Remifentanil and propofol sedation for retrobulbar nerve block

We studied remifentanil and propofol for analgesia and sedation during the placement of an ophthalmic block. Eighty ASA I or II patients undergoing elective cataract surgery under a retrobulbar block in a rural camp setting were included in the study. Patients were randomly divided into four groups and received different drug combinations as follows: Group I--remifentanil 1 microg/kg, Group II--remifentanil 0.5 microg/kg and propofol 0.5 mg/kg, Group III--remifentanil 1 microg/kg with propofol 0.5 mg/kg and Group IV--saline 0.1 ml/kg. Patients were observed for degree of movement, sedation, pain, recall and respiratory depression. No patient in the study groups reported pain or displayed movement whereas most of the patients in the control group had significant pain during the placement of the block. Also, seven (35%) patients in the control group showed significant movement which may have led to failure of block in two patients and retrobulbar haemorrhage in one patient. Incidence of significant respiratory depression was maximum in Group III patients (60%), followed by Group I (20%) and least in Group II (5%). All patients in the study groups remained cooperative and obeyed commands except four patients in group III (OAA/S-4). Postoperatively, other than the control group, recall was maximum in Group I (55%) and least in Group II (5%). Hence, a combination of remifentanil 0.5 microg/kg with propofol 0.5 mg/kg as a bolus was considered to provide excellent relief of pain and anxiety with least adverse effects for the placement of ophthalmic blocks.     

Sudden unexpected sneezing during the insertion of peribulbar block under propofol sedation

Canadian Journal of Anesthesia/Journal canadien d'anesthésie - The author presents a case report where, following propofol sedation for a peribulbar block, sneezing was induced once the...     

A comparison of midazolam, alfentanil and propofol for sedation in oupatient intraocular surgery

PURPOSE: To determine the ideal sedative regimen for intraocular surgery under peribulbar or retrobulbar block. The addition of alfentanil and or propofol to midazolam was evaluated with regard to hemodynamic variables, respiratory rate, pain, anxiety, sedation, postoperative recovery and patient satisfaction. METHODS: Eighty two patients aged between 50 and 85 were recruited into this prospective, randomised, double blind study. Patients, in four groups, received 0.015 mg x kg(-1) midazolam, 5 microg x kg(-1) alfentanil and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 0.15 mg x kg(-1) propofol; 0.015 mg x kg(-1) midazolam and 5 microg x kg(-1) alfentanil or 0.015 mg x kg(-1) midazolam alone. Blood pressure, heart rate, respiratory rate, pain, anxiety and sedation scores were measured. Times to discharge from the Post Anesthesia Care Unit (PACU) and Day Surgery Unit (DSU) were documented. A 24 hr telephone interview was carried out to determine patient satisfaction. RESULT: Systolic blood pressure of patients in groups that had received alfentanil was 6% lower than that of patients who had not (P<0.05) at the time of insertion of intraocular block. Patients in the alfentanil groups also had lower respiratory rates during the first 15 min after drug administration, but all patients were given supplemental oxygen therefore oxygen saturation was unaffected. Pain scores of patients who had been given alfentanil were lower during the first postoperative hour than those who had not. CONCLUSION: The addition of alfentanil to midazolam is advantageous in providing sedation for insertion of intraocular block.     

Remifentanil versus propofol sedation for peribulbar anesthesia

The short onset and offset of remifentanil may allow for accurate dosing of sedative effect with few side-effects and rapid recovery. In this study, remifentanil is compared with propofol for sedation intraocular pressure hemodynamics and oxygen saturation, in patients undergoing cataract surgery with peribulbar block. After ethical committee approval, fifty patients scheduled for one eye cataract surgery were enrolled into the prospective study. Remifentanil infusion was initialized at a rate of 0.04 microg/kg/min, 10 min before peribulbar anesthesia in Remifentanil group (Group R). In Propofol Group (Group P), propofol infusion of 2 mg/kg/h was reduced to 1mg/kg/h. Intraocular pressures of the contralateral eye were measured before and after peribulbar anesthesia and at the end of the operation. Sedation scores (1-5), hemodynamic parameters and saturation were assessed at 5 minute intervals. Heart rate, intraocular pressure, saturation and sedation scores were similar between groups. Intraocular pressures decreased within time in both groups. There were significant changes in mean blood pressure after 5th min between groups (P < 0.05). The infusion of remifentanil or propofol for sedation provided adequate sedation, hemodynamic stability without increasing intraocular pressure during surgery in patients undergoing cataract surgery with peribulbar anesthesia.     

A comparison of propofol and remifentanil for sedation and limitation of movement during periretrobulbar block

STUDY OBJECTIVES: To compare clinical conditions in patients sedated with propofol or remifentanil during combined peri-bulbar and retrobulbar block (PRBB) for cataract surgery. DESIGN: Prospective, randomized, double-blind study. SETTING: Private clinic. PATIENTS: 106 ASA physical status I and II patients scheduled for cataract surgery. INTERVENTIONS: Patients were randomized to receive either 0.5 mg/kg propofol (Group P) or 0.3 microg/kg remifentanil (Group R) as an intravenous (IV) bolus 1 minute prior to PRBB. At the same time, patients in both groups also received 0.5 to 1 mg midazolam IV. Movement of the hands, arms, head, and eyes were counted during each stage of the procedure by an observer who was blinded to the sedation used. Heart rate (HR), blood pressure (BP), respiratory rate (RR), expiratory CO(2) (PECO(2)), and hemoglobin oxygen saturation (SaO(2)) were recorded every minute for 10 minutes after the PRBB. Anesthetic complications, recall, and the pain experienced with the block and surgery were compared between the two groups. Means and variance of the results were compared with one-way analysis of variance and Fisher's exact test. MEASUREMENTS AND MAIN RESULTS: Movements of the hands, arms, and head were significantly greater in Group P during all stages of the block. Almost no movements were recorded in the remifentanil group. Immediately after the PRBB (1 to 6 min), HRs were higher in Group P (73 +/- 11 bpm vs. 67 +/- 10 bpm; p = 0.0075), whereas the RRs were slower in Group R for the period 1 to 5 minutes after the PRBB (16 +/- 5 breaths/min vs.14 +/- 4 breaths/min; p = 0.0206). At these times, the mean PECO(2) was higher in Group R (36 +/- 7 mmHgvs. 32 +/- 9 mmHg; p = 0.0125). Nineteen patients in the propofol group sneezed during the medial peribulbar injection compared with none in the remifentanil group. Anesthetic and surgical complications were unremarkable and similar for the two groups. CONCLUSIONS: Respiratory depression with remifentanil was mild and not clinically significant. Remifentanil sedation for this application was superior to sedation with propofol.     

Inadvertent globe perforation during peribulbar anaesthesia and sedation with propofol

Sedation has been used widely for reducing patient anxiety during peribulbar block for ocular surgery. We report the case of a patient in whom a spontaneous move after injection of propofol for peribulbar block resulted in a globe perforation.     

Bispectral index monitoring during sedation with sevoflurane, midazolam, and propofol.

BACKGROUND: Bispectral Index (BIS) has been used to measure sedation depth. Ideally, to guide anesthetic management, range of BIS scores at different sedation levels should not overlap, and BIS should be independent of drug used. This study assessed ability of BIS to predict sedation depth between sevoflurane, propofol, and midazolam. Quality of recovery was also compared. METHODS: Patients undergoing surgery with local or regional anesthesia and sedation were randomized to sevoflurane (n = 23), midazolam (n = 21), or propofol (n = 22). Sedation was titrated to Observers's Assessment of Alertness-Sedation score of 3 (responds slowly to voice). BIS and Observers's Assessment of Alertness-Sedation were measured every 5 min. BIS prediction probability (PK) was compared between drugs. Recovery was assessed by BIS and Digit Symbol Substitution and memory tests. RESULTS: Bispectral Index of responders to voice was significantly different from nonresponders (86 +/- 10 vs. 74 +/- 14, mean +/- SD; P < 0.001) However, wide variability and overlap in BIS were observed (25th-75th percentile, responders vs. non-responders: 79-96 vs. 65-83). BIS of responders was different for sevoflurane versus propofol and midazolam. BIS was a better predictor of propofol sedation than sevoflurane or midazolam (PK = 0.87 +/- 0.11, 0.76 +/- 0.01, and 0.69 +/- 0.02, respectively; P < 0.05). At 10 min after the procedure, 76, 48, and 24% of sevoflurane, propofol, midazolam patients, respectively, returned to baseline Digit Symbol Substitution scores (P < 0.05). Excitement-disinhibition occurred in 70, 36, and 5% of sevoflurane, propofol, and midazolam patients, respectively (P < 0.05). CONCLUSION: Individual BIS scores demonstrate significant variability, making it difficult to predict sedation depth. The relation between BIS and sedation depth may not be independent of anesthetic agent. Quality of recovery was similar between drugs, but excitement occurred frequently with sevoflurane.     

A cost comparison of methohexital and propofol for ambulatory anesthesia.

Methohexital is eliminated more rapidly than thiopental, and early recovery compares favorably with propofol. We designed this study to evaluate the recovery profile when methohexital was used as an alternative to propofol for the induction of anesthesia before either sevoflurane or desflurane in combination with nitrous oxide. One hundred twenty patients were assigned randomly to one of four anesthetic groups: (I) methohexital-desflurane, (II) methohexital-sevoflurane, (III) propofol-desflurane, or (IV) propofol-sevoflurane. Recovery times after the anesthetic drugs, as well as the perioperative side effect profiles, were similar in all four groups. A cost-minimization analysis revealed that methohexital was less costly for the induction of anesthesia. At the fresh gas flow rates used during this study, the costs of the volatile anesthetics for maintenance of anesthesia did not differ among the four groups. However, at low flow rates (< or = 1 L/min), the methohexital-desflurane group would have been the least expensive anesthetic technique. In conclusion, methohexital is a cost-effective alternative to propofol for the induction of anesthesia in the ambulatory setting. At low fresh gas flow rates, the methohexital-desflurane combination was the most cost-effective for the induction and maintenance of general anesthesia. Implications: Using methohexital as an alternative to propofol for the induction of anesthesia for ambulatory surgery seems to reduce drug costs. When fresh gas flow rates < or = 1 L/min are used, the combination of methohexital for the induction and desflurane for maintenance may be the most cost-effective general anesthetic technique for ambulatory surgery.     

The cost-effectiveness of methohexital versus propofol for sedation during monitored anesthesia care

We designed this study to test the hypothesis that methohexital is a cost-effective alternative to propofol for sedation during local anesthesia. Sixty consenting women undergoing breast biopsy procedures under local anesthesia were randomly assigned to receive an infusion of either propofol (50 microg x kg(-1) x min(-1)) or methohexital (40 microg x kg(-1) x min(-1)). The sedative infusion rate was titrated to maintain an observer's assessment of alertness/sedation (OAA/S) score of 3 (with 1 = awake/alert to 5 = asleep). Fentanyl 25 microg i.v. was administered as a "rescue" analgesic during the operation. We assessed the level of sedation (OAA/S score), vital signs, time to achieve an OAA/S score of 3 at the onset and a score of 1 after discontinuing the infusion, discharge times, perioperative side effects, and patient satisfaction. The direct cost of methohexital was lower than that of propofol, based on the milligram dosage infused during the operation. The sedative onset (to achieve an OAA/S score of 3) and the recovery (to return to an OAA/S score of 1) times, as well as discharge times, did not differ between the two groups. Patients receiving methohexital had a significantly lower incidence of pain on initial injection compared with those receiving propofol (10% vs 23%). Because the use of methohexital (29.4 +/- 2.7 microg x kg(-1) x min(-1)) for sedation during breast biopsy procedures has a similar efficacy and recovery profile to that of propofol (36.8 +/- 15.9 microg x kg(-1) x min(-1)) and is less costly based on the amount infused, it seems to be a cost-effective alternative to propofol for sedation during local anesthesia. However, when the cost of the drug infused and drug wasted was calculated, there was no difference in the overall drug cost. Implications: When administered to maintain a stable level of sedation during local anesthesia, methohexital is an acceptable alternative to propofol. However, the overall drug costs were similar with the two drugs.     

A comparison of midazolam and diazepam for sedation during locoregional anesthesia

Midazolam is a recently introduced benzodiazepine with a half life of 1-4 hours. Midazolam (0.15 mg/kg) has been compared with diazepam (0.2 mg/kg) for sedation during locoregional anesthesia in 60 premedicated patients. No difference among the two groups for heart rate, bloodpressure, respiratory rate and incidence, and duration of apnoea was noticed after an i.v. bolus administration. The recovery time was equal in both groups. Midazolam was significantly less painful at injection. The sedation pattern between both groups is only different at 60 minutes, where more better sedated patients are seen in the midazolam group. Except the pain at injection and a better sedation pattern after 60 min. the differences in the other parameters are only borderline.     

A comparison of propofol and midazolam in sedation of mechanically-ventilated postoperative patients]

To compare the quality of sedation using propofol (n = 8) vs midazolam (n = 7) we evaluated their effectiveness, safety, and recovery time after their continuous infusion in patients who required mechanical ventilation after cervical spine surgery. We also calculated the cost of drugs used during the mechanical ventilation. In addition, processed electroencephalogram (pEEG) was monitored employing spectral edge frequency 90 (SEF 90) as an indicator of sedation. Both drugs produced good sedation without any complication. The patients who had received propofol were extubated significantly earlier than those who had received midazolam (P; 35 +/- 18 mins, M; 97 +/- 55 mins). However, the mean drug cost in the propofol group was five times higher than that in the midazolam group (P; yen 15,881 +/- 7,788, M; yen 3,355 +/- 1,187). There was no correlation between the value of SEF 90 and the depth of sedation during mechanical ventilation. In conclusion, propofol exhibited the shorter recovery time after cessation of the continuous infusion than midazolam, but it costed five times compared with midazolam. SEF 90 failed to indicate the depth of sedation during mechanical ventilation.     

A comparison of target-controlled therapy with patient-controlled administration of propofol combined with midazolam for sedation during dental surgery

Forty anxious day case patients undergoing extraction of third molar teeth under local anaesthesia with sedation, were studied in a randomised double-blind controlled trial. A target-controlled infusion of propofol was compared with patient-controlled propofol for sedation, combined with a small dose of midazolam to improve amnesia. The objectives of the study were to measure the total dose of propofol used by the two groups and assess recovery and patient satisfaction. The mean dose of propofol used in the patient-controlled sedation group was significantly less than the target-controlled group (p < 0.00007). Five patients became over-sedated in the target-controlled group compared with none in the patient-controlled group. Only one of the three tests of performance showed that the target-controlled patients were more sedated. Patient satisfaction was high in both groups despite a greater recollection of events in the patient-controlled group.     

Propofol versus propofol-ketamine sedation for retrobulbar nerve block: comparison of sedation quality, intraocular pressure changes, and recovery profiles.

We compared sedation quality, intraocular pressure (IOP) changes, and recovery profiles in patients who received propofol or propofol-ketamine sedation during placement of the retrobulbar nerve block (RBB). Seventy elderly patients undergoing cataract extraction according to a prospective, randomized, double-blinded protocol were preoperatively evaluated with a Mini-Mental State examination and baseline IOP. A hypnotic dose was provided with either propofol (Group P) or a propofol-ketamine (Group PK) combination. The IOP measurement was repeated, and the surgeon initiated the RBB. Supplemental study drug was given if needed. The level of sedation was considered acceptable if the patient exhibited minimal or no movement and grimacing with needle insertion. Patients were evaluated in terms of quality of sedation, cardiopulmonary stability, and recovery profile. Compared with patients in Group P, patients in Group PK had a significantly faster onset of acceptable sedation (Group P 235 +/- 137 s versus Group PK 164 +/- 67 s) and required significantly less supplemental sedation (Group P 1.1 +/- 1.9 mL versus Group PK 0.15 +/- 0.3 mL). Additionally, none of the Group PK patients required ventilatory assistance, but two patients in Group P required assisted mask ventilation. In conclusion, the addition of ketamine (13.2 +/- 3.3 mg) to propofol (44 +/- 11 mg) decreased the hypnotic requirement and improved the quality of sedation without prolonging recovery. Implications: Anesthesiologists frequently perform retrobulbar blocks while simultaneously providing sedation. Using ketamine to supplement propofol sedation provided a faster onset and improved the quality of sedation during the retrobulbar block procedure.     

Conscious sedation for interventional neuroradiology: a comparison of midazolam and propofol infusion

Purpose

The aim of this study was to compare two conscious sedation techniques, midazolam (M) and propofol (P), for interventional neuroradiology by assessment of the incidence of complications and satisfaction scores.

Methods

Forty patients were randomized to receive 0.75 μg · kg^?1 fentanyl and a M or P bolus followed by an infusion; (M I5 μg · kg^?1 + 0.5 μg · kg^?1 · min^?1: P 0.5 mg · kg^?1 + 25 μg · kg^?1 min^?1). The incidences of complications and untoward events requinng intervention were documented. These included respiratory depression, excessive pain, inappropriate movements and the inability to examine the patient. The satisfaction of the anaesthetic technique from the perspective of both the neuroradiologist and the patient was scored.

Results

The incidence and types of complications were not different between the two groups. Pain occurred in 12 patients (6M, 6P), inappropriate movements in 17 (7M, 10P) and respiratory changes in 10 patients (2M, 8P).

Conclusions

Both techniques were satisfactory and the incidence of complications was similar for both groups.     

Anaesthesia for cardioversion. A comparison between propofol, thiopentone and midazolam

This study compares the induction and recovery characteristics, haemodynamic changes and side effects of propofol, thiopentone and midazolam when used as the anaesthetic agents for cardioversion. Recovery after midazolam was significantly longer (p less than 0.05) than with either thiopentone or propofol. There was no difference in the recovery times between thiopentone and propofol. There was a significant decrease in mean arterial pressure 2 minutes after induction with propofol and midazolam. Three patients each in the thiopentone and propofol groups needed assisted ventilation because of apneoea, and four patients each in the propofol and midazolam groups had low Spo2 values (less than 95%). Flumazenil was used to reverse the effects of midazolam in eight patients and five of these were still drowsy 4 hours after the procedure. This study indicates that thiopentone is the most satisfactory agent for anaesthesia for cardioversion.     

Patient-controlled sedation for cataract surgery using peribulbar block

Patients undergoing cataract surgery using peribulbar block were allocated randomly to self-administer doses of either midazolam 0.1 mg or propofol 3.3 mg without a lock-out facility; in the control group the syringe was charged with saline, not as a placebo, but to "blind" the surgeon and the nurse observer. For midazolam and propofol, median doses were 2.54 (0.1-6.0) mg and 87.4 (0-145) mg, respectively. Patient- controlled sedation significantly reduced the level of anxiety, with median visual analogue anxiety scores in the midazolam, propofol and saline groups of 5 (0-38) mm, 5 (0-25) mm and 15 (0-92) mm, respectively (P < 0.05). Some patients did not administer the sedative when available while others in the saline group would have benefited from anxiolytic drugs. While both drugs prevented an increase in heart rate, only midazolam prevented an increase in arterial pressure during surgery.      

Propofol and alfentanil for sedation during placement of retrobulbar block for cataract surgery

Study Objective: To determine if the addition of alfentanil to propofol is more effective than propofol alone to provide adequate conditions for placement of a retrobulbar block prior to cataract surgery.Design: Randomized, double-blinded study.Setting: Outpatients at a university hospital.Patients: 40 adult ASA physical status I, II, and III outpatients scheduled for elective cataract surgery.Interventions: Patients were randomly assigned to receive one of four drug combinations prior to the placement of a retrobulbar block: Group 1, propofol alone; Group 2, alfentanil 5 μg/kg plus propofol; Group 3, alfentanil 10 μg/kg plus propofol; Group 4, alfentanil 15 μg/kg plus propofol. All patients were preoxygenated by face mask for two minutes prior to drug administration. The quality of conditions for block placement were determined by: (1) assessing the amount of movement by the patients while the block needle was in place, (2) cooperativeness of the patients during the operation, (3) hemodynamic side effects, (4) incidence and severity of respiratory depression, (5) incidence of nausea and vomiting, (6) recall of placement of the block, and (7) time to discharge from the hospital.Measurements and Main Results: The addition of alfentanil to propofol for sedation prior to placement of the retrobulbar block resulted in a dose-dependent reduction in movement by the patients. However, the highest dose of alfentanil (15 μg/kg) resulted in the greatest frequency (40% of the patients in this group) of respiratory depression (SpO₂ < 90%). All patients were cooperative during the operation and responsive to verbal command within 5 minutes of placement of the block. In addition, all of the patients denied being nauseated, having vomited, or recalling block placement in the recovery room or the next day.Conclusions: The combination of alfentanil and propofol may be used to sedate patients in order to limit movement and provide a cooperative, alert patient with stable hemodynamics and limited respiratory depression during placement of retrobulbar block prior to ophthalmic surgery. However, excessive dosage of these drugs may result in hazardous respiratory depression in this patient population.     

Sedation for vitreoretinal surgery: a comparison of anaesthetist-administered midazolam and patient-controlled sedation with propofol

Local anaesthesia is increasingly being used for vitreoretinal surgery, but the optimal technique for sedation remains unclear. Anaesthetist-administered midazolam, which is often used, was compared in this study to patient-controlled sedation with propofol in 43 patients undergoing 50 vitreoretinal procedures. A variety of patient, anaesthetist and surgical endpoints were measured. There were no significant outcome differences between the two agents except that midazolam produced more amnesia for the local anaesthetic eye block. However, several outcomes and the observations in patients who experienced both agents showed a trend in favour of propofol for intraoperative sedation. We conclude that both approaches are safe and that patient-controlled sedation with propofol is at least as satisfactory as anaesthetist-administered midazolam.     

Comparison of recovery of propofol and methohexital sedation using an infusion pump.

Two sedative anesthetic agents administered by an infusion pump were compared during third molar surgery. Forty American Society of Anesthesiologists (ASA) class I or II volunteers were randomly allocated to two groups. All subjects received supplemental oxygen via a nasal hood, fentanyl (0.0007 mg/kg intravenous [i.v.] bolus), and midazolam (1 mg/2 min) titrated to effect. Patients then received either 0.3 mg/kg of methohexital or 0.5 mg/kg of propofol via an infusion pump. Upon completion of the bolus, a continuous infusion of 0.05 mg/kg/min methohexital or 0.066 mg/kg/min propofol was administered throughout the procedure. Hemo-dynamic and respiratory parameters and psychomotor performance were compared for the two groups and no significant differences were found. The continuous infusion method maintained a steady level of sedation. Patients receiving propofol had a smoother sedation as judged by the surgeon and anesthetist.