Intracranial compliance as a bed-side monitoring technique in severely head-injured patients.
A recently developed monitoring technology makes an on-line assessment of intracranial compliance (ICC) possible. Aims of our research: 1. Course and values of ICC (critical threshold: < 0.5 ml/mmHg) in episodes of pathological intracranial pressure (ICP) (> 20 mmHg) and reduced cerebral oxygenation (brain tissue PO2 (PtiO2) < 10 mmHg). 2. Mean ICC in different ages. 3. Relationship between ICC and outcome. 4. Evaluation of ICC as routine monitoring parameter by calculation of s.c. time-of-good-data-quality (TGDQ). Computer data assessment of 7 patients with severe closed head-injury was performed providing 830 hours of data. TGDQ resulted from the formula: TGDQ (%) = artifact free time (min) x 100 (%)/total monitoring time (min). Outcome was assessed 6 months posttrauma (Glasgow Outcome Score (GOS). 1. Analysis revealed 43 episodes of pathologically elevated ICP and 39 of critical ICC. In 17 cases overlapping periods were found. In 9 of these ICC preceded ICP. Reduced cerebral oxygenation was neither related with high ICP nor low ICC. 2. ICC was found to be age-related. At a cut-off-point of 20 mmHg in ICP, ICC in children (< or = 16 years) was 0.9, in adults (17-60 years) 0.7 and in elderly (> 60 years) 0.6 ml/mmHg. 3. Adverse outcome was indicated best by high ICP (up to 45% of monitoring time) followed by low ICC (up to 41% of monitoring time). 4. TGDQ in ICC was 72% compared to 95% in ICP and 98% in PtiO2. In predicting adverse outcome, ICP was equal to ICC. The different ICC in each age class points to the need of age-adjusted thresholds. Further refinements of ICC technology are needed to improve ICC data quality and therefore become a useful tool in neuromonitoring.
Kiening
K L
KL
Department of Neurosurgery, Charité, Virchow Medical Center Humboldt-University at Berlin, Germany.
Schoening
W N
WN
Lanksch
W R
WR
Unterberg
A W
AW
D000293:Adolescent; D000328:Adult; D000368:Aged; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D006259:Craniocerebral Trauma / Q000503:physiopathology*; D015600:Glasgow Coma Scale; D006801:Humans; D019586:Intracranial Hypertension / Q000175:diagnosis / Q000503:physiopathology*; D007427:Intracranial Pressure / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic / Q000379:methods*; D010100:Oxygen / Q000097:blood; D019095:Point-of-Care Systems; D012151:Resuscitation
D010100:Oxygen