still room for improvement in standardising the processes of care that patients receive both within a single hospital site but also between hospitals. These processes include things that happen before the operation (such as how patients are assessed prior to surgery, which tests are carried out, what information is provided), things that happen during the operation (how people are monitored, which anaesthetics are used, where they recover from the anaesthetic) and how they are managed after surgery (which kind of ward do they go to, when can they get up and walk after surgery, should they receive blood transfusions etc).

In other surgical specialities so called 'enhanced recovery programmes' (ERP) have aimed to bring many components such as these into a standard pathway of care that all patients follow. These programmes are thought to minimise the 'stress' of surgery for patients and have shown success in reducing complications after surgery and reducing the length of hospital stay.

This project proposes to develop and implement a similar enhanced recovery programme for patients undergoing this newer form of complex aneurysm repair. It is a joint programme between anaesthetists, surgeons and physicians to ensure that patients are well managed throughout the whole pathway.

Before surgery patients will be assessed and optimised by a team of doctors, nurses, therapists and social workers to make sure that they are as prepared as possible for surgery. Patients will be discussed in a meeting between medicine, anaesthetics and surgery and the risks of the operation will be fully discussed with patients (and their families where appropriate) to allow shared decision making. The anaesthetists will work to several set goals of treatment (for example blood pressure, oxygen levels) and this approach will be continued after the surgery when the patient is back on the ward. All patients will be helped by therapists to get up and walk the day after surgery to help prevent complications and keep them well. We will measure how many of the components of the programme are achieved and we will also describe outcomes including medical complications, length of stay and quality of life. Furthermore we would like to explore the patient experience of having an operation using this new pathway of care. We will ask how prepared they felt for surgery, how involved they were in the decision making process and how much they understood about what would happen in hospital and when they were discharged from hospital.