Highlights of this issue

CMAJ 2000;162:1549

Between April 1996 and January 1999, 69 patients with acute ischemic stroke received intravenously administered tissue plasminogen activator (tPA) through the Calgary Regional Stroke Program. Over 1 year, only 6% of the patients admitted with stroke were given tPA; the main reasons for not treating more patients were thought to be a delay in arrival at hospital and difficulty establishing the time of symptom onset. Michael Hill and colleagues outline the essential 5 Rs of acute stroke care — recognition, reaction, response, reveal and reperfusion — and report on the barriers, outcomes and lessons learned during the first 3 years of the program. They emphasize the need for public education about the symptoms of stroke.

• Withholding life-sustaining treatment: Are adolescents competent to make these decisions? [Review]

Should adolescents be given the authority to make health care decisions? Christopher Doig and Ellen Burgess review the arguments, including the idea of "proportionality," which states the more serious the health outcome, the higher the level of competency required. The authors identify a clear ethical and legal foundation for permitting competent adolescents to decide whether they will accept life-sustaining medical treatment.

• Chest pain with nondiagnostic electrocardiogram in the emergency department: a randomized controlled trial of two cardiac marker regimens [Research]

Eugene Dagnone and colleagues conducted a randomized controlled trial involving 296 patients with chest pain and a nondiagnostic electrocardiogram to investigate whether the addition of 2 new cardiac markers (baseline cardiac troponin I and myoglobin and 2-hour myoglobin) to the standard panel (baseline creatine kinase [CK] and CK MB fraction) would result in improved clinical decisions in the emergency department. They found no difference in the length of stay in the emergency department between patients randomly assigned to have the standard panel of cardiac markers and those assigned the enhanced panel. Fewer patients in the latter group were admitted to the cardiology service (46% v. 54%), but the difference was not significant (8.1%, 95% confidence interval –3.3 to 19.5). At 30 days the proportions of patients with a diagnosis of recurrent angina or an acute myocardial infarction were similar in the 2 groups. The authors conclude that the additional markers did not substantially change clinical management.

• Folate and vitamin B₁₂ status of women in Newfoundland at their first prenatal visit [Research]
• Folic acid: the opportunity that still exists [Commentary]

It is well known that the intake of folate and multivitamins in the periconceptional period reduces the risk of several congenital anomalies. James House and colleagues measured serum and red blood cell (RBC) folate levels in 1424 women in Newfoundland at their first prenatal visit. According to the serum levels less than 4% of the women had deficient or indeterminate folate levels; however, the RBC levels, which may be more reflective of the time of neural tube closure, indicated that 24% had deficient or indeterminate levels. In an accompanying commentary Judith Hall laments the opportunity many of us miss by failing to take daily supplements of folic acid.

The blacklegged tick Ixodes scapularis is a principal vector of Borrelia burgdorferi, the spirochete that causes Lyme disease. Satyendra Banerjee and colleagues report that, of 139 I. scapularis ticks collected from Ontario dogs between 1997 and 1998, 9 were carrying B. burgdorferi. Some of the dogs were in areas where the tick species is not endemic. In an accompanying commentary Ian Barker and Robbin Lindsay explain that these were likely "adventitious" ticks that arrived in immature stages on birds migrating from endemic areas and that their density in the environment is quite low.

© 2000 Canadian Medical Association or its licensors