Too tight to give birth? Assessment of pelvic floor muscle function in 277 nulliparous pregnant women

Introduction and hypothesis

Theoretically, tight or strong pelvic floor muscles may impair the progress of labor and lead to instrumental deliveries. We aimed to investigate whether vaginal resting pressure, pelvic floor muscle strength, or endurance at midpregnancy affect delivery outcome.

Methods

This was a prospective cohort study of women giving birth at a university hospital. Vaginal resting pressure, pelvic floor muscle strength, and endurance in 300 nulliparous pregnant women were assessed at mean gestational week 20.8 (±1.4) using a high precision pressure transducer connected to a vaginal balloon. Delivery outcome measures [acute cesarean section, prolonged second stage of labor (> 2 h), instrumental vaginal delivery (vacuum and forceps), episiotomy, and third- and fourth-degree perineal tear) were retrieved from the hospital’s electronic birth records.

Results

Twenty-three women were lost to follow-up, mostly because they gave birth at another hospital. Women with prolonged second stage had significantly higher resting pressure than women with second stage less than 2 h; the mean difference was 4.4 cmH₂O [95 % confidence interval (CI) 1.2–7.6], p?<?0.01, adjusted odds ratio 1.049 (95 % CI 1.011–1.089, p?=?0.012). Vaginal resting pressure did not affect other delivery outcomes. Pelvic floor muscle strength and endurance similarly were not associated with any delivery outcomes.

Conclusions

While midpregnancy vaginal resting pressure is associated with prolonged second stage of labor, neither vaginal resting pressure nor pelvic floor muscle strength or endurance are associated with operative delivery or perineal tears. Strong pelvic floor muscles are not disadvantageous for vaginal delivery.     

Local cooling reduces regional bone blood flow

Local cooling is very common after bone and joint surgery. Therefore the knowledge of bone blood flow during local cooling is of substantial interest. Previous studies revealed that hypothermia leads to vasoconstriction followed by decreased blood flow levels. The aim of this study was to characterize if local cooling is capable of inducing reduced blood flow in bone tissue using a stepwise‐reduced temperature protocol in experimental rabbits. To examine bone blood flow we utilized the fluorescent microsphere (FM) method. In New Zealand white rabbits one randomly chosen hind limb was cooled stepwise from 32 to 2°C, whereas the contra lateral hind limb served as control. Injection of microspheres was performed after stabilization of bone and muscle temperature at each temperature level. Bones were removed, dissected and fluorescence intensity was determined to calculate blood flow values. We found that blood flow of all cooled regions decreased relative to the applied external temperature. At maximum cooling blood flow was almost completely disrupted, indicating local cooling as powerful regulatory mechanism for regional bone blood flow (RBBF). Postoperative cooling therefore may lead to strongly decreased bone blood flow values. As a result external cooling has capacity to both diminish bone healing and reduce bleeding complications. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 31:1820–1827, 2013     

Abstracts 2013

Canadian Journal of Anesthesia/Journal canadien d'anesthésie -     

Inclusion of CYP3A5 genotyping in a nonparametric population model improves dosing of tacrolimus early after transplantation

Following organ engraftment, initial dosing of tacrolimus is based on recipient weight and adjusted by measured C₀ concentrations. The bioavailability and elimination of tacrolimus are affected by the patients CYP3A5 genotype. Prospective data of the clinical advantage of knowing patient's CYP3A5 genotype prior to transplantation are lacking. A nonparametric population model was developed for tacrolimus in renal transplant recipients. Data from 99 patients were used for model development and validation. A three‐compartment model with first‐order absorption and lag time from the dosing compartment described the data well. Clearances and volumes of distribution were allometrically scaled to body size. The final model included fat‐free mass, body mass index, hematocrit, time after transplantation, and CYP3A5 genotype as covariates. The bias and imprecision were 0.35 and 1.38, respectively, in the external data set. Patients with functional CYP3A5 had 26% higher clearance and 37% lower bioavailability. Knowledge of CYP3A5 genotype provided an initial advantage, but only until 3‐4 tacrolimus concentrations were known. After this, a model without CYP3A5 genotype predicted just as well. The present models seem applicable for clinical individual dose predictions but need a prospective evaluation.     

Long-term outcome of children treated with rituximab for idiopathic nephrotic syndrome

Background

Rituximab (RTX) has recently showed promising results in the treatment of steroid-dependent idiopathic nephrotic syndrome (SDNS).

Methods

This was a retrospective multicenter study of 18 children treated with RTX for SDNS, with a mean follow-up of 3.2 years. RTX was introduced because of side effects or relapses during therapy with immunosuppressive agents. The children received one to four infusions of RTX during the first course of treatment, and subsequent infusions were given due to CD19-cell recovery (CD19?>1 %; 54 % of children) or relapse (41 %), as well as systematically (5 %).

Results

Treatment with RTX maintained sustained remission without relapse in 22 % of patients and increased the duration of remission in all other patients. The time between two successive relapses was 9 months in the absence of re-treatment and 24.5 months when infusions were performed at the time of CD19-cell recovery. At the last follow-up, 44.5 % of patients were free of oral drug therapy. Of those still receiving oral drugs, all doses had been decreased. No serious adverse events occurred.

Conclusion

The results of this retrospective study confirm the efficacy and very good safety of RTX in the treatment of SDNS. The optimal therapeutic protocol seems to be a repeated single infusion at the time of CD19-cell recovery.     

Healing of osteotomy sites applying either piezosurgery or two conventional saw blades: a pilot study in rabbits

Purpose

The purpose of this study was to compare bone healing of experimental osteotomies applying either piezosurgery or two different oscillating saw blades in a rabbit model.

Methods

The 16 rabbits were randomly assigned into four groups to comply with observation periods of one, two, three and five weeks. In all animals, four osteotomy lines were performed on the left and right nasal bone using a conventional saw blade, a novel saw blade and piezosurgery.

Results

All three osteotomy techniques revealed an advanced gap healing starting after one week. The most pronounced new bone formation took place between two and three weeks, whereby piezoelectric surgery revealed a tendency to faster bone formation and remodelling. Yet, there were no significant differences between the three modalities.

Conclusions

The use of a novel as well as the piezoelectric bone-cutting instrument revealed advanced bone healing with a favourable surgical performance compared to a traditional saw.     

Impaired bone microarchitecture at the distal radius in older men with low muscle mass and grip strength: The STRAMBO study

The aim was to study the association between bone microarchitecture and muscle mass and strength in older men. Volumetric bone mineral density (vBMD) and bone microarchitecture were assessed in 810 men aged ≥60 years at the distal radius by high‐resolution peripheral computed tomography (HR‐pQCT). Areal bone mineral density (aBMD) and appendicular muscle mass (ASM) were assessed by dual‐energy X‐ray absorptiometry (DXA). Relative ASM of the upper limbs (RASM‐u.l.) was calculated as ASM of the upper limbs/(height)². Grip strength was measured by dynanometry. In multivariable models, men in the lowest RASM‐u.l. quartile had lower cross‐sectional area (CSA), cortical area (Ct.Ar), cortical thickness (Ct.Th), and trabecular area (Tb.Ar) at distal radius compared with men in the highest quartile. The trends remained significant after adjustment for grip strength. Men in the lowest quartile of the normalized grip strength (grip strength/[height]²) had lower aBMD, total vBMD, Ct.Ar, Ct.Th, Tb.vBMD, and Tb.N, and higher Tb.Sp and Tb.Sp.SD. The associations for Ct.Ar, total vBMD, Ct.Th, Tb.vBMD, and Tb.Sp remained significant after adjustment for RASM‐u.l. In the models including RASM‐u.l. and normalized grip strength, CSA and Tb.Ar were associated with RASM‐u.l. but not with the strength. Lower Ct.Th, Tb.vBMD, and Tb.N were associated with lower grip strength but not with RASM‐u.l. Lower Ct.Ar was associated with lower grip strength and with lower RASM‐u.l. In conclusion, in older men, low RASM‐u.l. and low grip strength are associated with poor cortical and trabecular microarchitecture partly independently of each other, after adjustment for confounders. © 2013 American Society for Bone and Mineral Research