Correct Answer: C

Rationale: In a patient with ARDS who is experiencing refractory hypoxemia despite maximal ventilatory support and prone positioning, the use of extracorporeal membrane oxygenation (ECMO) is a potentially life-saving adjunctive therapy. ECMO works by providing temporary support for gas exchange outside the body, allowing the lungs to rest and heal while providing adequate oxygenation and carbon dioxide removal. The use of ECMO has been associated with improved oxygenation and reduced mortality in severe cases of ARDS, especially in patients who fail conventional therapies. High-frequency oscillatory ventilation (HFOV) has not consistently shown mortality benefit in ARDS, continuous renal replacement therapy (CRRT) is not directly indicated for hypoxemia in ARDS, and inhaled nitric oxide (iNO) has shown limited benefit in improving oxygenation in ARDS without a clear impact on mortality.

Correct Answer: C

Rationale: Cryptosporidium parvum is a protozoan parasite that commonly causes waterborne illness characterized by watery diarrhea, abdominal cramps, and nausea. This parasite is often transmitted through contaminated water sources such as streams or lakes. Laboratory tests identifying oocysts in the stool sample are indicative of Cryptosporidium infection. Giardia lamblia can also cause similar symptoms, but the presence of oocysts points more towards Cryptosporidium in this case. Entamoeba histolytica causes amoebic dysentery with bloody diarrhea and is usually associated with fecal-oral transmission through contaminated food or water. Cyclospora cayetanensis typically causes prolonged watery diarrhea and is associated with the ingestion of contaminated food or water.

Correct Answer: D

Rationale: Thrombocytopenia is a condition characterized by a low platelet count, which can lead to an increased risk of bleeding. Patients with thrombocytopenia are at risk for injury due to potential bleeding complications. Therefore, the appropriate nursing diagnosis to protect the patient from further injury in this case would be "Risk for injury related to thrombocytopenia." This nursing diagnosis allows the nurse to assess for signs of bleeding, implement interventions to prevent injury, and closely monitor the patient's platelet levels to prevent complications.

Correct Answer: A

Rationale: The presentation described is consistent with anterior uveitis. Anterior uveitis involves inflammation of the iris and ciliary body. Patients typically present with symptoms such as redness, pain, photophobia, and blurred vision. The slit-lamp examination findings of ciliary injection (redness and dilation of blood vessels in the iris and ciliary body), corneal edema, and a mid-dilated pupil with a fixed reaction to light (due to ciliary muscle spasm causing decreased accommodation) are characteristic of anterior uveitis. This condition is often idiopathic but can be associated with various systemic diseases like ankylosing spondylitis, inflammatory bowel disease, and other autoimmune disorders. Treatment involves addressing the inflammation with topical corticosteroids and, in some cases, cycloplegic agents to reduce pain and inflammation.

Correct Answer: C

Rationale: Naloxone, also known by the brand name Narcan, is used to reverse the effects of opioid overdose. Opioids can cause respiratory depression, sedation, and other signs of toxicity. Administering naloxone can quickly reverse these effects, restoring the patient's breathing and consciousness. This makes it the appropriate choice for reversing all signs of toxicity related to opioids. Digibind (Digoxin) is used to reverse toxicity from digoxin specifically. Atropine sulfate is used for bradycardia. Diazepam (Valium) is a benzodiazepine used for anxiety, seizures, and muscle relaxation, not for reversing toxicity.