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

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundDuring experimental cardiac arrest, continuous insufflation of air or oxygen (CIO) through microcannulas inserted into the inner wall of a modified intubation tube and generating a permanent positive intrathoracic pressure, combined with external cardiac massage, has previously been shown to be as effective as intermittent positive pressure ventilation (IPPV).MethodsAfter basic cardiorespiratory resuscitation, the adult patients who experienced nontraumatic, out-of-hospital cardiac arrest with asystole, were randomized to two groups: an IPPV group tracheally intubated with a standard tube and ventilated with standard IPPV and a CIO group for whom a modified tube was inserted, and in which CIO at a flow rate of 15 l/min replaced IPPV (the tube was left open to atmosphere). Both groups underwent active cardiac compression–decompression with a device. Resuscitation was continued for a maximum of 30 min. Blood gas analysis was performed as soon as stable spontaneous cardiac activity was restored, and a second blood gas analysis was performed at admission to the hospital.ResultsThe two groups of patients (47 in the IPPV and 48 in the CIO group) were comparable. The percentages of patients who underwent successful resuscitation (stable cardiac activity; 21.3 in the IPPV group and 27.1% in the CIO group) and the time necessary for successful resuscitation (11.8 ± 1.8 and 12.8 ± 1.9 min) were also comparable. The blood gas analysis performed after resuscitation (8 patients in the IPPV and 10 in the CIO group) did not show significant differences. The arterial blood gases performed after admission to the hospital and ventilation using a transport ventilator (seven patients in the IPPV group and six in the CIO group) showed that the partial pressure of arterial carbon dioxide (PaCO2) was significantly lower in the CIO group (35.7 ± 2.1 compared with 72.7 ± 7.4 mmHg), whereas thepH and the partial pressure of arterial oxygen (PaO2) were significantly higher (allP< 0.05).ConclusionsContinuous insufflation of air or oxygen alone through a multichannel open tube was as effective as IPPV during out-of-hospital cardiac arrest. A significantly greater elimination of carbon dioxide and a better level of oxygenation in the group previously treated with CIO probably reflected better lung mechanics.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundCell salvage has been used in obstetrics to a limited degree because of a fear of amniotic fluid embolism. In this study, cell salvage was combined with blood filtration using a leukocyte depletion filter. A comparison of this washed, filtered product was then made with maternal central venous blood.MethodsThe squamous cell concentration, lamellar body count, quantitative bacterial colonization, potassium level, and fetal hemoglobin concentration were measured in four sequential blood samples collected from 15 women undergoing elective cesarean section. The blood samples collected included (1) unwashed blood from the surgical field (prewash), (2) washed blood (postwash), (3) washed and filtered blood (postfiltration), and (4) maternal central venous blood drawn from a femoral catheter at the time of placental separation.ResultsSignificant reductions in the following parameters were seen when the postfiltration samples were compared to the prewash samples (median [25th–75th percentile]): squamous cell concentration (0.0 [0.0–0.1 counts/high-powered field (HPF)] vs. 8.3 counts/HPF [4.0–10.5 counts/HPF], ,P< 0.05); bacterial contamination (0.1 [0.0–0.2]vs.3.0 [0.6–7.7] colony-forming units (CFU)/ml,P< 0.01); and lamellar body concentration (0.0 [0.0–1.0]vs.22.0 [18.5–29.5] thousands/&mgr;l,P< 0.01). No significant differences existed between the postfiltration and maternal samples for each of these parameters. Fetal hemoglobin was in higher concentrations in the postfiltration sample when compared with maternal blood (1.9 [1.1–2.5]vs.0.5% [0.3–0.7] ). Potassium levels were significantly less in the postfiltration sample when compared with maternal (1.4 [1.0–1.5]vs.3.8 mEq/l [3.7–4.0]).ConclusionsLeukocyte depletion filtering of cell-salvaged blood obtained from cesarean section significantly reduces particulate contaminants to a concentration equivalent to maternal venous blood.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundDuring childbirth, the maternal need for intensive care unit (ICU) services is not well-defined. This information could influence the decision whether to incorporate ICU services into the labor and delivery suite.MethodsThis study reports (1) ICU use and mortality rates in a statewide population of obstetric patients during their hospital admission for childbirth, and (2) the risk factors associated with ICU admission and mortality. A case–control design using patient records from a state-maintained anonymous database for the years 1984–1997 was used. Outcome variables included ICU use and mortality rates.ResultsOf the 822,591 hospital admissions for delivery of neonates during the study period, there were 1,023 ICU admissions (0.12%) and 34 ICU deaths (3.3%). Age, race, hospital type, volume of deliveries, and source of admission independently and in combination were associated with ICU admission (P < 0.05). The most common risk factors associated with ICU admission included cesarean section, preeclampsia or eclampsia, and postpartum hemorrhage (P< 0.001). Black race, high hospital volume of deliveries, and longer duration of ICU stay were associated with ICU mortality (P< 0.05). The most common risk factors associated with ICU mortality included pulmonary complications, shock, cerebrovascular event, and drug dependence (P< 0.05).ConclusionsThis study shows that ICU use and mortality rate during hospital admission for delivery of a neonate is low. These results may influence the location of perinatal ICU services in the hospital setting.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundRegional analgesia for labor often is initiated with an intrathecal injection of a local anesthetic and opioid. The purpose of this prospective, randomized, blinded study was to determine the optimal dose of intrathecal sufentanil when combined with 2.5 mg bupivacaine for labor analgesia.MethodsOne hundred seventy parous parturients with cervical dilation between 3–5 cm were randomized to receive intrathecal 0 (control), 2.5, 5.0, 7.5, or 10.0 &mgr;g sufentanil combined with 2.5 mg bupivacaine, followed by a lidocaine epidural test dose, for initiation of analgesia (34 patients in each group). Visual analog scores and the presence of nausea, vomiting, and pruritus were determined every 15 min until the patient requested additional analgesia. Fetal heart rate tracings were compared between groups.ResultsGroups were similar for age, height, weight, oxytocin dose, duration of labor, and baseline visual analog scores. Duration of action was significantly shorter for control patients (39 ± 25 min [mean ± SD]) compared with those administered sufentanil, all doses (93 ± 32, 93 ± 47, 94 ± 33, 97 ± 39 min), but was not different among groups administered 2.5, 5.0, 7.5, or 10.0 &mgr;g sufentanil. More patients who received 10 &mgr;g sufentanil reported nausea and vomiting than did control patients. The severity of pruritus increased with administration of 7.5 and 10.0 &mgr;g sufentanil. There was no difference in fetal heart rate changes among groups.ConclusionsIntrathecal bupivacaine (2.5 mg) without sufentanil did not provide satisfactory analgesia for parous patients. However, bupivacaine combined with 2.5 &mgr;g sufentanil provided analgesia comparable to higher doses, with a lower incidence of nausea and vomiting and less severe pruritus.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe pharmacodynamic differences in time to onset and dissipation of effect of sufentanil, fentanyl, and alfentanil probably result from different rates of blood–brain equilibration. The authors investigated this hypothesis in humans.MethodsAfter simultaneous central venous bolus application of sufentanil (10 &mgr;g), fentanyl (100 &mgr;g), and alfentanil (1,000 &mgr;g), arterial and jugular bulb blood samples were drawn simultaneously at 20, 30, 45, 60, 75, 90, 105, 120, 140, 160, 180, 210, 240, 300, 360, and 420 s from 19 patients during the postacute stage of head injury with normal intracranial pressure, cerebral perfusion pressure, and cerebral oxygen metabolism during normocapnia.ResultsPeak brain concentration, indicated by equilibrium between arterial and jugular bulb opioid concentrations, was achieved for alfentanil at 45 s, for sufentanil at 5 min, and for fentanyl at 6 min. The corresponding median time intervals (fifth and ninety-fifth percentiles) to reach 50% of peak brain concentration were 15 (14–18), 25 (18–38) and 35 (25–45) s, respectively. Uptake was highest 20 s after bolus and decreased continuously for fentanyl and sufentanil, whereas alfentanil uptake was biphasic. The ratio of the relative amounts of sufentanil, fentanyl, and alfentanil retained in the brain at peak brain concentration was 1×:×6×:×90.ConclusionsThe differences in the time lag between changes in serum concentrations and drug effect after bolus application of nearly equipotent doses of sufentanil, fentanyl, and alfentanil originate from the different times required to reach blood–brain equilibration, mainly depending on different levels and different time profiles of arterial blood concentrations caused by the different tissue distribution volumes.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe authors hypothesized that intraperitoneal and retroperitoneal carbon dioxide insufflation during surgical procedures evoke markedly different effects on the venous low-pressure system, induce different inferior caval vein pressure gradients at similar insufflation pressures, and may provide evidence for the Starling resistor concept of abdominal venous return.MethodsIntra- and extrathoracic caval vein pressures were measured using micromanometers during carbon dioxide insufflation at six cavity pressures (baseline and 10, 15, 20, and 24 mmHg and desufflation) in 20 anesthetized patients undergoing laparoscopic (supine, n = 8) or left (n = 6) or right (n = 6) retroperitoneoscopic (prone position) surgery. Intracavital, esophageal, and gastric pressures also were assessed. Data were analyzed for insufflation pressure–dependent and group effects by one-way and two-way analysis of variance for repeated measurements, respectively, followed by the Newman–Keuls post hoc test (P< 0.05).ResultsIntraperitoneal, unlike retroperitoneal, insufflation markedly increased, in an insufflation pressure–dependent fashion, the inferior-to-superior caval vein pressure gradient (P< 0.00001) at the level of the diaphragm. In contrast to what was observed with retroperitoneal insufflation, transmural intrathoracic caval vein pressure increased at 10 mmHg insufflation pressure, but the increase flattened with an insufflation pressure of more than 10 mmHg, and pressure decreased with an inflation pressure of 20 mmHg (P= 0.0397). These data are consistent with a zone 2 or 3 abdominal vascular condition during intraperitoneal and a zone 3 abdominal vascular condition during retroperitoneal insufflation.ConclusionsIntraperitoneal but not retroperitoneal carbon dioxide insufflation evokes a transition of the abdominal venous compartment from a zone 3 to a zone 2 condition, presumably impairing venous return, supporting the Starling resistor concept of abdominal venous return in humans.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID

摘要:

BackgroundThe short duration of action of mivacurium results from its rapid hydrolysis by plasma cholinesterase. Bambuterol, an oral bronchodilator, has an inhibiting effect on plasma cholinesterase. The purpose of this study was to evaluate the effect of bambuterol-induced low plasma cholinesterase activity on the pharmacokinetics and pharmacodynamics of mivacurium.MethodsFourteen patients received 20 mg bambuterol and 14 patients received placebo orally 2 h before induction of anesthesia. During anesthesia the neuromuscular block was monitored at the thumb using train-of-four nerve stimulation every 12 s and mechanomyography. The times to different levels of neuromuscular recovery after 0.2 mg/kg mivacurium were measured. The concentrations in venous blood of the three isomers and the metabolites of mivacurium were measured using high-performance liquid chromatography.ResultsPlasma cholinesterase activity was inhibited a median of 90% (range, 67–97%) after bambuterol. The time to first response to train-of-four nerve stimulation was 15 min (range, 9–21 min) and 59 min (range, 32–179 min) in patients receiving placebo and bambuterol, respectively. The estimated clearances of the isomers were significantly lower and the elimination half-lives of all three isomers significantly prolonged in patients receiving bambuterol. No difference was seen in elimination half-lives of the metabolites. The elimination rate constant from the effect compartment and the potency of mivacurium was not affected by bambuterol.ConclusionA 90% inhibition of plasma cholinesterase activity significantly reduced clearance of the isomers of mivacurium. Correspondingly, the duration of action of 0.2 mg/kg mivacurium was prolonged three- to fourfold, compared with patients not administered bambuterol.

ISSN:0003-3022    

出版商:OVID    

年代:2000

数据来源: OVID