Does Labor Analgesia Affect Labor Outcome? Presented to you by: Allen Miraflor, T4

“The First Operation with Ether, Robert Hinckley

1847: James Simpson administered chloroform to a woman in labor for childbirth. It will be necessary to ascertain anesthesia’s precise effect, both upon the action of the uterus and on the assistant abdominal muscles; its influence, if any, upon the child; whether it has a tendency to hemorrhage or other complications Introduction

Sir James Simpson, January 1847

The modern debate has centered on several main issues Does regional anesthesia for labor affect: –The length of labor –Increased risk of Cesarean delivery –Does timing of initiation of epidural analgesia play a role? Introduction

The Successive Stages of Labor Quick look at Epidurals & Combined Spinal-Epidurals Vital Background Information

The Successive Stages of Labor: Stage 1 Ranges from onset of labor until complete dilation of the cervix has occurred. Further divided into the latent and active phases

The Successive Stages of Labor: Latent Phase of Stage 1 Onset of labor until 3-4cm of dilation

The Successive Stages of Labor: Active Phase of Stage 1 Follows latent phase Extends until complete cervical dilation Includes the period of time when the slope of cervical change against time increases Stage 2 encompasses complete cervical dilation through delivery of infant

Epidural Analgesia vs. Combined Spinal Epidural Anesthesia Catheter placed in lumbar epidural space Ligaments characterized by a high degree of resistance Epidural recognized by sudden loss of resistance as needle enters epidural space Catheter advanced into the space

Epidural Analgesia vs. Combined Spinal Epidural Anesthesia Lumbar epidural space identified Thin spinal needle introduced through epidural needle into subarachnoid space. Correct placement confirmed by flow of CSF Bolus of meds injected into subarachnoid space Needle removed and a catheter is advanced into epidural space

Epidural Analgesia vs. Combined Spinal Epidurals: Advantages Ability to achieve segmental bands of analgesia (T10-L1) during first stage of labor when total anesthesia is not required Ability to extend the block to include the S2-S4 segments Extension of sensory anesthesia to T4 for cesarean delivery if necessary Faster onset of analgesia than conventional epidural analgesia Helpful in certain patient populations: Relief for post-op pain Long labor Additional procedures after delivery such as a tubal ligation

Current Opinion on Labor Analgesia Optimal timing has been a controversial issue Before 2002, clinical guidelines recommended waiting until cervical dilation reached at least 4-5cm Significant studies arose in the early 2000s In June 2006,the American College of Obstetricians and Gynecologists changed their recommendation. The NIH instituted guidelines which now suggest that : “women in labor who desire regional anesthesia should not be denied it, including women in severe pain in the latent first stage of labor”

Important Studies to Examine Exploring the Literature

Exploring the Literature: Wong et al. (Feb 2005)

Randomized trial of 750 nulliparous women who were in spontaneous labor or had spontaneous rupture of membranes All patients had a cervical dilation of less than 4.0cm. Women were randomly assigned to receive intrathecal fentanyl or systemic hydromorphone at the first request for analgesia Epidural anesthesia was initiated in the intrathecal group at the second request and in the systemic group when cervical dilation reached 4.0cm or greater. Wong et al. 2005

Rate of Cesarean delivery not significantly different between groups Median time from analgesia initiation to complete dilatation was significantly shorter after intrathecal analgesia, as was the time to vaginal delivery Pain scores after first intervention were significantly lower after intrathecal analgesia than after systemic Conclusion: “neuraxial analgesia in early labor did not increase the rate of Cesarean delivery, and it provided better analgesia and resulted in a shorter duration of labor than systemic analgesia” Wong et al. 2005

How about in patients undergoing induction of labor? Exploring the Literature

Nulliparas undergoing induction of labor who requested analgesia when cervical dilation was less than 4cm participated in the study Patients were randomized to neuraxial or systemic opioid analgesia at the first analgesia request Primary outcome was the rate of cesarean delivery Findings: Rate of cesarean delivery was not different between groups (neuraxial 32.7% comapred with systemic 31.5%) Conclusion: “Early-labor neuraxial analgesia does not increase the cesarean delivery rate compared with late epidural analgesia in nulliparas undergoing induction of labor” Exploring the Literature: Wong et al. 2009

Exploring the Literature: Wang et al. (Anesthesiology 2009)

Single institution 5- year randomized controlled trial of 12,793 parturients Randomized to an early epidural (cervical dilation of at least 1.0 cm) or delayed epidural (cervical dilation at least 4.0cm) A 15ml epidural analgesic mixture of 0.125% ropivicaine plus 0.3 ug/ml sufentanil was given in a single bolus, followed by a patient controlled pump with a 10-ml bolus without background infusion Primary outcome was the rate of Cesarean delivery Exploring the Literature: Wang et al. (Anesthesiology 2009)

Findings: –Duration of labor from analgesia request to vaginal delivery was almost equal in both groups –No statistically significant difference in the rate of C-section was observed between the two groups Conclusion: “epidural analgesia in the latent phase of labor at cervical dilation of 1cm or more does not prolong the progression of labor and does not increase the rate of Cesarean delivery in nulliparous women…” Exploring the Literature: Wang et al. (Anesthesiology 2009)

Early request for analgesia may be markers for other risk factors for cesarean delivery –Fetal macrosomia –Labor dystocia –Fetal malposition Breech presentation Face / Brow presentation What Can Explain the Absence of an Association Between Epidural Analgesia and an Increase C-Section Delivery Rate?

 History Short on OB Anesthesia  Successive Stages of Labor  Explored Different Types of OB Analgesia  Reviewed Literature  Possible explanation of the absence of an association with OB anesthesia and increased C-section delivery rate What We Covered So Far:

Earlier administration of epidural analgesia or CSE does not cause longer labor or an increase in operative delivery In the absence of a contraindication, women should be offered an epidural whenever labor pain is intensive enough to elicit a request for analgesia Appreciation of indirect effects of the practice style of obstetricians or the decision-making process of patients may further our understanding of the possible effects of epidural analgesia. In Conclusion

References Segal S. (2002). Epidural analgesia and the progress and outcome of labor and delivery. Int Anesthesiol Clin. 40(4): Segal S. (2009). Does labor analgesia affect labor outcome? Evidence-Based Practice of Anesthesiology, Second Edition. pp Wang F, Shen X, Guo X, Peng Y, Gu X. (2009). Epidural analgesia in the latent phase of labor and the risk of Cesarean delivery. Anesthesiology. 111: Wong C, McCarthy R, Sullivan J, Scavone B, Gerber S, Yaghmour E. (2009). Early compared with late neuraxial analgesia in nulliparous labor induction. Obstetrics and Gynecology. 113(5): Wong C, Scabone B, Peaceman A, McCarthy R, Sullivan J, Diaz N, Yaghmour E, Marcus R, Sherwani S, Sproviero M, Yilmaz M, Patel R, Robles C, Grouper S. (2005). The risk of cesarean delivery with neuraxial analgesia given early versus late in labor. New England Journal of Medicine. 352(7):

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