an inpatient computerized tomography of the abdomen,
40 hours after the ED central venous catheterization.
Occult pneumothoraces are thought to be more common than recognized and are attributable to the insensitivity of the postprocedure chest radiograph [20,29].
Because the detection rate of occult pneumothoraces in a delayed fashion is low, these are often published
as case reports [30–37].
One large retrospective study of 9637 outpatients with cancer receiving subclavian lines for chemotherapy found
a low incidence of delayed pneumothorax (0.4%; 95% CI, 0.3%-0.5%)
[38].
Patients in this series had been reimaged because of persistent or worsening symptoms or 24 hours after an unsuccessful insertion when a new central line was placed in the opposite subclavian vein