Hypothermic ( Adult ) Patients in Hospital - Management

Publication: 25/01/2012  --
Last review: 04/09/2018  
Next review: 01/09/2021  
Clinical Guideline
CURRENT 
ID: 2833 
Approved By: Trust Clinical Guidelines Group 
Copyright© Leeds Teaching Hospitals NHS Trust 2018  

 

This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

The Management of Adult Hypothermic Patients in Hospital

Summary

Criteria for use

Adult hypothermic patients admitted to Leeds Teaching hospital with gradual urban (non- immersional) hypothermia. Use ALS guidance in a cardiac arrest.

Diagnosis

  • Mild 35-32°C
  • Moderate >32-28°C
  • Severe <28°C

Temperature can be recorded using tympanic measurements in patients with a perfusing rhythm (i.e. patients not in cardiac arrest) in the hospital environment.

See table below for clinical features

Remember hypothermia may be a secondary diagnosis. Consider underlying problems such as stroke which may only become apparent on rewarming.

Investigations

  • Bloods: FBC, U+E, LFT, CK, glucose, TFT’s, CRP, lactate
  • ABG’s
  • CXR
  • ECG

Management

Mild 35-32°C

  • Warm with single layers of blankets and cover head with blankets or a hat
  • Warm drinks if swallow safe
  • Nurse in warm environment (25-30°C) - side room if possible.
  • 4 hourly obs

Moderate >32-28°C

  • Active rewarming with forced air (Bair hugger) and warmed IV fluids. Other methods may be considered- see below
  • Passive measures of rewarming as described above
  • 1 hourly obs

Severe <28°C

  • Consider cardiopulmonary bypass if patient is not responding to methods described above. Contact the cardiothoracic registrar on-call at LGI.
  • Continuous cardiac monitoring in ED resus/HDU/ITU

Rewarming rate

Rate of rewarming in patients with moderate / severe hypothermia should not exceed 0.5°C/h due to the risks of precipitating cerebral/pulmonary oedema.

Handle with care

Rough handling may precipitate ventricular arrhythmias in moderate/ severely hypothermic patients. This is especially important at temperatures <30°C when arrhythmias may not respond to defibrillation/ cardio active drugs.

Aims

  • To improve the management of patients presenting to LTHT with urban (non- immersional) hypothermia.

Objectives

  • To provide evidence based guidelines for the management of mild, moderate and severe hypothermia.
  • To clarify safe methods of re-warming in adults with gradual onset hypothermia.
  • To increase professional awareness of the impact of cold weather especially on the elderly population.

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Background

Gradual urban hypothermia is associated with significant mortality and morbidity especially in the elderly population. There is little robust evidence to support the various methods of rewarming and management is varied. These guidelines aim to provide a clear standard and update the 1998 Elderly Medicine hypothermia guidelines for Leeds Teaching Hospitals. These guidelines have also been approved for use in the adult population.

Risk Factors for hypothermia:

Elderly population- Older people have a lower basal metabolic rate (Guyton, 2000, Grimley, 2000), impaired vasoconstrictor response to cold (Collins, 1977) and less awareness of ambient cold temperatures all of which predispose to hypothermia.

Decreased mobility- Reduced mobility often results in reduced muscle mass which is associated with impaired shivering response. These patients are less likely to be able to generate heat from mobilisation. (Epstein, 2006)

History of falls and unsteadiness- (Otty et al 1987)

Living alone- (Darowski et al 1991)

Cold weather- Not necessarily cold environment. (Darowski et al 1991)

Dementia- Awareness of the cold and solutions to keeping warm are impaired in dementia. (Kibayashi et al, 2003)

Malnutrition- Reduced muscle and fat reserves are associated with a lower basal metabolic rate (Bastow et al, 1983).

Sepsis- Sepsis is associated with cutaneous vasodilatation and may therefore result in heat loss. Further, cytokine release associated with sepsis may impair thermoregulation. (Lewis et al, 1981, Aarons et al 1999)

Poor quality accommodation- Poor housing may increase the risk of hypothermia especially in cold weather.

Hospital related- There is evidence that older people are at risk when transferring from warm environment e.g. ward to colder one e.g. other clinical department (Watson, 1996). Additionally surgical patients are at risk of hospital acquired hypothermia. (Moddeman, 1991)

Others- Hypothyroidism, alcohol, burns, dermatitis, severe psoriasis, drugs e.g. chlorpromazine.

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Diagnosis

Definitions

Hypothermia can be defined as an unintentional drop in core body temperature below 35° (Danzyl, 2007). It is further classified as [C]:

  • Mild 35 -32°C,
  • Moderate >32-28°C
  • Severe <28°C

Symptoms

The cold body attempts to regulate the body temperature by shivering to increase heat production and by increasing peripheral vasoconstriction to reduce heat loss. (Epstein, 2006) In continued cold exposure these mechanisms are exhausted and hypothermia develops.

Table 1

Temperature

Signs and symptoms

Mild 35-32°C

Initial-Shivering, tachycardia, tacypnoea, vasoconstriction.
Continued hypothermia-Apathy, slurred speech, ataxia, impaired judgement, cold induced diuresis
Paradoxical undressing may result

Moderate >32-28°C

Reduced GCS, bradycardia, atrial arrhythmia’s, reduced respiratory rate, hypo reflexia, dilated pupils, reduced gag reflex
No shivering
J waves on ECG present.

Severe <28°C

Coma, apnoea, asystole, ventricular arrhythmia, non- reactive pupils, pulmonary oedema, oligouria.


(Epstein, 2006)

Complications of hypothermia

  • Cardiac arrhythmias- hypothermia causes myocardial irritability, < 30°C the risk of ventricular arrhythmias is particularly high.
  • Aspiration pneumonia- increased respiratory secretions associated with hypothermia and decreased respiratory rate increases the risk of aspiration pneumonia.
  • Impaired liver function- risk of toxicity with drugs metabolised by the liver.
  • Pancreatitis/ pancreatic damage

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Investigations

Temperature- Tympanic (Edge, 1993 [B]) or rectal temperature measurements are appropriate in the hospital setting but the method of measurement should remain the same throughout. (Robinson, 1998; Lefrant, 2003)[C]. Rectal temperature readings may be more accurate at recording <28°C. [D]

Bloods- U+E’s, FBC, CRP, TFTs, LFT’s, CK, lactate, Glucose [C]

Coagulation- Hypothermia causes a coagulopathy that is difficult to detect on laboratory assays which are done at 37°C, as at this temperature they resolve.

Blood cultures- Hypothermia is commonly associated with sepsis in older people and blood cultures should be taken if sepsis is suspected. Please see LTHT guidance for blood culture sampling in adults.[C]

CXR- To diagnose underlying/ associated pneumonia or pulmonary oedema.[C]

ECG- J waves may be present. As the core temperature cools bradycardia may develop followed by atrial fibrillation followed by ventricular fibrillation prior to the development of asystole. (Mattu et al 2002)These arrhythmias with the exception of ventricular fibrillation will resolve with rewarming.[C]

ABG’s- Hypothermia is associated with metabolic acidosis possibility due to lactic acid production associated with poor tissue perfusion. Type 1/2 respiratory failure may be identified. (Epstein, 2006 [C])

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Management

For patients in cardiac arrest follow ALS guidelines : http://www.resus.org.uk/pages/als.pdf

  • Gradual urban hypothermia:
    General measures
    • Resuscitate patient, get senior help (SpR/ST3 or above) and involve ITU if required/ appropriate.
    • In some circumstances e.g. a terminal illness/ event it may be appropriate to consider a less active/palliative approach. Senior doctors and family should be involved in such decisions.

      Airway
    • Assess airway and protect in the unconscious patient. (Soar,2010)[C]
      -Give supplemental O2 even if sats normal (e.g. 24%) as respiratory rate may fluctuate and adequate oxygenation will stabilise the myocardium. (Soar, 2010)[C]

      Breathing
    • Check respiratory rate.
    • Examine for underlying pneumonia/ pulmonary oedema.

      Circulation
    • Check pulse, BP, ECG and urine output.
    • Secure IV access and take bloods.
    • Aim to maintain systolic BP of 100mmHg and to support urine flow >60ml/h. Assess fluid status; hypothermic patients are often volume depleted due to long lie or dehydration. Warmed (42°C) fluids have been shown to be effective in warming patients (Kornberger,1999 [B])but larger volumes may be required as they promotes vascular dilation.(Epstein, 2006)

      Disability
    • Check blood glucose.
    • Check pupils.
    • Assess conscious level- Consider secondary causes e.g. head injury and overdose, especially if degree of impaired consciousness is out of proportion to the degree of hypothermia. (Mechem and Danzl,2011[C])
    • Be aware that signs of a stroke may only become apparent after rewarming.
    • Examine for sepsis-Hypothermia is an independent predictor of mortality in elderly patients with sepsis.(Tiruvoipati et al, 2010 [B]) Infection should therefore be identified and treated promptly but there is no evidence to support routine use of antibiotics.(Moss, J,1986 [C]; Saphar,1993[C])

      Environment
    • Consider bed rails if restless or confused.
    • Avoid unnecessary movements/ rough handling in patients with moderate/ severe hypothermia as this may provoke ventricular arrhythmias (AHA, 2005).
    • Prevent further heat loss by catheterisation and avoid unnecessary washing of patient.

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Rewarming

Rates of rewarming should not exceed 0.5°C/h especially if hypothermia has developed gradually as there is a risk of cerebral/ pulmonary oedema. (Lloyd, 1996 [C])

For most patients with mild hypothermia rewarming can be achieved by using single layers of blankets and covering the head (Danzl, 1994 [C]). Space blankets should not be used as there a risk of insulating a cold body which is not generating heat. (Chadwick and Gibson, 1997 [C])

Patients with moderate / severe hypothermia should receive active external rewarming with forced air (Bair hugger) and warmed IV fluids. Bair huggers are available on the acute admission wards and fluids can be warmed to 42°C using a blood warmer (ED). Previously there have been reported claims of significant after drop* with these methods but the European Resuscitation Council (2010) concluded that “even in severe hypothermia no significant after drop or malignant arrhythmias have been reported”.

Other methods of active re warming include:

  • Warm humidified oxygen or air (Danzl, 1994 [C])
  • Peritoneal dialysis or pleural cavity lavage with warm fluids (Danzl, 1994 [C])
  • Cardiopulmonary bypass is available at the LGI and should be considered for all cases of rapid immersional hypothermia. Contact the cardiothoracic registrar on call if appropriate as this is the best method of raising core body temperature rapidly.

*After drop-During rewarming the core temperature may drop (after drop) as a result of peripheral vasodilatation as cold blood is released into the core. A randomised controlled study by Steele et al, 1996 suggested this was probably clinically insignificant and supported the use of the Bair Hugger.

Handle with care

Rough handling may precipitate ventricular arrhythmias in moderate/ severely hypothermic patients. This is especially important at temperatures <30°C when arrhythmias may not respond to defibrillation/ cardio active drugs. (AHA,2005; ERC,2010[C])

Mild Hypothermia (35°C- 32°C)

Rewarming-Patients with mild hypothermia should be treated by passive rewarming i.e., warm clothes including a hat/ blankets to cover head, single layers of blankets and warm drinks if able to swallow safely. (Collins 1995, Watson, 1996). If this fails consider active methods of rewarming.

Nursing Environment- The patient should be nursed in a warm environment ideally 25-30°C. A side room is preferable with limited stimuli to reduce the risk of precipitating an arrhythmia. (AHA, 2005[C]) Avoid unnecessary washing of patient and consider catheterisation if incontinent to prevent heat loss.

Monitoring- Tympanic temp, pulse, BP, RR measured every 4 hours.

Moderate (>32°C-28°C)

Rewarming- Patients should be actively rewarmed using forced air (Bair hugger) and warmed IV fluids (42°) aiming to increase the core temperature gradually by 0.5°C/ hour. These may be used in addition to passive methods of rewarming described above. Other methods of active rewarming may be considered (see above).

Nursing Environment- The patient should be nursed in a warm environment ideally 25-30°C. If possible a side room should be used with limited stimuli to reduce the risk of precipitating an arrhythmia. (AHA, 2005[C])Avoid unnecessary washing of patient to conserve heat. [D]

Monitoring- Continuous cardiac monitoring should be in place to quickly detect arrhythmias. 1° obs including temp, RR, BP should be taken. The patient should be catheterised and hourly urine output monitored.[D]

Severe (<28°C)

Rewarming- Active methods of rewarming should be used as described for moderate hypothermia but if standard rewarming time could be prolonged consider cardio-pulmonary bypass. (Silfvast, 2003[B]).

Nursing environment- Patients should be managed in the ED resus or HDU as they require one to one nursing. Avoid unnecessary washing of patient to conserve heat.[D]

Monitoring- Continuous cardiac monitoring should be in place to quickly detect arrhythmias. 1° obs including temp, RR, BP should be taken. The patient should be catheterised and hourly urine output monitored.[D]

Secondary Prevention- How to keep warm

As health care professions we have a responsibility to advise patients how to stay warm, especially during the winter months.
Useful advice:

  • Eat well
  • Keep mobile
  • Dress in warm clothes
  • Several layers of clothing instead of one thick layer

There are many useful resources where patients and carers can access information. Age UK and the Department of Health both produce leaflets giving advice to older people on ways to keep warm, how to save money on energy bills and how to claim grants such as the winter fuel allowance and grants towards insulation.

www.ageuk.org.uk/health-wellbeing/keeping-your-body-healthy/winter-wrapped-up/preparing-for-winter
www.gov.uk/government/publications/keep-warm-keep-well-leaflet-gives-advice-on-staying-healthy-in-cold-weather

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Provenance

Record: 2833
Objective:

Aims
• To improve the management of patients presenting to LTHT with urban (non- immersional) hypothermia.

Objectives
• To provide evidence based guidelines for the management of mild, moderate and severe hypothermia.
• To clarify safe methods of re-warming in adults with gradual onset hypothermia.
• To increase professional awareness of the impact of cold weather especially on the elderly population.

Clinical condition:

Hypothermia

Target patient group: Adult patients presenting with gradual onset urban hypothermia (non immersional)
Target professional group(s): Secondary Care Doctors
Secondary Care Nurses
Allied Health Professionals
Adapted from:

Evidence base

Age UK. Winter wrapped up campaign  2017. Available at www.ageuk.org.uk/Documents/EN-GB/Information-guides/AgeUKIG27_Winter_wrapped_up_inf.pdf?epslanguage=en-GB?dtrk=true (Accessed online August 1st 2018)

American Heart Association. American Heart Association Guidelines for Cardiopulmonary Resuscitation and Emergency Cardiovascular Care. Circulation 2005;112:IV-136-IV-138.

Arons MM, Wheeler AP, Christman BW, Russell JA, Schein R, et al. Effects of ibuprofen on the physiology and survival of hypothermic sepsis. Ibuprofen in sepsis study group. Critical Care Medicine 1999;27:699-707

Bastow MD, Rawlings J, Allison SP. Under nutrition, hypothermia, and injury in elderly women with fractured femur: an injury response to altered metabolism? Lancet 1983;i:143-6

Chadwick, S., A.Gibson. Hypothermia and the use of space blankets: a literature review. Accident and Emergency Nursing. 1997. 5(3) pp122-125

Collins KJ, Dore C, Exton-Smith AN, Fox RH. Accidental hypothermia and impaired temperature homeostasis in the elderly. BMJ 1977; i: 353-6

Darowski, A.,Z.Najim, J.R.Weinberg, A.Guz. Hypothermia and infection in elderly patients admitted to hospital. Age Ageing. 1991;20:100-6

Danzl, D. Accidental hypothermia. In: Auerbach P, editor. Wilderness medicine.
St. Louis: Mosby; 2007. p. 125–60

Department of Health. Keep warm keep well 2017. Available at www.gov.uk/government/publications/keep-warm-keep-well-leaflet-gives-advice-on-staying-healthy-in-cold-weather. (Accessed online August 1st 2018)

Edge G, Morgan M. The genius infrared tympanic thermometer: an evaluation for clinical use. Anaesthesia 1993; 48:604-7

Epstein E, Anna K. Accidental hypothermia. BMJ 2006; 332:706-9

Soar, J.,G. D. Perkins, G.Abbas, A. Alfonzo, A. Barelli, J. J.L.M. Bierens, H. Brugger, C. D. Deakin, J.Dunning, M. Georgiou, A. J. Handley, D. J. Lockey, P. Paal, C. Sandroni, K. Thies, D. A. Zideman, J. P. Nolan. European Resuscitation Council Guidelines for Resuscitation 2010 Section 8. Cardiac arrest in special circumstances: Electrolyte abnormalities, poisoning, drowning, accidental hypothermia, hyperthermia, asthma, anaphylaxis, cardiac surgery, trauma, pregnancy, electrocution. Published online 19 October 2010, pages 1400 - 1433

Grimley EJ, Franklin Williams T, Lynn Beattie B, Michael J-P Wilcock GK. Oxford textbook of geriatric medicine. 2nd edition. Oxford: Oxford university press, 2000

Guyton,A.C, J.E.Hall. Medical physiology.10th ed. Philidelphia, PA: WB Saunders, 2000

Kornberger E, Schwarz B, Lindner KH, Mair P. Forced air surface rewarming in patients with severe accidental hypothermia. Resuscitation 1999; 41:105-11.

Kibayashi, K., Shojo H. Accidental fatal hypothermia in elderly people with Alzheimer’s disease. Med Sci Law 2003; 43:127-31

Lefrant, J.Y, L.Muller, J.E.de La Coussaye et al. Temperature measurement in Intensive care patients: comparison of urinary bladder, oesophageal, rectal, Auxiliary and inguinal methods versus pulmonary artery core method. Intensive Care Med 2003; 29:414–8.

Lewin, S., L.R.Brettman, R.S.Holzman. Infections in hypothermic patients. Archives Internal Medicine 1981; 141:920-5

Mattu, A., W.J.Brady, A.D.Perron. Electrocardiographic manifestations of hypothermia. Am J Emergency Medicine 2002; 20:314-326

Mechem, CC, D.F. Danzl. Accidental Hypothermia in adults. UpToDate Available at www.uptodate.com (Accessed on line 29th December 2014)

Moddeman, G. The elderly surgical patient- A high risk for hypothermia. Aorn Journal 1991; 53(5); 1270-72

Moss, J. Accidental severe hypothermia. Surg Gynecol Obstet 1986;162:501-13

Otty, C, M.O.Roland. Hypothermia in the elderly: scope for prevention. BMJ 1987; 295:419-420

Robinson, J., J. Charlton, R.Seal, D.Spady, M.R.Joffres. Oesophageal, rectal, auxiliary, Tympanic and pulmonary artery pulmonary artery temperatures during cardiac surgery. Can J Anaesth 1998; 45:317–23.

Tiruvoipati, R., K.Ong, G.Himangsu, S.Arora, I.Carney, J. Botha. Hypothermia predicts mortality in critically ill elderly patients with sepsis. BMC Geriatrics 2010; 10:70 (accessed 14 Jan 2011 at: http://www.biomedcentral.com/1471-2318/10/70)

Safar P. Cerebral resuscitation after cardiac arrest: research initiatives and future directions. Annuals of Emergency Medicine 1993; 22:324-49

Silfvast, T.,V.Pettila. Outcome from severe accidental hypothermia in Southern Finland- A 10 year review. Resuscitation. 2003; 59:285-290

Watson, R. Hypothermia, Emergency Nurse. Winter 1995/96; 3(4):10-13

Evidence base:

  1. Meta-analysis, randomised controlled trials/systematic reviews of RCTs
  2. Robust experimental or observational studies
  3. Expert consensus
  4. Leeds consensus. (where no national guidance exists or there is wide disagreement with a level C recommendation or where national guidance documents contradict each other)

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Approved By

Trust Clinical Guidelines Group

Document history

LHP version 1.0

Related information

Not supplied

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