Articles: monitoring.
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J Clin Monit Comput · Jan 1998
ReviewPulse oximetry monitoring and late postoperative hypoxemia on the general care floor.
Hypoxemia has long been recognized as a risk to patients in the operating room and postanesthesia care unit, and hemoglobin oxygen saturation (HbO2) monitoring with pulse oximetry has become a standard of care in these areas. There is growing evidence, however, suggesting that later postoperative hypoxemia also may play a role in organ dysfunction leading to morbidity and mortality. ⋯ In this environment, telemetric pulse oximetry monitoring may represent a cost-effective approach to maximizing quality of care while enhancing risk management. This review discusses late postoperative hypoxemia and identifies areas for further investigation.
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J Neurosurg Anesthesiol · Jan 1998
Clinical TrialDoppler color-flow imaging: screening of a patent foramen ovale in children scheduled for neurosurgery in the sitting position.
A patent foramen ovale (PFO) is the most common cause of paradoxical air embolism during neurosurgical procedures in the posterior fossa in the sitting position in both adults and children. To detect right-to-left shunting, we performed Doppler color-flow imaging preoperatively in 30 children scheduled for neurosurgical procedures in the sitting position. ⋯ Venous air embolism occurred in 9 of 24 (37%) children operated on in the sitting position and in none of the 6 children operated on in a nonsitting position. We conclude that Doppler color-flow mapping could be a useful noninvasive technique to screen children scheduled for neurosurgery in the sitting position for the presence of a PFO.
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Electroencephalogr Clin Neurophysiol · Jan 1998
ReviewNeuromonitoring in the operating room: why, when, and how to monitor?
This review considers the main principles and indications of EEG and evoked potential (EP) neuromonitoring in the operating room. Neuromonitoring has a threefold purpose: to warn the surgeon that he has to adjust his strategy, to confirm his decision, and to help him improve subsequent procedures. The pathophysiology of intraoperative events liable to alter the EEG or the EPs is first considered. ⋯ Knowledge of them is essential to disentangle these neurophysiological alterations due to intraoperative events from those merely due to anesthesia and to use neurophysiological parameters to evaluate the depth of anesthesia. Third, the main indications and limitations of neuromonitoring are considered: prevention of ischemic brain or spinal cord damage, prevention of mechanical injuries of the brain, spinal cord or peripheral nerve, and localization of the motor cortex in cortical neurosurgery or of cranial nerves in posterior fossa surgery. Finally, the 3 levels of neuromonitoring (neurophysiological feature extraction, neurophysiological pattern recognition, clinical integration of the neurophysiological patterns) are discussed together with the rules that should guide the dialogue between the surgeon, the anesthesiologist, and the neurophysiologist.
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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.
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Acta Neurochir. Suppl. · Jan 1998
Comparative StudyCerebral oxygenation in contusioned vs. nonlesioned brain tissue: monitoring of PtiO2 with Licox and Paratrend.
Brain tissue PO2 in severely head injured patients was monitored in parallel with two different PO2-microsensors (Licox and Paratrend). Three different locations of sensor placement were chosen: (1) both catheters into non lesioned tissue (n = 3), (2) both catheters into contusioned tissue (n = 2), and (3) one catheter (Licox) into pericontusional versus one catheter (Paratrend) into non lesioned brain tissue (n = 2). Mean duration of PtiO2-monitoring with both microsensors in parallel was 68.1 hours. ⋯ During a critical reduction in cerebral perfusion pressure (< 60 mm Hg), PtiO2 decreased measured with both microsensors. Elevation of inspired oxygen fraction, normally followed by a rapid increase in tissue PO2, only increased PtiO2 when measured in pericontusional and nonlesioned brain. To recognize critical episodes of hypoxia or ischemia, PtiO2-monitoring of cerebral oxygenation is recommended in nonlesioned brain tissue.