521 Maternal and Fetal Cardiovascular Effects of Intravenous Adenosine
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Vo lume 1 68 N umbe r I , Part 2 519 THE EFFECT OF EPIDURAL ANALGESIA ON THE FETAL ECG WAVEFORM. A. Gordon x , M.P. Umstad X , K W Murohyx, K. Phillipsx, A.D. Cameron, J. Fleming x . The Queen Mother's Hospital, Glasgow, Scotland. OBJECTIVE: To assess the ellect of epidural analgesia on the fetal ECG waveform. STUDY DESIGN: The fetal ECG waveform of 8 mothers receiving lumbar epidural analgesia with 0.25% bupivacaine were recorded with a computarised letal ECG monitor (STAN, Cinventa, Sweden). The fetal ECG complexes were analyzed for 20 minutes prior to epidural administration and for 40 minutes afterwards. The PR-interval and T/QRS ratios were measured at 5 minutes intervals. Confidence intervals analysis was used to assess the significance of differences between the mean values. RESULTS: Of the 8 fetuses studied, 5 demonstrated a significant rise in the T/QRS ratio following epidural analgesia, 2 showed a fall and the other remained unchanged. The effect of epidural analgesia on the PR- interval was variable; it was prolonged in 4 cases and shortened in the other 4 cases . CONCLUSIONS: The administration of epidural analgesia appears to significantly increase the T/QRS ratio 01 the fetal ECG waveform but has a variable effect on the PR-interval. Further evaluation is required. 520 EPIDURAL ANALGESIA AND OPERATIVE DELIVERIES. !: G Eglinton. T Tomai x , Y Shinx. Dept's. Ob/Gyn and Anesth, Georgetown University, Washington, D.C. OBJECTIVE: The objective of the study was to investigate the relationship between epidural analgesia in labor and non-spontaneous delivery. The null hypothesis was that operative deliveries occurred with similar frequency among panurients delivering with and without epidural analgesia. STUDY DESIGN: Medical records were reviewed for 1218 consecutive obstetric deliveries identified by computer listing provided by the medical records department. After exclusion of all patients with planned cesarean or induction of labor, attempted labor after prior cesarean delivery. multiple gestation. or nonstandard epidural regimens. 695 records were evaluable. Variables usually thought to be clinically important in their effect on mode of delivery were investigated via univariate parametric and nonparametric analyses. as appropriate. After these independent comparisons, the statistically significant variables were each tested using univariate logistic regression. Variables that remained both statistically and clinically significant were then tested in a multivariate logistic regression analysis to detennine which variables predicted the greatest relative risks of non-spontaneous delivery. RESULTS: Epidural analgesia, nulliparity, and oxytocin augmentation were associated with increased risk of operative vaginal delivery (odds ratios = OR 8.3 [confidence interval = CI 3.1 - 22.21, 3.0 [CI 1.7 . 5.11 , 3.0 [CI \.6 - 5.91, respectively). Cervical dilation> 3 em on admission was associated with a decreased risk (OR 0.26 [CIO.\3 - 0.5)). Epidural analgesia and nUlliparity were associated with an increased risk of cesarean delivery (OR 4.4 [CI 2.3 . 8. 41. OR 2.6 [CI 1.6 - 4.21, respectively). CONCLUSIONS: Using a mult.ivariate analysis to control for confounding variables, among clinical\y significant factors evaluated, epidural analgesia was most strongly associated with non-spontaneous and cesarean delivery. This relationship warrants further investigation. 521 SPO Abstracts 439 MATERNAL AND FETAL CARDIOVASCULAR EFFECTS OF INTRAVENOUS ADENOSINE. B. Mason X , D. Ogunyemi X , O. Punla X , B. I(oos. Dept. Ob/Gyn, UCLA, Los Angeles, CA. OBJECTIVE: To study the cardiovascular and blood gas effects of maternal adenosine (ADO) infusion on the ewe and fetus. STooY DESIGN: Two sets of experiments were performed wi th 5 gr avid ewes (0.8 term) in each group . Under chronic cond i t ions , 200ug/kg/min ADO was infus ed via the femoral vein of the ewe s as either a single bolus or continuous 60 minute i nfu sion. Blood pressure (BP), heart rate (HR), arterial blood gases (ABG) and hemoglobin concentrations (Hb) were mon ; tored in both the ewe and the fetu s. All data was analyzed us ing two - wa y analysis of variance. RESULTS: During the boluses, there was a transient fall in maternal HR fo ll owed by a brief rise in HR (mean 23.16 bpn) with retu rn to bas eline values within 1 mi nute after the bolus (p<. OO1) . Maternal diastolic BP showed a brief transient fall at th e same ti me (mean 19.5±4_9 nmHg); p<.OO1). There was no si gnif ica nt change in maternal sys tolic BP, ABG, Hb, and fetal BP, HR, a nd Hb were not affected. During the continuous infu s ions, there was a significant ri se in maternal HR (mean 38.13 bpm; p<.OOI) and a signific a nt fall in diastolic BP (mean 20.4 . 10.7 nmHg; p<.OOI) both of which were sustained throu ghout the infusion. Maternal Hb increased significantly during the infusion but maternal s ystolic BP, ABG, and fetal HR, BP, ABG, and Hb were unchanged. A.ll changes returned to basel ine a fter infusions were dis c ontinued . CONCLUSION : Al th ough intravenous acininistration of adenosine t o p re gnant e wes causes significant changes in maternaL BP, HR , and Hb, the changes are brief and do not significanUy aff ect the cardiovas cular or r es piratory performance of the fetu s. (Suppo rted by HD 18478) 522 ELECTROCARDIOGRAPHIC ABNORMALITIES WITH SUBCUTANEOUS TERBUTALINE PUMP THERAPY. M. Alv arez, c.J. Lockwood, A. Ghidini, M. Pa idas, J. Stone, R.L. Berkowitz, L. Lynch. Mt. Sinai School of Medicine, New York, NY. OBJECTIVE: Intravenous (IV) beta mimetic therapy for preterm labor has been associated with myocardial infarction and el ectrocardiographic (EKG) abnormalities. Since subcutaneous (s.q .) betamimetic therapy via a pump ha s been proposed as an alte rnative to IV tocolysis, we evaluated the mate rnal EKG respo nse to s.q. terbutaline pump the rapy . STUDY DESIGN: Consecutive consenting patients (n=1 8) admitted with preterm labor were placed on an EKG Holter monitor prior to therapy. Terbutaline S04 was admini s tered as the initial tocolytic therapy via a s.q. pump at a basa l dosage of 0.05 mg/hr with boluses of 0.25 mg eve ry 4 hrs . An average of 48 hours of EKG recording were analyzed by paired t-tests. RESULTS: The mean maternal a ge and ges tati onal age were 31 years and 27 weeks, respectively, with 61 .1 % Si ngleton, 22.00/0 twin and 16.7% triplet gestations. There were no differences in the mean number of premature ventricul ar co ntractions (3 and 3.5, p=<J.8), or in the mean heart ral e (127 and 136 bpm, p=O.l) be for e and after treatment, respectively. Mo re cardiac pauses> 1 sec were present after treatment (7.0 vs. 0.4, p=<J .02) . However, no e pisodes of Qr interval prolongati on or of ST seg ment depression we re noted in any patient before or aft er trea tment. The number of fetuses had no effect on any of the se indices. Serum electrolytes were not affected by treatment . CONCLUSIONS: Maternal EKGs de monstrated no arrythmias or ischemic changes. Since s.q. admini stration of betamimctics requires lower doses than IV infusion, it may reduce hypopcrfusi on of the subendocardium and the refore avoid cardi ac ischemia.
Transcript of 521 Maternal and Fetal Cardiovascular Effects of Intravenous Adenosine
Vo lume 168 N umbe r I , Part 2
519 THE EFFECT OF EPIDURAL ANALGESIA ON THE FETAL ECG WAVEFORM. A. Gordonx, M.P. UmstadX, K W Murohyx, K. Phillipsx, A.D. Cameron, J. Flemingx. The Queen Mother's Hospital, Glasgow, Scotland. OBJECTIVE: To assess the ellect of epidural analgesia on the fetal ECG waveform. STUDY DESIGN: The fetal ECG waveform of 8 mothers receiving lumbar epidural analgesia with 0.25% bupivacaine were recorded with a computarised letal ECG monitor (STAN, Cinventa, Sweden). The fetal ECG complexes were analyzed for 20 minutes prior to epidural administration and for 40 minutes afterwards. The PR-interval and T/QRS ratios were measured at 5 minutes intervals. Confidence intervals analysis was used to assess the significance of differences between the mean values. RESULTS: Of the 8 fetuses studied, 5 demonstrated a significant rise in the T/QRS ratio following epidural analgesia, 2 showed a fall and the other remained unchanged. The effect of epidural analgesia on the PRinterval was variable; it was prolonged in 4 cases and shortened in the other 4 cases . CONCLUSIONS: The administration of epidural analgesia appears to significantly increase the T/QRS ratio 01 the fetal ECG waveform but has a variable effect on the PR-interval. Further evaluation is required.
520 EPIDURAL ANALGESIA AND OPERATIVE DELIVERIES. !: ~x, G Eglinton. T Tomaix, Y Shinx. Dept's. Ob/Gyn and Anesth, Georgetown University, Washington, D.C. OBJECTIVE: The objective of the study was to investigate the relationship between epidural analgesia in labor and non-spontaneous delivery. The null hypothesis was that operative deliveries occurred with similar frequency among panurients delivering with and without epidural analgesia. STUDY DESIGN: Medical records were reviewed for 1218 consecutive obstetric deliveries identified by computer listing provided by the medical records department. After exclusion of all patients with planned cesarean or induction of labor, attempted labor after prior cesarean delivery. multiple gestation. or nonstandard epidural regimens. 695 records were evaluable. Variables usually thought to be clinically important in their effect on mode of delivery were investigated via univariate parametric and nonparametric analyses. as appropriate . After these independent comparisons, the statistically significant variables were each tested using univariate logistic regression. Variables that remained both statistically and clinically significant were then tested in a multivariate logistic regression analysis to detennine which variables predicted the greatest relative risks of non-spontaneous delivery. RESULTS: Epidural analgesia, nulliparity, and oxytocin augmentation were associated with increased risk of operative vaginal delivery (odds ratios = OR 8.3 [confidence interval = CI 3.1 - 22.21, 3.0 [CI 1.7 . 5.11 , 3.0 [CI \.6 - 5.91, respectively). Cervical dilation> 3 em on admission was associated with a decreased risk (OR 0.26 [CIO.\3 - 0.5)). Epidural analgesia and nUlliparity were associated with an increased risk of cesarean delivery (OR 4.4 [CI 2.3 . 8.41. OR 2.6 [CI 1.6 - 4.21, respectively). CONCLUSIONS: Using a mult.ivariate analysis to control for confounding variables, among clinical\y significant factors evaluated, epidural analgesia was most strongly associated with non-spontaneous and cesarean delivery. This relationship warrants further investigation.
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SPO Abstracts 439
MATERNAL AND FETAL CARDIOVASCULAR EFFECTS OF INTRAVENOUS ADENOSINE. B. MasonX
, D. Ogunyemi X, O. PunlaX
, B. I(oos. Dept. Ob/Gyn, UCLA, Los Angeles, CA. OBJECTIVE: To study the cardiovascular and blood gas effects of maternal adenosine (ADO) infusion on the ewe and fetus. STooY DESIGN: Two sets of experiments were performed wi th 5 gravid ewes (0.8 term) in each group . Under chronic cond i t ions , 200ug/kg/min ADO was infused v i a the femoral vein of the ewes as either a single bolus or continuous 60 minute i nfusion. Blood pressure (BP), heart rate (HR), arterial blood gas es (ABG) and hemoglobin concentrations (Hb) were mon ; tored in both the ewe and the fetus. All data was analyzed us ing two- way analysis of variance. RESULTS: During the boluses, there was a transient fall in maternal HR foll owed by a brief rise in HR (mean 23.16 bpn) with retu r n to baseline values within 1 minute after the bolus (p<. OO 1) . Maternal diastolic BP showed a brief transient fall at the same t ime (mean 19.5±4_9 nmHg); p<.OO1). There was no si gnif icant change in maternal sys tolic BP, ABG, Hb, and fetal BP, HR, and Hb were not affected. During the continuous infus ions , there was a significant ri se i n maternal HR (mean 38.13 bpm; p<.OOI) and a significant fall in diastolic BP (mean 20.4. 10.7 nmHg; p<.OOI) both of which were sustained throughout the infusion. Maternal Hb increased significantly during the infusion but maternal systolic BP, ABG, and fetal HR, BP, ABG, and Hb were unchanged . A.ll changes returned to base l ine after infusions were discontinued . CONCLUSION : Al th ough intravenous acininistration of adenosine t o p regnant ewes causes significant changes in maternaL BP, HR , and Hb, the changes are brief and do not significanUy affect the cardiovascular or respiratory performance of the fetus. (Supported by HD 18478)
522 ELECTROCARDIOGRAPHIC ABNORMALITIES WITH SUBCUTANEOUS TERBUTALINE PUMP THERAPY. M. Alvarez, c.J. Lockwood, A. Ghidini, M. Paidas, J. Stone, R.L. Berkowitz, L. Lynch. Mt. Sinai School of Medicine, New York, NY. OBJECTIVE: Intravenous (IV) beta mimetic therapy for preterm labor has been associated with myocardial infarction and electrocardiographic (EKG) abnormalities. Since subcutaneous (s.q .) betamimetic therapy via a pump has been proposed as an alternative to IV tocolysis, we evaluated the m aternal EKG respo nse to s.q. terbutaline pump therapy. STUDY DESIGN: Consecutive con senting patients (n=1 8) admitted with preterm labor were placed on an EKG Holter mo nito r prior to therapy. Terbutaline S04 was administered as the initial tocolytic therapy via a s.q . pump at a basal dosage of 0.05 mg/hr with boluses of 0.25 mg every 4 hrs. An average of 48 hours of EKG recording were analyzed by paired t-tests. RESULTS: The mean maternal age and gestational age were 31 years and 27 weeks, respectively, with 61 .1 % Singleton, 22.00/0 twin and 16.7% triplet gestations. There were no differences in the mean number of premature ventricula r c ontractions (3 and 3.5, p=<J.8), or in the mean heart rale (127 and 136 bpm, p=O.l) before and after treatment, respectively. More cardiac pauses> 1 sec were present after treatment (7.0 vs. 0.4, p=<J.02) . However, no episodes of Qr interval prolongatio n or of ST segment depression were noted in any patient before or after treatment. The number of fetuses had no effect on any of these indices. Serum electroly tes were not affected by treatment. CONCLUSIONS: Maternal EKGs de monstrated no arrythmias or ischemic changes. Since s.q. administration of betamimctics requires lower doses than IV infusion, it may reduce hypopcrfusion of the subendocardium and therefore avoid cardiac ischemia.
