7-24
respirations, shock, or exposure to chemical agent such as cyanide. Persistent SPO2 75-95% on room air
indicates mild lung injury.
Using Advanced Tools:
Stool Guaiac: Gross hematochezia (bowel injury), guaiac-positive stool (occult penetrating, blunt, or blast
trauma). Ophthalmoscope: Penetrating anterior-eye trauma, lack of red reflex (indicates posterior-eye
trauma). Otoscope: Ruptured TM.
Assessment:
Differential Diagnosis
Rapid unconsciousness - penetrating or blunt brain or cardiac trauma, vasovagal syncope, cerebral or cardiac
AGE, chemical nerve-agent or cyanide inhalation.
Airway compromise - altered mental status, penetrating or blunt face or neck trauma, inhalation injury, massive
hemoptysis, foreign-body aspiration.
Ventilatory insufficiency - pulmonary contusion, pneumothorax (all types), rib fractures, bronchopleural fistula,
chemical-agent or biological-toxin exposure.
Shock - external or internal hemorrhage, tension pneumothorax, hypoxia from pulmonary injury, GI bleed
(more often lower), coronary AGE.
Focal neurological deficits - head injury, spinal injury, peripheral nerve injury, cerebral or spinal AGE.
Plan:
Treatment: Evaluate for necessity of tetanus immunization booster.
- Shock: Resuscitate as per Shock chapter. Bolus with one quarter the usual amount (crystalloid or
hetastarch) and reevaluate to avoid exacerbating lung or brain injury. Repeat boluses as necessary to
restore mental status, as the endpoint of resuscitation. - AGE: Primary: Evacuate URGENT to hyperbaric oxygen chamber. Administer 100% oxygen.
Alternate: Place casualty in coma position with left side down (halfway between left-lateral decubitus and
prone) and head at same level as heart (Figure 1-1). Perform in-water recompression as a last resort
in divers exposed to blast. - Massive hemoptysis compromising airway: Selective intubation of mainstem bronchus on least injured
side. Use lumen of tube to facilitate gas exchange in and out of lung with lighter bleeding. Use cuff to
prevent blood from side of heavier bleeding crossing into mainstem bronchus of better
lung. See algorithm (see Figure 7-5) below. Numbers in boxes of algorithm indicate order of preference
of interventions listed. - Pneumothorax, tension pneumothorax, hemothorax, pulmonary contusion: Consult appropriate
section of this book. Do not use morphine if bradycardic. Predict need for positive-pressure ventilation
(PPV) or positive end-expiratory pressure (PEEP) using chart below. PEEP will not be available in
the field, but PPV can be done with a mouth-to-mask or bag-valve-mask/tube with slower and less forceful
deliveries. AGE is most common cause of death in immediate survivors and often occurs when PPV
is initiated. Contusion usually requires temporary supplemental oxygen. Pharyngeal petechiae (but not
TM rupture) predict higher likelihood of pulmonary contusion.
Prediction of Respiratory Problems
Insignificant pulmonary injury may be defined as no dyspnea with exertion after 1 hour of rest post-blast.
Significant pulmonary blast injuries may be classified based on pulse oximetry. This may predict likelihood
of complications, and requirement for PPV and PEEP.
Mild: SPO2 > 75% on room air, unlikely to need PPV, normal PEEP if PPV initiated, pneumothoraces
occur, bronchopleural fistulae rare
Moderate: SPO2 > 90% on 100% oxygen, likely to need conventional PPV, PEEP of 5-10 cm H 2 O usually
needed, pneumothoraces common
Severe: SPO2 < 90% on 100% oxygen, likely to need unconventional PPV, PEEP > 10 cm H 2 O usually
needed, pneumothoraces almost universal, bronchopleural fistulae common - GI bleeding, GI tract rupture: See Abdominal Trauma section on CD-ROM for additional guidance.