Anesthesia and analgesia
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Anesthesia and analgesia · Jun 2004
A platelet activating factor receptor antagonist inhibits cytokine production in human whole blood by bacterial toxins and live bacteria.
We previously reported that a platelet-activating factor receptor (PAFR) antagonist (TCV-309) suppressed lipopolysaccharide (LPS)-induced mortality and tumor necrosis factor (TNF) production in mice. However, the effect of TCV-309 on cytokine production induced by Staphylococcus enterotoxin B (SEB) or live bacteria has not been reported. In this study we investigated the effect of TCV-309 on cytokine production in human whole blood induced by LPS, SEB, and both Gram-positive and -negative bacteria. Human whole blood diluted 5:1 (980 microL) was placed in the wells of a 24-well plate. Ten microliters of LPS, SEB, Escherichia coli O18 K(+), or Staphylococcus aureus were added to each well. After incubation at 37 degrees C for 6 h, TNF, interleukin (IL)-6, and IL-8 in the culture medium were measured. TCV-309 did not affect the growth of either E. coli or S. aureus bacteria in the culture medium for the 6 h incubation. LPS, SEB, and both E. coli and S. aureus induced TNF, IL-6, and IL-8 in human whole blood. TCV-309 significantly inhibited the production of TNF, IL-6, and IL-8 induced by LPS, SEB, and bacteria. A PAFR antagonist suppressed cytokine production induced by LPS, SEB, and both Gram-positive and -negative bacteria in human whole blood. A PAFR plays an important role of producing proinflammatory cytokines induced by both toxins and live bacteria. ⋯ The platelet-activating factor receptor plays an important role in producing proinflammatory cytokines induced by bacterial toxins, such as lipopolysaccharide,Staphylococcus enterotoxin B, and live Gram-positive and Gram-negative bacteria.
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Anesthesia and analgesia · Jun 2004
Simultaneous determination of neuromuscular blockade at the adducting and abducting laryngeal muscles using phonomyography.
Phonomyography (PMG) is a new method for measuring neuromuscular blockade (NMB) at the larynx. In this study, we used PMG to compare NMB at the posterior cricoarytenoid (PCA) and the lateral cricoarytenoid muscle (LCA) in humans. Twelve patients were included in this study. Endotracheal intubation was performed without aid of neuromuscular blocking drugs. One small condenser microphone was inserted beside the vocal cords into the muscular process at the base of the arytenoid cartilage to record acoustic responses of the LCA (vocal cord adduction), and a second microphone was placed behind the larynx to measure NMB of the PCA (vocal cord abduction). Stimulation of the recurrent laryngeal nerve was performed using superficial electrodes placed at the neck (midline between jugular notch and cricoid cartilage) using train-of-four (TOF) stimulation every 12 s. After supramaximal stimulation, mivacurium 0.1 mg/kg was injected and onset, peak effect, and offset of NMB measured and compared using t-test (P < 0.05). The data are presented as mean (SD). Peak effect, onset time, and early recovery to 25% of control twitch height were not significantly different between PCA and LCA at 86% (13) versus 78% (16), 2.3 min (0.45) versus 2.3 min (1.0), and 9.55 min (3.05) versus 8.5 min (4.7), respectively. However, recovery to 75%, 90% of control twitch height, and recovery to a TOF ratio of 0.8 were significantly longer at the PCA than at the LCA at 14 min (4) versus 11 min (5), 17 min (5) versus 11.8 min (5.6), and 17.5 min (5.6) versus 12.3 min (5.5), respectively. The authors conclude that recovery of NMB at the PCA takes longer than at the LCA in humans after mivacurium. ⋯ After neuromuscular blockade in humans, the recovery of the ability to open the vocal cords takes longer than the ability to close the vocal cords.
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Anesthesia and analgesia · Jun 2004
Bispectral index during isoflurane anesthesia in pediatric patients.
Bispectral index (BIS) was developed to monitor anesthetic depth in adults, but has been investigated for use in children, using sevoflurane. We examined the concentration-response relationship between BIS and isoflurane. Thirty children undergoing cardiac catheterization received continuous intraoperative BIS monitoring and had BIS values recorded at 6 steady-state end-tidal isoflurane (Et(Iso)) concentrations between 1.5% and 0.5% and at first arousal. The mean (SD) values for BIS were as follows: 1.5%, 32.3 +/- 11.7; 1.3%, 34.7 +/- 12.5; 1.1%, 40.5 +/- 13.3; 0.9%, 48.0 +/- 13.7; 0.7%, 55.9 +/- 14.4; and 0.5%, 61.8 +/- 13.1. There was an inverse correlation between Et(Iso) and BIS (r = -0.634; P < 0.01). There were significant differences (P < 0.0001) in mean BIS values between adjacent Et(Iso) in all cases except 1.5% versus 1.3%. An inhibitory sigmoid E(max) model best described the BIS-isoflurane concentration relationship, with an 50% effective dose of 0.85% (95% confidence interval, 0.72%-0.98%). The mean value of BIS at first arousal was 78.5 +/- 12.3. The relationship between Et(Iso) and BIS is qualitatively and quantitatively similar to that described for isoflurane in adults and sevoflurane in children. These results add to the body of evidence that BIS is adequately calibrated for use in children older than 1 yr. ⋯ This observational study of children undergoing cardiac catheterization characterizes the concentration-response relationship between bispectral index and isoflurane and demonstrates that bispectral index seems adequately calibrated for monitoring the depth of isoflurane anesthesia in pediatric patients.
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Anesthesia and analgesia · Jun 2004
Intraosseous vascular access in the treatment of chemical warfare casualties assessed by advanced simulation: proposed alteration of treatment protocol.
Current treatment protocols for chemical warfare casualties assume no IV access during the early treatment stages. Time constraints in mass casualty scenarios, impaired manual dexterity of medical personnel wearing protective gear, and victims' complex clinical presentations render standard IV access techniques impractical. A newly developed spring-driven, trigger-operated intraosseous infusion device may offer an effective solution. Sophisticated simulators were developed and used to mimic scenarios of chemical warfare casualties for assessing the feasibility of intraosseous infusion delivery. We evaluated the clinical performance of medical teams in full protective gear. The success rate in intraosseous insertion, time to completion of treatment goals, and outcome were measured in a simulated setting. Medical teams from major hospitals in Israel, designated for emergency response in a real chemical warfare mass casualty scenario, were trained in a simulated setting. All 94 participating physicians were supplied with conventional treatment modalities: only the 64 study group physicians received intraosseous devices. The simulated survival rate was 73.4% for the study group and 3.3% for the controls (P < 0.001). Treatment goals were achieved within 3.5 min (range, 1-9 min) in the study group and within >10 min for controls (P < 0.001), and the complication rate for intraosseous use was 13.8%. Personnel satisfaction with the intraosseous device was unanimous and high. New-generation intraosseous infusions have great potential value in the early treatment stages of chemical warfare casualties. ⋯ In a chemical warfare mass casualty scenario, the protective gear worn by medical personnel, the time constraints, and the casualties' medical condition impose limitations on the establishment of IV access during early treatment of the victims. A spring-driven, trigger-operated intraosseous infusion delivery system may offer an effective solution.
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Anesthesia and analgesia · Jun 2004
Case ReportsIntracranial hypotension caused by cervical cerebrospinal fluid leak: treatment with epidural blood patch.
This report describes treatment with cervical epidural blood patch of low cerebrospinal fluid (CSF) pressure headache resulting from spontaneous CSF leak via a tear in a cervical dural cuff. The leak was diagnosed by a dynamic computed tomography (CT)-myelography study followed by gadolinium enhanced magnetic resonance imaging(MRI)-scan. The epidural needle was inserted with the aid of image intensifier and CT-scan to guide the needle to the precise site of the CSF leak. Blood mixed with gadolinium was injected, and subsequent MRI scanning provided the first description of spread of blood after cervical epidural blood patch. ⋯ Low cerebrospinal fluid (CSF) pressure may cause severe posturally-related headache. In the patient, a vertebral disc protrusion in the neck seems to have contributed to a CSF leak. An injection of blood into the epidural space at the precise site of the CSF leak was followed by complete and lasting resolution of the headache.