You are preparing to perform synchronized electrical cardioversion with a biphasic defibrillator on your unstable adult patient who is experiencing supraventricular tachycardia at 160 beats per minute on the monitor. Which of the following initial energy settings would be recommended if he was exhibiting a narrow complex, regular supraventricular tachycardia, in which his palpable carotid pulse matches the rhythm on the monitor?

Correct Answer: A

Rationale: The correct initial energy setting for synchronized electrical cardioversion in this scenario is option A: Synchronized cardioversion at 50-100 joules. This is because the patient is stable with a narrow complex, regular supraventricular tachycardia, and synchronized cardioversion is indicated for this condition. The recommended starting energy range for synchronized cardioversion in this case is typically 50-100 joules. This energy setting is appropriate for converting supraventricular tachycardia back to sinus rhythm without causing unnecessary harm to the patient. Summary of other choices: - B: Defibrillation at 100 joules: Defibrillation is not indicated for stable supraventricular tachycardia; it is used for ventricular fibrillation or pulseless ventricular tachycardia. - C: Synchronized cardioversion at 360 joules: This energy setting is too high for a stable patient with supraventricular tach

Correct Answer: C

Rationale: The correct answer is C: Upper airway protection. This is the highest priority because the patient has marked facial edema and crepitus, indicating potential airway compromise from facial fractures or soft tissue injuries. Protecting the airway is crucial to prevent further complications like respiratory distress or failure. A: Lateral c-spine x-ray - While c-spine injury should be assessed, it is not the highest priority when there is a risk of airway compromise. B: Carotid pulse assessment - While important, it is not the highest priority compared to ensuring adequate airway protection. D: Determination of associated injuries - This can be done after ensuring airway protection, as other injuries may not be immediately life-threatening.

Correct Answer: D

Rationale: Step-by-step rationale for why option D is correct: 1. During pregnancy, the hormone relaxin causes the symphysis pubis to widen to accommodate childbirth. 2. This widening of the symphysis pubis is a normal physiological change in pregnancy to facilitate the passage of the baby. 3. It is essential for the baby to pass through the birth canal during labor. 4. Therefore, a widened symphysis pubis is a normal finding in pregnancy. Summary of why other choices are incorrect: A. "Increased residual lung volume" is not normal in pregnancy as lung volume decreases due to the elevation of the diaphragm. B. "Decreased plasma volume" is not normal in pregnancy as plasma volume increases to support the growing fetus. C. "Decreased total RBC mass" is not normal in pregnancy as RBC mass increases to meet the increased oxygen demands.

Correct Answer: A

Rationale: The correct answer is A (10 min). Brain cells start to die within 4-6 minutes without oxygen. After 10 minutes, irreversible damage is likely due to lack of oxygen causing cell death. Choice B (5 min) is too short for significant irreversible damage. Choice C (2 min) is even shorter and wouldn't allow for any meaningful recovery. Choice D (20 min) is too long and underestimates the critical window for preserving brain function.

Correct Answer: C

Rationale: The correct answer is C: Traumatic brain injury. In this scenario, the patient's response to fluid resuscitation indicates that her hemodynamic instability is likely due to ongoing blood loss rather than blunt cardiac injury, inadequate resuscitation, or traumatic brain injury. The improvement in BP and HR after fluid infusion suggests that the patient is responding appropriately to volume replacement, making ongoing blood loss the most likely cause of her hemodynamic changes. Blunt cardiac injury could lead to similar symptoms, but the patient's response to fluid makes it less likely. Inadequate resuscitation would lead to persistent hypotension, which is not the case here. Traumatic brain injury typically does not cause acute hemodynamic changes like the ones observed in this case.