Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2006
Comparative StudyClinical experience with dexmedetomidine for implantation of deep brain stimulators in Parkinson's disease.
The pharmacologic profile of the alpha-2 agonist dexmedetomidine (Dex) suggests that it may be an ideal sedative drug for deep brain stimulator (DBS) implantation. We performed a retrospective chart review of anesthesia records of patients who underwent DBS implantation from 2001 to 2004. In 2003, a clinical protocol with Dex sedation for DBS implantation was initiated. ⋯ Dex provided patient comfort and surgical satisfaction with mapping in all cases, and significantly reduced the use of antihypertensive medication (54% in the Dex group, versus 100% in controls, P = 0.048). In DBS implantation, sedation with Dex did not interfere with electrophysiologic mapping, and provided hemodynamic stability and patient comfort. Routine use of Dex in these procedures may be indicated.
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Anesthesia and analgesia · Nov 2006
Comparative StudyVariations in arterial blood pressure and photoplethysmography during mechanical ventilation.
We analyzed ventilation-induced changes in arterial blood pressure and photoplethysmography from waveforms obtained by monitoring 57 patients in the operating room and intensive care unit. Analysis of systolic and pulse pressure variations during positive pressure ventilation, DeltaUp, DeltaDown, and changes in the preejection period on both arterial and photoplethysmographic waveforms were possible in 49 (86%) patients. The pulse pressure variation and preejection period were similar when calculated using both arterial blood pressure and photoplethysmography, whereas the other variables were different. ⋯ In hypotensive patients, photoplethysmographic pulse variation >9% remained the best threshold value (pulse pressure variation >13%: area under ROC curve = 0.90; DeltaDown >5 mm Hg: area under ROC curve = 0.93) for predicting fluid responsiveness. In conclusion, this study showed that pulse variations observed in the arterial pressure waveform and photoplethysmogram are similiar in response to positive pressure ventilation. Furthermore, photoplethysmographic pulse variation > 9% identifies patients with ventilation-induced arterial blood pressure variation that is likely to respond to fluid administration.
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Anesthesia and analgesia · Nov 2006
Comparative StudyA comparison of epidural pressures and incidence of true subatmospheric epidural pressure between the mid-thoracic and low-thoracic epidural space.
Differences in epidural pressure (EP) may influence the spread of blockade in thoracic epidural anesthesia. We evaluated if EP and the incidence of subatmospheric EP differ between the mid- and low-thoracic epidural space. ⋯ We conclude that EP is lower, and the incidence of subatmospheric EP is higher in the mid-thoracic epidural space when compared with that in the low-thoracic epidural space. However, median EP was positive in both groups. It remains to be investigated whether this pressure gradient is sufficient to influence the spread of thoracic epidural blockade.
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Anesthesia and analgesia · Nov 2006
Comparative StudyLocal anesthetic-induced cardiac toxicity: a survey of contemporary practice strategies among academic anesthesiology departments.
Though new local anesthetics (LA), effective test-dosing, and new regional anesthetic techniques may have improved the safety of regional anesthesia, the optimal management plan for LA-induced cardiac toxicity remains uncertain. Accordingly, we evaluated current approaches to LA cardiotoxicity among academic anesthesiology departments in the United States. A 19-question survey regarding regional anesthesia practices and approaches to LA cardiac toxicity was sent to the 135 academic anesthesiology departments listed by the Society of Academic Anesthesiology Chairs-Association of Anesthesiology Program Directors. ⋯ The respondents were categorized into groups according to the number of peripheral nerve blocks (PNBs) performed each month: >70 PNBs (38%), 51-70 PNBs (13%), 31-50 PNBs (20%), 11-30 PNBs (23%), and <10 PNBs (6%). Anesthesia practices administering >70 PNBs were 1.7-times more likely to use ropivacaine (NS), 3.9-times more likely to consider lipid emulsion infusions for resuscitation (P = 0.008), and equally as likely to have an established plan for use of invasive mechanical cardiopulmonary support in the event of LA cardiotoxicity (NS) than low-PNB volume centers. We conclude that there are differences in the management and preparedness for treatment of LA toxicity among institutions, but the safety implications of these differences are undetermined.
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Anesthesia and analgesia · Nov 2006
Comparative StudyLumbosacral cerebrospinal fluid volume in humans using three-dimensional magnetic resonance imaging.
The clinical response to spinal anesthesia is influenced by lumbosacral cerebrospinal fluid (CSF) volume, which is highly variable among patients. ⋯ Application of this technique to clinical investigations may further enhance our understanding of spinal anesthesia.