Hogmanay Hypo

Edinburgh, Hogmanay, the Emergency Department: these are the nights we live for, but there can be an understandable anxiety when the big day approaches.

Despite, and probably because of, all the planning, this year, we remained relatively under control until the dawn was about to break on New Year’s Day.  At this point, the massed reinforcements of doctors, nurses, domestics, radiographers, receptionists, therapists and managers all descended to sweep up and treat the remaining patients who had been waiting longer than we and they would have liked, and we had cleared the backlog by the middle of the morning.

Contrary to popular belief, it is the 1st January that is usually our most challenging day, and the aftermaths of committed revelry continue to turn up at our doors, along with all the usual medical and traumatic emergencies, for the next 24 hours.

One such sufferer is “Unknown Unknown” (as our system is required to name them until their identity can be confirmed).  Ms Unknown is a young looking lass, who can’t weigh more than about 9 stone, and is not dressed for winter.  She is barely dressed at all.  She has been found at a bus stop, and some passers-by have tried to rouse her, and have called an ambulance out of concern.  She is one of a few every year that, in a haze of alcoholic bravado and misadventure, become separated from their herd on this famous night out, and end up lost, abandoned, confused, and cold.

It turns out that U.U. is very cold.  On picking her up at the bus stop, the ambulance crew were unable to record her temperature using a standard ear probe.  She is unresponsive, her heart rate is irregular and slow, her pulse barely palpable, and her blood sugar level is low.

She is brought into the resuscitation room in the Emergency Department, where she is moved over to our trolley super-carefully – any sudden movements in very cold patients can occasionally cause their hearts to go into cardiac arrest. Because of her low body temperature, we have to use a rectal temperature probe to measure her core temperature.  This measures her temperature as 29.6 degrees Celsius.  At this level, most of her body systems will be dysfunctional. 

She is so cold that she will have lost the ability to shiver and create heat herself.  Her heart is beating slowly and in an abnormal irregular rhythm.  The heart tracing shows this and bizarre extra waves due to the disturbance in her cardiac circuitry.  We will definitely have to tread carefully as we begin to manage her condition.

All the veins in her arms and legs have shrunk away in an attempt to divert blood away from her skin to keep her warm, which makes finding a vein to replace fluid and sugar nearly impossible.  We use an ultrasound machine to locate a vein and manage to insert an intravenous drip.  She is dehydrated due to the exertions of her night out, plus the various changes in the way her body manages fluids when hypothermic, meaning we will have to replace relatively large volumes of intravenous fluid.  This has to be warmed to body temperature first, and well balanced to avoid any further damage to her fluid balance.  We add in some sugar replacement to provide some fuel for the fires that will hopefully start to warm her up.

At this low temperature, her lungs will not be inflating as deeply as they should, and fluid and debris will collect as she is unable to cough properly.  Her kidneys will be unable to preserve the right amount of water and salts, causing her to continue losing fluid, and running the risk of kidney damage.  Her hormonal systems will all be off kilter, and she will also be more likely to form clots in her circulation during this very cold stage.

Once we have got intravenous access, and placed a catheter in her bladder, we wrap her in our external warming device – the Bair Hugger.  This is an air mattress with holes in it that attaches to a hot air blower, and which we then wrap over her and cover in blankets.  Now the process of gradual re-warming can begin, with a combination of warm intravenous fluid, warm external air, and warm fluid irrigating her bladder.  If required, we can irrigate various other body compartments with warm fluids, or even use cardiac bypass (as in open-heart surgery) to re-warm patients who are incredibly unwell or in cardiac arrest.

Fortunately, this young lady is relatively resilient, and can withstand the rigours of being extremely cold.  We aim to re-warm no quicker than 1 degree per hour, so it will be a good 7 hours at least before she is back up to normal temperature.  As the warming process continues in the Emergency Department and in our Intensive Care Unit, she gradually regains consciousness, and her body systems start to recover.

Whilst we learn her name, we are no clearer as to the circumstances of her separation and her ending up in a bus stop.  At least she is able to go home after another few days in hospital.  Many of our more elderly patients would not be so lucky.