A patient with chronic respiratory failure secondary to severe restrictive lung disease requires long-term oxygen therapy to maintain adequate oxygenation. Which of the following oxygen delivery devices is most appropriate for delivering continuous supplemental oxygen in this patient?

Correct Answer: D

Rationale: The most appropriate oxygen delivery device for a patient with chronic respiratory failure secondary to severe restrictive lung disease requiring continuous supplemental oxygen is a non-rebreather mask. A non-rebreather mask is designed to deliver high-flow oxygen and is typically used for short-term medical treatment in emergency situations or for critically ill patients. It is ideal for providing the highest concentration of oxygen available for inhalation, making it suitable for patients with severe hypoxemia.

Correct Answer: B

Rationale: Vitamin K is essential for the production of several clotting factors in the liver, including factors II, VII, IX, and X. In a patient with chronic liver disease, impaired liver function can lead to decreased synthesis of these clotting factors. As a result, there is an underlying deficiency of these clotting factors, leading to prolonged PT (prothrombin time) and aPTT (activated partial thromboplastin time). The mixing studies showing correction with normal plasma further support the diagnosis of a factor deficiency rather than an inhibitor, which helps in ruling out conditions like DIC or hemophilia.

Correct Answer: A

Rationale: The combination of recurrent joint pain, swelling, and limited range of motion in multiple joints along with elevated ESR, positive RF, and presence of anti-CCP antibodies is classic for rheumatoid arthritis (RA). Elevated ESR indicates inflammation, positive rheumatoid factor (RF) is an autoantibody commonly found in the serum of patients with RA, and the presence of anti-cyclic citrullinated peptide (anti-CCP) antibodies further supports the diagnosis of RA. These laboratory findings along with the clinical presentation are highly suggestive of rheumatoid arthritis. Systemic lupus erythematosus (SLE), ankylosing spondylitis (AS), and psoriatic arthritis (PsA) can have overlapping symptoms with RA, but the specific combination of elevated ESR, positive RF, and anti-CCP antibodies points more towards RA in this scenario.

Correct Answer: B

Rationale: Vestibular neuritis is a condition characterized by the acute onset of severe vertigo, nausea, vomiting, and nystagmus. These symptoms are typically worsened by head movement. Vestibular neuritis is caused by inflammation of the vestibular nerve, which plays a key role in balance and spatial orientation. The classic presentation of these symptoms, along with the absence of hearing loss (which is seen in labyrinthitis), points towards vestibular neuritis as the most likely cause in this scenario. Meniere's disease presents with recurrent episodes of vertigo, hearing loss, tinnitus, and sensation of fullness in the ear. Benign paroxysmal positional vertigo (BPPV) is characterized by brief episodes of vertigo triggered by changes in head position.

Correct Answer: C

Rationale: The symptoms described, including progressive weakness, muscle atrophy, fasciculations, dysphagia, and dysarthria primarily involving the upper and lower extremities, are classic features of amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease. ALS is a progressive neurodegenerative disorder that affects the motor neurons in the brain and spinal cord, leading to muscle weakness and atrophy. As the disease progresses, patients may develop difficulty swallowing (dysphagia) and speaking (dysarthria). In contrast, Parkinson's disease primarily involves movement-related symptoms such as tremors, muscle stiffness, and slow movements. Guillain-Barré syndrome (GBS) is an acute inflammatory demyelinating polyneuropathy that typically presents with ascending weakness and sensory abnormalities, often preceded by an infection. Myasthenia gravis is characterized by muscle weakness exacerbated by