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S Prokop

Publications and source records attributed to S Prokop.

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Cerebral oxygenation and systemic trauma related factors determining neurological outcome after brain injury.

We examined the relationship between clinical and radiological findings, cerebral oxygenation patterns during intensive care management, presence of systemic trauma related injuries and severity of illness in 50 patients (age: 32.3 +/- 12 years, GCS: 8 +/- 4) who were rescued from the accident scene within a 30 min period after trauma. Presence of systemic injuries was quantified using the Injury Severity Score (ISS) and severity of illness was scored using the Acute Physiology and Chronic Health Evaluation (APACHE II). Cerebral oxygenation parameters included continuous monitoring of jugular bulb oxygen saturation (SjvO(2)) for 12 840 h, and 2323 periodical blood sampling for measurement of arteriovenous differences in oxygen content (AVDO(2)), arteriovenous difference of lactate (AVDL) and lactate oxygen index (LOI). Fifteen patients (30%) presented with anisocoria or non-reacting pupils. Diffuse lesions on computed tomography (CT) were found in 34% of the patients and in 66% a mass lesion was removed. The mean ISS was 28 +/- 15.3 and 34 patients (68%) had an APACHE II score between 20 and 29 (mean 24 +/- 15). No statistically significant association between age (P = 0.45), gender (P = 0.83), initial Glasgow Coma Score (GCS) (P = 0.43), episodes of cerebral perfusion pressure (CPP) < 70 mm Hg (P = 0.8), ISS (P = 0.28), pupillary abnormalities (P = 0.57), initial CT findings (P = 0.74), APACHE II scores (P = 0. 36) and outcome could be demonstrated. The number of SjvO(2)desaturations (< 60%) was the only statistically significant factor associated with outcome (P = 0.05). The percentage of patients with poor neurological outcomes (GOS 1-3) was 38% in patients with no or one desaturation episode, and 57.6% in those with multiple desaturations. In conclusion, in patients who are resuscitated early and quickly transferred to the hospital, the number of SjvO(2)desaturations during intensive care management might be associated with outcome more strongly than other clinical and radiological features.

APACHE↗

Correlation between jugular bulb oxygen saturation and partial pressure of brain tissue oxygen during CO2 and O2 reactivity tests in severely head-injured patients.

PURPOSE: To correlate the jugular bulb oxygen saturation (SjvO2) and brain tissue oxygen pressure (PbtO2) during carbon dioxide (CO2) and oxygen (O2) reactivity tests in severely head-injured patients. METHODS AND RESULTS: In nine patients (7 men, 2 women, age: 26 +/- 6.5 years, GCS of 6.5 +/- 2.9), a polarographic microcatheter (Clark-type) was inserted into nonlesioned white matter (frontal lobe). PbtO2 and SjvO2 were monitored simultaneously and cerebral vasoreactivity to CO2 and O2 was tested on days three, five and seven after injury. Simultaneous measurements of vasoreactivity by transcranial Doppler (TCD) were undertaken. A total of twenty-one CO2 and O2 reactivity tests were performed. Critical values of PbtO2 (< 15 mm Hg) during induced hyperventilation could be observed four times in two patients. High PbtO2 values up to 80 mm Hg were observed during hyperoxygenation (FiO2 100%). CO2 vasoreactivity by means of PbtO2 was absent in four tests in which measurements by TCD showed intact responses. A stronger correlation between SjvO2 and PbtO2 during the O2 reactivity tests was observed (r = 0.6, p < 0.001), in comparison to values obtained during the CO2 reactivity tests (r = 0.33, p < 0.001). In addition, there was no statistically significant correlation (r = 0.22, p = 0.26) between CO2 reactivity values measured by TCD (4.5 +/- 5.7%) and PbtO2 (3 +/- 2.8%). CONCLUSIONS: Correlation between SjvO2 and PbtO2 during CO2 reactivity test is low, even if significant differences between normo- and hyperventilation values are present. In comparison to SjvO2, monitoring of PbtO2 might more accurately detect possible focal ischaemic events during rapidly induced hyperventilation in severely head-injured patients. The CO2 vasoreactivity by means of changes in Vm MCA seems to be higher in comparison to changes of PbtO2. These observations lead to the hypothesis that vasoreactivity measured by TCD overestimates the cerebrovascular response to CO2.

Adolescent↗