Research Outline and Report

Measuring Blood Pressure In The Lowest Extremities

Sidney Aung

Biomed Science Research Program

Mr.Hyke

Abstract

My research explores the validity and practical uses of measuring blood pressures in the lower extremities instead of the more commonly known medical procedure of measuring blood pressure in the upper extremities. Situations in which measuring blood pressure in the lower extremities would be useful and practical in patients where upper extremity blood pressures cannot be measured accurately in cases such as external compression, tumors, and presences of AV shunts. I tested 15 participants for their upper and lower extremities twice, and my results were valid with my hypothesis. The difference between the upper and lower extremity blood pressures was less than 10 mm Hg. This shows that the method I used for measuring BP in the lower extremities was acceptable, and reliable.

Purpose

The purpose of my experiment is to compare the results of measuring blood pressure in the lower extremities to the results of measuring it in the upper extremities.

Background Information

Blood pressure is theforce of blood against the walls of yours arteries. Blood pressure is recorded as two numbers: the systolic number as the heart beats and the diastolic number as the heart rests.The device used to measure blood pressure is known as the sphygmomanometer. It has an inflatable cuff attached to restrict blood flow and a mercury manometer is used to measure the pressure. Values are read in “mm Hg.”Read with systolic number on top and diastolic number on bottom. Normal blood pressure is 90-120 mmHg systolic and 60-80 mmHg diastolic. Blood pressure usually falls and rises during the day and High blood pressure(hypertension) is when blood pressure stays elevated over time. High blood pressure is 140/90 mm Hg and above. High blood pressure often has no warning signs. Anyone, regardless of race, age, or gender can develop HBP and once hypertension develops, it usually lasts a lifetime. Hypertension increases risk of heart/kidney diseases, and stroke. It is also associated with atherosclerosis and can cause congestive heart failure, and blindness. It is also usually accompanied with an increased risk of heart attack.

Hypothesis

My hypothesis is that the measurement of blood pressure in both the lower and upper extremities will essentially be the same or very close(within 10) if measured correctly.

Materials

Sphygmomanometer

Attached Cuff

Paper

Pencil

Participants(Age 16-20)

Procedure/methodology

Upper Extremities BP measuring:

Have participant sit upright in a chair with feet flat on floor and limbs uncrossed.

Arm rested on table to be at heart level.

place the cuff on bare upper arm, one inch above the bend of elbow.

Evenly tighten the cuff.

Take blood pressure twice and took average.

Lower Extremities BP measuring:

Have participant lay down flat in order for the leg to be at heart level.

Placed cuff on the leg.

Evenly tighten the cuff.

Take blood pressure twice and took average.

Data Collection/Results

	Upper extremities (diastolic/systolic)	Lower extremities (diastolic/systolic)
Participant 1	114.5/51.5 mmHg	121/63 mmHg
Participant 2	109/74 mmHg	126/69 mmHg
Participant 3	110.5/69 mmHg	103/41.5 mmHg
Participant 4	113.5/54.5 mmHg	125/54 mmHg
Participant 5	125/49 mmHg	130/37.5 mmHg
Participant 6	132.5/62 mmHg	129.5/53.5 mmHg
Participant 7	117.5/57 mmHg	125/49.5 mmHg
Participant 8	118/65.5 mmHg	127/46.5 mmHg

	Upper Extremities (diastolic/systolic)	Lower Extremities (diastolic/systolic)
Participant 9	121/65.5 mmHg	127/54 mmHg
Participant 10	129.5/49.5 mmHg	124.5/71 mmHg
Participant 11	110/62 mmHg	114/67.5 mmHg
Participant 12	127/74.5 mmHg	120.5/57.5 mmHg
Participant 13	120/63.5 mmHg	122.5/61.5 mmHg
Participant 14	119/62.5 mmHg	124.5/56 mmHg
Participant 15	122/62.5 mmHg	120.5/48 mmHg

The average blood pressure was 119.3 mmHg diastolic and 61.5 mmHg systolic for the upper extremities while the average was 116 mmHg systolic and 55.3 mmHg diastolic for the lower extremities.

Analysis

The data I collected from the participants and their respective blood pressure measurements demonstrated fascinating information to me. It showed that measuing blood pressure in the lower extremities of the body is not only practical, but efficient and reliable. I cannot say this for sure unless I perform future experiments that produce similar results, but from what I can infer, it is an efficient method of measuring blood pressure. This method can be used in hospitals and medical facilities and should be incoorporated in those institutes once further researched upon.

Conclusion

My hypothesis was correct, and the difference between the upper and lower extremity blood pressures was less than 10 mm Hg. This shows that the method I used for measuring BP in the lower extremities was acceptable, and reliable.

Possible Sources of Error

Incorrect positioning of participants

Irregular breathing

Talking/laughing/distractions

Adrenaline

Incorrect data input

Acknowledgements

I'd like to acknowledge Dr.Su Hline, family, friends and Mr hyke.

References

http://www.nhlbi.nih.gov/hbp/index.htmlpressure/MM00784

http://www.medicine.mcgill.ca/physio/vlab/cardio/back.htm

http://www.mayoclinic.com/health/how-to-measure-blood