Regional anesthesia and pain medicine
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Reg Anesth Pain Med · Sep 2014
Randomized Controlled TrialUltrasound-Guided Continuous Interscalene Block: The Influence of Local Anesthetic Background Delivery Method on Postoperative Analgesia After Shoulder Surgery: A Randomized Trial.
Automated bolus delivery has recently been shown to reduce local anesthetic consumption and improve analgesia, compared with continuous infusion, in continuous sciatic and epidural block. However, there are few data on the influence of local anesthetic delivery method on local anesthetic consumption following interscalene blockade. This randomized, double-blind trial was designed to determine whether hourly automated perineural boluses (4 mL) of local anesthesia delivered with patient-controlled pro re nata (PRN, on demand) boluses would result in a reduction in total local anesthesia consumption during continuous interscalene blockade after shoulder surgery compared with continuous perineural infusion (4 mL/h) plus patient-controlled PRN boluses. ⋯ In continuous interscalene blockade under ultrasound guidance after shoulder surgery, automated boluses of local anesthetic combined with PRN boluses did not provide any reduction in local anesthetic consumption or rescue analgesia, compared with continuous infusion combined with PRN boluses.
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Reg Anesth Pain Med · Sep 2014
Intraneural or Extraneural: Diagnostic Accuracy of Ultrasound Assessment for Localizing Low-Volume Injection.
When one is performing ultrasound-guided peripheral nerve blocks, it is common to inject a small amount of fluid to confirm correct placement of the needle tip. If an intraneural needle tip position is detected, the needle can then be repositioned to prevent injection of a large amount of local anesthetic into the nerve. However, it is unknown if anesthesiologists can accurately discriminate intraneural and extraneural injection of small volumes. Therefore, this study was conducted to determine the diagnostic accuracy of ultrasound assessment using a criterion standard and to compare experts and novices in ultrasound-guided regional anesthesia. ⋯ Discrimination of intraneural or extraneural needle tip position based on an injection of 0.5mL is possible, but even experts missed 1 of 6 intraneural injections. In novices, the sensitivity of assessment was significantly lower, highlighting the need for focused education.
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Reg Anesth Pain Med · Sep 2014
Case ReportsFentanyl Overdose Caused by Malfunction of SynchroMed II Intrathecal Pump: Two Case Reports.
Intrathecal drug delivery systems (intrathecal pumps) are used to treat patients with chronic refractory pain syndromes and spasticity. The objective of our case report was to demonstrate that intrathecal pump malfunction can lead to intrathecal overdosing of drugs. ⋯ We present 2 cases of intrathecal pump malfunction, which most likely led to overinfusion of fentanyl intrathecally. To reduce the risk of this complication, particular attention should be paid to drug reservoir volume discrepancies and overdose symptoms reported by patients.