ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundIn dogs, sheep, and rats, spinal neostigmine produces analgesia alone and enhances analgesia from alpha2‐adrenergic agonists. This study assesses side effects and analgesia from intrathecal neostigmine in healthy volunteers.MethodsAfter institutional review board approval and informed consent, 28 healthy volunteers were studied. The first 14 volunteers received neostigmine (50–750 micro gram) through a #19.5 spinal needle followed by insertion of a spinal catheter. The remaining 14 volunteers received neostigmine through a #25 or #27 spinal needle without a catheter. Safety measurements included blood pressure, heart rate, oxyhemoglobin saturation, end‐tidal carbon dioxide, neurologic evaluation, and computer tests of vigilance and memory. Analgesia in response to ice water immersion was measured.ResultsNeostigmine (50 micro gram) through the #19.5 needle did not affect any measured variable. Neostigmine (150 micro gram) caused mild nausea, and 500–750 micro gram caused severe nausea and vomiting. Neostigmine (150–750 micro gram) produced subjective leg weakness, decreased deep tendon reflexes, and sedation. The 750‐micro gram dose was associated with anxiety, increased blood pressure and heart rate, and decreased end‐tidal carbon dioxide. Neostigmine (100–200 micro gram) in saline, injected through a #25 or #27 needle, caused protracted, severe nausea, and vomiting. This did not occur when dextrose was added to neostigmine. Neostigmine by either method of administration reduced visual analog pain scores to immersion of the foot in ice water.ConclusionsThe incidence and severity of these adverse events from intrathecal neostigmine appears to be affected by dose, method of administration, and baricity of solution. These effects in humans are consistent with studies in animals. Because no unexpected or dangerous side effects occurred, cautious examination of intrathecal neostigmine alone and in combination with other agents for analgesia is warranted.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundBrain temperature is closely approximated by most body temperature measurements under normal anesthetic conditions. However, when thermal autoregulation is overridden, large temperature gradients may prevail. This study sought to determine which of the standard temperature monitoring sites best approximates brain temperature when deep hypothermia is rapidly induced and reversed during cardiopulmonary bypass.MethodsTwenty‐seven patients underwent cardiopulmonary bypass and deep hypothermic circulatory arrest in order for each to have a giant cerebral aneurysm surgically clipped. Brain temperatures were measured directly with a thermocouple embedded in the cerebral cortex. Eight other body temperatures were monitored simultaneously with less invasive sensors at standard sites.ResultsBrain temperature decreased from 32.6 + 1.4 degrees Celsius (mean plus/minus SD) to 16.7 plus/minus 1.7 degrees Celsius in 28 plus/minus 7 min, for an average cerebral cooling rate of 0.59 + 0.15 degree Celsius/min. Circulatory arrest lasted 24 plus/minus 15 min and was followed by 63 + 17 min of rewarming at 0.31 plus/minus 0.09 degree Celsius/min. None of the monitored sites tracked cerebral temperature well throughout the entire hypothermic period. During rapid temperature change, nasopharyngeal, esophageal, and pulmonary artery temperatures corresponded to brain temperature with smaller mean differences than did those of the tympanic membrane, bladder, rectum, axilla, and sole of the foot. At circulatory arrest, nasopharyngeal, esophageal, and pulmonary artery mean temperatures were within 1 degree Celsius of brain temperature, even though individual patients frequently exhibited disparate values at those sites.ConclusionsWhen profound hypothermia is rapidly induced and reversed, temperature measurements made at standard monitoring sites may not reflect cerebral temperature. Measurements from the nasopharynx, esophagus, and pulmonary artery tend to match brain temperature best but only with an array of data can one feel comfortable disregarding discordant readings.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundLaparoscopic pronuclear stage transfer (PROST) is the preferred method of embryo transfer after in vitro fertilization in many infertility programs. There are scant data to recommend the use or avoidance of any particular anesthetic agent for use in women undergoing this procedure. The authors hypothesized that propofol would be an ideal anesthetic for laparoscopic PROST because of its characteristic favorable recovery profile that includes minimal sedation and a low incidence of postoperative nausea and vomiting. The purpose of the study was to compare propofol and isoflurane with respect to postanesthetic recovery and pregnancy outcomes after laparoscopic PROST.MethodsOne hundred twelve women scheduled for laparoscopic PROST were randomized to receive either propofol/nitrous oxide or isoflurane/nitrous oxide for maintenance of anesthesia.ResultsVisual analog scale scores for sedation were lower in the propofol group than in the isoflurane group at all measurements between 30 min and 3 h after surgery. More women experienced emesis and were given an antiemetic during recovery in the isoflurane group than in the propofol group. However, the percentage of pregnancies with evidence of fetal cardiac activity was 54% in the isoflurane group compared with only 30% in the propofol group (P = 0.023). Also, the ongoing pregnancy rate was greater in the isoflurane group than in the propofol group (54% vs. 29%, P = 0.014).ConclusionsPropofol/nitrous oxide anesthesia was associated with lower clinical and ongoing pregnancy rates compared with isoflurane/nitrous oxide anesthesia.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundHalothane and isoflurane have been shown to induce disparate effects on different brain structures in animals. In humans, various methods for measuring cerebral blood flow (CBF) have produced results compatible with a redistribution of CBF toward deep brain structures during isoflurane anesthesia in humans. This study was undertaken to examine the effects of halothane and isoflurane on the distribution of CBF.MethodsTwenty ASA physical status patients (four groups, five in each) anesthetized with either isoflurane or halothane (1 MAC) during normo‐ or hypocapnia (PaCO25.6 or 4.2 kPa (42 or 32 mmHg)) were investigated with a two‐dimensional CBF measurement (CBFxenon, intravenous133xenon washout technique) and a three‐dimensional method for measurement of the regional CBF (rCBF) distribution with single photon emission computer‐aided tomography (SPECT;99mTc‐HMPAO). In the presentation of SPECT data, the mean CBF of the brain was defined as 100%, and all relative flow values are related to this value.ResultsThe mean CBFxenonlevel was significantly influenced by the PaCO2as well as by the anesthetic used. At normocapnia, patients anesthetized with halothane had a mean CBFxenonof 40 plus/minus 3 (SE) ISI units. With isoflurane, the flow was significantly (P < 0.01, 33 plus/minus 3 ISI units) less than with halothane. Hypocapnia decreased mean CBFxenon(P < 0.0001) during both anesthetics (halothane 24 plus/minus 3, isoflurane 13 plus/minus 2 ISI units). The effects on CBFxenon, between the anesthetics, differed significantly (P < 0.01) also during hypocapnia. There were significant differences in rCBF distribution measured between the two anesthetics (P < 0.05). During isoflurane anesthesia, there was a relative increase in flow values in subcortical regions (thalamus and basal ganglia) to 10–15%, and in pons to 7–10% above average. Halothane, in contrast, induced the highest relative flow levels in the occipital lobes, which increased by approximately 10% above average. The rCBF level was increased approximately 10% in cerebellum with both anesthetics. Changes in PaCO2did not alter the rCBF distribution significantly.ConclusionsThere is a difference in the human rCBF distribution between halothane and isoflurane with higher relative flows in subcortical regions during isoflurane anesthesia. However, despite this redistribution, isoflurane anesthesia resulted in a lower mean CBFxenonthan did anesthesia with halothane.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundHospitalized patients outside of the operating room frequently require emergency airway management. This study investigates complications of emergency airway management in critically ill adults, including: (1) the incidence of difficult and failed intubation; (2) the frequency of esophageal intubation; (3) the incidence of pneumothorax and pulmonary aspiration; (4) the hemodynamic consequences of emergent intubation, including death, during and immediately following intubation; and (5) the relationship, if any, between the occurrence of complications and supervision of the intubation by an attending physician.MethodsData were collected on consecutive tracheal intubations carried out by the intensive care unit team over a 10‐month period. Non‐anesthesia residents were supervised by anesthesia residents, critical care attending physicians, or anesthesia attending physicians.ResultsTwo hundred ninety‐seven consecutive intubations were carried out in 238 adult patients. Translaryngeal tracheal intubation was accomplished in all patients. Intubation was difficult in 8% of cases (requiring more than two attempts at laryngoscopy by a physician skilled in airway management). Esophageal intubation occurred in 25 (8%) of the attempts but all were recognized before any adverse sequelae resulted. New infiltrates suggestive of pulmonary aspiration were present on chest radiograph after 4% of intubations. Seven patients (3%) died during or within 30 min of the procedure. Five of the seven patients had systemic hypotension (systolic blood pressure less or equal to 90 mmHg), and four of the five were receiving vasopressors to support systolic blood pressure. Patients with systolic hypotension were more likely to die after intubation than were normotensive patients (P < 0.001). There was no relationship between supervision by an attending physician and the occurrence of complications.ConclusionsIn critically ill patients, emergency tracheal intubation is associated with a significant frequency of major complications. In this study, complications were not increased when intubations were accomplished without the supervision of an attending physician as long as the intubation was carried out or supervised by an individual skilled in airway management. Mortality associated with emergent tracheal intubation is highest in patients who are hemodynamically unstable and receiving vasopressor therapy before intubation.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundThe benefit of epidural versus intravenous fentanyl administration for postoperative analgesia is controversial. In the current study, the intraoperative effects of epidural versus intravenous fentanyl administration were compared during major surgery.MethodsTwenty elective patients scheduled for thoracoabdominal esophagectomy under general anesthesia with propofol infusion were randomly allocated to receive either intravenous or epidural boluses of 50–100 micro gram fentanyl in a double‐blind fashion to maintain hemodynamic stability. Plasma cortisol and fentanyl, as well as total urinary catecholamines, were obtained at the end of the operations.ResultsHemodynamic variations were similar except that patients receiving epidural fentanyl had a lower incidence of heart rate reduction (> 20% reduction from baseline, P < 0.05). There were no differences in mean intraoperative fentanyl (1,115 + 430 and 1,010 + 377 micro gram, epidural and intravenous, respectively) or propofol (2,281 + 645 and 2,452 + 1,169 mg) doses, number of boluses of fentanyl (nine in both groups), plasma fentanyl concentration (1.13 plus/minus 0.4 and 1.02 plus/minus 0.46 ng/ml), or number of anesthesiologists correctly identifying the site of fentanyl administration. Similarly, there were no differences in plasma glucose (8.9 + 1.8 and 9.3 + 1.8 mM) and cortisol (696 + 446 and 846 + 257 mM), or urinary epinephrine (12 + 3.7 and 13.1 + 9.2, micro gram/sample) and norepinephrine (42.7 plus/minus 26.7 and 39.1 plus/minus 2.76, micro gram/sample).ConclusionsThere appears to be no clinical advantage to epidural administration of fentanyl over intravenous administration during anesthesia for major surgery.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundProphylactic administration of the antifibrinolytic drug tranexamic acid decreases bleeding and transfusions after cardiac operations. However, the best dose of tranexamic acid for this purpose remains unknown. This study explored the dose‐response relationship of tranexamic acid for hemostatic efficacy after cardiac operation.MethodsIn prospective, randomized, double‐blinded fashion, 148 patients undergoing cardiac operation with extracorporeal circulation were divided into six groups: a placebo group and five groups receiving tranexamic acid in loading doses before incision (range 2.5 to 40 mg *symbol* kg sup ‐1) and one‐tenth the loading dose hourly for 12 h. The mass of blood collected by chest tubes over 12 h represented blood loss. Allogeneic transfusions within 12 h and within 5 d of surgery were tallied.ResultsThe six groups presented similar demographics. Patients receiving placebo had increased postoperative D‐dimer concentration compared to groups receiving tranexamic acid. Patients receiving at least 10 mg *symbol* kg sup ‐1 tranexamic acid followed by 1 mg *symbol* kg sup ‐1 *symbol* h sup ‐1 bled significantly less (365, 344, and 369 g *symbol* 12 h sup ‐1, respectively, for those three groups) compared with patients who received placebo (522 g, P < 0.05). Tranexamic dose did not affect transfusions. Only initial hematocrit affected whether a patient received an allogeneic transfusion within 5 days of operation (odds ratio 2.08 for each 3% absolute decrease in hematocrit).ConclusionsProphylactic tranexamic acid, 10 mg *symbol* kg1followed by 1 mg *symbol* kg sup ‐1 *symbol* h sup ‐1, decreases bleeding after extracorporeal circulation. Larger doses do not provide additional hemostatic benefit.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID

摘要:

BackgroundAlthough the effects of propofol on cerebral metabolism have been studied in animals, these effects have yet to be directly examined in humans. Consequently, we used positron emission tomography (PET) to demonstrate in vivo the regional cerebral metabolic changes that occur in humans during propofol anesthesia.MethodsSix volunteers each underwent two PET scans; one scan assessed awake‐baseline metabolism, and the other assessed metabolism during anesthesia with a propofol infusion titrated to the point of unresponsiveness (mean rate + SD 7.8 + 1.5 mg *symbol* kg1*symbol* h1). Scans were obtained using the18fluorodeoxyglucose technique.ResultsAwake whole‐brain glucose metabolic rates (GMR) averaged 29 + 8 micro moles *symbol* 100 g1*symbol* min1(mean plus/minus SD). Anesthetized whole‐brain GMR averaged 13 + 4 micro moles *symbol* 100 g1*symbol* min1(paired t test, P < 0.007). GMR decreased in all measured areas during anesthesia. However, the decrease in GMR was not uniform. Cortical metabolism was depressed 58%, whereas subcortical metabolism was depressed 48% (P < 0.001). Marked differences within cortical regions also occurred. In the medial and subcortical regions, the largest percent decreases occurred in the left anterior cingulate and the inferior colliculus.ConclusionPropofol produced a global metabolic depression on the human central nervous system. The metabolic pattern evident during anesthesia was reproducible and differed from that seen in the awake condition. These findings are consistent with those from previous animal studies and suggest PET may be useful for investigating the mechanisms of anesthesia in humans.

ISSN:0003-3022    

出版商:OVID    

年代:1995

数据来源: OVID