ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundFat embolism to the pulmonary circulation is known to occur during total hip arthroplasty, especially during insertion of a cemented femoral component. Fat and air bubbles may enter the systemic circulation via a patent foramen ovale or through pulmonary circulation.MethodsTo determine whether microemboli to the brain were occurring during total hip arthroplasty, 23 patients underwent transcranial Doppler assessment of emboli to the middle cerebral artery during total hip arthroplasty. Surgery was performed with the patient in the lateral decubitus position so that the probe recorded from the nondependent side.ResultsSuccessful recordings were made in 20 patients, in 8 of 20 patients there were embolic signals, which ranging from 1 to 200. In all eight patients, signals were recorded during impaction of a cemented component or after relocation of the hip. Only one patient showed evidence of emboli with impaction of the acetabulum component. In two patients there were 150 and 200 embolic signals: in both mild respiratory symptoms developed. One patient became overtly agitated during a flurry of emboli.ConclusionCerebral microemboli can occur during total hip arthroplasty. Whether this contributes to changes in postoperative cognitive function is unknown.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundExperimental results suggest that the competence of the internal jugular vein (IJV) valve may be damaged when the IJV is cannulated for insertion of a central venous catheter. It has further been hypothesized that the risk of causing incompetence of the proximally located valve might be reduced by using a more distal site for venous cannulation. The present study evaluated these hypotheses in surgical patients.MethodsNinety-one patients without preexisting incompetence of the IJV valve were randomly assigned to undergo distal or proximal IJV cannulation (≥ 1 cm above or below the cricoid level, respectively). Color Doppler ultrasound was used to study whether new valvular incompetence was present during Valsalva maneuvers after insertion of a central venous catheter, immediately after removal of the catheter, and, in a subset of patients, several months after catheter removal, when compared with baseline findings before cannulation of the IJV.ResultsIncompetence of the IJV valve was frequently induced both by proximal and distal cannulation and catheterization of the IJV. Its incidence was higher after proximal than after distal cannulation (76%vs.41%;P< 0.01) and tended to be so after removal of the catheter (47%vs.28%;P= 0.07). Valvular incompetence persisting immediately after removal of the catheter did not recover within 8–27 months in most cases.ConclusionsCannulation and catheterization of the IJV may cause persistent incompetence of the IJV valve. Choosing a more distal site for venous cannulation may slightly lower the risk of causing valvular incompetence but does not reliably avoid it.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundRenal dysfunction after cardiac surgery occurs in up to 8% of patients and is associated with major increases in morbidity, mortality, and cost. Genetic polymorphisms have been implicated as a factor in the progression of chronic renal disease, but a genetic basis for the development of acute renal impairment has not been investigated. The authors therefore tested the hypothesis that apolipoprotein E alleles are associated with different postoperative changes in serum creatinine after cardiac surgery.MethodsThe authors performed a prospective observational study with use of data from 564 coronary bypass surgical patients who were enrolled in an ongoing investigation of apolipoprotein E genotypes and organ dysfunction at a university hospital between 1989–1999. Renal function was assessed among apolipoprotein E genotype groups by comparisons of preoperative (CrPre), peak in-hospital postoperative (CrMax) and perioperative change (DCr) in serum creatinine values.ResultsThe &egr;4 allele grouping (E2 = 2/2,2/3,2/4; E3 = 3/3; E4 = 3/4,4/4) was associated with a smaller increase in postoperative serum creatinine (perioperative change: E4, +0.17; E3, +0.26; E4, +0.27 mg/dl) and a lower peak postoperative creatinine than the &egr;2 and &egr;3 in univariate and multivariate analysis (peak in-hospital postoperative serum creatinine multivariate P = 0.015vs.&egr;3,P= 0.038vs.&egr;2). There was no difference in baseline creatinine among allele groups.ConclusionsInheritance of the apolipoprotein &egr;4 allele is associated with reduced postoperative increase in serum creatinine after cardiac surgery, compared with the &egr;3 or &egr;2 allele. This is the first report of a possible genetic basis for acute renal impairment. These data may contribute to renal risk stratification for cardiac surgery and raise questions regarding apolipoprotein E and the pathophysiology of acute renal injury.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundAlthough nitrous oxide (N2O) is used commonly during anesthesia, clinically relevant advantages–disadvantages of using this agent are not well established in the ambulatory setting. This study in women undergoing ambulatory gynecologic surgery compares outcomes in patients administered total intravenous anesthesia with propofol versus the propofol plus N2O. The primary outcome was the time to home readiness. Secondary outcomes included the incidence of postanesthetic adverse events.MethodsWomen presenting for elective ambulatory termination of pregnancy or gynecologic laparoscopy were induced with an intravenous sleep dose of propofol and fentanyl. After induction, subjects were randomly allocated to maintenance anesthesia with propofol alone or propofol plus 65% N2O. Patients were assessed by a blinded observer in the postanesthetic care unit at 20-min intervals to determine home readiness. Postoperative pain and nausea were measured with visual analog scales. Postoperative analgesics and antiemetics were recorded. The incidence of adverse events occurring after hospital discharge was assessed by a telephone interview 24 h postoperatively.ResultsA total of 740 patients received propofol alone, and 750 patients received propofol plus N2O. Mean home readiness times were not significantly different between treatment groups. There were no significant differences between groups in pain scores, nausea scores, analgesia administration, or antiemetic administration before discharge. There were no significant differences in the frequency of adverse events for 24 h after discharge from hospital.ConclusionsOmission of N2O from a propofol-based anesthetic for ambulatory gynecologic surgery does not affect time to home readiness or the incidence of postoperative adverse events up to 24 h after discharge from hospital.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe intubating laryngeal mask airway (ILMA) is designed to facilitate blind tracheal intubation. The effect of a muscle relaxant on the ability to perform tracheal intubation through the ILMA device has not been previously evaluated. This randomized, double-blind, placebo-controlled study was designed to evaluate rocuronium, 0.2 or 0.4 mg/kg administered intravenously, on the success rate and incidence of complications associated with ILMA-assisted tracheal intubation.MethodsA total of 75 healthy patients were induced with propofol 2 mg/kg and fentanyl 1 &mgr;g/kg intravenously. After insertion of the ILMA device, patients were administered either saline, rocuronium 0.2 mg/kg, or rocuronium 0.4 mg/kg in a total volume of 5 ml. At 90 s after administration of the study drug, tracheal intubation was attempted using a disposable polyvinyl tube. If unsuccessful, a reusable silicone tube was tried. In addition to recording the time and number of attempts required to secure the airway, the incidence of complications during placement of the tracheal tube and removal of the ILMA were noted.ResultsTracheal intubation was successful in 76–96% of the patients. The overall success rates and times required to secure the airway were similar in all three treatment groups. The high-dose rocuronium group experienced less patient movement (8 vs. 28 and 48%) and coughing (12vs.20 and 52%) than the low-dose rocuronium and saline groups, respectively. Use of rocuronium was also associated with a dose-related decrease in the requirement for supplemental bolus doses of propofol during intubation and removal of the ILMA device.ConclusionsUse of rocuronium did not significantly improve the success rate in performing tracheal intubation through the ILMA. However, it produced dose-related decreases in coughing and movement after tracheal intubation and reduced difficulties associated with removal of the ILMA device.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe most sensitive diagnostic criterion of myasthenia gravis is a decrement in the muscular response to repetitive stimulation. The authors hypothesized that myasthenia gravis patients who show a train-of-four ratio (T4/T1) < 0.9 in the preanesthetic period will have increased sensitivity to nondepolarizing neuromuscular blocking agents compared with myasthenia gravis patients with preanesthetic T4/T1 ≥ 0.9.MethodsAfter institutional review board approval was obtained, 20 electrophysiologically documented myasthenia gravis patients were studied. Current pyridostigmine therapy was continued until the morning of surgery. Before induction of anesthesia, neuromuscular transmission was recorded from the hypothenar muscles using electromyography with train-of-four stimulation of the ulnar nerve. According to the T4/T1 ratio, patients were assigned to the “normal” group (T4/T1 ≥ 0.9) or the “decrement” group (T4/T1 < 0.9). After induction of intravenous anesthesia, the effective dose to achieve a 95% neuromuscular blockade (ED95) for atracurium was assessed with a cumulative bolus technique. Postoperatively, pyridostigmine was titrated to obtain a T4/T1 > 0.75 and to treat residual myasthenic symptoms.ResultsIn 14 patients, preanesthetic T4/T1 was ≥ 0.9 (normal), whereas 6 patients presented with T4/T1 < 0.9 (decrement). Decrement patients had a lower ED95of 0.07 ± 0.03 mg/kg atracurium (mean ± SD) compared with normal patients with an ED95of 0.24 ± 0.11 mg/kg atracurium (P= 0.002). All patients were extubated within 30 min after surgery. Postoperative pyridostigmine infusion did not differ significantly between groups.ConclusionsThe requirement for atracurium is significantly reduced in myasthenia gravis patients with a T4/T1 ratio < 0.9 before anesthesia. This study indicates that routine neuromuscular monitoring in myasthenia gravis patients should be extended into the preinduction period to identify patients who require less atracurium.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundBurn patients have impaired myocardial function and decreased &bgr;-adrenergic responsiveness. Further &bgr;-adrenergic dysfunction from systemic absorption of topically administered epinephrine that is given to limit blood loss during burn excision could affect perioperative management. The authors evaluated the effect of topical epinephrine administration to patients during burn excision on the lymphocytic &bgr;-adrenergic response.MethodsFifty-five patients (age, 2–18 yr) with 20–90% body surface area burns received a standardized anesthetic for a burn excision procedure. Lymphocyte samples were taken at baseline and 1 and 3 h after the initial use of epinephrine (n = 43) or thrombin (controls, n = 12). Plasma epinephrine levels were measured by high-performance liquid chromatography. Lymphocyte &bgr;-adrenergic responsiveness was assessed by measuring production of cyclic adenosine monophosphate (cAMP) after stimulation with isoproterenol, prostaglandin E1(PGE1), and forskolin. &bgr;-adrenergic receptor binding assays using iodopindolol and CGP12177 yielded &bgr;-adrenergic receptor density.ResultsEpinephrine levels were elevated at 1 h (P< 0.01) and 3 h (P< 0.01) after epinephrine use but not in control patients. Production of cAMP in lymphocytes 1 h after epinephrine was greater in patients receiving epinephrine than in control patients on stimulation with isoproterenol (P< 0.05) and PGE1(P< 0.05). Three hours after epinephrine administration, production of cAMP decreased when compared with baseline in both control patients and those receiving epinephrine after stimulation with isoproterenol (P< 0.05), PGE1(P< 0.05), and forskolin (P< 0.05). Lymphocytic &bgr;-adrenergic receptor content was not changed.ConclusionsTopical epinephrine to limit blood loss during burn excision resulted in significant systemic absorption and increased plasma epinephrine levels. Acute sensitization of the lymphocytic &bgr;-adrenergic cascade was induced by the administration of epinephrine reflected by increased cAMP production after stimulation with isoproterenol and PGE1. The lymphocytic &bgr;-adrenergic cascade exhibited homologous and heterologous desensitization 3 h after the use of epinephrine or thrombin, indicating that epinephrine administration was not a causative factor.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe ability of leukocytes to release proinflammatory cytokines on lipopolysaccharide stimulation in vitro is impaired after cardiopulmonary bypass (CPB). This study tested contribution and interaction of humoral factors in altered leukocyte responsiveness to lipopolysaccharide.MethodsWhole blood and isolated peripheral-blood mononuclear cells (PBMCs) from 10 patients obtained after induction of anesthesia (T1) and 20 min (T2) and 24 h (T3) after CPB were cultured in the absence or presence of lipopolysaccharide and assessed for release of tumor necrosis factor &agr; (TNF-&agr;) and interleukin (IL)-1&bgr; and their functional antagonists, IL-1 receptor antagonist (IL-1ra) and IL-10. In addition, dose–response characteristics and interaction of IL-10 and norepinephrine as modulators of TNF-&agr; release were studied.ResultsCardiopulmonary bypass induced release of antiinflammatory (T2: IL-10: median 25 pg/ml, 25th–75th percentile 9–42; IL-1ra: median 1,528 pg/ml, 25th–75th percentile 1,075–17,047;P< 0.05 compared with T1) but failed to induce proinflammatory cytokines (T2: TNF-&agr;: median 0 pg/ml, 25th–75th percentile 0–6; IL-1&bgr;: median 1 pg/ml, 25th–75th percentile 0–81; nonsignificant). Removal of plasma at T2increased TNF-&agr; response to lipopolysaccharide (+83.8%;P< 0.05), whereas it suppressed IL-10 (−36.8%;P< 0.05). Similarly, incubation of PBMCs (T1) with plasma obtained after CPB (T2) as well as addition of IL-10 or norepinephrine in concentrations present in plasma after CPB led to a reduced lipopolysaccharide-stimulated TNF-&agr; and an increased IL-10 response. Coadministration of norepinephrine and IL-10 had synergistic effects. Although pretreatment with an anti–IL-10 antibody and labetalol before addition of plasma obtained at T2largely restored the TNF-&agr; responsein vitro, their addition post-treatment failed to restore the monocytic TNF-&agr; response.ConclusionsPlasma contains interacting factors that inhibit the release of TNF-&agr; and increase the release of IL-10, presumably attenuating the inflammatory response to CPB. Although norepinephrine fails to induce a cytokine response in the absence of other stimuli, its administration seems to augment the antiinflammatory IL-10 response while attenuating the TNF-&agr; response.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID