Subdural Blood Patch for the Treatment of Persistent CSF Leak After Permanent Intrathecal Catheter Implantation: A Report of Two Cases

A CSF leak that persists despite conservative therapy may significantly increase the morbidity associated with implantable intrathecal drug delivery systems. This report presents 2 cases where the application of a subdural blood patch led to the satisfactory resolution of a persistent CSF leak after previous epidural blood patches had failed.

Comparison between plethysmographic and forced oscillation techniques in the assessment of airflow obstruction

We compared airway resistances (Raw, body plethysmograph) and total pulmonary resistance at 4 and 24 Hz (RRS 4 Hz, 24 Hz) as well as the resonant frequency (RF), both in normals and in patients with airway obstruction. Bronchodilatation (n = 38) was the best evaluated by the induced changes in RRS 4 Hz and RF. However, the importance of change of RRS 4 Hz was poorly correlated with the change in Raw. Bronchial challenge test with histamine and DPT was again the best evaluated by RRS 4 Hz and RF with maximal changes observed for the latter. Normal ranges for Raw, RRS 4 Hz and RF were computed (n = 41). For all patients studied (n = 42) concordance for abnormality was good but poor for normality. From this we conclude that the oscillation technique is a different approach for the evaluation of airway obstruction and that RRS 4 Hz or RF are easy and accurate measurements to follow during bronchodilatation and bronchoconstriction tests.