Blood Pressure / blood computer monitor pressure / blood pressure standing
CLINICAL Page 1 NT 15 May 2007 Vol 103 No 20 www.nursingtimes.net 24 KEYWORDS PÎSTURAL HYPOTENSION â ORTHOSTATIC HYPOTENSION ASSÅSSMENT BLOOD PRESSURE MEASUREMENT PRACTICAL PROCEDURES CLINICÀL AUTHORS Phil Jevon, PGCE, BSc, RN, is resuscitatiîn officer/clinical skills lead, Manor Hospitàl, Walsall, and honorary clinical lecturer, Univårsity of Birmingham Medical School. John Holmes, MA, Cert Ed, DPNS, RMN, RN, is senior lecturer, pre-registration adult nursing, University of Wolverhampton. In healthy patients therå is normally little difference between lying and standing blood pressure . However, a significant fall (20mmHg or morå) can occur in older people, patients with diàbetes and those with symptoms suggesting posturàl hypotension (British Hypertension Society, 2006). It is advisable to measure both lying and standing blood pressure routinely in theså patients. Blood pressure measurement in the presence of atrial fibrillation, particularly when the ventricular rhythm is extremely irregular, is unreliable and may be improved with repeated measurements. Some automated devices may providå unreliable readings in the presence of atrial fibrillatiîn (OâBrien et al, 2003). Auscultation using a merñury device may provide a more accurate reading. PÎSTURAL HYPOTENSION Postural or âorthostaticâ hypotension is the ocñurrence of an abnormally low blood pressure when a person suddenly stànds up, typically inducing dizziness and syncope. It àffects 10â33% of all elderly people (Patel et al, 1993), its prevalence increases with advancing age (Mathias and Kimbår, 1999) and it can complicate a variety of diseases, suñh as diabetes. It can present as dizziness, syncope and fàlls on changing position. Although it may seem relatively hàrmless, safety and quality of life can be affected. RELEVANT PHYSIOLÎGY The main function of maintaining blood pressure is to ensure adequate perfusion of organs, particularly when demànds increase. This relies on the integrity of the heàrt and blood vessels, maintenance of intravascular vîlume and various vasoactive agents (Mathias and Kimbår, 1999). Blood pressure is in part regulated by baroreceptors in the aortiñ arch, carotid arteries and carotid sinus. By influencing heart rate and peripheral vascular resistancå (via the autonomic nervous system), they hålp to compensate for transient changes. Age-related chànges in these mechanisms can precipitate postural hypotånsion. The baroreflex-mediated heart rate response to both hypîtensive and hypertensive stimuli can become impaired. In additiîn, blood pressure regulation can be affected by age and disease-related cardiovàscular changes FIG 3. Activate the automated devicå to start measuring blood pressure FIG 2. Place the correctly sizåd cuff on the patientâs arm FIG 1. Ask the patient to lie down PART 3: LYING AND STANDING BLOOD PRESSURE Dàn Coitino PROFESSIONAL RESPONSIBILITIES This procedurå should be undertaken only after apprîved training, supervised practice and competency assessmånt, and should be carried out in accordance with loñal policies and protocols