Articles: brain-injuries.
-
The present study was desined to clarify the roles of artificial hyperventilation in management of the patients with cerebral injury. Here reported is the first part of the serial studies and concerned with general informations about hyperventilation. The measurements of PaCO2, minute ventilation volume (VE), dead space (VD), tidal volume (VT), cardiac output (by dye dilution method), oxygen consumption (by Fick' principle) and oxygen equilibrium were performed in the patients suffering from acute, severe head injury. ⋯ The changes of artero-mixed venous oxygen saturation difference which were calculated at 100 mmHg of PaO2 and 40mmHg of mixed venous PO2 were in a linear fashion with those of P50. Apart from the problems on injured brain, the beneficial and non-beneficial effects of hyperventilation were further discussed. The availability and inidcation of artificial hyperventilation should be precisely evaluated later, in a comprehensive manner with the subsequent studies (Part 2 and 3) on cerebral metabolism and intracranial pressure.
-
Acta neurochirurgica · Jan 1975
The relation between intracrainal pressure, mean arterial pressure and cerebral blood flow in patients with severe head injury.
In patients with severe head injuries ICP, MAP and CBF were measured continuously. In most patients there was a positive vasopressor response to increasing ICP, but the ICP/MAP ratio varied considerably in individual cases. CBF was diminished either by increasing ICP or by decreasing MAP. This effect was more marked with ICP above 40 mm Hg or MAP below 110 mm Hg. In terminal stages there was often a negative MAP/ICP ratio accompanied by massive cerebral hyperaemia. Key words: Severe head injury--intracranial pressure--mean arterial pressure--cerebral blood flow--cerebral perfusion pressure--critical limit of ICP and CBF. ⋯ ICP equals intracranial pressure (mm Hg); CBF, Flow equals cerebral blood flow (ml/min); MAP equals mean arterial pressure (mm Hg); CPP equals cerebral perfusion pressure (mm Hg) (difference between MAP and ICP); BP equals blood pressure.