Répercussions maternelles et néonatales de l'anesthésie générale par rémifentanil pour césarienne programmée

Fetal, Preterm, and Term Neonate Exposure to Remifentanil: A Systematic Review of Efficacy and Safety

BACKGROUND

Owing to its pharmacodynamic properties, especially the rapid onset and short duration of its action, the use of remifentanil in obstetric anesthesia, as well as in neonatology, might be increasingly used.

OBJECTIVE

We conducted a systematic review to assess the efficacy and safety of remifentanil in preterm and term neonates. Outcomes of interest were neonatal adaptation after fetal exposure; neonatal pain, distress, and discomfort control during invasive procedures; and the occurrence of hemodynamic effects or respiratory depression induced by remifentanil infusion.

METHODS

Given the different contexts of use, we have organized this work into three parts: (A) use of remifentanil for labor or cesarean section, with exposure of the fetus before birth, (B) brief use for neonatal procedural analgesia, and (C) prolonged use for sedation/analgesia of neonates. The bibliographic search was conducted based on keywords using electronic medical databases (DATABASE, Cochrane Library, PubMed, and EMBASE) from 1 January 2000 until 31 December 2022.

RESULTS

Twenty-two articles were included (10 in part A, 5 in part B and 7 in part C). Prospective, controlled, randomized, blinded, and intention-to-treat trials were retained. Neonates were well adapted after exposure to remifentanil in the fetal period. Pain, stress, and discomfort were controlled during a brief or prolonged invasive procedure when remifentanil was used for sedation/analgesia. The physiological parameters were stable and the procedures were straightforward. Chest wall rigidity appeared to be a common side effect, but this can be managed by slow and continuous infusion and by using the minimum effective dose.

CONCLUSIONS

Remifentanil appears to be effective and safe in the short term in preterm and full-term neonates. However, its safety is compromised by the risk of chest wall rigidity. It should be used in appropriate neonatal units and in the presence of physicians able to monitor its side effects. Long-term outcomes have not been evaluated, to our knowledge.

Effect on Neonatal Outcome of Pharmacological Interventions for Attenuation of the Maternal Haemodynamic Response to Tracheal Intubation: A Systematic Review

The primary aim of this systematic review was to assess the effect on neonatal outcome of pharmacological interventions used for attenuation of the haemodynamic response to tracheal intubation in patients undergoing caesarean Section under general anaesthesia. A systematic search of randomised controlled trials from 1990 to 2015 was conducted. The primary outcome measure was the Apgar score at five minutes and secondary outcomes were umbilical arterial blood gas parameters and neurological adaptive capacity scores. Twenty-seven randomised controlled trials (1,689 patients) were included in the qualitative synthesis. Only five studies using opioids (383 patients) and five studies using non-opioid analgesics (358 patients) were subjected to meta-analysis. The Apgar score at five minutes was significantly lower in neonates of opioid-treated mothers (mean difference: −0.29, 95% confidence interval −0.56 to −0.02, P-value=0.03) compared to mothers in the control group; the umbilical arterial pH was lower and there was a higher requirement for tactile stimulation in neonates. No difference was seen in Apgar scores of neonates of mothers administered non-opioid analgesics compared to placebo. No difference was observed in other parameters between opioid- or non-opioid-treated mothers. This review suggests that opioid interventions for attenuation of the haemodynamic response to tracheal intubation in pregnant patients under general anaesthesia affect neonatal Apgar scores at five minutes in neonates but the difference did not appear to be clinically meaningful. We were unable to demonstrate any difference in safety.

Comparison of the effects of low doses of dexmedetomidine and remifentanil on the maternal hemodynamic changes during caesarean delivery in patients with severe preeclampsia: a randomized trial

BACKGROUND

Preoperative remifentanil administration blunts hemodynamic responses to tracheal intubation in parturients with severe preeclampsia. We hypothesized that the preoperative administration of low doses of remifentanil or dexmedetomidine would lead to comparable maternal neurohormonal responses and neonatal outcomes in patients with severe preeclampsia.

METHODS

Parturients diagnosed with severe preeclampsia undergoing caesarean delivery were randomLy allocated to receive remifentanil (0.1 µg/kg/min) or dexmedetomidine (0.4 µg/kg/h) at five min and 20 min before induction, respectively. Changes in maternal mean arterial BP(MAP), clinical recovery, cortisol level, and neonatal outcome, were recorded.

RESULTS

Patients who received remifentanil had higher response in MAP at the induction (94 9.8 vs. 104 4.5; P<0.001) and emergence from anesthesia (94 6.3 vs. 98 5.1; P<0.001), but shorter times to extubation (5.1 1.6 vs. 13.5 2.8 min; P<0.001). Five (27.8%) patients in the remifentanil group received ephedrine versus none in the dexmedetomidine group (P=0.023). The maternal plasma cortisol levels, the neonatal Neurologic and Adaptative Capacity Scores and acid-base satuses were similar in the two groups. Newborns in the remifentanil group presented lower Apgar scores at 1 minute (5.11 0.8 vs. 5.68 0.8; P=0.034) and a higher incidence of respiratory depression (72.2% vs. 36.8% P=0.048).

CONCLUSIONS

Compared with dexmedetomidine (0.4 µg/kg/h), the preoperative administration of remifentanil (0.1 µg/kg/min) produced a significantly higher effect on maternal hemodynamic responses to caesarean delivery in patients with severe preeclampsia, however maternal hypotension and neonatal respiratory depression were more common with the use of remifentanil.

The use of remifentanil during general anesthesia for caesarean section

PURPOSE OF REVIEW

The purpose is to review the neonatal and maternal effects of remifentanil given at induction of general anesthesia for caesarean section and prior to delivery of the baby.

MAIN FINDINGS

Remifentanil seems to have short-lived respiratory depressant effects in approximately 50% of neonates, requiring short periods of mask ventilation or tactile stimulation of the neonate. Remifentanil produces excellent maternal hemodynamic stability avoiding tachycardia and hypertension, possibly reducing the risk of maternal awareness.

SUMMARY

Remifentanil can be safely used at induction of general anesthesia provided healthcare workers are available to manage short-lived neonatal depression.

Maternal and Neonatal Effects of Remifentanil in Women Undergoing Cesarean Section in Relation to ABCB1 and OPRM1 Polymorphisms

The aim of our study was to evaluate possible effect of ABCB1, and OPRM1 polymorphisms on the efficacy and safety of remifentanil in women undergoing elective cesarean section under general anesthesia. Women received remifentanil (1 µg/kg i.v.) 30 s prior to the induction to standardized general anesthesia. The ABCB1 (rs2032582, rs1045642) and OPRM1 (rs1799971) polymorphisms were analyzed from maternal peripheral blood. The basal hemodynamic and demographic parameters in the study population (n=54) were similar in all the subgroups. The median ± SD increase of systolic blood pressure at 5 min from the baseline was practically completely abolished in homozygous carriers of ABCB1 variants in comparison with wild-type subjects -2.67±25.0 vs. 16.57±15.7 mm Hg, p<0.05 for rs2032582, and 2.00±23.9 vs. 22.13±16.8 mm Hg, p<0.05, for rs1045642, respectively. While no neonate belonging to ABCB1 wild-type homozygous or OPRM1 variant carrying mothers needed any resuscitative measure, 10.5 % of the neonates belonging to OPRM1 wild-type homozygous mothers received resuscitative support similarly as 11.1 %, and 12.5 % of neonates of mothers carrying variants of rs2032582, and rs1045642, respectively. Decreased stabilizing effects of remifentanil on maternal hemodynamics has been observed in ABCB1 wild type mothers, while the adaptation of the neonates was clinically worse in OPRM1 wild type, and ABCB1 variant allele carriers.

Neonatal effect of remifentanil in general anaesthesia for caesarean section: a randomized trial

Background

Remifentanil has been suggested for its short duration of action to replace standard opioids for induction of general anaesthesia in caesarean section. While the stabilizing effect of remifentanil on maternal circulation has been confirmed, its effect on postnatal adaptation remains unclear, as currently published studies are not powered sufficiently to detect any clinical effect of remifentanil on the newborn.

Methods

Using a double-blinded randomized design, a total of 151 parturients undergoing caesarean delivery under general anaesthesia were randomized into two groups – 76 patients received a bolus of remifentanil prior to induction, while 75 patients were assigned to the control group. Remifentanil 1 μg/kg was administered 30 seconds before the standard induction of general anaesthesia. The primary outcome measure was an assessment of neonatal adaptation using the Apgar score, while secondary outcomes included the need for respiratory support after delivery and differences in umbilical blood gas analysis (Astrup).

Results

The incidence of lower Apgar scores between 0 and 7 was significantly higher in the remifentanil group at one minute (25% vs. 9.3% of newborns, p = 0.017); whilst at five minutes and later no Apgar score differences were observed. There was no difference in the need for moderate (nasal CPAP) or intensive (intubation) respiratory support, but significantly more neonates in the remifentanil group required tactile stimulation for breathing support (21% vs. 7% of newborns, p = 0.017). There was no difference in the parameters from umbilical cord blood gas analysis between the groups.

Conclusion

At a dose of 1 μg/kg, remifentanil prior to induction of general anaesthesia increases the risk of neonatal respiratory depression during first minutes after caesarean delivery but duration of clinical symptoms is short.

Trial registration

ClinicalTrials.gov: NCT01550640.

Remifentanil patient-controlled analgesia for labor - monitoring of newborn heart rate, blood pressure and oxygen saturation during the first 24 hours after delivery

INTRODUCTION

There is no available information about the effects of remifentanil labor analgesia on newborns' vital signs in the first hours after delivery. The aim of the study was to assess changes in the heart rate, blood pressure and oxygen saturation during the first 24 h of neonatal life after using remifentanil patient-controlled analgesia (PCA) for labor analgesia.

MATERIAL AND METHODS

Forty-four full-term neonates, 23 from intravenous PCA remifentanil labor anesthesia 0.2 µg/kg, repeated not more frequently than every 2 min, and 21 born to mothers without any pharmacological forms of analgesia, were studied. Heart rate, oxygen saturation, and systolic (SBP) and diastolic blood pressure (DBP) were monitored using a Nellcor Oxi Max monitor N5500 (Tyco Healthcare), and recorded at 1 h, 6 h, 12 h and 24 h.

RESULTS

No significant differences in heart rate (p = 0.54; p = 0.26; p = 0.60; p = 0.83), oxygen saturation (p = 0.21; p = 0.27; p = 0.61; p = 0.9) and DBP (p = 0.98; p = 0.31; p = 0.83; p = 0.58) between the groups at 1 h, 6 h, 12 h and 24 h. Newborns from the remifentanil group had lower SBP at 1 h of life (59 mm Hg vs. 68.5 mm Hg) but the difference was just on the borderline of statistical significance (p > 0.06). There were no significant differences in SBP between the groups at 6 h (p = 0.65), 12 h (p = 0.11), and 24 h (p = 0.89) of life.

CONCLUSIONS

Remifentanil PCA analgesia during labor does not significantly modify the oxygen saturation, heart rate and blood pressure in infants during the first day of their life. Therefore, further studies are needed to explain the observed trend for arterial hypotension in the first hour of life in infants born to mothers treated with remifentanil.

Maternal and foetal effects of remifentanil for general anaesthesia in parturients undergoing caesarean section: a systematic review and meta-analysis

BACKGROUND

Remifentanil has been suggested for the induction of general anaesthesia for caesarean section. We aimed to define remifentanil effects on maternal stress response as well as neonatal effects.

METHODS

Relevant articles were retrieved by a systematic literature search. Randomized, controlled trials comparing remifentanil use before delivery with placebo were selected. Maternal outcome parameters were blood pressure and heart rate; neonatal effects included the need for mask ventilation and intubation, base excess, pH values, Apgar < 7 at 1 and 5 min. The random effects model was used for meta-analysis; risk ratio or weighted mean difference (WMD) and 95% confidence interval (95% CI) were calculated.

RESULTS

Five articles including 186 patients were identified. Highest and lowest systolic blood pressure were significantly lower in the remifentanil group (WMD: -29.98, -50.90 to -9.07 mmHg, 95% CI; P = 0.005; and WMD: -12.46, -18.21 to -6.71 mmHg, 95% CI; P < 0.0001), the lowest heart rate was significantly lower after remifentanil treatment (WMD: -8.22, -11.67 to -4.78, 95% CI; P < 0.00001). Base excess was significantly higher in infants of remifentanil-treated mothers (WMD: 1.15, -0.27 to 2.03, 95% CI; P = 0.01); pH was also higher in the remifentanil group, but significance was missed (P = 0.07). No differences were observed for Apgar values or the need of airway assist.

CONCLUSION

Remifentanil was found to attenuate the maternal circulatory response to intubation and surgery. Higher base excess and pH suggest a beneficial effect on the neonatal acid-base status. A trial with adequate power is warranted that addresses neonatal side-effects of remifentanil.

Comparison of remifentanil and fentanyl regarding hemodynamic changes due to endotracheal intubation in preeclamptic parturient candidate for cesarean delivery

BACKGROUND

Intravenous opioids are administered to prevent and control hemodynamic changes due to endotracheal intubation. Except for special cases such as preeclampsia, these drugs are not recommended for parturants candidate for cesarean section because of the respiratory depression caused in the newborn.

OBJECTIVES

According to rapid metabolism of remifentanil, the current study aimed to compare hemodynamic changes in preeclamptic parturants who received remifentanil and fentanyl for cesarean section under general anesthesia.

PATIENTS AND METHODS

This single blind randomized clinical trial was performed on preeclamptic pregnant women candidate for cesarean section under general anesthesia. They were divided into two groups. In the first group 0.05 μg/kg/min remifentanil was infused for 3 minutes before induction of anesthesia and in the second group 1ml (50 μg) fentanyl was injected before induction. Heart rate (HR), systolic blood pressure (SBP) and diastolic blood pressure (DBP) before and after intubation and also Apgar index were measured and compared between the two groups.

RESULTS

All hemodynamic variables increased after intubation in the fentanyl group (pSBP = 0.146, pDBP = 0.019, pHR < 0.001). Additionally, decrease in SBP (P = 0.018) and DBP (P = 0.955) and mild increase in HR (P = 0.069) after intubation in the remifentanil group was observed. No significant difference was found between Apgar indexes of the two groups (P = 0.771).

CONCLUSIONS

It can be postulated that remifentanil can be used in partituents candidate for cesarean delivery under general anesthesia to prevent severe increase in blood pressure and heart rate during tracheal intubation without adverse effects on newborn.