Correct Answer: D

Rationale: The correct answer is to prepare the client for emergency surgery. The client's presentation with bright red blood in vomitus suggests active bleeding, which is a medical emergency. With a hemoglobin of 12 g/dL and a hematocrit of 35%, the client is likely experiencing significant blood loss that may require surgical intervention to address the source of bleeding. Continuing to monitor for blood loss (Choice A) is not appropriate in this acute situation where immediate action is necessary. Administering normal saline (Choice B) may help with fluid resuscitation but does not address the underlying cause of bleeding. Transfusing platelets (Choice C) is not indicated in this scenario as platelets are involved in clot formation and are not the primary treatment for active bleeding in this context.

Correct Answer: A

Rationale: Helicobacter pylori infection is the most common cause of peptic ulcers. This bacterium can weaken the protective mucous coating of the stomach and duodenum, allowing acid to get through to the sensitive lining beneath. NSAID use (Choice B) can also cause peptic ulcers by disrupting the stomach's mucosal barrier. Excessive alcohol consumption (Choice C) and stress (Choice D) can exacerbate and contribute to ulcer formation but are not the primary cause.

Correct Answer: C

Rationale: Monitoring oxygen saturation is the most important intervention in a patient with COPD because it helps assess the adequacy of oxygenation. In COPD, patients often have compromised lung function, leading to decreased oxygen levels in the blood. Monitoring oxygen saturation allows healthcare providers to promptly identify and address any potential hypoxemia, which is vital in managing COPD exacerbations. While encouraging the patient to stop smoking (Choice A) is critical for long-term management, monitoring oxygen saturation takes precedence in the immediate care of a COPD patient. Administering bronchodilators (Choice B) and providing nutritional support (Choice D) are important aspects of managing COPD but are secondary to monitoring oxygen saturation, which directly impacts the patient's oxygenation status.

Correct Answer: A

Rationale: The correct answer is Atherosclerosis. It is the primary cause of coronary artery disease, as it involves the buildup of plaque in the arteries, restricting blood flow to the heart. Hyperlipidemia (choice B) contributes to atherosclerosis by increasing cholesterol levels in the blood but is not the direct cause of coronary artery disease. Diabetes (choice C) can accelerate atherosclerosis due to high blood sugar levels, but it is not the most common cause. Smoking (choice D) is a significant risk factor for developing coronary artery disease but is not the primary cause.

Correct Answer: C

Rationale: The correct answer is C: International normalized ratio (INR). The INR is the most appropriate laboratory result to review when evaluating the effectiveness of warfarin (Coumadin) therapy. Warfarin is an anticoagulant medication, and the INR helps determine if the dosage is within a therapeutic range to prevent clotting or bleeding complications. Choice A, a Complete Blood Count (CBC), provides information about the cellular components of blood but does not directly assess the anticoagulant effects of warfarin. Choice B, Prothrombin time (PT), measures the time it takes for blood to clot but is not as specific for monitoring warfarin therapy as the INR. Choice D, Partial Thromboplastin Time (PTT), evaluates the intrinsic pathway of coagulation and is not the primary test used to monitor warfarin therapy.