Highlights

Do N95 respirators prevent infection?

N95 respirators may have a few advantages over ordinary surgical masks in experimental settings, but when it comes to helping health care workers avoid acquiring acute respiratory infections in clinical settings, they appear not to be superior. The authors of this systematic review and meta-analysis call for larger randomized controlled trials of better quality to help settle the question definitively. See Research, page 567

Management of low-grade prostate cancer

An examination of clinical data from one Canadian diagnostic centre shows that active surveillance has become an increasingly common management strategy for men with low-grade prostate cancer. See Research, page E141

ACE inhibitors versus ARBs in diabetic retinopathy

Patients with diabetic retinopathy who received either an angiotensin-converting-enzyme (ACE) inhibitor or an angiotensin II receptor blocker (ARB) experienced similar rates of death and major adverse cardiac events. This observational cohort study used population-based administrative data from Taiwan to compare 9769 patients who had received an ACE inhibitor within 90 days after a diagnosis of diabetic retinopathy between 2000 and 2010 with 9769 similar patients identified using propensity score matching who had received an ARB. Because ACE inhibitors and ARBs appear equally safe and effective in this context, treatment choices should be based on individual patient adherence and tolerance, say the authors. See Research, page E148

Screening for developmental delay

Although it may seem intuitive that we should be screening children for developmental delay, there is no evidence from randomized controlled trials that health outcomes are improved as a result of such screening. In this evidence-based guideline, the Canadian Task Force on Preventive Health Care recommends that we not screen children for developmental delay, but also cautions that clinicians should remain alert to missed age-appropriate developmental milestones. See Guidelines, page 579

Hypotension and cannabinoids in children

Two cases are reported of substantial hypotension developing after children undergoing treatment for cancer were given tetrahydrocannabinol–cannabidiol oil by their parents. With increased use of cannabinoids in children with cancer, the authors caution that there is little information on the dosing, safety and efficacy of these products. See Cases, page 596

Amyloid imaging for dementia in Canada

Amyloid imaging allows in vivo detection of amyloid plaques, a core pathologic feature of Alzheimer disease, with high sensitivity and specificity. Presently, amyloid imaging in Canada remains largely a part of clinical trials, but a ligand should soon be available for clinical purposes in Canada. In whom should this testing be considered? See Innovations, page 598

Diagnosing dementia

Dementia is a clinical diagnosis, but imaging and other modalities may be considered in situations where the diagnosis is uncertain. These include anatomic imaging, nuclear medicine brain scans and positron emission tomography. Cerebrospinal fluid biomarkers are currently used for investigational purposes only, say Wang and colleagues. See Five things to know …, page 603

Blue man syndrome

A 73-year-old man noticed progressive bluish skin discolouration, predominantly in sun-exposed areas, six years after starting amiodarone treatment for ventricular tachycardia. An uncommon adverse effect of amiodarone treatment, this skin discolouration is reversible with dose reduction or cessation of the drug, say Jolly and Klein. See Clinical images, page 604