Are combined spinal-epidural catheters reliable?

A randomized comparison of epidural, dural puncture epidural, and combined spinal-epidural without intrathecal opioids for labor analgesia

Background and Aims

Dural puncture epidural (DPE) has been shown to improve labor analgesia over epidural (EPL), with fewer side effects than a combined spinal-epidural (CSE). However, there is some debate regarding the superiority of DPE over EPL and CSE. Therefore, we aimed to compare the effects of EPL, DPE, and CSE without intrathecal opioids on the epidural local anesthetic (LA) consumption and occurrence of side effects in early labor.

Material and Methods

We randomly assigned parturient to one of the 3 groups; EPL, DPE, or CSE. EPL and DPE groups received a 10 mL loading dose of 0.1% bupivacaine with fentanyl 2 μg/mL. CSE group received intrathecal 2.5 mg bupivacaine (without opioids). Labor analgesia was maintained in all patients via patient-controlled epidural analgesia (PCEA). The primary outcome was the mean hourly consumption of epidural LA.

Results

The mean hourly consumption of epidural LA anesthetic was significantly lower in CSE (9.55 mL), compared with the EPL (11 mL), and DPE (10.5 mL), P < 0.01; but no significant difference was seen between EPL and DPE. Compared with EPL and DPE, CSE achieved faster time to complete analgesia defined as a numeric rating pain scale (NRPS) ≤1 and sensory block, lower NRPS in the first hour and higher frequencies of complete analgesia. There were no differences between groups in terms of physician top-up boluses, the occurrence of side-effects, mode of delivery, Apgar scores, and maternal satisfaction.

Conclusion

Compared with EPL and DPE, CSE without intrathecal opioids, had a less epidural LA consumption, faster onset of analgesia, with no difference in the incidence of side effects.

Trial Registration

This study was registered at www.clinicaltrials.gov (NCT03980951).

Pain management during labor and vaginal birth

Neuraxial analgesia provides excellent pain relief in labor. Optimizing initiation and maintenance of neuraxial labor analgesia requires different strategies. Combined spinal-epidurals or dural puncture epidurals may offer advantages over traditional epidurals. Ultrasound is useful in certain patients. Maintenance of analgesia is best achieved with a background regimen (either programmed intermittent boluses or a continuous epidural infusion) supplemented with patient-controlled epidural analgesia and using dilute local anesthetics combined with opioids such as fentanyl. Nitrous oxide and systemic opioids are also used for pain relief. Nitrous oxide may improve satisfaction despite variable effects on pain. Systemic opioids can be administered by healthcare providers or using patient-controlled analgesia. Appropriate choice of drug should take into account the stage and progression of labor, local safety protocols, and maternal and fetal/neonatal side effects. Pain in labor is complex, and women should fully participate in the decision-making process before any one modality is selected.

Development and validation of a predictive risk factor model for epidural re-siting in women undergoing labour epidural analgesia: a retrospective cohort study

Background

Epidural catheter re-siting in parturients receiving labour epidural analgesia is distressing to the parturient and places them at increased complications from a repeat procedure. The aim of this study was to develop and validate a clinical risk factor model to predict the incidence of epidural catheter re-siting in labour analgesia.

Methods

The data from parturients that received labour epidural analgesia in our centre during 2014–2015 was used to develop a predictive model for epidural catheter re-siting during labour analgesia. Multivariate logistic regression analysis was used to identify factors that were predictive of epidural catheter re-siting. The forward, backward and stepwise variable selection methods were applied to build a predictive model, which was internally validated. The final multivariate model was externally validated with the data collected from 10,170 parturients during 2012–2013 in our centre.

Results

Ninety-three (0.88%) parturients in 2014–2015 required re-siting of their epidural catheter. The training data set included 7439 paturients in 2014–2015. A higher incidence of breakthrough pain (OR = 4.42), increasing age (OR = 1.07), an increased pain score post-epidural catheter insertion (OR = 1.35) and problems such as inability to obtain cerebrospinal fluid in combined spinal epidural technique (OR = 2.06) and venous puncture (OR = 1.70) were found to be significantly predictive of epidural catheter re-siting, while spontaneous onset of labour (OR = 0.31) was found to be protective. The predictive model was validated internally on a further 3189 paturients from the data of 2014–2015 and externally on 10,170 paturients from the data of 2012–2013. Predictive accuracy of the model based on C-statistic were 0.89 (0.86, 0.93) and 0.92 (0.88, 0.97) for training and internal validation data respectively. Similarly, predictive accuracy in terms of C-statistic was 0.89 (0.86, 0.92) based on 2012–2013 data.

Conclusion

Our predictive model of epidural re-siting in parturients receiving labour epidural analgesia could provide timely identification of high-risk paturients required epidural re-siting.

Combined Spinal Epidural Technique for Labor Analgesia Does Not Delay Recognition of Epidural Catheter Failures

Background

It is unclear whether recognition of epidural catheter failures is delayed with combined spinal epidural technique (CSE) compared to traditional epidural technique (EPID) when used for labor analgesia. The authors hypothesized that recognition of failed catheters is not delayed by CSE.

Methods

Anesthetic, obstetric, and quality assurance records from 2,395 labor neuraxial procedures (1,440 CSE and 955 EPID) performed at Forsyth Medical Center (Winston-Salem, North Carolina) between June 30 and December 31, 2012, were retrospectively analyzed. The primary outcome was catheter survival (failure-free) time during labor analgesia. A proportional hazards model with the counting method was used to assess relationships between the techniques and survival (failure-free) time of catheters, while controlling for subjects’ body mass index and providers’ level of training in the final best-fit multivariable regression model.

Results

Cumulative incidence of epidural catheter failures was 6.6% for CSE and 11.6% for EPID (P = 0.001). In the multivariable regression model, catheters placed with CSE versus epidural were less likely to fail (hazard ratio, 0.58; 95% CI, 0.43 to 0.79; P = 0.0002) for labor analgesia. Among the catheters that failed, there was no overall difference in failure time course between the techniques (hazard ratio, 1.17; 95% CI, 0.89 to 1.54; P = 0.26) even though more failed catheters with CSE (48.4%) than with EPID (30.6%) were recognized within the first 30 min of placement (P = 0.009).

Conclusions

In this cohort, CSE has a significantly lower risk of overall epidural catheter failures than EPID and does not delay recognition of epidural catheter failures. Choice of CSE versus EPID should be based on overall risk of failure, efficacy, and side effects.

Combined spinal-epidural versus epidural analgesia for labor and delivery

The rapid onset of analgesia and improved mobility with combined spinal-epidural (CSE) techniques has been associated with a higher degree of maternal satisfaction compared with conventional epidural analgesia. However, controversy exists in that initiation of labor analgesia with a CSE may be associated with an increased risk for nonreassuring fetal status (ie, fetal bradycardia) and a subsequent need for emergent cesarean delivery. Overall, both epidural and CSE techniques possess unique risk/benefit profiles, and the decision to use one technique rather than the other should be determined based on individual patient and clinical circumstances.

Anesthesia considerations in the obese gravida

Obesity is associated with serious morbidity during pregnancy, and obese women also are at a high risk of developing complications during labor, leading to an increased risk for instrumental and Cesarean deliveries. The engagement of the obstetrical anesthetist in the management of this group of high-risk patients should be performed antenatally so that an appropriate management strategy can be planned in advance to prevent an adverse outcome. Good communication between all care providers is essential. The obese patient in labor should be encouraged to have a functioning epidural catheter placed early in labor. Apart from providing analgesia and alleviating physiological derangements during labor, the presence of a functioning epidural catheter can also be used to induce anesthesia quickly in the event of an emergency cesarean section, thus avoiding a general anesthesia, which has exceedingly high risks in the obese parturient. Successful management of the obese patient necessitates a comprehensive strategy that encompasses a multidisciplinary and holistic approach from all care-providers.

Morbidly obese parturient: Challenges for the anaesthesiologist, including managing the difficult airway in obstetrics. What is new?

The purpose of this article is to review the fundamental aspects of obesity, pregnancy and a combination of both. The scientific aim is to understand the physiological changes, pathological clinical presentations and application of technical skills and pharmacological knowledge on this unique clinical condition. The goal of this presentation is to define the difficult airway, highlight the main reasons for difficult or failed intubation and propose a practical approach to management Throughout the review, an important component is the necessity for team work between the anaesthesiologist and the obstetrician. Certain protocols are recommended to meet the anaesthetic challenges and finally concluding with “what is new?” in obstetric anaesthesia.

Cesarean delivery in the obese parturient: anesthetic considerations

Obesity is a worldwide health problem and its prevalence is reaching epidemic proportions. As obesity does not spare women of childbearing age, obstetric anesthesiologists will increasingly be exposed to the challenges of anesthesia in this population. The purpose of this article is to give the reader a thorough understanding of the anesthetic implications of obesity relating to cesarean deliveries. Obesity is associated with hypertension, diabetes, obstructive sleep apnea and other comorbidities. It increases the risk of cesarean delivery, postpartum wound infections and deep venous thromboembolism. Obese parturients are prone to anesthetic complications such as aspiration of gastric contents, difficult monitoring, positioning, airway management and challenging neuraxial techniques. A thorough precesarean delivery preparation should include an evaluation by an anesthesiologist for women with a BMI over 40 kg/m² and institution of an antacid prophylaxis protocol, thromboprophylaxis and antibiotic prophylaxis. Regional anesthesia should ideally be used in all obese parturients unless contraindicated. The goals of postpartum care include efficacious analgesia, physiotherapy and early mobilization. Monitoring and vigilance in an intensive care unit or step-down units should be considered for morbidly obese women.

Progress in analgesia for labor: focus on neuraxial blocks

Neuraxial analgesia is widely accepted as the most effective and the least depressant method of providing pain relief in labor. Over the last several decades neuraxial labor analgesia techniques and medications have progressed to the point now where they provide high quality pain relief with minimal side effects to both the mother and the fetus while maximizing the maternal autonomy possible for the parturient receiving neuraxial analgesia. The introduction of the combined spinal epidural technique for labor has allowed for the rapid onset of analgesia with minimal motor blockade, therefore allowing the comfortable parturient to ambulate. Patient-controlled epidural analgesia techniques have evolved to allow for more flexible analgesia that is tailored to the individual needs of the parturient and effective throughout the different phases of labor. Computer integrated systems have been studied to provide seamless analgesia from induction of neuraxial block to delivery. New adjuvant drugs that improve the effectiveness of neuraxial labor analgesia while decreasing the side effects that may occur due to high dose of a single drug are likely to be added to future labor analgesia practice. Bupivacaine still remains a popular choice of local anesthetic for labor analgesia. New local anesthetics with less cardiotoxicity have been introduced, but their cost effectiveness in the current labor analgesia practice has been questioned.

Modern neuraxial labor analgesia: options for initiation, maintenance and drug selection

In the present review we outline the state-of-the-art of neuraxial analgesia. As neuraxial analgesia remains the gold standar of analgesia during labor, we review the most recent literature on this topic. The neuraxial analgesia techniques, types of administration, drugs, adjuvants, and adverse effects are investigated from the references. Most authors would agree that central neuraxial analgesia is the best form to manage labor pain. When neuraxial analgesia is administered to the parturient in labor, different management choices must be made by the anesthetist: how will we initiate analgesia, how will analgesia be maintained, which local anesthetic will we use for neuraxial analgesia and which adjuvant drugs will we combine? The present manuscript tries to review the literature to answer these questions.

[Failure of extension of epidural analgesia to anesthesia for emergency cesarean section]

Epidural analgesia provides effective control of labor pain and allows emergency cesarean section to be performed without recourse to general anesthesia. This technique is subject to failure, however. We sought to determine the incidence of failure of extension of epidural analgesia for labor to epidural anesthesia for emergency cesarean section. We also analyzed possible risk factors for failure. A 2-month observational study was carried out in a tertiary-care university hospital in patients who had an epidural catheter inserted for labor analgesia and who later underwent emergency cesarean section. Epidural catheter failure was defined if additional analgesia was required during surgery or if general anesthesia was required. Data were gathered on possible risk factors, such as obesity, difficult epidural puncture, leakage of blood on insertion, history of cesarean delivery, need for rescue analgesia, and level of satisfaction with analgesia during dilation. In total, 134 emergency cesareans were performed in women carrying an epidural catheter. The catheter failed to administer the anesthetic in 18 patients (13.4%). General anesthesia was required in 9 cases (6.7%). Difficult insertion (more than 2 attempts) was associated with a higher failure rate (P=.064). The relative risk of epidural catheter failure was 2.86-fold higher when rescue analgesia was needed during delivery than in cases when no supplement was required (P=.021). Receiving adequate analgesia during labor seems to be a protective factor (80%) against anesthetic catheter failure during cesarean section (P=.01). We conclude that high demand for rescue analgesia and signs of inadequate analgesia during labor should warn of epidural catheter failure if extension to anesthesia becomes necessary for a cesarean delivery.

Failure of augmentation of labor epidural analgesia for intrapartum cesarean delivery: a retrospective review

In this study, we aimed to identify the incidence and predictive factors associated with failed labor epidural augmentation for cesarean delivery. Data of parturients, who had received neuraxial labor analgesia and who subsequently required intrapartum cesarean delivery during an 18-mo period, were retrospectively studied. Predictors associated with failure of extension of epidural analgesia in the presence of adequate time for onset of epidural anesthesia were identified by univariate logistic regression. Of the 1025 parturients, 1.7% had failed epidural extension. Predictors of failed epidural anesthesia included initiation of labor analgesia with plain epidural technique (compared to combined spinal-epidural) (P = 0.001), >or=2 episodes of breakthrough pain during labor (P < 0.001) and prolonged duration of neuraxial labor analgesia (P = 0.02).

Obstetric anesthesia for the obese and morbidly obese patient: an ounce of prevention is worth more than a pound of treatment

BACKGROUND

The incidence of obesity has been dramatically increasing across the globe. Anesthesiologists, are increasingly faced with the care for these patients. Obesity in the pregnant woman is associated with a broad spectrum of problems, including dramatically increased risk for cesarean delivery, diabetes, hypertension and pre-eclampsia. A thorough understanding of the physiology, associated conditions and morbidity, available options for anesthesia and possible complications is therefore important for today's anesthesiologist.

METHODS

This is a personal review in which different aspects of obesity in the pregnant woman, that are relevant to the anesthesiologist, are discussed. An overview of maternal and fetal morbidity and physiologic changes associated with pregnancy and obesity is provided and different options for labor analgesia, the anesthetic management for cesarean delivery and potential post-partum complications are discussed in detail.

RESULTS AND CONCLUSION

The anesthetic management of the morbidly obese parturient is associated with special hazards. The risk for difficult or failed intubation is exceedingly high. The early placement of an epidural or intrathecal catheter may overcome the need for general anesthesia, however, the high initial failure rate necessitates critical block assessment and catheter replacement when indicated.

Combined Spinal Epidural Causes Higher Level of Block than Equivalent Single-Shot Spinal Anesthesia in Elective Cesarean Patients

Combined spinal epidural (CSE) is an established technique for lower segment cesarean delivery. In this study we tested the hypothesis that the spinal block from a CSE technique results in a more extensive spread of local anesthetic in the subarachnoid space than the single-shot spinal (SSS) technique. We recruited 30 ASA physical status I parturients admitted for elective lower segment cesarean delivery into our randomized, controlled, double-blind study. All patients intrathecally received 2 mL of 0.5% hyperbaric bupivacaine. The patients were randomized into one of the two groups using sealed opaque envelopes. Group S (n = 15) received a SSS technique. Group CS (n = 15) received a CSE technique using loss of resistance to 2 mL of air, but the epidural catheter was not inserted after the intrathecal drug administration. The maximal sensory block achieved in group CS was statistically higher than that in Group S (median C6 interquartile range, C5 to C8 versus median T3, T2 to T4, P < 0.001). Time taken to reach maximal sensory block was significantly longer in group CS. There were no differences in the time taken for the block to recede to T10, hemodynamic profile, or side effects. In conclusion, the CSE technique without placing an epidural catheter or administering epidural medication resulted in a significantly higher level of sensory block when compared with the SSS technique when the same dose of local anesthetic was given intrathecally.

Epidural catheter function during labor predicts anesthetic efficacy for subsequent cesarean delivery

One of the benefits of labor epidural analgesia is that the catheter can be used to initiate a surgical block should the need for cesarean delivery arise. However, sometimes it is not possible to obtain adequate surgical anesthesia via a previously placed labor epidural catheter and it is unknown what factors are associated with this failure. We retrospectively investigated the incidence of failure to convert a labor epidural to a successful surgical block in our institution over a period of one year and determined the factors associated with this failure. There were 246 cases in which a patient had an epidural catheter placed for labor and then had a cesarean delivery. Of these 246 cases, 220 developed surgical anesthesia using the catheter. In six cases the anesthesiologist did not attempt to use the epidural catheter for the cesarean delivery. In 20 cases (classified as failed blocks), the catheter was injected, but another method of anesthesia was then used. Factors associated with failure of the epidural block were an increased requirement for supplemental local anesthetic boluses during labor in order to provide adequate analgesia and that the attending anesthesiologist for the cesarean delivery was not a specialist in obstetric anesthesia. Most epidural catheters placed for labor can be used to induce a surgical block. When significantly more local anesthetic than usual is required to maintain analgesia during labor, however, the epidural catheter may not be functioning properly and consideration should be given to replacing it.

Anaesthesia for Caesarean section: a survey in a UK region from 1992 to 2002

Data are presented for anaesthesia for Caesarean section (CS) in the South-west Thames region of the UK. The CS rate rose from 12.7% in 1987 to 24.2% in 2002. The rate of increase shows no sign of slowing. The rate of regional anaesthesia (RA) for elective CS rose from 69.4% in 1992 to 94.9% in 2002, when spinal anaesthesia was used for 86.6% of cases. This may limit the opportunities to teach other anaesthetic techniques. The rate of RA for emergency CS rose from 49.3% in 1992 to 86.7% in 2002. There is an unacceptable rate of failure of RA for both elective and emergency CS, 1.3% of RAs for elective CS and 4.9% of RAs for emergency CS were converted to general anaesthesia.

Newer techniques of labor analgesia

In maternity units in which central neuraxial techniques are frequently used, newer methods of epidural drug delivery (continuous infusion, patient-controlled) are well established and combined spinal-epidural analgesia is commonly used. Continuous spinal analgesia has reemerged as a useful approach after accidental dural puncture. Lumbar sympathetic block has been revisited and the safety of paracervical nerve block improved. The analgesic properties of systemic opioid in labor are poor, but PCIA at least has psychological benefits and allows rapid drug titration. PCIA is again under investigation because of the potent antinociceptive effects of the short-acting mu-opioid agonist, remifentanil. The premixing of nitrous oxide and a subanesthetic concentration of volatile anesthetic for patient-controlled administration has been tested under control of midwifery staff and without direct medical supervision.

Post dural puncture headache following combined spinal epidural or epidural anaesthesia in obstetric patients

A retrospective review of obstetric anaesthesia charts was performed for all parturients receiving regional anaesthesia over a 22-month period. The incidence of headache, post dural puncture headache (PDPH) and various other complications of regional anaesthesia that had been prospectively assessed were noted, as was the anaesthetic technique used (epidural or combined spinal epidural (CSE)). PDPH was rare (0.44%) and occurred with similar frequency in those managed with either epidural or CSE anaesthesia or analgesia. The pencil-point spinal needle gauge (27 or 29) did not influence the incidence of PDPH. Following a CSE technique, the epidural catheter more reliably produced effective analgesia/anaesthesia as compared with a standard epidural technique (1.49% versus 3.18% incidence of replaced catheters respectively). We conclude, based on the results of this retrospective review, that CSE is acceptable with respect to the occurrence of PDPH and that it is possible it is advantageous in relation to the correct placement of the epidural catheter