Intended for healthcare professionals


Snow in UK results in cancellation of surgery and outpatient clinics

BMJ 2010; 340 doi: (Published 12 January 2010) Cite this as: BMJ 2010;340:c194

Frostbite cases on the increase?

Dear Editor

The debates over the effects of the current freezing weather and its
associated impact upon healthcare (Ref: snow in the UK results in
cancellation of surgery and out patient clinic) often seem to focus on the
adverse effects upon service provision and financial penalties that may be
incurred by the health service. However, the effects of a sustained period
of severe cold weather also bring challenging health care problems to
frontline doctors in terms of treating unfamiliar conditions that are not
normally seen in the UK.

Frostbite is usually thought of as a problem faced only by
mountaineers or those on Arctic expeditions but over the past few days we
have been seeing a number of people with frostbite injuries on our burns
unit. This is somewhat unusual, even for a unit such as ourselves with
many staff struggling to remember the last case of frostbite they treated.
Similarly referring units have not experienced these injuries and are
often unsure as to how to manage these patients prior to transfer.

Frostbite generally affects the extremities and is secondary to a
freezing cold injury i.e. that occurring at temperatures below 0oC. The
cold produces vasospasm and venous stasis which propagates further heat
loss and leads to the formation of ice crystals within the intra and
extracellular spaces. These changes result in tissue ischaemia the degree
of which is proportional to the temperature and duration of contact, but
may be significant.

The history of injury is often suggestive of frostbite. Recent case
examples being a young child who had been playing all day in the snow with
wet socks and a man who had walked some distance barefoot in the snow.
Frostbite cases typically present to medical attention following a period
of initial anaesthesia and blistering which is followed by intense pain on
re-warming. Frostbite is a spectrum of injury and appearances may range
from a small area of blanching to large areas of blistering and waxy,
yellow skin. Following re-warming the area may even take on a cyanotic

Correct management of acute frostbite is critical and all cases
should be discussed with a specialist unit. If there is a genuine freezing
injury the clinician must be look for signs of associated pathologies
which are frequently seen in patients with frostbite, such as head injury
and hypothermia and treat these accordingly. However assuming an isolated
frostbite injury the affected area should be immersed in a warm water bath
(ideally a ‘whirlpool’ foot spa-type device) containing an antibacterial
solution, such as chlorhexidine at a temperature between 38-42oC for a
period of at least 30 minutes. This process should be repeated twice a day
during the initial period of injury until the open areas have dried up and
are showing signs of healing. After bathing the area can be gently dried,
leaving any blisters intact. Soft dressings should be applied loosely,
with no additional pressure placed on the injured tissues and the affected
region must be fully immobilised and elevated. The patient must remain
strictly non-weight bearing on frostbitten areas as the tissues will be
critically ischaemic, thus any pressure on these areas will further
compromise the tissue oxygenation and propagate additional ischaemic
changes. Similarly patients must be advised not to smoke in order to
minimise tissue loss as the smoking-related vasospasm significantly
affects critically ischaemic tissues.

The thawing process may be very painful and patients will often have
substantial analgesic requirements during this period. If there appears to
be a significant area of tissue necrosis then broad spectrum antibiotics
should be commenced. These patients should not generally be considered for
early surgery as the severely affected necrotic areas will demark with
time and areas that initially may appear non-viable will recover with time
and appropriate management. Although a substantial area of necrosis
affecting a limb may be an indication for immediate fasciotomy in order to
salvage the limb.

It should be noted that re-warming of the affected part should not be
attempted until the patient is in a safe and warm environment where there
is no possibility of re-freezing. Re-freezing produces even more tissue
necrosis and increases dramatically the extent of injury. If frostbite
occurs in a remote location it is better to let a patient walk upon a
frostbitten foot to a safe area than to attempt re-warming.

Key points of frostbite management

• Do not attempt to thaw tissues until patient is in a safe and warm

• Do not allow further freezing

• Resuscitate if required

• Re-warm at 38-42oC for 30 mins in a whirlpool device or bath with
chlorhexidine solution

• Leave blisters intact

• Light dressings

• Elevate area

• Strictly non-weight bearing on frostbitten tissues

• Smoking cessation

• Twice daily re-warming until signs of tissue healing

• Discuss with a specialist unit

Competing interests:
None declared

Competing interests: No competing interests

17 January 2010
Marc-James Hallam
Plastic surgery speciality registrar
Tania Cubison
Queen Victoria Hospital, Holyte Road, East Grinstead, West Sussex, RH19 3DZ