Anesthesia and analgesia
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Anesthesia and analgesia · Nov 2004
Brand and size matter when choosing a syringe to relieve pressure in a tracheal tube cuff.
We studied the use of an inline syringe as a pressure relief valve for tracheal tube cuffs during exposure to nitrous oxide to see if the technique works. Bench testing was done to determine the stick and slip characteristics of syringes of different brands and sizes. Cuffs were inflated with 20 mL of air, producing a cuff pressure of 100-120 mm Hg. ⋯ We conclude that a syringe attached to the pilot balloon connector can be used to control tracheal tube cuff pressure during nitrous oxide anesthesia. However, not all syringes are suitable for this purpose: large syringes are better than small syringes, and the Terumo brand is more suitable than BD or Monoject. The system does not work automatically, and intermittent compression of the syringe plunger to overcome static friction is required to avoid overdistension.
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Anesthesia and analgesia · Nov 2004
Small-dose capsaicin reduces systemic inflammatory responses in septic rats.
We investigated the influence of small- and large-dose capsaicin in modulating systemic inflammatory responses during different stages of sepsis in rats. Rats were divided into six groups: group C, control; group S, sepsis; group CLC, small dose of capsaicin (1 mg/kg subcutaneously); group SLC, small dose of capsaicin plus sepsis; group CHC, large dose of capsaicin (150 mg/kg subcutaneously); group SHC, large dose of capsaicin plus sepsis. Rats were made septic by cecal ligation and puncture (CLP). ⋯ CGRP was increased in groups S, CLC, and SLC when compared with the other groups. In the SLC group, plasma concentrations of TNF-alpha, IL-6, NOx, and tissue MDA levels were reduced and IL-10 level was increased when compared with groups S and SHC 18 h after CLP (P < 0.05). Small-dose capsaicin treatment increased antiinflammatory IL-10 levels and attenuated the increases in proinflammatory cytokines, NOx, and tissue MDA in septic rats.
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Anesthesia and analgesia · Nov 2004
Impaired acquisition of spatial memory 2 weeks after isoflurane and isoflurane-nitrous oxide anesthesia in aged rats.
Aged rats are impaired on a spatial memory task for at least 24-48 h after isoflurane-nitrous oxide anesthesia. In this study, we tested how long the impairment lasts and investigated the role of nitrous oxide. Eighteen-month-old rats were randomized to anesthesia for 2 h with 1.2% isoflurane with or without 70% nitrous oxide or a control group (30% oxygen). ⋯ Post hoc analysis comparing all anesthetized rats to controls demonstrated that anesthetized rats made fewer correct choices to first error (P < or = 0.05) and took longer to complete the maze (P
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Anesthesia and analgesia · Nov 2004
Characterization of a new animal model for evaluation of persistent postthoracotomy pain.
Chronic pain after thoracotomy is common, although its basis and therapy have not been well characterized. In this study we characterize the allodynic responses (mechanical and cold) as well as the histopathologic changes after thoracotomy and rib retraction in rats. The antinociceptive effect of systemic and intrathecal analgesics was also evaluated. ⋯ Systemic morphine sulfate (50% effective dose [ED(50)], 1.06 mg/kg) and gabapentin (ED(50), 24.2 mg/kg), as well as intrathecal morphine (ED(50), 1.19 nmol), gabapentin (ED(50), 13.8 nmol), clonidine (ED(50), 72.7 nmol), and neostigmine (ED(50), 0.54 nmol) reduced allodynia. Rib-retraction in rats for 60 min produces allodynia that lasts more than 1 mo, and this allodynia is reduced by morphine, gabapentin, clonidine, and neostigmine. This new model may be useful for quantifying the efficacy of techniques to reduce the frequency and severity of long-term postthoracotomy pain.