To reduce heat loss and aid re-warming the patient
was placed on a towel and enclosed in a recovery
warm air blanket attached to a ‘cocoon’ heater (AAS
Darvell, USA) (Figure 4). Warm air blankets provide
indirect active warming and were shown to minimise
hypothermia in anaesthetised cats in a study carried
out by Machon et al (1999). Archer (2007) and Clark
(2003) describe this as a preferable method to achieve
active warming compared with direct heat provided
by electric heat pads, hot water bottles or ‘hot hands’
(latex gloves filled with warm water), as thermal
burns are possible especially in the recumbent patient.
The towel underneath the patient acted as an
insulation layer to prevent heat loss via conduction.
Lamb (2009) describes other methods of insulation
such as bubble wrap, material or foil blankets which
she advises can reduce heat loss by 30%. Pre-warmed
intravenous fluids were used to encourage active core
warming. A study carried out by Dix et al (2006) highlighted
the importance of actively maintaining the
temperature of the fluids rather than just pre-warming
them due to the heat loss that occurs as the fluid
travels down the giving set. The most effective results
were achieved by pre-warming the fluids and the giving
set to 38oC, using a fluid heat retention bag over
the bag itself and wrapping 30 cm of a distal portion