Page 871 - Cote clinical veterinary advisor dogs and cats 4th

422 Heat Stroke/Hyperthermia

TREATMENT • Gastrointestinal (GI) protectants such PEARLS & CONSIDERATIONS
as pantoprazole 1 mg/kg, IV, q 12-24h; Comments
Treatment Overview
VetBooks.ir Mild hyperthermia requires no treatment q 12-24h DOG or 5 mg/CAT PO q 12-24h; • Hyperthermia due to excitement or exercise
omeprazole (if no vomiting) 0.7 mg/kg PO
does not require active cooling if the animal
sucralfate (if no vomiting) 250-1000 mg PO
beyond providing a cool environment. Heat
stroke requires active cooling efforts, treatment
retains normal mentation and behavior.
of underlying disorders contributing to heat q 6-8h • Self-cooling efforts (e.g., panting) cease with
generation (e.g., control seizures in status Possible Complications severe heat stroke; this should not confuse
epilepticus), aggressive supportive care, and • DIC the diagnosis in an overheated animal with
careful monitoring for and management of • AKI (oliguria/anuria) mentation changes suggesting heat stroke.
complications such as DIC, AKI, sepsis, or • GI sloughing/bacterial translocation/diarrhea/ • Aggressive early cooling is warranted for heat
cerebral edema. melena stroke.
• Acute hepatic injury • Avoid overcorrection of body temperature
Acute General Treatment • MODS and hypothermia.
• For obtunded/comatose patients or those • Cerebral edema/altered neurologic status • Multiple organ failure and DIC are common
with upper airway obstruction, endotracheal • Bone marrow dysfunction with heat stroke. The best chance of recovery
intubation can improve gas exchange, involves 24-hour care with access to appropri-
facilitate oxygen supplementation (p. 1146), Recommended Monitoring ate monitoring tools.
reduce the risk of aspiration pneumonia, and • Frequent recheck of vital parameters until
enable additional heat dissipation. stable; serial neurologic evaluation Prevention
• Lukewarm (room temperature) intravenous • Continuous electrocardiographic (ECG) Avoid exposing the animal to high ambient
(IV) fluids and cool water baths (avoid ice monitoring for changes in heart rate or temperatures or prolonged physical activity.
water, which causes peripheral vasoconstric- worsening arrhythmia (p. 1096)
tion). Fans improve convective heat loss. • Blood pressure monitoring (goal: sys- Technician Tips
Additional cooling techniques include tolic > 100-120 mm Hg) and blood • Avoid jugular venipuncture until coagulation
infusion of the bladder with sterile, lukewarm glucose assessment (goal: 80-140 mg/dL status can be ascertained.
fluid, or cold-water gastric lavage (using [4.4-7.8 mmol/L]) q 2-4h as clinically • Avoid hypothermia by discontinuing
an orogastric tube in an endotracheally indicated) (p. 1065) active cooling when temperature reaches
intubated patient), or enema. • Urine output (goal: > 1-2 mL/kg/h), serial 39.2°C-39.4°C (103°F-103.5°F).
• Active external cooling should be discon- rechecks of urinalysis, serum blood urea • Monitor for recurrent respiratory distress
tinued after the rectal temperature reaches nitrogen (BUN) and creatinine on extubation, particularly in animals
39.2°C-39.4°C (103°F-103.5°F) to reduce • Blood gas evaluation, as clinically indicated with brachycephalic syndrome or laryngeal
the risk of severe hypothermia. Rectal • Recheck of coagulation times if initially paralysis. Prolonged intubation, temporary
temperature monitoring is not reliable prolonged or evidence of bleeding (pp. 433 tracheostomy (p. 1166), or definitive airway
for patients who have received cool water and 1325) correction may be required.
enemas. • Recheck of platelet count • Placement of a urinary catheter and closed
• Treat hypoglycemia (p. 552) if present. collection system enables frequent, accurate
• Mannitol 0.5-1 g/kg IV slowly over 15-20 PROGNOSIS & OUTCOME calculation of urine output and characteriza-
minutes or 7% NaCl 1-3 mL/kg slow IV tion of urine (color, turbidity).
if increased intracranial pressure or cerebral • The prognosis associated with heat stroke
edema is suspected. varies widely, depending on clinical severity Client Education
• For seizures: diazepam 0.2-0.5 mg/kg at hospital admission. Animals recovering • Educate about the dangers of leaving pets
IV, repeated up to 3 times; if ineffective, from heat stroke may be at increased risk in cars or prolonged exercise on hot days or
phenobarbital 2- 4 mg/kg IV q 30 minutes for future heat stroke. if upper airway diseases exist.
up to a total dose of 16 mg/kg or propofol • Initial body temperature has NOT been • Clinical signs such as weakness and panting
continuous-rate infusion 2-6 mg/kg IV correlated with outcome. in hot weather may be an emergency;
bolus, followed by 0.1-0.2 mg/kg/min. Some • The following have been associated with a institute cooling measures, and consult a
neurologists advocate levetiracetam (pp. 301 poor prognosis: veterinarian.
and 903). ○ Coagulopathy at admission (>150% • Dousing the animal with cool water before
• Ventricular arrhythmias (pp. 1033 and 1457) prolonged PT or aPTT compared with transport can initiate cooling in patients with
are treated if necessary. the upper limit of the reference range) heat-related illness (heat exhaustion or heat
• Fresh-frozen plasma (10-15 mL/kg) should ○ Fibrinogen < 172 mg/dL or prolonged stroke).
be administered if coagulation times are aPTT at 24 hours after presentation
prolonged and there is clinical evidence of ○ Nucleated red blood cells > 18/100 white SUGGESTED READING
bleeding (p. 1169). blood cells Bruchim Y, et al: Heat stroke in dogs: a retrospective
• Broad-spectrum antibiotics such as cefazolin ○ Persistent hypoglycemia study of 54 cases (1999-2004) and analysis of risk
22 mg/kg IV q 8h, enrofloxacin 5-20 mg/ ○ Serum creatinine (>1.5 mg/dL [> 132.6 factors for death. J Vet Intern Med 20(1):38-46,
kg IV q 24h, maximum 5 mg/kg in cats, mmol/L]) after 24 hours 2006.
and metronidazole 10-15 mg/kg IV q 12h ○ Seizures AUTHOR: Geoff Heffner, DVM, DACVECC
may be indicated because of venous pooling ○ Delayed admission EDITOR: Benjamin M. Brainard, VMD, DACVAA,
within the splanchnic circulation and risk ○ Obesity DACVECC
for bacterial translocation.

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