Journal of neurosurgical anesthesiology
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J Neurosurg Anesthesiol · Apr 2004
Case ReportsStrategies for managing decreased motor evoked potential signals while distracting the spine during correction of scoliosis.
Surgical correction of kyphoscoliosis may result in spinal cord injury and neurologic deficits. Monitoring somatosensory evoked potentials (SSEPs) and transcranial motor evoked potentials (MEPs) intraoperatively may allow for early detection and reversal of spinal cord injury. ⋯ Acute reduction or loss of MEP or SSEP signals during spinal distraction presents a crisis for the operative team: should distraction be immediately relieved? The authors describe three patients who showed a decrease in evoked potential signals under hypotensive, hemodiluted conditions at the stage of spinal distraction. Each case illustrates a different strategy for successful management of these patients.
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J Neurosurg Anesthesiol · Apr 2004
Randomized Controlled Trial Clinical TrialDexmedetomidine for awake carotid endarterectomy: efficacy, hemodynamic profile, and side effects.
: A randomized, double-masked, placebo-controlled study was designed to compare dexmedetomidine as a primary sedative agent with a commonly used drug combination in patients undergoing awake carotid endarterectomy (CEA). Sixty-six patients undergoing CEA (ASA II-IV) were randomly assigned to receive either dexmedetomidine (total dose of 97.5 +/- 54.7 mcg) or normal saline (control). Supplemental doses of midazolam, fentanyl, and/or propofol were administered as deemed necessary by the anesthesiologist. ⋯ These data show that the use of dexmedetomidine in patients undergoing awake CEA resulted in fewer fluctuations from the desired sedation level. Patients receiving dexmedetomidine required less antihypertensive therapy compared with the midazolam/fentanyl/propofol combination. The effect of dexmedetomidine on cerebrovascular circulation in the study population needs further investigation.
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J Neurosurg Anesthesiol · Apr 2004
Randomized Controlled Trial Clinical TrialJet injection of local anesthetic decreases pain of arterial cannulation in awake neurosurgical patients.
Arterial cannulation through the standard skin wheal of local anesthetic raised with a needle may be painful. The authors compared the efficacy of local anesthetic injected via a 25G needle versus a Bioject jet injector for arterial cannulation in awake neurosurgical patients. After institutional review board approval, 40 patients were randomized to receive 0.3 mL 1% lidocaine adjusted to pH 7.0 with NaHCO3 by Bioject with a 2-cm spacer between the syringe and skin or by 25G needle injection. ⋯ Median observer scores at injection and cannulation were 1 (range 0-2) for the needle group and 0 (range 0-2) for the Bioject group (P < 0.001). Patients in the Bioject group experienced significantly less pain during lidocaine administration and at the time of arterial cannulation by their own and by an observer's assessment than the needle injection group. Jet injection of local anesthetic should be considered prior to arterial cannulation in awake patients.
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J Neurosurg Anesthesiol · Apr 2004
Buprenorphine-soaked absorbable gelatin sponge: an alternative method for postlaminectomy pain relief.
There have been several reports of instillation of buprenorphine in the intact epidural space in an attempt to control postoperative pain, but none in which an absorbable gelatin sponge soaked with buprenorphine is placed directly in the epidural space. In the present study, carried out on 30 patients (study group) undergoing noncervical laminectomies, 0.3 mg buprenorphine diluted to 5 mL with normal saline soaked into an absorbable gelatin sponge was placed in the epidural space under direct vision. In 30 other patients (control group) undergoing laminectomies, absorbable gelatin sponge soaked with 5 mL normal saline was placed in the epidural space. ⋯ The authors observed that changes in pulse rate, mean arterial pressure, and respiratory rate were not statistically significant between the control and the study groups. The pain relief score, duration of pain relief (14.8 +/- 0.77 hours in the study group vs. 0.66 +/- 0.15 hours in the control group), and sedation were significantly better in the study group. No patient demonstrated any respiratory depression (respiratory rate <12/min), bradycardia, pruritus, or neurologic pressure symptoms, although the incidence of nausea was higher in the study group.
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J Neurosurg Anesthesiol · Apr 2004
Comparative StudyDesflurane increases intracranial pressure more and sevoflurane less than isoflurane in pigs subjected to intracranial hypertension.
Desflurane and sevoflurane may have advantages over isoflurane in neuroanesthesia, but this is still under debate. A porcine model with experimental intracranial hypertension was used for paired comparison of desflurane, sevoflurane, and isoflurane with respect to the effects on cerebral blood flow (CBF), cerebrovascular resistance (CVR), and intracranial pressure (ICP). The agents, given in sequence to each of six pigs, were compared at 0.5 and 1.0 minimal alveolar concentrations (MAC) and three mean arterial blood pressure (MAP) levels (50, 70, and 90 mm Hg) at normocapnia and one MAP level (70 mm Hg) at hypocapnia. ⋯ None of the agents abolished CO2 reactivity. High-dose desflurane resulted in a higher CBF at hypocapnia than corresponding doses of sevoflurane or isoflurane, but there were no significant differences between the agents in ICP at hypocapnia. The present study showed that desflurane increased ICP more and sevoflurane less than isoflurane during normoventilation, but the differences disappeared with hyperventilation.