This section is ONLY an Adult protocol; however, the practitioner may find this protocol's information useful for pediatric patients and consider use of similar treatment with weight appropriate equivalent doses at their discretion.
Hypothermia may be the primary or secondary event; generally, if it is the primary problem, the outcome may be more favorable.
Severity of hypothermia is defined as
- Mild: >34°C (>93.2°F)
- Moderate: 30-34°C (86-93.2°F)
- Severe: <30°C (<86°F)
General issues
- Hypothermic patients will metabolize ACLS drugs more slowly and these may accumulate to toxic levels; therefore dosing interval should be prolonged
- Response to therapy may be quite limited until hypothermia is improved
- Bradycardia and very slow respirations are typical and may not require treatment
Modifications to ACLS/BLS and treatment for Hypothermia
- All patients
- Assess ABC's, place IV, monitor, vitals
- Provide standard supportive measures, including CPR, intubation, 100% O2 for all patients as indicated
- Remove wet clothing and move patient to warm environment
- Perform any needed immediate procedures (intubation, IV's) gently as VF may be precipitated
- Mild Hypothermia (>34°C)
- Passive rewarming by providing a warm dry environment
- No other modifications to ACLS/BLS.
- Moderate Hypothermia (30-34°C)
- Active external rewarming indicated, warmed IV fluids (43°C) and O2 (42-46°C).
- Patients in cardiac arrest should be given active internal rewarming
- Medications given at standard dose but dosing intervals spaced longer
- Severe Hypothermia (<30°C)
- Active internal rewarming indicated, warmed IV fluids (43°C) and O2 (42-46°C) also indicated.
- Patients in cardiac arrest should receive CPR
- Patients in VF should receive 1 defibrillation attempt; if unsuccessful, no further attempts until core temperature is 30-32°C
- ACLS Medications should generally be withheld until core temperature is >30°C
- Bradycardia is physiologic and generally should not be treated with medications or pacing
- Internal rewarming is typically through peritoneal lavage, chest tubes (bilateral) into which warmed saline (43°C) is circulated through, OR through extracorporeal blood warming with cardiac bypass.
- IV fluids are often needed (warmed) in severe hypothermia due to vasodilation
- Prolonged CPR until the patient's hypothermia has resolved and they still are not responding to therapy is indicated in many cases before cessation of efforts. This may not be the case when the hypothermia is the secondary process to a primary event.
Source: Circulation 2005;112. 2005 AHA Guidelines for CPR and ECC.