Field care of a cold victim Peter Lundgren, MDOtto Henriksson, MD Department of Surgery and Perioperative Sciences, Umea University, Sweden

Peter Lundgren, MD Otto Henriksson, MD Prehospital Cold Environment  Unsufficient / wet clothing  Entrapment / Immobilisation  Injuries / Illness / Exhaustion  Alcohol /drugs  Exposure

Peter Lundgren, MD Otto Henriksson, MD Recognition and staging of a cold victim ( I ) 32 – 35 C Light shivering Cold and pale skin Increased diuresis Impaired dexterity Intense shivering Increased breathing and pulse Impaired coordination and strength Confusion, agitation, apathetic Shivering diminished Impaired consciousness Decreased breathing and pulse Unconscious No signs of life ( II ) 28 – 32 C ( III ) 24 – 28 C ( IV ) < 24 C 35 – 37 C

Peter Lundgren, MD Otto Henriksson, MD Recognition and staging of a cold victim ( I ) 32 – 35 C Light shivering Intense shivering Shivering diminished Impaired consciousness Unconscious No signs of life ( II ) 28 – 32 C ( III ) 24 – 28 C ( IV ) < 24 C 35 – 37 C Cold discomfort Increased oxygen consumption Impaired blood clotting Increased mortality x3-4 Rapid core cooling Ventricular fibrillation Asystole

Peter Lundgren, MD Otto Henriksson, MD  Rescue and examine  Address life threatening conditions  A B C D E Basic Prehospital Care

Peter Lundgren, MD Otto Henriksson, MD AAirway maintenance with cervical spine protection as usual BOxygen – better cold oxygen than no oxygen CPalpation of pulses - warm hand > 1 min Warm iv. fluids (glucose) Horizontal position Handle gently DNot dead until warm and dead (or obviously dead) Initial assessment and management

Peter Lundgren, MD Otto Henriksson, MD EStop further cooling (prevent afterdrop)  Shelter  Remove wet clothing (if possible)  Insulate from the cold environment  Prevent local cold injuries  Apply exogenous heat sources Warm high calorie beverages Exercise Initial assessment and management

Peter Lundgren, MD Otto Henriksson, MD Insulation Purpose of insulation  Reduce heat loss  Contain endogenous heat production Influencing factors  Ambient temperature  Wind  Moisture  Handling and durability

 Climatic chamber  Thermal manikin on spineboard  Different wind conditions  Ambient temperature  Manikin skin temperature  Heat Flux Thermal insulation in wind conditions

Peter Lundgren, MD Otto Henriksson, MD IREQ 70 W/m °C Rescue Blanket Bubblewrap Woollen blanket Reflective blanket Polyester blanket Thermal insulation in wind conditions Thermal insulation (clo) Wind (m/s)

Peter Lundgren, MD Otto Henriksson, MD Determining characteristics  Thickness  Windproofness  Compression resistance Adjust insulation according to  Ambient temperature  Wind conditions  On scene durations Thermal insulation in wind conditions

Peter Lundgren, MD Otto Henriksson, MD  Removal of wet clothing  Use of a vapour barrier Is it important? Thermal insulation in wet conditions

Peter Lundgren, MD Otto Henriksson, MD In shivering subjects:  reduces the amount of shivering  less stress on the body  comfort In non-shivering subjects:  attenuates afterdrop  rewarming Active warming

Peter Lundgren, MD Otto Henriksson, MD To the chest or upper back (neck, armpits, groins); close proximity to the heart and lung circulation Active warming

Peter Lundgren, MD Otto Henriksson, MD Torso Warming Study  Cold water immersion  Shivering inhibited with meperidine  Core temp (esophageal)  Skin temp and heat flux  Oxygen consumption  Puloxymetry  ECG  Dried and covered  Heat applied (120 min)

Peter Lundgren, MD Otto Henriksson, MD Charcoal Heater

Peter Lundgren, MD Otto Henriksson, MD Chemical Heat Pad

Peter Lundgren, MD Otto Henriksson, MD Hot Water Bag

Peter Lundgren, MD Otto Henriksson, MD Core Temperature Water Bags ** Chemical Heat Pad* Charcoal Heat Pac* Spontaneous * Start active warming Start cooling Inhibit shivering

Peter Lundgren, MD Otto Henriksson, MD  Heat x surface area x time  Portable  No external energy supply  Adapted to scenario and organisation Heat sources

Peter Lundgren, MD Otto Henriksson, MD Practical aspects

Peter Lundgren, MD Otto Henriksson, MD Peter Otto Prehospital care in a cold environment Research and Development