Neurological research
-
Fosphenytoin is a phenytoin prodrug that has been introduced to overcome some of the problems and limitations associated with parenteral phenytoin sodium administration. Fosphenytoin is a phosphate ester prodrug that is converted to phenytoin in vivo by peripheral esterases. ⋯ Disadvantages with fosphenytoin include rate and dose related paresthesias and pruritus, delayed decreases in blood pressure, the potential for therapeutic drug monitoring errors, and higher drug acquisition costs. In general, given the pros and cons of the new drug, fosphenytoin offers an attractive alternative for parenteral phenytoin in select individuals.
-
Near infrared optical spectroscopy is becoming a useful method for monitoring regional cerebral oxygenation status. The method is simple, reliable and noninvasive and the information which it provides is clinically significant in managing a growing number of neurological ailments. Use of this technique has been described previously by numerous authors. ⋯ There were 68 light-skinned individuals and 35 with darker skin comprising various ethnic and cultural backgrounds. Mean regional cerebral hemoglobin oxygen saturation was recorded as 67.14 +/- 8.84%. The association of the man regional cerebral hemoglobin oxygen saturation in various groups of individuals with relationship to their age, race, sex and skin color is examined.
-
Neurological research · Jan 1998
Resolving extra- and intracranial signal changes during adult near infrared spectroscopy.
Extracranial tissues have a significant effect on cerebral near infrared spectroscopy (NIRS) measurements in adults. Carotid surgery provides the opportunity to determine the relative contributions from the intra- and extracranial vascular territories. To assist, a specifically gated Laser Doppler flowmetry probe can be inserted between the NIRS optodes to co-monitor cutaneous blood flow associated with external carotid artery (ECA) clamping, whilst transcranial Doppler can be employed to monitor relative changes in the intracranial blood flow seen during internal carotid artery (ICA) clamping. ⋯ Thus an ICA-deltaHbdiff threshold of 6.8 micromol l(-1) provided a 100% specificity for SCI, whereas an ICA-deltaHbdiff < 5.0 micromol l(-1) was 100% sensitive for excluding SCI. When Total-deltaHbdiff was used without removing the ECA component, thresholds for SCI could not be resolved. NIRS can provide quantified thresholds for severe ischemia in the adult brain provided the extracranial component is removed.
-
Neurological research · Jan 1998
The effect of different ventilation regimes on jugular venous oxygen saturation in elective neurosurgical patients.
Since the concept of hyperventilation on neurosurgical and neurotraumatological patients has been contested, our analysis was aimed at its scrutiny on the basis of easily accessible parameters of perisurgical monitoring. Furthermore, the influence of an improved oxygen supply was tested on hyperventilationally induced cerebral changes and to what extent recommendations could be derived for clinical application. In 50 patients (normoventilation FiO2 = 0.4, 0.6; moderate hyperventilation up to a value of paCO2 = 31 mmHg and FiO2 = 0.4, 0.6 and 0.8), who underwent an elective neurosurgical operation at the central nervous system, a fiberoptical catheter was inserted into the bulb of the jugular vein for the continuous monitoring of the jugular venous oxygen saturation (sjvO2), additionally to the regular measures of perioperative monitoring. ⋯ Normoventilation with FiO2 = 0.6 induces a decrease of sjvO2 but also a decrease of LOI. Hyperventilation as a routine procedure during elective neurosurgery shall be applied critically and be combined with an increased inspiratory oxygen concentration if necessary. A longterm normoventilation with increased FiO2 should be avoided.
-
The use of techniques to measure cerebral oxygen saturation is gradually gaining wide popularity. The main methods available today can mainly be classified as invasive or noninvasive. ⋯ At present there is no universally accepted indication for the use of either technique but with time and wider use they are expected to become better understood. We discuss our experience and the techniques used in cerebral oximetry.