Anesthesia and analgesia
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Anesthesia and analgesia · May 2013
Train-of-four and tetanic fade are not always a prejunctional phenomenon as evaluated by toxins having highly specific pre- and postjunctional actions.
Nerve-stimulated fade in muscle is generally accepted as a prejunctional phenomenon mediated by block of prejunctional acetylcholine receptors (AChRs) at the nerve terminal, whereas decrease of twitch tension is considered a postjunctional effect due to block of muscle AChRs. Using ligands with specific pre- or postjunctional effects only, we tested the hypothesis that fade is not necessarily a prejunctional phenomenon. ⋯ Botx-induced decreased ACh release in and of itself does not cause fade but does cause decrease of absolute tensions. Decrease of available (functional) postjunctional AChRs by α-BTX did induce fade. The prejunctional fade effects of DHβE on α3β2 AChRs become manifest only when the margin of safety was decreased by concomitant administration of α-BTX. Thus, fade during repetitive stimulation is not always a prejunctional phenomenon and may also reflect the decreased margin of safety of neurotransmission, which can be due to a pure postjunctional AChRs block or to a combination of both pre- and postjunctional AChRs block. Block of prejunctional α3β2 AChRs alone is not necessary and sufficient to cause fade.
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Anesthesia and analgesia · May 2013
Review Meta AnalysisPreventive analgesia by local anesthetics: the reduction of postoperative pain by peripheral nerve blocks and intravenous drugs.
Barreveld et al. show that LA administered either IV or via block; before, during or after surgery, significantly reduces postoperative pain and opioid consumption.
Specifically in:
- Total knee arthroplasty (femoral, sciatic and lumbar plexus b., single-shot or continuous)
- Total hip arthroplasty (continuous lumbar plexus; intra-articular LA)
- Knee arthroscopy (single-shot lumbar plexus; IA LA; single-shot femoral nerve ± sciatic).
- Arthroscopic shoulder surgery - interscalene b., single-shot or continuous. IA is not beneficial.
- Hand & forearm surgery - axillary b. offers analgesic benefits only on day of surgery.
- TAP block is beneficial for laparoscopic, open appendectomy, abdominal surgery, cesarean section, and TAH.
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Anesthesia and analgesia · May 2013
Randomized Controlled Trial Multicenter StudyNitrous oxide and serious morbidity and mortality in the POISE trial.
Nitrous oxide exposure was not associated with 30-day MI, stroke, death or hypotension in an observational analysis of POISE subjects.
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Anesthesia and analgesia · May 2013
Randomized Controlled TrialAn alternative distal approach for the lumbar medial branch radiofrequency denervation: a prospective randomized comparative study.
An alternative technique involving a "distal approach" can be used for lumbar medial branch radiofrequency denervation (LMBRFD). We described and assessed this technique by comparing it with a conventional tunnel vision approach in a prospective randomized trial. ⋯ Patients who underwent LMBRFD by the tunnel vision or distal approaches showed significant pain relief at the 6-month follow-up. Less periprocedural pain was reported in the distal approach group. We consider that the distal approach provides an improved option for LMBRFD.
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Anesthesia and analgesia · May 2013
Randomized Controlled TrialThe VeinViewer vascular imaging system worsens first-attempt cannulation rate for experienced nurses in infants and children with anticipated difficult intravenous access.
The VeinViewer (Luminetx, Memphis, TN) helps identify veins by projecting an image of subcutaneous vasculature on the skin surface. We tested the primary hypothesis that VeinViewer use improves cannulation success by skilled nurses in pediatric patients with anticipated difficult IV access. A secondary goal was to evaluate the relationship between obesity and cannulation success. ⋯ The VeinViewer worsened first-attempt IV insertion success by skilled nurses. Surprisingly, first-attempt success for IV cannulation was not worsened by obesity.