You are called to assist a 20-year-old male for a severe headache. On-scene, you learn the patient was involved in an accident that caused a potential closed head injury. However, at the time of the accident, the patient refused EMS care, stating he felt fine. Today, he is experiencing headache, confusion, and visual disturbances. Which of the following injuries is most likely to cause this type presentation?

Correct Answer: C

Rationale: The correct answer is C: Subdural hematoma. A subdural hematoma is a collection of blood between the dura mater and arachnoid mater layers of the meninges. This type of injury typically occurs due to acceleration-deceleration forces causing tearing of bridging veins, common in closed head injuries. The symptoms described (headache, confusion, visual disturbances) are consistent with the presentation of a subdural hematoma. Other choices are less likely: A) Coup-contra-coup injury involves impact forces causing brain injury at the site of impact and opposite side, typically seen in motor vehicle accidents. B) Diffuse axonal injury is caused by shearing forces leading to widespread damage throughout the brain, often resulting in a comatose state. D) Epidural hematoma is a collection of blood between the dura mater and the skull, usually due to arterial bleeding, and is more commonly associated with a lucid interval followed by rapid deterioration, but

Correct Answer: C

Rationale: Rationale for Answer C being FALSE: A negative Kleihauer-Betke test does not exclude Rh-isoimmunization. The test measures the amount of fetal red blood cells in the maternal circulation, but may not always detect small amounts of fetal-maternal hemorrhage. Rh-isoimmunization can still occur even if the Kleihauer-Betke test is negative. Summary of other choices: A: True - Rh-isoimmunization can occur in both blunt or penetrating abdominal trauma. B: True - Even minor degrees of fetomaternal hemorrhage can lead to Rh-isoimmunization. D: False - Rh-isoimmunization can be a problem in both Rh-positive and Rh-negative pregnant trauma patients.

Correct Answer: D

Rationale: The correct answer is D because the statement is false. Children have a smaller blood volume than adults, so the absolute volume of blood loss required to produce shock in children is lower than in adults. A: Vital signs are age-related as children have different normal ranges compared to adults. B: Children actually have lesser physiologic reserves than adults. C: Tachycardia is a common response to hypovolemia, not hypervolemia.

Correct Answer: A

Rationale: The correct answer is A: "Permissive hypotension and early plasma infusion" for balanced resuscitation. Permissive hypotension helps prevent exacerbating bleeding by maintaining lower blood pressures. Early plasma infusion provides essential clotting factors for coagulopathy correction. Choice B is incorrect as equal crystalloid and colloid amounts are not recommended due to colloid-related complications. Choice C is incorrect as balanced resuscitation focuses on fluid and blood product administration, not breathing management. Choice D is incorrect as maintaining a normal acid-base balance is essential but not the sole focus of balanced resuscitation.

Correct Answer: D

Rationale: The correct answer is D. X-ray of the chest and pelvis are important adjuncts in his assessment. This patient's mechanism of injury is indicative of high energy trauma. X-ray of the chest can help identify potential thoracic injuries such as rib fractures or pneumothorax. Pelvic x-ray is crucial to assess for pelvic fractures, which can lead to significant blood loss and hypotension. This patient's hypotension is more likely due to hemorrhagic shock from his open tibial fractures rather than spinal cord injury. Pelvic injury cannot be ruled out solely based on the mechanism of injury as pelvic fractures are common in falls from height. Blood loss from the lower limb alone is not the most likely cause of hypotension in this case.