A patient presents with symptoms of severe allergies, including difficulty breathing, hives, and swelling. Which of the following cells is primarily responsible for mediating these allergic responses?

Correct Answer: C

Rationale: Mast cells are primarily responsible for mediating allergic responses such as severe allergies. When an allergen triggers the immune response, mast cells release histamine, leukotrienes, and other inflammatory mediators. These substances cause symptoms such as difficulty breathing, hives, and swelling. Basophils also release histamine, but mast cells are more abundant in tissues and play a significant role in allergic reactions. Eosinophils are involved in allergic reactions but are more focused on combating parasitic infections. Neutrophils are not typically involved in allergic responses but play a key role in combating bacterial infections.

Correct Answer: A

Rationale: Fluticasone/salmeterol (Advair) is a combination medication consisting of an inhaled corticosteroid (fluticasone) and a long-acting beta-agonist (salmeterol). This combination medication is recommended for long-term control of asthma symptoms and for the prevention of exacerbations. Fluticasone reduces airway inflammation, while salmeterol helps to relax the muscles of the airways, improving breathing. Using this combination medication regularly can help manage asthma symptoms and reduce the risk of asthma attacks. It is not appropriate to use short-acting beta-agonists like albuterol (salbutamol) on a long-term basis for asthma control. Ipratropium bromide (Atrovent) is an anticholinergic bronchodilator that is more commonly used for chronic obstructive pulmonary disease (COPD

Correct Answer: B

Rationale: CPAP therapy is considered the gold standard treatment for obstructive sleep apnea (OSA) and is the most appropriate intervention for managing OSA and improving symptoms. CPAP therapy involves using a machine that delivers a continuous flow of air through a mask worn over the nose or mouth during sleep. This air pressure helps keep the airway open, preventing the collapse that causes apneas and snoring during sleep.

Correct Answer: A

Rationale: Patients with COPD are at increased risk for developing ventilator-induced lung injury (VILI) due to their underlying lung pathology. Using a low tidal volume strategy (6-8 ml/kg predicted body weight) has been shown to reduce the risk of VILI in these patients. Additionally, applying high positive end-expiratory pressure (PEEP) helps to recruit collapsed alveoli, improve oxygenation, and decrease the risk of barotrauma by keeping the alveoli open throughout the respiratory cycle. Therefore, the most appropriate ventilator settings to minimize the risk of VILI in a COPD patient with acute exacerbation and respiratory failure requiring mechanical ventilation would be low tidal volume and high PEEP.

Correct Answer: A

Rationale: Aplastic anemia is a condition characterized by a reduction in the number of all three blood cell types: red blood cells, white blood cells, and platelets. The patient's presentation of bone pain, fatigue, frequent infections, pancytopenia (decreased counts of all blood cell types), hypocellular bone marrow (reduced cellularity in the bone marrow), and absence of reticulocytes is indicative of aplastic anemia.