9.14. HYPERTHERMIA/IMPACT OF WARM ENVIRONMENT

Related titles

Hyperthermia, heat convulsions, heat exhaustion, heat syncope, heat edema, heat stroke.

Definition

1. Heat spasms are minor muscle spasms, usually in the legs and abdominal wall. Body temperature is normal.
2. Heat exhaustion – serious depletion of water and salt reserves in the body. When it worsens, it leads to tachycardia, hypotension, increased body temperature and very painful convulsions. Symptoms include headache, nausea and vomiting. Heat exhaustion can turn into heat stroke.
3. Heat stroke – occurs as a result of stopping the body’s cooling mechanism (sweating) due to temperature overload and/or electrolyte imbalance. The patient’s body temperature is usually above 40 degrees. In the absence of a thermometer, heat stroke can be distinguished from heat exhaustion in the presence of an altered state of consciousness.
4. Heat syncope is a transient loss of consciousness with spontaneous recovery of consciousness due to exposure to a warm environment.
5. Heat edema – swelling of a limb due to fluid accumulation.

Purpose of assistance

1. Cooling and restoration of water balance.
2. Decreasing the risks of decompensation.
3. Reducing the risks of an excited state and uncooperative behavior.

Description of the patient

Inclusion criteria

1. Heat cramps.
2. Heat exhaustion.
3. Heat stroke.
4. Heat syncope.
5. Heat edema.
6. Abuse of stimulant drugs.
7. Delirium (see Agitated or Aggressive Patient/Behavioral Emergencies) guideline.

Exclusion criteria

1. Fever due to infectious or inflammatory conditions.
2. Malignant hyperthermia.
3. Serotonin syndrome.
4. Malignant neuroleptic syndrome.

Providing assistance to the patient

Status assessment

1. Review:

a) age;
b) oral intake of food and water;
c) medicines;
d) alcohol consumption;
e) use of prohibited narcotic substances;
e) overdose;
e) risk of addiction;

2. Environmental assessment:

a) temperature and humidity around;
b) level of effort;
c) duration of stay in the risk zone;
d) clothing;
e) closed space.
Children who were left in a closed car, in which there is a change in the state of consciousness and an elevated body temperature, should cause suspicion of the presence of hyperthermia.

3. Associated symptoms:

a) convulsions;
b) headache;
c) orthostatic symptoms;
d) nausea;
e) weakness ;
e) changes in consciousness, including:

• • • • disorientation;
      • coma;
      • convulsions;
      • psychosis.

4. Vital signs:

a) temperature – usually above 40◦ C (if a thermometer is available);
b) skin:

• • • • reddened and hot;
      • dry or wet;
      • signs of sunburn of the first or second degree;

c) Other signs of poor perfusion/shock.

Treatment and intervention

1. Move the patient to a cool place and away from the sun or any external heat source.

2. Remove as much clothing as possible (if possible) and loosen all restraint straps.

3. If the patient is conscious and agitated, give small sips of cool liquids.

4. If the state of consciousness is changed, check the glucose level.

5. Control the airways.

6. Apply a cardiac monitor and record all vital signs and level of consciousness.

7. If the body temperature is above 40 degrees or the state of consciousness is altered, start active cooling by.

7.1. Immersion in a cool bath gives the fastest cooling, but it is not always available for EMD – in the event of the appearance of trbloating during cooling:

a) for adults:
Midazolam

• • • • 2.5 mg IV or nasally, repeated administration (once) after 5 minutes
        OR
      • 5 mg IV, repeated administration (once) after 10 minutes
        Lorazepam
      • 1 mg IV, repeated administration (once) after 5 minutes
        OR
      • 2 mg IV, repeated administration (once) after 10 minutes
        Diazepam – 2 mg IV, repeated administration (once) after 5 minutes;

b) children
Midazolam (single maximum dose – 1 mg)

• • • • 0.1 mg/kg
        OR
      • 0.2 mg/kg nasal/in/m
        Attention: a concentration of 5 mg/ml is recommended for nasal/in/m use
        Lorazepam (one-time maximum dose – 1 mg)
      • 0.1 mg/kg IV or IV/m
        Diazepam
      • 0.1 mg/kg IV (single maximum dose – 2.5 mg)
      • single repeated administration, maximum total dose (in/in/m) 5 mg
        OR
      • 0.5 mg/kg rectally (single maximum dose – 10 mg).

7.2. Continue to moisten the affected skin area with water while simultaneously blowing the patient (most effectively).

7.3. You can apply ice packs to the trunk, however, this is less effective than vaporization.

7.4. DO NOT wear wet clothing as it can trap heat and reduce cooling by evaporation.

8. Cooling therapy should continue until the body temperature drops below 39°C and the patient has improved consciousness.

9. Provide IV access in a heatstroke situation – administer a bolus of cold infusion solutions at a volume of 20 mg/kg and reduce it to 10 ml/kg/h after stabilization of vital signs.

10. Monitor for the onset/presence of arrhythmias or collapse (see guidelines under Cardiovascular Problems).

11. Treat convulsions (according to the instruction “Convulsions”).

12. All patients with heat-related emergencies (including heat stroke) should be hospitalized.

Patient safety

Use physical restraints on the patient (see Agitated or Aggressive Patient/Behavioral Emergencies) to secure the vascular access catheter.

Useful information for training

Key points

1. The risk group includes newborn children, infants, the elderly, patients with mental disorders.

2. Additional risk factors can be:

a) prescribing over-the-counter herbal supplements;
b) cold medicines;
c) heart medicines;
d) diuretics ;
e) drugs for mental illnesses;
e) drug abuse;
e) accidental or intentional drug overdose.

3. Thermal damage can occur as a result of increased environmental temperature or prolonged physical exertion, or a combination of both factors.
Environments with temperatures above 30 degrees and humidity above 60% are the most risky.

4. Heat stroke is associated with cardiac arrhythmias that do not depend on the intake/overdose of narcotic drugs.
Heat stroke is also associated with the appearance of brain edema.

5. Be sure to look for other possible causes of altered consciousness, such as glucose or, in certain cases (endurance events), hyponatremia due to exercise (especially in patients with altered consciousness, normal glucose, and normal body temperature).

6. Controversial (ambiguous) points – shivering can occur during the treatment of heat stroke:

a) it is not known for certain how harmful shivering is in patients with heat stroke;
b) cooling should be carried out until normalization of the state of consciousness and body temperature is achieved;
c ) treat tremors with the methods described above;
d) the results of the study do not show the effectiveness of one of the benzodiazepine drugs over others.

7. Hyperthermia caused by unnatural factors has characteristic symptoms and signs:

a) fever and delirium;
b) thyrotoxic crisis;
c) blow fever;
d) lesions or tumors of the central nervous system;
e) a dangerous effect of the use of the drug – neuroleptic malignant syndrome, malignant hyperthermia;
e) changes in consciousness without the presence of hyperthermia in certain cases may indicate hyponatremia due to physical exertion.

8. There is no evidence of the need to use EMD orthostatic vital signs.

Corresponding evaluation results

1. Warning signs – fever, loss of consciousness.
2. Glucose level with altered state of consciousness.

Key elements of documentation

1. Evaluation of the condition includes all types of drugs/drugs used by the patient and a detailed description of previous medical history.
2. Conducting an environmental assessment.
3. Selected and applied cooling means.
4. Making a decision on the use of protective measures.
5. Decision-making regarding monitoring of airways, breathing and circulation.

Criteria for the effectiveness of aid provision

1. Blood sampling for glucose level analysis.
2. Introduced fluids for hypotension.
3. Actions to reduce body temperature.
4. Overview of all manifestations of decompensation during the provision of EMD.