Anesthesia and analgesia
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Anesthesia and analgesia · May 2008
Comparative StudyDo new anesthesia ventilators deliver small tidal volumes accurately during volume-controlled ventilation?
During mechanical ventilation of infants and neonates, small changes in tidal volume may lead to hypo- or hyperventilation, barotrauma, or volutrauma. Partly because breathing circuit compliance and fresh gas flow affect tidal volume delivery by traditional anesthesia ventilators in volume-controlled ventilation (VCV) mode, pressure-controlled ventilation (PCV) using a circle breathing system has become a common approach to minimizing the risk of mechanical ventilation for small patients, although delivered tidal volume is not assured during PCV. A new generation of anesthesia machine ventilators addresses the problems of VCV by adjusting for fresh gas flow and for the compliance of the breathing circuit. In this study, we evaluated the accuracy of new anesthesia ventilators to deliver small tidal volumes. ⋯ Newer generation anesthesia machine ventilators that compensate for breathing circuit compliance and for fresh gas flow are able to deliver small tidal volumes accurately to the airway under conditions of normal and low lung compliance during volume-controlled ventilation. Accurate VCV may be a useful alternative to PCV, as volume is guaranteed when lung compliance changes, and new strategies such as small volume/lung protective ventilation become possible in the operating room.
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Anesthesia and analgesia · May 2008
Randomized Controlled TrialThe prophylactic effect of haloperidol plus dexamethasone on postoperative nausea and vomiting in patients undergoing laparoscopically assisted vaginal hysterectomy.
Haloperidol, a major tranquilizer, has been found to have a potent antiemetic effect on postoperative nausea and vomiting (PONV), but the prophylactic effect of haloperidol plus dexamethasone on PONV has not been evaluated. We evaluated the prophylactic effect of haloperidol plus dexamethasone to either given alone, placebo or droperidol on PONV in patients undergoing a laparoscopic-assisted vaginal hysterectomy. ⋯ Prophylactic haloperidol 2 mg plus dexamethasone 5 mg produced a greater reduction in the incidence of PONV than did either drug used alone, placebo or droperidol without increasing perioperative adverse outcomes.
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Anesthesia and analgesia · May 2008
Comparative StudyEffects of a suction laryngoscope in a model with simulated severe airway hemorrhage.
In severe airway hemorrhage, simultaneous suction and laryngoscopy may render intubation difficult. We built a suction laryngoscope that consists of an adjustable stainless steel-guide tube fixed at the lingual surface of a standard Macintosh laryngoscope blade. Via this steel-guide tube, a large suction catheter can be inserted and positioned exactly to suction pharyngeal blood or vomitus, rendering simultaneous suctioning and laryngoscopy possible. ⋯ To assess whether our suction laryngoscope could provide better intubation conditions in comparison to a standard Macintosh laryngoscope in a bleeding airway scenario, 44 medical students intubated a manikin with severe simulated airway hemorrhage using our suction laryngoscope and a standard Macintosh laryngoscope in random order. There was no significant difference in time needed for intubation when using the suction versus the Macintosh laryngoscope (mean +/- SD: 43 +/- 13 vs 52 +/- 31 s; P = 0.07), but the number of esophageal intubations was significantly lower when using the suction laryngoscope [6 of 44 (13.6%) vs 19 of 44 (43.2%); P = 0.004]. In conclusion, when compared with a standard Macintosh laryngoscope, using a suction laryngoscope did not result in more rapid intubation, but significantly decreased the likelihood of esophageal intubations.
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Anesthesia and analgesia · May 2008
Case ReportsIntravenous lipid infusion in the successful resuscitation of local anesthetic-induced cardiovascular collapse after supraclavicular brachial plexus block.
We describe a case of successful resuscitation with an i.v. lipid infusion of local anesthetic-induced cardiovascular toxicity after supraclavicular brachial plexus block with mepivacaine and bupivacaine. Lipid therapy was initiated after 10 min of unsuccessful resuscitation and resulted in restoration of cardiovascular activity and hemodynamic stability. This case illustrates the utility of i.v. lipid therapy in the treatment of local anesthetic toxicity.
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Anesthesia and analgesia · May 2008
Lidocaine increases intracellular sodium concentration through a Na+-H+ exchanger in an identified Lymnaea neuron.
The intracellular sodium concentration ([Na(+)]in) is related to neuron excitability. For [Na(+)]in, a Na(+)-H(+) exchanger plays an important role, which is affected by intracellular pH ([pH]in). However, the effect of lidocaine on [pH]in and a Na(+)-H(+) exchanger is unclear. We used neuron from Lymnaea stagnalis to determine how lidocaine affects [pH]in, Na(+)-H(+) exchanger, and [Na(+)]in. ⋯ Lidocaine increases the [Na(+)] through a Na(+)-H(+) exchanger by proton trapping.