Accidental dural puncture during labor analgesia and obstetric outcomes in nulliparous women.

BACKGROUND: The effect of accidental dural puncture during labor epidural analgesia on obstetric outcomes remains unexplored. In this retrospective cohort study, we tested the hypothesis that accidental dural puncture is associated with prolonged second stage of labor. METHODS: Anesthetic and obstetric data from nulliparous parturients who suffered an accidental dural puncture at term labor (n=89) during the years 2006-2012 were compared with randomly selected parturients with uncomplicated epidural analgesia (n=232). The primary outcome was the proportion of parturients with prolonged second stage of labor: secondary outcomes were the proportion of instrumented and cesarean deliveries. Statistical analysis included student t-test for continuous variables, chi-square test for binary variables, and logistic regressions for associations between accidental dural puncture and outcomes. RESULTS: Demographic and obstetric characteristics of parturients were comparable except for a non-significant increase in prolonged second stage of labor in the accidental dural puncture group (27% vs. 17%, P=0.06). After adjusting for known potential confounders, multivariate logistic regression analyses revealed a significant association between accidental dural puncture and prolonged second stage of labor (adjusted risk ratio [aRR] 1.99, 95% CI 1.04 to 3.82; P=0.037). This was not accompanied by an increase in instrumented (aRR 0.57, 95% CI 0.27 to 1.21; P=0.15) or cesarean delivery (aRR 1.83, 95% CI 0.89 to 3.77; P=0.10). CONCLUSION: Accidental dural puncture during labor analgesia was associated with prolonged second stage of labor in nulliparous parturients. Prospective studies are needed to assess the relationship between the quality of neuraxial block after accidental dural puncture and obstetric outcomes.

Effect of neuraxial technique after inadvertent dural puncture on obstetric outcomes and anesthetic complications.

BACKGROUND: The aim of this study was to evaluate labor and delivery outcomes in parturients with inadvertent dural puncture managed by either insertion of an intrathecal catheter or a resited epidural catheter. METHODS: This was a retrospective cohort review of 235 parturients who had an inadvertent dural puncture during epidural placement over a six-year period. The primary outcome was the proportion of women with a delayed second stage of labor. Secondary outcomes were the proportion of cesarean deliveries, the proportion of cases resulting in post-dural puncture headache, and the incidence of failed labor analgesia. RESULTS: Baseline characteristics such as age, body mass index and parity were similar between the two groups. Among the 236 cases of inadvertent dural puncture, 173 women (73%) had an intrathecal catheter placed while 63 women (27%) had the epidural catheter resited. Comparing intrathecal with epidural catheters, there was no observed difference in the proportion of cases of prolonged second stage of labor (13% vs. 16%, P=0.57) and the overall rate of cesarean deliveries (17% vs. 16%, P=0.78). However, we observed a lower rate of post-dural puncture headache in women who had cesarean delivery compared to vaginal delivery (53% vs. 74%, P=0.007). A greater proportion of failed labor analgesia was observed in the intrathecal catheter group (14% vs. 2%, P=0.005). CONCLUSION: The choice of neuraxial technique following inadvertent dural puncture does not appear to alter the course of labor and delivery. Cesarean delivery decreased the incidence of post-dural puncture headache by 35%. Intrathecal catheters were associated with a higher rate of failed analgesia.

Combinatorial molecular optimization of cement hydrates.

Despite its ubiquitous presence in the built environment, concrete's molecular-level properties are only recently being explored using experimental and simulation studies. Increasing societal concerns about concrete's environmental footprint have provided strong motivation to develop new concrete with greater specific stiffness or strength (for structures with less material). Herein, a combinatorial approach is described to optimize properties of cement hydrates. The method entails screening a computationally generated database of atomic structures of calcium-silicate-hydrate, the binding phase of concrete, against a set of three defect attributes: calcium-to-silicon ratio as compositional index and two correlation distances describing medium-range silicon-oxygen and calcium-oxygen environments. Although structural and mechanical properties correlate well with calcium-to-silicon ratio, the cross-correlation between all three defect attributes reveals an indentation modulus-to-hardness ratio extremum, analogous to identifying optimum network connectivity in glass rheology. We also comment on implications of the present findings for a novel route to optimize the nanoscale mechanical properties of cement hydrate.

Establishing an obstetric neuraxial service in low-resource areas.

The proportion of laboring women utilizing neuraxial techniques for labor analgesia has steadily increased over the past decades in North America, the UK and parts of Europe. Anesthesiologists in many other countries may want to introduce an obstetric neuraxial service but may lack the knowledge and experience necessary to ensure its safety. The focus of this article is to address the necessity, benefit and challenges of establishing such a service in a resource-limited environment. Even successful financial institutions may be considered resource-limited if critical components necessary for an obstetric neuraxial service are missing due to either perceived unimportance or non-availability. There is a need to deploy a culture of safety by ensuring the availability of resuscitation equipment, developing protocols and training, fostering communication among members of the care team and initiating quality-control measures. Patient education and satisfaction are additional key components of a successful service. Even in financially low-resource settings, proper safety measures must be adopted so that the neuraxial procedure itself does not contribute to morbidity and mortality. A viable and safe neuraxial service can be developed using innovative strategies based on local constraints.