Measurement of Blood Pressure: Issues and Challenges Sadhana Bhagwat, NPO WCO India 13 December 2018

Silent killer Most hypertensive people have no symptoms Under-diagnosis Under-treatment

Hypertension Prevalence, Awareness, Treatment China: Age 35-75. Liu J, Lancet. 2017 Dec 9;390(10112):2549-2558

Most with Hypertension in India Are Not Aware and Hence Not treated Barely 1 in 10 of the 218 million adults with hypertension in India have it under control 74M 60M Despite the heavy burden of illness and death from hypertension, many countries have been slow to respond. Just over half with HTN know they have it and just 1 in 7 globally have it under control. These proportions are significantly higher in LMICs. Yet HTN is probably the easiest to treat and effective treatment is available and can be relatively inexpensive. 24M <11% Roy A et al. BMJ Open. 2017;7:e015639. Data for Delhi National Capital Region weighted and applied nationally.

WHO Guidance on Hypertension FDC, Blood Pressure Device, Self care Best buys, Global action plan CVD, risk factors Advocacy Surveillance Capacity Monitoring Diagnosis Assess CVD risk Innovations Essential Medicines and Technology Treatment Protocol Data System Technical package Risk stratification -STEP survey -WHS plus Invest 1 USD on drug therapy and counselling to high CVD risk, return 3.29 USD -Screen

Diagnosis Confirmation of hypertension: after two visits ideally 1 to 4 weeks apart Systolic blood pressure on both days is ≥140 mmHg and/or Diastolic blood pressure on both days is ≥90 mmHg Patients with SBP ≥160 mmHg or DBP ≥100 mmHg may be indicated for immediate treatment based on one assessment High blood pressure, according to the WHO-ISH guidelines, includes both hypertension (defined as 140/90 mmHg or above) and ``high normal'' (between 130/85 mmHg and 140/90 mmHg). The WHO-ISH guidelines class optimal blood pressure as less than 120/80 mmHg, 105/60

Essential technology (device and lab) Blood pressure measurement device, Stethoscope Weighing scales Measuring tapes Urine albumin strips Urine ketones test strips Glucometer, blood glucose test strips Blood cholesterol, electrolyte, creatinine, ECG BP> From Mercury, to Aneroid, to Electronic. Cost of essential technology, point of care, validation -Affordable technology blood pressure measuring devices for low resource settings, WHO 2005 Challenges at PHC at low resource settings

Diagnosis confirmation Diagnosis and treatment of hypertension Diagnosis confirmation Detection Prolonged Treatment

Challenges in Diagnosis Three sources of error in the measurement of blood pressure (AHA) Observer bias Faulty equipment Failure to standardize the technique of measurement Diagnosis confirmation

Three sources of error in the measurement of blood pressure (AHA) Observer bias Faulty equipment Failure to standardize the technique of measurement

Common errors…. Raise the pressure to 30mm above pulse palpation Lower at 2mm/sec (faster rate: lower SBP and higher DBP) Terminal digit preference: rounding off to the zero: over estimation *Office blood pressure measurement practices among community health providers (medical and paramedical) in northern district of India; Bishav Mohan a,*, Naved Aslam a, Upma Ralhan b, Sarit Sharma et al, India Heart Journal 6 6 ( 2 0 1 4 ) 4 0 1 -4 0 7

Three sources of error in the measurement of blood pressure (AHA) Observer bias Faulty equipment Failure to standardize the technique of measurement

Common errors….* The best equipment???? Calibration interval

Three sources of error in the measurement of blood pressure (AHA) Observer bias Faulty equipment Failure to standardize the technique of measurement

Common errors…. Supporting the arm: lower SBP/DBP by 11 and 12mm as compared to unsupported arm Right cuff sizes: if small (obese people) SBP can rise by 8mm Resting the patient: food, cold weather, stress, activity, coffee, tobacco Auscultation: 1st appearance of sound: systolic Complete disappearance of sound: diastolic

Common errors…. Minimum two readings Sitting is better than supine: 3mm SBP raised and 3mm DBP lowered in supine Centre of the bladder: Heart level: Increases if above, decreases if below that

WHO Guidance

Objectives of the workshop Present the available guidelines and preliminary progress on guidance updating Solicit practical country-level inputs from representatives on the most suitable devices for different levels of health care Purchasing and maintaining blood pressure devices at different levels of health care provision