Regional ventilation-perfusion study with Xe133 in cases of idiopathic kyphoscoliosis

ABSTRACT

This work was carried on ten patients with idiopathic kyphoscoliosis. Complete pulmonary functions on all the patients as well as regional ventilation/perfusion studies on five of them using Xenon [133] were done. The ventilatory defect on the studied cases was essentially that of restrictive pattern. There was no evidence of airway obstruction since the forced expiratory volume in the first second [FEV[1]] and maximum expiratory flow rate [MEFR] were with in normal. All lung volumes were reduced except the residual volume which registered a normal value. There was CO[2] retension and hypoxemia attributable to alveolar hypoventilation and ventilation/perfusion [V/Q] imbalance. The latter error was illustrated by diminusion of ventilation and perfusion of the lower lung zones that was evident in the right lung possibly due to lung compression by the scoliotic curve. The disturbance in perfusion was less than that of ventilation with the result of low V/Q ratio at the lung bases and high V/Q ratio at the upper lung zones. That was partially responsible for arterial hypoxemia