Effects of remifentanil on cardiovascular and bispectral index responses to endotracheal intubation in severe pre-eclamptic patients undergoing Caesarean delivery under general anaesthesia

Low-Dose Remifentanil in Preterm Cesarean Section with General Anesthesia: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVE

The conventional technique of general anesthesia induction during a Cesarean section involves the use of opioids only after cord clamping. We hypothesized that the use of remifentanil before cord clamping might reduce the use of maternal supplemental anesthetic agents and improve the maternal hemodynamics status and neonatal adaptation of the preterm neonate.

METHODS

A phase III, double-blind, randomized, placebo-controlled, hospital-based trial enrolled parturients undergoing a Cesarean section under general anesthesia before 37 weeks of gestation. Block randomization allocated pregnant women to remifentanil or placebo. The primary outcome was the rate of newborns with Apgar scores < 7 at 5 min. Secondary outcomes were maternal hemodynamic parameters, complications of anesthetic induction, use of adjuvant anesthetic agents, neonatal respiratory distress, umbilical cord pH, and lactate levels.

RESULTS

A total of 52/55 participants were analyzed, comprising 27 women in the remifentanil group and 25 in the placebo group. Nine of 27 (33.3%) neonates had an Apgar score < 7 at 5 min in the remifentanil group versus 11/25 (44.0%) in the placebo group (p = 0.45, odds ratio = 0.66, 95 confidence interval 0.20-2.18). The blood cord gases, cognitive, behavior, sensory, sleeping, and feeding scores at 1 and 2 years of corrected age were not different. For the mothers, hemodynamic parameters, anesthesia duration, and the cumulative treatment dose until cord clamping did not differ between the groups.

CONCLUSIONS

The use of a low dose of remifentanil before cord clamping for a Cesarean section appears to be safe both for the mother and the preterm newborn, but it does not improve maternal or neonatal outcomes.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov: NCT02029898.

The effect-site concentration of remifentanil blunting endotracheal intubation responses during anesthesia induction with etomidate: a dose-finding study

BACKGROUND

Remifentanil can inhibit the hemodynamic responses caused by endotracheal intubation, but the effect-site concentration of it required to control intubation responses when combined with etomidate has not been demonstrated. The purpose of this study was to determine the effect-site concentration of remifentanil blunting tracheal intubation responses in 50% and 95% of patients (EC₅₀ and EC₉₅) during etomidate anesthesia.

METHODS

American Society of Anesthesiologists physical status (ASA) I-II elective surgical patients receiving target-controlled infusion (TCI) of remifentanil, followed by etomidate and rocuronium for anesthesia were enrolled. The Belive Drive A2 monitor was used to calculate the MGRSSI (Maygreen Sedative state index) of hypnotic effect and the MGRNOX (Maygreen Nociception index) of nociception. The MGRSSI and the MGRNOX value were generated every 1 s. Mean arterial pressure (MAP) and heart rate (HR) were measured every minute, noninvasively. Using the modified Dixon's up-and-down method, the concentration of remifentanil was determined based on the intubation response of the previous patient. The cardiovascular response during endotracheal intubation was defined as positive when MAP or HR is 20% higher than the pre-intubation value. A probit analysis was used for calculating EC₅₀, EC₉₅ and 95% confidence interval (CI).

RESULTS

The EC₅₀ and EC₉₅ of remifentanil blunting tracheal intubation responses were found to be 7.731 ng/ml (95%CI: 7.212-8.278 ng/ml) and 8.701 ng/ml (95%CI: 8.199-11.834 ng/ml). There were statistically significant increases in HR, MGRSSI and MGRNOX value to tracheal intubation in the positive responses group compared to the negative group. The most common adverse event was postoperative nausea and vomiting, which occurred in 3 patients.

CONCLUSION

Remifentanil effect-site concentration of 7.731 ng/ml is effective in blunting sympathetic responses to tracheal intubation in 50% of patients when combined with etomidate anesthesia.

TRIAL REGISTRATION

The trial was registered at the Chinese Clinical Trials Registry ( www.chictr.org.cn , registration number: ChiCTR2100054565, date of registration: 20/12/2021).

Preoperative lignocaine nebulisation for attenuation of the pressor response of laryngoscopy and tracheal intubation in patients with severe preeclampsia undergoing caesarean section delivery: A randomised double-blind controlled trial

Background and Aims

Following induction of general anaesthesia, direct laryngoscopy and endotracheal intubation usually cause tachycardia and hypertension due to increased sympathetic activity. This response is generally exaggerated in hypertensive patients. This study aimed to evaluate the effectiveness of preoperative lignocaine nebulisation in attenuating the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery.

Methods

After ethical approval, we conducted this randomised, double-blind study, which included 110 patients with severe preeclampsia who underwent caesarean delivery under general anaesthesia. These patients were randomly allocated into two groups to receive either preoperative nebulisation of lignocaine 2% in a dose of 4.5 mg/kg (not exceeding 400 mg) in the lignocaine group or nebulisation of an equivalent volume of 0.9% NaCl in the saline group. The primary objective was the systolic blood pressure after tracheal intubation. The secondary objectives included heart rate, maternal serum cortisol and blood glucose levels, grade of cough during emergence, postoperative sore throat and hoarseness of voice, neonatal Apgar score and umbilical blood gas.

Results

The systolic blood pressure was significantly lower in the lignocaine group compared to the saline group at 1, 3 and 5 min after endotracheal intubation and after delivery of the foetus (P = 0.001, 0.003, 0.002 and 0.019, respectively). Similarly, the heart rate was significantly lower in the lignocaine group versus saline group at 1 and 3 min after endotracheal intubation (P = 0.041 and 0.042, respectively).

Conclusion

Preoperative lignocaine nebulisation in a dose of 4.5 mg/kg effectively attenuated the pressor response to laryngoscopy and endotracheal intubation in patients with severe preeclampsia undergoing caesarean delivery.

Effect of intravenous dexmedetomidine and remifentanil on neonatal outcomes after caesarean section under general anaesthesia: A systematic review and meta-analysis

BACKGROUND

Various strategies have been used to mitigate haemodynamic instability during general anaesthesia for caesarean section. However, the safety of these strategies for neonates remains controversial.

OBJECTIVE

To investigate the effects of intravenous dexmedetomidine and remifentanil on neonatal outcomes during caesarean section under general anaesthesia.

DESIGN

Systematic review and meta-analysis of randomised controlled trials.

DATA SOURCES

Databases of PubMed, EMBASE and CENTRAL were searched until March 2020 and updated in February 2021.

ELIGIBILITY CRITERIA

Randomised controlled trials were included if they compared dexmedetomidine and remifentanil infusion on neonatal outcomes after elective caesarean section under general anaesthesia. Primary outcomes were 1 and 5 min Apgar scores. Secondary outcomes were the incidence of neonatal mask ventilation or endotracheal intubation, and pH of the umbilical artery and vein. Studies that did not report primary outcomes were excluded.

RESULTS

Five studies with 258 patients in total were included. The Apgar score at 1 min in the remifentanil group was lower than that in the dexmedetomidine group for both quantitative [weighted mean difference (WMD): 0.75; 95% CI, 0.44 to 1.07; τ2 = 0.00] and categorical outcomes (≥Apgar 7 vs.

CONCLUSION

In our study, Apgar score at 1 min reported using both quantitative and categorical variables were lower in the remifentanil group than in the dexmedetomidine group but TSA showed that these differences were inconclusive for categorical variables. Data for other outcomes were scarce and did not allow any conclusions to be drawn. Thus, further studies with larger numbers of parturients and with neonatal outcomes as a primary endpoint are warranted to clarify the effects of intravenous dexmedetomidine and remifentanil.

TRIAL REGISTRATION

The protocol of this study has been registered in PROSPERO (CRD42019141102).

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MESH Headings

• Anesthesia, General/adverse effects
• Cesarean Section
• Dexmedetomidine/adverse effects
• Female
• Humans
• Infant, Newborn
• Piperidines/adverse effects
• Pregnancy
• Remifentanil

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Guidelines for the management of women with severe pre-eclampsia

OBJECTIVE

To provide national guidelines for the management of women with severe pre-eclampsia.

DESIGN

A consensus committee of 26 experts was formed. A formal conflict-of-interest (COI) policy was developed at the onset of the process and enforced throughout. The entire guidelines process was conducted independently of any industrial funding. The authors were advised to follow the principles of the Grading of Recommendations Assessment, Development and Evaluation (GRADE®) system to guide assessment of quality of evidence. The potential drawbacks of making strong recommendations in the presence of low-quality evidence were emphasised.

METHODS

The last SFAR and CNGOF guidelines on the management of women with severe pre-eclampsia were published in 2009. The literature is now sufficient for an update. The aim of this expert panel guidelines is to evaluate the impact of different aspects of the management of women with severe preeclampsia on maternal and neonatal morbidities separately. The experts studied questions within 7 domains. Each question was formulated according to the PICO (Patients Intervention Comparison Outcome) model and the evidence profiles were produced. An extensive literature review and recommendations were carried out and analysed according to the GRADE® methodology.

RESULTS

The SFAR/CNGOF experts panel provided 25 recommendations: 8 have a high level of evidence (GRADE 1+/-), 9 have a moderate level of evidence (GRADE 2+/-), and for 7 recommendations, the GRADE method could not be applied, resulting in expert opinions. No recommendation was provided for 3 questions. After one scoring round, strong agreement was reached between the experts for all the recommendations.

CONCLUSIONS

There was strong agreement among experts who made 25 recommendations to improve practices for the management of women with severe pre-eclampsia.

Pharmacological strategies to prevent haemodynamic changes after intubation in parturient women with hypertensive disorders of pregnancy: A network meta-analysis

Objective : This network meta-analysis (NMA) aimed to determine the relative efficacy and safety of pharmacological strategies used to mitigate haemodynamic instability by intubation for general anaesthesia in hypertensive parturient women undergoing caesarean section. Methods : We considered randomised controlled studies comparing the effects of pharmacological strategies used to alleviate haemodynamic instability during intubation in parturient women with hypertensive disorders of pregnancy. The primary endpoints were maximum blood pressure and heart rate after intubation, and secondary endpoints were the Apgar scores at 1 and 5 min. NMA allowed us to combine direct and indirect comparisons between strategies. Results : Twelve studies evaluating nine pharmacological strategies in 619 patients were included. According to the surface under the cumulative ranking curve, the maximal mean arterial pressure was lowest for high-dose remifentanil (99.4%) followed by nitroglycerin (73.6%) and labetalol (60.9%). The maximal heart rate was lowest for labetalol (99.9%) followed by high dose of remifentanil (81.2%) and fentanyl (61.6%). Apgar score at 1 min was higher with low-dose than with high-dose remifentanil (mean difference, 0.726; 95% confidence interval, 0.056 to 1.396; I²=0.0%). Conclusions : High-dose remifentanil produces minimum blood pressure changes, while labetalol is most effective in maintaining normal heart rate in parturient women with hypertensive disorders of pregnancy during caesarean section under general anaesthesia.

Comparison of Intravenous Nalbuphine and Paracetamol on Maternal Hemodynamic Status, Neonatal APGAR Score, and Postoperative Pain given before Induction of General Anesthesia for Elective Cesarean Section

Background:

Stress response to endotracheal intubation and surgery is associated with exaggerated hemodynamic response and an increase in catecholamine levels which is deleterious to both the mother and fetus. We aimed to compare the effects of intravenous nalbuphine and paracetamol on maternal hemodynamic status, neonatal APGAR score, and postoperative pain using the visual analog scale for elective cesarean section under general anesthesia.

Study Design:

This was a prospective, randomized, double-blinded clinical study.

Materials and Methods:

Sixty full-term pregnant patients, belonging to the American Society of Anaesthesiologist physical status Classes I and II, scheduled for elective cesarean section under general anesthesia were enrolled for the study. The patients were randomly allocated into two groups of 30 patients each to receive paracetamol (15 mg.kg^{− 1}) in Group Pand nalbuphine (0.2 mg.kg⁻¹) in Group N before induction of general anesthesia. Maternal heart rate, blood pressure, and oxygen saturation were recorded before infusion of study drugs, after induction, after intubation, and during surgery across all periods. APGAR score of neonates was recorded by a pediatrician. Time to reach visual analogue score-1 was recorded.

Results:

Significant attenuation of maternal hemodynamic response was observed with nalbuphine compared to the paracetamol group (P < 0.05). The time to achieve visual analogue score-1 in the postoperative period was higher in the nalbuphine group. APGAR score at 1 min was significant between the groups and at 5 min, nonsignificant difference was observed (P > 0.05).

Conclusion:

Nalbuphine and paracetamol are effective in perioperative hemodynamic stability of mother and APGAR score of neonates. However, nalbuphine had better hemodynamic stability as compared to paracetamol with a comparable APGAR score at 5 min.

Effects of dexmedetomidine versus remifentanil on mothers and neonates during cesarean section under general anesthesia

BACKGROUND AND AIMS

Dexmedetomidine and remifentanil use in obstetric general anesthesia is controversial. This study aimed to compare the effects of remifentanil and dexmedetomidine on mothers and neonates during cesarean section under general anesthesia.

METHODS

A total of 120 patients scheduled for elective cesarean section under general anesthesia were randomly allocated to dexmedetomidine (D), remifentanil (R), and control (C) groups. Anesthesia was induced with propofol and muscle relaxants in all groups. Anesthesia in groups D and R was induced with dexmedetomidine (induction, 0.5 µg/kg; maintenance, 0.5 µg/kg.h) and remifentanil (induction, 0.5 µg/kg; maintenance, 2 µg/kg.h), respectively, until birth. Group C received equivalent volumes of normal saline. Mean arterial blood pressure (MAP), heart rate (HR), plasma catecholamine, visual analog pain score (VAS), and total tramadol consumption at 1, 2, and 3 hours after extubation were recorded. Neonatal effects were assessed by Apgar scores and umbilical blood gas analysis.

RESULTS

Post induction, MAP was significantly higher in group D compared to groups C and R, and significantly lower in group R than in group C. At intubation/skin incision and delivery, MAP, HR, and plasma epinephrine and norepinephrine concentrations were significantly lower in groups D and R than in group C. Compared to group R, MAP was significantly higher, and HR, plasma epinephrine, and norepinephrine concentrations were significantly lower in group D. Compared with groups C and D, the percentage of neonates with Apgar score < 7 was higher in group R at 1 min after delivery. Compared with groups C and R, the VAS was significantly lower in group D at 1 and 2 h postoperatively. Total tramadol consumption was significantly lower in group D at 3 hours postoperatively.

CONCLUSION

During general anesthesia for cesarean section, remifentanil demonstrated better control of hemodynamic stability, while dexmedetomidine demonstrated better neonatal Apgar scores, postoperative analgesia, and decreased catecholamine release.

TRIAL REGISTRATION

Chinese Clinical Trial Register (ChiCTR) - ChiCTR1800017125.

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.

Effects of remifentanil and dexmedetomidine on the mother's awareness and neonatal Apgar scores in caesarean section under general anaesthesia

Objective

This study aimed to compare the effects of remifentanil and dexmedetomidine on awareness during the induction of general anaesthesia.

Material and Methods

Ninety patients scheduled for elective caesarean section under general anaesthesia were included and randomly divided into three anaesthesia groups: 2 mg/kg propofol (control group); 2 mg/kg propofol and 1 µg/kg dexmedetomidine (dexmedetomidine group); and 2 mg/kg propofol and 1 µg/kg remifentanil (remifentanil group). All patients received routine monitoring, and Apgar scores at 1 and 5 minutes were recorded. The bispectral index and the isolated forearm technique were used to determine the depth of anaesthesia.

Results

Bispectral index values at skin and uterine incisions and at delivery were similar among the groups. The number of patients who responded positively to the isolated arm technique during the induction period was also similar. One-minute Apgar scores in the control group were significantly lower and 5-minute Apgar scores significantly higher than those in the other groups.

Conclusion

The effects of remifentanil and dexmedetomidine added to propofol on maternal awareness, neonatal Apgar scores, and bispectral index values were similar compared with propofol alone. However, it was observed that remifentanil controlled the haemodynamic responses to sympathetic stimuli in a better manner than dexmedetomidine.

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.

Efficacy and safety of remifentanil for analgesia in cesarean delivery

BACKGROUND

This study aimed to assess the efficacy and safety of remifentanil as a general anesthetic during cesarean delivery.

MATERIAL AND METHODS

Fifty women with singleton pregnancies undergoing cesarean delivery were randomly divided into intervention and control groups, each group containing 25 subjects. Participants in the intervention group received remifentanil (infused at 2 μg/kg/h), whereas subjects in the control group were given dexmedetomidine (infused at 0.4 μg/kg/h). Outcome measurements included mean arterial blood pressure (MAP), heart rate (HR), bispectral index (BIS), Apgar scores at 1 and 5 minutes, and the pH, PCO2, PO2, and base excess (BE) of umbilical venous and arterial blood.

RESULTS

Forty-four participants completed the study. Patients in the intervention group did not experience greater effect and safety than those in the control group (P > .05), although MAP and BIS values decreased significantly immediately before laryngoscopy (P < .05). In addition, BIS values were reduced significantly at the time of skin incision, at uterine incision, and immediately after fetal delivery when compared with baseline values in both groups (P < .01).

CONCLUSION

This study concluded that remifentanil and dexmedetomidine exhibited similar efficacy and safety during general anesthesia for cesarean delivery.

Peri-operative management of caesarean section for the occasional obstetric anaesthetist – an aide memoire

Anaesthesia practice for caesarean section (CS) has evolved in the past 20 years. This article aims to update occasional obstetric anaesthesiologists, obstetricians and clinicians involved in the management of pregnant women on the latest guidelines and recommendations for anaesthesia management, including pre-operative evaluation, informed consent, intra-operative and postoperative management for CS. In addition, this article will also summarise the management of CS associated emergencies such as difficult intubation, obstetric major postpartum haemorrhage, local anaesthetic toxicity and (pre-) eclampsia. At the end of the article, a charted summary will be provided as an aide memoire.

Comparative Evaluation of Remifentanil and Dexmedetomidine in General Anesthesia for Cesarean Delivery

Background

Use of remifentanil and dexmedetomidine in general anesthesia for cesarean section have been described. This study was designed to evaluate the effects of remifentanil and dexmedetomidine on maternal hemodynamics and bispectral index, and neonatal outcomes in elective caesarean delivery.

Material/Methods

Forty-four women undergoing elective cesarean delivery with ASA I or II and term or near-term singleton pregnancies were randomly assigned to receive remifentanil at a loading dose of 2 μg/kg over 10 min followed by a continuous infusion of 2 μg/kg/h until about 6 min before fetal delivery (Group REM), or dexmedetomidine at a loading dose of 0.4 μg/kg over 10 min followed by a continuous infusion of 0.4 μg/kg/h until about 6 min before fetal delivery (Group DEX). Maternal hemodynamics and BIS values were recorded. Neonatal effects were assessed using Apgar scores and umbilical cord blood gas analysis.

Results

Mean arterial pressure (MAP) increased after intubation in both groups, and the change magnitude of the MAP was higher in Group DEX (P<0.05). Patients in Group DEX had a lower BIS value at recovery and consumed less propofol during surgery (P<0.05). The incidences of neonatal resuscitation at 1 min were 81.8% in Group REM and 54.5% in Group DEX (P=0.052). There was no significant difference in either group in Apgar scores at 1 and 5 min and umbilical cord blood gas values.

Conclusions

Both remifentanil and dexmedetomidine are effective to blunt hemodynamic responses to intubation and also seem safe for neonates at the administrated doses, but remifentanil still has the potential to cause neonatal transient respiratory depression.

Pre-delivery remifentanil infusion for placenta accreta cesarean delivery under general anesthesia: an observational study

OBJECTIVE

General anesthesia may be required for placenta accreta cesarean delivery. Intrauterine fetal anesthetic exposure should be minimized to avoid neonatal respiratory depression; opioids are often delayed until post-delivery.

METHODS

In this observational study, we compared neonatal outcome using pre-delivery remifentanil versus post-delivery (deferred) opioids for placenta accreta cesarean delivery. Choice of anesthesia was discretionary. The primary outcome was Apgar score at 5 min comparing women who received pre-delivery remifentanil versus deferred opioid administration. We recorded maternal/obstetric characteristics, surgical characteristics, maternal hemodynamic data, neonatal outcomes: Apgar scores, umbilical vein pH and respiratory interventions at birth.

RESULTS

Between February 2007 and April 2014 we identified 40 general anesthesia placenta accreta cesarean deliveries. The remifentanil dose rate ranged from 0.06 to 0.46 mcg kg(-1 )min(-1). Obstetric and maternal characteristics were similar. Neonatal Apgar, umbilical pH and respiratory intervention outcomes were similar in both groups; Apgar scores median (interquartile range IQR [range]) at 5 min were 9 (8-10) for pre-delivery remifentanil versus 9 (9-10) for deferred opioid administration, p = 0.18.

CONCLUSIONS

We did not observe a significant effect on neonatal Apgar scores at 1 and 5 min, or respiratory interventions at birth when remifentanil infusion was administered pre-delivery.

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.

Prevention of peri-induction hypertension in preeclamptic patients: a focused review

Many medications have been used to prevent the hypertensive response to the induction of general anesthesia and laryngoscopy in preeclamptic patients, with varying results. In this focused review, we summarize the available data and pharmacologic profiles of these drugs. Several different drug classes may be used safely; however, magnesium bolus, lidocaine, calcium channel antagonists other than nicardipine, and hydralazine are not recommended. Further research is warranted into the hemodynamic impact of varying the induction drug dose or combining different classes of drugs.

Focused review: spinal anesthesia in severe preeclampsia

Spinal anesthesia is widely regarded as a reasonable anesthetic option for cesarean delivery in severe preeclampsia, provided there is no indwelling epidural catheter or contraindication to neuraxial anesthesia. Compared with healthy parturients, those with severe preeclampsia experience less frequent, less severe spinal-induced hypotension. In severe preeclampsia, spinal anesthesia may cause a higher incidence of hypotension than epidural anesthesia; however, this hypotension is typically easily treated and short lived and has not been linked to clinically significant differences in outcomes. In this review, we describe the advantages and limitations of spinal anesthesia in the setting of severe preeclampsia and the evidence guiding intraoperative hemodynamic management.

[Anaesthetic management of patients with bicuspid aortic valve for delivery. About two consecutive cases]

Cardiac diseases are the second cause of non-obstetrical death during pregnancy in France. Bicuspid aortic valve is the most frequent congenital cardiac disease but its characteristics are little known. We report two consecutive cases of pregnant patients with aortic bicuspidy, one with a severe aortic stenosis and one with a severe dilatation of the ascending aorta. We describe the anaesthetic management of delivery for these two cases and summarize the current recommendations for management of this condition during pregnancy.

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.

Therapeutics and anaesthesia

Many aspects of hypertension care outside pregnancy may be applied in pregnancy, but little information is available on which to base decision-making. It would seem reasonable to continue previous dietary salt restriction and physical activity in women with pre-existing (and controlled) hypertension, encourage a heart-healthy diet in all women with a hypertension disorder of pregnancy, and take patient preference into account when deciding on place of care. Although bed rest has become a key part of obstetric practice and for care of women with a hypertension disorder of pregnancy, in particular, the evidence is lacking to support this practice. This may also increase thromboembolic risk. Antihypertensive treatment is strongly advised for women with severe hypertension. The most common agents are parenteral labetalol, hydralazine, or oral nifedipine capsules. Clinicians should familiarise themselves with multiple agents. Until the role of antihypertensive treatment for non-severe hypertension in pregnancy is clarified by ongoing research, clinicians should explicitly state an individual patient's blood pressure goal, which could reasonably be anywhere between 130/80 and 155/105 mmHg. Labetalol and methyldopa are used most commonly. Breastfeeding should be encouraged. Many risk factors for hypertension (e.g. obesity), as well as hospitalisation and pre-eclampsia, all increase the thromboembolic risk for pregnant women, and care providers should consider thromboprophylaxis in the appropriate setting. Finally, anaesthetists play a critical role in the management of women with a hypertension disorder of pregnancy, and should be involved earlier rather than later in the course of their care.

Inverted takotsubo-like left ventricular dysfunction with pulmonary oedema developed after caesarean delivery complicated by massive haemorrhage in a severe preeclamptic parturient with a prolonged painful labour

Inverted takotsubo cardiomyopathy (TTC), a variant of stress-induced cardiomyopathy, features transient myocardial dysfunction characterized by a hyperdynamic left ventricular apex and akinesia of the base. Herein, we describe a 38-year-old primigravida with severe preeclampsia who had active labour for 4 h followed by an emergency caesarean delivery. She developed postpartum haemorrhage due to uterine atony complicated by pulmonary oedema, which was managed with large-volume infusion and hysterectomy. Her haemodynamic instability was associated with cardiac biomarkers indicative of diffuse myocardial injury and echocardiographic findings of an “inverted” TTC. The patient was almost fully recovered one month later. Our case shows that a reversible inverted TTC may result from a prolonged painful labour. TTC should be listed in the differential diagnosis of the patient presenting with pulmonary oedema of unknown origin, especially in patients with severe preeclampsia.

Diagnosis and management of pre-eclampsia: an update

Pre-eclampsia is a significant, multifactorial, multiorgan disease affecting 5%-8% of all pregnancies in the US where it is the third leading cause of maternal mortality. Despite improvements in the diagnosis and management of pre-eclampsia, severe complications can occur in both the mother and the fetus, and there is no effective method of prevention. Early detection and identification of pregnant women most at risk of developing the disease have proven challenging, but recent efforts combining biochemical and biophysical markers are promising. Efforts at prevention of pre-eclampsia with aspirin and calcium have had limited success, but research on modifiable risk factors, such as obesity surgery, are encouraging. Obstetric management of severe pre-eclampsia focuses on medical management of blood pressure and prevention of seizures using magnesium sulfate, but the ultimate cure remains delivery of the fetus and placenta. Timing of delivery depends on several factors, including gestational age, fetal lung maturity, and most importantly, disease severity. Anesthetic management includes regional anesthesia with careful evaluation of the patient's airway, volume status, and coagulation status to reduce morbidity and mortality. The potential complications of general anesthesia, including intracranial hemorrhage, in these patients make regional anesthesia the preferred choice in many cases. Nevertheless, it is important to be aware of the contraindications to neuraxial anesthesia and to prepare always for the possibility of encountering a difficult airway.