True about primary pulmonary hypoventilation is:
Answer is A (Does not respond to chemical stimuli): Ventilatory responses to chemical stimuli are reduced or absent- Harrison 161/1/1570 Primary pulmonary hypoventilation Characterized by: Impaired chemoreception resulting in decreased ventilatory drive. Chronic hypercapnia and hypoxemia in the absence of identifiable neuromuscular disease or mechanical ventilatory impairment. Presentation : Occurs in all age groups but majority of cases have been repoed in males aged 20-50 years. Early: lethargy, fagtigue, daytime somnolence, disturbed sleep and morning headache. Late: Cyanosis polycythemia, pulmonary hypeension, congestive hea failure. Note : Dyspnea is uncommon despite severe aerial blood gas derangements because of impaired chemotherapy. Diagnosis : The key diagnostic feature is respiratory acidosis in the absence of respiratory muscle weaknesses or impaired ventilatory mechanics.
Does not respond to chemical stimuli
Hypocapnoea and normal PaO2
Common in children
Respiratory alkalosis is diagnostic