Anesthetic modification of hemodynamic and neuroendocrine stress responses to cesarean delivery in women with severe preeclampsia

A systematic review with network meta-analysis on mono strategy of anaesthesia for preeclampsia in caesarean section

The aim of this study was to reveal the effects of anaesthesia strategies on maternal mean arterial pressure (MAP), heart rate, vasopressor consumption, adverse events, and neonatal resuscitation when women with preeclampsia (PE) undergo caesarean section (CS). Three major databases were searched for randomized controlled trials (RCTs) and prospective controlled studies (PCSs). Two authors independently screened, extracted, and checked eligibility and outcome data. Outcomes involved MAP, vasopressor use, maternal adverse events, APGAR scores, and neonatal resuscitation. Pooled estimates were carried out by contrast-based network meta-analysis, and pooled effect sizes were presented with 95% confidence interval (CI). Eleven RCTs and one PCS (n = 782) formed three-node network meta-analysis, and non-significant differences were observed in MAP, 5-min APGAR score, and neonatal intubation rate among the three anaesthesia strategies. General anaesthesia had significantly lower vasopressor consumption than spinal anaesthesia did (standardised mean difference =  - 1.19, 95% confidence interval [CI]: - 1.76 to - 0.63), but it had higher maternal adverse event rate (risk ratio = 2.00, 95% CI 1.16-3.47). Because no optimal anaesthesia strategy has been shown to achieve a balanced maternal and neonatal outcome, therefore a shared decision-making process may be required regarding the most suitable choice of anaesthetic strategy for individual preeclamptic mother undergoing CS. Future larger studies may need to focus on evaluating the role of vasopressors on maternal hemodynamic as well as factors affecting maternal outcomes for different anaesthetic techniques in preeclamptic women undergoing CS.

Goal-directed Fluid Therapy May Improve Hemodynamic Stability of Parturient with Hypertensive Disorders of Pregnancy Under Combined Spinal Epidural Anesthesia for Cesarean Delivery and the Well-being of Newborns

Background:

Hypotension induced by combined spinal epidural anesthesia in parturient with hypertensive disorders of pregnancy (HDP) can easily compromise blood supply to vital organs including uteroplacental perfusion and result in fetal distress. The aim of this study was to investigate whether the goal-directed fluid therapy (GDFT) with LiDCO_rapid system can improve well-being of both HDP parturient and their babies.

Methods:

Fifty-two stable HDP parturient scheduled for elective cesarean delivery were recruited. After loading with 10 ml/kg lactated Ringer's solution (LR), parturient were randomized to the GDFT and control group. In the GDFT group, individualized fluid therapy was guided by increase in stroke volume (ΔSV) provided via LiDCO_rapid system. The control group received the routine fluid therapy. The primary endpoints included maternal hypotension and the doses of vasopressors administered prior to fetal delivery. The secondary endpoints included umbilical blood gas abnormalities and neonatal adverse events.

Results:

The severity of HDP was similar between two groups. The total LR infusion (P < 0.01) and urine output (P < 0.05) were higher in the GDFT group than in the control group. Following twice fluid challenge tests, the systolic blood pressure, mean blood pressure, cardiac output and SV in the GDFT group were significantly higher, and the heart rate was lower than in the control group. The incidence of maternal hypotension and doses of phenylephrine used prior to fetal delivery were significantly higher in the control group than in the GDFT group (P < 0.01). There were no differences in the Apgar scores between two groups. In the control group, the mean values of pH in umbilical artery/vein were remarkably decreased (P < 0.05), and the incidences of neonatal hypercapnia and hypoxemia were statistically increased (P < 0.05) than in the GDFT group.

Conclusions:

Dynamic responsiveness guided fluid therapy with the LiDCO_rapid system may provide potential benefits to stable HDP parturient and their babies.

Diagnosis, evaluation, and management of the hypertensive disorders of pregnancy

OBJECTIVE

This guideline summarizes the quality of the evidence to date and provides a reasonable approach to the diagnosis, evaluation and treatment of the hypertensive disorders of pregnancy (HDP).

EVIDENCE

The literature reviewed included the previous Society of Obstetricians and Gynaecologists of Canada (SOGC) HDP guidelines from 2008 and their reference lists, and an update from 2006. Medline, Cochrane Database of Systematic Reviews (CDSR), Cochrane Central Registry of Controlled Trials (CCRCT) and Database of Abstracts and Reviews of Effects (DARE) were searched for literature published between January 2006 and March 2012. Articles were restricted to those published in French or English. Recommendations were evaluated using the criteria of the Canadian Task Force on Preventive Health Care and GRADE.

Subarachnoid block for caesarean section in severe preeclampsia

Pregnancy-induced hypertension constitutes a major cause of morbidity and mortality in developing nations and it complicates about 6–8% of pregnancies. Severe preeclampsia poses a dilemma for the anesthesiologist especially in emergency situations where caesarean deliveries are planned for uninvestigated or partially investigated parturients. This article is aimed to review the literature with regards to the type of anesthesia for such situations. A thorough search of literature was conducted on PubMed, EMBASE, and Google to retrieve the articles. Studies on parturients with severe preeclampsia, undergoing caesarean section, were included in this article. There is growing evidence to support the use of subarachnoid block in such situations when the platelet counts are >80,000 mm^-3. Better hemodynamic stability with the use of low-dose local anesthetic along with additives and better neonatal outcomes has been found with the use of subarachnoid block when compared to general anesthesia.

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.

Spinal anesthesia for lower segment Cesarean section in patients with stable eclampsia

STUDY OBJECTIVE

To report the use of spinal anesthesia in stable eclamptic patients.

DESIGN

Prospective case series.

SETTING

Emergency operating room of a metropolitan hospital.

PATIENTS

12 "stable" eclamptic parturients.

INTERVENTIONS

Subarachnoid block was instituted with hyperbaric 0.5% bupivacaine 1.7 mL with fentanyl 25 μg.

MEASUREMENTS

Intraoperative maternal hypotension, episodes of convulsion, the need to convert to general anesthesia, and Apgar scores at 1 and 5 minutes were recorded.

MAIN RESULTS

Only one of the 12 parturients had an episode of hypotension (treated by intravenous ephedrine), while no patient had a convulsion over the 48 hours after delivery. The sensory level achieved was T₅-T₆ and none of the cases was converted to general anesthesia. Median Apgar scores at 1 and 5 minutes were 8 and 9, respectively.

CONCLUSION

Spinal anesthesia avoided the known risks of general anesthesia and was not associated with any major complications.

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.

[Anesthesia and preeclampsia]

An assessment of the patient must take place as early as possible in view of anaesthesia. It is recommended to perform a clotting screen as close as possible to the performing of an epidural anaesthesia. The use of aspirin, if indicated for the prevention of PE, does not as such, constitute a contraindication to performing an epidural anaesthesia if: With regards to the minimum platelet count, the recommended cut-off value for the performing of an epidural and spinal anaesthesia are 75 & 50 x 10(9)/l respectively, only if all of the following conditions are met: It is recommended to quickly set up an epidural anaesthesia because this will improve the blood pressure as well as the utero-placenteric haemodynamics and also because this will facilitate the management in case of a caesarean section. Whereas methylergometrine (Methergin) is contraindicated in the preeclamptic patient, it is possible to use oxytocin (Syntocinion) during and after labour. Before performing a spinal anaesthesia, it is recommended to restrain the administration of crystalloids to a maximum of 1000 ml. Also the i.v. antihypertensive treatment should be reduced or interrupted until complete establishment of the anaesthetic. In case a general anaesthesia is to be performed, an assessment of the criteria for difficult intubation should be performed immediately prior to the induction. The technique employed should be a rapid sequence induction with intubation, while preventing a surge in blood pressure induced by the tracheal intubation. Difficulties to extubate should systematically be anticipated. It is possible to perform a loco-regional anaesthesia following an eclamptic crisis if the following conditions are met: In case of overlapping seizures and/or impaired consciousness, a general anaesthesia is recommended.

Maternal morbidity, mortality, and risk assessment

Maternal deaths in developed countries continue to decline and are rare. Maternal mortality statistics are essentially similar in the United States and United Kingdom. However, the situation is completely different in developing countries, where maternal mortality exceeds 0.5 million every year. This article not only assesses morbidity risks in some of the leading causes of maternal death but also highlights strategies to minimize the risks and to prevent maternal morbidity and mortality.

Contraindications to regional anaesthesia in obstetrics: a survey of German practice

BACKGROUND

We assessed current practice regarding indications and contraindications to regional analgesia and anaesthesia for labour and delivery in Germany.

METHODS

Questionnaires were mailed to the directors of 918 German departments of anaesthesiology.

RESULTS

A total of 397 completed replies were received representing 41.3% of all deliveries in Germany. More than half of the respondents never perform spinal or epidural anaesthesia when the platelet count falls below 65x10(9)/L. Preeclampsia, which was not graded for severity, was considered an absolute contraindication to regional block by 15% and placenta praevia by 30% of respondents. If a woman had taken aspirin three days before, the numbers of respondents considering epidural anaesthesia contraindicated (40.2%) were nearly double those considering spinal anaesthesia contraindicated (21.7%) (P<0.001). For a platelet count of 79x10(9)/L, epidural anaesthesia was thought to be contraindicated by 37% and spinal anaesthesia by 22.2% (P=0.001). In departments with <500 deliveries/year, reluctance to use regional blockade was more pronounced than in departments with >1000 deliveries/year.

CONCLUSION

Clinical practice varies considerably in Germany. Concerns regarding the use of regional blockade were more prevalent in hospitals with small delivery units. Indications and contraindications are not consistent in Germany and some recommendations or guidelines are needed.

Anaesthesia for caesarean section in a patient with systemic amyloidosis secondary to familial Mediterranean fever

The anaesthetic management of a 33-year-old primigravid woman at 29 + 5 weeks' gestation with familial Mediterranean fever (FMF), secondary amyloidosis, renal allograft with deteriorating renal function and cardiac impairment for emergency caesarean section is described. Pathophysiology and management options are discussed. Cautious induction of epidural anaesthesia together with continuous invasive monitoring produced a good outcome for mother and baby.

Anaesthetic dilemma: spinal anaesthesia in an eclamptic patient with mild thrombocytopenia and an “impossible” airway

We present our anaesthetic management of a 27-year-old woman with antepartum eclampsia, mild thrombocytopenia, difficult airway and clinical evidence of impending upper airway obstruction. She required urgent delivery by caesarean section, which was conducted uneventfully under spinal anaesthesia. We discuss the management conundrums presented by this case and why we chose spinal anaesthesia over other anaesthetic options.

Regional Anaesthesia in Pre-eclampsia

Pre-eclampsia is a multisystemic disorder that is characterised by endothelial cell dysfunction as a consequence of abnormal genetic and immunological mechanisms. Despite active research for years, the exact aetiology of this potentially fatal disorder remains unknown. Although understanding of the pathophysiology of pre-eclampsia has improved, management has not changed significantly over the years. Anaesthetic management of these patients remains a challenge. Although general anaesthesia can be used safely in pre-eclamptic women, it is fraught with greater maternal morbidity and mortality. Currently, the safety of regional anaesthesia techniques is well established and they can provide better obstetrical outcome when chosen properly. Thus, regional anaesthesia is extensively used for the management of pain and labour in women with pre-eclampsia. This article highlights the advantages and disadvantages of regional anaesthetic techniques including epidural, spinal and combined spinal-epidural analgesia, used as a part of the management of pre-eclampsia. The problems associated with general anaesthesia and controversies in relation to obstetric regional anaesthesia are discussed.

Obstetric emergencies

Obstetric hemorrhage is still a significant cause of maternal morbidity and mortality. Prevention, early recognition, and prompt intervention are the keys to minimizing complications. Resuscitation can be inadequate because of under-estimation of blood loss and misleading maternal response. A young woman may maintain a normal blood pressure until sudden and catastrophic decompensation occurs. All members of the obstetric team should know how to manage hemorrhage because timing is of the essence. Good communication with the blood bank ensures timely release of appropriate blood products. A well-coordinated team is one of the most important elements in the care of a compromised fetus. If fetal anoxia is presumed, there is less than 10 minutes to permanent fetal brain damage. Antepartum anesthesia consultation should be encouraged in parturients with medical problems.

Pre-eclampsia: fluids, drugs, and anesthetic management

Severe pre-eclampsia is a complex disease, which taxes the expertise of even the most experienced obstetric anesthesiologist. The treatment should focus on stabilization of blood pressure, optimization of fluid status, and prevention of convulsions. Neuraxial blocks for labor and delivery offer many benefits to the mother and her infant. For cesarean section, there is unequivocal evidence of superiority of neuraxial anesthesia over general anesthesia. If general anesthesia is needed, careful preanesthetic preparation and meticulous airway management is essential. The successful and safe peripartum management of the pre-eclamptic patient and her infant is a team effort among the anesthesiologist, obstetrician, and neonatologist.

Retrospective review of spinal versus epidural anaesthesia for caesarean section in preeclamptic patients

A 5-year retrospective survey of anaesthesia for caesarean section for mild/moderate and severe preeclampsia was performed, covering the period between 1 January 1996 and 31 December 2000. One hundred and twenty-one cases of non-labouring preeclamptic patients receiving spinal or epidural anaesthesia for caesarean section were included for analysis. Comparisons were made of the lowest blood pressures recorded before induction of anaesthesia, during the period from induction to delivery and the period from delivery to the end of operation. The decreases in blood pressure were similar after spinal and epidural anaesthesia. The use of intravenous fluids and ephedrine were also comparable in the two anaesthetic groups. There was no difference in maternal or neonatal outcome. Our result supports the use of spinal anaesthesia in preeclamptic women.

Maternal benefit of corticosteroid therapy in patients with HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome: impact on the rate of regional anesthesia

OBJECTIVE

Our purpose was to assess the impact of glucocorticoid administration on the rate of regional anesthesia in women with hemolysis, elevated liver enzymes, and low platelet count (HELLP) syndrome.

STUDY DESIGN

Maternal records of pregnancies with HELLP syndrome managed between April 1994 and December 1999 were analyzed retrospectively.

RESULTS

Sixty-nine patients were identified with antepartum HELLP syndrome and 46 (66%) received glucocorticoids. The presence of thrombocytopenia at admission and the interval from presentation to delivery was evaluated to assess the impact of glucocorticoid use. In the 37 women who had platelet counts of <90,000/mm3, 0 in the untreated group (0 of 11) versus 42% in the steroid group (11 of 26) received regional anesthetic, P =.015. Furthermore, the rate of regional anesthesia increased from 0 in the untreated group delivered within 24 hours (n = 10) to 57% (8 of 14) in the glucocorticoid group, in which women attained a 24-hour latency from presentation to delivery, P =.006. The need for general anesthesia also decreased significantly in treated women who attained a 24-hour latency compared to untreated women who did not, 100% (n = 7) versus 22% (n = 9), P =.003.

CONCLUSIONS

Administration of glucocorticoids increases the use of regional anesthesia in women with antepartum HELLP syndrome who have thrombocytopenia, particularly in those who achieve a latency of 24 hours before delivery.

Anaesthetic management of Caesarean section in an elderly parturient with pre-eclampsia

The number of women over 40 years of age becoming pregnant has increased over recent years. They suffer a high incidence of hypertensive complications, and require more frequent operative interventions. We present a case report of a 51-year-old woman having a Caesarean section for a twin pregnancy complicated by pre-eclampsia. We discuss the effects of age on pregnancy and the implications for anaesthetic management.

Spinal haematoma following epidural anaesthesia in a patient with eclampsia

A patient with a twin pregnancy required a Caesarean section for severe pre-eclampsia. Her platelet count was 71 x 10(9).l-1. Epidural anaesthesia was performed after platelet transfusion. A spinal epidural haematoma was diagnosed postoperatively. A generalised tonic-clonic seizure sparing the lower limbs enabled early diagnosis to be made. The patient recovered with no permanent neurological damage after laminectomy and clot removal. The risks and benefits of regional techniques require careful consideration, and postoperative monitoring for recovery of neural blockade is essential.

The stress response of critical illness

The integrated stress response to tissue trauma is crucial for the maintenance of homeostasis. An exaggerated or prolonged response may be detrimental in compromised patients. Knowledge of the involved afferent pathways will suggest therapeutic interventions that may modulate the intensity of the stress response. Described are these concepts as they relate to perioperative medicine.

Effects of regional anesthesia on perioperative outcome

To provide an overview of current knowledge, this article reviews experimental and clinical data from investigations examining effects of regional anesthesia on perioperative morbidity in specific physiologic systems. The issues of morbidity and mortality following general and regional anesthesia are addressed, as are the development of perioperative thromboembolism and blood loss, which are known to be increased during general anesthesia. Finally, the effects of regional anesthesia on the vascular system, the perioperative stress response, and the pulmonary function are discussed.