A dose–response study of remifentanil for attenuation of the hypertensive response to laryngoscopy and tracheal intubation in severely preeclamptic women undergoing caesarean delivery under general anaesthesia

Effect of continuous spinal anesthesia on the hemodynamics of labor analgesia in hypertensive pregnant women: a comparative, randomized clinical trial

BACKGROUND

To observe the changes in hemodynamic, stress and inflammatory responses during labor and their labor outcomes after continuous spinal anesthesia labor analgesia for hypertensive pregnant women, and to evaluate whether the continuous spinal anesthesia had any advantages compared to continuous epidural analgesia for hypertensive pregnant women and their newborns.

METHODS

A total of 160 hypertensive pregnant women were selected and randomly divided into continuous spinal anesthesia analgesia group (CSA group) and continuous epidural analgesia group (EA group). Participant age, height, weight and gestational week were recorded; MAP, VAS score, CO and SVR were recorded after the onset of regular uterine contractions (T₀), 10 min after analgesia (T₁), 30 min (T₂), 60 min (T₃), when the uterine opening was complete (T₄) and when the fetus was delivered (T₅); the duration of the first stage of labor and the second stage of labor were recorded; the number of cases of treatment with oxytocin and antihypertensive therapy, mode of delivery, eclampsia and postpartum hemorrhage were counted; pregnant women Bromage scores were recorded at T₂. We also recorded neonatal weight, Apgar scores at 1, 5 and 10 min after birth; arterial blood gas analysis of the umbilical cord was performed in newborns; finally, TNF-α, IL-6, and cortisol in pregnant women venous blood were measured at T₀, T₅, and 24 h after delivery (T₇). The number of successful compressions and the total drug dosage administered by the analgesic pump were recorded for both groups.

RESULTS

The first stage of labor in CSA was longer than EA (P < 0.05); the MAP, VAS and SVR value in CSA were lower than EA group at T₁, T₃ and T₄ (P < 0.05); in contrast, the CO in CSA at T3 and T4 was higher than in EA (P < 0.05). The oxytocin was more often used whereas the antihypertensive drugs were less used in CSA as compared to EA. The level of TNF-α, IL-6, Cor in the CSA at T5 was lower than the EA group (P < 0.05), and the level of TNF-α in the CSA group at T7 was lower than the EA group (P < 0.05).

CONCLUSION

For pregnant women with hypertension during pregnancy, continuous spinal anesthesia labor analgesia has no significant effect on the final mode of delivery, but shows precise analgesic effect and stabilizes circulatory system, it is recommended to perform continuous spinal anesthesia early in labor for hypertensive pregnant women, which can effectively reduce the stress reaction.

TRIAL REGISTRATION

ChiCTR-INR-17012659. Date of registration: 13/09/2017.

Possibility to use quanadex (dexmedetomidine) for caesarean section in patients with pre-eclampsia

A prospective, double­blind, randomized, con­trolled clinical trial was conducted at the Republican Spe­cialized Scientific and Practical Medical Center of Obstet­rics and Gynecology of the Ministry of Health of the Repub­lic of Uzbekistan. The inclusion criteria for pregnant wom­en in the study was preeclampsia. All women were divided into 2 groups. In group I, premedication was performed on the table with sibazon 5 mg. In group II, starting from the moment of premedication, 0.5 µg/kg of quanadex (Yuriya Pharm) was administered intravenously for 15 minutes. The maintaining dose was 0.5–0.8 µg/kg/h. 0.5 % hyper­baric longocaine heavy was administered intrathecally at the LII–LIV level. Hemodynamics was assessed by echocardi­ography. BAC and electrolytes, lactate, glucose, hematocrit were studied on a gas analyzer “BGA­102” Wondfo (Rain Sen Da), NTproBNP, Cystatin­C, interleukin­6 and protein S­100 were determined on an immunofluorescence ana­lyzer Finecare™ FIA MeterPlus/FS 113 (Wonfo), sedation was assessed using the Richmond scale. Newborns were assessed for Apgar scores in the 1st and 5th minutes.The data obtained showed that patients randomized to the group with dexmedetomidine (Group II) were almost al­ways better able to awaken than patients in the group with sibazon, and were distinguished by better hemodynamic stability, antinociceptive protection for surgical and anes­thetic intervention, without pronounced arterial hypoten­sion and bradycardia. It did not cause significant adverse outcomes in newborns.

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.

Pharmacologic strategies to prevent hemodynamic changes after intubation in parturient women with hypertensive disorders of pregnancy: A systematic review and network meta-analysis protocol

BACKGROUND

Hypertensive disorders of pregnancy are major health issues affecting mothers and infants. General anesthesia is inevitable for certain mothers with these conditions and they may exhibit pronounced hemodynamic instability, especially during induction and airway manipulation. The aims of this study are to combine direct and indirect comparisons of the efficacies of different medications used in attenuating reflex hemodynamic responses and generate intervention ranking by network meta-analysis (NMA).

METHODS

A systematic and comprehensive search will be performed using MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), and Google Scholar databases, beginning from their inceptions to November 2019. Only randomized clinical trials evaluating the efficacy and safety of pharmacologic interventions for preventing hemodynamic changes after intubation in parturient women with hypertensive disorders of pregnancy will be included. The primary endpoints will be maximal mean arterial pressure (MAP) and maximal heart rate after intubation. Maximal systolic arterial pressure (SAP), diastolic arterial pressure (DAP), and maternal/fetal blood gas analysis, as well as safety issues, including Apgar score at 1 minute and 5 minutes after delivery, will be also assessed.We will conduct both pairwise meta-analysis and network meta-analysis. We will use surface under the cumulative ranking curve (SUCRA) values and rankograms to present the hierarchy of pharmacologic interventions. A comparison-adjusted funnel plot will be used to assess the presence of small-study effects. The quality of the studies included will be assessed using the risk of bias tool 2.0. All statistical analyses will be performed using Stata SE, version 15.0 (StataCorp, College Station, TX).

RESULTS

The results of this systematic review and NMA will be published in a peer-reviewed journal.

CONCLUSION

This NMA will enable us to determine the order of effectiveness and safety of pharmacological interventions used in attenuating hemodynamic responses for mothers with hypertensive disorders of pregnancy.

TRIAL REGISTRATION NUMBER

CRD42019136067.

Effects of Vasoactive Medications and Maternal Positioning During Cesarean Delivery on Maternal Hemodynamics and Neonatal Acid-Base Status

Maternal hemodynamics, positioning, and anesthesia technique for cesarean delivery influence neonatal acid-base balance; direct effects from drugs that cross the placenta also have an influence. Spinal anesthesia limits fetal exposure to depressant drugs and avoids maternal airway instrumentation, but is associated with hypotension. Hypotension may be prevented/treated with vasopressors and intravenous fluids. Current evidence supports phenylephrine as the first-line vasopressor. Fifteen degrees of lateral tilt during cesarean delivery has been advocated to relieve vena caval obstruction, but routine use may be unnecessary in healthy nonobese women having elective cesarean delivery if maternal blood pressure is maintained near baseline.

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.

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.

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.

Practice Bulletin No. 177: Obstetric Analgesia and Anesthesia

Labor causes severe pain for many women. There is no other circumstance in which it is considered acceptable for an individual to experience untreated severe pain that is amenable to safe intervention while the individual is under a physician's care. Many women desire pain management during labor and delivery, and there are many medical indications for analgesia and anesthesia during labor and delivery. In the absence of a medical contraindication, maternal request is a sufficient medical indication for pain relief during labor. A woman who requests epidural analgesia during labor should not be deprived of this service based on the status of her health insurance. Third-party payers that provide reimbursement for obstetric services should not deny reimbursement for labor analgesia because of an absence of "other medical indications." Anesthesia services should be available to provide labor analgesia and surgical anesthesia in all hospitals that offer maternal care (levels I-IV) (). Although the availability of different methods of labor analgesia will vary from hospital to hospital, the methods available within an institution should not be based on a patient's ability to pay.The American College of Obstetricians and Gynecologists believes that in order to allow the maximum number of patients to benefit from neuraxial analgesia, labor nurses should not be restricted from participating in the management of pain relief during labor. Under appropriate physician supervision, labor and delivery nursing personnel who have been educated properly and have demonstrated current competence should be able to participate in the management of epidural infusions.The purpose of this document is to review medical options for analgesia during labor and anesthesia for surgical procedures that are common at the time of delivery. Nonpharmacologic options such as massage, immersion in water during the first stage of labor, acupuncture, relaxation, and hypnotherapy are not covered in this document, though they may be useful as adjuncts or alternatives in many cases.

Update in the Management of Patients with Preeclampsia

Hypertensive disorders of pregnancy complicate approximately 10% of all deliveries in the United States and are a leading cause of maternal and fetal morbidity and mortality. Preeclampsia is defined as hypertension in association with proteinuria, thrombocytopenia, impaired liver function, renal insufficiency, pulmonary edema, or new-onset cerebral or visual disturbances. The greatest risk factor for the development of preeclampsia is a history of preeclampsia. There currently is no effective means for the prevention of preeclampsia. Approximately 39% of patients diagnosed with preeclampsia have hypertension and approximately 20% have proteinuria 3 months postpartum. Preeclampsia increases the risk of patients developing hypertension later in life.

Hypertensive disorders of pregnancy

PURPOSE

In this continuing professional development module, we review recent Society of Obstetricians and Gynaecologists of Canada (SOGC) guidelines for the classification and diagnosis of hypertensive disorders of pregnancy (HDP) as well as review the clinical features, laboratory investigations, and outcomes of HDP. We explore the evidence for anesthetic management and prevention of end-organ damage in women with HDP and describe the role and contribution of anesthesiologists as part of a multidisciplinary care team.

PRINCIPAL FINDINGS

Hypertensive disorders of pregnancy can have variable presentations with clinical signs and symptoms that often do not correlate with the underlying severity and progression of the disease. Failure of timely diagnosis and treatment contributes significantly to adverse maternal (neurologic complications, pulmonary edema, and postpartum hemorrhage) and neonatal (respiratory and neurologic complications and stillbirth) outcomes. In the Canadian context, improvements in medical care have led to better maternal and neonatal outcomes. Timing of delivery is crucial in balancing maternal risks and fetal benefits of ongoing pregnancy. Evidence-based SOGC guidelines regarding diagnosis and management of HDP address many aspects of clinical care relevant to anesthesiologists, who have an important role in the multidisciplinary care team.

CONCLUSIONS

Hypertensive disorders of pregnancy are on the rise worldwide, and this trend is expected to continue. The major contributors to maternal mortality are failure to recognize HDP promptly or to treat the condition adequately. It is essential that anesthesiologists understand the disease process and acquire knowledge of the guidelines governing current obstetrical care in order to provide evidence-based multidisciplinary quality care to these patients. Anesthetic management helps prevent potentially deleterious maternal and fetal outcomes.

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.

Severe preeclampsia: what's new in intensive care?

Preeclampsia remains an important cause of avoidable maternal morbidity and mortality. Publication of guidelines and monitoring adherence to life-saving therapies should be prioritized. Prediction of fluid responsiveness requires individual hemodynamic investigation. Future studies are required to determine the optimal early warning system and monitoring tools for providing early and non-invasive hemodynamic assessment.