nasal air pressure
Springer Online Journal Archives 1860-2000
Summary Intracranial epidural pressure (EDP) was continuously recorded in two patients with traumatic pneumocephalus. In an experimental study EDP and nasal air pressure (NAP) were recorded in other neurosurgical patients during coughing, sneezing, straining, and blowing the nose. In traumatic pneumocephalus periods of clinical deterioration—not related to infection—were found to be caused by intracranial hypertension during periods of no CSF leakage. The EDP reached levels of about 100 mm Hg. Coughing, sneezing, and straining can accelerate the exchange of CSF with air, but cannot in itself cause lasting intracranial hypertension. Blowing the nose, which is similar to a Valsalva's manoeuvre, can accelerate the exchange of CSF with air, and—with the fistula acting as a one way valve—increase the EDP level up to a maximum of about 40 mm Hg. However, the main mechanism behind the intracranial hypertension is assumed to be intracranial air causing impaired drainage of CSF either by simple mechanical blockage or by damping the forces behind the CSF dynamics. The term pneumo-hydrocephalus is descriptive of this condition. During this state of intracranial hypertension dynamic variations in intracranial pressure attributed to cerebral vasomotor instability were observed.
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