Anesthesia and analgesia
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Anesthesia and analgesia · Dec 2007
Comparative StudyThe relationship between current intensity for nerve stimulation and success of peripheral nerve blocks performed in pediatric patients under general anesthesia.
We evaluated the relationship between the lowest current amperage used to obtain a motor response, the success rate and the incidence of neurological complications with peripheral nerve blocks (PNB) in pediatric patients under general anesthesia. ⋯ In this study, a similar PNB success rate was observed with both a low (*0.5 mA) and a high stimulation threshold (>0.5 mA). Therefore, it may not be necessary to perform needle manipulations to achieve a low stimulation threshold (< or =0.5 mA), as this may increase the risk of intraneural injection.
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Anesthesia and analgesia · Dec 2007
Case ReportsThe use of a laryngeal mask airway after a prolonged suspension laryngoscopy to preserve a vocal cord fat graft.
A 62-yr-old man presented for a microdirect laryngoscopy and vocal cord fat grafting under jet ventilation. After a prolonged laryngoscopy, the patient developed hypercapnea and upper airway obstruction secondary to traumatic epiglottitis. The placement of a laryngeal mask airway provided ventilation and allowed for direct visualization of the patient's inflamed epiglottis without disruption of the patient's fat graft. Because of its placement above the cords and its effectiveness in providing adequate ventilation, we propose intermittent laryngeal mask airway ventilation as a bridge, in lieu of endotracheal intubation, in microdirect laryngoscopy cases in which ventilation during emergence may be difficult and the insertion of an endotracheal tube would disrupt the surgical procedure.
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Anesthesia and analgesia · Dec 2007
Case ReportsEmergent retrograde tracheal intubation with a gum-elastic bougie in a trauma patient.
Patients with severe maxillofacial trauma pose a challenge when their airways must be secured. Often, emergent surgical airways are established when largyngoscopy or fiberoptic intubation are unsuccessful. When an airway cannot be surgically established, the anesthesiologist is forced to use novel approaches to airway management, but there are few descriptions of such techniques in the literature. ⋯ When an uncontrolled airway cannot be secured surgically and a tracheal defect is present, retrograde intubation with a gum-elastic bougie may be considered as an emergent management option.
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Anesthesia and analgesia · Dec 2007
Piezoelectric vibrating needle and catheter for enhancing ultrasound-guided peripheral nerve blocks.
Ultrasound imaging has been used for performing single-injection peripheral nerve blocks and continuous catheters. One limitation with current technology is the inability to confirm the location of the needle or catheter tip. We describe a new needle and catheter design that permits distal tip visualization using color flow Doppler. ⋯ When activated, the tip of each was highlighted in color when scanned in the short axis using the color Doppler mode of a two-dimensional ultrasound and a 12 MHz L38 probe (MicroMaxx, Sonosite, Bothell, WA). Vibration technology may be a useful adjunct while performing ultrasound-guided regional anesthesia. Further study evaluating its usefulness and safety in live tissue is warranted.
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Anesthesia and analgesia · Dec 2007
Comparative StudyThe effects of centrally administered dexmedetomidine on cardiovascular and sympathetic function in conscious rats.
The alpha2-receptor is expressed in the brain, including the hypothalamus, where it is implicated in autonomic nervous system control. The effects of systemic administration of dexmedetomidine (DEX) on cardiovascular responses are well known; however, little is known about the effects of central administration of DEX on cardiovascular responses in conscious animals. In this study, we explored the effects and the mechanism of intracerebroventricularly (icv) administered DEX on cardiovascular responses and sympathetic nerve activity in conscious, unrestrained rats. ⋯ These results indicate that icv administration of DEX decreases MAP by sympathetic inhibition and decreases HR by sympathetic inhibition and vagal stimulation.