Management of Ammonia Exposure

After an ammonia leak last night in Rosemount MN, one person died at the scene and several people were treated at our trauma center. Ammonia exposure is not very common, but can cause serious injury or death. This blog will review the facts about ammonia exposure and provide basic management tips for EMS and hospital personnel.

Nearly everybody who has worked with household cleaning products is familiar with the odor of ammonia. The gas is colorless with a potent, irritating smell. Ammonia gas is added to water to make cleaning solutions. Farmers use anhydrous ammonia to make fertilizer, which is a very pure form that is drawn to moisture. Ammonia is usually transported under pressure in steel tanker trucks in the form of a clear liquid.

From the medical standpoint, ammonia causes problems because it combines with water to form ammonium hydroxide, a strong alkali (base). When humans are exposed, an alkaline solution forms on any moist areas such as skin, eyes and mucus membranes. Inhaling the gas causes deeper exposure and burns in the respiratory tract. Higher concentrations of gas cause greater injury, with eye damage occurring very commonly that can lead to blindness.

Prehospital management:

• Protect yourself! A HAZMAT Hot Zone should be established with all personnel entering the zone properly protected with SCBA breathing apparatus and chemical protective suits.
• If victims can walk, lead them out of the Hot Zone. If not, drag them.
• Patients with exposure to gas only do not pose a risk to EMS personnel. Decontamination is not necessary, and they can be moved to the Support Zone.
• Pay attention to ABC as you would with any trauma patient.
• All other patients require decontamination in the Decontamination Zone as follows:
• 1. Flush exposed skin and hair for at least 5 minutes. Use warm water if possible to avoid hypothermia. Wash with soap and water if possible.
• 2. Irrigate eyes for at least 15 minutes. Remove contact lenses if possible.
• 3. Double-bag contaminated clothing and personal belongings.
• 4. For ingestions, do not induce vomiting, attempt to neutralize, or give activated charcoal. Conscious victims should be encouraged to swallow 4-8 oz of water or milk. Prepare the ambulance for possible toxic emesis prior to transport.

Transport patients to the nearest Burn Center or burn-capable hospital.

The receiving Emergency Department should prepare a separate area to receive any patients with residual contamination for additional decontam. Decontamination times and methods are similar to prehospital. Patients exposed only to ammonia gas do not need a separate area.

For additional information, click here to download a detailed document from the Agency for Toxic Substances & Disease Registry, a part of DHHS.

How to Rapidly Reverse Coumadin in Head Injured Patients

A growing number of adults, usually elderly, are taking Coumadin (warfarin) to manage chronic medical conditions or deep venous thrombosis. While warfarin is a very useful drug for these problems, it is notoriously difficult to maintain tight control of INR. If an individual on warfarin is involved in a fall or vehicular crash, bleeding complications can become life-threatening. A recent Journal of Trauma article shows that mortality more than doubles in elderly patient who are admitted awake after just falling from standing.

The key is to rapidly reverse an elevated INR. Vitamin K can be used to increase biological activity of several clotting factors, but this occurs over several hours. Plasma is also used, but there are several considerations. Many hospitals have only frozen plasma, and there may be a delay of 30 to 45 minutes to thaw it. Multiple units may need to be transfused in order to normalize higher INRs, which may cause volume overload in elderly patients with cardiovascular disease.

More recently, activated Factor VII (NovoSeven) has been used to aid rapid reversal of the INR. NovoSeven is FDA approved for only the following uses:

• Bleeding or surgery in hemophiliacs
• Bleeding or surgery in congenital Factor VII deficiency

Use of NovoSeven for rapid reversal of warfarin is an off-label use, and physicians must weigh the risks and benefits prior to use. It is also very costly, about $7000 per vial.

To download a printable copy of our protocol, click here.

PROTOCOL – PATIENTS ON WARFARIN WITH HEAD INJURY AND ABNORMAL CT SCAN

Check INR. Goal INR is 1.2-1.4

If > 1.4

• Give Vitamin K 10 mg IV
• Transfuse thawed plasma 15ml/kg (4-6 units)
• Consider NovoSeven
  Weight <>= 100kg – give 2mg IV

Repeat INR at 2hrs, 4hrs, 12hrs and 24 hrs after NovoSeven administration.

If INR increases to > 1.4, repeat plasma transfusion as needed.

Reference: J Trauma. 2009 Jun;66(6):1518-22; discussion 1523-4.

NOTE: This guideline is based on protocols in use at the Regions Hospital Level I Adult and Pediatric Trauma Centers. As with any potent drugs or procedures, undesired side-effects may occur. The individual physician prescribing these medications or procedures is solely responsible for the safety of his or her individual patient.