Emergency Medical Services (EMS) Agency

Radiation Exposure — September 2019

Case presentation

Paramedics respond to a two-vehicle traffic collision (TC) on a local freeway.  A pick-up truck and a nuclear medicine diagnostic imaging van have collided.  The imaging van is over-turned and the pick-up truck has sustained severe damage.

The driver of the imaging van (Patient #1) is a 38-year-old man that is ambulatory at the scene with minor injuries.  He is carrying a locked box which he states contains the medical isotope Technetium-99m (Tc99m), a gamma emitter, which he has secured from the vehicle after the accident.  Paramedics ask if the imaging van contains any other radiologic material.  The driver responds, “there may be some equipment that has residual material.”

The driver of the pick-up truck (Patient #2), a 42-year-old man, was ejected from the vehicle and found underneath the imaging van.  He is altered with signs of blunt trauma to the chest and abdomen, trauma to the face, and obvious deformities to his right arm and leg.  His vital signs are BP 70/54 HR 145 RR 20 SpO2 90%.

The provider impressions for both patients are Traumatic Injury (TRMA) and each patient should be treated in accordance with TP-1244, Traumatic Injury.  There is also concern for hazardous material exposure given possible radiologic material at the scene following the collision.  Therefore, this case should also be managed using TP-1240, HAZMAT.

Patient #2 has sustained multisystem trauma with poor perfusion; he is hypotensive with an altered mental status.  He should be assessed and treated without delay for his life-threatening condition in conjunction with any decontamination that may be applicable.  EMS personnel should evaluate for any active hemorrhage or extremity wounds that would require a tourniquet, determine if a tension pneumothorax is suspected so that treatment can be administered, and volume resuscitate the patient with Normal Saline 250mL IV/IO rapid infusion.  The patient should be transported to the nearest Trauma Center.  The risk to EMS personnel from exposure to a patient that is externally contaminated with radiation is minimal.  If there is concern for radiologic contamination on this patient, all outer clothing should be removed and contained before transport.

Patient# 1 is also a trauma patient.  A full assessment should be performed to identify any injuries.

Appropriate radiation detection devices should be used to determine if radiation contamination is present at the scene.  Departmental HAZMAT protocols should be initiated.  The Department of Public Health (DPH), Radiation Management should be contacted for scene assessment as per HAZMAT protocols.

Full trauma assessments are performed on both patients.  Patient # 1 has no injuries noted.  Immediate resuscitation is started on Patient # 2.  Given the potential for radiation at the scene, all treatment personnel don their personal dosimeters.

Given the possibility of a radiological contaminated imaging van, Patient # 2 is moved away from the vehicle, his clothing is removed as part of his trauma assessment and for decontamination purposes.  The potentially contaminated clothing is contained while awaiting HAZMAT arrival.  Patient #2 is quickly transported to the Trauma Center.

HAZMAT arrives and conducts a radiation survey of the vehicles and notes elevated radiation readings near the imaging van approximately 3’ from the van’s outer under carriage.  Additional surveys are performed to localize the source of radiation.

Time, Distance, and Shielding are the key principles to reduce potential radiation exposure.

EMS personnel are advised to:

  1. Minimize their time near potential sources of exposure.
  2. Maximize their distance from potential sources of exposure.
  3. Also, as is possible, use vehicles or walls as shielding from potential sources of exposure.

In this case, EMS personnel recognized the over-turned imaging van as a potential source for radiation exposure and appropriately moved Patient #2, limiting the time both they and the patient were potentially exposed and providing distance from the potential source.  In addition, they shielded the patient and themselves by moving the patient behind the transport ambulance for assessment and immediate treatment measures.  All personnel and others at the scene should be instructed to remain a safe distance away from a potential source until HAZMAT can determine the safety of the scene.

Radiation exposure occurs when all or part of the body absorbs penetrating ionizing radiation from an external radiation source.  An individual that is only exposed to an external source of radiation is NOT radioactive or contaminated and may be approached without risk.  An example of this would be a person that has had an x-ray or CT scan.  There is no risk to others after the patient has been exposed.

Radioactive contamination is when unwanted radioactive material is deposited on the surfaces of structures, areas, objects or people.  The contaminating radioactive material may further expose others if in close proximity.

External contamination may follow a spillage of radioactive isotopes, as may have occurred in this scenario.  External contamination may also be due to a radiologic material release (RMR), or detonation of a radioactive dispersal device (RDD) –also known as a “dirty bomb”.  In a dirty bomb, conventional explosives are mixed with radioactive material.  When the dirty bomb explodes, it disperses the radioactive material. The explosive dust laced with radioactive material settles on the victims and their surroundings, leading to potential radiation exposure.  This external contamination exposes each victim to radiation, and will continue to expose them until it is removed.  External contamination can further contaminate an EMS ambulance unit and the Emergency Department, if the contaminated source is not promptly removed.  Removal can be quickly accomplished through decontamination by removing the patient’s clothing.  This simple action, removes 80% to 90% of external contamination minimizing the threat to first responders.

In RMR/RDD scenarios, inhaling or ingesting (licking the lips) dispersed radiologic dust can convert an external contamination into an internal contamination.  Internal contamination is when radiologic material enters the body through an open wound, ingestion or inhalation.

For EMS personnel, exposure to victims with internal radiation contamination poses low-to-no risk.  Exposure to victims with external radiation contamination poses low-to-moderate risk that can be further mitigated by removing the outer layers of clothing and then following the principles of time, distance, and shielding regarding exposure from radiation sources.

HAZMAT completes their scene assessment and locates the source of detected radiation:  a bag of medical waste used for a recent scan.  Once the medical waste item is removed from the vehicle, a full radiation survey of the van is conducted, and no other radiation elevations are observed.  Therefore, HAZMAT concludes that no radioactive isotope ‘spillage’ has occurred and the scene is safe from a radiologic contamination standpoint.

Patient #1 is treated and released at the scene as per Ref. No. 834.

Patient #2 is transported to the Trauma Center.  He has sustained a traumatic subdural hematoma, facial fractures, liver and splenic lacerations and a fractured humerus and femur.  He is resuscitated in the Emergency Department with blood products and taken to the operating room for surgical management.  He is treated in the ICU for several days and discharged after several weeks in the hospital to a rehabilitation facility.  He was exposed to minimal amounts of radiation due to the collision and suffered no adverse sequelae from exposure.  His lymphocyte count was monitored during his admission with no change to suggest a clinically significant radiologic exposure.

 

Learning Points:

  • Appropriate HAZMAT protocols should be followed for any suspected radiologic exposure cases.  Departmental HAZMAT and/or the Department of Public Health (DPH), Radiation Management Team should be contacted to determine scene safety.
  • Do not delay care for patients with life threatening conditions when radiologic exposure or contamination is being considered.
  • Removal of clothing can accomplish decontamination of 80% – 90% of radiologic material during a radiation contamination event.
  • Time, distance and shielding are the key principles to reduce the risk of radiologic exposure to EMS personnel.

References

1. Radiation Emergency Medical Management.  Guidance on Diagnosis and Treatment for Healthcare Providers.

https://www.remm.nlm.gov/index.html Accessed 8/28/2019

2. Emergency Response Guidebook 2016.  Department of Transportation.  http://icc.pub/downloads/erg/2016-erg.pdf

3. Radiation Emergencies:  Information for Professionals. https://www.cdc.gov/nceh/radiation/emergencies/clinicians.htm

 

Author:  Dr. Millicent Wilson, MD; Dr. Denise Whitfield, MD, MBA