Controlled exposures to air pollutants and risk of cardiac arrhythmia.

BACKGROUND: Epidemiological studies have reported associations between air pollution exposure and increases in cardiovascular morbidity and mortality. Exposure to air pollutants can influence cardiac autonomic tone and reduce heart rate variability, and may increase the risk of cardiac arrhythmias, particularly in susceptible patient groups. OBJECTIVES: We investigated the incidence of cardiac arrhythmias during and after controlled exposure to air pollutants in healthy volunteers and patients with coronary heart disease. METHODS: We analyzed data from 13 double-blind randomized crossover studies including 282 participants (140 healthy volunteers and 142 patients with stable coronary heart disease) from whom continuous electrocardiograms were available. The incidence of cardiac arrhythmias was recorded for each exposure and study population. RESULTS: There were no increases in any cardiac arrhythmia during or after exposure to dilute diesel exhaust, wood smoke, ozone, concentrated ambient particles, engineered carbon nanoparticles, or high ambient levels of air pollution in either healthy volunteers or patients with coronary heart disease. CONCLUSIONS: Acute controlled exposure to air pollutants did not increase the short-term risk of arrhythmia in participants. Research employing these techniques remains crucial in identifying the important pathophysiological pathways involved in the adverse effects of air pollution, and is vital to inform environmental and public health policy decisions.

Are head bandages required post-pinnaplasty?

A best evidence topic in ear, nose and throat surgery was written according to a structured protocol. The question addressed was: In patients who are undergoing pinnaplasty for prominent ears, does the use of post-operative head bandages as compared to not using post-operative head bandages improve clinical outcomes? A total of 121 papers were identified using the reported search protocol, of which five articles represented the best evidence to answer the clinical question. The authors, journal, date and country of publication, patient group studied, study type, relevant outcomes and results of these papers are tabulated. All five studies showed that no advantage exists in using head bandages with patients who have undergone pinnaplasty. Four of the five studies concluded that head bandages should not be utilised at all, whereas two of the five studies suggested that there is little reason to use head bandages after the first 24 h post-pinnaplasty. Therefore, the clinical bottom line is that provided the pinnaplasty result is good at time of surgery, there is reasonable evidence to suggest that head bandages have no effect on complications or patient satisfaction, so at best they are unnecessary and at worst, their physical drawbacks may actually outweigh any of their perceived benefits.