The Use of Remifentanil as the Primary Agent for Analgesia in Parturients

Remifentanil at a Relatively Elevated Dose in Active Phase is Safe and More Suitable Than Fixed Lower Dose for Intravenous Labor Analgesia

Background

Intravenous labor analgesia is recommended as an alternative for parturients who have contraindications to epidural analgesia. There are several opioid analgesics and different administering regimens used in the clinic. This study aimed to compare the effectiveness and safety of two intravenous remifentanil dosage regimens in the first labor stage.

Patients and Methods

One hundred and fifteen parturients with a contraindication to epidural analgesia but were willing to receive systemic labor analgesia were randomized into group A received a fixed dose of remifentanil throughout the first stage of labor, and group B received an elevated dose of remifentanil during the active phase of the first stage both by patient-controlled analgesia (PCA). Maternal numerical rating scale (NRS) pain score and oxygen desaturation, sedation efficacy, satisfaction, as well as maternal and fetal adverse reactions were recorded and compared.

Results

The mean NRS pain scores before analgesia and in the latent phase showed no statistically significant difference between the two groups (P > 0.05). However, during the active phase, group B demonstrated significantly lower mean NRS pain scores and lowest pain score compared to group A (P < 0.05). Furthermore, group B exhibited higher overall sedation scores and satisfaction scores in comparison to group A (P < 0.05). The incidence of adverse reactions between the two groups was similar (P > 0.05).

Conclusion

Relatively elevated intravenous dosage of remifentanil with PCA during the active phase in the first stage of labor is safe and more effective than a fixed-dosage regimen for labor analgesia.

Trial Registration

This study was registered with ChiCTR on 24/08/2021 with trial identification number: ChiCTR2100050247. First participant was recruited on 31/08/2021. The last patient was recruited on 12/08/2022.

The effects of intravenous remifentanil on umbilical artery serum-derived exosomes in parturients undergoing epidural anesthesia: a randomized trail

BACKGROUND

Umbilical artery serum-derived exosomes (UEs) serve as messengers for maternal-fetal information exchange and cellular regulation. Intravenous remifentanil could be considered as an effective adjunct to epidural anesthesia in providing a favorable analgesia effect for cesarean section (C-section), but its effects on UEs are currently unknown.

METHODS

From 01/12/2021 to 30/06/2022, eligible parturients scheduled for repeated C-section at the First Affiliated Hospital of Wenzhou Medical University were randomized to receive either an intravenous bolus (0.15 μg/kg) followed by a continuous infusion (0.075 μg/kg/min) of remifentanil or normal saline throughout the procedure. The primary outcome was the number of UEs. Secondary outcomes included the size and protein amount of UEs, the vital signs, visceral pain score, sedation score, maternal satisfaction score, Apgar score, the incidence of neonatal asphyxia, umbilical arterial pH, and the presence of complications.

RESULTS

Nanoparticle tracking analysis indicated similar size of UEs between the two groups, but the number and protein amount of UEs were increased in the remifentanil group  compared to the control group (P < 0.05). In parturients receiving remifentanil, visceral pain scores were decreased, which was accompanied by the increased scores of maternal satisfaction with the anesthetic method (P < 0.05). Other maternal and neonatal outcomes were comparable between the two groups (P > 0.05).

CONCLUSION

The intravenous administration of remifentanil increased the number of UEs in parturients undergoing repeated C-section under epidural anesthesia, with improved birth experience and minimal neonatal complications.

Remifentanil reduces glutamate toxicity in rat olfactory bulb neurons in culture

Background

Opioids are widely used as an analgesic drug in the surgical setting. Remifentanil is an ultra-short acting opioid with selective affinity to the mu (μ) receptor, and also exhibits GABA agonist effects. The aim of this study was study of the neurotoxic or neuroprotective effect of different doses of remifentanil in glutamate-induced toxicity in olfactory neuron cell culture.

Materials and methods

Olfactory neurons were obtained from newborn Sprague Dawley rat pups. Glutamate 10^-5 mM was added to all culture dishes, except for the negative control group. Remifentanil was added at three different doses for 24 hours, after which evaluation was performed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), Total Antioxidant Capacity (TAC), Total Oxidant Status (TOS), and Annexin V.

Results

The highest and lowest viability values were obtained from the low and high remifentanil doses at approximately 91% and 75%, respectively. TAC and TOS were correlated with the MTT results. TAC, TOS and MTT most closely approximated to the sham group values in the remifentanil 0.02 mM group.

Conclusions

Our results suggest that remifentanil has the potential to reduce glutamate toxicity and to increase cell viability in cultured neuron from the rat olfactory bulb.

Pre- and during- labour predictors of dystocia in active phase of labour: a case-control study

Background

Labour dystocia (LD) is associated with maternal and foeto-neonatal complications and increased rate of caesarean section. There are scant studies on predictive factors of labour dystocia in Iran, as well as in other countries. Therefore, this study aimed to identify the predictive factors of LD using an integrated and collaborative pre- and during- labour factors to help formulate more effective intervention strategies for prevention and management of LD.

Methods

In this case-control study, 350 women with and 350 women without LD, matched individually in terms of parity and hospital, were compared. The participants were in active labor, had singleton pregnancy, live foetus with a cephalic presentation, gestational age of 37^+ 0–41^+ 6 weeks, and were hospitalized for vaginal birth in two teaching hospitals in Tabriz, Iran. Data related to the socio-demographic characteristics, anxiety status (using the Spielberger State Anxiety Inventory), and woman dehydration were collected at cervical dilatation between 4 and 6 cm (before dystocia detection) and the other data at different phases of labour, and after birth (before discharge). The multivariate logistic regression was used to determine the predictors.

Results

The predictors of LD were severe [OR 58.0 (95% CI 26.9 to 125.1)] and moderate [8.6 (4.2 to 17.4)] anxiety, woman dehydration > 3 h [18.67 (4.0 to 87.3)] and ≤ 3 h [2.8 (1.7 to 4.8], insufficient support by the medical staff in the delivery room [5.8 (1.9 to 17.9)], remifentanil administration [3.1 (1.5 to 6.2)], labour induction [4.2 (2.5 to 7.2], low income [2.0 (1.2 to 3.3)], woman’s height < 160 cm [2.0 (1.1 to 3.3)], and woman age of 16–20 y [0.3 (0.2 to 0.6)]. The proportion of the variance explained by all these factors was 74%.

Conclusion

The controllable predictors, such as woman anxiety and dehydration, and insufficient support from medical staff during labour were strongly associated with the risk of LD. Therefore, it seems that responding to woman physical, psychological, and supportive needs during labour can play a significant role in LD prevention and control.

Ethical code

IR.TBZMED.REC.1397.624.