Which of the following is not a cause of shock?

Correct Answer: C

Rationale: The correct answer is C: Increased systemic vascular resistance. Shock is a state of inadequate tissue perfusion and oxygen delivery. Increased systemic vascular resistance would actually contribute to worsening shock by impeding blood flow to tissues. Choice A is related to oxygen delivery, which is a cause of shock. Choice B, decreased systemic vascular resistance, would lead to inadequate tissue perfusion, contributing to shock. Choice D, inadequate cardiac output, is a common cause of shock as it results in decreased blood flow to tissues.

Correct Answer: A

Rationale: The correct answer is A: Subcutaneous emphysema. This finding is indicative of air escaping into the subcutaneous tissues, causing a crackling sensation ("pop or vanish") upon palpation. The sudden-onset chest pain and dyspnea, along with jugular vein distension and cool, clammy skin, suggest a potential underlying condition such as pneumothorax or severe lung disease that leads to subcutaneous emphysema. Atelectasis (B) is incomplete expansion or collapse of the lung, typically not associated with palpable air pockets. Pitting edema (C) is caused by fluid accumulation in the tissues, not air. Ascites (D) is accumulation of fluid in the peritoneal cavity, unrelated to the findings described.

Correct Answer: A

Rationale: The correct answer is A: When a pre-existing right bundle branch block is present. ST segment elevation in patients with a right bundle branch block can be misleading as it can mimic ST elevation seen in myocardial infarction. This is due to the altered electrical conduction pathway caused by the block. Evaluating ST segment elevation in such cases may lead to a false diagnosis of infarction. Summary: - B: Evaluating ST segment elevation in a hypotensive patient is important as it can indicate the severity of the myocardial infarction. - C: In the presence of pulmonary edema, evaluating ST segment elevation is crucial to assess the extent of myocardial damage. - D: Similar to a right bundle branch block, a left bundle branch block can also lead to abnormal ST segment changes, making it necessary to evaluate for myocardial infarction.

Correct Answer: D

Rationale: The correct answer is D, "Fracture of the cribiform plate." Nasogastric intubation involves inserting a tube through the nose into the stomach. A fracture of the cribiform plate, which is part of the skull separating the nasal cavity from the brain, can lead to serious complications such as penetrating injury to the brain or leakage of cerebrospinal fluid. This can result in infections or other severe issues. A: "Gastric perforation" is a possible complication of nasogastric intubation but not a contraindication. B: "Diaphragmatic rupture" is not a direct contraindication to nasogastric intubation. C: "Open depressed skull fracture" is a serious condition but not a direct contraindication to nasogastric intubation.

Correct Answer: A

Rationale: Certainly! The correct answer is A because cerebral contusion, which is a bruising of the brain tissue, can indeed coalesce to form an intracerebral hematoma, which is a collection of blood within the brain tissue. This process occurs due to the disruption of blood vessels during the contusion. Choice B is incorrect as epidural hematomas are typically seen in the temporal region, not the frontal region. Choice C is incorrect because subdural hematomas are usually caused by injury to the bridging veins rather than the middle meningeal artery. Choice D is incorrect as subdural hematomas typically have a crescent shape on CT scans, not a lenticular shape.