Emergency Medical Services (EMS) Agency

CASE OF THE MONTH – MAY 2019

 

Case Presentation:

 

Paramedics respond to a house fire with persons entrapped.  A 61 year-old male is unresponsive after extrication from the burning building.  He has blistering burns covering his anterior torso (chest and abdomen), the right side of his neck, and his right arm.  Superficial burns to the patient’s right face and proximal right leg are also present.  Paramedics note dilated pupils, singed nasal hairs and soot in his oropharynx, indicating airway involvement of the burn.  His blood pressure is 89/50 mmHg, heart rate 125, respiratory rate 6 with shallow ventilations, oxygen saturation is 90% on room air.  His skin is flushed and diaphoretic.

Multiple provider impressions (PI) apply, highlighting the complexity and the critical nature of the case.  The patient has severe burns with respiratory failure due to likely smoke inhalation injury and is also exhibiting signs of shock with hypotension and altered mental status.   Burn may be the best primary PI in this case, since it captures the major insult.  However, respiratory Arrest/Failure, Smoke Inhalation, and Shock all apply.  ALOC is nonspecific and should not be included as a PI in this case; instead it is a physical exam finding supporting the other PIs.

 

The first step has already been taken, to remove the patient from the hazardous environment.  Following this, resuscitation should be initiated with high-flow oxygen.  Early advanced airway placement should be strongly considered, given the anticipated airway swelling from the inhalation injury.

 

Burns cause large amounts of fluid losses.  Fluid resuscitation should be initiated in the field with Normal Saline 1L IV/IO rapid infusion.   If an IV cannot be rapidly established, an IO placed in the non-burned extremity is appropriate for this patient in extremis.  Base contact is not required and establishing vascular access should not be delayed.   Burn patients with >20% total body surface area (TBSA) involvement typically require a minimum of 4 ml x kg body weight x % TBSA during the acute phase (a minimum 6L in an average adult).   Half the volume is given in the first 8 hours and the balance in the next 16 hours of care.

 

These patients also lose heat due to damage to the skin barrier.  The patient should be kept warm with blankets and temperature control in the ambulance, since hypothermia can occur rapidly and contribute to hemodynamic compromise.

Paramedics initiate assisted ventilation with high-flow oxygen via bag-mask and prepare for advanced airway placement.  They establish an IO at the left proximal tibia and begin Normal Saline 1L rapid infusion.  They cover the patient with blankets.

This patient has evidence of significant smoke inhalation from a house fire.  The patient is at risk for carbon monoxide (CO) exposure and cyanide toxicity.

 

CO is formed as a by-product of burning organic compounds.  The majority of CO exposure fatalities occur from fires.  CO binds to hemoglobin in red blood cells forming carboxyhemoglobin.  The formation of carboxyhemoglobin prevents oxygen from binding to hemoglobin, leading to hypoxia by disrupting normal oxygen delivery to cells.  This causes a “functional anemia” and results in oxygen not being delivered to cells appropriately for metabolism.

 

Smoke inhalation during house or industrial fires is also the major source of cyanide poisoning in the United States.  The presence of soot in the mouth, altered mental status and hypotension all raise concern for cyanide toxicity in this patient.  Cyanide blocks the ability of the body to use oxygen for metabolism at the cellular level, even in the presence of adequate oxygenation.  Cellular metabolism becomes anaerobic, producing lactic acid.  The brain and heart are the most profoundly affected, because these organs have the highest oxygen requirements.  Acute neurologic symptoms include mild symptoms like headache and vertigo, progressing in severity to seizures and coma.  Cardiopulmonary symptoms include shortness of breath, chest pain, and apnea.  Patients may present initially with bradycardia and hypertension, but rapidly become hypotensive with reflex tachycardia.  Cardiac dysrhythmias may be followed by cardiac arrest.

High-flow oxygen is the field treatment for carbon monoxide poisoning.  Although oxygen theoretically cannot treat cyanide toxicity, since cyanide blocks cellular use of oxygen, administration of oxygen has proven effective in some poisonings and it is not harmful in this situation. Therefore, high-flow oxygen should be administered.

 

Hydroxocobalamin is the specific antidote for cyanide toxicity.  This medication is not in Los Angeles County paramedic scope of practice, but may be administered in the emergency department (ED).

Adult patients with 2nd or 3rd degree burns involving ≥20% TBSA should be transported to the closest Trauma Center, unless the burn center is closer.  For children ≤14 years this percentage is ≥10% TBSA. Though not applicable to this patient, if a patient has a traumatic injury associated with the burn which requires trauma center care, then the patient should be transported to the closest Trauma Center regardless of the extent of the burns.

 

In order to determine the TBSA involved in this patient,  one can use the Wallace rule of nines as depicted in the diagram below.  In addition, the “rule of palm” allows one to estimate smaller areas (i.e., the palm of the person burned is approximately 1% of the body).  This patient has involvement of the anterior torso (18%), right neck (1%), and right arm (9%), making up approximately 28% TBSA.

burn2

Figure Source:  WHO Publication.  Surgical Care at the District Hospital.  2003; PTCM–35

https://www.who.int/surgery/publications/scdh_manual/en/

 

In children estimates of TBSA are more difficult to calculate since they change with age.  In general, the head is a relatively larger percentage of the TBSA, making up as much as 10% per side (20% total) in infants.  For pediatric patients, initiate fluid resuscitation 20mL/kg based on weight.

burn1

Paramedics intubate the patient to secure the airway and initiate transport to the closest Trauma Center.  En route, the patient becomes increasingly bradycardic and his carotid pulse is no longer palpable.  The following rhythm is visualized on the monitor.

burn4

This patient has a non-traumatic cardiac arrest, which should be managed per TP-1210, Cardiac Arrest.   The rhythm strip shows slow pulseless electrical activity.  Treatment should be directed at the likely underlying cause(s).  In this case, profound shock from fluid losses is one likely contributing cause that can be treated in the field.  In addition, patients with burns are at risk to develop hyperkalemia, because of cell lysis and tissue necrosis.  Therefore, it is reasonable to consider treating the patient with additional Normal Saline, Calcium Chloride, and Sodium Bicarbonate for suspected hyperkalemia.  Hypoxia due to cyanide or CO toxicity are other

Paramedics initiate CPR.  They establish additional vascular access in the left upper extremity to continue aggressive fluid resuscitation suspecting profound shock as the cause of the patient’s cardiac arrest.  After administration of epinephrine 1mg IO and 2 minutes of CPR, return of spontaneous circulation (ROSC) is achieved.

On ED arrival the patient remained unresponsive, intubated.  Initial blood pressure was 149/100 and heart rate 117 after epinephrine in the field.  However, the patient quickly became hypotensive again requiring vasopressor support.  His laboratory values included a pH of 6.9, carboxyhemoglobin (HbCO) of 21%, potassium of 7, and a lactate of 15.  He was treated with additional fluids for a total of 6 liters, calcium chloride and sodium bicarbonate for hyperkalemia, and hydroxocobalamin for presumed cyanide toxicity.   After initial stabilization in the ED at the Trauma Center, he was transferred to the burn center with critical care transport for further management.

 

 

Learning Points

  • Management of burns is per TP-1220, Burns.  Management priorities for patients with severe burns include administration of high-flow oxygen, fluid resuscitation, and maintaining warmth. For critical patients, additional treatment protocols may apply for the management of smoke inhalation (TP-1236, Inhalation Injury) with or without respiratory failure (TP-1237, Respiratory Distress).
  • For patients with evidence of airway burns, early advanced airway placement is indicated, because of the risk of airway swelling and obstruction.
  • Victims of structure fires are at risk for CO exposure and cyanide toxicity.  For any patient exhibiting neurologic and/or cardiopulmonary symptoms, presumptive treatment should be administered with high-flow oxygen.
  • Critical burn patients are at risk for cardiac arrest due to hypovolemia, hyperkalemia, and/or complications from CO and cyanide toxicity including functional anemia and dysrhythmias.  These patients should be managed per TP-1210, Cardiac Arrest.
  • The total body surface area (TBSA) involved in the burn can be estimated with the Wallace rule of nines and/or the “rule of palm”- areas of 2nd and 3rd degree burns should be included in the estimate.
  • Adult patients with 2nd and 3rd degree burns ≥20% TBSA and pediatric patients with  ≥10% TBSA should be transported to the closest Trauma Center (or Burn Center if it is closer) within 30 minutes.
  • Burns are very painful.  For alert patients with adequate perfusion, analgesics (morphine or fentanyl) should be administered.

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