Continuous measurement of jugular venous oxygen saturation in response to transient elevations of blood pressure in head-injured patients
- 1 March 1994
- journal article
- Published by Journal of Neurosurgery Publishing Group (JNSPG) in Journal of Neurosurgery
- Vol. 80 (3), 461-468
- https://doi.org/10.3171/jns.1994.80.3.0461
Abstract
✓ Following traumatic brain injury, continuous jugular venous oxygen saturation (SjvO2) measurements have been made and used to assess cerebral oxygenation. Transients of SjvO2 may reflect cerebral blood flow (CBF) changes if measurements are made over a short period of time during which cerebral metabolic rate for oxygen is assumed unchanged. In response to alterations in perfusion pressure, transients of SjvO2 may indicate the extent to which autoregulation has been preserved after injury. The effect of arterial pressure changes on SjvO2 was measured in 14 severely head-injured patients (Glasgow Coma Scale score < 8) within 36 hours of injury. Mean arterial blood pressure (MABP), arterial oxygen saturation, and intracranial pressure (ICP) data were also continuously recorded by a computer at the patients' bedside. The reliability of the SjvO2 oximetry measurements varied among patients, and an average 38% of SjvO2 measurements were off by more than 6% saturation, necessitating recalibration. During periods of satisfactory catheter performance, 120 instances were found in which MABP was elevated more than 8 torr (mean ± standard deviation: 32 ± 13 torr) due to endotracheal suctioning. In 94 of these measurements, there was an associated increase in the ICP of 5 torr or more, averaging 16.6 ± 10.2 torr. The SjvO2 was 0.62 ± 0.10 before the increase in MABP and rose to a peak of 0.77 ± 0.10 during the maximum MABP elevation, suggesting increased CBF during the transient hypertension. In 34 of 37 instances of persistent blood pressure elevations lasting for more than 10 minutes (mean 16.0 ± 8.0 minutes), the SjvO2 elevation persisted (average duration 15.0 ± 12.4 minutes), suggesting impaired or lost autoregulatory vasoconstriction. The presence or absence of hyperemia was unrelated to the extent of the autoregulation response. Results indicate that SjvO2 rises with increasing perfusion pressure during and after endotracheal suctioning, suggesting a feeble or absent autoregulatory response following traumatic brain injury.Keywords
This publication has 20 references indexed in Scilit:
- Continuous Monitoring of Cerebral Hemodynamic Reserve in Acute Brain InjuryPublished by Wolters Kluwer Health ,1992
- IS THE BOHR EFFECT A CONCERN IN OPTIMIZED HYPERVENTILATION?Critical Care Medicine, 1992
- JUGULAR OXYHEMOGLOBIN SATURATION VERSUS OXYGEN TENSION DURING HYPERVENTILATION IN ACUTE BRAIN TRAUMAPublished by Wolters Kluwer Health ,1991
- Continuous monitoring of cerebral oxygenation in acute brain injury: injection of mannitol during hyperventilationJournal of Neurosurgery, 1990
- Relationship between cardiac output and cerebral blood flow in patients with intact and with impaired autoregulationJournal of Neurosurgery, 1990
- Effect of posttraumatic hypoventilation on cerebral energy metabolismJournal of Neurosurgery, 1988
- Duplex scanning of the internal carotid artery: An assessment of cerebral blood flowBritish Journal of Surgery, 1987
- Effect of Hypoxia on Traumatic Brain Injury in Rats: Part 2Neurosurgery, 1987
- Effect of mannitol on ICP and CBF and correlation with pressure autoregulation in severely head-injured patientsJournal of Neurosurgery, 1984
- Dynamic changes in regional CBF, intraventricular pressure, CSF pH and lactate levels during the acute phase of head injuryJournal of Neurosurgery, 1976