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Table of Contents
Blood Pressure
Blood pressure (section: physical state) was measured in all Lifelines participants aged 8 years and older during:
- 1A Visit 1 (n = ~163.000, including ~11.000 children)
- 2A Visit 1 (n = ~119.000)
Blood pressure was measured with the participant seated. The size of the cuff was chosen according to the arm circumference of the participant. For systolic and diastolic blood pressure, the average of the final three readings was recorded.
Device
At 1A and 2A, blood pressure was measured automatically using the DinaMap PRO100 or DinaMap PRO100V2 critikon-dinamap-pro-op-manual.pdf.
At 3A, blood pressure was measured automatically using the ABPM 7100.
Contra-indications
Blood pressure was not taken in case of:
- Lymph node surgery on the right breast or armpit
- Complaints of fluid accumulation in the right arm
- No blood pressure measurement on the side of a dialysis shunt
Protocol
- Participant is seated and informed about the procedure. Participant is requested to sit still, to keep quiet, and to not move the arm.
- Research nurse informs about contraindications: recent axillary lymph node dissection; dialysis arterial-venous shunt; complaints of quick fluid retention/edema in the arm.
- If none are present, measurement is taken at the bare upper right arm. If any are present (in the right arm) the blood pressure measurement is taken at the left upper arm. This registered by the research nurse.
- The cuff, standard size M, is placed on the bare upper arm. For proper fit of the cuff check if the end of the cuff falls within the two indicated lines. If this is not the case use a smaller (S) or a larger (L or XL) cuff to avoid errors.
- The arrow on the cuff is placed over the branchial artery, 2.5 cm above the elbow crease. It should fit snugly without being too tight.
- Dinamap/ABPM is connected to a PC and recordings are processed automatically, the research nurse checks if readings are complete and additionally takes notes of the measurements.
- Cuff is removed. And if requested by participant, the last recording is given.
Calculation
The following methods were used to calculate the systolic blood pressure (SBP) and diastolic blood pressure (DBP). Mean blood pressure is calculated when SBP and DBP are both successfully recorded.
| If | Then |
|---|---|
| the difference between the two last successive SBP/DBP measurements is ≤ 15 mmHg | calculate the mean SBP/DBP by taking the average of the two last successive blood pressures |
| the difference between the two last successive SBP/DBP measurements is > 15 mmHg | the average SBP/DBP is calculated by taking the average of the last and the previous measurements. For example if measurement 9 and 10 differs more than 15 mgHg, the average is taken from measurement 8 and 10 |
| there are no two successive SBP/DBP measurements with a difference ≤ 15 mmHg, but there are at least two measurements with a difference ≤ 15 mmHg | mean SBP/DBP is calculated using all available measurements |
| there are only two SBP/DBP measurements, but the difference is > 15 mmHg | the last measurement is regarded as the mean SBP/DBP |
| there is only one SBP/DBP measurement | the measurement is regarded as the mean SBP/DBP |
| none of the above | the mean SBP/DBP is reviewed and calculated manually by the medical professional (visual inspection of data) |
Variables
The following variables were measured:
