Research news in brief

Prescribing opioids: how long?

Findings from a US analysis published in JAMA Surgery suggest that the optimal length of opioid pain prescriptions is 4–9 days for general surgery procedures, 4–13 days for women’s health procedures and 6–15 days for musculoskeletal procedures. The study included more than 200 000 patients who underwent common surgical procedures. As rates of opioid prescribing have increased dramatically in recent years, the overprescription of pain medications has been implicated as a driver of the opioid epidemic and the associated increases in overdose deaths in the US. It is estimated that as many as 259 million opioid prescriptions were issued in 2012 – four times the number prescribed in 1999. Researchers from the Harvard Medical School used the US Department of Defense Military Health System Data Repository to identify individuals who had undergone one of eight common surgical procedures between January 2005 and September 2014 and had not previously used opioids. Of the 215 140 individuals who underwent a procedure within the study timeframe, and received and filled at least one prescription for opioid pain medication within 14 days of their procedure, 19% received at least one refill prescription. The median prescription lengths were 4 days for appendectomy and gallbladder removal, 5 days for inguinal hernia repair, 4 days for hysterectomy, 5 days for mastectomy, 5 days for anterior cruciate ligament repair and rotator cuff repair and 7 days for discectomy. The early nadir (the initial prescription duration associated with the lowest modelled risk of refill) in the probability of refill was at an initial prescription of 9 days for general surgery procedures (probability of refill, 10.7%), 13 days for women’s health procedures (probability of refill, 16.8%) and 15 days for musculoskeletal procedures (probability of refill, 32.5%).

Choice in exercise may lead to healthier eating

Researchers at the University of Western Australia have found that people who have no choice in the exercise they do are more likely to eat unhealthy food afterwards. The study, published in Medicine and Science in Sports and Exercise, found that those who had the ability to choose what exercise they engaged in enjoyed the session more and made healthier food choices. The study involved 58 men and women, with half given free choice about their exercise session. The other half, who were matched on variables such as sex, age, height, weight and fitness, were told they had to exercise under conditions chosen by someone else. The exercise choices given to participants included the mode of exercise (bike or treadmill), intensity and duration (between 30 and 60 minutes), the time of commencement, and the option to listen to music of their choosing. After the session, participants were provided a buffet-style breakfast that included a variety of healthy and unhealthy foods, while unwittingly being monitored by researchers. Natalya Beer from the University of Western Australia’s School of Human Sciences said that taking away choice during exercise seemed to increase the likelihood of people eating unhealthy foods afterwards. “We saw that participants who had their exercise chosen for them consumed almost double the amount of energy from unhealthy foods compared with those who had a choice,” Ms Beer said. “Unsurprisingly, we also found that giving people choice in their exercise session resulted in them having higher levels of enjoyment and perceived value, which may encourage them to continue to be healthy and active. There is strong evidence that the behaviours we are seeing may be a result of conscious processing, such as licensing. That is, the justification of rewarding a healthy behaviour with an unhealthy behaviour. Choose exercise you enjoy and you might feel less of an urge to reward yourself with unhealthy food when you finish.”

New technique to aid bladder cancer diagnosis

A new automated computer technique, developed by researchers at the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics at Macquarie University, is able to significantly aid in the diagnosis of bladder cancer. The technique, which allows suspect lesion images to be quickly and effectively analysed and then classified for cancer risk, has been reported in Urologic Oncology. “What we’ve done is develop a computer program to carry out an automated analysis of cystoscopy images,” said lead author, Dr Martin Gosnell. Cystoscopy is one of the most reliable methods for diagnosing bladder cancer explained Dr Gosnell. “Images are taken of the bladder and its insides for suspicious lesions during a routine clinical patient evaluation.” The issue, said Dr Gosnell, is that the clinician examining the initial images makes a visual judgement based on their professional expertise as to the next steps of action that should be undertaken, such as the need to take a biopsy for subsequent pathological analysis. “Potential errors and unnecessary further interventions may result from the subjective character of this initial visual assessment. What we’ve done is to create an automated image analysis technique that can identify tissue and lesions as either high risk or minimal risk. This is beneficial on multiple levels. Following the analysis, high risk diagnoses can be followed up more closely as a matter of urgent priority. Alternately, minimal risk lesions can be identified early in the diagnostic process, reducing the number of referrals or biopsies that need to take place.” Professor at Macquarie University, Ewa Goldys, Deputy Director of the Australian Research Council Centre of Excellence for Nanoscale BioPhotonics, and senior author on the research article said that the results from the automated system were extremely promising. “Using our innovative computer program, 100% of the cancerous images were detected. And all benign lesions were also successfully identified.”

Maternal smoking worsens neurological outcomes for babies

Scientists investigating the underlying mechanism causing hypoxic-ischaemic injury in mice have found possible links between maternal smoking and cerebral palsy. Hypoxic-ischaemic injury caused by blood and oxygen shortage to the brain reduces the wellbeing of the cellular “powerhouse” mitochondria, resulting in oxidative stress. This leads to increased cell death in the offspring’s brain. Hypoxic-ischaemic encephalopathy is reported to occur in approximately 6 per 1000 term newborns and may lead to neurological consequences, such as cerebral palsy and seizures. Researchers from the University of Technology Sydney, the University of Sydney and the University of NSW, used mouse models to show that maternal smoking affects the functioning of mitochondrial cells responsible for powering the body’s biological processes. The research showed that mouse pups with high levels of oxidative stress in the brain are more likely to develop functional disorders. “We found that pups from smoking mothers are clumsier at adolescent age, have less strength in their limbs, are more anxious and have poor memory function, which may affect their learning ability,” said Dr Chen. In particular, the learning ability is worsened if the pups had hypoxic-ischaemic injury. A potential preventive strategy may be to provide mothers with antioxidant supplementation during pregnancy. Previous studies carried out by this research team found the antioxidant L-carnitine given to pregnant mothers exposed to cigarette smoke may improve the health outcomes of kidneys and respiratory system in offspring. The research was published in Frontiers in Molecular Neuroscience.

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