INTRAVENOUS NITROGLYCERIN TO RELIEVE INTRAPARTUM FETAL DISTRESS RELATED TO UTERINE HYPERACTIVITY - A PROSPECTIVE OBSERVATIONAL STUDY

During a l-yr period, we evaluated prospectively the use of nitroglyce rin (NTG) to relieve severe intrapartum fetal distress related to uter ine hyperactivity. Sixty to ninety micrograms of NTG were injected int ravenously (IV) within 2-5 min after onset of severe fetal distress af ter oxygen administration, left lateral decubitus, and discontinuation of any ongoing oxytocin infusion (62%) had failed to resolve the feta l heart rate abnormality. A second dose (60 or 90 mu g) was used 2-3 m in later as required. NTG was completely effective in 22 cases (fetal distress resolution within 4-5 min with restoration of normal uterine activity) and partially but sufficiently effective in the remaining 2 cases (fetal distress resolution within 4-5 min with residual mild ute rine hyperactivity). However, a second dose was required for nine part urients (38%). Six parturients (25%) developed hypotension 2 min after the first NTG injection, with a mean nadir of 93.2 mm Hg (minimum 85 mm Hg). Hypotension was always rapidly reversed with a small single do se of ephedrine (4.5-6 mg). In conclusion, we found small doses (60-18 0 mu g) of IV NTG to be associated with resolution of severe fetal dis tress related to uterine hyperactivity along with negligible side effe cts.