James C. Eisenach, M.D., Editor
The 29th Annual Meeting of SOAP. Southhampton, Bermuda, April 13–17, 1997.
The 29th annual meeting of SOAP was held at the Southampton Princess Hotel in Bermuda. The scientific sessions were held in an ergonomically designed, state-of-the-art amphitheater featuring multimedia capabilities and simultaneous dual projection. SOAP is the officially recognized component society of the American Society of Anesthesiologists' representing the practice of Obstetric Anesthesiology. The Society currently lists more than 1,300 active members, and for the second consecutive year, more than 500 members attended the annual meeting.
David J. Birnbach, M.D., president-elect and meeting host, opened the meeting with warm words of welcome; promising an exhilarating meeting and unlimited sunshine. Although he kept his word about the outstanding caliber of the meeting, it rained for the first 3 days. Several registrants suggested that the inclement weather was part of a plan to keep all registrants at the scientific sessions. Although not intentional, it worked!
This year's meeting was enhanced by two new features; a series of debates on controversial obstetric anesthesia topics and an interactive audience response system allowing participants to compare their practice with their colleagues in the audience. In addition to the new features, scientific papers continued to be presented in the traditional oral, poster, and poster-oral sessions. Four invited lectures were continued this year, “What's New in Obstetric Anesthesia,”“What's New In Obstetrics,”“What's New in Meeting Abstracts,” and the “Fred Hehre Lecture,” making the meeting a delightful mix of old and new.
The first scientific session began with G. M. Bassell, M.D., moderating the Gertie Marx symposium. This symposium honors Dr. Gertie Marx, one of the pillars of obstetric anesthesia. This symposium is the Society's forum for research performed by resident and fellow physicians. Prizes are awarded to the three outstanding research presentations. Judges this year, included Drs. Mike Finster, Sheila Cohen, Gerry Bassell, Eli Alon, and Dan Benhamou. Unfortunately, for health reasons, Dr. Gertie Marx was unable to attend this year's meeting and could not be present at the symposium. From the 25 abstracts that were submitted, six finalists were chosen for presentation. The six finalist papers were, in order of presentation:
Dr. M. G. Parry (Royal Free Hospital, London, UK) presented the “Assessment of Dorsal Function using Somatosensory Evoked Potentials after Ambulatory Combined Spinal Epidural Analgesia for Labor.” Using somatosensory-evoked potentials, the authors concluded that because CSE analgesia is unlikely to result in significant impairment of dorsal column function, ambulation remains as safe option, providing that lower limb motor power is present.
Dr. P. Atkinson (Thomas Jefferson University, Philadelphia, PA) presented “How Common is Respiratory Depression in Laboring Patients Who Receive Intrathecal Sufentanil Alone or Following IV Opioids?” These authors found that parturients who receive intrathecal sufentanil alone or after receiving intravenous opioids decrease their oxygen saturation and are more likely to need oxygen supplementation.
Dr. D. Forrester (The Johns Hopkins University, Baltimore, MD) presented “Adenylyl Cyclase Activity in Rat Myometrium Increases During Pregnancy.” Results of this study show that pregnancy is associated with increased basal and stimulated adenyl cyclase activity in the uterus.
Dr. J. Campagnuolo (St. Luke's-Roosevelt Hospital Center, Columbia University, NY) presented “Determination of Dermatomal Level of Spinal Anesthesia for Cesarean Section. How Important is Testing?” This study demonstrated that the dermatomal level of anesthesia observed when tested from caudad to cephalad direction is often different than when tested in the opposite (cephalad to caudad) direction and may have clinical import.
Dr. M. Foss (Wake Forest University, Winston-Salem, NC) presented “Dose Response Study of Intrathecal Sufentanil in Laboring Patients.” This study established an ED50 for intrathecal sufentanil necessary to provide labor analgesia for 60 min. The results will be useful in calculating full dose-response curves and in comparing the effects of intrathecal sufentanil alone to sufentanil plus adjunctive agents.
Dr. W. E. Meadows (St. Luke's-Roosevelt Hospital Center, Columbia University, NY) presented “Skin Disinfection Prior to Initiation of Epidural Anesthesia. A comparison of Two Methods of Antisepsis.” This study compared the efficacy of skin disinfecting when using providone iodine an Duraprep[trademark symbol], a new disinfectant that contains an iodophor-in-alcohol solution. The results suggest that Duraprep was at least as effective as providone iodine solution and may offer some advantages.
Prizes for first, second, and third place were awarded at the annual banquet to Drs. Foss, Forester, and Campagnuolo.
The first of three SOAP debates, “5% Lidocaine Spinals Should Not Be Used in Obstetrics,” was moderated by Dr. Tony Rocke of Durban, South Africa. Participants were Dr. Markus Schneider of Switzerland for the supposition and Dr. John Downing of Vanderbilt University against the supposition. The topic was chosen because of the controversy surrounding the continued use of spinal lidocaine. The audience response system was used to poll the audience before and after the debate. Of interest, 53% of participants had stopped using undiluted 5% hyperbaric spinal lidocaine.
The Fred Hehre Lecture followed the debate. Mike Finster, M.D., Professor of Anesthesiology, Obstetrics and Gynecology at the College of Physicians and Surgeons of Columbia University delivered this eponymous lecture, named for one of the founding members of SOAP. This lecture titled, “Abandoned Techniques and Drugs in Obstetrics and Obstetric Anesthesia,” reviewed forgotten obstetric anesthesia techniques including twilight sleep, rectal ether, and lumbar sympathetic block, citing their merits and drawbacks.
Dr. William Camann of the Brigham and Women's Hospital in Boston moderated the first of two poster review sessions. Dr Camann reviewed the 51 poster presentations displayed on Monday. A second poster review, led by Dr. Chris Rout of University of Natal, South Africa, discussed Tuesday's poster presentations. Both moderators led excellent reviews that compared, contrasted, and critiqued the results of more than 100 studies. Of special interest in the poster presentations:
Dr. M. C. Norris and Dr. S. T. Fogel from Washington University found that the incidence of false-negative aspiration in laboring women appears comparable to the reported incidence of false-negative air tests and false-negative epinephrine test doses. False-positive results occur occasionally with air and epinephrine, but not with aspiration.
Dr. J. Downing and associates at Vanderbilt University presented data that showed that halothane effectively attenuates the human placental vasoconstriction response to hypoxia. Because the vasoconstrictor response is presumably a protective mechanism evoked by hypoxia, any interference with this process may be important.
Dr. M. G. Richardson and Dr. Richard Wissler from the University of Rochester presented data suggesting that very obese parturients were unlikely to experience post-dural puncture headaches after dural puncture with an 18-gauge needle. Similarly, Dr. E. Bell from Duke University evaluated the incidence of headache in morbidly obese parturients after continuous spinal anesthesia through a 17-gauge needle, reporting a decreased incidence as well.
Two posters dealing with education were viewed with interest by meeting registrants. Dr. R. Patel and colleagues from Magee-Women's Hospital, University of Pittsburgh, reported on full scale simulation for training physicians in the management of critical obstetrical events and found crisis management training to be a valuable tool.
Dr. W. Meadows and colleagues from St. Luke's-Roosevelt Hospital Center, Columbia University, presented results of their study using video analysis and self appraisal as a new method to teach residents to minimize errors while performing epidural analgesia.
Dr. E. Yun and colleagues from the Albert Einstein College of Medicine and SUNY Stony Brook, presented data evaluating cardiopulmonary bypass on uterine blood flow in pregnant ewes. They found that CPB is associated with reductions in UBF and fetal oxygenation that are more severe when low pump flows are used.
There were 17 oral presentations and 5 poster-oral presentations during the scientific sessions. Although it is beyond the scope of this review to highlight each abstract, a few will be discussed.
Dr. Grafe and colleagues from Duke University and the University of Iowa presented a study titled “Brain Injury in the Immature Sheep Fetus Following 10 Minutes Complete, Reversible Umbilical Cord Occlusion.” The authors found that 10 min of cord occlusion is associated with fetal EEG isoelectricity, severe hypoxemia with acidosis, and increased fetal brain extracellular glutamate. The authors speculated that increased brain glutamate is involved in hypoxic brain injury.
Dr. S. Palmer and colleagues from the University of Colorado, noted that the chronic hypoxia of residence at high altitude is associated with an increased risk for developing preeclampsia. According to the authors, even normotensive women at high altitude have an altered blood pressure response to pregnancy.
Dr. Langevin and colleagues from the University of Florida, Gainesville, reported on the effect of nitroglycerin (NTG) on the uterus. This study performed on strips cut from the incised edges of rabbit uterus was conducted to determine if the action of NTG in the uterus could be mediated by nitric oxide. The authors concluded that NTG increases uterine compliance by a mechanism that is not nitric oxide-mediated.
Dr. A. Holdcroft and colleagues from the Royal Postgraduate Medical School in London, UK, presented one of the most interesting papers of the meeting titled, “Decrease in Brain Size in Normal Pregnancy.” The authors performed serial magnetic resonance scans in 10 women finding a decrease in brain size during normal pregnancy.
The second SOAP debate was a collegial match between Drs. James Thorp and David Chestnut, adroitly moderated by Dr. Trevor Thomas, President of the Obstetric Anesthetists Association (OAA). Dr. Thorp took the position he has taken in his numerous publications, associating epidural analgesia was associated with an increased risk of cesarean delivery. Dr. Chestnut argued, as he has in his publications, that epidural analgesia does not increase cesarean section rates. Because the debate, 8% of the audience agreed with Dr. Thorp that epidural analgesia increases the cesarean delivery rate and as a result of his convincing arguments, his supporters increased to 12% after the debate. Both speakers emphasized the potential advantages of epidural analgesia despite their differences of opinion.
The “What's New In Obstetrics” lecture was delivered by Valerie Parisi, M.D., M.P.H., who is chair of Obstetrics and Gynecology at SUNY Stonybrook. SOAP officer Dr. Parisi discussed several exciting developments, including recent advances in the management of prematurity and hypertensive disorders of pregnancy.
Wednesday morning began with a neonatology breakfast panel moderated by McCallum Hoyt, M.D., of Case Western Reserve University. Speakers included Barry Bloom, M.D., of the University of Kansas discussing meconium resuscitation, Angela Bader, M.D., of Harvard University discussing the neonatal effects of epidural analgesia, and Farrokh Shahrivar, M.D., of Columbia University discussing the neonatal implications of maternal HIV infection.
The “What's New in Obstetric Anesthesia” lecture, a highlight of the SOAP meeting each year, was given by Richard Wissler, M.D., Ph.D., Director of Obstetric Anesthesia at the University of Rochester and SOAP officer. The audience was treated to a review of more than 1,200 articles published during the past year that may affect obstetric anesthesia practice.
After oral presentations from the Best Paper, Drs. Sanjay Datta and Fred Zuspan presented the “Best Paper of the Meeting Award” to David J. Birnbach, M.D., and colleagues for their study entitled “Does Epidural Analgesia Protect Against Cesarean Section in Nulliparous Patients. A Retrospective Review of 13,203 Patients.” This study identified oxytocin augmentation and maternal age as the most significant risk factors in cesarean delivery. When controlled for other variables, the administration of epidural analgesia was actually associated with a decreased risk of cesarean section.
A new award for promising research in perinatal medicine. The Zuspan Award, was presented to Dr. El-Sayed for his work in conjunction with others entitled, “High Dose Intravenous Nitroglycerin for the Acute Tocolysis of Preterm Labor: A Preliminary Report of a Prospective, Randomized Trial.”
A luncheon panel, “The State of the Art in Local Anesthetics,” moderated by Sanjay Datta, M.D., Professor of Anaesthesia at Harvard Medical School, included talks by Drs. Alan Santos (Albert Einstein), Ted Cheek (University of Pennsylvania), Joanne Douglas (University of British Columbia), and Gordon Lyons (St. James University Hospital, Leeds, UK). The advantages of the new local anesthetic agents, levobupivacaine and ropivacaine, were discussed in detail by panel members who have all had extensive experience with these new agents.
Thursday began with “The Best Days of Our Lives,” a reminiscence of obstetric anesthesia practice over the past 40 yr, featuring Drs. Mike Finster, Brett Gutsche, and Robert Hustead. Dr. Gertie Marx joined the panel via telephone, and as always fascinated the audience with her memories of obstetric anesthesia in the “good old days.”
David Birnbach, M.D., moderated the third SOAP debate, “Parturients Should Not Be Allowed to Eat in Labor”, featuring Charles Gibbs, M.D., speaking for and C. C. Rout, F.F.A.R.C.S., against the supposition.
An international panel moderated by Tony Rocke (South Africa) and including Eli Alon (representing the European Society of Obstetric Anesthesia), Remi Bourlier (Paris), and Trevor Thomas (representing the Obstetric Anaesthetist's Society) discussed differences and similarities in the practice of obstetric anesthesia throughout the world. At the conclusion of the panel, the SOAP travel scholars for 1997 were introduced and encouraged to join the discussion. The 1997 SOAP travel scholars included Carla Fuentes Sanchez, M.D., (Managua, Nicaragua), Elisa Ragaza, M.D., (Manila, Philippines), and Loo Chee Chuen, M.D. (Singapore).
Dr. Birnbach thanked the participants and invited them to attend the 1998 SOAP meeting to be held in Vancouver, British Columbia on April 29-May 2, 1998.
David J. Birnbach, M.D.
St. Lukes-Roosevelt Hospital Center; Department of Anesthesiology; 1000 10th Avenue; New York, New York 10019
Gerald A. Burger, M.D.
Cleveland Clinic Foundation; Cleveland, Ohio 44195