Effects of age on effect-site concentration of remifentanil for suppressing anesthetic emergence cough in male patients undergoing laparoscopic cholecystectomy

Predicting the optimal concentration of remifentanil for skull pin fixation with hemodynamic and analgesia nociception index monitoring

Inadequate antinociception during skull pin fixation may cause hemodynamic instability in intracranial surgery. The optimal concentration of remifentanil to provide adequate antinociception and stable hemodynamics during skull pin fixation under analgesia nociception index monitoring is unknown. This study is to assess the 90% effective concentration of remifentanil for skull pin fixation under hemodynamic and analgesia nociception index monitoring. Twenty-six patients were enrolled for intracranial surgery, anesthesia was induced and maintained under total intravenous anesthesia using target-controlled infusion for remifentanil and propofol under analgesia nociception index and bispectral index monitoring. Skull pin fixation was performed at different effect-site concentrations of remifentanil required for Dixon's up-and-down method with a step size of 0.5 ng/ml under bispectral index 40-60. Inadequate antinociception is defined when either ANI < 30 or > 20% in hemodynamic changes from baseline (e.g. heart rate > 100 beats/min, or blood pressure > 180/100 mmHg) and the effect-site concentration of remifentanil is considered as failure. It is considered success as ANI > 30 and < 20% hemodynamic changes from baseline simultaneously. Seven pairs of failure/success were used for probit analysis. The 90% effective concentration of remifentanil for skull pin fixation with adequate antinociception and hemodynamic stability was 4.7 ng/ml.

Remifentanil requirement for i-gel insertion is reduced in male patients with Parkinson's disease undergoing deep brain stimulator implantation: an up-and-down sequential allocation trial

Background

Laryngeal mask airways have been widely used in clinical practice. The aim of this study was to investigate whether the remifentanil requirement for facilitation of i-gel insertion in Parkinson’s disease (PD) patients undergoing deep brain stimulation (DBS) surgery was different from that in non-PD (NPD) patients undergoing intracranial surgery.

Study design

An up-and-down sequential allocation trial.

Methods

Male patients aged between 40 and 64 years old were enrolled. The first patient in each group (PD and NPD) group received an effect-site concentration (Ce) of remifentanil (Minto pharmacokinetic model) of 4.0 ng.ml⁻¹ during a target-controlled infusion (TCI) of 3.5 μg.ml⁻¹ propofol (Marsh pharmacokinetic model). The next dose of remifentanil was determined by the response of the previous patient. The Ce of remifentanil required for i-gel insertion in 50% of patients (EC₅₀) was estimated by the modified Dixon’s up-and-down method and by probit analysis.

Results

The PD group included 24 patients and the NPD group included 23. The EC₅₀ of remifentanil for i-gel insertion during a TCI of 3.5 μg.ml⁻¹ propofol estimated by the modified Dixon’s up-and-down method in PD patients (2.38 ± 0.65 ng.ml⁻¹) was significantly lower than in NPD patients (3.21 ± 0.49 ng.ml⁻¹) (P = 0.03). From the probit analysis, the EC₅₀ and EC₉₅ (effective Ce in 95% of patients) of remifentanil were 1.95 (95% CI 1.52–2.36) ng.ml⁻¹ and 3.12 (95% CI 2.53–5.84) ng.ml⁻¹ in PD patients and 2.85 (95% CI 2.26–3.41) ng.ml⁻¹ and 4.57 (95% CI 3.72–8.54) ng.ml⁻¹ in NPD patients, respectively.

Conclusions

The remifentanil requirement for successful i-gel insertion is reduced in male PD patients undergoing DBS implantation during propofol TCI induction. Clinicians should closely monitor the remifentanil requirement in patients with PD.

Trial registration

Registered at http://www.chictr.org.cn (ChiCTR1900021760).

The Impact of Age on Propofol Requirement for Inducing Loss of Consciousness in Elderly Surgical Patients

It is generally accepted that geriatric patients are more sensitive to propofol than adults; thus, a dose-adjusted propofol is recommended for these patients during the induction of anesthesia. However, for patients aged 75 years and over, established guidelines for propofol induction doses do not provide dose references. To this end, we observed 80 surgical patients (female 39, male 41, American Society of Anesthesiologists physical status score I ∼ II) to access the appropriate dose of propofol for inducing loss of consciousness (LOC). Accordingly, patients were subdivided into group A (20 patients, 45–64 years), group B (20 patients, 65–74 years), group C (20 patients, 75–84 years), and group D (20 patients, ≥ 85 years). All patients received propofol (at a rate of 0.3 mg/kg/min) alone for inducing LOC, which was defined by loss of both eyelash reflex and verbal response. Compared with group A, the propofol requirement for LOC in Group B, C and D decreased by 14.8, 25.2 and 38.5%, respectively. Bivariate linear correlation analysis showed that propofol requirement was negatively correlated with age. After adjusting for potential confounders, age was still an independent factor affecting propofol requirement. In conclusion, the propofol requirement for inducing LOC decreased significantly in elderly patients. We demonstrated that age was an independent factor impacting propofol requirement for LOC during the induction of general anesthesia, implying that the propofol dose for anesthesia induction should be further reduced in elderly surgical patients, especially those aged 75 years and over.

The Effect of Ramosetron on Remifentanil in Preventing Emergence Cough from Sevoflurane Anesthesia in Female Patients

BACKGROUND

Remifentanil reduces cough during extubation. Ramosetron, a 5-HT3 receptor antagonist, is a potent antiemetic. Regarding the antitussive property of 5-HT receptor agonists, ramosetron can mediate the cough reflex, as increasing the remifentanil requirement. The aim of this study was to evaluate the effect of ramosetron on the optimal effect-site concentration (Ce) of remifentanil for preventing emergence cough from sevoflurane anesthesia in female patients.

METHODS

Forty-seven female patients undergoing laparoscopic cholecystectomy randomly received either ramosetron 0.3 mg (n = 23) or the same volume of normal saline (n = 24) intravenously at the end of surgery. The remifentanil Ce using target controlled infusion in 50% of patients (EC50) and 95% of patients (EC95) were assessed using Dixon's up-and-down or isotonic regression method with a boot¬strapping approach.

RESULTS

Using Dixon's up-and-down method, the EC50 of remifentanil in the control group (1.33 ± 0.38 ng/mL) was comparable to that of ramosetron group (1.50 ± 0.69 ng/mL) (P = 0.615). Using isotonic regression analysis, the EC50 (83% confidence interval) did not differ between the two groups (1.17 [0.86-1.43] ng/mL and 1.13 [0.68-1.56] ng/mL in control and ramosetron groups). However, the EC95 (95% confidence interval) was significantly lower in the control group than in the ramosetron group (1.90 [1.45-1.96] ng/mL and 2.92 [2.35-2.97] ng/mL).

CONCLUSION

Remifentanil Ce for preventing emergence cough was higher in the ramosetron group than the control group. It may indicate the lowering effect of ramosetron on antitussive activity of remifentanil.

Propofol combined with remifentanil reduces the adverse reactions of patients undergoing laparoscopic cholecystectomies

OBJECTIVE

To explore the effectiveness of using isoflurane and propofol combined with remifentanil in laparoscopic cholecystectomies (LC).

METHODS

A total of 118 patients undergoing LC in our hospital from April 2018 to January 2019 were recruited as the study cohort. 56 of the patients were anesthetized with isoflurane combined with remifentanil during their operations (the IR group), and the other 62 patients were anesthetized with propofol combined with remifentanil during their operations (the PR group). The effects of the two anesthesia methods on the hemodynamics and stress responses were compared, and the postoperative recoveries, adverse reactions, analgesia, and cognitive functions were recorded.

RESULTS

Compared with the IR group, the average arterial pressure, heart rate, norepinephrine, and cortisol decreased in the PR group. Compared with the IR group, the total postoperative adverse reaction rate was lower in the PR group. Compared with the IR group, the spontaneous respiration recovery times, the times to opening eyes, and the extubation times were significantly shortened in the PR group. There was no significant difference in the postoperative pain levels between the two groups. Compared with the IR group, the postoperative cognitive function assessment was better in the PR group.

CONCLUSION

Compared with isoflurane combined with remifentanil, propofol combined with remifentanil has a smaller impact on the hemodynamics and cognitive functions of patients undergoing LC, and it causes a more significant reduction in the stress response. In addition, its postoperative adverse reactions are lower, so it is worthy of promoting in clinical practice.

Influence of (ATP)-Binding Cassette Transporter Subfamily B Member 1 (ABCB1) Gene Polymorphism on the Efficacy of Remifentanil

Background

The aim of this study was to investigate the influence of adenosine triphosphate (ATP)-binding cassette transporter subfamily B member 1 (ABCB1) gene polymorphism on the efficacy of Remifentanil.

Material/Methods

A total of 276 patients undergoing elective surgeries were included to collect general clinical information and detect the polymorphism of ABCB1 rs1045642 using the TaqMan-MGB probe, and they were divided into 3 groups – a genotype AA group, a genotype AG group, and a genotype GG group – based on different genotypes of ABCB1 rs1045642.

Results

The comparisons showed that there were no differences in sex, age, body mass index (BMI), smoking, drinking status, or ASA class among the 3 groups (P>0.05). The genotype GG group had higher consumption of Remifentanil than the genotype AA group (P<0.05), but the genotype AG group was not different from the genotype AA and GG groups (P>0.05). Comparison of the surgery duration revealed no difference among the 3 groups (P>0.05). The analepsia time, autonomous respiratory recovery time, and orientation recovery time in the genotype GG group were longer than in the genotype AA group (P<0.05), but the genotype AG group was not different from the genotype AA and GG groups (P>0.05). There were no differences in adverse reactions among the 3 groups (P>0.05).

Conclusions

ABCB1 gene polymorphism can affect the clinical efficacy of Remifentanil.