ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundElectromyographic activity has previously been reported to elevate the Bispectral Index (BIS) in patients not receiving neuromuscular blockade while under sedation in the intensive care unit. This study aimed to investigate the magnitude of the decrease of BIS following administration of muscle relaxant in sedated intensive care unit patients.MethodsThe authors prospectively investigated 45 patients who were continuously sedated with midazolam and sufentanil to achieve a Sedation-Agitation Scale value equal to 1 and who required administration of muscle relaxant. BIS (BIS® version 2.10), electromyography, and acceleromyography at the adductor pollicis muscle were recorded simultaneously before and after neuromuscular blockade. Sixteen of these 45 patients were also studied simultaneously with the new BIS® XP.ResultsAfter administration of a muscle relaxant, BIS (67 ± 19vs.43 ± 10,P< 0.001) and electromyographic activity (37 ± 9vs.27 ± 3 dB,P< 0.001) significantly decreased. Multiple regression analysis showed that the decrease of BIS following administration of myorelaxant was significantly correlated to BIS and electromyographic baseline values. Using standard BIS range guidelines, the number of patients under light or deep sedationversusgeneral anesthesia or deep hypnotic state was markedly overestimated before administration of myorelaxant (53vs.2%,P< 0.001).ConclusionsThe BIS in sedated intensive care unit patients may be lower with paralysis for an equivalent degree of sedation because of high muscular activity. The magnitude of BIS overestimation is significantly correlated to both BIS and electromyographic activity before neuromuscular blockade. The authors conclude that clinicians who determine the amount of sedation in intensive care unit patients only from BIS monitoring may expose them to unnecessary oversedation.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundAfter induction of anesthesia, lung resistance increases. The authors hypothesized that prophylactic bronchodilator treatment with intravenous colforsin daropate, a water-soluble forskolin derivative, before tracheal intubation would result in decreased lung resistance and increased lung compliance after tracheal intubation when compared with placebo medication.MethodsForty-six adult patients were randomized to placebo or colforsin daropate treatment. Patients in the control group received normal saline; patients in the colforsin group received 0.75 &mgr;g · kg−1· min−1colforsin daropate intravenously until the study ended. Thirty minutes after the study began, the authors administered 5 mg/kg thiamylal and 5 &mgr;g/kg fentanyl for induction of general anesthesia and 0.3 mg/kg vecuronium for muscle relaxation. A 15-mg · kg−1· h−1continuous infusion of thiamylal followed anesthetic induction. Four, 8, 12, and 16 min after tracheal intubation, mean airway resistance (Rawm), expiratory airway resistance (Rawe), and dynamic lung compliance (Cdyn) were measured.ResultsPatients in the colforsin group had significantly lower Rawmand Raweand higher Cdynafter intubation than those in the control group. Differences in Rawm, Rawe, and Cdynbetween the two groups persisted through the final measurement at 16 min. At 4 min after intubation, smokers had a higher Rawmand a lower Cdynthan nonsmokers in the control group. After treatment by intravenous colforsin daropate, Rawm, Rawe, and Cdynvalues were similar for smokers and nonsmokers after tracheal intubation.ConclusionsProphylactic treatment with colforsin daropate produced lower Rawmand Raweand higher Cdynafter tracheal intubation when compared with placebo medication. Pretreatment before intubation may be beneficial and advantageous for middle-aged smokers.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe authors examined the role of adenosine triphosphate–sensitive potassium channels and adenosine A1receptors in sevoflurane-induced preconditioning on isolated human myocardium.MethodsThe authors recorded isometric contraction of human right atrial trabeculae suspended in oxygenated Tyrode's solution (34°C; stimulation frequency, 1 Hz). In all groups, a 30-min hypoxic period was followed by 60 min of reoxygenation. Seven minutes before hypoxia reoxygenation, muscles were exposed to 4 min of hypoxia and 7 min of reoxygenation or 15 min of sevoflurane at concentrations of 1, 2, and 3%. In separate groups, sevoflurane 2% was administered in the presence of 10 &mgr;m HMR 1098, a sarcolemmal adenosine triphosphate–sensitive potassium channel antagonist; 800 &mgr;m 5-hydroxy-decanoate, a mitochondrial adenosine triphosphate–sensitive potassium channel antagonist; and 100 nm 8-cyclopentyl-1,3-dipropylxanthine, an adenosine A1receptor antagonist. Recovery of force at the end of the 60-min reoxygenation period was compared between groups (mean ± SD).ResultsHypoxic preconditioning (90 ± 4% of baseline) and sevoflurane 1% (82 ± 3% of baseline), 2% (92 ± 5% of baseline), and 3% (85 ± 7% of baseline) enhanced the recovery of force after 60 min of reoxygenation compared with the control groups (52 ± 9% of baseline). This effect was abolished in the presence of 5-hydroxy-decanoate (55 ± 14% of baseline) and 8-cyclopentyl-1,3-dipropylxanthine (58 ± 16% of baseline) but was attenuated in the presence of HMR 1098 (73 ± 10% of baseline).ConclusionsIn vitro, sevoflurane preconditions human myocardium against hypoxia through activation of adenosine triphosphate–sensitive potassium channels and stimulation of adenosine A1receptors.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundThe Narcotrend is a new electroencephalographic monitor designed to measure depth of anesthesia, based on a six-letter classification from A (awake) to F (increasing burst suppression) including 14 substages. This study was designed to investigate the impact of Narcotrend monitoring on recovery times and propofol consumption in comparison to Bispectral Index® (BIS®) monitoring or standard anesthetic practice.MethodsWith institutional review board approval and written informed consent, 120 adult patients scheduled to undergo minor orthopedic surgery were randomized to receive a propofol–remifentanil anesthetic controlled by Narcotrend, by BIS®, or solely by clinical parameters. Anesthesia was induced with 0.4 &mgr;g · kg−1· min−1remifentanil and a propofol target-controlled infusion at 3.5 &mgr;g/ml. After intubation, remifentanil was reduced to 0.2 &mgr;g · kg−1· min−1, whereas the propofol infusion was adjusted according to clinical parameters or to the following target values: during maintenance to D0(Narcotrend) or 50 (BIS®); 15 min before the end of surgery to C1(Narcotrend) or 60 (BIS®). Recovery times were recorded by a blinded investigator, and average normalized propofol consumption was calculated from induction and maintenance doses.ResultsThe groups were comparable for demographic data, duration of anesthesia, and mean remifentanil dosages. Compared with standard practice, patients with Narcotrend or BIS® monitoring needed significantly less propofol (standard practice, 6.8 ± 1.2 mg · kg−1· h−1vs.Narcotrend, 4.5 ± 1.1 mg · kg−1· h−1or BIS®, 4.8 ± 1.0 mg · kg−1· h−1;P< 0.001), opened their eyes earlier (9.3 ± 5.2vs.3.4 ± 2.2 or 3.5 ± 2.9 min), and were extubated sooner (9.7 ± 5.3vs.3.7 ± 2.2 or 4.1 ± 2.9 min).ConclusionsThe results indicate that Narcotrend and BIS® monitoring are equally effective to facilitate a significant reduction of recovery times and propofol consumption when used for guidance of propofol titration during a propofol–remifentanil anesthetic.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundHydroxyethyl starch (HES) 130/0.4 may impair blood coagulation less than other HES solutions and, thus, may be used at larger doses without increasing the risk of postoperative bleeding. This study tested the hypothesis that volume replacement with 6% HES 130/0.4 at a dose of up to 50 ml/kg does not increase blood loss and transfusion requirements in elective coronary artery bypass surgery compared with 6% HES 200/0.5 at a dose of up to 33 ml/kg.MethodsOne hundred twenty adult patients scheduled for elective coronary artery bypass surgery were randomized to receive up to 50 ml/kg of 6% HES 130/0.4 or up to 33 ml/kg of 6% HES 200/0.5 for volume replacement during surgery and until 24 h thereafter. Volume requirements in excess of the respective maximum dose of HES were treated with gelatin. Colloid use was at the discretion of the attending physicians and not dictated by protocol. The primary outcome variable was chest tube drainage volume during the first 24 h after surgery.ResultsThe data from 117 patients (HES 130/0.4, 59 patients; HES 200/0.5, 58 patients) who completed the study according to protocol were analyzed. The median volumes of HES administered were 49 and 33 ml/kg in the HES 130/0.4 and HES 200/0.5 groups, respectively (P< 0.001). Consequently, patients in the HES 130/0.4 group required less gelatin in addition to HES than those in the HES 200/0.5 group (medians: 7 ml/kgvs.20 ml/kg,P< 0.001). The combined volumes of HES and gelatin were similar for both groups (P= 0.21). The 24-h chest tube drainage (medians: 660 mlvs.705 ml,P= 0.60) did not differ significantly between the groups, nor did transfusion outcome.ConclusionSix percent HES 130/0.4 at a median dose of 49 ml/kg did not increase blood loss and transfusion requirements in coronary artery bypass surgery compared with 6% HES 200/0.5 at a median dose of 33 ml/kg.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID

摘要:

BackgroundAn aortic-to-radial arterial pressure gradient may develop during and after cardiopulmonary bypass (CPB). The mechanisms of this pressure gradient remain controversial. To clarify the cause of the pressure gradient after CPB, the authors investigated the relationship between the pressure gradient and changes in the pulse wave velocity (PWV) before and after CPB.MethodsThe pressure gradient from the aorta to the radial artery and a change in PWV were measured with a wire (0.37 mm in diameter) tipped with a miniature pressure transducer in 12 patients undergoing cardiac surgery. The pressure distributions and waveforms were measured and recorded with electrocardiograph. The PWV was calculated by measuring the propagation time between the R wave of the electrocardiograph and the rising point of the arterial pressure waveform at 10-cm intervals.ResultsAfter CPB, 7 of 12 patients demonstrated a marked pressure gradient. In these patients, the pressure distribution showed a gradual decrease toward the periphery without a precipitous step-down in pressure at any one specific anatomic location. The PWV decreased as the intraarterial pressure decreased from the aorta to the radial artery, and the relative arterial elasticity decreased linearly toward the periphery.ConclusionsThe results showed that the decrease in PWV implies a decrease in arterial elasticity, and the decrease in the arterial elasticity correlated with the decrease in intraarterial pressure. These findings demonstrated that a radial artery pressure lower than the aortic pressure after CPB may be due to the decrease in arterial elasticity.

ISSN:0003-3022    

出版商:OVID    

年代:2003

数据来源: OVID