The WBC count was 7.78 × 103 cells/μL, with 60% neutrophils, 31% lymphocytes, 5% monocytes, and 3% basophils. The hemoglobin level was 16.8 g/dL, and the hematocrit was 51.6%. The platelet count was 213 × 103 cells/μL. Other laboratory investigations performed at hospital admission included measurement of electrolyte levels, renal and liver function tests, and measurement of blood sugar levels, the results of which were all within normal limits. Results of arterial blood gas analysis on room air showed the following: pH, 7.39; Paco2, 39 mm Hg; and Pao2, 65 mm Hg. A spirogram was obtained showing the following: FEV1, 1.26 L (55% of predicted); FVC, 1.48 L (49% of predicted); and FEV1/ FVC ratio, 85%. A posteroanterior chest radiograph demonstrated a markedly elevated right hemidiaphragm. There was no apparent intrathoracic cause related to a mediastinal mass or atelectasis (Fig 1
). A chest CT scan at the level of the inferior pulmonary veins confirmed that the right hemidiaphragm was considerably elevated. There were no signs of pulmonic effusion or subdiaphragmatic space-occupying process. Subsegmental areas of atelectasis due to basal hypoventilation were noted. A sniff test was performed showing a paradoxical upward motion of the right hemidiaphragm. The right hemidiaphragmatic paralysis was confirmed by ultrasound, which demonstrated paradoxical hemidiaphragmatic motion.