Environmental

Rapid Review

• Background
  • Dog bites can cause extensive tissue damage and infection with pasteurella, staph, strep, and Capnocytophaga species. 
• Signs/Symptoms
  • Typically have a ragged, torn appearance. 
  • Infected bites may become erythematous, swollen, and tender
• Diagnosis
  • Clinical diagnosis based on history/physical exam
• Treatment
  • Wound irrigation with or without closure.
  • Rabies and tetanus prophylaxis. Consider antibiotics (ex. Augmentin) for high-risk wounds.
• Disposition
  • Most patients can be discharged with antibiotics and follow-up in 24-48 hours for wound check.
  • If concern for rabies, patient will need to return on days 3, 7, and 14 for repeat vaccinations. 

Pearls

• In general, these wounds should be left open to heal via secondary intention if able.
• Rabies is extremely rare in domesticated animals. If a domesticated, healthy appearing dog bit the patient and is able to be observed for 10 days for signs of rabies, then rabies post exposure prophylaxis is not immediately needed.

Deep Dive

• Dog Bite Management: The Evidence (First 10 EM)

Rapid Review

• Background
  • Defined as experiencing respiratory impairment from submersion or immersion in a liquid
  • In addition to hypoxia, may also be associated with hypothermia, fluid aspiration, and spinal injuries
• Signs/Symptoms
  • SOB, respiratory failure, AMS
  • Intercostal retractions, cyanosis 
• Diagnosis
  • Clinical diagnosis
  • Pulse oximetry, ABG, and CXR can help determine severity. Consider CT head/spine if associated with trauma.
• Treatment
  • Resuscitate patients in cardiac arrest with special emphasis on ventilations
  • For non-arrest patients, manage hypoxemia, hypothermia, and associated trauma injuries. Antibiotics for patients who develop aspiration pneumonia.
• Disposition
  • Post arrest patients will require ICU admission. If no arrest, but still symptomatic, admission to floor for observation. 
  • Discharge is possible if asymptomatic and after observation in ED for at least 8 hours.

Pearls

• Although commonly performed, cervical spine immoblization is not routinely indicated unless there is a specific concern for traumatic injury.
• All drowning victims likely aspirate some amount of water, but approximately 10% will experience “dry drowning”, which is a laryngospasm preventing further aspiration.

Deep Dive

• Drowning and Submersion Injuries (emDOCs)

Rapid Review

• Background
  • Frostbite is a consequence of prolonged exposure to freezing temperatures, causing freezing and crystallization of fluids in the interstitial and cellular spaces.   
  • Typically occurs on distal extremities and areas of exposed skin
• Signs/Symptoms
  • Affected area will be cold, hard, white, and numb initially
  • After rewarming, the area will be erythematous, swollen, and painful. Full extent of injury may not be evident for several days
• Diagnosis
  • Clinical diagnosis
• Treatment
  • Rewarming in warm water (37 to 40° C). Do not attempt if refreezing is a risk.
  • Provide analgesia, wound care,and prophylaxis against tetanus. Amputation will be considered after demarcation of necrotic tissue occurs (after at least 3 weeks)
• Disposition
  • Most patients should be admitted unless only superficial cold injury (ex. frostnip). If discharged, patients should be referred to burn, plastic, or hand surgeon.

Pearls

• Rewarming should not be attempted unless patient can reliably be protected from cold environment. Refreezing injuries can be devastating
• When performing immersion rewarming, it is crucial that the water be monitored constantly to maintain temperature between  98.4 and 104 degrees F.

Deep Dive

• Frostbite (Merck Manual)

Rapid Review

• Background
  • Heat stroke is an abnormal elevation in core body temperature leading to altered mental status and organ dysfunction. It can be either nonexertional (e.g. elderly, drug abuse, prescription medication) or exertional (heavy exercise often in the young, healthy patient).
• Signs/Symptoms
  • CNS dysfunction (confusion, delirium, seizure) is a hallmark sign
  • Temperature > 40° C (104 ° F), tachycardia, tachypnea
• Diagnosis
  • Clinical diagnosis
  • Differentiated from heat exhaustion by presence of CNS dysfunction and temperature > 40° C
• Treatment
  • Aggressive cooling (cold water immersion, evaporative cooling).
  • Manage associated conditions, such as dehydration, rhabdomyolysis, and acute kidney injury
• Disposition
  • True heat stroke will require admission, possibly to the ICU if persistent hypotension or AMS. 

Pearls

• Once the patient’s core temperature has been reduced down to 100.4 degrees F, reduce cooling efforts to prevent hypothermia. 
• If the cause of the heat stroke is not obvious, consider other etiologies (sepsis, thyroid storm, serotonin syndrome, neuroleptic malignant syndrome, etc.)

Deep Dive

• Heat Stroke (emDOCs)

Rapid Review

• Background
  • Snake envenomation (bite from a poisonous snake) can cause a wide range of symptoms from mild to life-threatening. 
• Signs/Symptoms
  • Crotalid (e.g. Pit Viper) bites cause hemotoxic symptoms, such as bleeding, local swelling and bruising, as well as systemic symptoms, including vomiting, confusion and shock. 
  • Elapid (e.g. coral snake) envenomation can cause neurotoxic symptoms, such as cranial nerve weakness, paresthesias, difficulty swallowing or respiratory depression.
• Diagnosis
  • Clinical diagnosis; based on positive identification of snake and signs/symptoms of envenomation
• Treatment
  • Supportive care (remove jewelry, wrap wound loosely, immobilize at heart level). Antivenom is indicated for any moderate-severe symptoms
  • Manage hypotension, allergic reactions/anaphylaxis, and monitor for compartment syndrome
• Disposition
  • Admission required for patients requiring antivenom or those bit by elapids (needs 24 hour observation)
  • If “dry bite” or no signs of envenomation after 6-8 hours of observation, patients may be discharged with follow up in 24 hours.

Pearls

• Many prehospital treatments (ex. tourniquets, electricity, suction devices, cutting) are harmful and have not been shown to be effective.
• Identification of the snake is key for proper treatment. Pit vipers tend to have a triangular head, elliptical pupils, and heat sensing plates between the eyes and nose. Elapids have narrow heads with round pupils.

Deep Dive

• Snakebites (Merck Manual)