Evaluation of a regional oxygen saturation catheter for monitoring SJVO2 in head injured patients

1996 ◽  
Vol 12 (4) ◽  
pp. 285-291 ◽  
Author(s):  
Ann M. Ritter ◽  
Shankar P. Gopinath ◽  
Charles Contant ◽  
Raj K. Narayan ◽  
Claudia S. Robertson
Keyword(s):  
Oxygen Saturation ◽  
Regional Oxygen Saturation ◽  
Head Injured ◽  
Injured Patients

Monitoring of cerebral oxygenation in patients with severe head injuries: brain tissue PO2 versus jugular vein oxygen saturation

1996 ◽  
Vol 85 (5) ◽  
pp. 751-757 ◽  
Author(s):  
Karl L. Kiening ◽  
Andreas W. Unterberg ◽  
Tillman F. Bardt ◽  
Gerd-Helge Schneider ◽  
Wolfgang R. Lanksch
Keyword(s):  
Oxygen Saturation ◽  
Cerebral Oxygenation ◽  
Jugular Vein ◽  
Head Injuries ◽  
Jugular Bulb ◽  
Cerebral White Matter ◽  
Content Type ◽  
Head Injured ◽  
Injured Patients ◽  
Fine Print

✓ Monitoring of cerebral oxygenation is considered to be of great importance in minimizing secondary hypoxic and ischemic brain damage following severe head injury. Although the threshold for cerebral hypoxia in jugular bulb oximetry (measurement of O2 saturation in the jugular vein (SjvO2)) is generally accepted to be 50% oxygen saturation, a comparable value in brain tissue PO2 (PtiO2) monitoring, a new method for direct assessment of PO2 in the cerebral white matter, has not yet been established. Hence, the purpose of this study was to compare brain PtiO2 with SjvO2 in severely head injured patients during phases of reduced cerebral perfusion pressure (CPP) to define a threshold in brain PtiO2 monitoring. In addition, the safety and data quality of both SjvO2 and brain PtiO2 monitoring were studied. In 15 patients with severe head injuries, SjvO2 and brain PtiO2 were monitored simultaneously. For brain PtiO2 monitoring a polarographic microcatheter was inserted in the frontal cerebral white matter, whereas for SjvO2 measurements were obtained by using a fiberoptic catheter placed in the jugular bulb. Intracranial pressure was monitored by means of an intraparenchymal catheter. Mean arterial blood pressure, CPP, end-tidal CO2, and arterial oxygen saturation (pulse oximetry) were continuously recorded. All data were simultaneously stored and analyzed using a multimodal computer system. For specific analysis, phases of marked deterioration in systemic blood pressure and consecutive reductions in CPP were investigated. There were no complications that could be attributed to the PtiO2 catheters, that is, no intracranial bleeding or infection. The “time of good data quality” was 95% in brain PtiO2 compared to 43% in SjvO2; PtiO2 monitoring could be performed twice as long as SjvO2 monitoring. During marked decreases in CPP, SjvO2 and brain PtiO2 correlated closely. A significant second-order regression curve of SjvO2 versus brain PtiO2 (p < 0.01) was plotted. At a threshold of 50% in SjvO2, brain PtiO2 was found to be within the range of 3 to 12 mm Hg, with a regression curve “best fit” value of 8.5 mm Hg. There was a close correlation between CPP and oxygenation parameters (PtiO2 and SjvO2) when CPP fell below a breakpoint of 60 mm Hg, suggesting intact cerebral autoregulation in most patients. This study demonstrates that monitoring brain PtiO2 is a safe, reliable, and sensitive diagnostic method to follow cerebral oxygenation. In comparison to SjvO2, PtiO2 is more suitable for long-term monitoring. It can be used to minimize episodes of secondary cerebral maloxygenation after severe head injury and may, hopefully, improve the outcome in severely head injured patients.

Continuous measurement of jugular venous oxygen saturation in response to transient elevations of blood pressure in head-injured patients

1994 ◽  
Vol 80 (3) ◽  
pp. 461-468 ◽  
Author(s):  
John B. Fortune ◽  
Paul J. Feustel ◽  
Carl G. M. Weigle ◽  
A. John Popp
Keyword(s):  
Blood Pressure ◽  
Traumatic Brain Injury ◽  
Brain Injury ◽  
Oxygen Saturation ◽  
Perfusion Pressure ◽  
Endotracheal Suctioning ◽  
Jugular Venous Oxygen Saturation ◽  
Head Injured ◽  
Venous Oxygen Saturation ◽  
Injured Patients

✓ 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.

Verbal learning deficits following severe head injury: heterogeneity in recovery over 1 year

1991 ◽  
Vol 75 (Supplement) ◽  
pp. S50-S58 ◽  
Author(s):  
Ronald M. Ruff ◽  
David Young ◽  
Theresa Gautille ◽  
Lawrence F. Marshall ◽  
Jeff Barth ◽  
...  
Keyword(s):  
Memory Performance ◽  
Verbal Learning ◽  
Data Bank ◽  
Learning Deficits ◽  
Content Type ◽  
Recovery Curve ◽  
Recovery Curves ◽  
Head Injured ◽  
Injured Patients ◽  
Case Basis

✓ A total of 40 severely head-injured patients were selected from the Traumatic Coma Data Bank, supported by the National Institute of Neurological Disorders and Stroke, to analyze the recovery of verbal learning across baseline and 6- and 12-month evaluations postinjury. During the initial 6 months, the group demonstrated marked recovery, followed by an absence of improvement over the latter part of the year. Analysis of this recovery curve on a case by case basis revealed three recovery subtypes: namely, a flat curve, a peak-drop curve, or an improvement curve. These three subtypes proved to have concurrent validity when compared with another memory test. Adding 19 new patients to the sample cross-validated the subtypes. However, the memory performance of the 59 patients was dissociated from other neuropsychological tests which showed recovery at more equivalent rates across the subtypes. Analysis of the demographic and neurological characteristics disclosed that the group with a peak-drop recovery curve was less well educated and the group with a flat curve demonstrated a trend toward higher levels of hypoxia. Moreover, the three subgroups were rated by their relatives to have equivalent levels of depression at baseline and at 6 months, but only the improved subgroup demonstrated reduced depression at 1 year. The clinical relevancy of these differential recovery curves is discussed.

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