What is the best device for ambulatory blood pressure (ABP) monitoring?

Best Device for Ambulatory Blood Pressure Monitoring

For ambulatory blood pressure monitoring (ABPM), validated oscillometric devices that have undergone independent validation according to recognized standards (AAMI or BHS) are the best choice, with specific preference for devices that provide comprehensive 24-hour data with minimal patient discomfort.

Device Selection Criteria

When selecting an ABPM device, healthcare providers should consider:

1. Validation status:

   • Only use devices that have been independently validated according to Association for the Advancement of Medical Instrumentation (AAMI) or British Hypertension Society (BHS) standards 1
   • A comprehensive list of validated monitors is available at www.dableducational.org 1

2. Technical specifications:

   • Oscillometric technology is preferred for most clinical applications 2
   • Device should measure every 15-30 minutes over a 24-hour period 1
   • Capability to store 50-100 readings 1
   • Memory function to prevent data fabrication 1
   • Software that allows customization of diurnal patterns 1

3. Patient comfort and compliance:

   • Lightweight design appropriate for smaller bodies 1
   • Proper cuff sizing (approximately 40% of mid-arm circumference) 1
   • Low noise level during inflation/deflation 3
   • Minimal sleep disturbance 3

Specific Device Recommendations

Based on the available evidence, the following devices have demonstrated good performance:

• Spacelabs 90217A: Validated device with good accuracy in both static and ambulatory conditions 4
• Mobil-O-Graph NG: Validated according to European Society of Hypertension criteria 5, with comparable accuracy to Spacelabs but better patient comfort 4, 3

Newer cuffless technologies are emerging with promising results:

• Wrist-worn photoplethysmography-based devices have shown comparable measurements to standard cuff-based ABPM with significantly less patient inconvenience 6
• The LiveOne wristband device has demonstrated high correlation with invasive arterial line measurements (r=0.91 for SBP, r=0.85 for DBP) 7

Clinical Interpretation Standards

For proper interpretation of ABPM data:

• Normal ABPM values 1:

  • Daytime: <135/85 mmHg
  • Nighttime: <120/70 mmHg
  • 24-hour: <130/80 mmHg

• Abnormal ABPM values 1:

  • Daytime: >140/90 mmHg
  • Nighttime: >125/75 mmHg
  • 24-hour: >135/85 mmHg

Common Pitfalls to Avoid

1. Inaccurate readings due to:

   • Inappropriate cuff size 2
   • Patient movement during measurement 2
   • Failure to maintain arm at heart level 1

2. Misinterpretation of data:

   • Incorrect day/night divisions not matching patient's actual sleep-wake cycle 1
   • Reliance on automated filters that may not be appropriate for all patients 1
   • Failure to account for activity levels during monitoring 1

3. Device-specific issues:

   • Different manufacturers use proprietary algorithms that can lead to variations in readings between devices (up to 10-15 mmHg) 2
   • Most oscillometric devices are not validated for use in atrial fibrillation 2
   • Some devices may underestimate MAP in older patients with stiff arteries 2

Conclusion

When selecting an ABPM device, healthcare providers should prioritize validated oscillometric devices that balance accuracy with patient comfort. The Mobil-O-Graph NG offers a good combination of accuracy and patient acceptance 4, 5, 3. For patients who find traditional cuff-based monitors too uncomfortable, newer cuffless wrist-worn technologies may offer a promising alternative with comparable accuracy 6, 7, though these require further validation before becoming the standard of care.