Conscious sedation and analgesia for oocyte retrieval during IVF procedures: a Cochrane review

Anaesthesia considerations for assisted reproductive technology: a focused review

The global burden of infertility is significant and the evidence suggests it is increasing in prevalence worldwide. Assisted reproductive technologies (ARTs) are fertility related treatments used to achieve pregnancy which involve the manipulation of both oocytes and sperm. The specialty is rapidly growing and anaesthesia may be required for several stages in the ART cycle. Anaesthesiologists should appreciate the processes involved and how anaesthesia care can influence safe and effective treatment outcomes. In this review article we explain the key steps of the ART cycle and the role of anaesthesiologists in this process. We also highlight key patient considerations, the implications of remote site anaesthesia and the safety concerns with provision of sedation by non-anaesthesiologists. Finally we outline a typical anaesthetic technique used in our institution for transvaginal oocyte retrieval.

Comparison of a Reduced Needle With a Thin Tip and a Standard Thin Needle (Same Width Overall) for Oocyte Retrieval

INTRODUCTION

At our facility, oocyte retrieval had previously been performed with a 20-gauge standard needle that is uniformly thin overall (tSN); but recently, we have instead started using reduced needles, with a 20-gauge tip and 17-gauge body (RN). Until now, there have been comparisons between RN and thick standard needles, but there have been no comparisons between RN and tSN. The purpose of this study was to compare oocyte retrieval outcomes using RN with tSN.

METHODOLOGY

 Information on oocyte retrieval was extracted from the medical records of 304 cycles performed at our facility from January 2020 to December 2023. The oocyte retrieval outcomes of the two types of needles were compared retrospectively with respect to age, anti-Müllerian hormone (AMH), procedure time, additional sedatives, number of follicles punctured, number of oocytes retrieved, number of oocytes fertilized, oocyte recovery rate, and fertilization rate.

RESULTS

When AMH ≥ 1.2 ng/mL, the procedure time was 9.3 ± 3.7 and 12.1 ± 4.6 minutes in the RN and tSN groups, respectively (P < 0.001), and the need for additional sedatives was also significantly different: 54.0% in the RN group and 78.5% in the tSN group (P = 0.002). The oocyte recovery rate was significantly different between the RN and tSN groups at 65.3% and 61.2%, respectively (P = 0.046), and the fertilization rate was significantly different between the RN and tSN groups at 56.8% and 66.8%, respectively (P < 0.001). There were no significant differences by age, AMH, number of follicles punctured, number of oocytes retrieved, or number of oocytes fertilized.

CONCLUSIONS

Without diminished ovarian reserve, RN reduced procedure time and the need for additional sedatives compared to tSN. In addition, the number of oocytes fertilized per oocyte retrieval remained the same, indicating that oocyte retrieval performance was not affected.

Effects of Propofol versus Sevoflurane on Postoperative Pain and Neuroendocrine Stress Response in Oocyte Pickup Patients

Background

Pain aggravates the autonomic response to stress and raises neuroendocrine stress hormone levels. We compared the effects of propofol and sevoflurane on postoperative pain and neuroendocrine stress hormones. A prospective, randomized, and controlled trial was conducted with 60 patients.

Methods

We randomly allocated patients to groups P (remifentanil/propofol, n = 30) and S (remifentanil/sevoflurane, n = 30). Preoperative blood samples were taken to measure serum adrenocorticotropic hormone (ACTH), corticotropin-releasing hormone (CRH), glucagon, cortisol, aldosterone, and prostaglandin E2 (PGE2) levels. Intraoperatively and postoperatively, clinical parameters were monitored at different time points. The hormone levels were again measured in the follicular fluid and blood postoperatively.

Result

Demographic data were similar. The preoperative serum aldosterone levels were significantly higher in group P (p=0.001). Preoperative and postoperative serum ACTH, glucagon, cortisol, and PGE2 levels were significantly different in group P (p=0.009, p=0.004, p=0.029, and p=0.002); serum ACTH, glucagon, and PGE2 levels increased while serum cortisol levels decreased postoperatively. In group S, serum CRH and aldosterone levels, both increased in the postoperative period compared to the preoperative (p=0.001, p=0.006). Postoperatively, glucagon and PGE2 levels were both higher in group P than group S (p=0.019, p=0.015). In postoperative follicular fluid, glucagon and PGE2 levels were higher in group P, while cortisol levels were higher in group S (p=0.001, p=0.007, and p=0.001).

Conclusion

The effects of anesthetic agents were different. In group P, in the preoperative and postoperative evaluation, ACTH, glucagon, and PGE2 increased postoperatively, while cortisol decreased. In group S, aldosterone and CRH increased postoperatively. Glucagon and PG E2 were higher in group P than S, postoperatively.

Effects of music therapy on pain and oxidative stress in oocyte pick-up: A randomized clinical trial

Background and objective

The aim was to investigate the effects of Turkish classical music on pain and oxidative stress in patients undergoing oocyte pick-up.

Methods

The study was a randomized, controlled trial. The groups included Group NM (Non-Music), control group; Group PM, which comprised patients who listened to music before the operation; and Group CM, which comprised patients who listened to music both before and during the operation. Blood was drawn prior to the operation to measure the oxidative stress values. Pain, hemodynamic parameters, oxidative stress values were assessed postoperatively.

Results

The number of patients requiring additional propofol was higher in Group PM than in Groups NM and CM (p = 0.003). The postoperative Visual Analog Scale (VAS) score were lower in Groups PM and CM than in Group NM (p = 0.001, p = 0.007) in the 1st and 60th minutes. The postoperative VAS score was lower in Group CM than in Group NM (p = 0.045) in the 5th minute. The postoperative additional analgesic requirements were lower in Groups PM and CM than in Group NM (p = 0.045). The postoperative blood glutathione peroxidase values were significantly higher in Groups PM and CM than in Group NM (p = 0.001). The postoperative catalase values were significantly higher in Groups PM and CM than in Group NM (p = 0.008 and p < 0.001). The preoperative malondialdehyde values were significantly lower in Groups PM and CM than in Group NM. The preoperative nitric oxide values were higher in Groups PM and CM than in Group NM (p < 0.001), whereas the postoperative nitric oxide values were lower in Groups PM and CM than in Group NM (p < 0.001).

Conclusion

Turkish classical music has beneficial effects on pain and oxidative stress in oocyte pick-up patients.

[Effects of music therapy on pain and oxidative stress in oocyte pick-up: a randomized clinical trial]

BACKGROUND AND OBJECTIVE

The aim was to investigate the effects of Turkish classical music on pain and oxidative stress in patients undergoing oocyte pick-up.

METHODS

The study was a randomized, controlled trial. The groups included were Group NM (Non-Music), control group; Group PM, which comprised patients who listened to music before the operation; and Group CM, which comprised patients who listened to music both before and during the operation. Blood was drawn prior to the operation to measure the oxidative stress values. Pain, hemodynamic parameters, oxidative stress values were assessed postoperatively.

RESULTS

The number of patients requiring additional propofol was higher in Group PM than in Groups NM and CM (p=0.003). The postoperative Visual Analog Scale (VAS) score were lower in Groups PM and CM than in Group NM (p=0.001, p=0.007) in the 1^st and 60^th minutes. The postoperative VAS score was lower in Group CM than in Group NM (p=0.045) in the 5^th minute. The postoperative additional analgesic requirements were lower in Groups PM and CM than in Group NM (p=0.045). The postoperative blood glutathione peroxidase values were significantly higher in Groups PM and CM than in Group NM (p=0.001). The postoperative catalase values were significantly higher in Groups PM and CM than in Group NM (p=0.008 and p ≤0.001). The preoperative malondialdehyde values were significantly lower in Groups PM and CM than in Group NM. The preoperative nitric oxide values were higher in Groups PM and CM than in Group NM (p ≤0.001), whereas the postoperative nitric oxide values were lower in Groups PM and CM than in Group NM (p ≤0.001).

CONCLUSION

Turkish classical music has beneficial effects on pain and oxidative stress in oocyte pick-up patients.

High level of satisfaction among women who underwent oocyte retrieval without anesthesia

OBJECTIVE

To assess the level of satisfaction of women undergoing transvaginal oocyte retrieval (TOR) without anesthesia as well as the comfort of the gynecologists.

DESIGN

Single-center, prospective cohort study of women undergoing TOR from July 2017 to January 2018.

SETTING

This study was conducted in an academic public hospital.

PATIENT(S)

Women with ≤15 follicles for retrieval were eligible. Women with body mass index > 35, difficult vaginal approach, endometrioma > 5 cm, or pelvic inflammatory disease were excluded.

INTERVENTION(S)

None.

MAIN OUTCOME MEASURE(S)

Our primary endpoint was patient satisfaction. Secondary endpoints were women's willingness to recommend or undergo the procedure again without anesthesia, anxiety levels before the procedure, expected level of pain, actual pain levels during the procedure, and gynecologist's level of difficulty or technical compromise.

RESULT(S)

During the study period, 500 TORs were performed, of which 402 (80%) were screened for study eligibility. Overall, data were analyzed for 50 eligible women who had their first in vitro fertilization cycle (participating in the study) without anesthesia. High rates of satisfaction were reported, and 90% would recommend the procedure without anesthesia to their friends. Physicians graded the difficulty of the procedure as very easy in 35 procedures; in only two procedures was difficulty reported.

CONCLUSION(S)

TOR without anesthesia is feasible, with a relatively high satisfaction rate from both patients and gynecologists, suggesting that it should be considered in selected women.

Anesthesia and analgesia for transvaginal oocyte retrieval. Should we recommend or avoid any anesthetic drug or technique?

PURPOSE OF REVIEW

The objective of this review is to analyze and summarize the current anesthetic methods used to alleviate pain and discomfort during transvaginal oocyte retrieval procedures (TORP), to try to reach practical recommendations, based on the evidence, which will translate into daily practice, the knowledge on the anesthetic management of patients scheduled for TORP.

RECENT FINDINGS

There is no strong evidence to recommend the avoidance of any technique or drug for TORP, including nitrous oxide or halogenated agents. Women should be offered any available technique. The evidence available up to date is not convincing enough to recommend avoiding any anesthetic technique in terms of pregnancy and birth rates.

SUMMARY

TORP is painful for women and different techniques may be used for pain relief in day case surgery. The other important outcome to consider is the pregnancy rate, and any anesthetic technique or drug which would improve this pregnancy rate should be recommended. Conscious sedation and general anesthesia proved to be well tolerated for woman and the oocytes, despite the use of propofol, opioids, benzodiacepines, nitrous oxide, or other drugs. Spinal anesthesia and paracervical block are also acceptable options, and can be combined with conscious sedation. Nevertheless, more studies are needed to find out the ideal drug or technique combination for the woman and the oocyte.

Hemodynamic parameters and reproductive outcome after intracytoplasmic sperm injection and fresh embryo transfer in patients undergoing oocyte retrieval with general anesthesia using fentanyl, remifentanil or alfentanil - A randomized clinical trial

OBJECTIVE

Anesthesia for assisted reproductive technology is very important to provide less stressful and painful environment for patients, with minimal side effects on oocytes. In the present study, we aimed to evaluate hemodynamic parameters, recovery time and intracytoplasmic sperm injection (ICSI) outcome among patients underwent anesthesia with fentanyl, remifentanil or alfentanil.

MATERIAL AND METHODS

This randomized double-blinded clinical trial was conducted in patients undergoing anesthesia for transvaginal ultrasound guided oocyte retrieval (TUGOR). Patients were randomly allocated to alfentanil (A; 15 μg/kg), fentanyl (F; 1.5 μg/kg) or remifentanil (R; 1.5 μg/kg) groups.

RESULTS

Three hundred forty patients were assessed for eligibility and randomized for transvaginal oocyte retrieval following general anesthesia and 105 were lost to follow up. No statistically significant differences were noted among groups regarding basic characteristics. Although, time to respond to verbal command was significantly different among groups (A: 1.99 ± 1.64, F: 2.56 ± 1.72, R: 1.78 ± 1.34, P = 0.014). There were no significant differences among groups with respect to the first and second postoperative pain intensity, patient satisfaction, pre-induction and post-induction systolic and diastolic blood pressure (BP). Terminal systolic (A: 101.61 ± 9.15, F: 105.29 ± 12.61, R: 102 ± 12.91, P = 0.01) and diastolic (A: 59.97 ± 9, F: 65.63 ± 9.13, R: 63.69 ± 11.01, P = 0.003) BP was significantly different among groups. The fertilization rate was significantly different among groups (A: 51.6%, F: 54.4%, R: 62.2%, P = 0.018). Implantation rate, biochemical and clinical pregnancy rate was similar among groups.

CONCLUSIONS

The results of present study demonstrated that all three opioids have the same efficiency, in regards to patient satisfaction and pregnancy outcome. However, Anesthesia with alfentanil compared with fentanyl and remifentanil, seems to be inferior for TUGOR due to higher effect on fertilization rate and less hemodynamic stability.

REGISTRATION NUMBER

IRCT201410258677N4.

Randomized double-blind clinical trial comparing two anesthetic techniques for ultrasound-guided transvaginal follicular puncture

Objective:

To compare the anesthetic techniques using propofol and fentanyl versus midazolam and remifentanil associated with a paracervical block with lidocaine in performing ultrasound-guided transvaginal oocyte aspiration.

Methods:

A randomized double-blind clinical trial (#RBR-8kqqxh) performed in 61 women submitted to assisted reproductive treatment. The patients were divided into two groups: anesthetic induction with 1mcg/kg of fentanyl associated with 1.5mg/kg of propofol (FP Group, n=32), in comparison with anesthetic induction using 0.075mg/kg of midazolam associated with 0.25mcg/kg/min of remifentanil, and paracervical block with 3mL of 2% lidocaine (MRPB Group, n=29). Main outcome measures: human reproduction outcomes, modified Aldrete-Kroulik index, hemodynamic parameters, and salivary cortisol.

Results:

The results revealed a higher number of embryos formed in the FP Group (p50=2 versus 1; p=0.025), gestation rate two times higher in the FP Group (44.4% versus 22.2%; p=0.127), less time to reach AK=10 in the MRPB Group (p50=10 versus 2; p<0.001), and lower mean of hemodynamic parameters in the MRPB Group (p<0.05).

Conclusion:

Anesthesia with fentanyl and propofol as well as with midazolam, remifentanil, and paracervical block offered satisfactory anesthetic conditions when performing assisted reproduction procedures, providing comfort for the patient and physician.

Objetivo:

Comparar as técnicas anestésicas utilizando propofol e fentanil contra midazolam e remifentanil associados a um bloqueio paracervical com lidocaína na aspiração de oócitos transvaginal guiada por ultrassom.

Métodos:

Ensaio clínico randomizado duplocego (#RBR-8kqqxh) realizado em 61 mulheres submetidas ao tratamento de reprodução assistida. As pacientes foram divididas em dois grupos: um grupo foi submetido à indução da anestesia com 1mcg/kg de fentanil associada com 1,5mg/kg de propofol (Grupo FP, n=32), em comparação com ao grupo submetido à indução da anestesia utilizando 0,075mg/kg de midazolam associada com 0,25mcg/kg/min de remifentanil, e bloqueio paracervical com 3mL de lidocaína a 2% (Grupo MRBP, n=29). Foram avaliados os resultados reprodutivos, índice modificado de Aldrete e Kroulik, parâmetros hemodinâmicos e cortisol salivar.

Resultados:

Foi encontrado um número mais elevado de embriões formados no Grupo FP (p50=2 versus 1; p=0,025), taxa de gestação duas vezes mais elevada no Grupo FP (44,4% versus 22,2%; p=0,127), menos tempo para alcançar AK=10 no Grupo MRBP (p50=10 versus 2; p<0,001) e média mais baixa de parâmetros hemodinâmicos do Grupo MRBP (p<0,05).

Conclusão:

Ambas as anestesias (com fentanil e propofol, e com midazolam, remifentanil e bloqueio paracervical) ofereceram condições anestésicas satisfatórias na realização de procedimentos realizados em reprodução assistida, proporcionando conforto para o paciente e médico.

A Prospective Randomized Trial Comparing Dexmedetomidine and Midazolam for Conscious Sedation During Oocyte Retrieval in An In Vitro Fertilization Program

Background:

Various sedative and analgesic techniques have been used for pain relief during oocyte retrieval which is the most painful part of in vitro fertilization (IVF) procedures.

Aim:

This study aimed at comparing dexmedetomidine and midazolam for conscious sedation in women undergoing transvaginal oocyte retrieval during an IVF program.

Settings and Design:

Prospective randomized double-blinded comparative study.

Patients and Methods:

Fifty-two patients undergoing oocyte retrieval in their first IVF cycle were randomly allocated into two equal groups. The intervention started with giving fentanyl1 mcg/kg intravenous (IV) followed by paracervical block in both groups. Then, subjects in group (D) received dexmedetomidine at a loading dose of 1 μg/kg IV over 10 min followed by 0.5 μg/kg/h infusion until Ramsay Sedation Scale (RSS) reached 3–4. Patients in group (M) received a loading dose of midazolam 0.06 mg/kg IV over 10 min followed by 0.5 mg incremental doses until RSS reached 3–4.

Statistical Analysis:

Statistical analysis was performed using SPSS program version 19 and EP 16 program.

Results:

Visual analog scale scores significantly decreased in group D than group M at 5 and 10 min during the procedure (P = 0.03 and 0.01, respectively), and at 20 min during postanesthesia care unit (PACU) time (P = 0.04). Intraoperative rescue sedation by propofol and postoperative rescue analgesia by acetaminophen showed a highly significant decrease (P < 0.01) in group D compared with group M. Furthermore, the time of PACU stay was significantly less (P < 0.01) in group D (49.03 ± 12.8 min) compared to group M (62.5 ± 18.34 min). Although significant bradycardia was noted in group D (23% of patients) during the procedure (P = 0.02), no cases were reported in group M. Patient satisfaction was significantly higher in group D (P < 0.1).

Conclusion:

Dexmedetomidine is an effective analgesic alternative to midazolam during oocyte retrieval for IVF. It offered not only a shorter PACU stay without significant side effects, but also better overall patient satisfaction scores.

Does Spinal Analgesia have Advantage over General Anesthesia for Achieving Success in In-Vitro Fertilization?

OBJECTIVE

Because of high psychological burden and considerable costs of in-vitro fertilization, it is greatly important to identify all factors that may influence its results. In this study, general anesthesia and spinal analgesia used for oocyte retrieval were compared in terms of success in treating infertility among couples who had undergone in-vitro fertilization at an infertility center in Tehran, Iran.

METHODS

This cohort study that was based on analysis of patient records at Mirza Kochak Khan Hospital, Tehran University of Medical Sciences, in 2008-2009. In this study, the status of chemical pregnancy among those who experienced general anesthesia or spinal anesthesia for in-vitro fertilization for the first time were compared, and the possible effects of clinical and laboratory factors using logistic regression models were considered.

RESULTS

Considering the number of transferred embryos, underlying cause of infertility and fetus grade, it was found that practicing spinal anesthesia is significantly related to increased chance of chemical pregnancy (adjusted Odds Ratio=2.07; 95% CI: 1.02,4.20; p=0.043).

CONCLUSION

According to analysis of recorded data in an infertility treatment center in Iran, it is recommended to use spinal anesthesia instead of general anesthesia for oocyte retrieval to achieve successful in-vitro fertilization outcome. This can be studied and investigated further via a proper multicentric study in the country.

Assisted reproductive techniques

Assisted reproductive technologies (ART) encompass fertility treatments, which involve manipulations of both oocyte and sperm in vitro. This chapter provides a brief overview of ART, including indications for treatment, ovarian reserve testing, selection of controlled ovarian hyperstimulation (COH) protocols, laboratory techniques of ART including in vitro fertilization (IVF), and intracytoplasmic sperm injection (ICSI), embryo transfer techniques, and luteal phase support. This chapter also discusses potential complications of ART, namely ovarian hyperstimulation syndrome (OHSS) and multiple gestations, and the perinatal outcomes of ART.

Comparison of different anaesthetic methodologies for sedation during in vitro fertilization procedures: effects on patient physiology and oocyte competence

The main goal of the present retrospective study is to compare four analgesic methodologies (EMLA cream, propofol, thiopental sodium, sevoflurane) for in vitro fertilization (IVF) oocyte retrieval. We found that most anaesthetic parameters were not significantly different among all treatments. In contrast, significant differences were revealed in all groups for total number of oocytes retrieved per patient, rate of mature oocytes at metaphase II stage (MII) and percentage of fertilization and embryo development. In the EMLA cream and thiopental sodium groups we observed the highest percentage of MII oocytes (P < 0.001). Fertilization rate in the EMLA and sevoflurane groups were similar but significantly higher than the propofol and thiopental sodium groups (P < 0.001). The highest rate of anomalous fertilization was observed in the propofol group. Rate of embryo development was similar in all groups but sevoflurane group had a lower percentage of good embryos. In conclusion, by comparing different anaesthetic techniques with different mechanisms of action and administration, potential negative effects of these drugs on the initial stages of human IVF procedure were revealed. Therefore, a local anaesthetic cream is proposed as an acceptable alternative option for anaesthesia during transvaginal oocyte retrieval.

A randomized controlled study comparing pain experience between a newly designed needle with a thin tip and a standard needle for oocyte aspiration

BACKGROUND

Ultrasound-guided transvaginal oocyte retrieval is often performed under local anaesthesia on an outpatient basis. The objective of this study was to compare the overall pain experience of a newly designed reduced needle (RN) compared with a thicker standard needle (SN).

METHODS

A prospective, randomized, multi-centre study was performed at four different clinics from June to December 2009. The oocyte aspiration was performed under local anaesthesia, either with a needle with a reduced diameter (0.9 mm) for the last 50 mm from the tip (RN) or with a SN (1.4 mm). A total of 257 patients were randomized (RN: n = 129; SN: n = 128). The primary endpoint was the overall pain experience self-assessed and registered by the patient on a visual analogue scale (VAS 0 mm = no pain to 100 mm = unbearable pain) immediately after the oocyte retrieval. Secondary end-points such as vaginal bleeding and several embryological parameters were also registered.

RESULTS

The overall pain during the oocyte retrieval procedure was significantly lower in the RN group than in the SN group (mean 21.0 mm, SD 17.5 mm and median 19.0 mm versus mean 26.0 mm, SD 19.9 mm and median 24.0 mm; P = 0.040, difference between groups mean−5.0 mm, 95% CI: 9.7 to−0.4). This was also true when adjusting for baseline characteristics such as number of follicles, number of previous oocyte pick-up, body mass index and age, by a multiple linear regression analysis. Significantly more patients (40 of 126) had less than expected vaginal bleeding in the RN group when compared with the SN group (24 of 124; 32 versus 19%; P = 0.03 and 95% CI 1.7–23.0%). No differences were found between the two needles with regard to additional i.v. analgesia, aspiration time, oocyte recovery, fertilization, cleavage rate, number of good quality embryos, number of embryos for freezing and pregnancy rate.

CONCLUSIONS

Oocyte aspiration performed with the newly designed thinner-tipped needle resulted in significantly less overall pain and less vaginal bleeding, without prolonging the retrieval procedure or influence the oocyte recovery rate, when compared with a SN.

Clinicaltrials.gov: NCT00924885

Acupuncture in clinical and experimental reproductive medicine: a review

BACKGROUND

Acupuncture has been used as treatment for infertility for hundreds of years, and recently it has been studied in male and female infertility and in assisted reproductive technologies, although its role in reproductive medicine is still debated.

AIM

To review studies on acupuncture in reproductive medicine, in experimental and clinical settings.

METHODS

Papers were retrieved on PubMed and Google Scholar and were included in the review if at least the abstract was in English.

RESULTS

There is evidence of benefit mainly when acupuncture is performed on the day of embryo transfer (ET) in the live birth rate. Benefit is also evident when acupuncture is performed for female infertility due to polycystic ovary syndrome (PCOS). There is some evidence of sperm quality improvement when acupuncture is performed on males affected by idiopathic infertility. Experimental studies suggest that acupuncture effects are mediated by changes in activity of the autonomic nervous system and stimulation of neuropeptides/neurotransmitters which may be involved in the pathogenesis of infertility.

CONCLUSIONS

Acupuncture seems to have beneficial effects on live birth rate when performed on the day of ET, and to be useful also in PCOS as well as in male idiopathic infertility, with very low incidence of side effects. However, further studies are necessary to confirm the clinical results and to expand our knowledge of the mechanisms involved.

A comparison of three different target-controlled remifentanil infusion rates during target-controlled propofol infusion for oocyte retrieval

OBJECTIVE

To evaluate the effects of three different target-controlled remifentanil infusion rates during target-controlled propofol infusion on hemodynamic parameters, pain, sedation, and recovery score during oocyte retrieval.

METHODS

Sixty-nine women were scheduled for oocyte retrieval. Target-controlled propofol infusion at an effect-site concentration of 1.5 μg/mL was instituted. The patients were randomly allocated to receive remifentanil at an effect-site concentration of either 1.5 (group I, n = 23), 2 (group II, n = 23) or 2.5 ng/mL (group III, n = 23). Hemodynamic variables, sedation, pain, the Aldrete recovery score, and side effects were recorded.

RESULTS

Hemodynamic variables, sedation and pain scores and the number of patients with the maximum Aldrete recovery score 10 min after the procedure were comparable among the groups. The number of patients in group III with the maximum Aldrete recovery score 5 min after the procedure was significantly lower than that in groups I and II. One patient in group II and one patient in group III suffered from nausea.

CONCLUSION

Similar pain-free conscious sedation conditions without significant changes in hemodynamic parameters were provided by all three protocols. However, target controlled infusion of remifentanil at 1.5 or 2 ng/mL proved superior at providing early recovery compared to 2.5 ng/mL.