Incidence of persistent postoperative opioid use in patients undergoing ambulatory surgery: a retrospective cohort study

The opioid crisis remains a major public health concern. In ambulatory surgery, persistent postoperative opioid use is poorly described and temporal trends are unknown. A population-based retrospective cohort study was undertaken in Ontario, Canada using routinely collected administrative data for adults undergoing ambulatory surgery between 1 January 2013 and 31 December 2017. The primary outcome was persistent postoperative opioid use, defined using best-practice methods. Multivariable generalised linear models were used to estimate the association of persistent postoperative opioid use with prognostic factors. Temporal trends in opioid use were examined using monthly time series, adjusting for patient-, surgical- and hospital-level variables. Of 340,013 patients, 44,224 (13.0%, 95%CI 12.9-13.1%) developed persistent postoperative opioid use after surgery. Following multivariable adjustment, the strongest predictors of persistent postoperative opioid use were pre-operative: utilisation of opioids (OR 9.51, 95%CI 8.69-10.39); opioid tolerance (OR 88.22, 95%CI 77.21-100.79); and utilisation of benzodiazepines (OR 13.75, 95%CI 12.89-14.86). The time series model demonstrated a small but significant trend towards decreasing persistent postoperative opioid use over time (adjusted percentage change per year -0.51%, 95%CI -0.83 to -0.19%, p = 0.003). More than 10% of patients who underwent ambulatory surgery experienced persistent postoperative opioid use; however, there was a temporal trend towards a reduction in persistent opioid use after surgery. Future studies are needed that focus on interventions which reduce persistent postoperative opioid use.

Regional anaesthesia quality indicators for adult patients undergoing non-cardiac surgery: a systematic review

Improvement in healthcare delivery depends on the ability to measure outcomes that can direct changes in the system. An overview of quality indicators within the field of regional anaesthesia is lacking. This systematic review aims to synthesise available quality indicators, as per the Donabedian framework, and provide a concise overview of evidence-based quality indicators within regional anaesthesia. A systematic literature search was conducted using the databases MEDLINE, Embase, CINAHL and Cochrane from 2003 to present, and a prespecified search of regional anaesthesia society websites and healthcare quality agencies. The quality indicators relevant to regional anaesthesia were subdivided into peri-operative structure, process and outcome indicators as per the Donabedian framework. The methodological quality of the indicators was determined as per the Oxford Centre for Evidence-Based Medicine's framework. Twenty manuscripts met our inclusion criteria and, in total, 68 unique quality indicators were identified. There were 4 (6%) structure, 12 (18%) process and 52 (76%) outcome indicators. Most of the indicators were related to the safety (57%) and effectiveness (19%) of regional anaesthesia and were general in nature (60%). In addition, most indicators (84%) were based on low levels of evidence. Our study is an important first step towards describing quality indicators for the provision of regional anaesthesia. Future research should focus on the development of structure and process quality indicators and improving the methodological quality and usability of these indicators.

Examining the effect of the injury definition on risk factor analysis in circus artists

A secondary data analysis of a prospective cohort study was conducted to explore how different definitions of injury affect the results of risk factor analyses. Modern circus artists (n=1281) were followed for 828,547 performances over a period of 49 months (2004-2008). A univariate risk factor analysis (age, sex, nationality, artist role) estimating incidence rate ratios (IRR) with 95% confidence intervals (95% CI) was conducted using three injury definitions: (1) medical attention injuries, (2) time-loss injuries resulting in ≥1 missed performances (TL-1) and (3) time-loss injuries resulting in >15 missed performances (TL-15). Results of the risk factor analysis were dependent on the injury definition. Sex (females to male; IRR=1.13, 95% CI; 1.02-1.25) and age over 30 (<20 years to >30 years; IRR=1.37, 95% CI; 1.07-1.79) were risk factors for medical attention injuries only. Risk of injury for Europeans compared with North Americans was higher for TL-1 and TL-15 injuries compared with medical attention injuries. Finally, non-sudden load artists (low-impact acts) were less likely than sudden load artists (high-impact acts) to have TL-1 injuries, but the risk of medical attention injuries was similar. The choice of injury definition can have effects on the magnitude and direction of risk factor analyses.

Plastic Flow in Rollers Loaded above the Yield Point

The plastic flow which occurs when two cylinders are rolled in line contact at loads exceeding the yield point has been examined. It has been found to consist of a circumferential movement of the surface in the rolling direction accompanied in some circumstances by radial corrugation. The resistance to rolling and distribution of pressure in the contact have been measured and the results are compared with the theoretical predictions of Merwin and Johnson in their accompanying paper (1)†.

Drosophila homolog of the myotonic dystrophy-associated gene, SIX5, is required for muscle and gonad development

SIX5 belongs to a family of highly conserved homeodomain transcription factors implicated in development and disease. The mammalian SIX5/SIX4 gene pair is likely to be involved in the development of mesodermal structures. Moreover, a variety of data have implicated human SIX5 dysfunction as a contributor to myotonic dystrophy type 1 (DM1), a condition characterized by a number of pathologies including muscle defects and testicular atrophy. However, this link remains controversial. Here, we investigate the Drosophila gene, D-Six4, which is the closest homolog to SIX5 of the three Drosophila Six family members. We show by mutant analysis that D-Six4 is required for the normal development of muscle and the mesodermal component of the gonad. Moreover, adult males with defective D-Six4 genes exhibit testicular reduction. We propose that D-Six4 directly or indirectly regulates genes involved in the cell recognition events required for myoblast fusion and the germline:soma interaction. While the exact phenotypic relationship between D-Six4 and SIX4/5 remains to be elucidated, the defects in D-Six4 mutant flies suggest that human SIX5 should be more strongly considered as being responsible for the muscle wasting and testicular atrophy phenotypes in DM1.

Structure, mapping and expression of the human gene encoding the homeodomain protein, SIX2

Vertebrate genes with sequence similarity to the Drosophila homeobox gene, sine oculis (so), constitute the SIX family. There is notable expression of members of this family in anterior neural structures, and several SIX genes have been shown to play roles in vertebrate and insect development, or have been implicated in maintenance of the differentiated state of tissues. Mutations in three of these genes in man (SIX5, SIX6 and SIX3) are associated with severe phenotypes, and therefore, the cloning of other human genes from this family is of interest. We have cloned and characterised the gene that encodes human SIX2, elucidated its gene structure and conducted expression studies in a range of tissues. SIX2 is widely expressed in the late first-trimester fetus, but has a limited range of expression sites in the adult. The expression pattern of SIX2 and its localisation to chromosome 2p15-p16 will be of use in assessing its candidacy in human developmental disorders.

Cardowan coal mine explosion: experience of a mass burns incident

A coal mine explosion 1700 feet (516 m) underground and two miles (3.2 km) from the pit head resulted in 40 casualties. Two hours elapsed between the explosion and the arrival of patients at hospital. Six patients suffered mechanical injuries, only one of which was life threatening. Thirty six suffered burns; in 18 over 15% of the total body surface area was affected. Nineteen patients had a mild respiratory upset requiring oxygen treatment. The average length of inpatient stay in those admitted was 24 days. Early assessment and treatment in the accident and emergency department was relatively simple because of the large proportion of burn injuries. Lack of communication between site and hospital made administration of the disaster difficult.