24h-payday

Epidural Analgesia—a delicate dance between its positive role and unwanted side effects (Part Two)

This post is the second in a series by Dr. Michael Klein.  You can find the first installment of this series here.

Research into the consequences of epidural use
Whether the benefits of epidural analgesia outweigh the potential risks has been the subject of many controversies over recent decades. In my department we have studied these controversies extensively. On a regular basis we looked at our own performance in caring for laboring women. The Department of Family Practice at British Columbia Women’s Hospital in Canada (familiarly known as ‘BC Women’s)’is made up of over 100 family doctors, who all attend births. BC Women’s is the largest maternity hospital in Canada, with more than 7,000 births per year, and family doctors are responsible for almost half of these births, despite the hospital also being the tertiary care referral centre for the province. This makes us the largest group of family doctors attending births in Canada.

We knew from the literature that epidural analgesia use early in labour, before the fetus was well down in the pelvis, could cause malpositioning (occiput posterior or transverse) (7) due to extension of the fetal head. If the fetal head is extended, it cannot rotate or descend. We found that physicians who ordered epidurals frequently and early in labour had more patients with malpositioned fetuses.(8) They also had more patients who received greater amounts of synthetic oxytocin augmentation of labour. They had fewer spontaneous births and more cesarean sections than those in the department who used epidurals less often. Also, surprisingly, high epidural rates were associated with increased numbers of newborns with low 5-minute Apgar scores and more babies admitted to the newborn intensive care unit.

We found that physicians with mean epidural rates under 40% for women having their first baby, had cesarean section rates of about 10%. In contrast, those family doctors with mean epidural rates of 71-100% had cesarean section rates of 23.4%, the others having rates between the two extremes. The women cared for by the three groups were similar. Thus it appeared that only physician practice difference could have accounted for such large differences in outcome. Interestingly, the caesarean rates of women who were having their second or more births were unaffected by the way in which their doctors prescribed epidurals.

Our departmental experience was similar to results from an observational study in which we compared outcomes at a nearby community hospital with our tertiary care centre. (9) In the community care setting, mean epidural analgesia rates were 15.4% compared with 67.2% in the tertiary care center, for comparable women. The odds of having a cesarean section were 3.4 times greater at the tertiary care centre than in the community hospital. The increased and earlier use of epidural analgesia in the tertiary care setting almost completely explained this difference. The community hospital setting encouraged the use of other non-epidural pain coping techniques, resulting in later epidural placements compared to those in the tertiary hospital setting. We were also interested to note that those physicians who ordered epidurals less often actually spent more time with their patients, even though on average their patients spent less time in hospital. The time they spent with their patients involved more intimate, hands-on, supportive care.

It is because of these studies that we had trouble accepting the results of the 2004 Cochrane meta-analysis that concluded that epidural analgesia did not raise the cesarean section rate.(10) This conclusion was the same in the most recent Cochrane meta-analysis,(11) this new one deeply flawed by the inclusion of many studies of women who suffered from complex medical conditions, and many studies that randomized women late, particularly since conventional practice is to use epidurals earlier. Clearly, any meta-analysis is only as good as the individual studies included—illustrating the well-known principle: garbage in, garbage out.

Epidural Analgesia has transformed birth:
In fact, it appeared to us that the increasing use of epidural analgesia was transforming birth. This observation was confirmed by a report from the Canadian Institute for Hospital Information, which indicated that 4 in 5 Canadian women received one or more major obstetrical interventions, with epidurals high on the list at rates of 40-50% of births in various Canadian settings. (12)

We decided to look more closely at earlier Cochrane (10) individual studies that made up the meta-analysis addressing the effect of epidural analgesia on c-section rates. These studies revealed that, epidural analgesia increased the length of the first stage of labour by 4.3 hours. Similarly, the second stage of labour was increase by 1.4 hours. Malpositions were found in 15% of cases where epidurals were used but in only 7% of cases where narcotics were used. Synthetic oxytocin augmentation of labour was found in 52% of women with epidurals and in 7% of women who had narcotic analgesia. Instrumentation (forceps and vacuum) was found in 27% of epidural cases compared with a rate of 16% among women not getting an epidural. Maternal fever was dramatically higher in the epidural versus narcotic analgesia groups—24% and 6%, respectively.

Maternal fever is a common side effect of epidural analgesia because it interferes with the sympathetic and parasympathetic nervous system balance, altering the body’s normal methods to eliminate heat. And since it is hard to know if the fever is due to infection or an epidural effect, a septic work-up is usually carried out following birth on both the mother and baby, including blood and possibly cerebral spinal fluid tests, along with frequent placement on prophylactic antibiotics. Additionally, increased maternal temperature can cause a rapid fetal heart rate and, thus, prompt a caesarean section due to concerns for fetal well-being.

Additionally, several studies have shown that perineal trauma increased two-fold in women who had had an epidural, due in part to an increased use of forceps and vacuum, which in and of themselves are associated with more perineal trauma (with or without epidurals).(13, 14)

Given all the other increases in intervention rates, we found it hard to understand why cesarean section rates were not also higher in the Cochrane meta-analysis. In fact, when we separated out the studies that made up the 2004 Cochrane meta-analysis, we found that, in those studies that showed no difference in cesarean section rates, epidurals had been administered after labour was well established (in the active phase at 4-5cm or more of cervical dilation). In the studies where epidurals were given early on in labour, before the active phase (before 4-5cm of cervical dilation)—the cesarean section rate increased more than 2.5 times. (15, 16)

Inadvertently, the Cochrane meta-analysis of epidural analgesia has caused more frequent use of epidurals, resulting in more continuous electronic fetal monitoring, immobility of the labouring woman, increased instrumentation and perineal trauma, and an increase in the cesarean section rate. Because more women will have received a cesarean section, another consequence will be an increase in problems in subsequent pregnancies relating to placentation issues (previa, accrete, percreta, abruption), infertility, and ectopic pregnancy.(17-20) In most maternity care settings, these down-stream consequences (‘collateral damage’) from epidural use are not discussed.

Dr. Klein’s final post next week will take a look at the realities of how epidural analgesia has “transformed birth.” All references for this series of posts can be found here: References _ michael klein post 

 

 

 

 

Posted by:  Michael C. Klein, MD, CCFP, FAAP(Neonatal-Perinatal),FCFP, ABFP
Emeritus Professor of Family Practice and Pediatrics
University of British Columbia
Senior Scientist Emeritus
Centre Developmental Neuroscience and Child Health
Child and Family Research Institute
4500 Oak Street
Vancouver, V6H 3N1
Tel: 604-875-2000 ext 5078
Fax: 604-875-3569
Email:
mklein@interchange.ubc.ca
 


[MK1]Mixing issues here

Uncategorized

  1. March 4th, 2011 at 09:54 | #1

    I just came across this post by Dr. Klein. There’s a lot of stuff here, and time prohibits me from addressing all of his claims, but I think it’s important for those people who happen to read it to discuss a couple of the claims he makes: that epidurals cause an increase in the cesarean rate, especially when they are given early in labor. As I evaluate the literature, I believe these issues have been resolved. I think the data clearly show that epidurals do NOT cause an increase in the rate of cesareans and they can be given at ANY time, without negative effects on the outcome of labor. If a reader is really interested in seeing the data for her/him self, I would simply read the following four MOST RECENT prospective studies of the effects of early epidurals on the progress and outcome of labor (none of which were mentioned in Dr. Klein’s post): Cynthia Wong (New England Journal of Medicine 2005), Gonen Ohel (American Journal of Obstetrics and Gynecology 2006), Cynthia Wong (Obstetrics and Gynecology 2009) and FuZhou Wang (Anesthesiology 2009). These studies unequivocally show that epidurals do cause an increase cesarean rate but also that they may be given ANY TIME in labor a woman wants one. The study by FuZhou Wang included nearly 13,000 women – and they gave epidurals as early as one centimeter dilation. I think the facts that epidurals don’t cause cesareans and that they can be given at any time during have been clear for a while now, and these four most recent prospective studies confirm them. Incredibly, like the proverbial horror movie monster, these myths simply refuse to die, despite multiple attempts to kill them with good, solid data. It’s the old: “Don’t confuse the argument with facts” approach. I review these studies and a lot of other must-know information in my book Epidural Without Guilt: Childbirth Without Pain. For anyone who wants to open their mind to the facts about state-of-the-art pain relief, I would humbly suggest that it’s a very good place to start!

  2. March 4th, 2011 at 16:02 | #2

    Oops!
    My sentence: “These studies unequivocally show that epidurals do cause an increase cesarean rate but also that they may be given ANY TIME in labor a woman wants one.” should have said: “These studies unequivocally show that epidurals do NOT cause an increase cesarean rate but also that they may be given ANY TIME in labor a woman wants one.”
    Well, at least I’ve gotten my 2011 mistake out of the way fairly eaerly in the year! :-)

  3. March 4th, 2011 at 16:17 | #3

    @Gilbert J. Grant, MD

    It is interesting that Dr. Grant references Wong, Ohel and the most recent huge study from China. I have covered much of this in the second and third parts of Science and Sensibility. I will start with Ohel.(1) This is an excellent study conducted by experienced researchers. It indeed shows no difference in Cesareans section rates when epidurals are given early. But the study takes place in a 10% Cesarean section environment. If the place where you plan to give birth has a 10-12% Cesarean section rate, you can assume that the procedure is given selectively and the care is superb and likely will not increase the Cesarean section rate. If you are giving birth in a setting with a 25% or more environment (usual for North America) then Ohels’s excellent study does not apply and early epidurals are part of the reason for the high Cesarean section rate.

    When Wong et al published a study in the New England Journal of Medicine on ‘‘neuraxial analgesia,’’ the debate on early epidurals heated up.(2) The term ‘‘neuraxial’’ was confusing to many. Most readers believed they were reading a study about epidural analgesia compared with narcotic analgesia. This was not the case. The authors, the editorialist and the press reported that women need no longer worry that an early epidural will lead to an increased likelihood of cesarean section. The study was a classical randomized controlled trial (RCT) analyzed by intention to treat. From the view-point of trial methodology, the study was well executed. From a clinical viewpoint, however, the trial did not address the issue of early epidural use and its effect on cesarean delivery. This trial was about two methods of helping women with the pain of early labor. Women randomly assigned to the ‘‘epidural’’ arm received a combined spinal-epidural approach. This approach is gaining in popularity, but it is not the standard, and does not address the issue of the role of early epidural analgesia with respect to cesarean section increases. Women in the ‘‘epidural’’ arm had an epidural catheter placed but not used. At first request for analgesia, women in the ‘‘epidural’’ arm received intrathecal (spinal) fententhe narcotic hydromorphone intramuscularly. At the time of first request for pain relief, 75 percent of women in both arms were already receiving synthetic oxytocin augmentation. Such a high level of synthetic oxytocin augmentation might or might not be generalizable to usual settings. On second request for pain relief, two-thirds of women in both arms were 4 cm dilated or more or were already in the active phase of labor. At this advanced state of cervical dilation, women in the neuraxial or intrathecal-‘‘epidural’’ arm received a low- dose epidural by means of the catheter already placed. In the narcotic arm, on second request for pain relief, women received hydromophone intramuscularly.

    The trial is misleading because it failed to emphasize that most women were in active or advanced (not early) labor when allocated to receive low-dose epidural or narcotic analgesia, and it employed intrathecal analgesia compared with intramuscular narcotic for early labor pain relief. This study, like many others that randomized women to receive an epidural in late or active labor, showed only that when women’s latent or early labor pain is managed with intrathecal (spinal), intramuscular narcotic, or other pharmacological or nonpharmacological means, an epidural in the active phase of labor does not increase the cesarean section rate.

    The study by Wang (3) is fascinating but inapplicable to life in North America. It is one of the largest studies ever conducted in obstetrics but the setting is so industrialized and interventive that one would hope that we will not be going in that direction.

    Bottom line is that if your institution has a Cesarean section rate of 10%, have a party to celebrate rather than conducting an RCT–and please tell us how you achieve this enviable rate. In such a place, epidurals will not contribute to a high Cesarean section rate. In fact, used selectively in a low Cesarean environment, they may very well help keep the rate low.

    References

    1. Ohel G, Gonen R, Vaida S, Barak S, Gaitini L. Early versus late initiation of epidural analgesia in labor: Does it increase the risk of cesarean section? A randomized trial. American Journal of Obstetrics and Gynecology 2006;194(3):600.
    2. Wong CA, Scavone BM, Peaceman AM, McCarthy RJ, Sullivan JT, Diaz NT, et al. The Risk of Cesarean Delivery with Neuraxial Analgesia Given Early versus Late in Labor. N Engl J Med 2005;352(7):655-665.
    3. Wang F, Shen X, Guo X, Peng Y, Gu X. Epidural Analgesia in the Latent Phase of Labor and the Risk of Cesarean Delivery: A Five-year Randomized Controlled Trial. Anesthesiology 2009;111(4):871-880.

  4. March 6th, 2011 at 00:56 | #4

    It’s interesting that Dr. Klein dismisses the four most recent randomized prospective studies that show early epidural (or spinal) anesthesia DO NOT increase the cesarean section rate. We are to ignore Ohel’s “excellent” study because it was conducted in a setting where cesarean rates are much too low compared to North America. We are to ignore Wong’s study because combined spinal – epidural analgesia was used (the spinal part prior to 4 cm dilated). And Wong’s second study (2009) is not even mentioned. This second study, done in women with induced labors had essentially the same findings as the first Wong study in women in spontaneous labor. I suppose we should ignore this one also because the combined spinal-epidural technique was used. While it is true that there are some differences between combined spinal-epidurals and plain epidurals, both yield very similar results, namely, profound pain relief and decrease maternal catecholamine levels. Plain epidurals and combined spinal-epidurals are used interchangeably by many anesthesiologists (I explain these techniques in my book “Epidural Without Guilt: Childbirth Without Pain”. Finally, we are told to ignore Wang’s study ( “one of the largest studies ever conducted in obstetrics”) because it was done in China where the setting is “so industrialized and interventive.” I live in New York. Our hospital has a cesarean rate of 29%. And I do believe that New York and the rest of the U.S. is industrialized. I suppose that the 29% cesarean rate means that we are “interventive” as well. So why exactly does this huge study of nearly 13,000 women not apply to the women who deliver at my hospital? So, to summarize: four recent prospective randomized studies that show that early epidurals (or combined spinal – epidurals in the case of Wongs two studies) DO NOT increase the rate of cesarean but they should be ignored. And we should continue to think that early epidurals lead to a greater chance of cesarean. What the reality? The reality is that there is NO CAUSITIVE LINK between early epidurals (or early combine spinal-epidurals) and cesareans. And ignoring well-designed prospective randomized studies, and telling women that there is a risk of getting state-of-the-art analgesia early in labor is unfair. Women should not be denied pain relief on the basis of their cervical dilation. If they are in pain, and they want the pain relieved – completely relieved – they should understand that they may choose an epidural or a spinal without concern that it will increase their risk of cesarean. Lastly, here’s a quick question for Dr. Klein: Is he aware of ANY prospective, randomized controlled trial that showed what he claims to be true, namely, that early epidurals cause an increased incidence of cesareans? Just wondering.

  5. avatar
    Gilbert J. Grant, MD
    March 7th, 2011 at 13:33 | #5

    Interesting that the comment I posted here in response to Dr. Klein’s response to me was removed….hmmmmmm…..
    I re-post it here:
    March 6th, 2011 at 00:56 | #24 Reply |
    It’s interesting that Dr. Klein dismisses the four most recent randomized prospective studies that show early epidural (or spinal) anesthesia DO NOT increase the cesarean section rate. We are to ignore Ohel’s “excellent” study because it was conducted in a setting where cesarean rates are much too low compared to North America. We are to ignore Wong’s study because combined spinal – epidural analgesia was used (the spinal part prior to 4 cm dilated). And Wong’s second study (2009) is not even mentioned. This second study, done in women with induced labors had essentially the same findings as the first Wong study in women in spontaneous labor. I suppose we should ignore this one also because the combined spinal-epidural technique was used. While it is true that there are some differences between combined spinal-epidurals and plain epidurals, both yield very similar results, namely, profound pain relief and decrease maternal catecholamine levels. Plain epidurals and combined spinal-epidurals are used interchangeably by many anesthesiologists (I explain these techniques in my book “Epidural Without Guilt: Childbirth Without Pain”. Finally, we are told to ignore Wang’s study ( “one of the largest studies ever conducted in obstetrics”) because it was done in China where the setting is “so industrialized and interventive.” I live in New York. Our hospital has a cesarean rate of 29%. And I do believe that New York and the rest of the U.S. is industrialized. I suppose that the 29% cesarean rate means that we are “interventive” as well. So why exactly does this huge study of nearly 13,000 women not apply to the women who deliver at my hospital? So, to summarize: four recent prospective randomized studies that show that early epidurals (or combined spinal – epidurals in the case of Wongs two studies) DO NOT increase the rate of cesarean but they should be ignored. And we should continue to think that early epidurals lead to a greater chance of cesarean. What the reality? The reality is that there is NO CAUSITIVE LINK between early epidurals (or early combine spinal-epidurals) and cesareans. And ignoring well-designed prospective randomized studies, and telling women that there is a risk of getting state-of-the-art analgesia early in labor is unfair. Women should not be denied pain relief on the basis of their cervical dilation. If they are in pain, and they want the pain relieved – completely relieved – they should understand that they may choose an epidural or a spinal without concern that it will increase their risk of cesarean. Lastly, here’s a quick question for Dr. Klein: Is he aware of ANY prospective, randomized controlled trial that showed what he claims to be true, namely, that early epidurals cause an increased incidence of cesareans? Just wondering.

  6. March 8th, 2011 at 13:02 | #6

    Forward to me for posting, by Dr. Klein:

    The studies that Dr. Gilbert used to make the claim that early epidurals do not increase the Cesarean section rate are those that the anesthetic community refers to as well. Dr. Gibert claims that he has science on his side, meaning that the randomized controlled trial (RCT) is the gold standard of truth in such affairs, or what is known as Level I evidence. This point of view is generally shared in the scientific community, but increasingly some of the very progenitors of the RCT in maternity care, such as Murray Enkin, one of the authors of the “bible” of RCTs in maternity care, “Effective Care in Pregnancy and Childbirth,” are having second thoughts.

    RCTs are best applied to simple problems like comparing drug A to drug B. Complex systems of care, involving human attitudes, beliefs and behavior may be unsuitable for study by an RCT. I would contend that epidural analgesia may possibly be one of those. Enkin is often quoted as saying that the results of RCTs provide answers for those and only those settings or conditions under which the RCT took place. If these conditions do not apply in your setting, then the results don’t apply (no external validity). It is also possible to design the perfect RCT from an organizational and “scientific” point of view that is, nevertheless, clinical nonsense. At another time I can provide examples of those.

    Wong’s studies are not about epidural analgesia but the combined spinal-epidural technique. Ohel’s excellent study took place in a 10-12 % Cesarean section environment and is his results pertain only to such an environment. Wang’s study reminds me of the terrifying movie: “Manufactured Landscapes,” which shows China’s mind-numbing way of manufacturing the goods that we in the West buy. The setting for this enormous study was one in which virtually everybody got an IV, an epidural, continuous electronic fetal monitoring, synthetic oxytocin augmentation and very little personal care (I wrote to the investigator). Hopefully not the way we would like to see maternity care go.

    Dr. Gilberts says that I reject “science.” Hardly, I did the only RCT of episiotomy in North America, showing that used routinely it causes the very trauma it was supposed to prevent, and is considered a key contributor to the reduction in episiotomy rates that we are now experiencing. But that was an easy problem compared to epidural anesthesia. The aware practitioner could just decide to put the scissors away. Simple problem, simple solution.

    If you live in Ohels’ Israeli superb 10% Cesaran section environment or the equivalent, that study has meaning for you. They are giving outstanding, enviable care. Love to know how they do it. If you expect the industrialized care in Wang’s China, that study will appeal to you. These two studies have internal validity but lack external validity for most North American settings. This is epidemiology 101. RCTs perfectly reflect the conditions in which they take place. If those are your conditions, they speak to you. If not, they do not.

    Finally Dr. Gilbert wants me to give him an example of an RCT that that shows that epidurals given early increase the Cesarean section rate. Otherwise, by implication, I ought to be silent. I did such a study. It was not an RCT per se but a study of the RCTs that made up the previous Cochrane and the new (deeply flawed) Cochrane meta-analysis of epidural analgesia compared with narcotics. Nobody has compared epidurals with physiological care, such as midwives give. What I did was to remove all the RCTs from the Cochrane meta-analysis that randomized women in the active phase of labor (greater than 4-5 cms). A separate analysis of those RCTs demonstrated that late epidurals DO NOT increase the Cesarean section rate. When I then looked at the remaining RCTs, they increased the Cesarean section rate by more than 2 ½ times. This is known as a “sensitivity analysis.” It is a common technique that should have been applied by Cochrane rather than myself. It was strange that they did not, as they did a large number of other sensitivity analyses. I think that it is time that these Cochrane studies and the RCTs that make up the Cochrane meta-analyses involve other people than anesthesiologists. They are clearly in a conflict of interest position. Better studies would be multidisciplinary and involve some of the midwives who have produced a literature that demonstrates strikingly low epidural and Cesarean section rates.

    I think that it is time for Dr. Gilbert and I to agree to disagree and both move on.
    Michael

    Michael C. Klein, MD,CCFP,FAAP (Neonatal-Perinatal),FCFP,ABFP,FCPS
    Emeritus Professor Family Practice & Pediatrics
    Director Clinician Scholars Program
    Department Family Practice, University British Columbia
    Senior Scientist Emeritus
    Centre Developmental Neurosciences & Child Health
    Child and Family Research Institute
    Listmaster: Maternity Care Discussion Group (MCDG)
    Rm L408 (mail), E419A (actual)
    4500 Oak St Vancouver, BC Canada V6H 3V4
    mklein@interchange.ubc.ca 604-875-2000 ext 5078.
    http://www.michaelcklein.ca

  7. avatar
    Janice Williams
    August 31st, 2011 at 17:23 | #7

    And what of the mothers? Not all mothers strive for a ‘natural’ birth and many mothers may be adversely impacted by being forced to undergo one. Truly there can be no ‘ideal’ rate of epidurals or csections as it will depend on what best meets the needs of the specific mother and baby. Shouldn’t the focus be on maternal satisfaction with the birth? This might be a ‘natural’ birth if that is what she desires (being fully informed of all the risks and benefits of it), but it may also be a more medicalized birth. The focus needs to shift so that expectations and experiences are more in line with one another. Aggressively pushing down csection rates and epidural rates might have the unintended consequence of increasing rates of post-natal depression and post-natal post traumatic stress disorder.

  8. September 20th, 2012 at 00:38 | #8

    Can we not just fall back on the idea that mother nature intended for birth to be hard work. When women journey through labour and delivery a mother is born. She’ll learn to give more than she ever thought she could to bring her baby earth side with compassion, patience, strength and love…the foundation of motherhood!

  9. avatar
    Eric Swidler
    October 3rd, 2013 at 22:54 | #9

    Tanya Malcolm :
    Can we not just fall back on the idea that mother nature intended for birth to be hard work. When women journey through labour and delivery a mother is born. She’ll learn to give more than she ever thought she could to bring her baby earth side with compassion, patience, strength and love…the foundation of motherhood!

    Isn’t that like saying that mother nature intended people to die of diseases like polio, chicken pox and diphtheria so we shouldn’t give people vaccinations that are available? It seems to me that we should acknowledge the fact that “mother nature” isn’t perfect. That’s why she created human brains which are capable of mitigating her lapses and inefficiencies, with inventions like vaccines or the eye-glasses I’m wearing as I read this website.

  1. April 8th, 2011 at 23:26 | #1
  2. April 19th, 2011 at 08:58 | #2
  3. July 26th, 2011 at 13:17 | #3