Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Mar 2008
Reduced injection pressures using a compressed air injection technique (CAIT): an in vitro study.
High injection pressures have been associated with intraneural injection and persistent neurological injury in animals. Our objective was to test whether a reported simple compressed air injection technique (CAIT) would limit the generation of injection pressures to below a suggested 1,034 mm Hg limit in an in vitro model. ⋯ This study demonstrated that CAIT can effectively keep injection pressures under 1,034 mm Hg in this in vitro model. Animal and clinical studies will be needed to determine whether CAIT will allow objective, real-time pressure monitoring. If high pressure injections are proven to contribute to nerve injury in humans, this technique may have the potential to improve the safety of peripheral nerve blocks.
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Reg Anesth Pain Med · Mar 2008
Comparative StudyIsobolographic analysis of epinephrine with bupivacaine, dextromethorphan, 3-methoxymorphinan, or dextrorphan on infiltrative anesthesia in rats: dose-response studies.
The aims of this study were to establish the potencies of epinephrine, bupivacaine, dextromethorphan, 3-methoxymorphinan, and dextrorphan and evaluate interactions of epinephrine with bupivacaine, dextromethorphan, 3-methoxymorphinan, or dextrorphan as an infiltrative anesthetic. Bupivacaine, a common and long-acting local anesthetic, was used as control. ⋯ Epinephrine, dextromethorphan, 3-methoxymorphinan, and dextrorphan are known to have local anesthetic effects as infiltrative cutaneous analgesia in rats. Epinephrine increased the potency of bupivacaine, but not dextromethorphan, 3-methoxymorphinan, or dextrorphan as an infiltrative anesthetic. The cutaneous analgesic effects of adding epinephrine to dextromethorphan, 3-methoxymorphinan, or dextrorphan, are similar to combinations of 2 local anesthetics.
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Reg Anesth Pain Med · Mar 2008
ReviewClonidine as an adjuvant to intrathecal local anesthetics for surgery: systematic review of randomized trials.
Clonidine is added to intrathecal local anesthetics to improve intraoperative analgesia and to increase the duration of sensory and motor block. The aim of this systematic review is to quantify beneficial and harmful effects of clonidine when used as an adjuvant to intrathecal local anesthetics for surgery. ⋯ This study may serve as a rational basis to help clinicians decide whether or not to combine clonidine with an intrathecal local anesthetic for surgery. The optimal dose of clonidine, however, remains unknown.
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Reg Anesth Pain Med · Mar 2008
ReviewPatient-controlled drug delivery for acute postoperative pain management: a review of current and emerging technologies.
Postoperative pain management has dramatically improved with the advent of patient-controlled analgesia (PCA) delivery. The optimal PCA system would encompass several key characteristics, including consistent efficacy across a number of surgeries; safety of both the analgesic drug delivered and the delivery system; ease of setup, maintenance, and administration; patient comfort during analgesic delivery; avoidance of analgesic gaps; minimal invasiveness; and it would be associated with high patient satisfaction. Existing PCA modalities (using intravenous or epidural routes) encompass some of these characteristics (e.g., they have demonstrated efficacy across a number of surgeries); however, they are limited by the need for an indwelling catheter and the time and resources required for system setup and use. ⋯ New PCA technologies are on the horizon that address some of the limitations to existing modalities; however, the added complexity of these newer systems are a concern, and their benefits and drawbacks remain to be assessed. These technologies include "smart" intravenous PCA infusion pumps to improve the safety of analgesic administration; needle-free options, such as the fentanyl HCl iontophoretic transdermal system for transdermal delivery; and a number of PCA devices for intranasal delivery, as well as several new options for patient-controlled regional analgesia. This review will discuss the benefits and drawbacks of both existing and emerging PCA modalities in the context of the ideal PCA system, and provide a critical evaluation of their use in postoperative settings.
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Reg Anesth Pain Med · Mar 2008
Case ReportsA new approach to preanesthetic site verification after 2 cases of wrong site peripheral nerve blocks.
We discuss the importance of a "preanesthetic site verification" and highlight 2 significant modifications to a policy developed at our institution in 2003. ⋯ The "preanesthetic site verification" is an integral part of preventing wrong site block and surgery. To ensure that it is carried out before every peripheral nerve block, a unique multidisciplinary approach was adopted in which the block needles were removed from anesthesia carts and transferred to a separate container in the area of the circulating nurse. The anesthesiologist must now request a block needle from the circulating nurse immediately prior to block performance and confirm the site at that time. This safety process emulates the presurgical site verification that takes place before a scalpel is passed to a surgeon. Furthermore, the circulating nurse must remain at the bedside until block initiation to make sure that delays between site verification and block performance do not impinge on correct site placement.