You are called to a scene for a 48-year-old male presenting with sudden onset of severe shortness of breath, tachypnea, and a rapid pulse. He is alert and oriented, and physical exam reveals a swollen right calf with tenderness. Which condition is most likely causing his symptoms?

Correct Answer: B

Rationale: The correct answer is B: Pulmonary embolism. Given the sudden onset of severe shortness of breath, tachypnea, rapid pulse, and swollen right calf with tenderness, the most likely diagnosis is a pulmonary embolism. A pulmonary embolism occurs when a blood clot travels to the lungs, blocking blood flow. This leads to symptoms of shortness of breath, tachypnea, and rapid pulse. The swollen right calf with tenderness suggests a possible deep vein thrombosis, which can lead to a pulmonary embolism. The other choices are less likely because they do not fully encompass the patient's presentation and physical exam findings. A myocardial infarction typically presents with chest pain, not solely shortness of breath and calf swelling. Tension pneumothorax presents with respiratory distress and decreased breath sounds, not calf swelling. Severe asthma attack may cause shortness of breath but is less likely to present with a swollen calf.

Correct Answer: D

Rationale: The correct answer is D: 80 joules. Initially, you should use a higher energy setting to ensure successful capture in a conscious patient. Starting at a higher energy level increases the chances of achieving capture without causing harm. Option A is incorrect because using the highest setting may lead to unnecessary discomfort or injury. Option B is incorrect as using the minimum setting may not provide enough energy for capture. Option C is incorrect as 50 joules may be insufficient for successful pacing in a conscious patient. Starting at 80 joules is a prudent choice to maximize the chance of successful capture while minimizing potential harm.

Correct Answer: B

Rationale: The correct answer is B: O-negative packed red blood cells. Packed red blood cells are the most appropriate choice for a patient in hypovolemic shock as they help increase the oxygen-carrying capacity of the blood. In this scenario, the patient's hemorrhage is controlled, indicating a need for red blood cells rather than whole blood. O-negative blood is universally compatible, reducing the risk of transfusion reactions. Plasma-containing products like whole blood (choice A) may not be necessary if there is no active bleeding or coagulopathy present. O-positive packed red blood cells (choice C) may not be compatible with the patient's blood type, risking transfusion reactions. O-positive whole blood without plasma (choice D) may not provide adequate oxygen-carrying capacity needed in hypovolemic shock.

Correct Answer: A

Rationale: The correct answer is A. To determine death in the pre-hospital environment, EMS professionals must confirm the absence of electrical activity in the heart. Asystole on an EKG tracing indicates no heartbeat, which is a critical criterion for declaring death. Other choices are incorrect because they do not definitively confirm death. Choice B, apnea with a gag reflex, does not necessarily indicate death as the gag reflex can persist after cessation of breathing. Choice C, lividity and cold/clammy skin, are signs of postmortem changes but do not conclusively establish death. Choice D, pinpoint pupils and decreased muscle tone, are indicators of neurological dysfunction but not definitive signs of death.

Correct Answer: D

Rationale: The correct answer is D: Presence of deep tendon reflexes. In hypotension due to spinal cord injury, deep tendon reflexes are typically absent below the level of injury. This is known as spinal shock. The presence of deep tendon reflexes suggests intact spinal cord function and points towards a cause of hypotension other than spinal cord injury. Prispism (A) is not a physical finding associated with hypotension or spinal cord injury. Bradycardia (B) can be a common finding in spinal cord injury due to autonomic dysregulation. Diaphragmatic breathing (C) is also not directly related to hypotension or spinal cord injury.