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Statistics take the helm in cycles

by
01 August 2016, at 1:00am

Dr David Williams keeps an eye on the safety record of Cambridge’s residents and recalls his own rather lucky escape some years ago.

CAMBRIDGE CAN BOAST 92 Nobel prize winners. It’s not unheard of to bump into one of them in the street or even waiting at the supermarket checkout.

And if it’s not one of that highly elevated elite, then you may well be standing next to an eminent expert in his or her eld. Imagine all those hyper-intelligent neurons!

Yet, in a town where the key method of transport is the pushbike, it seems ridiculous to me that so few of these mega-brains are protected by a helmet.

I must admit that I drive into the vet school each morning from my home in a village near Cambridge. I spend most of the day motoring around to veterinary practices and providing them with an ambulatory ophthalmic referral service – a diamond burr for a chronic corneal ulcer here, help with a complicated eyelid reconstruction there. And on my way into town each morning, I keep a little tally of the number of people on bikes wearing cycle helmets. 

Things have improved over the past few years. Each year of the past three there has been an increase in the number of riders wearing helmets, but still a good deal fewer than half of the population are wearing appropriate protection. You may wonder why I have chosen that subject for this month’s perambulation. It was 25 years ago, on 12th August, the glorious 12th, that I was cycling to work, in a bit of a rush, and forgot to wear my helmet. I was almost half way through my PhD at the Royal Veterinary College in Camden, north London, but lived in Clapham, south London, just by Clapham Common.

Catastrophic crossing

A tiny lane crosses the Common, one that the cycle lane itself crosses and I must have misjudged the speed of the oncoming car. It should have been 30mph or lower, but the police calculations from the skid marks showed it must have been doing well over 10 miles more than that.

By now you can imagine the scene. Hit by the car as I crossed the road on my bike, I bullseyed the windscreen and then bounced off onto the iron railings by the side of the road. An interesting set of pathologies set in motion.

My skull stopped instantaneously as it hit the windscreen but my brain kept going, tearing neurons to give what is known as diffuse axonal injury. It also damaged the blood vessels giving a number of intracranial bleeds, as you can see in the CT scan here with the white circle showing a big haemorrhage in my internal capsule.

Those would have been a bigger problem, but hitting the railings ruptured one of my mesenteric arteries, so I started bleeding out internally, dropping my blood pressure and reducing the impact of the intracranial bleeds.

The good Samaritan

The only trouble was that the blood loss would soon have killed me but for a gentleman looking down out of his bedroom window. He saw the accident and immediately rang 999. It was rush hour so a land ambulance didn’t stand a chance of getting there in time, but being injured on the Common gave a perfect landing spot for the helicopter ambulance.

Forget the “golden hour” post- trauma, HEMS (the helicopter emergency services) was with me in six minutes and I was intubated, anaesthetised and on 100% oxygen. A quick flight to the Royal London Hospital and some emergency surgery and hey presto – I’m here today!

Well I have to say there were months of recovery first in hospital and then at home before getting back to the RVC and a lot of love and care from Jennie who at the time was my fiancée. And I have a feeling there was someone else looking down on me that day as well as the man in his bedroom!

Incidentally you may wonder how I know about him. We reconstructed the accident for BBC 999 Lifesavers a few years later and this man, I never found out his name, came over and asked me if I was the cyclist. Knowing I had survived gave him a sense of closure I think, which was good.

Now HEMS had quite a trial in those days trying to convince people that it provided a worthwhile service. That seems crazy now with Trauma Doctors and 24 Hours in A&E on our screens all the time, but then there were a fair number of people who doubted how many lives really were saved.

As far as I can see it’s not just lives saved but lives restored – I could have lived but been severely brain damaged but for that rapid intervention. And there are still people who doubt whether helmets are as effective as others say they are.

The advocates and opponents of helmet wear seem to shout at equal volume, though a Cochrane database meta-analysis concluded that “Helmets provide a 63 to 88% reduction in the risk of head, brain and severe brain injury for all ages of bicyclists.” That’s enough for me.

Murphy’s Law

Well of course I did have a helmet. I wore it every day on my cycle across London. Every day that is until the one day I needed it! It’s just that lying by my bedside table it wasn’t particularly helpful in those few traumatic seconds.

So I don’t know if you have a cycle helmet. If you don’t, buy one today. And if you do, please make sure you wear it every time you go out on your bike.

Just today I spoke to a doctor in Cambridge who told me that she knew she should be wearing a helmet, but that it just so messed up her hair every day she wore it. I told her that her hair would look an awful lot messier with bits of skull, blood and brain tangled up in it! And on that happy note I’ll wish you a sunny rest of the summer!