BJA/RCoA Project Grants

Background
Chronic pain is a burden to both patients and the NHS. Many patients live with severe pain which is resistant to pain relief medication. We have recently found that over 40% of patients attending a pain management clinic in Northeast Scotland rated their pain at levels of 7 or more out of 10, indicating severe pain. Our earlier work showed that higher pain scores were linked to more disturbed sleep and poorer sleep quality.

Melatonin is produced in the body mainly by the pineal gland, which sits just below the brain, and controls sleeping patterns. Melatonin can also be manufactured chemically in the laboratory and given as a medication and is very safe. In people with sleeping problems melatonin has been shown to be effective at improving sleep. Melatonin has been shown to be safely given to patients with various other conditions for months at a time with no ill effects. It has been shown that as well as regulating sleep, melatonin may also act like a pain-killer (analgesic) in some pain conditions.

Aim
In this study we propose to investigate whether giving melatonin to patients with severe chronic pain will improve both patients' sleep and their pain.

Study design
Participants will be recruited from the chronic pain clinic at Aberdeen Health Village. We will include those who report a pain score of 7 or more, indicating severe pain. Participants will be randomised to take either melatonin tablets or a placebo (dummy drug) just before bedtime, every night for 6 weeks, followed by a week taking nothing, then 6 weeks taking melatonin if they got placebo first, or vice versa. We will assess whether melatonin improves their sleep and has any effect on pain scores. We will also measure blood levels of melatonin at intervals and use a computer based task to assess if melatonin is causing sleepiness during the day. Participants will also wear an activity watch and will input real-time pain and fatigue scores into it. At the end of the trial we will ask participants to complete a short survey to gather feedback about the trial. This will contribute to improvements in future trial design and conduct as seen from participants' viewpoints.

Outcome
This study will tell us if melatonin is able to improve sleep and pain in patients with chronic pain and may provide a useful additional treatment option for this group of patients.

Ultrasound guided regional anaesthesia is an intervention whereby a needle is inserted through skin under ultrasound guidance and rests as close to but not touching a target nerve. Local anaesthetic renders arms and legs completely numb for surgery. This means that patients who are elderly, obese, diabetic or ill can be operated on without resort to general anaesthesia, get better more quickly, and even go home after their operation.

However, the public are unaware that anaesthetists first practice technical needling skills on patients. This exposes patients to: repeated insertion attempts, severe pain and electrical shocks down the arm or leg, or even local anaesthetic induced convulsions or cardiac arrest. Practical training courses are available but trainees, in the main, attend them after attempting nerve blocks on patients. Teaching is not measured or evidence based. For an educational course to have an impact, it must not just improve skills on the day, but maintain skills such that performance on a patient 2 to 3 months later is better than it otherwise would have been, had no training taken place. Twelve controlled studies have investigated the role of nerve block simulation training with one showing specific benefit when skills were translated to patients.

In Dundee, we have the resource and experience to remedy this problem. We have the best simulator of regional anaesthesia - the soft embalmed Thiel cadaver that looks like and feels like a patient because it is soaked in vats of acid and salt for 6 months. Nerves and muscle are seen readily on ultrasound. Injection of fluid around nerves behaves like that seen in patients and disperses as quick because cadaver tissue is elastic. Hundreds of injections can be performed without damage.

We have also developed objective measures of performance that reflect the quality and outcome of nerve block. Using a repeated questionnaire method, 16 UK experts identified 17 steps key to success and 21 errors to be avoided. We also conducted the largest, most detailed study of eye tracking in anaesthesia. Eye tracking gives an idea of what people see and how they make decisions. Special glasses identify the movement of the pupil during the nerve block process, tracking what the trainee focuses on and when they glance away from the site of interest. Our results offer very detailed analysis of performance that differentiate between all levels of performance. We want to conduct three studies that test the effect of simulator training on clinical performance and patient outcome. We want to ensure our step and error metrics are reliable. Then we want to see if extra training on our soft embalmed cadaver is better than standard course training alone. We will then see if applying a well-established and proven educational method called mastery learning to cadaver simulator training improves performance when anaesthetists perform nerve blocks on patients.