Randomized, Single-Blind, Comparative Study of Remimazolam Besylate vs Propofol for Facial Plastic Surgery

BACKGROUND

Use of local anesthesia and conscious sedation with a combination of a sedative and anesthetic drug during a surgical procedure is an approach designed to avoid intubation, which produces fewer adverse events compared to general anesthesia. In the present study, a comparison was made between the efficacy and safety of remimazolam besylate and propofol for facial plastic surgery.

OBJECTIVES

The objective was to evaluate the clinical efficacy, comfort, and incidence of adverse events of remimazolam compared with propofol combined with alfentanil in outpatient facial plastic surgery.

METHODS

In this randomized, single-blind, single-center, comparative study, facial plastic surgery patients were randomly divided into remimazolam-alfentanil (n = 50) and propofol-alfentanil (n = 50) groups for sedation and analgesia. The primary endpoint was the incidence of hypoxemia, while secondary endpoints included efficacy and safety evaluations.

RESULTS

There were no significant differences regarding the surgical procedure, sedation and induction times, pain and comfort scores, muscle strength recovery, heart rate, respiratory rate, and blood pressure, but the dosage of alfentanil administered to the remimazolam group (387.5 μg) was lower than that for the propofol group (600 μg). The incidence of hypoxemia (P = .046) and towing of the mandibular (P = .028), as well as wake-up (P = .027) and injection pain (P = .008), were significantly higher in the propofol group than the remimazolam group.

CONCLUSIONS

Remimazolam and propofol had similar efficacies for sedation and analgesia during facial plastic surgery, but especially the incidence of respiratory depression was significantly lower in patients given remimazolam.

LEVEL OF EVIDENCE: 2

Safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation of elderly patients undergoing ERCP

BACKGROUND

Proper sedation of patients, particularly elderly individuals, who are more susceptible to sedation-related complications, is of significant importance in endoscopic retrograde cholangiopancreatography (ERCP). This study aims to assess the safety and efficacy of a low-dose combination of midazolam, alfentanil, and propofol for deep sedation in elderly patients undergoing ERCP, compared to a group of middle-aged patients.

METHODS

The medical records of 610 patients with common bile duct stones who underwent elective ERCP under deep sedation with a three-drug regimen, including midazolam, alfentanil, and propofol at Shandong Provincial Third Hospital from January 2023 to September 2023 were retrospectively reviewed in this study. Patients were categorized into three groups: middle-aged (50-64 years, n = 202), elderly (65-79 years, n = 216), and very elderly (≥ 80 years, n = 192). Intraoperative vital signs and complications were compared among these groups.

RESULTS

The three groups showed no significant difference in terms of intraoperative variation of systolic blood pressure (P = 0.291), diastolic blood pressure (P = 0.737), heart rate (P = 0.107), peripheral oxygen saturation (P = 0.188), bispectral index (P = 0.158), and the occurrence of sedation-related adverse events including hypotension (P = 0.170) and hypoxemia (P = 0.423).

CONCLUSION

The results suggest that a low-dose three-drug regimen consisting of midazolam, alfentanil, and propofol seems safe and effective for deep sedation of elderly and very elderly patients undergoing ERCP procedures. However, further studies are required to verify these findings and clarify the benefits and risks of this method.

Comparison of ciprofol-alfentanil and propofol-alfentanil sedation during bidirectional endoscopy: A prospective, double-blind, randomised, controlled trial

BACKGROUND

Although propofol is widely used for gastrointestinal endoscopic sedation, cardiopulmonary adverse events remain common. Ciprofol is a new intravenous anaesthetic agent demonstrating respiratory and hemodynamic stability.

AIMS

This study aimed to clarify the benefits of ciprofol combined with alfentanil in bidirectional endoscopy (esophagogastroduodenoscopy followed by colonoscopy) to reduce adverse events and improve post-endoscopic recovery.

METHODS

A total of 185 patients scheduled to undergo bidirectional endoscopy were randomly divided into two groups: ciprofol combined with alfentanil or propofol combined with alfentanil. All patients received 7 µg/kg alfentanil intravenously before the study drugs were administered. The propofol group received a bolus of 1.2 mg/kg (0.12 ml/kg) propofol intravenously, whereas the ciprofol group received a bolus of 0.3 mg/kg (0.12 ml/kg) ciprofol intravenously. The primary outcome was the proportion of patients with cardiopulmonary adverse events (i.e., any one of the airway obstruction, apnoea, hypotension, hypertension, bradycardia, tachycardia or arrhythmias).

RESULTS

Compared with propofol, ciprofol reduced cardiopulmonary adverse events by 43.51 % (34.4% vs. 60.9 %, P <0.001), mitigated respiratory adverse events by 54.74 % (17.2% vs. 38.0 %, P = 0.002) overall and by 59.05 % (12.9% vs. 31.5 %, P = 0.002) during the induction period.

CONCLUSIONS

Ciprofol can significantly decrease respiratory depression events and provides a better sedative efficacy than propofol with higher recovery quality and satisfaction.

Use of Remimazolam Combined With Alfentanil for Plastic Surgery Anesthesia Cases: A Clinical Trial

OBJECTIVE

This study aims to observe the safety and effectiveness of remimazolam benzenesulfonate combined with alfentanil for painless and comfort anesthesia in plastic surgery.

METHODS

Two hundred patients with American Society of Anesthesiologists (ASA) I-II for elective facial autologous lipofilling + autologous liposuction (thigh or abdomen) plastic surgery in our hospital were selected. One hundred patients received comfort anesthesia (observation group) on odd-numbered day of surgery, and other 100 patients received painless anesthesia (control group) on even-numbered day. Patients in both groups were given slow injection of remimazolam benzenesulfonate 0.1 mg/kg and alfentanil 5 μg/kg to induce sleep before local anesthesia. Depending on body action reaction to surgical stimulation, patients in the observation group were received with remimazolam 0.05 mg/kg and alfentanil 2.5 μg/kg for maintenance until the end of surgery after local anesthesia, and patients in the control group received with remimazolam 0.25 to 0.5 mg/kg/h and alfentanil 25 to 50 μg/kg/h in continuous pumps. Time to fall asleep, sedation score, time to end of medication, time to open eyes, recovery score, and the presence of body movement, glossoptosis, arousal or jaw support during hypoxia, hypotension, bradycardia, operation time, total amount of remimazolam and alfentanil used, and the presence of postoperative complications such as pruritus, dizziness, nausea, and vomiting were recorded in both 2 groups.

RESULTS

There were no significant differences in the preoperative vital sign parameters as mean arterial pressure, heart rate, and oxygen saturation between 2 groups ( P > 0.05). Intraoperative mean arterial pressure and heart rate were significantly lower in both groups compared with preoperative ( P < 0.05), but there was no statistically significant between the 2 groups ( P > 0.05). There was no significant decrease in oxygen saturation in both groups under the condition of intraoperative oxygen inhalation ( P > 0.05). There was no significant difference between the 2 groups in the incidence of adverse reactions, such as intraoperative body movement induced by skin cutting, glossoptosis requiring jaw thrust, postoperative pruritus, dizziness, nausea, and vomiting ( P > 0.05). There was no statistically significant difference in time to fall asleep, sedation score during local anesthesia, time to open eyes after stopping anesthetics, and recovery score between the 2 groups ( P > 0.05). Meanwhile, the total amount of remimazolam and alfentanil use was significantly reduced in patients in the observation group compared with the control group ( P < 0.05).

CONCLUSIONS

Remimazolam benzenesulfonate combined with alfentanil can be used as a comfort anesthesia and painless anesthesia protocol in plastic surgery, which has the advantages of rapid onset of action, safety and comfort for patients, rapid recovery, and good cooperation. Furthermore, the protocol of remimazolam benzenesulfonate combined with alfentanil used in the observation group can significantly reduce the total amount of remimazolam and alfentanil used.

Efficacy and Safety of the Remimazolam-Alfentanil Combination for Sedation During Gastroscopy: A Randomized, Double-blind, Single-center Controlled Trial

PURPOSE

Propofol infusion is a popular single drug of choice for sedation in the gastrointestinal endoscopy suite. Drug combinations are more beneficial than single-drug regimens in gastroscopy sedation. However, the cardiopulmonary complications of propofol sedation raise concern. Remimazolam is a novel, ultra-short-acting benzodiazepine sedative, and alfentanil is a weak opioid. During endoscopic procedures, remimazolam is an effective and safe sedative procedure. No synergistic effect has been reported when remimazolam was combined with alfentanil in gastroscopy sedation. Here, we evaluated the effective dose, sedative efficacy, and safety of the remimazolam-alfentanil combination in gastroscopy sedation and compared the results with those of the propofol-alfentanil combination.

METHODS

This study was conducted in two parts. In Part 1, Dixon's up-and-down method (sequential distribution) was adopted for determining the 95% effective dose (ED95) (95% CI) and 95% CI of remimazolam combined with 5 µg/kg alfentanil. In Part 2, after obtaining the predictive remimazolam ED95, 161 patients were randomized into the remimazolam group (remimazolam-alfentanil) and the propofol group (propofol-alfentanil). The effectiveness of the drug combinations was measured according to successful sedation parameters. Changes in vital signs and the appearance of adverse events were used to assess the safety of drug combinations. Evaluation of patient and physician satisfaction was included as quality indicators of treatment.

RESULTS

Baseline demographic and clinical characteristics were comparable between the 2 parts of the study. The ED95 of remimazolam in inhibiting a positive response to gastroscopy placement into the pharyngeal cavity was 0.33 mg/kg (95% CI, 0.289 to 1.023). The procedure success rate was 97.53% in the remimazolam group and 97.50% in the propofol group. The difference in the success rate of the procedure between the remimazolam and propofol groups was 0.03% (95% CI, -2.5 to 2.4). However, the incidence of injection pain, hypotension, respiratory depression, and dizziness was lower in the remimazolam group compared with the propofol group (P < 0.05). Furthermore, patients from the propofol group were more likely to be drowsy, and their work efficiency was reduced the day after leaving the hospital, whereas patients in the remimazolam group were less affected (P < 0.05).

IMPLICATIONS

The ED95 of remimazolam was 0.33 mg/kg when it was combined with alfentanil (5 µg/kg) for gastroscopy sedation. The sedation strategy of remimazolam-alfentanil has noninferior efficacy, fewer adverse effects, and a better postoperative recovery process than propofol-alfentanil for patients undergoing gastroscopy. Chinese Clinical Trials Registry identifier: ChiCTR2100051565.

Efficacy and safety of remifentanil for endoscopic ultrasound-guided tissue acquisition: a single center retrospective study

BACKGROUND

Remifentanil is a rapid onset and rapid recovery opioid. The combination of remifentanil and propofol for deep sedation decreases the incidents of movement, cough, and hiccup. We evaluated the efficacy and safety of remifentanil during endoscopic ultrasound-guided tissue acquisition.

METHODS

We retrospectively reviewed patients in whom endoscopic ultrasound-guided tissue acquisition was performed for solid mass lesions of the upper gastrointestinal tract and adjacent organs. All patients were premedicated with midazolam (2 mg), and target-controlled infusion of propofol, opioid, and Bispectral Index (BIS) monitoring were administered as necessary to maintain moderate-to-deep sedation. The opioids used were a bolus of alfentanil or remifentanil infusion. The discharge time, consumption of propofol and opioid, adverse events, diagnostic accuracy, and sensitivity and specificity for malignancy, were compared.

RESULTS

Tissue acquisition was achieved in 123 patients (alfentanil group, n = 64; remifentanil group, n = 59). The discharge time of the remifentanil group (16.5 ± 3.2 min) was significantly shorter than that of the alfentanil group (19.0 ± 4.9 min, P = 0.001). The consumption of propofol, adverse events, diagnostic accuracy, sensitivity, and specificity for malignancy in the alfentanil group were not significantly different from those in the remifentanil group.

CONCLUSIONS

Use of alfentanil or remifentanil for target-controlled infusion of propofol-BIS monitoring can provide good sedative and diagnostic quality for endoscopic ultrasound-guided tissue acquisition. However, remifentanil resulted in faster recovery than alfentanil.

Sedoanalgesia for cardioversion: comparison of alfentanil, remifentanil and fentanyl combined with propofol and midazolam: a prospective, randomized, double-blind study

OBJECTIVE

Electrical cardioversion (EC) is a short but painful procedure to restore sinus rhythm. The aim of this study is to compare the effect of fentanyl, remifentanil and alfentanil in association with propofol and midazolam for elective EC.

PATIENTS AND METHODS

Ninety-nine patients older than 18-years, American Society of Anesthesiologists I/II/III grades undergoing elective EC were randomized into 3 groups. All patients received 2 mg midazolam and propofol (0.5 mg/kg). Group A received alfentanil (5 µg/kg i.v. bolus), Group F received fentanyl (0.5 µg/kg i.v. bolus) and Group R received remifentanil (0.25 µg/kg i.v. bolus). Hemodynamics and respiratory variables [Heart rate (HR), systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), SpO2, respiratory rate (RR)], and Modified Aldrete recovery score (MARS) were assessed at six different time points (baseline, right after EC, and 3rd min, 5th min, 10th min, 30th min following EC). Also, induction times (time to reach RSS to 5) and recovery times (time to reach MARS to 8) were recorded. The incidence of respiratory depression, bradycardia, hypotension and adverse effects were also recorded.

RESULTS

Hemodynamic variables were similar in all groups. SpO2 values in Group R were significantly lower at 3rd min (p = 0.005). Induction and recovery times were longest in Group F. There were significant differences at 3rd, 5th and 10th minute MARS values between groups. The incidence of hypotension and bradycardia were similar in all groups (p > 0.05) but respiratory depression was higher in Group R (p = 0.047).

CONCLUSIONS

Propofol alfentanil combination has more beneficial advantages in their rapid onset, early recovery time and less respiratory depression than remifentanil and fentanyl.

Comparison of the incidence and severity of cough after alfentanil and remifentanil injection

BACKGROUND

Intravenous administration of fentanyl derivatives can induce cough paradoxically. This study examined the incidence and severity of cough after a bolus of alfentanil and remifentanil.

METHODS

Four hundred and sixty-five patients, aged 18-70 years, were allocated randomly to three groups to receive alfentanil 10 microg/kg, remifentanil 1 microg/kg or an equal volume of 0.9% saline intravenously over 10 s. Any episode of cough was classified as coughing and graded as mild (1-2), moderate (3-4) or severe (5 or more).

RESULTS

The overall incidence of cough was higher in the opioid groups than in the saline group. The remifentanil group [39/150 patients; 26.0% (95% CI, 19.6-33.6%)] showed a higher incidence than the alfentanil group [11/152 patients; 7.2% (95% CI, 0.4-12.6%)] (P<0.001). There was no significant difference in the severity of cough between the alfentanil group and the remifentanil group.

CONCLUSION

This study demonstrated that equipotent boluses of alfentanil and remifentanil induced coughing, even though the incidence of cough after alfentanil administration was lower than that after remifentanil administration.

The potential for mu-opioid receptor agonists to be anti-emetic in humans: a review of clinical data

In animal models of vomiting, mu-opioid (MOP, OP(3)) receptors mediate both emesis and anti-emesis. mu-receptors within the blood-brain barrier, mediating anti-emesis, are more rapidly accessible to lipid-soluble mu-opioid receptor agonists such as fentanyl than to morphine, and fentanyl has broad-spectrum anti-emetic effects in a number of species. Whether a similar situation exists in humans is not known. A search was performed for clinical studies comparing the emetic side effects of opioids administered peri-operatively in an attempt to identify differences between morphine and more lipid-soluble mu-receptor-selective agonists such as fentanyl. Overall, the evidence appears to suggest that fentanyl and other phenylpiperidines are associated with less nausea and vomiting than morphine, but not all studies support this, and fentanyl-like drugs are associated with nausea and vomiting per se. Good evidence, however, exists to show that fentanyl and alfentanil do not cause more nausea and vomiting than the ultra fast-acting remifentanil. Because remifentanil is cleared rapidly post-operatively, such trials suggest that the emetic side effects of fentanyl and alfentanil are minimal. The clinical evidence, although limited, is at least consistent with the possibility that central mu-opioid receptors may mediate anti-emesis in humans. It is possible that the role of mu-opioid agonists in anti-emesis may become clearer in the future as a result of the use of peripheral mu-opioid receptor antagonists.

Does propofol and alfentanil-induced sedation cause periodic apnoea in chronic renal failure patients?

AIMS

There is evidence suggesting that the respiratory response to sedation is different in patients with sleep apnoea, which is common in patients with chronic renal failure (CRF). This study examined the respiratory response of sedation with propofol and alfentanil, whose pharmacokinetics are not affected by the renal function, in CRF patients.

METHODS

Chronic renal failure patients who underwent arteriovenous-fistular surgery (CRF group) and patients who underwent chemoport insertion (control group) were enrolled in this study. Sedation was induced by infusing propofol 1.5 micro/ml and alfentanil 0.2 micro/kg/min continuously in both groups. In the desaturation study, the respiratory rate and peripheral oxygen saturation in room air were checked. In the apnoea-hypopnoea study, the patient's sedation (Observer's Assessment of Alertness/Sedation) score, apnoea-hypopnoea index (AHI) was recorded using a portable ventilation effort recorder (microMesam) while applying 5 l/min of oxygen through a facial mask.

RESULTS

The desaturation event was more common (21.5/h vs. 2/h, p = 0.001) in the CRF patients. Apnoea and hypopnoea (AHI: 13.0 vs. 1.6, p = 0.012, per cent of patients with an AHI > 5: 53.3% vs. 7.1%, p = 0.014) occurred more frequently in the CRF patients but the sedation score was not different.

CONCLUSION

Chronic renal failure patients have a higher risk of developing apnoea and hypopnoea during sedation, which highlights the need for careful monitoring and management in these patients.

Randomized clinical trial of propofol with and without alfentanil for deep procedural sedation in the emergency department

OBJECTIVES

The objectives were to compare the efficacy, occurrence of adverse events, and recovery duration of propofol with and without alfentanil for use in procedural sedation in the emergency department (ED).

METHODS

This was a randomized nonblinded prospective trial of adult patients undergoing procedural sedation for painful procedures in the ED. Patients with pain before the procedure were given intravenous (IV) morphine sulfate until their pain was adequately treated at least 20 minutes before starting the procedure. Patients received 1 mg/kg propofol either with or without a supplemental dose of 10 mug/kg alfentanil for deep procedural sedation. Doses, vital signs, nasal end-tidal CO(2) (ETCO(2)), pulse oximetry, and bispectral electroencephalographic (EEG) analysis scores were recorded. Subclinical respiratory depression was defined as a change in ETCO(2) of >10 mmHg, an oxygen saturation of <92% at any time, or an absent ETCO(2) waveform at any time. Clinical events related to respiratory depression were noted during the procedure, including the addition of or increase in the flow rate of supplemental oxygen, the use of a bag-valve mask apparatus, airway repositioning, or stimulation to induce breathing. After the procedure, patients were asked if they experienced pain during the procedure or had recall of the procedure.

RESULTS

A total of 150 patients were enrolled; 146 underwent sedation and were included in the analysis. Seventy-four patients received propofol, and 71 received propofol with alfentanil. No clinically significant complications were noted. Subclinical respiratory depression was seen in 24/74 patients in the propofol group and 30/71 patients in the propofol/alfentanil group (effect size = 9.8%, 95% CI = -5.8% to 25.5%). Clinical signs of respiratory depression included an increase in supplemental oxygen use in 25 of the 74 propofol patients and 31 of the 71 propofol/alfentanil patients (effect size 9.9%, 95% CI = -5.9% to 25.7%), the use of bag-valve mask apparatus in seven patients in the propofol group and 12 in the propofol/alfentanil group (effect size = 5.6%, 95% CI = -3.5% to 18.4%), airway repositioning in 13 propofol patients and 20 propofol/alfentanil patients (effect size = 10.6%, 95% CI = -3.0% to 24.2%), and stimulation to induce breathing in 11 propofol patients and 20 propofol/alfentanil patients (effect size = 13.3%, 95% CI = 0.1% to 26.5%). The total time of the procedure was longer for the alfentanil/propofol group (median = 11 minutes, range = 5-22 minutes) than for the propofol group (median = 9 minutes, range = 1 to 43 minutes; effect size = 1.93 minutes, 95% CI = 0.73 to 2.58, p = 0.02). Pain during the procedure was reported by 10 of the 74 patients in the propofol group and 7 of the 71 patients in the propofol/alfentanil group (effect size = 4.5%, 95% CI = -6.8% to 14.1%). Recall of some part of the procedure was reported by 12 patients in the propofol group and 9 in the propofol/alfentanil group (effect size = 3.5%, 95% CI = -7.9% to 15.0%). All procedures were successfully completed.

CONCLUSIONS

The use of supplemental alfentanil with propofol for procedural sedation did not result in a difference in reported pain or recall immediately after the procedure. There was an increase in the proportion of patients who required stimulation to induce respiration during the procedure in patients who received propofol with supplemental alfentanil. The addition of supplemental opioid to procedural sedation with propofol does not appear beneficial.

Analgesia for retrobulbar block--comparison of remifentanil, alfentanil and fentanyl

BACKGROUND

The injection of retrobulbar block is associated with significant pain and discomfort. Therefore a short-acting IV analgesic before retrobulbar injection has been advocated.

OBJECTIVE

To compare remifentanil, alfentanil and fentanyl in providing analgesia for retrobulbar block injection.

METHODS

69 patients were enrolled randomly into three groups of 23 each to receive either Remifentanil 1 microg/kg, Alfentanil 20 microg/kg or Fentanyl 2 microg/kg as an IV bolus dose prior to retrobulbar injection. Mean arterial pressure (MAP) and heart rate (HR) were recorded and Numerical Pain Score (NPS) were assessed by a blinded observer.

RESULTS

Remifentanil prevented increase in MAP and HR while alfentanil and fentanyl were ineffective in this purpose (p < 0.05). NPS was significantly lower in remifentanil group (p < 0.05).

CONCLUSION

Remifentanil 1 microg/kg prior to retrobulbar injection provide excellent hemodynamic stability and ensure analgesia.

Influence of CYP3A5 genotype on the pharmacokinetics and pharmacodynamics of the cytochrome P4503A probes alfentanil and midazolam

The hepatic and first-pass cytochrome P4503A (CYP3A) probe alfentanil (ALF) is also metabolized in vitro by CYP3A5. Human hepatic microsomal ALF metabolism is higher in livers with at least one CYP3A5*1 allele and higher CYP3A5 protein content, compared with CYP3A5*3 homozygotes with little CYP3A5. The influence of CYP3A5 genotype on ALF pharmacokinetics and pharmacodynamics was studied, and compared to midazolam (MDZ), another CYP3A probe. Healthy volunteers (58 men, 41 women) were genotyped for CYP3A5 *1, *3, *6, and *7 alleles. They received intravenous MDZ then ALF, and oral MDZ and ALF the next day. Plasma MDZ and ALF concentrations were determined by mass spectrometry. Dark-adapted pupil diameters were determined coincident with blood sampling. In CYP3A5(*)3/(*)3 (n=62), (*)1/(*)3 (n=28), and (*)1/(*)1 (n=8) genotypes, systemic clearances of ALF were 4.6+/-1.8, 4.8+/-1.7, and 3.9+/-1.7 ml/kg/min and those of MDZ were 7.8+/-2.3, 7.7+/-2.3, and 6.0+/-1.4 ml/kg/min, respectively (not significant), and apparent oral clearances were 11.8+/-7.2, 13.3+/-6.1, and 12.6+/-8.2 ml/kg/min for ALF and 35.2+/-19.0, 36.4+/-15.7, and 29.4+/-9.3 ml/kg/min for MDZ (not significant). Clearances were not different between African Americans (n=25) and Whites (n=68), or between CYP3A5 genotypes within African Americans. ALF pharmacodynamics was not different between CYP3A5 genotypes. There was consistent concordance between ALF and MDZ, in clearances and extraction ratios. Thus, in a relatively large cohort of healthy subjects with constitutive CYP3A activity, CYP3A5 genotype had no effect on the systemic or apparent oral clearances, or pharmacodynamics, of the CYP3A probes ALF and MDZ, despite affecting their hepatic microsomal metabolism.

Atelectasis in children undergoing either propofol infusion or positive pressure ventilation anesthesia for magnetic resonance imaging

BACKGROUND

Atelectasis because of anesthesia is a recognized problem but may be affected by the anesthetic technique. We compared magnetic resonance images of atelectasis in children undergoing two types of anesthesia.

METHODS

Children requiring anesthesia for magnetic resonance imaging (MRI) had additional lung imaging sequences at the beginning and the end of anesthesia. Children had either i.v. propofol infusion (PI) without an artificial airway (n = 26) or positive pressure ventilation (PPV) via a tracheal tube (n = 20); the technique was chosen for clinical reasons. The extent of atelectasis was scored by two independent radiologists.

RESULTS

The median ages (range) for PI and PPV groups were 45 months (1-77 months) and 18 months (2-74 months), respectively. The proportion of children with atelectasis was different in the first lung scan (42% vs 80%), but in the second scan atelectasis was seen frequently in both groups (82% vs 94%) with a greater extent in the PPV group. The atelectasis score was higher in young children, but all children had normal oxygen requirements and saturations.

CONCLUSIONS

Many factors may influence the development of atelectasis but this study found less extensive atelectasis with PI than PPV. PI allows for sufficient motionlessness, required for high diagnostic image quality in pediatric MRI.

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 Effects of Alfentanil, Fentanyl, and Remifentanil on Hemodynamic and Respiratory Parameters During Stereotactic Brain Biopsy

The aim of this study was to compare the effects of 3 different sedative-analgesic regimens in patients with intracranial mass lesions undergoing stereotactic brain biopsy. A 135 outpatients with American Society of Anesthesiologists I to II were divided into 3 groups: group A (n = 45) received a loading dose of IV alfentanil 7.5 microg/kg followed by infusion rate of 0.25 microg/kg/min; group F (n = 45) received a bolus dose of 1 microg/kg IV fentanyl and repeated as needed; and group R (n = 45) received infusion of 0.05 microg/kg/min remifentanil. Target level of sedation was 3 to 4 of the Ramsay Sedation Scale. Systolic and diastolic blood pressure, heart rate, respiratory rate, peripheric oxygen saturation (SpO2), and end-tidal carbon dioxide were recorded at different stages of the procedures. The patients in group F had significantly lower mean heart rate than those in groups A and R, but this was not in the limits of the bradycardia. The patients in group A had significantly lower mean SpO2 than those in the other groups, but mean SpO2 values did not drop below 94%. There were no significant differences in end-tidal carbon dioxide and respiratory rate values among the groups. Our results suggest that all 3 regimens have relatively similar hemodynamic and respiratory responses. The use of bolus fentanyl technique caused less hemodynamic stability. The continuous infusion technique of remifentanil or alfentanil provided better control on hemodynamic parameters.

Comparison of alfetanil and ketamine in combination with propofol for patient-controlled sedation during fiberoptic bronchoscopy

BACKGROUND

During fiberoptic bronchoscopy, propofol, ketamine, benzodiazepines, and opiates are most commonly used, alone or in combination for sedation. The aim of this study was to compare the clinical efficacy of propofol/ketamine with propofol/alfentanil for patient-controlled sedation (PCS) during fiberoptic bronchoscopy.

METHOD

Patients undergoing fiberoptic bronchoscopy were randomly assigned to receive either propofol/alfentanil (PA group; n = 138) or propofol/ketamine (PK group; n = 138) via a patient-controlled analgesia (PCA) device for sedation and analgesia. Changes in blood pressure, heart rate (HR), and oxygen saturation were monitored. Degree of patient and bronchoscopist satisfaction was evaluated using a 10-cm visual analog scale (VAS) (0 = extremely uncomfortable to 10 = extremely comfortable).

RESULTS

After sedation, systolic arterial pressure (SAP) decreased in the PA group, but SAP was stable in the PK group. Compared with values immediately before starting bronchoscopy, SAP and HR increased during the procedure in both groups (P < 0.05). Patients in the PK group showed more satisfaction [(9.5 (6-10) vs. 9.0 (6-10)), P < 0.05] and amnesia (82% vs. 61%, P < 0.01). Despite these differences, the majority (greater than 90%) of the patients in both groups stated that they were comfortable during the procedure.

CONCLUSION

Our results show that although both techniques proved effective for sedation in patients undergoing fiberoptic bronchoscopy, ketamine is superior to alfentanil when used in combination with propofol because of the high patient satisfaction and amnesia.

Fast-track eligibility, costs and quality of recovery after intravenous anaesthesia with propofol-remifentanil versus balanced anaesthesia with isoflurane-alfentanil

BACKGROUND AND OBJECTIVE

The randomized, patient- and observer-blinded study was performed in 120 patients undergoing ear, nose and throat surgery to test the hypothesis that intravenous anaesthesia with propofol-remifentanil when compared with a balanced anaesthesia technique using isoflurane-alfentanil improves the speed of recovery, minimizes postoperative side-effects and, thus, leads to an improved quality of recovery without increasing total costs.

METHODS

The total costs for each anaesthesia technique were calculated considering drug acquisition costs, personnel costs for the additional time spent in the operating room and the postanaesthesia care unit until fast-tracking eligibility, and the costs to treat the side-effects during and after operation.

RESULTS

The times from the end of surgery to tracheal extubation and the time until leaving the operating room were not different between the two groups. However, more patients receiving intravenous anaesthesia (80 versus 49%) were eligible for fast tracking and thus could bypass the recovery room. This was associated with an average cost saving of 6.00 euros per patient. However, intravenous anaesthesia was associated with higher total costs (89 euros versus 78 euros) mainly because of higher acquisition costs of the anaesthetics (34.60 euros versus 16.50 euros). There was no difference in the quality of recovery as measured by a Quality of Recovery score and patient satisfaction between the two groups.

CONCLUSIONS

The higher acquisition costs of the intravenous anaesthetics propofol and remifentanil cannot be compensated for by improved speed of recovery. This anaesthesia technique is more cost intensive than balanced anaesthesia using isoflurane and alfentanil.

Mood change after anaesthesia with remifentanil or alfentanil

BACKGROUND AND OBJECTIVE

There are anecdotal reports of dysphoria occurring in patients on the first day after anaesthesia with remifentanil. This study was performed to investigate this allegation and to find a possible relationship to postoperative shivering or to nausea and vomiting.

METHODS

Patients undergoing otorhinolaryngeal surgery took part in a prospective, randomized, double-blind study comparing total intravenous anaesthesia with propofol (2 mg kg(-1) bolus injection then 100 microg kg(-1) min(-1)) and remifentanil (1 microg kg(-1) bolus then 0.1-0.5 microg kg(-1) min-1) or alfentanil (30 microg kg(-1) bolus then 0.16-0.83 microg kg((-1) min(-1)). The patients were carefully insulated and actively warmed by convective heating and rectal temperature was monitored continuously. Postoperative shivering was graded on a three-point scale, and the cumulative incidence of nausea and vomiting were registered at 24 h after surgery. Pre- and postoperative mood was measured with the von Zerssen mood scale (Befindlichkeits-Skala) and changes tested for significance. High scores reflect discontent and dysphoria.

RESULTS

The data of 98 patients (49 in each group, ASA I-II, age 42 +/- 13 yr, anaesthesia time 141 +/- 60 min; mean +/- SD; intergroup P values > 0.1) were evaluated. Core temperature did not change perioperatively (before 36.6 +/- 0.2 degrees C; after 36.8 +/- 0.3 degrees C, inter- and intragroup P > 0.1). The incidence of nausea was the same in each group; vomiting occurred with equal frequency (6/49 vs. 7/49). Shivering was significantly more frequent after remifentanil (41% vs. 10%, P < 0.001). The patients' mood remained stable after remifentanil but worsened after alfentanil (von Zerssen score from 9.3 +/- 2.5 to 13.9 +/- 3.6; mean +/- 95% confidence intervals; P < 0.01).

DISCUSSION

Postoperative shivering was more frequent after remifentanil but was unrelated to intraoperative heat loss. Contrary to preliminary informal observations, there was no evidence that remifentanil caused postanaesthetic dysphoria on the day one after surgery.

Piritramide and alfentanil display similar respiratory depressant potency

BACKGROUND

The question whether some opioids exert less respiratory depression than others has not been answered conclusively. We applied pharmacokinetic/pharmacodynamic (PKPD) modeling to obtain an estimate of the C50 for the depression of CO2 elimination as a measure of the respiratory depressant potency of alfentanil and piritramide, two opioids with vastly different pharmacokinetics and apparent respiratory depressant action.

METHODS

Twenty-three patients received either alfentanil (2.3 microg x kg(-1) x min-1, 14 patients, as published previously) or piritramide (17.9 microg x kg(-1) x min(-1), nine patients) until significant respiratory depression occurred. Opioid pharmacokinetics and the arterial PCO2 (PaCO2) were determined from frequent arterial blood samples. An indirect response model accounting for the respiratory stimulation due to increasing PaCO2 was used to describe the PaCO2 data.

RESULTS

The following pharmacodynamic parameters were estimated with NONMEM [population means and interindividual variability (CV)]: k(elCO2) (elimination rate constant of CO2) 0.144 (-) min(-1), F (gain of the CO2 response) 4.0 (fixed according to literature values) (28%), C50 (both drugs) 61.3 microg l-1 (41%), k(eo alfentanil) 0.654 (-) min(-1) and k(eo piritramide) 0.023 (-) min(-1). Assigning separate C50 values for alfentanil and piritramide did not improve the fit compared with a model with the same C50.

CONCLUSION

Since the C50 values did not differ, both drugs are equally potent respiratory depressants. The apparently lower respiratory depressant effect of piritramide when compared with alfentanil is caused by slower equilibration between the plasma and the effect site. Generalizing our results and based on simulations we conclude that slowly equilibrating opioids like piritramide are intrinsically safer with regard to respiratory depression than rapidly equilibrating opioids like alfentanil.

Remifentanil vs alfentanil in the total intravenous anaesthesia for paediatric abdominal surgery

BACKGROUND

Our aim was to investigate whether total intravenous anaesthesia (TIVA) with remifentanil and alfentanil would ensure appropriate analgesia and recovery conditions in anaesthesia for children undergoing abdominal surgery.

METHODS

Sixty children, scheduled for abdominal operations were randomized to receive, in a double-blind manner, either remifentanil (loading dose 1 microg x kg(-1); maintenance infusion, 0.25 microg x kg(-1) min(-1)) or alfentanil (loading dose 50 microg x kg(-1); maintenance infusion, 1 microg x kg(-1) min(-1)) as the analgesic component of TIVA. They were combined with propofol (loading dose, 2 mg x kg(-1); step 1 maintenance infusion, 10 mg x kg(-1) h(-1); step 2 maintenance infusion, 8 mg x kg(-1) h(-1); step 3 maintenance infusion, 6 mg x kg(-1) h(-1)) neuromuscular blockade was with mivacurium. Dose changes of the drugs, the times from cessation of anaesthesia to extubation, verbal responses, recovery of ventilation, orientation, and qualification for discharge from the postanaesthetic care unit (PACU) were recorded.

RESULTS

Demographics, duration of surgery and anaesthesia were similar between the two groups. Times to extubation and stay in the PACU were significantly shorter in the remifentanil group compared with the alfentanil group. Quality of emergence (QE) from anaesthesia scale scores were higher in the remifentanil group compared with the alfentanil group.

CONCLUSIONS

Remifentanil provides a more rapid recovery and adequate postoperative analgesia after TIVA for paediatric abdominal surgery, compared with alfentanil.

Effects of dopamine antagonists on alfentanil–induced locomotor activity in horses

OBJECTIVE

To determine whether specific dopamine receptor antagonists block alfentanil-induced locomotor stimulation in horses.

STUDY DESIGN

Randomized, prospective, crossover experiment.

ANIMALS

Eight adult horses (462-604 kg).

METHODS

Doses of dopamine-1 (D1) (NNC 01-0756) and dopamine-2 (D2) antagonists (eticlopride) were selected in a pilot study prior to a three part, blinded, cross-over study. In part 1, horses received 7.5 micro g kg-1 eticlopride, 5 micro g kg-1 NNC 01-0756 or an equal volume of saline. In part 2, they received both antagonists and in part 3, acepromazine at 0.05 mg kg-1. Locomotor activity was assessed by counting the steps taken by a marked forefoot per 2 minutes. The D antagonist was injected IV after a 20-minute control period. The horses were observed for 10 minutes before alfentanil (20 micro g kg-1) was injected IV. Locomotor activity was then monitored for 60 minutes. Statistical analysis was performed on step counts following alfentanil normalised by subtracting the mean control step count from each value recorded after alfentanil. Data were analysed using Friedman tests and Tukey-Kramer comparisons.

RESULTS

Alfentanil increased locomotor activity for 10 minutes. NNC 01-0756 tended to reduce locomotor activity between 0 and 10 minutes (p = 0.261), but neither D antagonist suppressed it significantly. The combination of D antagonists induced more step counts than saline or acepromazine (p = 0.0265) in the 20-40-minute period and more than saline, acepromazine or eticlopride between 40 and 60 minutes (p = 0.0003).

CONCLUSIONS

Neither D1 nor D2 antagonists inhibited alfentanil-induced locomotor activity. Both drugs appeared to cause locomotor stimulation of their own.

CLINICAL RELEVANCE

D1 and D2 antagonism did not reduce opioid-induced excitement in horses and is not suitable for reducing the incidence of this unwanted side-effect of opioids.