Earlier this year we interviewed Dr Sarah Hollis and learnt about her work on Non Freezing Cold Injury (NFCI). Following this, Sarah has published a case series based upon more than a hundred NFCI patients referred to her clinic. We asked Dr Lewis Mallon, an ENT SHO and someone unfamiliar with NFCI, to take a look at the study and tell us what he thought...
"Earlier this year, two friends and I had the opportunity to climb a 6100m peak in the Cordillera Real in Bolivia. Bolivia is renowned in South America for cheap prices and this was reflected in the cost of renting gear. We needed a fair amount of kit including sleeping equipment, ice picks and crampons, and managed to hire them at a fraction of the price one would expect to pay in a developed country. So, despite our lack of experience, we couldn’t let the chance of climbing our first ‘6000er’ slip by!
The Cordillera Real mountain range in Bolivia
Fast forward four days and we are at the summit, the oxygen levels are low and breathing is noticeably harder. Needless to say, it is COLD! In fact, it had been very cold the whole time. What I failed to foresee prior to setting out was that with low prices comes low quality. Our boots were not as waterproof as promised and we spend each night shivering through to morning in our ‘genuine fake’ North Face sleeping bags. Essentially the cold was inescapable. I guess we were being audacious to expect anything else. The sense of triumph at the summit was marred slightly by the lack of sensation in my extremities. All I wanted to do was descend quickly, have a warm meal and get some feeling back into my toes, which were in agony at this point!
Fast forward four weeks and the sensation in my toes still had not returned. I couldn’t really make sense of what had occurred, but I left it, not giving it much thought until I read Dr Hollis' study months later.
SO THAT WAS WHAT IT WAS!
Non Freezing Cold Injury (NCFI) is characterised by a history of significant cold exposure causing acute sensory symptoms followed by a painful rewarming period. Then there is an element of residual sensory symptoms – such as burning, tingling, numbness etc. The extent ranges from symptoms that recover in a few days to cases with persistent sensory deficits and neuropathic pain. Historically (for instance in the trenches in World War 1) cases progressed as far as gangrene and necrosis, but this classical presentation is now uncommon.
A case of Non Freezing Cold Injury (NFCI) sustained at high altitude. Whilst the majority of NFCI victims recover completely, some go on to develop persistent sensory loss, neuropathic pain and hypersensitivity to cold (Image: Mehmet Karatay)
Dr Hollis has been running a specialist NFCI clinic for 4 years and has recently given an interview to Surviving the Death Zone. You should check it out if you haven’t done so already!
NFCI was found to be more commoner amongst those in the initial stage of their military training which seems logical as they’re more likely to be exposed to cold and wet conditions due to their field tasks, combined with a relative inexperience of coping compared to their senior colleagues. But the most specific risk factors were the feeling of subjective coldness and being assigned to static duties. Other pertinent associations were having wet clothing and being immersed in water.
An important finding was the lack of knowledge and appreciation of NFCI within the military. But then I hadn’t heard of it and I’m a doctor! The study hopes to use its findings to raise awareness of NFCI and educate those who are most at risk.
In summary, I learnt from Dr Hollis' study the signs and symptoms of NFCI and the complications that can occur. Practically, I now know that feeling cold and being stationary for long periods of time are risk factors for NFCI. These are things to look out for whenever you’re trekking in the snow, open water swimming in winter or whatever nonsense you choose to partake in! Above all, listen to your body and keep warm!
Oh, and the feeling came back to my toes. Eventually!"
Thanks Lewis! The abstract of Dr Hollis' study can be found here.
Email us if you'd like a copy of the study.