ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundWhether the fetus can experience pain remains controversial. During the last half of pregnancy, the neuroanatomic connections for nociception are in place, and the human fetus mounts sizable stress responses to physical insults. Analgesia has been recommended for intrauterine procedures or late termination, but without evidence that it works. The authors investigated whether fentanyl ablates the fetal stress response to needling using the model of delayed interval sampling during intrahepatic vein blood sampling and transfusion in alloimmunized fetuses undergoing intravascular transfusion between 20 and 35 weeks.MethodsIntravenous fentanyl (10 &mgr;g/kg estimated fetal weight × 1.25 placental correction) was given once at intrahepatic vein transfusion in 16 fetuses, and changes (posttransfusion − pretransfusion) in &bgr; endorphin, cortisol, and middle cerebral artery pulsatility index were compared with intrahepatic vein transfusions without fentanyl and with control transfusions at the placental cord insertion.ResultsFentanyl reduced the &bgr; endorphin (mean difference in changes, −70.3 pg/ml; 95% confidence interval, −121 to −19.2;P= 0.02) and middle cerebral artery pulsatility index response (mean difference, 0.65; 95% confidence interval, 0.26–1.04;P= 0.03), but not the cortisol response (mean difference, −10.9 ng/ml, 95% confidence interval, −24.7 to 2.9;P= 0.11) in fetuses who had paired intrahepatic vein transfusions with and without fentanyl. Comparison with control fetuses transfused without fentanyl indicated that the &bgr; endorphin and cerebral Doppler response to intrahepatic vein transfusion with fentanyl approached that of nonstressful placental cord transfusions.ConclusionsThe authors conclude that intravenous fentanyl attenuates the fetal stress response to intrahepatic vein needling.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThe “sniffing position” is recommended for optimization of glottic visualization under direct laryngoscopy. However, no study to date has confirmed its superiority over simple head extension. In a prospective, randomized study, the authors compared the sniffing position with simple head extension in orotracheal intubation.MethodsThe study included 456 consecutive patients. The sniffing position was obtained by placement of a 7-cm cushion under the head of the patient. The extension position was obtained by simple head extension. The anesthetic procedure included two laryngoscopies without paralysis: the first was used for topical glottic anesthesia. During the second direct laryngoscopy, intubation of the trachea was performed. The head position was randomized as follows: group A was in the sniffing position during the first laryngoscopy and the extension position during the second; group B was in the extension position during the first laryngoscopy and the sniffing position during the second. Glottic exposure was assessed by the Cormack scale.ResultsThe sniffing position improved glottic exposure (decreased the Cormack grade) in 18% of patients and worsened it (increased the Cormack grade) in 11% of patients, in comparison with simple extension. The Cormack grade distribution was not significantly modified between the two groups. Multivariate analysis showed that reduced neck mobility and obesity were independently related to improvement in laryngoscopic view with application of the sniffing position.ConclusionsRoutine use of the sniffing position appears to provide no significant advantage over simple head extension for tracheal intubation in this setting. The sniffing position appears to be advantageous in obese and head extension–limited patients.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundRenal impairment often follows cardiac surgery. The authors investigated whether sevoflurane produces greater increases in plasma creatinine concentration than isoflurane or propofol after elective coronary artery surgery.MethodsAs part of maintenance anesthesia, including during cardiopulmonary bypass, patients were randomly allocated to receive one of three agents: isoflurane (n = 118), sevoflurane (n = 118), or propofol (n = 118). Fresh gas flows were 3 l/min. The preoperative plasma creatinine concentration was subtracted from the highest creatinine concentration in the first 3 postoperative days. A median maximum increase greater than 44 &mgr;m (0.5 mg/dl) was regarded as clinically important. Data were analyzed on an intention-to-treat basis. Subgroup analyses were performed on per-protocol patients and those with preoperative renal impairment (creatinine concentration > 130 &mgr;m [1.47 mg/dl] or urea > 7.7 mm [blood urea nitrogen, 21.6 mg/dl]).ResultsThe differences between the groups were small, clinically unimportant, and not statistically significant for the primary analysis and subgroups. The proportions of patients with creatinine increases greater than 44 &mgr;m were 15% in the isoflurane group, 17% in the sevoflurane group, and 11% in the propofol group (P= 0.45). The median increases were 8 &mgr;m in the isoflurane group, 4 &mgr;m in the sevoflurane group, and 6 &mgr;m in the propofol group. The differences between the three median maximum increases were 1–4 &mgr;m (P> 0.45). In the subgroup with preoperative renal impairment, the median increases were 10 &mgr;m in the isoflurane group, 15 &mgr;m in the sevoflurane group, and 5 &mgr;m in the propofol group (P= 0.72).ConclusionsSevoflurane did not produce greater increases in creatinine than isoflurane or propofol after elective coronary artery surgery.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundThe impact of acute preoperative volume loading with colloids on blood volume has not been investigated sufficiently.MethodsBefore surgery, in 20 patients undergoing major gynecologic procedures, volume loading was performed during anesthesia by infusing approximately 20 ml/kg of colloid at a rate of 90 ml/min (group I: 5% albumin solution; group II: 6% hetastarch solution; n = 10 each). Plasma volume (indocyanine green dilution technique), erythrocyte volume (labeling erythrocytes with fluorescein), hematocrit, total protein, and hetastarch plasma concentrations (group II) were measured before and 30 min after the end of infusion.ResultsMore than 1,350 ml of colloid (approximately 50% of the baseline plasma volume) were infused within 15 min. Thirty minutes after the infusion had been completed, blood volume was only 524 ± 328 ml (group I) and 603 ± 314 ml (group II) higher than before volume loading. The large vessel hematocrit (measured by centrifugation) dropped more than the whole body hematocrit, which was derived from double-label measurements of blood volume.ConclusionsThe double-label measurements of blood volume performed showed that 30 min after the infusion of approximately 20 ml/kg of 5% albumin or 6% hetastarch solution (within 15 min), only mean 38 ± 21% and 43 ± 26%, respectively, of the volume applied remained in the intravascular space. Different,i.e., earlier or later, measuring points, different infusion volumes, infusion rates, plasma substitutes, or possibly different tracers for plasma volume measurement might lead to different results concerning the kinetics of fluid or colloid extravasation.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID

摘要:

BackgroundAmbulatory epidural analgesia (AEA) is a popular choice for labor analgesia because ambulation reportedly increases maternal comfort, increases the intensity of uterine contractions, avoids inferior vena cava compression, facilitates fetal head descent, and relaxes the pelvic musculature, all of which can shorten labor. However, the preponderance of evidence suggests that ambulation during labor is not associated with these benefits. The purpose of this study is to determine whether ambulation with AEA decreases labor duration from the time of epidural insertion to complete cervical dilatation.MethodsIn this prospective, randomized study, 160 nulliparous women with AEA were randomly assigned to one of two groups: AEA with ambulation and AEA without ambulation. AEA blocks were initiated with 15–20 ml ropivacaine (0.07%) plus 100 &mgr;g fentanyl, followed by a continuous infusion of 0.07% ropivacaine plus 2 &mgr;g/ml fentanyl at 15–20 ml/h. Maternal measured variables included ambulation time, time from epidural insertion to complete dilatation, stage II duration, pain Visual Analogue Scale scores, and mode of delivery. APGAR scores were recorded at 1 and 5 min. Results are expressed as mean ± SD or median and analyzed using thettest, chi-square, or the Mann–Whitney test atP≤ 0.05.ResultsThe ambulatory group walked 25.0 ± 23.3 min, sat upright 40.3 ± 29.7 min, or both. Time from epidural insertion to complete dilatation was 240.9 ± 146.1 min in the ambulatory group and 211.9 ± 133.9 min in the nonambulatory group (P= 0.206).ConclusionAmbulatory epidural analgesia with walking or sitting does not shorten labor duration from the time of epidural insertion to complete cervical dilatation.

ISSN:0003-3022    

出版商:OVID    

年代:2001

数据来源: OVID