Mildly abnormal intracranial pressure (ICP) waveform.
Mild, abnormal ICP waveform during external ventricular drain (EVD) clamp trial with clustering of P1 to P3 waves. Respiratory variations are noted as well as Valsalva maneuver. The patient has muscle resistance testing of his deltoid, which causes the patient to perform the Valsalva maneuver and transiently increase ICP. Inspiration causes a decrease in ICP, and Valsalva maneuver during segmental muscle strength testing increases it.
W. David Freeman, MD, FSNS, FAAN
CONTINUUM: Lifelong Learning in Neurology. 21(5, Neurocritical Care):1299-1323, October 2015