Dural sinus pressure: various aspects in human brain surgery in children and adults.

To prevent air embolism and minimize neurosurgical venous hemorrhage, the dural sinus pressure (confluens sinuum pressure, CSP) was examined under various conditions in 47 cases, 11 of whom were children. Either the extracranial (group A) or catheter type (group B) pressure transducer was used. The latter gave approximately 30% higher values than the former. In any surgical position, children showed a tendency toward higher pressure than did adults. This was particularly the case in the sitting position; adults showed negative pressure [-8.6 +/- 2.3 (SD) mmHg, group A], whereas all eight children less than 9 yr of age (group A, 5 cases; group B, 3 cases) showed positive pressure. The youngest with negative CSP in a sitting position was a 9-yr-old boy. When the upper half of the body was raised, the CSP decreased linearly and became zero at approximately 25 degrees. In anteflexion of the neck, the CSP decreased significantly, and even with inclination of the upper half of the body of only 15-20 degrees or more upward, negative pressure was observed in adults. In children, right and left rotation of the neck showed remarkable increase of the CSP. In both supine and sitting positions, CSP was elevated sufficiently by bilateral jugular compression to prevent air embolism. Positive-pressure respiration did not raise the CSP, contrary to widely accepted knowledge. This study was originally performed in relation to brain surgery, but the results also seemed to be valuable in physiology.