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.     

“GIOSAT”: a tool to assess CanMEDS competencies during simulated crises

Purpose

Our objective was to develop and evaluate a Generic Integrated Objective Structured Assessment Tool (GIOSAT) to integrate Medical Expert and intrinsic (non-medical expert) CanMEDS competencies with non-technical skills for crisis simulation.

Methods

An assessment tool was designed and piloted using two pediatric anesthesia scenarios (laryngospasm and hyperkalemia). Following revision of the tool, we used previously recorded videos of anesthesia residents (n = 50) who managed one of two intraoperative advanced cardiac life support (ACLS) scenarios (ventricular tachycardia or ventricular fibrillation). Four independent trained raters, blinded to the residents’ level of training, analyzed the video recordings using the GIOSAT scale. Inter-rater reliability was calculated using intraclass correlations (ICCs) for single raters (single measure) and the average of the four raters (average measure), and construct validity was investigated by correlating GIOSAT scores with postgraduate year of residency (PGY).

Results

Total GIOSAT scores for the ACLS scenarios had single measure ICCs of 0.62 and average measure ICCs of 0.85. Inter-rater reliability was substantial for both Medical Expert and intrinsic competencies (single measure ICCs 0.69 and 0.62, respectively; average measure ICCs 0.90 and 0.82, respectively). We found significant correlations between PGY level and total GIOSAT score (r = 0.36; P = 0.011) and between PGY level and Medical Expert competencies (r = 0.42; P = 0.003); however, correlations were not found between PGY level and intrinsic CanMEDS competencies (r = 0.24; P = 0.09).

Conclusion

Inter-rater reliability of the total GIOSAT scores using four trained raters was substantial. Significant correlation between PGY and (i) total GIOSAT score and (ii) Medical Expert competencies supports construct validity. Evidence of validity was not obtained for intrinsic CanMEDS competencies.     

Molecular Staging of Surgical Margins in Oral Squamous Cell Carcinoma Using Promoter Methylation of p16INK4A, Cytoglobin, E-cadherin, and TMEFF2

Background

Local recurrence in oral squamous cell carcinoma (OSCC) despite clear surgical margins may indicate the presence of residual, sub-microscopic disease. Molecular assessment of surgical margins may provide a greater prognostic sensitivity compared to histopathology. We aimed to determine whether promoter methylation in deep and mucosal resection margins can predict recurrence in OSCC.

Methods

Forty-eight consecutive OSCC cases were recruited and a 5 mm³ tumor sample plus 5 deep and 5 mucosal margin samples were snap frozen. Clinical, pathological, adjuvant therapy, and outcome data were recorded. Tumors were informative if >5 % promoter methylation was found for ≥1 of 4 genes using qMSP. Margins were declared molecularly positive if >1 % promoter methylation was found in any margin.

Results

Thirty (63 %) of 48 cases were methylation informative. Mucosal margin samples were largely positive for methylation (26 of 30, 87 %), indicating the presence of field cancerization. Methylation at ≥1 gene promoters in ≥1 deep margin correlated with the presence of close/involved mucosal margins (P = 0.027) and increased pT status (P = 0.027) but not the status of deep margins, recurrence, or survival.

Conclusions

The current gene panel did not add prognostic information to histopathological reporting of resection margins. Future efforts should concentrate on improving gene selection, informativity, and assay performance in the patient group with intermediate indications for adjuvant therapy.     

Single‐stage application of a novel decellularized dermis for treatment‐resistant lower limb ulcers: Positive outcomes assessed by SIAscopy,laser perfusion,and 3D imaging,with sequential timed histological analysis

We present results of an original clinical study investigating efficacy of a decellularized dermal skin substitute (DCD) as part of a one‐stage therapeutic strategy for recalcitrant leg ulcers. Twenty patients with treatment‐resistant ulcers underwent hydrosurgical debridement, after which DCD was applied and covered with negative pressure dressings for 1 week. Participants were reviewed on seven occasions over 6 months. 3D photography, full‐field laser perfusion imaging, spectrophotometric intracutaneous analysis, and sequential biopsies were used to monitor healing. Mean ulcer duration and surface area prior to DCD placement were 4.76 years (range 0.25–40 years) and 13.11 cm² (range 1.06–40.75 cm²), respectively. Seventy percent of ulcers were venous. Surface area decreased in all patients after treatment (range 23–100%). Mean reduction was 87% after 6 months, and 60% of patients healed completely. Wound bed hemoglobin flux increased significantly 6 weeks after treatment (p = 0.005). Histological and immunohistochemical analysis confirmed progressive DCD integration with colonization by host fibroblasts, lymphocytes, and neutrophils, resulting in fibroplasia, reepithelialisation, and angiogenesis, with correlating raised CD31, collagen I, and collagen III levels. Subgroup analysis showed differing cellular behavior depending on wound duration, with delayed angiogenesis, reduced collagen deposition, and smaller reductions in surface area in ulcers present for over 1 year. The stain intensities of immunohistochemical markers including fibronectin, collagen, and CD31 differed depending on depth from the wound surface and presence of intact epithelium. DCD safely produced significant improvement in treatment‐resistant leg ulcers. With no requirement for hospital admission, anesthetic, or autogenic skin grafting, this treatment could be administered in hospital and community settings.     

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.