Impact of intraoperative blood salvage on monocyte subsets alteration and intracellular tumor necrosis factor-α production.

Intraoperative salvaged blood is used to reduce allogeneic blood transfusion in orthopedic surgery patients. However, salvaged blood reinfusion may lead to immune reactions. Salvaged and venous blood from 20 patients undergoing hip arthroplasty was processed. The salvaged samples were mixed with patients' venous blood and incubated in absence or presence of lipopolysaccharide. SAMPLES: Venous: venous patient blood (n = 20). Native: mixed salvaged native blood (n = 20). Filtered: mixed salvaged leukocyte filtered blood (n = 20). Irradiated: mixed salvaged irradiated blood (n = 20). The frequency of the surface receptors CD14, HLA-DR, and intracellular tumor necrosis factor (TNF)-α on peripheral blood mononuclear cells was analyzed by fluorescence-activated cell sorting analysis. The frequency of unstimulated CD14low and CD14high cells as well as unstimulated HLA-DR and TNF-α positive monocytes was comparable between venous and filtered salvaged blood. However, native and irradiated salvaged blood increased compared with venous (p < 0.05) and filtered salvaged blood (p < 0.05) for unstimulated CD14low cells, HLA-DR, and TNF-α positive monocytes. Stimulated intracellular TNF-α positive monocytes were decreased in native, filtered, and irradiated salvaged blood compared with venous blood (p < 0.05). Processing perioperative salvaged blood with leukofiltration minimizes the influence on monocytes activation compared with native and irradiated salvaged blood. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 815-821, 2018.

Impact of intraoperatively salvaged and washed blood on stimulated cytokine release in vitro.

BACKGROUND: Intraoperative blood salvage and processing it with commercially available devices is a widespread standard procedure to reduce allogeneic blood transfusion in patients undergoing major orthopedic surgery. The aim of this study was to investigate the impact of such processed blood on the immune system by measuring pro- and anti-inflammatory cytokines. STUDY DESIGN AND METHODS: Salvaged blood from 20 patients undergoing hip arthroplasty was processed with a continuous autotransfusion system. One part of the processed blood was left without further treatment, one part was additionally leukoreduced, one part was irradiated, and one part was separated into its cellular and soluble fraction by centrifugation. Specimens from each part were mixed in vitro with venous blood from the patient in ratios of 3:1, 1:1, and 1:3 and incubated with endotoxin for 24 hours. Tumor necrosis factor (TNF)-α and interleukin (IL)-10 were measured in cell culture supernatants by enzyme-linked immunosorbent assay. RESULTS: All parts of the salvaged blood were without a significant influence on TNF-α release. In contrast, IL-10 was significantly increased, independently of the admixtured salvaged blood being plain, additionally irradiated, or additionally leukoreduced. This IL-10 increase was also found with the cellular fraction of the plain salvaged blood, whereas the soluble fraction had no influence on IL-10 release. CONCLUSION: Intraoperative salvaged blood is not immunologically inert. We observed a significant increase in the anti-inflammatory IL-10 response without affecting the proinflammatory TNF-α release. Neither leukofiltration nor gamma irradiation eliminated this effect that was limited only to the cellular fraction of the salvaged blood, suggesting red blood cells to be responsible for the observed immunomodulation.

Randomized evaluation of the size 2 laryngeal tube and classical laryngeal mask airway in different head and neck positions in children under positive pressure ventilation.

PURPOSE: The aim of this study was to evaluate the applicability of the laryngeal tube (LT) size 2 and the classical laryngeal mask airway (LMA) size 2 in different head-neck positions under positive pressure ventilation in children by measuring leak pressures, peak pressures and the achievable tidal volumes under positive pressure ventilation. METHODS: Forty children were randomized to receive airway management by either the LT or LMA as the primary device. Leak pressures, peak pressures and tidal volumes under positive pressure ventilation were measured in the neutral, anteflection, retroversion, left-rotation and right-rotation head-neck positions. RESULTS: In all head-neck positions, the leak pressures were significantly higher for the LT than for the LMA (neutral 25.9 ± 7.0 vs. 19.1 ± 5.7 cmH2O; anteflection 29.7 ± 7.1 vs. 24.2 ± 8.9 cmH2O; retroversion 24.1 ± 7.6 vs. 17.2 ± 6.9 cmH2O). In both devices, the peak ventilation pressures were higher in the anteflection position (LT 27.1 ± 6.3 cmH2O; LMA 17.8 ± 6.7 cmH2O) than in the retroversion position (LT 13.7 ± 3.9 cmH2O; LMA 12.7 ± 3.6 cmH2O). Compared to the respirator settings, lower tidal volumes were achieved in the anteflection position (LT 65 ± 48 vs. 129 ± 38 ml, LMA 100 ± 21 vs. 125 ± 29 ml) as compared to the other positions. CONCLUSION: Based on our results, we suggest that in anaesthetized children, the size 2 LT, compared to the size 2 LMA, may be more suitable for positive pressure ventilation due to favorable leak and peak pressures. Both devices can be safely used in head-neck positions other than neutral. Most disadvantageous with regards to the measured parameters was the anteflection position, especially for the LT.

The effect of postoperative fasting on vomiting in children and their assessment of pain.

BACKGROUND: Mandatory postoperative food intake has been shown to increase nausea and vomiting, and so postoperative fasting has become common practice even if patients request food or drink. OBJECTIVE: We sought to investigate whether postoperative fasting reduces the incidence of postoperative vomiting in children when compared with a liberal regimen in which they are allowed to eat and drink upon request. METHODS: One hundred forty-seven children scheduled for outpatient surgery were randomized to one of two groups. After anesthesia, patients in the 'fasting' group were expected to fast for 6 h. The children in the 'liberal' group were allowed to eat and drink according to their own needs. The incidence of vomiting and the children's well-being were recorded at several time points over a 24-hour period. Parents were also asked to rate, on a scale of 0-6, how much their children were bothered by fasting, pain, and nausea/vomiting. RESULTS: Age (4.8 +/- 2.6 years), weight (20 +/- 9 kg) and gender (73% boys) were comparable between the groups. The incidence of vomiting was 15% in the liberal and 22% in the fasting group (P = 0.39) and, between 1 and 12 h after extubation, children in the liberal group were significantly happier (P < 0.001). Children in the liberal group were significantly less bothered by their pain than those in the fasting group (P < 0.001). CONCLUSION: Postoperative fasting did not reduce the incidence of vomiting after general anesthesia in children when compared with a liberal regimen. Furthermore, the ability to eat and drink at will decrease the bothersome aspects of pain and lead to happier patients.

Psychiatric emergencies in prehospital emergency medical systems: a prospective comparison of two urban settings.

BACKGROUND: Psychiatric emergency situations (PES) are of high importance to the German prehospital physician-based emergency medical system. So far, however, no prospective studies regarding the incidence of PES have been performed, neither have effects of training programs on diagnostic and therapeutic accuracy been studied. METHOD: The protocols of two emergency medical services (EMS) were collected and analyzed prospectively. Emergency physicians (EPs) in Kaiserslautern (KL) attended a standardized educational program and underwent daily supervision. EPs in Homburg (HOM) had not been informed about the study. In KL, sociodemographic variables were collected. An investigator who was not involved in the individual EMS mission assessed the correct classification of PES. RESULTS: Among all calls for an EP, 11.8% were classified as PES. There was no difference between the two centers. Correct classification of PES in KL was significantly higher than that in HOM (94.3% vs. 80.6%). Documentation of suicidal behavior was deficient in both centers. EPs in KL gave verbal crisis intervention significantly more often, administered less medication overall, and dispensed more specific drugs in psychotic disorders and significantly less drugs in substance abuse disorders. Patients were more often treated at the scene and were less often transported to a hospital. Some sociodemographic variables were associated with psychiatric morbidity of treatment. CONCLUSION: Accounting for 12% of all missions, psychiatric emergencies are a frequent reason for calls for EPs, equaling trauma-related and neurological emergencies. The most frequent reasons for calls were alcohol intoxication, states of agitation and suicidal behavior. The diagnostic and therapeutic accuracy of EPs may be improved with a concise standardized teaching program.

Comparative pharmacodynamic modeling using bispectral and narcotrend-index with and without a pharmacodynamic plateau during sevoflurane anesthesia.

BACKGROUND: We compared two pharmacodynamic models, one with and one without a plateau effect. Bispectral indices (BIS, Aspect Medical Systems, Natick, MA, version XP) and Narcotrend (NCT, MonitorTechnik, Bad Bramstedt, Germany, version 4.0) were used as an electroencephalographic measure of sevoflurane drug effect. In addition, we tried to analyze the origin of the plateau. METHODS: We investigated 26 adult patients scheduled for radical prostatectomy. At least 45 min after induction of general anesthesia, end-tidal sevoflurane concentrations were varied between 1 vol% and 4 vol%. To evaluate the relationship between concentrations and electroencephalographic indices, two different pharmacodynamic models were applied: a conventional model based on a single sigmoidal curve, and a novel model based on two sigmoidal curves for BIS and NCT values with and without burst suppression. The parameters of the models were estimated by NONMEM V (GloboMax, Hanover) by minimizing log likelihood. Statistical significance between the two models was calculated by the likelihood ratio test. RESULTS: The end-tidal sevoflurane concentration ranged from 1.04 +/- 0.17 vol% to 4.43 +/- 0.43 vol%. The difference between the log likelihood values of the new pharmacokinetic/pharmacodynamic model with two connected sigmoidal curves and the classical E(max) model with one sigmoidal curve is 396 (P < 0.001) for the BIS monitor and 1121 (P < 0.001) for the NCT. The plateau is positioned at the change between the maximum delta power and the increase of burst suppression ratio. CONCLUSION: A pharmacokinetic/pharmacodynamic model consisting of two sigmoid curves with an intervening plateau describes the effect of sevoflurane on BIS and NCT indices better than a model with a single sigmoid curve.

The efficacy of the non-opioid analgesics parecoxib, paracetamol and metamizol for postoperative pain relief after lumbar microdiscectomy.

In this prospective, double-blind, randomized, placebo-controlled study we compared the efficacy of three IV non-opioid analgesics for postoperative pain relief after lumbar microdiscectomy. Eighty healthy patients were randomly divided into 4 treatment groups (n = 20 each) to receive either parecoxib 40 mg, paracetamol 1 g, metamizol 1 g, or placebo IV 45 min before the end of surgery. In the postanesthesia care unit (PACU) patients were treated using patient-controlled analgesia (PCA) with piritramide. In the metamizol group the pain score at arrival in the PACU was significantly lower compared with the paracetamol, parecoxib, and placebo groups. In addition, in the metamizol group significantly fewer patients required additional PCA compared with the other groups studied. However, in those patients who required additional pain therapy in the four treatment groups, there was no significant difference in time to first request for piritramide and cumulative consumption of piritramide as assessed by the PCA data in the PACU. The incidence of adverse side effects was infrequent in all groups. These results suggest that in patients undergoing lumbar microdiscectomy, metamizol is superior to parecoxib, paracetamol, and placebo for immediate postoperative pain relief with minimal side effects.

Prospective application of a simplified risk score to prevent postoperative nausea and vomiting.

PURPOSE: To compare the risk-adapted approach with ondansetron against ondansetron plus dexamethasone to prevent postoperative nausea and vomiting (PONV) in a randomized clinical trial. METHODS: 460 patients scheduled for elective surgery were enrolled in this prospective study and stratified according to a simplified risk score for PONV. Patients having no or one risk factor were considered at low risk (group L) and did not receive study medication. Those with two to four risk factors were considered high risk and were randomized to receive 4 mg ondansetron plus placebo (group H-O) or 4 mg ondansetron plus 8 mg dexamethasone (group H-OD). Incidence and intensity of PONV were observed for 24 hr after surgery. Data were analyzed with Fisher's exact or Student's t tests; P < 0.05 was considered statistically significant. RESULTS: The incidence of PONV was 9% in group L (n = 87), 31% in those receiving ondansetron (group H-O, n = 185), and 22% in those receiving both drugs (group H-OD, n = 181). The incidence of PONV was significantly smaller in both high-risk groups than predicted without treatment (P < 0.001). While the incidence of PONV failed statistical significance between the two intervention groups (P = 0.08), the mean number of episodes of PONV and the mean maximal intensity of each episode of PONV were lower in group H-OD (P = 0.03 and P = 0.01, respectively). Patients of group H-OD required less antiemetic rescue therapy (P = 0.004). CONCLUSIONS: Ondansetron plus dexamethasone prevents PONV more effectively than ondansetron alone in patients at high risk for PONV.

A factorial trial of six interventions for the prevention of postoperative nausea and vomiting.

BACKGROUND: Untreated, one third of patients who undergo surgery will have postoperative nausea and vomiting. Although many trials have been conducted, the relative benefits of prophylactic antiemetic interventions given alone or in combination remain unknown. METHODS: We enrolled 5199 patients at high risk for postoperative nausea and vomiting in a randomized, controlled trial of factorial design that was powered to evaluate interactions among as many as three antiemetic interventions. Of these patients, 4123 were randomly assigned to 1 of 64 possible combinations of six prophylactic interventions: 4 mg of ondansetron or no ondansetron; 4 mg of dexamethasone or no dexamethasone; 1.25 mg of droperidol or no droperidol; propofol or a volatile anesthetic; nitrogen or nitrous oxide; and remifentanil or fentanyl. The remaining patients were randomly assigned with respect to the first four interventions. The primary outcome was nausea and vomiting within 24 hours after surgery, which was evaluated blindly. RESULTS: Ondansetron, dexamethasone, and droperidol each reduced the risk of postoperative nausea and vomiting by about 26 percent. Propofol reduced the risk by 19 percent, and nitrogen by 12 percent; the risk reduction with both of these agents (i.e., total intravenous anesthesia) was thus similar to that observed with each of the antiemetics. All the interventions acted independently of one another and independently of the patients' baseline risk. Consequently, the relative risks associated with the combined interventions could be estimated by multiplying the relative risks associated with each intervention. Absolute risk reduction, though, was a critical function of patients' baseline risk. CONCLUSIONS: Because antiemetic interventions are similarly effective and act independently, the safest or least expensive should be used first. Prophylaxis is rarely warranted in low-risk patients, moderate-risk patients may benefit from a single intervention, and multiple interventions should be reserved for high-risk patients.

A risk adapted approach reduces the overall institutional incidence of postoperative nausea and vomiting.

PURPOSE: Routine prophylactic antiemetic treatment of surgical patients appears justified only in case of an increased risk of postoperative nausea and vomiting (PONV). The objective of this investigation was to assess the feasibility and efficacy of a dichotomized risk score adapted management of PONV based on ondansetron prophylaxis and treatment with respect to the overall institutional rate of PONV. METHODS: After estimating the individual PONV risk by a simplified score, 162 adult patients scheduled for elective surgery received either 4 mg ondansetron intravenously (two to four risk factors = high-risk) or no prophylaxis (zero to one risk factor = low-risk). For antiemetic treatment ondansetron was given intravenously and orally. Incidence of PONV was recorded during the first 24 hr after recovery. RESULTS: Data from 159 subjects were analyzed with 44 patients classified as low-risk and 115 patients classified as high-risk. Nine low-risk and 58 high-risk patients experienced PONV. The expected institutional PONV incidence of 47% was reduced to 36%. Treatment with ondansetron was necessary in seven low-risk and 37 high-risk patients with a complete response rate of 71% (low-risk) and 43% (high-risk). CONCLUSION: Providing antiemetic prophylaxis with ondansetron to high-risk patients strictly based on a simplified risk score can reduce the overall institutional rate of PONV. However, classifying patients into two groups while using ondansetron as the single antiemetic in the high-risk group appears to be of limited efficacy as the incidence of PONV in high-risk patients is still double that of low-risk patients.

An international multicenter protocol to assess the single and combined benefits of antiemetic interventions in a controlled clinical trial of a 2x2x2x2x2x2 factorial design (IMPACT).

For various diseases clinicians have to combine different drugs or interventions when a single drug or intervention does not lead to satisfactory results. However, quantifying the relative benefit of certain drugs or interventions when given alone and in combination under controlled conditions requires a complex factorial design. This paper describes such a method applied to a large multicenter trial for the prevention of postoperative nausea and vomiting (PONV), which may be of great interest for other specialties. Approximately 28 million operations are performed annually in the United States, mainly under general anesthesia with volatile anesthetics. Unfortunately, one-third of these patients suffer from PONV. This prompted extensive research of antiemetic and anesthetic drugs, but none of the interventions appeared to satisfactorily prevent PONV. Scuderi et al. were the first to almost eliminate PONV by combining various antiemetic interventions; however, the relative benefit of each intervention remained unclear. Accordingly, we have designed a large randomized controlled trial studying six different antiemetic interventions-three involving use of various antiemetic drugs and three involving choice of anesthetic drugs-to answer the following main questions: (1) What is the relative benefit of each of the antiemetic intervention? (2) Are certain combinations of antiemetic interventions more effective than others? Using a complete factorial design this leads to 2(3)=8 antiemetic combinations, which multiply with the 2(3)=8 combinations of anesthetic drugs, leading to a total of 2(6)=64 possible combinations. The six factors are the antiemetics ondansetron (versus control), dexamethasone (versus control), droperidol (versus control), and the intravenous anesthetic propofol (versus volatile anesthetics), air (versus nitrous oxide), and remifentanil (versus fentanyl). The primary outcome is freedom from PONV within the first 24 hours after anesthesia. Eligible patients are adults scheduled for elective surgery under general anesthesia with an increased risk for PONV so that the expected incidence in the control group (with none of the six antiemetic interventions) is approximately 60%. In order to allow analyses for up to three factor interactions, a sample size was estimated to be in the range of approximately 5000 patients. To the best of our knowledge this is the first randomized controlled trial of a six-way factorial design that may serve as an example for numerous other medical specialties.

Accuracy of portable quantitative capnometers and capnographs under prehospital conditions.

This study was designed to assess the pCO(2) accuracy of portable mainstream (Tidal Wave, Novametrix; Propaq 106, Protocol) and sidestream capnometers (Capnocheck 8200, BCI; Capnocount mini, Weinmann; NPB-75, Nellcor Puritan Bennett; SC-210, Pryon) with respect to international standards and preclinical emergency conditions. Measurements were performed under temperature conditions of +22 degrees C and -20 degrees C using dry gas mixtures with different CO(2) concentrations (STPD) and in patients ventilated with pure oxygen (BTPS). Accuracy presented to be between +1% (Capnocheck) and +12% (Propaq) (STPD) and between -0.4% (Capnocheck) and +11% (Tidal Wave) (BTPS). The measurements were affected by low ambient temperature only in the NPB-75 (+15%). Our results indicate that portable quantitative capnometers are able to fulfill accuracy requirements as requested by international standards but can be affected by changing ambient temperatures.

Narcotrend monitoring allows faster emergence and a reduction of drug consumption in propofol-remifentanil anesthesia.

BACKGROUND: The 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. METHODS: With 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(R), or solely by clinical parameters. Anesthesia was induced with 0.4 micro x kg-1 x min-1 remifentanil and a propofol target-controlled infusion at 3.5 microg/ml. After intubation, remifentanil was reduced to 0.2 micro x kg-1 x min-1, whereas the propofol infusion was adjusted according to clinical parameters or to the following target values: during maintenance to D(0) (Narcotrend) or 50 (BIS); 15 min before the end of surgery to C(1) (Narcotrend) or 60 (BIS). Recovery times were recorded by a blinded investigator, and average normalized propofol consumption was calculated from induction and maintenance doses. RESULTS: The 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 x kg-1 x h-1 vs. Narcotrend, 4.5 +/- 1.1 mg x kg-1 x h-1 or BIS(R), 4.8 +/- 1.0 mg x kg-1 x h-1; P < 0.001), opened their eyes earlier (9.3 +/- 5.2 vs. 3.4 +/- 2.2 or 3.5 +/- 2.9 min), and were extubated sooner (9.7 +/- 5.3 vs. 3.7 +/- 2.2 or 4.1 +/- 2.9 min). CONCLUSIONS: The 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.

Postoperative myalgia after succinylcholine: no evidence for an inflammatory origin.

UNLABELLED: A common side effect associated with succinylcholine is postoperative myalgia. The pathogenesis of this myalgia is still unclear; inflammation has been suggested but without convincing evidence. We designed the present study to investigate whether an inflammatory reaction contributes to this myalgia. The incidence and severity of succinylcholine-associated myalgia was determined in 64 patients pretreated with saline or dexamethasone before succinylcholine (n = 32 for each). Incidence and severity of myalgia did not differ significantly between the two groups: 15 patients in the dexamethasone group complained of myalgia compared with 18 patients in the saline group, and severe myalgia was reported by five patients and three patients, respectively (not significant). At 48 h after surgery, 12 patients in both groups still suffered from myalgia (not significant). In addition, interleukin-6 (IL-6) as an early marker of inflammation was assessed in a subgroup of 10 patients pretreated with saline. We found an increase of IL-6 for only three patients, but only one patient reported myalgia; no relationship between myalgia and the increase of IL-6 was found. In conclusion, there is no evidence for an inflammatory origin of succinylcholine-associated myalgia. IMPLICATIONS: Administration of dexamethasone before succinylcholine was not effective in decreasing the incidence or the severity of succinylcholine-induced postoperative myalgia. Furthermore, there was no significant relationship between postoperative myalgia and time course of interleukin-6 concentrations, a marker of inflammation. Pretreatment with dexamethasone is not justified to prevent postoperative myalgia after succinylcholine.

Impact of alloantigens and storage-associated factors on stimulated cytokine response in an in vitro model of blood transfusion.

BACKGROUND: Transfusion of blood may contribute to immunosuppression in major surgery. The authors assessed the impact of alloantigens and storage on function of peripheral blood mononuclear cells cultured in their physiologic environment. METHODS: Blood units (whole blood, packed erythrocytes) were prepared with or without prestorage leukodepletion and stored for 24-26 days. Blood samples were coincubated with allogeneic fresh blood, autologous, or allogeneic stored blood. Endotoxin-stimulated release of tumor necrosis factor-alpha (TNF-alpha) and interleukin 10 (IL-10) was measured after 24 h of culture by enzyme-linked immunosorbent assay. RESULTS: Coincubation with equal amounts of allogeneic fresh blood showed almost no influence on TNF-alpha (-12%, not significant) and IL-10 (+11%, not significant) release. Stored allogeneic whole blood resulted in a significant TNF-alpha depression (-61%) and IL-10 induction (+221%). These effects were diminished but not prevented by prestorage leukodepletion (TNF-alpha -42%, IL-10 +110%) and required the presence of soluble factors (TNF-alpha suppression) and cellular components (IL-10 induction). TNF-alpha decrease and IL-10 increase were in the same order of magnitude (-40%, +134% with, -65%, +314% without leukodepletion) after coincubation with autologous blood. In contrast, allogeneic erythrocytes had only little effects (TNF-alpha -6%, IL-10 +36%) even at this high transfusion equivalent. CONCLUSION: These data suggest that banked whole blood has an immunosuppressive effect that is largely attributable to storage-dependent factors. These factors are partially removed by prestorage leukodepletion, while the contribution of alloantigens is of minor significance. Immunosuppressive effects are least apparent with leukodepleted erythrocytes, suggesting that the presence of plasma during storage is required for the immunosuppressive effect to develop.

General anesthesia versus monitored anesthesia care with remifentanil for assisted reproductive technologies: effect on pregnancy rate.

STUDY OBJECTIVES: To compare the outcome of assisted reproductive technology procedures in women who undergo monitored anesthesia care (MAC) with remifentanil versus general anesthesia. DESIGN: Retrospective data analysis. SETTING: University hospital. PATIENTS: 251 ASA physical status I and II women participating in an in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI) program. INTERVENTIONS: During the first phase of the study, all patients underwent general anesthesia induction with alfentanil, propofol, and nitrous oxide, which was maintained with isoflurane or propofol infusion. In the second phase of the study, all patients received a standardized MAC technique with a remifentanil infusion; local anesthetics were not used. MEASUREMENTS: The primary endpoint was pregnancy rate per transfer. The number of oocytes collected, fertilized, and cleaved was recorded, as was the number of oocytes transferred. MAIN RESULTS: Patients who underwent MAC had a greater pregnancy rate with IVF (28.2 vs. 16.3%), with ICSI (32.2% vs. 18.8%), and overall (30.6% vs. 17.9%). CONCLUSIONS: Pregnancy rates in women undergoing transvaginal oocyte retrieval for assisted reproductive technologies were significantly higher with a remifentanil-based MAC technique than with a general anesthetic technique.