Use of Alfentanil and Propofol for Outpatient Monitored Anesthesia Care

Effect of epidural dexmedetomidine in single-dose combined with ropivacaine for cesarean section

BACKGROUND

Dexmedetomidine has arousal sedation and analgesic effects. We hypothesize that epidural dexmedetomidine in single-dose combined with ropivacaine improves the experience of parturient undergoing cesarean section under epidural anesthesia. This study is to investigate the effect of 0.5 µg/kg epidural dexmedetomidine combined with epidural anesthesia (EA) in parturients undergoing cesarean section.

METHODS

A total of 92 parturients were randomly divided into Group R (receiveing epidural ropivacaine alone) Group RD (receiveing epidural ropivacaine with 0.5 µg/kg dexmedetomidine). The primary outcome and second outcome will be intraoperative NRS pain scores and Ramsay Sedation Scale.

RESULTS

All 92 parturients were included in the analysis. The NRS were significantly lower in Group RD compared to Group R at all observation timepoint (P > 0.05). Higher Ramsay Sedation Scale was found in Group RD compared to Group R (P < 0.001). No parturient has experienced sedation score of 4 and above. No significant difference regarding the incidence of hypotension, bradycardia and nausea or vomiting, Apgar scores and the overall satisfaction with anesthesia was found between Group R and Group RD (P > 0.05).

CONCLUSION

Epidural dexmedetomidine of 0.5 µg/kg added slightly extra analgesic effect to ropivacaine in EA for cesarean section. The sedation of 0.5 µg/kg epidural dexmedetomidine did not cause mother-baby bonding deficit. Satisfaction with anesthesia wasn't significantly improved by epidural dexmedetomidine of 0.5 µg/kg. No additional side effect allows larger dose of epidural dexmedetomidine attempt.

TRIAL REGISTRATION

This study was registered at www.chictr.org.cn (ChiCTR2000038853).

Ciprofol as compared to propofol for sedation and general anesthesia: a systematic review of randomized controlled trials

BACKGROUND

Propofol is the most commonly used hypnotic agent used during sedation and general anesthesia (GA) practice, offering faster recovery compared to benzodiazepines. However, cardiovascular impact of propofol and pain at injection are commonly encountered side effects. Ciprofol is a novel disubstituted phenol derivative, and there is growing evidence regarding its clinical use.

METHODS

We conducted a systematic literature search (updated on 23 July 2023) to evaluate safety and efficacy of ciprofol in comparison to propofol in patients undergoing procedures under sedation or GA. We focused on randomized controlled trials (RCTs) only, extrapolating data on onset and offset, and on the side effects and the pain at injection.

RESULTS

The search revealed 14 RCTs, all conducted in China. Eight RCTs studied patients undergoing sedation, and six focused on GA. Bolus of ciprofol for sedation or induction of GA varied from 0.2 to 0.5 mg/kg. In four studies using ciprofol for maintenance of GA, it was 0.8-2.4 mg/kg/h. Ciprofol pharmacokinetics seemed characterized by slower onset and offset as compared to propofol. Pain during injection was less frequent in the ciprofol group in all the 13 studies reporting it. Eight studies reported "adverse events" as a pooled outcome, and in five cases, the incidence was higher in the propofol group, not different in the remaining ones. Occurrence of hypotension was the most commonly investigated side effects, and it seemed less frequent with ciprofol.

CONCLUSION

Ciprofol for sedation or GA may be safer than propofol, though its pharmacokinetics may be less advantageous.

Efficacy and Safety of Ciprofol for Sedation/Anesthesia in Patients Undergoing Hysteroscopy: A Randomized, Parallel-Group, Controlled Trial

Objective

To compare the efficacy and safety of ciprofol and propofol for sedation during hysteroscopy.

Methods

A total of 149 patients undergoing hysteroscopy were randomly assigned to a ciprofol (Group C) or propofol group (Group P). All cases received intravenous sufentanil 0.1 µg/kg for analgesic preconditioning. Group C received an induction dose of ciprofol 0.4 mg/kg and a maintenance dosage of 0.6-1.2 mg/kg/h to maintain BIS value between 40-60. In Group P, propofol was started at 2.0 mg/kg and then maintained at 3.0-6.0 mg/kg/h. The primary outcome was the successful rate of hysteroscopy. Secondary outcomes included the change of hemodynamic, respiratory adverse events, injection pain, body movement, recovery time, anesthetist's satisfaction, time of disappearance of the eyelash reflex and the incidence of nausea and vomiting.

Results

The success rate of hysteroscopy in each group was 100%. After drug administration, the incidence of hypotension in Group C was much lower than that in Group P (P< 0.05). The incidence of respiratory adverse events in Group C (4.0%) was much lower than that in Group P (31.1%) (P< 0.05). The incidence of injection pain and body movement in Group C was significantly lower than that in Group P (P< 0.05). The mean eyelash reflex disappearance time was less than 3 minutes in both groups. There was no statistically significant difference between the two groups in awakening times, anesthetist's satisfaction and the incidence of nausea and vomiting. No serious adverse events occurred in any patients.

Conclusion

Ciprofol proved to be a safer alternative to propofol for anesthesia during hysteroscopy. In comparison to propofol, ciprofol does not cause injection pain, exerts less impact on hemodynamics, and results in less respiratory depression.

Direct visualization of general anesthetic propofol on neurons by stimulated Raman scattering microscopy

The consensus for the precise mechanism of action of general anesthetics is through allosteric interactions with GABA receptors in neurons. However, it has been speculated that these anesthetics may also interact with the plasma membrane on some level. Owing to the small size of anesthetics, direct visualization of these interactions is difficult to achieve. We demonstrate the ability to directly visualize a deuterated analog of propofol in living cells using stimulated Raman scattering (SRS) microscopy. Our findings support the theory that propofol is highly concentrated and interacts primarily through non-specific binding to the plasma membrane of neurons. Additionally, we show that SRS microscopy can be used to monitor the dynamics of propofol binding using real-time, live-cell imaging. The strategy used to visualize propofol can be applied to other small molecule drugs that have been previously invisible to traditional imaging techniques

•

Multi-modal SRS developed for real-time biological imaging of small molecule substances

•

Propofol primarily concentrates at the cell membrane of neurons

•

Anesthesia dynamics can be monitored in real-time with SRS

Dexmedetomidine-remifentanil vs propofol-remifentanil for monitored anesthesia care during hysteroscopy: Randomized, single-blind, controlled trial

BACKGROUND

Although dexmedetomidine has been used as either the anesthetic agent for light sedation or as an adjunct to other sedatives, no study has investigated the usefulness of dexmedetomidine as the main sedative agent for invasive and painful procedures. The purpose of this study was to compare the safety of dexmedetomidine-remifentanil and propofol-remifentanil during monitored anesthesia care (MAC) for hysteroscopy.

METHODS

Female patients undergoing hysteroscopy were randomly assigned to either the dexmedetomidine (group D) or the propofol group (group P). The study drug (0.6 ml/kg; dexmedetomidine 2 μg/ml or propofol 4 mg/ml) was loaded for 10 minutes followed by 0.1 to 0.5 ml/kg/hour to maintain a bispectral index of 60 to 80 during the procedure. In both groups, remifentanil was infused using a target-controlled-infusion system with a target concentration of 2 ng/ml and titrated during the procedure. The incidence rates of intraoperative respiratory depression in both groups were compared. Postoperative pain and patients satisfaction were also compared.

RESULTS

A total of 69 female patients were included in this study. Dexmedetomidine significantly decrease the incidence of respiratory depression compared with propofol (15/34 [44.1%] vs 5/35 [14.3%], P = .006, group P and D, respectively). Postoperative pain and patients satisfaction score did not differ between the groups.

CONCLUSION

The combination of dexmedetomidine-remifentanil can reduce the incidence of respiratory depression without increasing hemodynamic complications compared with propofol-remifentanil for MAC during hysteroscopy.

A Comparison of Retrobulbar Block, Sub-Tenon Block, and Topical Anesthesia during Cataract Surgery

Purpose

This randomized, double-blinded, prospective study was performed to compare the intraoperative hemodynamic variables and the patient-reported outcomes, such as intra- and postoperative analgesia and patient satisfaction, of retrobulbar block, sub-Tenon block, and topical anesthesia during cataract surgery under monitored anesthesia care.

Methods

Eighty-one patients, ASA physical status I–III, undergoing elective cataract surgery under monitored anesthesia care, aged between 43 and 78 years, were randomly assigned to three groups: retrobulbar block (group R), sub-Tenon block (group S), or topical anesthesia (group T). Three minutes after the start of monitored anesthesia care with lidocaine-propofol-remifentanil mixture, an ophthalmologist performed regional anesthesia. Intraoperative hemodynamics, pain score, and patients' satisfaction with the anesthetic experiences were recorded by a study-blinded anesthesiologist.

Results

Mean arterial pressure and heart rate in group R were significantly higher than those in groups S and T during and just after the regional block (p<0.05). Group R required smaller dosage of patient controlled sedation and fewer supplemental bolus doses than groups S and T (p<0.05). On the other hand, group S showed the highest satisfaction scores among the three groups (p<0.05).

Conclusions

Sub-Tenon block seems to be better than retrobulbar block and topical anesthesia in patient satisfaction though adequate analgesia was achieved after retrobulbar block during cataract surgery under monitored anesthesia care.

[Effect of intraoperative esmolol infusion on anesthetic, analgesic requirements and postoperative nausea-vomitting in a group of laparoscopic cholecystectomy patients]

PURPOSE

Postoperative pain and nausea/vomitting (PNV) are common in laparoscopic cholecystectomy patients. Sympatholytic agents might decrease requirements for intravenous or inhalation anesthetics and opioids. In this study we aimed to analyze effects of esmolol on intraoperative anesthetic-postoperative analgesic requirements, postoperative pain and PNV.

METHODS

Sixty patients have been included. Propofol, remifentanil and vecuronium were used for induction. Study groups were as follows; I - Esmolol infusion was added to maintenance anesthetics (propofol and remifentanil), II - Only propofol and remifentanil was used during maintenance, III - Esmolol infusion was added to maintenance anesthetics (desflurane and remifentanil), IV - Only desflurane and remifentanil was used during maintenance. They have been followed up for 24h for PNV and analgesic requirements. Visual analog scale (VAS) scores for pain was also been evaluated.

RESULTS

VAS scores were significantly lowest in group I (p=0.001-0.028). PNV incidence was significantly lowest in group I (p=0.026). PNV incidence was also lower in group III compared to group IV (p=0.032). Analgesic requirements were significantly lower in group I and was lower in group III compared to group IV (p=0.005). Heart rates were significantly lower in esmolol groups (group I and III) compared to their controls (p=0.001) however blood pressures were similar in all groups (p=0.594). Comparison of esmolol groups with controls revealed that there is a significant decrease in anesthetic and opioid requirements (p=0.024-0.03).

CONCLUSION

Using esmolol during anesthetic maintenance significantly decreases anesthetic-analgesic requirements, postoperative pain and PNV.

Sedation-analgesia in elective colonoscopy: propofol-fentanyl versus propofol-alfentanil

BACKGROUND AND OBJECTIVES

Sedation-analgesia is recommended for comfortable colonoscopy procedures, which are invasive and can be painful. This study aimed to compare the combinations of propofol-alfentanil and propofol-fentanyl for sedation-analgesia in elective colonoscopy patients.

METHODS

This prospective and randomized study was planned in ASA I-II groups and included 80 patients between the ages of 18 and 65 years. Sedation-analgesia induction was performed as 1 μg.kg-1 fentanyl, 1 mg.kg-1 propofol in the propofol-fentanyl group (Group PF) and 10 μg.kg-1 alfentanil, 1 mg.kg-1 propofol in the propofol-alfentanil group (Group PA). Patients’ scores were limited to 3-4 values on the Ramsey Sedation Scale (RSS) by 0.5 mg.kg-1 bolus additional doses of propofol in sedation-analgesia maintenance. We recorded demographical data, heart rate, mean arterial pressure (MAP), oxygen saturation of hemoglobin (SpO2), RSS value, colonoscopy time, total dose of propofol, complications, recovery time, and discharge time, as well as colonoscopist and patient satisfaction scores.

RESULTS

MAP at the 15th minute in Group PA was signifi cantly higher than in Group PF (p = 0.037). Group PA’s beginning mean heart rate was higher than the mean heart rate at subsequent readings (p = 0.012, p = 0.002). The mean total propofol dose of Group PA was signifi cantly higher than the total dose of Group PF (p = 0.028). The mean recovery time of Group PA was signifi cantly longer than that of Group PF (p = 0.032).

CONCLUSION

Fentanyl provides better operative conditions and reduces the need for additional propofol doses. These advantages cause a shorter recovery time. Therefore, propofol-fentanyl is superior to the propofol-alfentanil for sedation-analgesia in colonoscopy.

Sedation-analgesia in elective colonoscopy: propofol-fentanyl versus propofol-alfentanil

BACKGROUND AND OBJECTIVES

Sedation-analgesia is recommended for comfortable colonoscopy procedures, which are invasive and can be painful. This study aimed to compare the combinations of propofol-alfentanil and propofol-fentanyl for sedation-analgesia in elective colonoscopy patients.

METHODS

This prospective and randomized study was planned in ASA I-II groups and included 80 patients between the ages of 18 and 65 years. Sedation-analgesia induction was performed as 1 μg.kg(-1) fentanyl, 1mg.kg(-1) propofol in the propofol-fentanyl group (Group PF) and 10 μg.kg(-1) alfentanil, 1mg.kg(-1) propofol in the propofol-alfentanil group (Group PA). Patients' scores were limited to 3-4 values on the Ramsey Sedation Scale (RSS) by 0.5mg.kg(-1) bolus additional doses of propofol in sedation-analgesia maintenance. We recorded demographical data, heart rate, mean arterial pressure (MAP), oxygen saturation of hemoglobin (SpO2), RSS value, colonoscopy time, total dose of propofol, complications, recovery time, and discharge time, as well as colonoscopist and patient satisfaction scores.

RESULTS

MAP at the 15(th) minute in Group PA was significantly higher than in Group PF (p = 0.037). Group PA's beginning mean heart rate was higher than the mean heart rate at subsequent readings (p = 0.012, p = 0.002). The mean total propofol dose of Group PA was significantly higher than the total dose of Group PF (p = 0.028). The mean recovery time of Group PA was significantly longer than that of Group PF (p = 0.032).

CONCLUSION

Fentanyl provides better operative conditions and reduces the need for additional propofol doses. These advantages cause a shorter recovery time. Therefore, propofol-fentanyl is superior to the propofol-alfentanil for sedation-analgesia in colonoscopy.

The comparison of sedation quality, side effect and recovery profiles on different dosage of remifentanil patient-controlled sedation during breast biopsy surgery

BACKGROUND

The patient-controlled sedation (PCS) allows for rapid individualized titration of sedative drugs. Propofol has been the most widely used IV adjuvant, during the monitored anesthesia care (MAC). This study was designed to compare the sedation quality, side effect and recovery of the propofol alone, and propofol-remifentanil combination, using PCS for breast biopsy.

METHODS

Seventy five outpatients, undergoing breast biopsy procedures with local anesthesia, were randomly assigned to receive propofol alone (group P), propofol-25 ug/ml of remifentanil (group PR25), and propofol-50 ug/ml of remifentanil (group PR50), using PCS. Pain visual analogue scores (VAS) and digit symbol substitution test (DSST), Vital signs, bi-spectral index (BIS) and observer assessment of alertness and sedation (OAA/S) score were recorded.

RESULTS

Apply/Demand ratio in the group PR50 had a significant increase over the other groups (P < 0.05). The incidence of excessive sedation and dizziness were significantly more frequent in the group PR50 (P < 0.05). BIS and OAA/S score significantly decreased in the group PR25, PR50 at 15 min after the operation, the end of surgery (P < 0.05). At 5 min after the start of PCS, patients in the group PR25 and PR50 gave significantly less correct responses on the DSST than that of the group P (P < 0.05).

CONCLUSIONS

Compared with the propofol alone, intermittent bolus injection of propofol-remifentanil mixture could be used, appropriately, for the sedation and analgesia during MAC. The group PR25 in a low dose of remifentanil has more advantages in terms of sedation and satisfaction because of the group PR50's side effects.

Dexmedetomidine is effective for monitored anesthesia care in outpatients undergoing cataract surgery

BACKGROUND

Dexmedetomidine has a sedative analgesic property without respiratory depression. This study evaluated the efficacy of dexmedetomidine as an appropriate sedative drug for monitored anesthesia care (MAC) in outpatients undergoing cataract surgery on both eyes compared with combination of propofol and alfentanil.

METHODS

Thirty-one eligible patients were randomly divided into two groups on the first operation day. Dexmedetomidine was administered in group D at 0.6 µg/kg/h, and propofol and alfentanil was infused concomitantly in group P at a rate of 2 mg/kg/h and 20 µg/kg/h, respectively. Sedation was titrated at Ramsay sedation score 3. Iowa satisfaction with anesthesia scale (ISAS) of the patients was evaluated postoperatively. Systolic blood pressure (SBP), heart rate (HR), respiration rate (RR), and peripheral oxygen saturation (SpO(2)) were recorded throughout the surgery. For the second operation, the group assignments were exchanged.

RESULTS

Postoperative ISAS was 50.3 (6.2) in group D and 42.7 (8.7) in group P, which was statistically significant (P < 0.001). SBP was significantly lower in group D compared with group P from the beginning of the operation. HR, RR, and SpO(2) were comparable between the two groups. There were 8 cases (25.8%) of hypertension in group P, and 1 case (3.2%) in group D (P < 0.05). In contrast, 1 case (3.2%) of hypotension and 1 case (3.2%) of bradycardia occurred in group D.

CONCLUSIONS

Compared with the combined use of propofol and alfentanil, dexmedetomidine could be used appropriately for MAC in cataract surgery with better satisfaction from the patients and a more stable cardiovascular state.

Evidence-based review of enhancing postoperative recovery after breast surgery

BACKGROUND

The introduction of enhanced recovery after surgery (ERAS) protocols has revolutionized preoperative and postoperative care. To date, however, the principles of enhanced recovery have not been applied specifically to patients undergoing breast surgery.

METHODS

Based on the core features of ERAS, individual aspects of postoperative care in breast surgery were defined. A comprehensive search of MEDLINE, PubMed, Embase and the Cochrane Library database was performed from 1980 to 2010 to determine the best evidence for perioperative care in oncological breast surgery. A graded recommendation based on the best level of evidence was then proposed for each feature of ERAS.

RESULTS

Twelve core features of enhanced recovery after breast surgery were identified. Use of the thoracic block, from both analgesic and anaesthetic viewpoints, is well supported by evidence and should be encouraged. Trials specific to breast surgery regarding aspects such as perioperative fasting, preanaesthetic medication, prevention of hypothermia and postdischarge support are scarce, and evidence was extrapolated from non-breast trials. Trials on postoperative analgesia and prevention of postoperative nausea and vomiting in breast surgery are generally of small numbers. In addition, there is heterogeneity between studies.

CONCLUSION

This review suggests that the principles of enhanced recovery can be adopted in breast surgery. A 12-point protocol is proposed for prospective evaluation.

[Anxiety: an independent factor of axillary brachial plexus block failure?]

OBJECTIVE

To evaluate the impact of the anxiety level using Spielberger test on axillary block success.

STUDY DESIGN

Prospective double-blind study.

PATIENTS AND METHODS

An axillary brachial plexus block was performed with a nerve stimulator for all patients undergoing elective or emergency upper limb surgery. Spielberger test result was blinded for both patient and anaesthesiologist performing the block. Time to perform the block (minutes) was measured. Anxiety and pain scores were assessed, using a numeric scale (NS), at different time. Successful block was defined as complete sensory blockade combined with painless during surgical incision. Data were compared using Spearman test and multivariate logistical regression analysis.

RESULTS

Patients (184) were included (elective surgery=62%; emergency=38%). Failure rate was 10%. On multivariate logistical regression analysis, time to perform the block and NS anxiety score before starting the block were associated with block failure. Spielberger score correlated with NS anxiety score before puncture (Rho = 0,586, p<10(-4)). Anxiety level was increased in emergency context.

CONCLUSION

Patient's anxiety level before axillary brachial plexus block is a risk factor of failure, especially in emergency condition. We suggest anesthesiologists to evaluate patient anxiety prior to block performance. A specific anxiolytic treatment may be recommend in some cases.

Mu-opioid receptor (A118G) single-nucleotide polymorphism affects alfentanil requirements for extracorporeal shock wave lithotripsy: a pharmacokinetic-pharmacodynamic study

BACKGROUND

There are diverse reports concerning the single-nucleotide polymorphism (SNP) A118G in the gene coding for the mu-opioid receptor. This study assessed pharmacokinetic-pharmacodynamic relationships in patients with acute pain (water-immersed extracorporeal shock wave lithotripsy).

METHODS

Ninety-nine patients (ASA I-II, age 18-70) were assessed in this prospective observational study. Blinding was achieved by determining genotype only after the procedure. I.V. alfentanil was administered by patient-controlled administration (loading dose, 10 microg kg(-1); continuous infusion, 20 microg kg(-1) h(-1); bolus, 3 microg kg(-1); lockout time, 1 min); no other analgesic or sedating medication was used.

RESULTS

The allelic frequency was 15.2% in our population. The G118 SNP (AG/GG) was associated with a 27% increase in plasma alfentanil concentration (P=0.034), a 54% increase in alfentanil dose (P=0.009), a 47% increase in dose per kg body weight (P=0.004), a 55% increase in dose per kg corrected for stimulus intensity (P=0.002), a 112% increase in the numbers of attempted boluses (P=0.015), a 79% increase in the numbers of successful boluses (P=0.013), and a 153% increase in the numbers of failed boluses (P=0.042). Despite the increased alfentanil self-administration, the G118 SNP was associated with a 52% increase in verbal analogue pain scores over the same period of time (P=0.047).

CONCLUSIONS

We demonstrated increased opioid requirement for alfentanil in patients with the G118 SNP, who self-administered a higher dose, achieved higher plasma concentration, and yet complained of more severe pain. This observation suggests that G118 SNP impairs the analgesic response to opioids.

Median effective infusion dose (ED50) of alfentanil for monitored anesthesia care of percutaneous vertebroplasty of osteoporotic fractures

Percutaneous vertebroplasty (PVP) consists of injecting small quantities of orthopedic cement to consolidate pathologic vertebral bodies. The procedure is brief but painful during vertebral puncture and cement injection requiring either general anesthesia or monitored anesthesia care with opioids. The optimal dose of alfentanil in this setting is unknown. Therefore, we sought to determine its median effective dose (ED50, or analgesic efficacy in 50% of patients) during PVP in none intubated, spontaneously breathing patients. After approval and informed consent of the Institutional Review Board, 50 patients (American Society of Anesthesiologists II-III, age 50 to 80, weight: 53 to 82 kg) with osteoporotic vertebral fractures were enrolled. The patients were premedicated with oral hydroxyzine 100 mg and had skin infiltration with 50 mg lidocaine before vertebral puncture. The prone position was adopted and oxygen was provided via a facemask. Noninvasive cardiorespiratory variables were monitored. Pain was evaluated by a numerical pain scale (NPS) where 0 represents no pain and 10 the worst tolerable pain. Alfentanil infusion was started 30 minutes before vertebral puncture. The initial dose was 2.0 mg/h. Thereafter, a 0.05 mg/h decrease or increase was applied to the next patient if analgesia was effective (NPS: 3 or less) or not (NPS>3) according to the Dixon method. The bootstrap resampling technique was used to calculate the ED50 and its 95% confidence limits. The latter was 1.05 mg/h (95% confidence interval, 1.0-1.2). Transient apnea (n=2) and nausea/vomiting (n=3) were observed. Given the median body weight of the patients (65 kg), we conclude that 0.27 microg kg/min of alfentanil provides effective analgesia for PVP under monitored anesthesia care.

SUMMARY STATEMENT

PVP consists of injecting small quantities of orthopedic cement to consolidate pathologic vertebral bodies. The median effective dose (ED50) for pain relief during vertebral puncture and cement injection is 1.05 (95% confidence interval, 1.0-1.2) mg/h when infusion is started 30 minutes before the procedure. Given the median body weight of our study population (65 kg), this dose corresponds to 0.27 microg kg/min.

Remifentanil-propofol versus fentanyl-propofol for monitored anesthesia care during hysteroscopy

STUDY OBJECTIVE

To compare the efficacy of remifentanil-propofol with that of fentanyl-propofol for monitored anesthesia care during hysteroscopy.

DESIGN

Prospective, randomized study.

SETTING

Operating room and postanesthesia care unit of a university hospital.

PATIENTS

30 ASA physical status I and II adult patients undergoing hysteroscopic procedures.

INTERVENTIONS

After propofol infusion, patients received a bolus of remifentanil (group R, 0.5 microg/kg) or fentanyl (group F, 1 microg/kg) 4 minutes before starting the procedure and then received a continuous infusion of remifentanil (group R, 0.05 microg/kg per min) or bolus doses of fentanyl (group F, 0.5 microg/kg).

MEASUREMENTS AND MAIN RESULTS

Patients in group R had lower pain scores than patients in group F (0-0 vs 0-7, P < 0.05) and more stable blood pressures (74 +/- 15 vs 85 +/- 9 mmHg, P < 0.05) one minute after the start of the procedure. However, no differences were observed in other variables (recovery profiles and satisfaction scores).

CONCLUSION

Remifentanil seems to be a safe and effective analgesic adjunct for monitored anesthesia care of hysteroscopic surgery.

Patient-controlled sedation vs. anaesthetic nurse-controlled sedation for cataract surgery in elderly patients

BACKGROUND

Patient-controlled sedation (PCS) with propofol has been used successfully in various conditions, but controversies exist about its use in sedation of elderly patients for cataract surgery. This study evaluates the efficacy of anaesthetic nurse-controlled sedation (ACS) compared with PCS using the same device and the drug.

METHODS

All of the 153 elderly patients (aged 51-88 years) undergoing cataract surgery with a sub-Tenon's infiltration were assigned to receive ACS (n = 51) or PCS (n = 51) with propofol or no intra-operative sedation (control, n = 51). Propofol was administered with a bolus dose of 10 mg and a lockout interval of 1 min. Cognitive function, sedation, pain, anxiety, side effects and satisfaction of patients were evaluated.

RESULTS

The mean +/- SD doses of propofol administered were 34.9 +/- 8.8 mg and 30.1 +/- 30.4 mg in the groups ACS and PCS, respectively. The anxiety score was lower in both ACS and PCS groups compared with control group but was not different between the two groups. Patient's satisfaction was highest in PCS group, ACS group was the next, compared with non-sedated group. Other parameters were not different among the three groups.

CONCLUSIONS

Both ACS and PCS using propofol provided reduced anxiety compared with control, but patient's satisfaction was higher in the PCS group compared with ACS group.

Sedation and regional anaesthesia in the adult patient

This review discusses sedation for regional anaesthesia in the adult population. The first section deals with general aspects of sedation and shows that the majority of patients receiving sedation for regional anaesthesia are satisfied and would choose it again. Methods of assessing the level of sedation are discussed with emphasis on clinical measures. The pharmacology of the drugs involved in sedation is discussed, with propofol and remifentanil appearing to be the combination of choice for sedation in regional anaesthesia. The techniques for administering sedation are discussed and replacement of the traditional repeated boluses or continuous infusion with pharmacokinetic and patient-controlled systems is supported. Patient satisfaction studies suggest that patient-controlled systems are preferred.

The Effect of the Assignment of a Pre-Sedation Target Level on Procedural Sedation Using Propofol

The goal of this study was to determine if there is a difference in the achieved depth of sedation, the rate of respiratory depression, procedural difficulty, or patient perceived pain or recall between patients randomized to a pre-procedural target sedation level of moderate or deep procedural sedation using propofol during the reduction of fractures and dislocations in the Emergency Department (ED). This was a randomized, prospective study of adults undergoing procedural sedation (PS) with propofol for fracture or dislocation reduction in the ED between July 2003 and March 2004. Patients were randomized to a target sedation level of moderate or deep, using American Society of Anesthesiologists' definitions. Doses, vital signs, nasal end tidal CO(2) (ETCO(2)), pulse oximetry, and bispectral EEG analysis (BIS) scores were recorded. Respiratory depression was defined as a change in ETCO(2) >10, an oxygen saturation of <90% at any time, or an absent ETCO(2) waveform at any time. After the procedure, patients were asked if they perceived any pain or had any recall of the procedure. Physicians were asked to rate the difficulty of completing the reduction using a 100-mm visual analog scale (VAS). Respiratory depression rates were compared with chi-square tests, BIS and VAS scores were compared with t tests. Seventy-five patients were enrolled, 39 randomized to the target of moderate PS and 36 to the target of deep PS. No significant complications were noted. There were 25/36 (69%) of the patients assigned to the deep sedation target group who actually achieved a deep level of sedation and 21/39 (54%) of the patients assigned to the moderate sedation target group who actually achieved a moderate level of sedation (p = 0.40). Respiratory depression was seen in 19/39 (49%) patients with the moderate PS target and 18/36 (50%) with the deep PS target (p = 0.91). The mean minimum recorded BIS score was 67.7 (95% confidence interval [CI] 62.2-73.3) for the moderate PS target group and 59.2 (95% CI 55.1-64.2) for the deep PS target group (p = 0.03). There were 12/39 (31%) in the moderate PS target group and 4/36 (11%) in the deep PS target group who reported pain with or recall of the procedure (p = 0.04). The mean physician VAS for procedural difficulty was 34.0 (95% CI 23.7-44.3) for the moderate PS group and 28.8 (95% CI 18.4-39.2) for the deep PS group (p = 0.46). In this study, the assignment of a pre-procedural target sedation level of moderate or deep PS did not influence the level of sedation achieved, the rate of respiratory depression, the occurrence of complications, the time to return of baseline mental status, or the success of the procedure. It does not seem that the assignment of a pre-procedural target sedation level is an effective means of changing the outcome of ED PS.

Comparison of a Bolus of Fentanyl With an Infusion of Alfentanil During Target-Controlled Propofol Infusion in Third Molar Extraction Under Conscious Sedation

PURPOSE

This study was designed to compare hemodynamic changes, respiratory depression, and patient satisfaction between a bolus of fentanyl and an infusion of alfentanil during target-controlled propofol infusion in third molar extraction under conscious sedation.

PATIENTS AND METHODS

Forty patients were randomly assigned to receive either a bolus of fentanyl (n = 24) or an infusion of alfentanil (n = 16) in combination with target-controlled propofol infusion. Hemodynamic changes, respiratory depression, sedation, and cooperation scores were recorded during surgery and patient satisfaction scores were assessed after surgery.

RESULTS

Changes in mean blood pressure, heart rate, or oxygen saturation within and between the groups were not significant throughout the procedure. There were no significant differences in sedation, cooperation, and patient satisfaction scores between the 2 groups.

CONCLUSION

Because there was no difference in hemodynamic variables and patient satisfaction scores between a bolus of fentanyl and an infusion of alfentanil during target-controlled propofol infusion, both combinations are suitable for conscious sedation in third molar extraction.

A novel mixture of propofol, alfentanil, and lidocaine for regional block with monitored anesthesia care in ophthalmic surgery

STUDY OBJECTIVE

The purpose of this study is to determine the efficacy and safety of sedation/analgesia using a mixture of propofol, alfentanil, and lidocaine.

DESIGN

A retrospective case review was undertaken.

SETTING

This study took place at a university medical center.

PATIENTS

Eighty-nine American Society of Anesthesiologists physical status 1, 2, and 3 adult patients undergoing ophthalmic surgery with regional block and monitored anesthesia care were studied.

INTERVENTION

Six milliliters of propofol, 2 mL of alfentanil, and 2 mL of 2% lidocaine (6-2-2 mixture) were freshly mixed. The bolus dose was determined based on the patients' age: 5 microg/kg of alfentanil (and 0.3 mg/kg of propofol) for patients older than 75 years; the dose increased 1 mug/kg per 10-year decrease in age; and up to 9 microg/kg of alfentanil (0.54 mg/kg of propofol) for patients younger than 45 years. Regional block was performed at 1 minute after bolus completion. Blood pressure (BP), Sa(O2), electrocardiogram, capnography, clinical signs of sedation, responses to block, need for airway support, nausea and vomiting (N/V), pain due to propofol infusion, recall, and patient and surgeon satisfaction were recorded.

MEASUREMENTS AND MAIN RESULTS

Seventy-eight percent of patients achieved analgesia and sedation without adverse response to the block. Twelve percent achieved good analgesia and sedation with only eyebrow movement upon needle insertion. Twenty-seven percent had respiratory depression but were able to follow commands and maintain adequate ventilation. Two percent had brief apnea alleviated by chin lift or jaw thrust. None had pain because of propofol infusion or N/V. Before sedation, average systolic BP was significantly increased (P < 0.0001) compared with baseline. After sedation and block, systolic BP decreased 6% from baseline (P < 0.005).

CONCLUSION

Adjusted for age and weight, the dose of the 6-2-2 mixture met the sedation requirements for most patients. With a low incidence of need for airway support, no pain during infusion, and no N/V, this novel mixture of propofol, alfentanil, and lidocaine provided adequate analgesia and sedation as well as hemodynamic stability for ophthalmic surgery under regional block.

A comparison of fentanyl-propofol with a ketamine-propofol combination for sedation during endometrial biopsy

STUDY OBJECTIVE

The purpose of this study was to compare the clinical activities of ketamine and fentanyl when used in combination with propofol for outpatients undergoing endometrial biopsy. The investigated parameters were respiration, sedation, recovery rate, side effects, time to discharge, and patient satisfaction.

DESIGN

Prospective, randomized, double-blind study.

SETTING

University hospital.

PATIENTS

Forty American Society of Anesthesiologists physical status I and II patients (age range 38-61 years) scheduled for elective endometrial biopsy.

INTERVENTIONS

Patients received intravenous bolus doses of either fentanyl 1 microg/kg and propofol 1 mg/kg in (group 1 n = 20) or ketamine 0.5 mg/kg and propofol 1 mg/kg in (group 2 n = 20).

MEASUREMENTS

Heart rate, systolic and diastolic blood pressure, respiratory rate, and peripheral O(2) saturation were monitored in all patients. Depth of sedation was assessed by the Ramsay sedation score. The Aldrete score was used for postoperative recovery evaluation. The time to Aldrete score >/=8, side effects, and time to discharge were recorded.

MAIN RESULTS

Respiratory depression was observed in 5 patients from group 1 and 1 patient from group 2, but the difference was not significant (P > .05). Nausea, vertigo, and visual disturbances were more frequent in group 2 (P < .05). The time to Aldrete score >/=8 was similar in the 2 groups (6.2 +/- 3.5 minutes in group 1 and 7.0 +/- 3.1 minutes in group 2); the time to discharge was significantly longer in group 2 (71.2 +/- 9.7 minutes in group 1 and 115.2 +/- 25.6 minutes in group 2). Frequency of patient satisfaction was 95% in group 1 and 60% in group 2.

CONCLUSIONS

Hemodynamic change and degrees of sedation showed that fentanyl-propofol and ketamine-fentanyl combinations can be used safely in patients undergoing endometrial biopsy. However, with regard to side effects and patient satisfaction, the fentanyl-propofol was superior.

Remifentanil provides better analgesia than alfentanil during breast biopsy surgery under monitored anesthesia care

PURPOSE

To compare the analgesic effects of remifentanil and alfentanil during breast biopsy under monitored anesthesia care (MAC).

METHODS

Sixty patients received sedation with propofol (50 microg.kg(-1).min(-1)). After receiving a loading dose of opioid (either remifentanil 0.5 microg.kg(-1), or alfentanil 2.5 microg.kg(-1)), an infusion was initiated (remifentanil 0.05 microg.kg(-1).min(-1) or alfentanil 0.25 microg.kg(-1).min(-1)), and this was supplemented with local anesthetic infiltration. The pain was evaluated with a ten-point visual analogue scale (VAS) during local anesthetic infiltration and deep tissue dissection. Inadequate analgesia, defined as VAS scores > or = 5, was treated first with boluses of opioid (remifentanil group 10 microg or alfentanil group 50 microg) and if inadequate after two treatments with additional local anesthetic. Postoperative times were recorded including the times until discharge criteria were achieved and patient's actual discharge.

RESULTS

The pain scores were similar between the two groups during the initial injections of local anesthetic in the breast, however, patients in the remifentanil group had lower mean pain scores during deep tissue dissection (2.3 vs 4.3, P < 0.01). Patients in the remifentanil group required fewer rescue doses of opioid (1.9 vs 3.6, P < 0.03) and local anesthetic (5 vs 15, P < 0.006). The two study groups had comparable speed of recovery.

CONCLUSION

Remifentanil was a better opioid choice than alfentanil for breast biopsy under MAC at the doses studied, but it did not increase the rapidity in which patients recovered postoperatively.

Intravenous techniques in ambulatory anesthesia

The growing importance of ambulatory surgery during the past decade has led to the development of efficient anesthetic techniques in terms of quality and safety of anesthesia and recovery. In these challenging objectives, intravenous techniques have played an important role, as they provide safe, efficient, and cost-effective anesthesia in the ambulatory setting. Among the numerous intravenous drugs, propofol, with its fast and smooth onset of action, short duration of action, and low incidence of postoperative side effects appears to be the anesthetic of choice in this situation. The recent development of new techniques of administration (such as TCI, monitored anesthesia care, or patient-controlled sedation) and monitoring (such as the BIS and the availability of "hit and run" drugs such as remifentanil) will optimize intraoperative conditions and recovery, thus allowing faster home readiness in the ambulatory setting.

Sedation for outpatient endometrial biopsy: comparison of remifentanil-propofol and alfentanil-propofol

The purpose of the study was to compare the clinical activity of remifentanil or alfentanil under propofol sedation with regard to respiratory rate, sedation and recovery rate when used for outpatient endometrial biopsy. Patients were randomized to receive intravenously either bolus remifentanil 0.4 microgram/kg and propofol 1 mg/kg in the remifentanil group (n = 30), or bolus alfentanil 20 micrograms/kg and propofol 1 mg/kg in the alfentanil group (n = 30). Patients were monitored for heart rate, systolic and diastolic arterial pressure, peripheral O2 saturation (SpO2), respiration rate, and Aldrete sedation score. Pulse oximetry was used to monitor heart rate and SpO2 during endometrial biopsy. Apnoea was observed in five patients from the remifentanil group, and in three patients from the alfentanil group. The groups did not differ with regard to apnoea incidences. Times were recorded for orientation and Aldrete score > 8, and were similar between the two groups (13.20 +/- 3.64 min and 14.0 +/- 3.87 min in the remifentanil group, 14.7 +/- 3.64 min and 15.9 +/- 3.15 min in the alfentanil group, respectively). The sedative and analgesic combination of remifentanil-propofol does not offer any advantages compared with a combination of alfentanil-propofol with regards to respiration and recovery during sedation for outpatient endometrial biopsy.

Controversial issues in adult and paediatric ambulatory anaesthesia: is there a role for alpha-2 agonists in conscious sedation in adults and paediatric ambulatory surgical practice?

Ambulatory surgery has come to the fore in recent years, guided by the twin forces of healthcare economics and pharmacological innovations. In this review the authors will focus on alpha2-adrenergic agonists, a new class of sedative/analgesic agents and their possible application for conscious sedation in the ambulatory care setting. To put the alpha2-agonists into clinical context, we will discuss the currently available agents for general anaesthesia as well as for conscious sedation and their respective drawbacks. Thereafter we will compare and contrast the use of alpha2-agonists with clinically available agents, and speculate as to the direction this field is likely to take in the future.

Fast-tracking after immersion lithotripsy: general anesthesia versus monitored anesthesia care

Both monitored anesthesia care (MAC) and general anesthesia (GA) offer advantages over epidural anesthesia for immersion lithotripsy. We compared propofol-based MAC and desflurane-based GA techniques for outpatient lithotripsy. After receiving midazolam 2 mg IV, 100 subjects were randomly assigned to one of two anesthetic treatment groups. In the MAC group, propofol 50-100 microg. kg(-1). min(-1) IV was titrated to maintain an observer's assessment of alertness/sedation score of 2-3 (5 = awake/alert to 1 = asleep). Remifentanil 0.05 microg.kg(-1). min(-1) IV supplemented with 0.125 microg/kg IV boluses, was administered for pain control. In the GA group, anesthesia was induced with propofol 1.5 mg/kg IV and remifentanil 0.125 microg/kg IV and maintained with desflurane (2%-4% inspired) and nitrous oxide (60%). Tachypnea (respiratory rate >20 breaths/min) was treated with remifentanil 0.125 microg/kg IV boluses. In the GA group, droperidol (0.625 mg IV) was administered as a prophylactic antiemetic. Recovery times and postoperative side effects were assessed up to 24 h after the procedure. Compared with MAC, the use of GA reduced the opioid requirement and decreased movements and episodes of desaturation (<90%) during the procedure. Although the GA group took longer to return to an observer's assessment of alertness/sedation score of 5, discharge times were similar in both groups. We conclude that GA can provide better conditions for outpatient immersion lithotripsy than MAC sedation without delaying discharge.

IMPLICATIONS

A desflurane-based general anesthetic technique using the cuffed oropharyngeal airway device was found to be a highly acceptable alternative to propofol-based monitored anesthesia care sedation for outpatient immersion lithotripsy.

The use of a ketamine-propofol combination during monitored anesthesia care

Supplemental analgesics are commonly used to enhance analgesia and improve patient comfort during procedures performed under local anesthesia and sedation. Because the use of ketamine as an analgesic adjunct to propofol sedation has not been well established, we evaluated its impact on analgesia, sedation, and recovery after ambulatory surgery. One hundred female outpatients undergoing breast biopsy procedures under local anesthesia participated in this randomized, double-blinded, placebo-controlled study. After premedication with midazolam, 2 mg IV, patients received an infusion of a solution containing propofol (9.4 mg/mL) in combination with either placebo (saline) (Group 1) or ketamine, 0.94 mg/mL (Group 2), 1.88 mg/mL (Group 3), or 2.83 mg/mL (Group 4). The sedative infusion rate was varied to maintain a deep level of sedation (Observer Assessment of Alertness/Sedation score 4) and normal respiratory and hemodynamic functions. Sufentanil, 2.5 microg IV, "rescue" boluses were used as needed to treat patients' responses (if any) to local anesthetic infiltration or surgical stimulation. Ketamine produced a dose-dependent reduction in the "rescue" opioid requirements. However, there was an increase in postoperative nausea and vomiting, psychomimetic side effects, and delay in discharge times with the largest ketamine dosage (Group 4). The adjunctive use of ketamine during propofol sedation provides significant analgesia and minimizes the need for supplemental opioids. The combination of propofol (9.4 mg/mL)/ketamine (0.94-1.88 mg/mL) provides effective sedation/analgesia during monitored anesthesia care.

IMPLICATIONS

Ketamine, when used in subhypnotic dosages, may be an useful adjuvant to propofol sedation.