Anesthesia and analgesia
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Anesthetic drugs have the potential to contribute to global warming. There is some debate about the overall impact of anesthetic drugs relative to carbon dioxide, but there is no question that practice patterns can limit the degree of environmental contamination. In particular, careful attention to managing fresh gas flow can use anesthetic drugs more efficiently--reducing waste while achieving the same effect on the patient. ⋯ This article provides background information and discusses strategies for managing fresh gas flow during each phase of anesthesia with the goal of reducing waste when using a circle anesthesia system. Monitoring oxygen and anesthetic gas concentrations is essential to implementing these strategies safely and effectively. Future technological advances in anesthetic delivery systems are needed to make it less challenging to manage fresh gas flow.
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Anesthesia and analgesia · May 2012
Randomized Controlled TrialUltrasound-guided popliteal sciatic block with a single injection at the sciatic division results in faster block onset than the classical nerve stimulator technique.
For successful, fast-onset sciatic popliteal block (SPB), either a single injection above the division of the sciatic nerve, or 2 injections to block the tibial nerve (TN) and common peroneal nerve (CPN) separately have been recommended. In this study, we compared the traditional nerve stimulator (NS)-guided SPB above the division of the sciatic nerve with the ultrasound (US)-guided block with single injection of local anesthetic (LA) between the TN and CPN at the level of their division. We hypothesized that US-SPB with a single injection between TN and CPN would result in faster block onset than a single-injection NS-SPB. ⋯ A single injection of LA in US-SPB with needle insertion at the separation of the TN and CPN results in a similar success rate at 30 minutes; however, more patients in the US-SPB group than in the NS-SPB group had complete block at 15 minutes.
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Anesthesia and analgesia · May 2012
ReviewThe current status of continuous noninvasive measurement of total, carboxy, and methemoglobin concentration.
Intraoperative early detection of anemia, identifying toxic levels of carboxyhemoglobin after carbon monoxide exposure and titrating drug dosage to prevent toxic levels of methemoglobin are important goals. The pulse oximeter works by illuminating light into the tissue and sensing the amount of light absorbed. ⋯ Currently there are 2 commercial pulse oximeters (Masimo Rainbow SET and OrSense NBM-200MP) that measure total hemoglobin concentration and one (Masimo) that also measures methemoglobin and carboxyhemoglobin. In this review, we describe the peer-reviewed literature addressing the accuracy of these monitors.