Hamish Farquhar

Publications (2)13.82 Total impact

• Article: Systematic review of studies of the effect of hyperoxia on coronary blood flow.

  Hamish Farquhar, Mark Weatherall, Meme Wijesinghe, Kyle Perrin, Anil Ranchord, Mark Simmonds, Richard Beasley
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  ABSTRACT: International guidelines recommend the routine use of oxygen in the initial treatment of myocardial infarction, yet it is uncertain what effect this might have on physiologic and clinical outcomes. We undertook a systematic search of Medline, Cochrane Database of Systematic Reviews, EMBASE, and CINHAL using the key words "oxygen," "coronary blood flow," "hyperoxia," and "coronary circulation" to identify human studies involving a measure of coronary blood flow while breathing oxygen and room air. The primary outcome measure was coronary blood flow; secondary outcomes included coronary vascular resistance and myocardial oxygen consumption. From 2,072 potential publications, there were 6 studies from 4 publications that met the inclusion criteria, with 6 healthy subjects and 61 subjects with cardiac disease. It was not possible to undertake a meta-analysis due to methodological limitations. In the 6 studies, high-concentration oxygen therapy resulted in hyperoxia, with a range in mean Pao(2) of 273 to 425 mm Hg. Hyperoxia caused a significant reduction in coronary blood flow (mean change -7.9% to -28.9%, n = 6 studies). Hyperoxia caused a significant increase in coronary vascular resistance (mean change 21.5% to 40.9%, n = 4 studies) and a significant reduction in myocardial oxygen consumption (mean change -15.3% to -26.9%, n = 3 studies). Hyperoxia from high-concentration oxygen therapy causes a marked reduction in coronary blood flow and myocardial oxygen consumption. These physiologic effects may have the potential to cause harm and are relevant to the use of high-concentration oxygen therapy in the treatment of cardiac and other disorders.
  American heart journal 10/2009; 158(3):371-7. · 4.65 Impact Factor
• Article: The acetaminophen and asthma hypothesis 10 years on: A case to answer.

  Hamish Farquhar, Julian Crane, Edwin A Mitchell, Sally Eyers, Richard Beasley
  The Journal of allergy and clinical immunology 09/2009; 124(4):649-51. · 9.17 Impact Factor