Immediate postoperative PAH is seen following cardiopulmonary surgery in a patient with congenital heart disease.
Mechanisms:
(1) sudden increase in pulmonary vascular resistance
(2) sudden increase in pulmonary airway resistance
(3) worsening of the ventilation to perfusion matching
Manifestations during or shortly after the surgery:
(1) acute right ventricular failure
(2) decreased heart output
(3) systemic hypotension
(4) metabolic acidosis
(5) cardiac ischemia if there is decreased perfusion of the coronary arteries
(6) hypoxemia
Management strategies:
(1)administering vasodilators to the pulmonary artery to lower the pulmonary artery pressure
(1a) inhaled nitric oxide
(1b) inhaled epoprostenol
(1c) phosphodiesterase inhibitors
(2) reducing right ventricular afterload
(3) optimizing fluid balance
(4) improving cardiac output if low
(5) optimizing sedation and pain management
(6) correcting acidosis
(7) improving oxygenation
(8) surgically correcting any residual anatomic abnormalities that may be present
