Influence of oxygen supply upon vegetative functions during increased intracranial pressure

Abstract

A comparison was made between two series of experimental animals in whom ICP increase was produced and the influence of controlled ventilation upon the course of CVP, BP, I-IR, EEG, ICP, and blood gases was studied. CVP, BP, and HR are not influenced significantly by controlled ventilation. Isoelectric EEG changes, brain stem anoxia, and maximal increase of intracranial pressure occur significantly later in the group of ventilated than in the group of non-ventilated animals.Clinical observations and experimental studies have shown that alterations of respiratory function and significant changes of bloodgas parameters are some of the earliest effects of increased intracranial pressure (ICP)s, 28, 29, 37, 40. It has also been shown that artificial ventilation, with subsequent changes in blood gases, particularly the arterial partial pressure of carbondioxide (pCO2) and oxygen (pO2), influence the increased ICP, the cerebrovascular autoregulation, and the mortality, both in man and in experimental animals with acutely or subacutely increased ICP 2, r, ~3, 32, 33. 36, 89 On the other hand, Jenett and North (1975), as well as Valtonen (1975), found no significant influence of ICP upon blood gases, and Christensen et al. (1975) and Krenn et al. (1975) reported that controlled artificial ventilation did not influence patient's mortality.The aim of the present study was to investigate the influence of increased ICP upon the course of the vegetative parameters in conditions of adequate oxygen supply.