Intraoperative patient-controlled analgesia: an alternative to physician administration during outpatient monitored anesthesia care

OUP accepted manuscript

STUDY QUESTION

What is the methodological validity and usefulness of randomized controlled trials (RCTs) on pain relief during oocyte retrieval for IVF and ICSI?

SUMMARY ANSWER

Key methodological characteristics such as randomization, allocation concealment, primary outcome measure and sample size calculation were inadequately reported in 33–43% of the included RCTs, and a broad heterogeneity is revealed in the studied outcome measures.

WHAT IS KNOWN ALREADY

A Cochrane review on conscious sedation and analgesia for women undergoing oocyte retrieval concluded that the overall quality of evidence was low or very low, mainly owing to poor reporting. This, and heterogeneity of studied outcome measures, limits generalizability and eligibility of results for meta-analysis.

STUDY DESIGN, SIZE, DURATION

For this review, a systematic search for RCTs on pain relief during oocyte retrieval was performed on 20 July 2020 in CENTRAL CRSO, MEDLINE, Embase, PsycINFO, CINAHL, ClinicalTrials.gov, WHO ICTRP, Web of Science, Portal Regional da BVS and Open Grey.

PARTICIPANTS/MATERIALS, SETTING, METHODS

RCTs with pain or patient satisfaction as an outcome were included and analysed on a set of methodological and clinical characteristics, to determine their validity and usefulness.

MAIN RESULTS AND THE ROLE OF CHANCE

Screening of 2531 articles led to an inclusion of 51 RCTs. Randomization was described inadequately in 33% of the RCTs. A low-risk method of allocation concealment was reported in 55% of the RCTs. Forty-nine percent of the RCTs reported blinding of participants, 33% of blinding personnel and 43% of blinding the outcome assessor. In 63% of the RCTs, the primary outcome was stated, but a sample size calculation was described in only 57%. Data were analysed according to the intention-to-treat principle in 73%. Treatment groups were not treated identically other than the intervention of interest in 10% of the RCTs. The primary outcome was intraoperative pain in 28%, and postoperative pain in 2%. The visual analogue scale (VAS) was the most used pain scale, in 69% of the RCTs in which pain was measured. Overall, nine other scales were used. Patient satisfaction was measured in 49% of the RCTs, for which 12 different methods were used. Occurrence of side-effects and complications were assessed in 77% and 49% of the RCTs: a definition for these was lacking in 13% and 20% of the RCTs, respectively. Pregnancy rate was reported in 55% of the RCTs and, of these, 75% did not adequately define pregnancy. To improve the quality of future research, we provide recommendations for the design of future trials. These include use of the VAS for pain measurement, use of validated questionnaires for measurement of patient satisfaction and the minimal clinically relevant difference to use for sample size calculations.

LIMITATIONS, REASONS FOR CAUTION

Consensus has not been reached on some methodological characteristics, for which we formulated recommendations. To prevent further heterogeneity in research on this topic, recommendations were formulated based on expert opinion, or on the most used method thus far. Future research may provide evidence to base new recommendations on.

WIDER IMPLICATIONS OF THE FINDINGS

Use of the recommendations given for design of trials on this topic can increase the generalizability of future research, increasing eligibility for meta-analyses and preventing wastefulness.

STUDY FUNDING/COMPETING INTEREST(S)

No specific funding was obtained for this study. S.B. reports being the editor-in-chief of Human Reproduction Open. For this manuscript, he was not involved with the handling process within Human Reproduction Open, or with the final decision. Furthermore, S.B. reports personal fees from Remuneration from Oxford University Press as editor-in-chief of Human Reproduction Open, personal fees from Editor and contributing author, Reproductive Medicine for the MRCOG, Cambridge University Press. The remaining authors declare no conflict of interest in relation to the work presented.

TRIAL REGISTRATION NUMBER

Not applicable.

Pain relief for women undergoing oocyte retrieval for assisted reproduction

BACKGROUND

Various methods of conscious sedation and analgesia (CSA) have been used during oocyte retrieval for assisted reproduction. The choice of agent has been influenced by the quality of sedation and analgesia and by concerns about possible detrimental effects on reproductive outcomes.

OBJECTIVES

To assess the effectiveness and safety of different methods of conscious sedation and analgesia for pain relief and pregnancy outcomes in women undergoing transvaginal oocyte retrieval.

SEARCH METHODS

We searched; the Cochrane Gynaecology and Fertility specialised register, CENTRAL, MEDLINE, Embase, PsycINFO and CINAHL, and trials registers in November 2017. We also checked references, and contacted study authors for additional studies.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) comparing different methods and administrative protocols for conscious sedation and analgesia during oocyte retrieval.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. Our primary outcomes were intraoperative and postoperative pain. Secondary outcomes included clinical pregnancy, patient satisfaction, analgesic side effects, and postoperative complications.

MAIN RESULTS

We included 24 RCTs (3160 women) in five comparisons. We report the main comparisons below. Evidence quality was generally low or very low, mainly owing to poor reporting and imprecision.1. CSA versus other active interventions.All evidence for this comparison was of very low quality.CSA versus CSA plus acupuncture or electroacupunctureData show more effective intraoperative pain relief on a 0 to 10 visual analogue scale (VAS) with CSA plus acupuncture (mean difference (MD) 1.00, 95% confidence interval (CI) 0.18 to 1.82, 62 women) or electroacupuncture (MD 3.00, 95% CI 2.23 to 3.77, 62 women).Data also show more effective postoperative pain relief (0 to 10 VAS) with CSA plus acupuncture (MD 0.60, 95% CI -0.10 to 1.30, 61 women) or electroacupuncture (MD 2.10, 95% CI 1.40 to 2.80, 61 women).Evidence was insufficient to show whether clinical pregnancy rates were different between CSA and CSA plus acupuncture (odds ratio (OR) 0.61, 95% CI 0.20 to 1.86, 61 women). CSA alone may be associated with fewer pregnancies than CSA plus electroacupuncture (OR 0.22, 95% CI 0.07 to 0.66, 61 women).Evidence was insufficient to show whether rates of vomiting were different between CSA and CSA plus acupuncture (OR 1.64, 95% CI 0.46 to 5.88, 62 women) or electroacupuncture (OR 1.09, 95% CI 0.33 to 3.58, 62 women).Trialists provided no usable data for other outcomes of interest.CSA versus general anaesthesia Postoperative pain relief was greater in the CSA group (0 to 3 Likert: mean difference (MD) 1.9, 95% CI 2.24 to 1.56, one RCT, 50 women).Evidence was insufficient to show whether groups differed in clinical pregnancy rates (OR 1.00, 95% CI 0.43 to 2.35, two RCTs, 108 women, I² = 0%).Evidence was insufficient to show whether groups differed in rates of vomiting (OR 0.46, 95% CI 0.08 to 2.75, one RCT, 50 women) or airway obstruction (OR 0.14, 95% CI 0.02 to 1.22, one RCT, 58 women). Fewer women needed mask ventilation in the CSA group (OR 0.05, 95% CI 0.01 to 0.20, one RCT, 58 women).Evidence was also insufficient to show whether groups differed in satisfaction rates (OR 0.66, 95% CI 0.11 to 4.04, two RCTs, 108 women, I² = 34%; very low-quality evidence).Trialists provided no usable data for outcomes of interest.2. CSA + paracervical block (PCB) versus other interventions.CSA + PCB versus electroacupuncture + PCB Intraoperative pain scores were lower in the CSA + PCB group (0 to 10 VAS: MD -0.66, 95% CI -0.93 to -0.39, 781 women, I² = 76%; low-quality evidence).Evidence was insufficient to show whether groups differed in clinical pregnancy rates (OR 0.96, 95% CI 0.72 to 1.29, 783 women, I² = 9%; low-quality evidence).Trialists provided no usable data for other outcomes of interest.CSA + PCB versus general anaesthesiaEvidence was insufficient to show whether groups differed in postoperative pain scores (0 to 10 VAS: MD 0.49, 95% CI -0.13 to 1.11, 50 women; very low-quality evidence).Evidence was insufficient to show whether groups differed in clinical pregnancy rates (OR 0.70, 95% CI 0.22 to 2.26, 51 women; very low-quality evidence).Trialists provided no usable data for other outcomes of interest.CSA + PCB versus spinal anaesthesiaPostoperative pain scores were higher in the CSA + PCB group (0 to 10 VAS: MD 1.02, 95% CI 0.48 to 1.56, 36 women; very low-quality evidence).Evidence was insufficient to show whether groups differed in clinical pregnancy rates (OR 0.93, 95% CI 0.24 to 3.65, 38 women; very low-quality evidence).Trialists provided no usable data for other outcomes of interest.CSA + PCB versus PCBEvidence was insufficient to show whether groups differed in clinical pregnancy rates (OR 0.93, 95% CI 0.44 to 1.96, 150 women; low-quality evidence) or satisfaction (OR 1.63, 95% CI 0.68 to 3.89, 150 women, low-quality evidence).Trialists provided no usable data for other outcomes of interest.CSA + PCB versus CSA only Evidence was insufficient to show whether groups differed in clinical pregnancy rates (OR 0.62, 95% CI 0.28 to 1.36, one RCT, 100 women; very low-quality evidence). Rates of postoperative nausea and vomiting were lower in the CS + PCB group (OR 0.42, 95% CI 0.18 to 0.97, two RCTs, 140 women, I² = 40%; very low-quality evidence).Trialists provided no usable data for other outcomes of interest.

AUTHORS' CONCLUSIONS

The evidence does not support one particular method or technique over another in providing effective conscious sedation and analgesia for pain relief during and after oocyte retrieval. Simultaneous use of sedation combined with analgesia such as the opiates, further enhanced by paracervical block or acupuncture techniques, resulted in better pain relief than occurred with one modality alone. Evidence was insufficient to show conclusively whether any of the interventions influenced pregnancy rates. All techniques reviewed were associated with a high degree of patient satisfaction. Women's preferences and resource availability for choice of pain relief merit consideration in practice.

Pain relief for women undergoing oocyte retrieval for assisted reproduction

BACKGROUND

Various methods of conscious sedation and analgesia have been used for pain relief during oocyte recovery in in vitro fertilisation (IVF) and intra-cytoplasmic sperm injection (ICSI) procedures. The choice of agent has also been influenced by the quality of sedation and analgesia as well as by concerns about possible detrimental effects on reproductive outcomes.

OBJECTIVES

To assess the effectiveness and safety of different methods of conscious sedation and analgesia on pain relief and pregnancy outcomes in women undergoing transvaginal oocyte retrieval.

SEARCH METHODS

We searched the Menstrual Disorders and Subfertility Group Specialised Register, Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library, MEDLINE, EMBASE, PsycINFO, CINAHL (from their inception to present); the National Research Register and Current Controlled Trials. We searched reference lists of included studies for relevant studies and contacted authors for information on unpublished and ongoing trials. There was no language restriction. The search was updated in July 2012.

SELECTION CRITERIA

Only randomised controlled trials comparing different methods of conscious sedation and analgesia for pain relief during oocyte recovery were included.

DATA COLLECTION AND ANALYSIS

Quality assessment and data extraction were performed independently by two review authors. Interventions were classified and analysed under broad categories or strategies of sedation and pain relief to compare different methods and administrative protocols of conscious sedation and analgesia. Outcomes were extracted and the data were pooled when appropriate.

MAIN RESULTS

With this update, nine new studies were identified resulting in a total of 21 trials including 2974 women undergoing oocyte retrieval. These trials compared five different categories of conscious sedation and analgesia: 1) conscious sedation and analgesia versus placebo; 2) conscious sedation and analgesia versus other active interventions such as general and acupuncture anaesthesia; 3) conscious sedation and analgesia plus paracervical block versus other active interventions such as general, spinal and acupuncture anaesthesia; 4) patient-controlled conscious sedation and analgesia versus physician-administered conscious sedation and analgesia; and 5) conscious sedation and analgesia with different agents or dosage. Evidence was generally of low quality, mainly due to poor reporting of methods, small sample sizes and inconsistency between the trials.Conflicting results were shown for women's experience of pain. Compared to conscious sedation alone, more effective pain relief was reported when conscious sedation was combined with electro-acupuncture: intra-operative pain mean difference (MD) on 1 to 10 visual analogue scale (VAS) of 3.00 (95% CI 2.23 to 3.77); post-operative pain MD in VAS units of 2.10 (95% CI 1.40 to 2.80; N = 61, one trial, low quality evidence); or paracervical block (MD not calculable).The pooled data of four trials showed a significantly lower intra-operative pain score with conscious sedation plus paracervical block than with electro-acupuncture plus paracervical block (MD on 10-point VAS of -0.66; 95% CI -0.93 to -0.39; N = 781, 4 trials, low quality evidence) with significant statistical heterogeneity (I(2) = 76%). Patient-controlled sedation and analgesia was associated with more intra-operative pain than physician-administered sedation and analgesia (MD on 10-point VAS of 0.60; 95% CI 0.16 to 1.03; N = 379, 4 trials, low quality evidence) with high statistical heterogeneity (I(2) = 83%). Post-operative pain was reported in only nine studies. As different types and dosages of sedative and analgesic agents, as well as administrative protocols and assessment tools, were used in these trials the data should be interpreted with caution.There was no evidence of a significant difference in pregnancy rate in the 12 studies which assessed this outcome, and pooled data of four trials comparing electro-acupuncture combined with paracervical block with conscious sedation and analgesia plus paracervical block showed an odds ratio (OR) of 0.96 (95% CI 0.72 to 1.29; N = 783, 4 trials) for pregnancy. High levels of women's satisfaction were reported for all modalities of conscious sedation and analgesia as assessed in 12 studies. Meta-analysis of all the studies was not attempted due to considerable heterogeneity.For the rest of the trials a descriptive summary of the outcomes was presented.

AUTHORS' CONCLUSIONS

The evidence from this review of 21 randomised controlled trials did not support one particular method or technique over another in providing effective conscious sedation and analgesia for pain relief during and after oocyte recovery. The simultaneous use of more than one method of sedation and pain relief resulted in better pain relief than one modality alone. The various approaches and techniques reviewed appeared to be acceptable and were associated with a high degree of satisfaction in women. As women vary in their experience of pain and in coping strategies, the optimal method may be individualised depending on the preferences of both the women and the clinicians and resource availability.

The patients' perspective on fertility care: a systematic review

BACKGROUND

Patient-centered reproductive medicine (PCRM) is important for quality of care, and this is increasingly being recognized. However, its scientific basis is unclear. The main research questions addressed in this review are: 'How has the patients' perspective on fertility care been examined (method and quality)?' and 'What is the perspective of patients in developed countries on fertility care?'.

METHODS

A systematic search of electronic databases was conducted and inclusion criteria with respect to eligibility and quality were applied. The methodology of the studies was critically appraised; the findings of the studies were synthesized and organized according to: patients' value clarification and assessment of service quality and dimensions of patient-centeredness. Additionally data on patient preferences and determinants of patients' perspective on care were collected.

RESULTS

In 51 selected studies, patients' perspective on fertility care was examined with (few or many item) questionnaires and/or qualitative interviews. Significant methodological problems were observed. Fertility patients attached importance to seven out of eight dimensions of patient-centeredness (Picker institute) and two new dimensions 'fertility clinic staff' and 'skills' were developed. Overall, fertility patients want to be treated like human beings with a need for: medical skills, respect, coordination, accessibility, information, comfort, support, partner involvement and a good attitude of and relationship with fertility clinic staff. Patients' preferences between procedures and demographic, medical and psychological determinants of their perspective were defined.

CONCLUSIONS

Fertility patients have 'human needs' besides their need for medical care. Evidence on PCRM is available but significant methodological limitations call for the development and validation of a European questionnaire.

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

BACKGROUND

Various methods of sedation and analgesia have been used for pain relief during oocyte recovery during IVF.

OBJECTIVE

To compare conscious sedation and analgesia with alternative methods for pain relief and pregnancy outcomes.

METHODS

We searched the Specialised Register of the Menstrual Disorders and Subfertility Group, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, CINAHL, the National Research Register and Current Controlled Trials up to February 2004.

RESULTS

Twelve trials were included. Owing to considerable heterogeneity, regarding types and dosages of sedation or analgesia used, and tools used to assess pain, a meta-analysis was attempted only in trials where appropriate data were available. Clinical pregnancy rates per woman in individual trials were comparable. Data on pain showed conflicting results.

CONCLUSION

No single method or delivery system appeared superior for pregnancy rates and pain relief. Future studies need to be consistent in the choice of tools used to measure pain and the timing of such evaluations.

Conscious sedation and analgesia for oocyte retrieval during in vitro fertilisation procedures

BACKGROUND

Various methods of sedation and analgesia have been used for pain relief during oocyte recovery in IVF/ICSI procedures. The choice of agents has also been influenced by quality of analgesia as well as by concern about possible detrimental effects on reproductive outcome.

OBJECTIVES

To assess the efficacy of conscious sedation and analgesia versus alternative methods on pregnancy outcomes and pain relief in patients undergoing transvaginal oocyte retrieval.

SEARCH STRATEGY

We searched the Specialised Register of the Menstrual Disorders and Subfertility Group, The Central Register of Controlled Trials (CENTRAL) , MEDLINE (1966 to present), EMBASE (1980 to present), CINAHL (1982 to present), the National Research Register, and Current Controlled Trials. There was no language restriction. All references in the identified trials and background papers were checked and authors contacted to identify relevant published and unpublished data.

SELECTION CRITERIA

Only randomised controlled trials comparing conscious sedation and analgesia versus alternative methods for pain relief during oocyte recovery were included.

DATA COLLECTION AND ANALYSIS

Two reviewers independently scanned abstracts of the reports identified by electronic searching to identify relevant papers, extracted data and assessed trial quality. Interventions were classified and analysed under broad categories/strategies of pain relief comparing conscious sedation/analgesia with alternative methods and administration protocols.

MAIN RESULTS

Our search strategy identified 390 potentially eligible reports and 12 papers met our inclusion criteria. There were no significant differences in clinical pregnancy rates per woman and patient satisfaction between the methods compared. Women's perception of pain showed conflicting results. Due to considerable heterogeneity, in terms of types and dosages of sedation or analgesia used, and tools used to assess the principal outcomes of pain and satisfaction, a meta-analysis of all the studies was not attempted. Of the three trials which compared the effect of conventional medical analgesia plus paracervical block versus electro-acupuncture plus paracervical block, there was no significant difference in clinical pregnancy rates per woman in the two groups (OR 1.01; 95% CI 0.73 to 1.4). For intra-operative pain score as measured by visual analogue scale (VAS), there was a significant difference (WMD -4.95; 95% CI -7.84 to -2.07), favouring conventional medical analgesia plus paracervical block . There was also a significant difference in intra-operative pain by VAS between patient-controlled sedation and physician-administered sedation (WMD 5.98; 95% CI 1.63 to 10.33), favouring physician -administered sedation. However, as different types and dosages of sedative and analgesic agents were used in these trials, these data should be interpreted with caution. For the rest of the trials, a descriptive summary of the outcomes was presented.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine the effect of different methods of pain relief when compared with conscious sedation and analgesia used during oocyte recovery. In this review, no one particular pain relief method or delivery system appeared to be better than the other. In future, greater consensus is needed to determine both the tools used to evaluate pain and the timing of pain evaluation during and after the procedure. Pain assessment using both subjective and objective measures may merit consideration. In addition, future trials should include intra- and post-operative adverse respiratory and cardiovascular events as outcomes.

A comparison of patient-controlled analgesia fentanyl and alfentanil for labour analgesia

PURPOSE

To determine the analgesic efficacy of equipotent doses of PCA (patient-controlled analgesia) fentanyl and PCA alfentanil for labour pain.

METHODS

Twenty three, ASA I - II parturients between 32-42 wk gestational age in whom epidural analgesia was contraindicated were randomized to receive PCA fentanyl (Group F)or alfentanil (Group A). Plain numbered vials contained 21 ml fentanyl 50 microg x ml(-1) or alfentanil 500 microg x ml(-1). A one millilitre loading dose was administered. The PCA solution was prepared by diluting 10 ml study drug with 40 ml saline and the PCA pump was programmed to deliver a dose of 2 ml, delay of five minutes and a basal rate of 2 ml x hr(-1). Maternal measurements obtained were hourly drug dose, total dose, Visual Analog Pain Score (VAPS) q 30 min, sedation score q 1 hr and side effects. Neonates were assessed by 1,5, and 10-min Apgar scores, umbilical venous and arterial blood gases and neurobehavioural scores at four and 24 hr.

RESULTS

Mean VAPS from 7 - 10 cm cervical dilatation were higher in Group A than in Group F (85.7+/-13.9 vs. 64.6+/-12.1; P<0.01) There were no inter-group differences in VAPS from 1-3 cm, or from 4-6 cm dilatation, in maternal sedation scores or side effects, or in neonatal outcomes.

CONCLUSION

In the doses prescribed in this study, PCA fentanyl was found to provide more effective analgesia in late first stage labour than PCA alfentanil.

Use of alfentanil for in vitro fertilization oocyte retrieval

STUDY OBJECTIVES

To determine alfentanil levels with a specific radioimmunoassay in serum and ovarian follicular fluid.

DESIGN

Observational study.

SETTING

University hospital.

PATIENTS

14 ASA status I women undergoing oocyte retrieval for in vitro fertilization.

INTERVENTIONS

General anesthesia was induced with alfentanil 15 micrograms/kg and midazolam 2 mg and maintained with alfentanil 0.5 mg, 60% nitrous oxide (N2O) in oxygen (O2) and midazolam up to a total of 4 mg. Oocyte retrieval was performed using a transvaginal ultrasound guided technique, 34 to 36 hours after human chorionic gonadotrophin administration.

MEASUREMENTS AND MAIN RESULTS

Mean procedure time for oocyte retrieval was 18 +/- 2.4 (SEM) minutes. All patients were fully awake within 5 minutes and all patients except one were able to move from the operating table to the stretcher with minimal help. Mean total protein concentration in the follicular fluid was 3.8 +/- 0.4 mg%. Maximal serum alfentanil concentrations (Cmax) were attained 5 minutes after start of the procedure (tmax) and were 92 +/- 20 ng/ml. In contrast, alfentanil concentrations in the follicular fluid increased constantly throughout the procedure up to 8.9 +/- 0.8 ng/ml at 15 minutes. Clinical pregnancy rate was 3 of 14 patients.

CONCLUSION

It is evident that during the oocyte retrieval procedure, the alfentanil concentrations in the follicular fluid are about ten-fold smaller than the serum alfentanil concentrations at the same time points. Similar pharmacokinetics have been shown when propofol was used as anesthetic. The low accumulation of alfentanil in the follicular fluid increases the attractiveness of alfentanil for anesthesia during oocyte retrieval for in vitro fertilization.

Application of cost-utility and quality-adjusted life years analyses to monitored anesthesia care for sedation only

STUDY OBJECTIVE

To determine how much society should spend to decrease anxiety lasting for the duration of a surgical case.

DESIGN

Indications for monitored-anesthesia care (MAC) include: (1) management of an unstable patient, (2) possible induction of general anesthesia, (3) need for the patient to be unconscious for part of the case, and (4) provision of sedation and/or analgesia. The first three indications facilitate quality surgical care. However, MAC solely to decrease anxiety has been criticized on economic grounds. Although MAC for these cases may improve the patient's experience during surgery, it does not facilitate safer surgery. I limited my theoretical analysis to (1) MAC for sedation only and (2) procedures that have an equal outcome with or without an anesthesiologist. Cost-utility analyses compare costs and benefits of technologies by using a common measure of health outcomes. The quality adjusted life year (QALY) gives the expected life years gained from a procedure, with each year weighted to reflect quality of life in that year. Quality of life generally ranges from zero (dead) to one (healthy without distress). Technologies costing more than $75,000 per QALY are usually considered too expensive to justify. I used a deliberately absurd, one unit change in quality of life to calculate the maximum hourly cost of MAC, which lets the cost per QALY be less than $75,000.

MEASUREMENTS AND MAIN RESULTS

Hourly cost must be less than $8.56 per hour. Current Medicare reimbursement corresponds to $876,000 per QALY.

CONCLUSION

MAC for sedation only is a very expensive technology compared with other medical interventions.

Comparison of propofol administration techniques for sedation during monitored anesthesia care

Sixty-three outpatients undergoing breast biopsy procedures with local anesthesia were randomly assigned to receive propofol by intermittent bolus injections (n = 21), a conventional syringe infusion pump (n = 21), or a target-controlled infusion (TCI) device (n = 21) for intraoperative sedation. In the first two groups, an initial intravenous (IV) bolus of propofol (0.3 mg/kg) was administered and an attempt was made to maintain the sedation level at an Observer's Assessment of Alertness/Sedation (OAA/S) score of 3 or 4 with either intermittent bolus injections of propofol (10 mg) or a variable-rate infusion (25-100 micrograms.kg-1.min-1). In the TCI group, the initial target concentration of propofol was set at 2 micrograms/mL and the target concentration was adjusted between 1 and 4 micrograms/mL in an attempt to maintain an OAA/S score of 3 or 4. Recovery was assessed using clinical criteria, visual analog scales (VAS), and the digit-symbol substitution test (DSST). The overall quality of sedation, operating conditions, and clinical recovery profiles were similar in all three treatment groups. The anesthesiologist had to intervene more frequently in the intermittent bolus injection group than in the two infusion groups. We conclude that the use of an infusion technique may allow the anesthesiologist more time for monitoring the patient by decreasing the number of interventions necessary to administer supplemental doses of the sedative medication during the operation. However, the cost of the IV drug delivery system may become an increasingly important factor in the future.

Intra-operative patient-controlled sedation and patient attitude to control. A crossover comparison of patient preference for patient-controlled propofol and propofol by continuous infusion

Intra-operative patient controlled sedation with propofol (bolus dose 18 mg over 5.4 s; lockout period 1 min) has been compared to continuous propofol infusion (3.6 mg.kg-1.h-1) in a randomised crossover study of 38 ASA 1 or 2 day surgery patients undergoing two-stage bilateral extraction of third molar teeth under local anaesthesia (76 procedures). Mean (SD) propofol used (mg.kg-1) was less with patient-controlled sedation (2.39 (1.28) than with the infusion (2.58 (0.84)) but the difference was not statistically significant. There were only minor differences between the methods in postoperative recovery of cognitive function and no differences for patient cooperation and surgeon's satisfaction with sedation. Patient-controlled sedation was preferred by 19 patients, continuous infusion by 10, with nine indifferent. Preferences, expressed as mild, moderate or strong, were significantly stronger for patient-controlled sedation (p < 0.05). Sedation was no deeper than eyelid closure with response to command in all 76 procedures. This level was reached in all 38 infusion cases but in only 26 cases with patient-controlled sedation, where 12 patients remained less sedated (p < 0.01). Patient-controlled sedation with propofol provided safe sedation and was strongly preferred over the infusion by a large proportion of patients.

Patient-controlled drug administration during local anesthesia: a comparison of midazolam, propofol, and alfentanil

STUDY OBJECTIVE

To evaluate the perioperative effects of alfentanil, midazolam, and propofol when administered using a patient-controlled analgesia (PCA) device during local anesthesia.

DESIGN

Randomized, single-blind comparative study.

SETTING

Outpatient surgery center at a university teaching hospital.

PATIENTS

Ninety outpatients undergoing minor elective surgical procedures with local anesthetic infiltration were assigned to one of three treatment groups.

INTERVENTIONS

After premedication with midazolam 1 mg intravenously (IV) and fentanyl 50 micrograms IV, patients were allowed to self-administer 2 ml bolus doses of either alfentanil 250 micrograms/ml, midazolam 0.4 mg/ml, or propofol 10 mg/ml at minimal intervals of 3 minutes to supplement a basal infusion rate of 5 ml/hr.

MEASUREMENTS AND MAIN RESULTS

The total intraoperative dosages of alfentanil, midazolam, and propofol were 2.7 +/- 1.1 mg, 4.7 +/- 2.7 mg, and 114 +/- 42 mg, respectively, for procedures lasting 48 +/- 28 minutes to 51 +/- 19 minutes (means +/- SD). Propofol produced more pain on injection (39% vs. 4% and 6% in the alfentanil and midazolam groups, respectively). Episodes of arterial oxygen saturation less than 90% were more frequent with alfentanil (28%) than with midazolam (3%) or propofol (13%). Using the visual analog scale, patients reported comparable levels of discomfort, anxiety, and sedation during the operation in all three treatment groups. Postoperative picture recall was significantly decreased with midazolam versus alfentanil and propofol. Finally, postoperative nausea was reported more frequently in the alfentanil group (29%) than in the midazolam (10%) or propofol (18%) groups, contributing to a significant prolongation of the discharge time in the alfentanil-treated patients.

CONCLUSIONS

When self-administered as adjuvants during local anesthesia using a PCA delivery system, alfentanil, midazolam, and propofol were equally acceptable to patients. However, propofol and midazolam were associated with fewer perioperative complications than was alfentanil.