ED50 and ED95 of Propofol Combined with Different Doses of Intravenous Lidocaine for First-Trimester Uterine Aspiration: A Prospective Dose-Finding Study Using Up-and-Down Sequential Allocation Method

Effect of Dexmedetomidine on the ED50 and ED95 of Sufentanil in Patient-Controlled Intravenous Analgesia After Cesarean Section: A Randomized, Controlled, Double-Blind Trial

Purpose

To determine the effect of dexmedetomidine on the ED50 and ED95 of sufentanil in patient-controlled intravenous analgesia (PCIA) after cesarean section.

Patients and Methods

Parturients who underwent elective cesarean section (n = 80) were randomly assigned to either the sufentanil group (S group) or the dexmedetomidine-sufentanil combination group (DS group). Patients in the S group received a combination of sufentanil, 5 mg of tropisetron, and saline, whereas patients in the DS group were administered 1.5µg/kg of dexmedetomidine in addition to sufentanil, 5 mg of tropisetron, and saline. The ED50 and ED95 of sufentanil were determined by Dixon sequential method. We used probit regression to calculate the ED50, ED95, and 95% confidence intervals for sufentanil in each group.

Results

The ED50 and ED95 for sufentanil in the S group were 1.634 (95% CI: 1.476-1.810)µg/kg and 2.035 (95% CI: 1.841-3.312)µg/kg, respectively. The ED50 and ED95 for sufentanil in the DS group were 1.275 (95% CI: 1.187-1.353)µg/kg and 1.503 (95% CI: 1.406-1.824)µg/kg. The VAS scores with rest at t5 and with movement at t4- t5 were lower in the DS group (P< 0.05). The t2-t5 Ramsay scores in the DS group were higher than those in the S group (P< 0.05). The doses of sufentanil and tramadol were markedly reduced in the DS group, while the onset of first lactation occurred significantly earlier in the DS group (P< 0.05). Compared with the S group, the DS group had a lower incidence of nausea, vomiting, and skin itching (P< 0.05), and lower frequency of patient-controlled analgesia (PCA) episodes (P< 0.05), and better postoperative pain satisfaction (P< 0.05).

Conclusion

The 1.5µg/kg dexmedetomidine can significantly decrease the ED50 and ED95 of sufentanil in patient-controlled intravenous analgesia after cesarean section, provide good postoperative analgesia and sedation, and promote the earlier occurrence of first lactation.

Effects of mild cognitive impairment and sleep disorders on the minimum alveolar concentration value of sevoflurane

OBJECTIVES

To explore the effect of mild cognitive impairment (MCI) and MCI with sleep disorders on the potency of sevoflurane anesthesia in the elderly.

DESIGN

Prospective study methods. Dixon up-and-down methods.

SETTING

Comprehensive public tertiary hospital, Cangzhou City, Hebei Province, China.

PARTICIPANTS

70 elderly patients scheduled for elective unilateral breast cancer surgery and finally analyzed 58 patients, including 30 patients with MCI (group M) and 28 patients with MCI with sleep disorders (group MS).

OUTCOME MEASURES

The required minimum alveolar concentration (MAC) value of sevoflurane in the two groups was determined using the Dixon up-and-down method. The MAC value of sevoflurane and its 95% confidence interval (CI) were calculated using the logistic regression method. Serum melanin-concentrating hormone concentrations were determined by Elisa kits.

RESULTS

The MAC value of sevoflurane in group M was 1.43 (95% CI 1.05-1.61%), and the MAC value of sevoflurane in group MS was 1.93 (95% CI 1.78-2.08%), There were notable differences between the two groups (P < 0.0001). The level of melanin-concentrating hormone (MCH) in the MS group was significantly lower than that in the M group (21.52 ± 3.82 vs. 37.17 ± 3.66 pg/ml, P < 0.0001). There was a significant negative correlation between MCH levels and the probability of body movement during skin incision (OR = 0.844, 95% CI: 0.715-0.996, P = 0.045).

CONCLUSIONS

Patients with MCI with sleep disorders required higher doses of sevoflurane than those with MCI alone. Changes in anesthetic requirements may be related to changes in MCH levels.

Effect of Lidocaine on Ciprofol Dosage and Efficacy in Patients Who Underwent Gastroscopy Sedation

BACKGROUND Intravenous ciprofol is a short-acting sedative with minimal respiratory and circulatory suppression and limited analgesia. Intravenous lidocaine provides analgesia during surgical procedures. This study included 70 patients who underwent gastroscopy with analgesia and aimed to evaluate the effects of intravenous lidocaine on the dose of ciprofol required to produce 50% of the maximal effect (ED50). MATERIAL AND METHODS Seventy patients scheduled for elective painless gastroscopy were randomly assigned into 2 groups: group L (n=35, received ciprofol and 1.5 mg/kg lidocaine) and group S (n=35, received ciprofol and normal saline). The primary outcomes measured were the ED50 and the 95% effective dose (ED95) of ciprofol, determined using the modified up-down sequential method and Probit analysis. Secondary outcomes included induction, operation, and recovery times; monitoring of vital signs such as mean arterial pressure, heart rate, and oxygen saturation; and evaluation of postoperative adverse reactions, including sore throat, nausea, vomiting, abdominal pain, and satisfaction scores from endoscopists and anesthesiologists. RESULTS The ED50 of ciprofol in group L was 0.315 mg/kg (95% CI, 0.291-0.342 mg/kg), which was significantly lower than that in group S, 0.42 mg/kg (95% CI, 0.371-0.491 mg/kg). Additionally, group L exhibited shorter induction and recovery times, a lower incidence of postoperative sore throat, and a temporary drop in blood pressure following induction. CONCLUSIONS Intravenous lidocaine during painless gastroscopy reduces the required ciprofol dose, shortens induction and recovery times, and lowers the incidence of postoperative complications, such as sore throat. These findings support its effective role in improving sedation quality and patient outcomes during gastroscopy.

Determination of the effective dose of remimazolam combined with sufentanil for inhibiting body movement during surgical abortion: An up-and-down sequential allocation trial

BACKGROUND

Remimazolam, a recently developed anesthetic characterized by its rapid and ultra-short-acting properties, exhibits pharmacological attributes that make it potentially suitable for painless surgical abortion procedures. The objective of this study was to determine the effective dose of remimazolam when administered in combination with sufentanil, with the intention of inhibiting body movement during surgical abortion. Additionally, a secondary objective was to assess the recovery profile from general anesthesia.

METHODS

The study enrolled a total of 25 healthy women aged 20 to 40, with a body mass index between 18 and 28 kg/m2, in their first trimester of pregnancy (up to 12 weeks), and American Society of Anesthesiologists status I and II. Anesthesia induction was initiated by administering sufentanil at a dose of 0.1 μg/kg. The modified Dixon up-and-down method was employed to determine the induction dose of remimazolam for each patient.

RESULTS

The 50% and 95% effective dose of remimazolam for inhibitory effects of body movement was estimated using centered isotonic regression to be 0.145 mg/kg (95% CI: 0.115, 0.207), and 0.242 mg/kg (95% CI: 0.232, 0.620), respectively. Five out of 25 (20%) experienced hiccups, with 1 patient having persistent hiccups until the end of the surgery. The mean time to first eye-opening was 51.4 ± 20.5 seconds, and the time to obey verbal command was 54.5 ± 20.6 seconds. Upon arrival at the postanesthesia care unit, 95.7% of the patients achieved a Modified Aldrete score ≥ 9.

CONCLUSIONS

The 50% and 95% effective dose of remimazolam for inhibiting body movement during surgical abortion when used in combination with 0.1 μg/kg of sufentanil were 0.145 mg/kg and 0.242 mg/kg, respectively.

Effectiveness and safety of remimazolam combined with alfentanil in hysteroscopic examination: A prospective, randomized, single-blind trial

BACKGROUND

Remimazolam is a novel, ultrashort-acting benzodiazepine. This study aimed to compare the efficacy and safety of remimazolam and propofol for hysteroscopic examination, to determine the optimal dose of remimazolam combined with alfentanil for painless hysteroscopy, and to calculate its median effective dose (ED50).

METHODS

Step 1: A total of 208 patients undergoing hysteroscopic examination were prospectively included in this study. Patients were randomized into 4 groups: 0.2 mg/kg remimazolam (group A), 0.25 mg/kg remimazolam besylate (group B), 0.3 mg/kg remimazolam (group C), and 2 mg/kg propofol (group D), with 52 patients in each group. One minute after losing consciousness, patients received an intravenous injection of alfentanil at 5 µg/kg, followed by a continuous infusion of alfentanil at 0.5 µg/kg/min. If patients showed frowning, movement, or MOAA/S > 1, sedatives were added: 0.05 mg/kg/dose of remimazolam for groups A, B, and C, and 0.5 mg/kg/dose of propofol for group D. Step 2: Dixon's up-and-down method was used to calculate the ED50 of remimazolam combined with alfentanil during hysteroscopic examination.

MAIN RESULTS

The sedation success rates of the remimazolam groups were 88.46%, 94.23%, and 98.08%, respectively, compared to 96.15% in the propofol group, with no significant difference (P = .175). MAP in groups A and B was higher than in group D (P < .05), and significantly higher in group C than in group D (P = .0016). SpO2 values in groups A, B, and C were higher than in group D at T2 to T3 (P < .001). HR in groups A, B, and C was significantly higher than in group D (P < .001). The ED50 of remimazolam combined with alfentanil in hysteroscopy was 0.244 mg/kg, 95%CI (0.195-0.22) and ED95 was 0.282 mg/kg, 95%CI (0.261-1.619).

CONCLUSION

In hysteroscopy, the sedative effect of remimazolam is like that of propofol, with 0.25 mg/kg remimazolam showing better safety and efficacy, and less impact on the respiratory and circulatory systems. Additionally, under the influence of alfentanil, the ED50 of remimazolam in hysteroscopy is 0.244 mg/kg, with no severe adverse reactions observed.

Median Effective Dose of Ciprofol Combined With Sufentanil for Inhibiting the Upper Gastrointestinal Endoscopic Placement Reaction in Elderly Patients

Objective

Ciprofol is a new sedative anesthetic drug that can be used for gastrointestinal endoscopy and induction of general anesthesia, but the appropriate dosage for use in elderly patients has not been determined. Sufentanil is a commonly used opioid in clinical practice, and this study was designed to induce anesthesia in elderly patients using sufentanil in combination with ciprofol. However, the optimal dosage of ciprofol when it is co-administered with sufentanil has not yet been established. This study was designed to find the median effective dose (ED50) and 95% confidence interval (95% CI) of ciprofol for intravenous anesthesia when combined with sufentanil.

Methods

We studied 57 patients who were scheduled to undergo a diagnostic upper gastrointestinal endoscopy. According to age, it was divided into two groups: 65∼74 years old (group A) and over 75 years old (group B). Using the modified Dixon sequence test method, intravenous bolus of 0.1 μg/kg sufentanil was given 3 min before ciprofol is administered, the initial dose of ciprofol was 0.4 mg/kg, the upper gastrointestinal endoscopy was placed after reaching the depth of sedation, and vital signs and adverse events were recorded at each perioperative time point (T0-T7).

Results

In the group A, when combined with 0.1 μg/kg sufentanil, the ED50 of ciprofol to inhibiting responses to insertion of upper gastrointestinal endoscopy was 0.23 mg/kg, and the 95% CI was 0.09∼0.30 mg/kg; in the group B, the ED50 was 0.18 mg/kg, and the 95% CI was 0.13∼0.22 mg/kg.

Conclusion

The ED50 of ciprofol in combination with sufentanil (0.1 μg/kg) for upper gastrointestinal endoscopy in elderly patients: 0.23 mg/kg in group A and 0.18 mg/kg in group B.

Intravenous Lidocaine Decreased the Median Effective Concentration of Sufentanil for Tracheal Intubation in Obese Patients

Purpose

Sufentanil has been widely used to inhibit the hemodynamic responses caused by tracheal intubation. Using intravenous lidocaine may reduce the dose of sufentanil and better maintain the hemodynamics. This study aimed to determine the effects of intravenous lidocaine on the median effective concentration (EC50) of sufentanil for endotracheal intubation in obese patients.

Patients and Methods

This is a randomized, double-blind, up-and-down sequential allocation study. Fifty obese patients undergoing bariatric surgery were randomly allocated in a 1:1 ratio into the lidocaine group and the saline group. Anesthesia was induced using a target-controlled infusion of propofol and sufentanil. The effect-site concentration (Ce) of propofol was 3.5 μg/mL. The Ce of sufentanil for the first patient was 0.4 ng/mL, and the sufentanil dose for the next patient was determined according to the responses of the previous patient, using Dixon's up-and-down sequential method with an interval of 0.05 ng/mL. When the target concentration of propofol and sufentanil was reached, lidocaine 1.5 mg/kg or the same volume of normal saline was infused over 3 min. Tracheal intubation was performed 3 min after the end of the lidocaine or normal saline infusion. Probit regression was used to calculate the EC50 and 95% confidence interval (CI) of sufentanil.

Results

Thirty-eight patients completed this study. The EC50 of sufentanil was 0.36 ng/mL (95% CI: 0.31-0.41 ng/mL) in the lidocaine group, which was significantly lower than 0.50 ng/mL (95% CI: 0.43-0.62 ng/mL) in the saline group. In addition, compared with saline group, the dosage of sufentanil in lidocaine group decreased significantly during the test. The hemodynamics of the two groups were stable during the study period.

Conclusion

Intravenous lidocaine 1.5 mg/kg decreased the EC50 of sufentanil required for tracheal intubation in obese patients undergoing bariatric surgery.