Artigo sobre o evento da OAA (Obstetric Anaesthetists Association)

Clipping produzido em Maio pela Profa. Joanne Douglas, de Vancouver – Canadá. Ela comenta sobre o evento da OAA (Obstetric Anaesthetists Association), em Londres, sobre os papers discutidos, palestras proferidas e posters apresentados. Parte deste material está sendo usando para atualizar nossos protocolos.

I want to apologize for the fact that this edition is arriving a little late.  I was away for three weeks – vacation in Italy followed by some time in England where I attended the Obstetric Anaesthetists’ Association annual meeting.  The quality of this meeting has steadily increased and there were a few interesting presentations that I thought I would share with you. 

Cardiac Disease:

There were three speakers in this session:  two cardiologists who discussed congenital and acquired cardiac disease and Dr. Rob Dyer, an anesthesiologist from South Africa who discussed hemodynamic monitoring for these patients.  There was some interesting discussion about whether OB anesthesiologists will require some basic skills in transthoracic echocardiography in the future.  You may want to review the article by Dennis AT on Haemodynamics in women with untreated pre-eclampsia.  Anaesthesia 2012;67:1105-18. 

Two Other Presentations

Six papers were considered for the “best paper” award.  The topics included risk factors for severe postpartum sepsis as identified using the UK Obstetric Surveillance System (impressive as had 100% participation – septic shock was associated with Group A streptococcus and for each maternal death there were 50 cases with life threatening morbidity); whether local anesthetics and lipophilic opioids act synergistically or additively when placed intrathecally for labor analgesia (took 4 years to get 300 laboring women – found it was synergistic); whether two tests for fibrinogen could be used to predict major obstetric hemorrhage (enrolled patients with PPH of >1000 mL – FIBTEM® gives a faster result – 20 min vs about 60 min); the force needed to insert an epidural needle in a porcine spine (basically they were testing their system for measuring pressure as they wanted to develop a simulator for teaching epidurals – their presentation differed from abstract as presented human data not porcine); an audit following introduction of an enhanced recovery in obstetric surgery protocol (found that women went home earlier but there were several issues – did not present data as to number of patients who had a previous C/S vs those who were having their first child by elective E/S); and what happened to cardiac output following a colloid preload prior to spinal anesthesia for elective cesarean section in patients with treated severe preeclampsia (significant increase due to increased HR and SVR – recommended measuring CO in order to determine whether appropriate to administer more fluid).  See the May supplement of IJOA for the abstracts of these six studies.  We will have to await the full publication of these studies to determine their value.

The other interesting presentation was by Dr. Cally Hoyt, the Immediate Past President of SOAP.  It was entitled Top Papers Influencing Clinical Practice 2012-2013.  This was her personal perspective and she provided the reasons for her selections.  A big thank you to Cally for bringing these papers to everyone’s attention. 

The papers, the order of their presentation and the reasons for presentation (that I can remember) follow:

#1:  Dean C, Douglas J.  Magnesium and the obstetric anaesthetist.  Int J Obstet Anesth 2013;22:52-63.  As a co-author on this paper you might say I was pleased to see this one chosen.  Dr. Hoyt liked it because each of the uses was rated as to the evidence.   As well, she highlighted the discussion about its new use as a co-analgesic.

#2:   Gutierrez S et al.  Reversal of peripheral nerve injury-induced hypersensitivity in the postpartum period.  Role of spinal oxytocin. Anesthesiology 2013;118:152-9.  This paper was discussed in the January OB Div News and is worthwhile reviewing again.  It was accompanied by an editorial by Cynthia Wong and Pamela Flood who pointed out that although the data suggested that chronic pain was less likely to occur following surgery in parturients possibly secondary to spinal oxytocin, it still is an ongoing problem and more studies are needed.

#3:  This paper in an on-line journal reports on maternal and cord serum cytokine changes with continuous and intermittent labor epidural analgesia (Mantha VR et al.  Sci World J 2012 Article ID 607938 (doi 10.110/2012/607938)).  The reason for epidural-associated fever is, as yet, unknown.  Theories include infection, altered thermoregulation and inflammation.  In this current report Mantha et al provided additional results to their previous publication which found that fever was less common with intermittent administration of local anesthetic (on-demand) vs continuous infusion (Mantha VR et al.  Int J Obstet Anesth 2008;17:123-9).  The 2012 publication reported that inflammatory cytokines increased during labor and this did not differ between the two techniques.  This suggests that inflammation is less likely to be the cause.  In this follow-up paper IL-6 increases during labor but there was no difference between the groups.  An Honorable Mention was given to a paper by Wang L-Z.  Int J Gynecol Obstet 2011;113:40-3 which found that epidural dexamethasone alleviated maternal temperature and decreased IL-6 suggesting that non-infectious inflammation may be the cause.  Both of these studies have limitations and it is obvious that the final answer is not in.

#4:  Barton JR, Sibai BM.  Severe sepsis and septic shock in pregnancy.  Obstet Gynecol 2012;120:689-706.  Dr. Hoyt liked this review and I agree with her.  The authors provide a comprehensive review on this topic and point out the importance of prevention and early intervention to decrease the incidence of severe morbidity and mortality.

#5:  Clark SL, Hankins GDV.  Preventing maternal death.  10 clinical diamonds.  Obstet Gynecol 2012;119:360-4.  This is another paper previously reviewed in OB Div.  The authors briefly discussed 10 errors that account for many cases of maternal death and recommend developing protocols to deal with these situations.

#6:  Opotowsky AR.  Maternal cardiovascular events during childbirth among women with congenital heart disease.  Heart 2012;98:145-51.  This study used the Nationwide In patient Sample (1998-2007) to identify the study population.  They found that the combination of death, heart failure, arrhythmia, cerebrovascular incident (transient ischemic attack, embolic events) and unspecified cardiovascular complications were more common in women with congenital heart disease (CHD) (OR 8.4,95% CI 7.0-10.2) even after adjusting for multiple covariates.  The sample size of women with CHD was 30,500.  Maternal death was quite rare in this study 0.15%.  The most common adverse event was arrhythmia.  Women with CHD were also more likely to have a cesarean delivery.  The authors point out that the results of this study are likely an underestimate due to the retrospective nature of the study.  An honorable mention under this same category was Roos-Hesselink JW, et al.  Outcome of pregnancy in patients with structural or ischaemic heart disease:  results of a registry of the European Society of Cardiology.  Eur Heart J 2013;34:657-65.  This study also used a database to find that most patients with heart disease can undergo pregnancy and delivery safely provided adequate pre-pregnancy evaluation is done and good care is provided peripartum.  The exception to this is cardiomyopathy.

#7:  Dutton RP.  Haemostatic resuscitation.  Br J Anaesth 2012;109 (S1):i39-i46.  Although not specifically aimed at obstetric situations, this is an excellent review and points out that changes to resuscitation include using less volume replacement, deliberate hypotension and aggressive coagulation improvement.  The authors again point out the need for more studies in this area and have some specific recommendations. 

#8:  Cortet M, et al.  Association between fibrinogen level and severity of postpartum haemorrhage:  secondary analysis of a prospective trial.  Br J Anaesth 2012;108:984-9.  As noted above many groups are looking at the fibrinogen level in an effort to predict the risk of postpartum hemorrhage.  This study, highlighted by Dr. Hoyt, found that the fibrinogen level when PPH is diagnosed indicated the severity of PPH.

9:  Solomon C et al.  Haemostatic monitoring during postpartum haemorrhage and implications for management.  Br J Anaesth 2012;109:851-63.  This review discusses the various hematological tests and testing devices that can be used to follow the course of PPH.  They suggest that thromboelastography and thromboelastometry may provide more rapid results than traditional laboratory testing but that more work is still needed to determine normal reference ranges.

10:  Palanisamy A.  Maternal anesthesia and fetal neurodevelopment.  Int J Obstet Anesth 2012;21:152-62.  This was the last recommended article and it is an excellent review on this subject.  As you may recall one of the concerns of the author was the danger of extrapolating animal studies to humans. 

With respect to two of the abstracts presented at the OAA and two of the papers reviewed by Dr. Hoyt you may want to look at the April issue of IJOA.  In that issue, there were two editorials:  one related to PPH and fibrinogen levels and one related to enhanced recovery in obstetrics.  As well there was a review of chronic pain after childbirth.

Butwick AJ.  Postpartum hemorrhage and low fibrinogen levels:  the past, present and future.  IJOA 2013;22:87-91.  The title of this editorial basically tells it all.  Again, more research is called for but Dr. Butwick feels that there will be important changes in our management of patients with severe obstetric hemorrhage.

Lucas DN, Gough KL.  Enhanced recovery in obstetrics—a new frontier?  IJOA 2013;22:92-5.  In this editorial the authors point out the way in which postoperative care is managed with the “fast track” process and discuss its applicability to obstetrics.  The major concern for this is safety of mother and neonate which will have to be balanced against potential cost savings to hospitals.

Landau R, Bollag L, Ortner C.  Chronic pain after childbirth.  IJOA 2013;22:133-45.  These authors point out the importance of developing models that predict chronic pain so that targeted interventions can be made.  An interesting review.

Some Other Interesting Papers:

  1. Guglielminotti J, et al.  Assessment of pain during labor with pupillometry:  a prospective observational study.  Anesth Analg 2013;116:1057-62.  The authors foresee this technique when communication is impossible.
  2. Bloor M, Paech M.  Nonsteroidal anti-inflammatory drugs during pregnancy and the initiation of lactations.  Anesth Analg 2013;116:1063-75.  This review looks at NSAIDS, their role in obstetrics and postpartum analgesia. 
  3. Ankichetty S et al.  Case report:  rhabdomyolysis in morbidly obese patients:  anesthetic considerations.  Can J Anesth 2013;60:290-3.  Although this is a case of a hysterectomy it will be of interest to OB anesthesiologists.

Joanne Douglas, MD
Vancouver, BC