Faculty Bibliography

The mechanisms of hypercapnia in eight patients with the 'Pickwickian' syndrome and obstructive sleep apnea (OSAS) were evaluated pretherapy and posttherapy (tracheostomy in seven patients and chronic nocturnal use of nasal CPAP in one). Four patients (correctors) became eucapnic within two weeks of therapy. Four others (noncorrectors) remained hypercapnic. Neither residual apneas, changes in pulmonary function, change in anatomic dead space, nor changes in ventilatory chemoresponsiveness differentiated the two groups, nor did the last three factors account for return to eucapnia in the correctors. The results indicated two separate mechanisms exist for chronic hypercapnia in OSAS: a critical balance between the ventilation during the time spent awake and hypoventilation due to apneas, a mechanism removed by treatment for obstructive apnea; and sustained hypoventilation independent of the apnea phenomenon and therefore not correctible. The subset of patients with the second mechanism appears to represent the true 'Pickwickian' syndrome and can be identified before therapy by measuring a low level of ventilation in the sustained awake state

We present the radiologic features of four patients proven to have Hermansky-Pudlak syndrome. All four patients had evidence of pulmonary involvement characterized by a progressive, diffuse, bilateral interstitial fibrosis. Extensive bullous changes were seen in one patient. Two patients with evidence of diffuse colitis exhibited an asymmetrical pattern of focal, superficial, and deep ulcerations similar to that of Crohn's disease. The association of these radiographic abnormalities with albinism, ocular abnormalities, bleeding diathesis, and Puerto Rican ancestry establishes the diagnosis

The Hermansky-Pudlak syndrome is a rare disease characterized by multisystemic involvement. Seven families with the disorder were identified in the Puerto Rican population of one municipal hospital, suggesting that the incidence in the Puerto Rican community is sufficient to warrant both dissemination of information about the disease and further investigation. The present study was an attempt to achieve both of these goals