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
Comparative StudyInhibition of the cyclic adenosine monophosphate pathway attenuates neuropathic pain and reduces phosphorylation of cyclic adenosine monophosphate response element-binding in the spinal cord after partial sciatic nerve ligation in rats.
Recent reports have identified a role for cyclic adenosine monophosphate (cAMP) transduction in nociceptive processing. Spinal activation of the cAMP induced gene transcription through the activation of protein kinase A and cAMP response element-binding protein (CREB). Intrathecal injection of protein kinase A inhibitor reversed the mechanical hyperalgesia, whereas injection of CREB antisense attenuated tactile allodynia caused by partial sciatic nerve ligation (PSNL) in rats. In the present study, we aimed to assess the effects of spinal cAMP transduction on the nociceptive processing in a chronic neuropathic pain model. ⋯ These results revealed the possible contribution of an increase in pCREB to the PSNL-induced tactile allodynia and thermal hyperalgesia. Modulation of the cAMP pathway may be clinically relevant if early intervention can be achieved in patients with chronic neuropathic pain.
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Anesthesia and analgesia · Dec 2007
Estimation of optimal modeling weights for a Bayesian-based closed-loop system for propofol administration using the bispectral index as a controlled variable: a simulation study.
Implementing Bayesian methods in a model-based closed-loop system requires the integration of a standard response model with a patient-specific response model. This process makes use of specific modeling weights, called Bayesian variances, which determine how the specific model can deviate from the standard model. In this study we applied simulations to select the Bayesian variances yielding the optimal controller for a Bayesian-based closed-loop system for propofol administration using the Bispectral Index (BIS) as a controlled variable. ⋯ We believe this system can be introduced safely into clinical testing for both induction and maintenance of anesthesia under direct observation of an anesthesiologist.
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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.