Relationship between Rapid Variations in Intracranial Pressure and Changes in Respiratory Pattern during Postoperative Monitoring

Correlation between changes in epidural pressure, respiration and other related phenomena were studied in 7 patients with brain tumor by post-operative monitorings. Mutual changes in intracranial pressure (ICP) and respiratory pattern during rapid ICP variations were the main focus of our study. Occurrence of rapid ICP variations of A and B-waves was closely related to changes in respiratory pattern. In large plateau-like waves, suppression in respiration usually initiated the pressure rise, while hyperpnea or tachypnea accounted for the pressure decrease. Analysis on B-type pressure oscillation disclosed a clear phase relation that ICP rises during hypopneic phase of periodic respiration and its reduction coincides with the onset of hyperpnea. Noticeably such pressure variations as well as respiratory oscillations appeared dominant during sleep. Thus it is indicated that, under pathologic conditions, occurrence of oscillating respiration is provoked by depression in wakefulness of patients, presumably accompanying changes in the function of respiratory centers, and affects the changes in ICP.