The effect of low concentrations versus high concentrations of local anesthetics for labour analgesia on obstetric and anesthetic outcomes: a meta-analysis

Introduction

The influence that different concentrations of labour epidural local anesthetic have on assisted vaginal delivery (AVD) and many obstetric outcomes and side effects is uncertain. The purpose of this meta-analysis was to determine whether local anesthetics utilized at low concentrations (LCs) during labour are associated with a decreased incidence of AVD when compared with high concentrations (HCs).

Methods

We searched PubMed, Ovid EMBASE, Ovid MEDLINE, CINAHL, Scopus, clinicaltrials.gov, and Cochrane databases for randomized controlled trials of labouring patients that compared LCs (defined as ≤ 0.1% epidural bupivacaine or ≤ 0.17% ropivacaine) of epidural local anesthetic with HCs for maintenance of analgesia. The primary outcome was AVD and secondary outcomes included Cesarean delivery, duration of labour, analgesia, side effects (nausea and vomiting, motor block, hypotension, pruritus, and urinary retention), and neonatal outcomes. The odds ratios (OR) or weighted mean differences (WMD) and 95% confidence intervals (CI) were calculated using random effects modelling. An OR < 1 or a WMD < 0 favoured LCs.

Results

Eleven studies met our criteria (eight bupivacaine and three ropivacaine studies), providing 1,145 patients in the LCs group and 852 patients in the HCs group for analysis of the primary outcome. Low concentrations were associated with a reduction in the incidence of AVD (OR = 0.70; 95% CI 0.56 to 0.86; P < 0.001). There was no difference in the incidence of Cesarean delivery (OR 1.05; 95% CI 0.82 to 1.33; P = 0.7). The LCs group had less motor block (OR 3.9; 95% CI 1.59 to 9.55; P = 0.003), greater ambulation (OR 2.8; 95% CI 1.1 to 7.14; P = 0.03), less urinary retention (OR 0.42; 95% CI 0.23 to 0.73; P = 0.002), and a shorter second stage of labour (WMD ?14.03; 95% CI ?27.52 to ?0.55; P = 0.04) compared with the HCs group. There were no differences between groups in pain scores, maternal nausea and vomiting, hypotension, fetal heart rate abnormalities, five-minute Apgar scores, and need for neonatal resuscitation. One-minute Apgar scores < 7 favoured the HCs group (OR 1.53; 95% CI 1.07 to 2.21; P = 0.02), and there was more pruritus in the LCs group (OR 3.36; 95% CI 1.00 to 11.31; P = 0.05).

Conclusion

When compared with HCs of local anesthetics, the use of LCs for labour epidural analgesia reduces the incidence of AVD. This may be due to a reduction in the amount of local anesthetic used and the subsequent decrease in motor blockade. We therefore recommend the use of LCs of local anesthetics for epidural analgesia to optimize obstetric outcome.     

A randomized study of open-flap surgery of 32 intrabony defects with and without adjunct bovine bone mineral treatment

Background: Bovine bone mineral (BBM) is extensively used as a filler material in periodontal reconstructive surgery of intrabony defects. Data are mostly available on the combined use of BBM with other biomaterials. The aim of this study is to evaluate healing after open‐flap debridement (OF) of intrabony periodontal defects alone or with adjunct treatment with BBM. Methods: After initial treatment, 32 patients with 32 intrabony periodontal defects participated in the study. Full‐thickness flaps were raised and root surfaces and defects were debrided. Patients were then randomly assigned to treatment groups, either OF alone or combined with defect fill with BBM, and followed in a strict postoperative maintenance care program for 12 months. Results: At 12 months, a mean ± SE gingival recession of 1.1 ± 0.3 mm in OF and 0.9 ± 0.4 mm in BBM occurred. Probing depth reduction was 4.0 ± 0.5 mm in OF and 3.2 ± 0.7 mm in BBM. Gain in clinical attachment level was 2.8 ± 0.6 mm in OF and 2.3 ± 0.8 mm in BBM. Probing bone level was reduced by 2.7 ± 0.7 mm in OF and 1.8 ± 1.1 mm in BBM. None of the above parameters showed significant intergroup differences. In contrast, radiographic defect depth change was significantly greater in BBM (3.4 ± 2.3 mm) than in OF (1.9 ± 1.7 mm). Conclusions: Both treatments resulted in improved periodontal conditions. The adjunctive use of BBM in this study did not enhance the clinical result compared to OF alone.     

Azoospermia factor deletions in varicocele cases with severe oligozoospermia

BACKGROUND: Varicocele is the most common cause of male infertility. The etiology and pathophysiology of varicocele are multifactorial. When low sperm counts are associated with varicocele, varicocelectomy can partially restore spermatogenesis and fertility. Few recent studies have reported that in some varicocele cases, there may be an associated genetic etiology. Presence of a genetic factor like azoospermia factor microdeletions may lead to irreversible spermatogenic arrest in these cases, but very few reports support these findings. However, it is still not understood why some cases improve after varicocelectomy and why some cases show no improvement in semen parameters postoperatively. AIM: It is important to distinguish varicocele cases from Yq microdeletions as these cases have irreversible testicular damage and thus carry a poor prognosis after varicocelectomy. SETTINGS: Research and Referral tertiary care hospital. Design: Prospective study. MATERIALS AND METHODS: Seventy-two infertile men with varicocele were referred for Yq microdeletion analysis from the infertility clinic of AIIMS and Army Research and Referral Hospital. Genomic DNA was isolated from blood and polymerase chain reaction microdeletion screening was done in these cases to determine the presence or deletion of AZF loci. RESULTS: In this study 7 (9.7%) varicocele cases harbored Yq microdeletion. The sperm count in cases which harbored Yq microdeletion was significantly lower than in cases without Yq microdeletion. CONCLUSION: Varicocele cases with Yq microdeletion do not show improvement in semen parameters post-varicocelectomy. Detection of Yq microdeletion determines prognosis and future management in such cases.