Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2011
Technical communication: An initial evaluation of a novel anesthetic scavenging interface.
Waste anesthetic gas scavenging technology has not changed appreciably in the past 30 years. Open reservoir systems entrain high volumes of room air and dilute waste gases before emission into the atmosphere. This process requires a large vacuum pump, which is both costly to install and, although efficient, operates continuously and at near-full capacity. ⋯ Using the ventilator increased this flow by approximately 6 L/min because of the exhaust of ventilator drive gas into the scavenging circuit. Daytime workload of the central vacuum pump decreased from 92% to 12% (expressed as duty cycle). The new system produces energy savings and may increase vacuum pump lifespan.
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Anesthesia and analgesia · Nov 2011
Case ReportsCase report: Severe vasospasm mimics hypotension after high-dose intrauterine vasopressin.
Intramyometrial vasopressin injection reduces bleeding during myomectomy. Subsequent loss of peripheral pulses and nonmeasurable arterial blood pressure have been attributed to cardiovascular collapse or hypotension. ⋯ We describe a patient who developed loss of peripheral pulses and nonmeasurable blood pressure by noninvasive means after myometrial administration of 60 U vasopressin, with documented severe peripheral arterial vasospasm and elevated proximal blood pressure. We discuss the pathophysiology and emphasize the danger of misinterpreting pulselessness as global hypotension instead of vasospasm in this setting.
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Anesthesia and analgesia · Nov 2011
Pleth variability index to predict fluid responsiveness in colorectal surgery.
Goal-directed fluid therapy during major abdominal surgery may reduce postoperative morbidity. The Pleth Variability Index (PVI), derived from the pulse oximeter waveform, has been shown to be able to predict fluid responsiveness in a number of surgical circumstances. In the present study, we sought to determine whether PVI could predict fluid responsiveness in low-risk colorectal surgery patients who had fluid therapy guided by esophageal Doppler stroke volume measurements. ⋯ PVI measured at the finger may be able to predict fluid responsiveness during surgery in ventilated patients.
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Anesthesia and analgesia · Jan 2011
Comparative StudyCurrent-distance relationships for peripheral nerve stimulation localization.
Successful peripheral nerve blocks require accurate placement of the injection needle tip before local anesthetic application. In this investigation, we experimentally reconstructed polarity-dependent (anode and cathode) stimulation maps using ex vivo and in vivo animal models. ⋯ Cathodic stimulation may produce conduction block at close tip-to-nerve distances. In contrast, anodic stimulation elicited output characteristics that were predictable and more suitable for nerve localization. We believe anodic stimulation is a viable option at near-nerve distances, despite the increased current requirements. This hypothesis is a paradigm shift in stimulation nerve localization, which conventionally has been cathode based. The hypothesis should be clinically validated.