There were no clinical benefits to administering phenylephrine as an infusion versus a bolus regimen. The bolus regimen maintained maternal arterial blood pressure closer to baseline in the initial minutes after spinal injection but this had no clinical benefits. The infusion regimen required a higher total dose of phenylephrine to maintain maternal arterial blood pressure at baseline during the predelivery period.

No abstract

Japan has seen significant developments in obstetric anesthesia in recent years, including the establishment of the Japanese Society of Obstetric Anesthesia and Perinatology. However, labor pain, which is one of the most important issues in obstetric practice, is still not treated aggressively. The rate of epidural administration for labor analgesia is very low in Japan as compared to other developed countries. Remifentanil has been used for labor analgesia, as part of general anesthesia for cesarean delivery, as well as for various fetal procedures around the world. Intravenous patient-controlled analgesia (IVPCA) with remifentanil is considered to be a reasonable option for labor pain relief. Several studies have demonstrated its efficacy with minimal maternal and neonatal adverse effects. On the other hand, reports of cases of maternal cardiac and respiratory arrest with remifentanil IVPCA within the past couple of years have redirected our attention to its safe use. Remifentanil IVPCA warrants one-to-one nursing monitoring, appropriate education of healthcare providers, continuous maternal oxygen saturation monitoring, end-tidal CO monitoring, and availability of both maternal and neonatal resuscitation equipment. This article provides an overview of knowledge and principles of using remifentanil IVPCA for labor analgesia and introduces its potential usage in Japan.

ESR spectra of the short-lived radicals of catechol and gallic acid formed by reaction with hydroxyl radical (HO • ) in acidic solution were measured using a dielectric mixing resonator and were compared with those formed by autoxidation in an alkaline solution. The triple triplet and triplet absorptions of catechol and gallic acid in alkaline solution showed that they were the phenoxy radicals and that the residual phenolic hydroxyl groups (φ-OH) were ionized. On the contrary, the lines were broad and unresolvable in acidic solution, suggesting that the radicals were exchanging between some limiting structures with a rate that affected the line shape. The radical is thought to be phenoxy formed by dehydrogenation with HO • , and the position of the unpaired electron can move to another φ-OH through a cationic radical structure as an intermediate. Thus, a simulation was performed assuming that the Bloch equation is applicable to some groups of the lines of the limiting structures. A method for the quantum-chemical analysis was developed, and the exchange rate and the hyperfine splitting constants were obtained from the best-fit spectra using a revised Marquardt method. The results suggest that polyphenols scavenge HO • using the φ-OHs, but it was impossible to determine which φ-OH was used from the ESR spectra because the structure was changing among a few structures.