Follow-up studies on 3,195 patients from 161 centers in Japan undergoing
continuous ambulatory peritoneal dialysis (
CAPD) were performed for 1-104 months to clarify the incidence as well as the clinical features of acute
hydrothorax. In these studies, 50 patients (1.6%) developed this complication. Twenty-seven (54%) were men, and 23 (46%) were women, ranging in age from 6 to 79 (average 49) years. The interval between onset of
CAPD and
hydrothorax ranged from 1 day to 8 years. Four had left-sided, and 2 had bilateral
hydrothorax, but the majority (88%) were right-sided.
Dyspnea was experienced by 37 of these 50 patients, but the remaining 13 (26%) patients were asymptomatic.
Hydrothorax was fully resolved in 27 of them following a brief interruption of
CAPD or the combined use of small exchange volumes in a semi-sitting position and
pleurodesis with
tetracycline or other agents. The remaining 23 patients (46%) were switched to
hemodialysis permanently. Despite recurrence, 1 patient continued successfully on
CAPD. It was concluded that acute
hydrothorax is one important possible complication, although the risk may be low. Constant surveillance is necessary to detect
pleural effusions in patients during
CAPD.