Acta neurochirurgica. Supplement
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Acta Neurochir. Suppl. · Jan 1998
Morphological and hemodynamic evaluations by means of transcranial power Doppler imaging in patients with severe head injury.
The following conditions of 17 patients with severe head injury (ages 9-76; mean 37:12 focal and 5 diffuse injuries) were evaluated during acute phase (1-14 days after injury, mean 5) by transcranial power Doppler imaging (PDI), a new color Doppler ultrasound technique: a) morphological changes via temporal window, b) hemodynamic changes in major intracranial/cervical arteries based on measured angle-corrected time-averaged mean (TAM)/ peak velocities and vessel diameter (Va), and calculated pulsatility indices (PI), vessel area (Va), and flow volume (Vf = TAM x Va). a) 1) Major trunks of intracranial vessels and circle of Willis and pathological changes in frontal/temporal lobes and midbrain were finely visualized. 2) Contusional hemorrhage and cerebral contusion demonstrated irregular hyper- and hypo-echoic lesions, respectively. 3) Delayed epidural hematoma showed a hyper-echoic band. b) 1) Decreased velocities, significant PI increase, and Va increase tendency were observed in intracranial arteries. 2) Increased velocities with Vf increase but no Va decrease indicated hyperemia rather than vasospasm. 3) Va in the intracranial vessels, however, tended to increase PDI appears useful in evaluating real-time and simultaneous morphological and hemodynamic information in pathogenesis and neurointensive care of patients with severe head injury.
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Acta Neurochir. Suppl. · Jan 1998
Complications and safety associated with ICP monitoring: a study of 542 patients.
In our institution ICP was monitored in patients with GCS < or = 8 and abnormal CT scan: 362 severely head injured and 180 subarachnoid hemorrhage. Mean duration of monitoring was 103.6 hours (SD 74.96). Among 542 patients, 440 showed at least one episode of ICP above the threshold of 20 mm Hg. ⋯ In 13 cases (2.2%) a ventricular infection has been diagnosed. In 1 case an intraparenchimal hemorrhage related to the presence of the catheter was detected. Elevated risk of HICP and low incidence of complications have been shown in this series.
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Acta Neurochir. Suppl. · Jan 1998
Influence of hyperventilation on brain tissue-PO2, PCO2, and pH in patients with intracranial hypertension.
A harmful effect of prolonged hyperventilation on outcome has been shown in comatose patients after severe head injury. The purpose of this study was to assess the acute effect of moderate hyperventilation for treatment of intracranial hypertension (ICP < 20 mmHg) on invasively measured brain tissue-PO2 (PtiO2), PCO2 (PtiCO2) and pH (tipH) in severely head injured patients. 15 severely head injured patients (GCS < or = 8) were prospectively studied. Intracranial pressure (ICP), mean arterial blood pressure (MABP), cerebral perfusion pressure (CPP), endtidal CO2 (ETCO2), PtiO2, PtiCO2 and tipH (Paratrend or Licox microsensors) were continuously recorded using multimodal monitoring. ⋯ As well known, hyperventilation improves CPP due to a reduction in ICP. However, this does not ameliorate cerebral oxygenation as demonstrated by the decrease in PtiO2. This underlines that hyperventilation should only be used with caution in the treatment of intracranial hypertension.
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Acta Neurochir. Suppl. · Jan 1998
Effects on intracranial pressure of fentanyl in severe head injured patients.
Despite opioids are routinely used for analgesia in head injured patients, the effects of such drugs on ICP and cerebral hemodynamics remain controversial. Cerebrovascular autoregulation (CAR) could be an important factor in the ICP increases reported after opioid administration. In order to describe the effects on intracranial pressure of fentanyl and correlated such effects with autoregulation status, we studied 30 consecutive severe head injury patients who received fentanyl (2 micrograms/kg) intravenously over one minute. ⋯ In patients with preserved CAR (34.5%), opioid-induced ICP increase was greater (but not statistically significant) than in those with impaired CAR (65.5%). We conclude than fentanyl moderately increased ICP and decreased MAP and CPP. Our data suggests that in patients with preserved CAR, potent opioids could cause greater increases of ICP, probably due to activation of the vasodilatadory cascade.
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Acta Neurochir. Suppl. · Jan 1998
The use of near infrared spectroscopy (NIRS) in children after traumatic brain injury: a preliminary report.
Children commonly develop diffuse cerebral swelling after traumatic brain injury (TBI) which is believed due to a secondary response to the injury. Near infrared spectroscopy (NIRS), a continuous, direct, and noninvasive monitor of cerebral oxygenation and cerebral blood volume (CBV), could be helpful in understanding these secondary responses. The aims of our study were to determine whether NIRS used in children with severe TBI will provide insight into the pathophysiology of injury. ⋯ Often, high ICP correlated with increased THb and HbO2 indicating increased CBV and cerebrovascular dilatation. In two children, posttraumatic seizures were preceded by an unexplained rapid cerebral hyperoxygenation several hours prior to the onset of the clinical seizures. NIRS reliably detects changes in cerebral hemodynamics in children and may be used to further understand the etiology of the diffuse cerebral swelling seen in children after severe TBI.