Maternal positioning affects fetal heart rate changes after epidural analgesia for labour

• Published in: Canadian journal of anesthesia Vol. 40; no. 12; pp. 1136 - 1141
• Main Authors: PRESTON, R, CROSBY, E. T, KOTARBA, D, DUDAS, H, ELLIOTT, R. D
• Format: Journal Article
• Language: English
• Published: Toronto, ON Canadian Anesthesiologists' Society 01-12-1993
• Subjects: Abdominal surgery. Urology. Gynecology. Obstetrics; Analgesia, Epidural - nursing; Analgesia, Obstetrical - nursing; Anesthesia; Anesthesia depending on type of surgery; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Aorta - physiology; Biological and medical sciences; Blood Pressure - physiology; Bupivacaine - administration & dosage; Female; Fetal Distress - etiology; Fetal Monitoring; Heart Rate, Fetal - drug effects; Heart Rate, Fetal - physiology; Humans; Hypotension - physiopathology; Labor, Obstetric; Medical sciences; Nerve Block; Pain - prevention & control; Posture - physiology; Pregnancy; Pressure; Prospective Studies; Supine Position - physiology; Time Factors; Uterus - blood supply; Venae Cavae - physiology; Human; Arrhythmia; Position; Cardiovascular disease; Labour; Obstetrics; Analgesia; Regional anesthesia; Heart disease; Extradural administration; Complication; Female; Fetus; Delivery
• ISSN: 0832-610X; 1496-8975
• DOI: 10.1007/BF03009602

Adverse fetal heart rate (FHR) changes suggestive of fetal hypoxia are seen in patients with normal term pregnancies after initiation of epidural block for labour analgesia. It was our hypothesis that, in some parturients, these changes were a consequence of concealed aortocaval compression resulting in decreased uterine blood flow. We expected that the full lateral position compared with the wedged supine position would provide more effective prophylaxis against aortocaval compression. To test our hypothesis we studied the role of maternal positioning on FHR changes during onset of epidural analgesia for labour. Eighty-eight ASA Class I or II term parturients were randomized into two groups: those to be nursed in the wedged supine position and those to be nursed in the full lateral position during induction of an epidural block. External FHR monitoring was employed to assess the fetal response to initiation of labour epidural analgesia. Epidural catheters were sited with the parturients in the sitting position and the patients then assumed the study position. After a negative test dose, a standardized regimen of bupivacaine 0.25% was employed to provide labour analgesia. The quality and efficacy of the block were assessed using VAS pain scores, motor block scores and sensory levels. The results demonstrated that there was no difference in the quality of analgesia provided nor in the incidence of asymmetric blocks. There was no difference in the observed incidence of FHR changes occurring during the initiation of the epidural block.