While evaluating the twelve-lead electrocardiogram tracing of your 66-year-old cardiac history patient for the possibility of an acute myocardial infarction, you note the presence of deep symmetrically inverted T waves. Which of the following is most likely the cause of this abnormal finding?

Correct Answer: B

Rationale: The correct answer is B: Ischemia. Deep symmetrically inverted T waves on an ECG are indicative of myocardial ischemia, where the heart muscle is not receiving enough oxygen-rich blood. This can lead to reversible changes in the ECG tracing. Ischemia is a common cause of T wave changes in patients with a cardiac history, suggesting ongoing heart strain. Necrosis (choice A) would typically present with pathological Q waves on ECG, not T wave inversions. Hyperkalemia (choice C) may cause peaked T waves, not symmetrically inverted ones. Hypokalemia (choice D) can lead to flattened or U-shaped T waves, not deep symmetric inversions.

Correct Answer: A

Rationale: The correct answer is A: "GCS" (Glasgow Coma Scale). During the primary survey in trauma, assessing the patient's level of consciousness using GCS is crucial to identify any potential brain injury. The patient's airway, breathing, and circulation are already assessed and stable based on the given information. GCS helps determine the severity of head injury and guides further management. B: Cervical spine x-ray is not indicated during the primary survey unless there is suspicion of cervical spine injury based on mechanism of injury or physical exam findings. C: TT-administration (tetanus toxoid) is important but is not a priority during the primary survey. It can be administered later in the secondary survey. D: Blood alcohol level is not necessary during the primary survey for acute trauma management. It can be considered in the secondary survey for further evaluation.

Correct Answer: A

Rationale: The correct answer is A because cervical spine injury can initially present as a neurologic deficit after neck movement due to spinal cord compression or injury. This is due to the delicate nature of the spinal cord in the cervical region. Choices B and C are incorrect as normal range of motion and physical examination maneuvers may not rule out cervical spine injury. Choice D is incorrect as a crosstable lateral x-ray may miss certain types of cervical spine injuries, such as ligamentous or soft tissue damage.

Correct Answer: C

Rationale: The correct answer is C: DPL (Diagnostic Peritoneal Lavage). DPL is the most specific test for evaluating injuries of solid abdominal organs like the liver or spleen. It involves inserting a catheter into the peritoneal cavity to detect the presence of blood or other fluids, indicating internal bleeding. Abdominal x-ray (A) is not specific for solid organ injuries. Abdominal ultrasound (B) is more commonly used for detecting fluid collections or organ abnormalities but may not be as sensitive as DPL for detecting solid organ injuries. Frequent abdominal examination (D) is important for ongoing monitoring but does not provide the same level of specificity as DPL in diagnosing solid organ injuries.

Correct Answer: D

Rationale: The correct answer is D: "Ensuring adequate oxygenation and ventilation" should be performed first in any patient with potential multiple closed extremity fractures. This is because prioritizing oxygenation and ventilation is crucial to prevent hypoxia and respiratory compromise, which can be life-threatening. Once the patient's oxygenation and ventilation are stabilized, further assessments and interventions can be performed. A: "A thorough assessment of four limb perfusion" may be important but ensuring adequate oxygenation and ventilation takes precedence. B: "Maneuvers to prevent necrosis of the skin" is not the immediate priority over ensuring oxygenation and ventilation. C: "Extremity compartment syndrome release" is a critical intervention but should be performed after ensuring adequate oxygenation and ventilation.