Examining the Duration of Carryover Effect in Patients With Chronic Pain Treated With Spinal Cord Stimulation (EChO Study):An Open, Interventional, Investigator-Initiated, International Multicenter Study

Objectives: Spinal cord stimulation (SCS) is a surgical treatment for severe, chronic, neuropathic pain. It is based on one to two lead(s) implanted in the epidural space, stimulating the dorsal column. It has long been assumed that when deactivating SCS, there is a variable interval before the patient perceives the return of the pain, a phenomenon often termed echo or carryover effect. Although the carryover effect has been problematized as a source of error in crossover studies, no experimental investigation of the effect has been published. This open, prospective, international multicenter study aimed to systematically document, quantify, and investigate the carryover effect in SCS. Materials and Methods: Eligible patients with a beneficial effect from their SCS treatment were instructed to deactivate their SCS device in a home setting and to reactivate it when their pain returned. The primary outcome was duration of carryover time defined as the time interval from deactivation to reactivation. Central clinical parameters (age, sex, indication for SCS, SCS treatment details, pain score) were registered and correlated with carryover time using nonparametric tests (Mann-Whitney/Kruskal-Wallis) for categorical data and linear regression for continuous data. Results: In total, 158 patients were included in the analyses. A median carryover time of five hours was found (interquartile range 2.5;21 hours). Back pain as primary indication for SCS, high-frequency stimulation, and higher pain score at the time of deactivation were correlated with longer carryover time. Conclusions: This study confirms the existence of the carryover effect and indicates a remarkably high degree of interindividual variation. The results suggest that the magnitude of carryover may be correlated to the nature of the pain condition and possibly stimulation paradigms. Clinical Trial Registration: The Clinicaltrials.gov registration number for the study is NCT03386058.</p

Neonatal morbidity after spontaneous labor onset prior to intended cesarean delivery at term : a cohort study

Introduction: We aimed to investigate if labor onset before planned cesarean delivery (CD) affects the risk of neonatal admission, respiratory distress, or neonatal infectious morbidity. Material and methods: Our cohort included singleton term pregnant women with intended CD who delivered at Aarhus University Hospital from 1990 to 2012. Two groups of women were identified: women with intended CD performed before labor (nonlabor CD) and women with intended CD performed after spontaneous labor onset (labor-onset CD); in both groups there was no other maternal or fetal medical indication for an immediate CD or for early-term CD scheduling. Data were stratified in early-term (37–38 weeks) and full-term (39–40 weeks) deliveries. The main outcome measures were neonatal admission, respiratory distress and neonatal infectious morbidity. Results: Among 103 919 live births, 5071 deliveries were nonlabor CDs and 731 were labor-onset CDs. Compared to nonlabor CD, labor-onset CD was associated with similar risks of neonatal admission and respiratory distress, both at early and full term, but with a two- to three-fold increased risk of newborn septicemia or antibiotic treatment at early term. Labor onset at early term was associated with a lower risk of maternal blood loss of more than 500 mL, but with a higher risk of postoperative antibiotic treatment and endometritis. Conclusions: Labor onset before planned CD was not associated with a decrease in neonatal respiratory morbidity, but may be associated with increased risks of neonatal infection

Vitamin D and the risk of dystocia: A case-control study.

BackgroundDystocia is one of the most common causes of cesarean section in nulliparous women. Studies have described the presence of vitamin D receptors in the myometrium, but it is still unclear whether vitamin D affects the contractility of the smooth muscles. We therefore aimed to determine the association between the vitamin D serum level at labor and the risk of dystocia.MethodWe conducted a case-control study between January 2012 and June 2017. Cases were primiparous women, with spontaneous onset of labor, who gave birth by cesarean section due to dystocia. Controls were primiparous women with a spontaneous vaginal delivery. We included 60 women (30 cases and 30 controls) in the analysis. The differences between cases and controls were assessed using chi-squared test for categorical variables and two-sample t-test or unequal t-test for continuous variables, as appropriate, after evaluation of whether they followed the normal distributions.ResultsThe mean serum 25-hydroxyvitamin D concentrations were 53.1nmol/l (95%CI; 45.2 to 60.9) among cases and 69.9nmol/l (95%CI; 57.5 to 82.4) among controls (P = 0.02). The mean plasma parathyroid hormone levels were 2.25 pmol/l and 2.38, respectively (P = 0.57). Even though 78% of all women reported taking a minimum of 10μg/day of vitamin D throughout pregnancy, 43% had vitamin D insufficiency, defined as serum 25-hydroxyvitamin D levels below 50nmol/l.ConclusionsIn a Danish group of women having a cesarean section due to dystocia, we found decreased vitamin D levels

Seasonal variation of dystocia in a large Danish cohort.

BACKGROUND: Dystocia is one of the most frequent causes of cesarean delivery in nulliparous women. Despite this, its causes are largely unknown. Vitamin D receptor (VDR) has been found in the myometrium. Thus, it is possible that vitamin D affects the contractility of the myometrium and may be involved in the pathogenesis of dystocia. Seasonal variation of dystocia in areas with distinct seasonal variation in sunlight exposure, like Denmark, could imply that vitamin D may play a role. This study examined whether there was seasonal variation in the incidence of dystocia in a Danish population. METHOD: We used information from a cohort of 34,261 nulliparous women with singleton pregnancies, spontaneous onset of labor between 37 and 42 completed gestational weeks, and vertex fetal presentation. All women gave birth between 1992 and 2010 at the Department of Obstetrics and Gynecology, Aarhus University Hospital, Skejby. Logistic regression combined with cubic spline was used to estimate the seasonal variation for each outcome after adjusting for calendar time. RESULTS: No evidence for seasonal variation was found for any of the outcomes: acute cesarean delivery due to dystocia (p = 0.44); instrumental vaginal delivery due to dystocia (p = 0.69); oxytocin augmentation due to dystocia (p = 0.46); and overall dystocia (p = 0.91). CONCLUSION: No seasonal variation in the incidence of dystocia was observed in a large cohort of Danish women. This may reflect no association between vitamin D and dystocia, or alternatively that other factors with seasonal variation and influence on the occurrence of dystocia attenuate such an association

Seasonal variation of dystocia.

<p>The solid line represents the estimated seasonal variation of dystocia after adjusting for time-trend, with 95% CI (dashed line). Dots represent the relative risk (RR) obtained by grouping the season into months. Some monthly point estimates (dots) are outside the CIs of the seasonal variation curve, and one is significant, (marked with a triangle).</p