New circadian clock findings may transform post-anaesthesia recovery
New insights into the effects of anaesthetic drugs on the human circadian clock may lead to patients recovering quicker and being sent home sooner.
Associate Professor Guy Warman is presenting his findings at the Australian and New Zealand College of Anaesthetists (ANZCA) Annual Scientific Meeting (ASM), being held in Auckland.
The circadian clock regulates the body’s sleep-wake cycles, metabolism, and response to light-dark cues.
Associate Professor Warman, from the University of Auckland, says the body’s circadian clock has an important role in maintaining good general health.
“One of the things about circadian clocks is that profound rhythms, really strong daily rhythms, are very important for our health and wellbeing.
“Our metabolism and our immune function are all profoundly affected by our circadian clocks.”
However, he says these rhythms can be impacted by anaesthetic drugs.
“Anaesthetic drugs can disrupt our circadian rhythms, so if we can work out ways of reducing that anaesthesia-induced circadian clock disruption, we might be able to speed up patient recovery and send people home more quickly.”
Associate Professor Warman and his colleagues have investigated ways to lessen this disruption, with light exposure being considered as one way to speed up post-operative recovery.
He says measures such as strengthening the intensity of light-dark exposure and day-night cycles in the hospital can improve post-operative patient recovery.
“There are a range of different studies from psychiatric inpatients to surgical patients showing that those patients in rooms with strong light-dark cycles, particularly morning light, recover more quickly than those who don’t have those strong light-dark cycles.
“Even small advances in the area of trying to support patient circadian rhythms could have big effects on wellbeing, underlying immune function, and time to discharge.”
Alongside this, Associate Professor Warman says the time of day a patient receives an anaesthetic may influence how strongly it works, how long it works for, and have a significant impact on patient recovery.
“Things like local anaesthetics will last a lot longer when taken at three o’clock in the afternoon than at other times of the day.
“There’s a lot of research coming out internationally suggesting that these aren’t just trivial effects…they’re actually quite profound, and by understanding them you might be able to understand how to use levels of drugs that keep people at the right level of anaesthesia, the right level of analgesia, and yet don’t last too long post-operatively to prolong recovery.
“I think we’re almost getting to the point where we can start to advise about how to change clinical practice, I don’t think we’re at the point where we can say ‘you need to administer this amount of drug for that’, but I do think we’re at a point where we understand that a lot of the variability that anaesthetists will see using drugs, might be due to time of day.”
The ANZCA ASM is being held at the New Zealand International Convention Centre in Auckland until Tuesday 5 May. More than 1800 delegates are attending the meeting, which has attracted anaesthetists and specialist pain medicine physicians from Australia, New Zealand the US and the UK to discuss the latest advances in anaesthesia, pain medicine and perioperative care.
