Blast Injuries Workup

Updated: Aug 06, 2021
  • Author: Andre Pennardt, MD, FACEP, FAAEM, FAWM; Chief Editor: Trevor John Mills, MD, MPH  more...
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Laboratory Studies

Judicious use of the laboratory is essential for accurate diagnosis in the mass-casualty situation. Do not overwhelm the laboratory with screening or protocol laboratory tests of little clinical benefit.

Most patients injured by significant explosions should have a screening urinalysis.

If the explosion occurred in an enclosed space or was accompanied by fire, test carboxyhemoglobin (HbCO) and electrolytes to assess acid/base status.

Pulse oximetry readings may be misleading in cases of CO poisoning. When in doubt, apply 100% oxygen by tight-fitting face mask until CO levels can be measured.

Exposure to cyanide (CN), a product of incomplete combustion of plastics, is difficult to measure directly. CN exposure often accompanies CO poisoning. Consider CN poisoning in patients exposed to combustion in an enclosed space who have an anion gap metabolic acidosis (see the Anion Gap calculator). Treatment for CN poisoning should be started for significantly ill patients while awaiting confirmatory test results. Sodium thiosulfate or hydroxocobalamin are safe and appropriate empiric therapies.

Victims of major trauma should have baseline hemoglobin determinations, crossmatching for potential blood transfusion, and screening for DIC. If significant crush injury, compartment syndrome, or severe burns have occurred, emergency physicians should be attentive to the possibility of rhabdomyolysis with resulting hyperkalemia and myoglobinuric renal failure. Useful tests for DIC include the following:

  • Protime
  • Activated partial thromboplastin time (aPTT)
  • Thrombin time
  • Fibrinogen
  • Fibrin split products
  • D-dimer levels
  • Serial CBC determinations, to include platelet counts

Patients with burns from military white phosphorous (WP) munitions are at risk for hypocalcemia and hyperphosphatemia; follow serial levels of these ions. WP is a metal that ignites on contact with air, creating intense heat and releasing phosphorous pentoxide, a severe pulmonary irritant. WP is a widely used component of military munitions, including hand grenades.


Imaging Studies

Perform chest radiography in patients who have been exposed to high overpressure and are therefore at high risk for primary blast injury. This group of patients may include all patients with TM rupture from blast injury. Chest radiographs should be performed on all patients who exhibit respiratory symptoms, have abnormal findings on auscultation, or have visible external signs of thoracic trauma.

If significant abdominal pain is present, consider an immediate abdominal radiographic series (flat and upright films) or abdominal CT to detect pneumoperitoneum from enteric rupture. The focused abdominal sonography for trauma (FAST) examination is a potentially useful tool for rapidly screening patients, especially in the setting of multiple seriously injured victims. A positive FAST examination in an unstable patient is an indication for surgical exploration of the abdomen in the operating room. In stable patients, a positive FAST examination can facilitate prioritization for CT imaging. A negative FAST examination is unreliable in the setting of penetrating trauma to the abdomen, flank, buttocks, or back, and it should be followed up with CT examination of the abdomen and pelvis. Ultrasonography can rapidly rule out the presence of pericardial tamponade.

No practical, sensitive test exists for intestinal hematoma. The diagnosis is often missed even when performing the best available test — abdominal CT. Because intestinal hematoma can take 12-36 hours to develop, symptoms such as increased pain or vomiting should determine decisions about testing.


Other Tests

If there is any question of radiation or chemical contamination, arrange to test and decontaminate patients and equipment.  Most fire departments' hazardous materials teams have the training and equipment to perform this task.  Notify the hospital's radiation safety officer (often the chief technician for the radiology department's nuclear medicine section) for assistance screening victims for radiation contamination. Contact hospital public relations to work with the press.