title: Effect of patient positioning on toe pressure measurement using noninvasive vascular testing.
abstract: OBJECTIVE
  Interpretation of digital pressure in the assessment of healing potential for diabetic foot disease has become common because of the potential for false elevation with the ankle-brachial index. However, the specific testing protocol for segmental Doppler examinations and photoplethysmography require patients to be in the supine position, with the lower limbs at heart level, in order to minimise the effect of hydrostatic pressure. This may be difficult in many patients with lower extremity pathology, particularly those who are nonambulatory, with painful wounds, or with orthopnea. In these situations, the noninvasive vascular test may be performed with the patient in a more comfortable position, which may include sitting in a wheelchair with the leg in a dependent position. The objective of this investigation was to evaluate the effect of patient positioning on measurement of the digital pressure.
  
  
  METHODS
  Hallux pressures were measured in 20 healthy volunteers in 3 variable positions of limb dependency.
  
  
  RESULTS
  The mean±standard deviation of digital pressure for subjects while lying supine with the limb at heart level was 103.5±26.0 mmHg (the recommended position for performance of the test), while sitting upright with the limb level on the table was 130.6±27.9 mmHg (+26.2%, p<0.0001) and sitting upright with the limb in a dependent position was 169.8±30.8 mmHg (+64.1%, p<0.0001).
  
  
  CONCLUSIONS
  On the basis of these results, we conclude that patient positioning has a significant effect on measurement of digital pressure.
authors: Resident, Temple University Hospital Podiatric Surgical Residency Program, Philadelphia, USA.
authors: Laura E
authors: LE
authors: Sansosti
authors: Resident, Temple University Hospital Podiatric Surgical Residency Program, Philadelphia, USA.
authors: Michael D
authors: MD
authors: Berger
authors: Student, Temple University School of Podiatric Medicine, Philadelphia, USA.
authors: Michael A
authors: MA
authors: Gerrity
authors: Manager, Temple University Hospital Vascular Laboratory, Philadelphia, USA.
authors: Patrick
authors: P
authors: Kelly
authors: Associate Professor, Department of Podiatric Surgery, Temple University School of Podiatric Medicine, Philadelphia, USA.
authors: Andrew J
authors: AJ
authors: Meyr
mesh_terms: D000328:Adult; D055109:Ankle Brachial Index; D017719:Diabetic Foot / Q000503:physiopathology*; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D056888:Patient Positioning; D017156:Photoplethysmography; D011312:Pressure; D014034:Toes / Q000098:blood supply*
keywords: diabetic foot; patient positioning; photoplethysmogram; toe-brachial index; vascular calcification