| MadSci Network: Anatomy |
Tumi, The description of the procedure for blood pressure measurement at the US National Library of Medicine at http://www.nlm.nih.gov/medlineplus/ency/article/003398.htm#How%20the% 20test%20is%20performed doesn't mention a specific arm for the test; niether does the Kendall Regional Medical Center in Florida, at http://ehc.healthgate.com/GetContent.asp?siteid=F2252160-8E31-11D3-AD16- 00508B91A0DD&docid=/dsp/bpmeasure or, in fact, any reference I could come across. It's interesting to note that the diagram at the Kendall Medical Center shows the test being performed on the right arm. I found some reasons given for the left arm preference in non-medical literature, the most-cited one being that the left bracial artery is purported to be closer to the heart than the right. Some careful checking in a few anatomy books and a discussion with a medical examiner pretty much precluded that as being the real answer. I talked with an old associate of mine who is a critical care nurse, and asked whether a reading in the right or left arm is more accurate: she said that the arm choice doesn't matter if the patient is healthy and has good general circulation. She herself tends to use the right arm because she's left-handed and it's easier for her to operate the cuff when it's on the patient's right arm. I suspect this is the biggest reason for the left- arm preference you've observed: most people are right-handed, and a right- handed doctor or nurse will find it easier to use the cuff on a patient's left arm. I hope this was helpful!
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