bluuebunny/crossref_metadata_2025_split huggingface dataset:
Local Anesthetics Impair Human Granulocyte Phagocytosis Activity, Oxidative Burst, and CD11b Expression in Response to Staphylococcus aureus
Authors: Kiefer Ralph-Thomas , Ploppa Annette , Krueger Wolfgang A. , Plank Michael , Nohé Boris , Haeberle Helene A. , Unertl Klaus , Dieterich Hans-Jürgen 
Published: November 2003

Background
With invasion of bacteria, the host defense system is activated by a complex cascade of various mechanisms. Local anesthetics previously were shown to interact with diverse components of the immune response, such as leukocyte adherence on endothelial monolayers, oxidative burst, or crosstalk within lymphocyte subset populations. However, effects of newer local anesthetics like bupivacaine and ropivacaine on antibacterial host defense-primarily phagocytosis activity, oxidative burst, or CD11b expression-still remain unclear.

Methods
Whole blood samples were preincubated with local anesthetics (lidocaine, 9.2, 92.2, and 1,846 microm bupivacaine, 6.1, 61, and 770 microm; ropivacaine, 6.4, 64, and 801 microm). For the oxidative burst and CD11b assay, dihydroethidium was added to the probes. After viable Staphylococcus aureus was added in a 5 to 1 ratio following leukocyte count, phagocytosis was stopped at different times, and staining with monoclonal antibodies was performed for subsequent flow cytometric analysis of phagocytosis activity, oxidative burst, and CD11b expression.

Results
Granulocyte phagocytosis activity, CD11b expression, and generation of reactive oxygen species were significantly reduced by lidocaine (P < 0.0002) and bupivacaine (P < 0.005) in the highest concentration (1,846 microm and 770 microm, respectively). The capability of granulocytes to ingest bacteria was significantly depressed only by lidocaine (P < 0.003). Ropivacaine had no significant effect on any parameter investigated.

Conclusions
Local anesthetic dose and structure dependently inhibit inflammatory and immunologic parameters of granulocyte functions. Ropivacaine shows low interference with granulocyte immunologic and inflammatory functions.
Impact of Bispectral Index Monitoring on Fast Tracking of Gynecologic Patients Undergoing Laparoscopic Surgery
Authors: Ahmad Shireen , Yilmaz Meltem , Marcus R-Jay , Glisson Silas , Kinsella Annette 
Published: November 2003

Background
The need for increasing operating room efficiency has led to various initiatives, one of which is the elimination of mandatory admission to the phase I recovery area postoperatively, also referred to as fast tracking of ambulatory surgery patients. This Institutional Review Board-approved study was conducted to evaluate the effect of Bispectral Index (BIS) monitoring on the ability of patients to successfully bypass the phase I recovery area following gynecologic laparoscopy during general anesthesia.

Methods
Ninety-nine consenting patients were randomly assigned to one of two groups: group one, in which the BIS monitor (Aspect Medical Systems, Natick, MA) was used, and group two, in which no BIS monitor was used. All patients received a standardized anesthetic that included 1 microg/kg sufentanil and sevoflurane in oxygen, titrated in group one to a BIS value of 50-60 and in group two to maintain vital signs within 20% of preoperative values. All patients received prophylactic nonsteroidal antiinflammatory drugs and antiemetics. Postoperatively, patients were evaluated using the modified Aldrete scoring system, and those who achieved a score of 9 or higher within 10 min were permitted to bypass the phase I recovery area.

Results
There was no statistically significant difference between the two groups with respect to the number of patients who successfully bypassed the phase I recovery area, postoperative length of hospital stay, or cost of hospitalization.

Conclusion
With a standardized anesthetic regimen and a strict discharge scoring system, BIS monitoring does not have a significant effect on the ability to fast track outpatients.
Dual Effects of Hexanol and Halothane on the Regulation of Calcium Sensitivity in Airway Smooth Muscle
Authors: Yoshimura Hayashi , Jones Keith A. , Perkins William J. , Warner David O. 
Published: November 2003

Background
Contraction of airway smooth muscle is regulated by receptor-coupled mechanisms that control the force developed for a given cytosolic calcium concentration (i.e., calcium sensitivity). Halothane antagonizes acetylcholine-induced increases in calcium sensitivity by inhibiting GTP-binding (G)-protein pathways. The authors tested the hypothesis that hexanol, like halothane, inhibits agonist-induced increases in calcium sensitivity in airway smooth muscle by inhibiting G-protein pathways.

Methods
Calcium sensitivity was assessed using alpha-toxin-permeabilized canine tracheal smooth muscle. In selected experiments, regulatory myosin light chain phosphorylation was also determined by Western blotting in the presence and absence of 10 mm hexanol and/or 100 microm acetylcholine.

Results
Hexanol (10 mm) and halothane (0.76 mm) attenuated acetylcholine-induced calcium sensitization by decreasing regulatory myosin light chain phosphorylation during receptor stimulation. Hexanol also inhibited increases in calcium sensitivity due to direct stimulation of heterotrimeric G-proteins with tetrafluoroaluminate but not with 3 microm GTPgammaS, consistent with prior results obtained with halothane. In contrast, in the absence of receptor stimulation, both compounds produced a small increase in calcium sensitivity by a G-protein-mediated increase in regulatory myosin light chain phosphorylation that was not affected by pertussis toxin treatment.

Conclusions
The authors noted dual effects of hexanol and halothane. In the presence of muscarinic receptor stimulation, hexanol, like halothane, decreases calcium sensitivity by interfering with heterotrimeric G-protein function. However, in the absence of muscarinic receptor stimulation, hexanol and halothane slightly increase calcium sensitivity by a G-protein-mediated process not sensitive to pertussis toxin. Hexanol may represent a useful experimental tool to study the effect of anesthetics on heterotrimeric G-protein function.
A Mechanism for Rapacuronium-induced Bronchospasm
Authors: Jooste Edmund , Klafter Farrah , Hirshman Carol A. , Emala Charles W. 
Published: November 2003

Background
A safe and effective ultra-short-acting nondepolarizing neuromuscular blocking agent is required to block nicotinic receptors to facilitate intubation. Rapacuronium, which sought to fulfill these criteria, was withdrawn from clinical use due to a high incidence of bronchospasm resulting in death. Understanding the mechanism by which rapacuronium induces fatal bronchospasm is imperative so that newly synthesized neuromuscular blocking agents that share this mechanism will not be introduced clinically. Selective inhibition of M2 muscarinic receptors by muscle relaxants during periods of parasympathetic nerve stimulation (e.g., intubation) can result in the massive release of acetylcholine to act on unopposed M3 muscarinic receptors in airway smooth muscle, thereby facilitating bronchoconstriction.

Methods
Competitive radioligand binding determined the binding affinities of rapacuronium, vecuronium, cisatracurium, methoctramine (selective M2 antagonist), and 4-diphenylacetoxy-N-methylpiperidine methiodide (4-DAMP; selective M3 antagonist) for M2 and M3 muscarinic receptors.

Results
Rapacuronium competitively displaced 3H-QNB from the M2 muscarinic receptors but not from the M3 muscarinic receptors within clinically relevant concentrations. Fifty percent inhibitory concentrations (mean +/- SE) for rapacuronium were as follows: M2 muscarinic receptor, 5.10 +/- 1.5 microm (n = 6); M3 muscarinic receptor, 77.9 +/- 11 microm (n = 8). Cisatracurium and vecuronium competitively displaced 3H-QNB from both M2 and M3 muscarinic receptors but had affinities at greater than clinically achieved concentrations for these relaxants.

Conclusions
Rapacuronium in clinically significant doses has a higher affinity for M2 muscarinic receptors as compared with M3 muscarinic receptors. A potential mechanism by which rapacuronium may potentiate bronchoconstriction is by blockade of M2 muscarinic receptors on prejunctional parasympathetic nerves, leading to increased release of acetylcholine and thereby resulting in M3 muscarinic receptor-mediated airway smooth muscle constriction.
Parecoxib Sodium, a Parenteral Cyclooxygenase 2 Selective Inhibitor, Improves Morphine Analgesia and Is Opioid-sparing following Total Hip Arthroplasty
Authors: Malan T. Philip , Marsh Gregory , Hakki Sam I. , Grossman Evie , Traylor Louise , Hubbard Richard C. 
Published: November 2003

Background
This study examined the opioid-sparing effectiveness, analgesic efficacy, and tolerability of postoperative administration of the parenteral cyclooxygenase 2 selective inhibitor, parecoxib sodium, in total hip arthroplasty patients.

Methods
This was a multicenter, multiple-dose, randomized, double-blind, placebo-controlled study to compare the opioid-sparing effects, analgesic efficacy, and tolerability of postoperative 20 and 40 mg intravenous parecoxib sodium with placebo in hip arthroplasty patients. The first dose of study medication was administered after surgery with an intravenous bolus dose of 4 mg morphine when patients first requested pain medication; remedication with the study medication occurred at 12 and 24 h. Subsequent morphine doses (1-2 mg) were administered by patient-controlled analgesia. Efficacy was assessed by total morphine used, pain relief and pain intensity, time to last dose of morphine, and Global Evaluation rating of the study medication.

Results
Parecoxib sodium, 20 and 40 mg, reduced the total amount of morphine required over 36 h by 22.1% (56.5 mg morphine) and 40.5% (43.1 mg morphine), respectively, compared with placebo (72.5 mg morphine; P < 0.01). Patients receiving 20 and 40 mg parecoxib sodium experienced significantly greater maximum pain relief compared with those in the placebo group (P < 0.05). Patients who received 20 and 40 mg parecoxib sodium discontinued PCA morphine earlier than patients receiving placebo and had significantly higher Global Evaluation ratings. Parecoxib sodium, 40 mg, plus morphine demonstrated a significantly lower incidence of fever and vomiting compared with placebo plus morphine.

Conclusions
Administration of parecoxib sodium with PCA morphine resulted in significantly improved postoperative analgesic management as defined by reduction in opioid requirement, lower pain scores, reduced time on PCA morphine, and higher Global Evaluation ratings.
Local Anesthetic Requirements Are Greater in Dystocia Than in Normal Labor
Authors: Panni Moeen K. , Segal Scott 
Published: November 2003

Background
Dystocia is characterized by abnormal progress of labor and is a common contemporary indication for cesarean delivery in the United States. There has been considerable controversy as to whether epidural analgesia causes dysfunctional labor leading to cesarean delivery for dystocia. The minimum local analgesic concentration (MLAC) is a clinical model used to determine the relative potencies of local anesthetics in the first stage of labor. In this article, the authors report a prospective study determining the MLAC of bupivacaine in early labor of parturients who eventually delivered either vaginally or via cesarean section.

Methods
An up-down sequential allocation technique was used to determine the MLAC of bupivacaine in 57 nulliparous parturients assigned to either vaginal delivery or cesarean section arms. In addition, patients were assigned to groups receiving or not receiving intravenous oxytocin at the time of epidural placement. Only patients who delivered by the assigned delivery mode were included in the MLAC analyses.

Results
Parturients who later delivered vaginally had 25% and 31% lower MLAC values (0.078% and 0.085% wt/vol bupivacaine, receiving or not receiving intravenous oxytocin, respectively) than those who later delivered by cesarean section (0.102% and 0.106% wt/vol bupivacaine, receiving or not receiving intravenous oxytocin, respectively).

Conclusions
These data suggest that an increased local anesthetic requirement for epidural labor analgesia is associated with more intense pain related to dystocia. Women in early, clinically normal labor but who later develop dystocia require more local anesthetic and, by inference, are experiencing more severe pain than women who deliver vaginally. This association should be considered when studying the relation between the method of labor analgesia and the course of labor.
Sub-Tenon Anesthesia
Authors: Guise Philip A. 
Published: November 2003

Background
An initial pilot study of 300 sub-Tenon local anesthetic blocks (STBs) for intraocular surgery established the effectiveness and patient acceptability of the technique. Following this, a decision was made in 1995 to change from sharp needle techniques to STB for all eye surgeries performed during local anesthesia at Auckland Hospital (Auckland, New Zealand) by reeducation of anesthetists and surgeons. At this point, sufficient data were not available to confirm that STB would avoid the complications associated with the passage of sharp needles into the orbit or would cause a different set of serious complications.

Methods
A prospective study of the next 6,000 consecutive STBs performed at Auckland Hospital was carried out over a period of 6 yr (from 1995 to 2000).

Results
Sub-Tenon block is very effective, with a surgeon and patient acceptability rate of 98.8%. Insertion of the sub-Tenon cannula and administration of the anesthetic produces minimal discomfort, being completely painless in 68.8% of cases. There were no serious block-related complications in this series, supporting the safety of the sub-Tenon technique.

Conclusion
The experience at Auckland Hospital provides further support for the avoidance of passing sharp needles into the orbit.
Residual Paralysis in the PACU after a Single Intubating Dose of Nondepolarizing Muscle Relaxant with an Intermediate Duration of Action
Authors: Debaene Bertrand , Plaud Benoît , Dilly Marie-Pierre , Donati François 
Published: November 2003

Background
Residual neuromuscular blockade remains a problem even after short surgical procedures. The train-of-four (TOF) ratio at the adductor pollicis required to avoid residual paralysis is now considered to be at least 0.9. The incidence of residual paralysis using this new threshold is not known, especially after a single intubating dose of intermediate-duration nondepolarizing relaxant. Therefore, the aim of the study was to determine the incidence of residual paralysis in the postanesthesia care unit after a single intubating dose of twice the ED(95) of a nondepolarizing muscle relaxant with an intermediate duration of action.

Methods
Five hundred twenty-six patients were enrolled. They received a single dose of vecuronium, rocuronium, or atracurium to facilitate tracheal intubation and received no more relaxant thereafter. Neuromuscular blockade was not reversed at the end of the procedure. On arrival in the postanesthesia care unit, the TOF ratio was measured at the adductor pollicis, using acceleromyography. Head lift, tongue depressor test, and manual assessment of TOF and DBS fade were also performed. The time delay between the injection of muscle relaxant and quantitative measurement of neuromuscular blockade was calculated from computerized anesthetic records.

Results
The TOF ratios less than 0.7 and 0.9 were observed in 16% and 45% of the patients, respectively. Two hundred thirty-nine patients were tested 2 h or more after the administration of the muscle relaxant. Ten percent of these patients had a TOF ratio less than 0.7, and 37% had a TOF ratio less than 0.9. Clinical tests (head lift and tongue depressor) and manual assessment of fade showed a poor sensitivity (11-14%) to detect residual blockade (TOF < 0.9).

Conclusion
After a single dose of intermediate-duration muscle relaxant and no reversal, residual paralysis is common, even more than 2 h after the administration of muscle relaxant. Quantitative measurement of neuromuscular transmission is the only recommended method to diagnose residual block.
Comparison of Point-of-Care Versus Central Laboratory Measurement of Electrolyte Concentrations on Calculations of the Anion Gap and the Strong Ion Difference
Authors: Morimatsu Hiroshi , Rocktäschel Jens , Bellomo Rinaldo , Uchino Shigehiko , Goldsmith Donna , Gutteridge Geoffrey 
Published: November 2003

Background
Clinicians calculate the anion gap (AG) and the strong ion difference (SID) to make acid-base diagnoses. The technology used is assumed to have limited impact. The authors hypothesized that different measurement technologies markedly affect AG and SID values.

Methods
SID and AG were calculated using values from the point-of-care blood gas and electrolyte analyzer and the central hospital laboratory automated blood biochemistry analyzer. Simultaneously measured plasma sodium, potassium, and chloride concentrations were also compared.

Results
Mean values for central laboratory and point-of-care plasma sodium concentration were significantly different (140.4 +/- 5.6 vs. 138.3 +/- 5.9 mm; P < 0.0001), as were those for plasma chloride concentration (102.4 +/- 6.5 vs. 103.4 +/- 6.0 mm; P < 0.0001) but not potassium. Mean AG values calculated with the two different measurement techniques differed significantly (17.6 +/- 6.2 mEq/l for central laboratory vs. 14.5 +/- 6.0 mEq/l for point-of-care blood gas analyzer; P < 0.0001). Using the Stewart-Figge methodology, SID values also differed significantly (43.7 +/- 4.8 vs. 40.7 +/- 5.6 mEq/l; P < 0.0001), with mean difference of 3.1 mEq/l (95% limits of agreement, -3.4, 9.5 mEq/l). For 83 patients (27.6%), differences in AG values were as high as 5 mEq/l or more, and for 46% of patients whose AG value was outside the reference range with one technology, a value within normal limits was recorded with the other.

Conclusions
Results with two different measurement technologies differed significantly for plasma sodium and chloride concentrations. These differences significantly affected the calculated AG and SID values and might lead clinicians to different assessments of acid-base and electrolyte status.
Accelerometry of Adductor Pollicis Muscle Predicts Recovery of Neuromuscular Blockade in Anesthetized Patients
Authors: Eikermann Matthias , Groeben Harald , Hüsing Johannes , Peters Jürgen 
Published: November 2003

Background
Residual paralysis increases the risk of pulmonary complications but is difficult to detect. To test the hypothesis that accelerometry predicts effects of residual paralysis on pulmonary and upper airway function, the authors related tests of pulmonary and pharyngeal function to accelerometry of adductor pollicis muscle in 12 partially paralyzed volunteers.

Methods
Rocuronium (0.01 mg/kg + 2-10 microg x kg-1 x min-1) was administered to maintain train-of-four (TOF) ratios (assessed every 15 s) of approximately 0.5 and 0.8 over a period of more than 5 min. The authors evaluated pharyngeal and facial muscle functions during steady state relaxation and performed spirometric measurements every 5 min until recovery. Upper airway obstruction was defined as a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of greater than 1. The TOF ratio associated with "acceptable" pulmonary recovery (forced vital capacity and forced inspiratory volume in 1 s of > or =90% of baseline) was calculated using a linear regression model.

Results
At peak blockade (TOF ratio 0.5 +/- 0.16), forced inspiratory flow was impaired (53 +/- 19%) to a greater degree than forced expiratory flow (75 +/- 20%) with a mean ratio of expiratory and inspiratory flow at 50% of vital capacity of 1.18 +/- 0.6. Upper airway obstruction, observed in 8 of 12 volunteers, paralleled an impaired ability to swallow reported by 10 of 12 volunteers. In contrast, all volunteers except one could sustain a head lift for more than 5 s. The authors calculated that a mean TOF ratio of 0.56 (95% confidence interval, 0.22-0.71) predicts "acceptable" recovery of forced vital capacity, whereas forced inspiratory volume in 1 s was impaired until a TOF ratio of 0.95 (0.82-1.18) was reached. A 100% recovery of TOF ratio predicts an acceptable recovery of forced vital capacity, forced inspiratory volume in 1 s, and mean ratio of expiratory and inspiratory flow at 50% of vital capacity in 93%, 73%, and 88% of measurements (calculated negative predictive values), respectively.

Conclusion
Impaired inspiratory flow and upper airway obstruction frequently occur during minimal neuromuscular blockade (TOF ratio 0.8), and extubation may put the patient at risk. Although a TOF ratio of unity predicts a high probability of adequate recovery from neuromuscular blockade, respiratory function can still be impaired.
Effects of Antidepressants on Function and Viability of Human Neutrophils
Authors: Strümper Danja , Durieux Marcel E. , Hollmann Markus W. , Tröster Barbara , den Bakker Christel G. , Marcus Marco A. E. 
Published: November 2003

Background
Antidepressants are frequently used in chronic pain therapy and are under investigation as long-acting local anesthetics. Because of the structural similarities between antidepressants and local anesthetics, the authors hypothesized that these compounds act similarly, and they investigated the effects of nortriptyline, amitriptyline, imipramine, and fluoxetine on priming and activation of human polymorphonuclear neutrophils (hPMNs).

Methods
Effects of 30-, 120-, and 240-min preincubation with nortriptyline (10(-7)-10(-4) M), amitriptyline (10(-6)-10(-3) M), imipramine (10(-6)-10(-3) M), or fluoxetine (10(-7)-10(-4) M) on O(2)- generation of platelet activating factor-primed (10-6 M) and/or formyl-methionyl-leucyl-phenylalanine-activated (10(-6) M) isolated hPMNs were determined. All data are reported as mean +/- SD (statistics: t test, P < 0.05).

Results
Brief incubation in low concentrations of nortriptyline, amitriptyline, or fluoxetine (all at 10(-5) M) did inhibit priming but not activation of hPMNs. Imipramine (10(-5) M) affected neither priming nor activation. Prolonged incubation in lower concentrations of all antidepressants influenced neither priming nor activation. However, at higher concentrations, all four compounds exerted cytotoxic effects: virtually all hPMNs were killed by amitriptyline and imipramine (both at 10(-3) M) or nortriptyline and fluoxetine (both at 10(-4) M).

Conclusion
Antidepressants, in low concentrations, inhibited priming but not activation of hPMNs. However, at concentrations similar to those attained after local injection, and in marked contrast to local anesthetics, antidepressants are profoundly toxic to hPMNs.