POSTURAL CHANGES IN BLOOD PRESSURE IN NORMOTENSIVE PERSONS

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POSTURAL CHANGES IN BLOOD PRESSURE IN NORMOTENSIVE

PERSONS

Mrunalini Kanvinde*, Dr. Vivek Nalgirkar, Rhea Sarkari, Milli Arora and Rebecca Wig

Lecturer in Physiology, Dr.D.Y.Patil Medical College, Nerul, Navi Mumbai.

ABSTRACT

Purpose – The primary purpose of this study is to observe the postural variation of blood pressure and to compare to find out error difference.

Blood pressure is a measure of cardiovascular reactivity reflecting

autonomic function. Short Term regulatory mechanism (Baroreceptor

reflex) is operated to maintain normal blood pressure. Pooling of blood

in lower extremities occur due to gravitational effects. It reduces

venous return and stroke volume with a fall in systolic blood pressure.

Material and Method –By keeping Inclusion and exclusion criteria, subjects selected for this study were 50 in number with age group 15 to

>55 years of both sex and they were categorized into four groups based

on their age. By taking position of the patient into consideration, blood pressure was recorded

in lying and standing posture. Error difference in blood pressure was found in standing

position by double recording. Questionnaires evaluated about smoking habits, medication use

and history of past illness. Statistical analysis was done by t-test. Result –From above study,

it was found that blood pressure varies in lying position than in standing position (p<0.01)

with less error in blood pressure recording (p<0.05). It was also found that both systolic

blood pressure and diastolic blood pressure increases in standing position(P<0.01)

Conclusion – Finally, it was concluded that in normotensive person, blood pressure varies according to posture of the person due to changes in hemodynamic, which is under the

control of central command through baroreceptors, blood pressure controlling body.

KEYWORDS: Systolic blood pressure, diastolic blood pressure, normotensive persons, baroreceptors.

Volume 5, Issue 9, 1498-1502. Research Article ISSN 2277– 7105

*Corresponding Author

Mrunalini Kanvinde

Lecturer in Physiology,

Dr.D.Y.Patil Medical

College, Nerul, Navi

Mumbai.

Article Received on 18 July 2016,

Revised on 07 August 2016, Accepted on 27 August 2016

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INTRODUCTION

The change in arterial blood pressure and pulse- rate is one of the generally known

physiological changes in aging of man. Many factors are responsible for the rise of blood

pressure of which age is one of the factors. Pooling of blood in lower extremities occur due to

gravitational effects. It reduces venous return and stroke volume with a fall in systolic blood

pressure.

Short Term regulatory mechanism (Baroreceptor reflex) is operated to maintain normal blood

pressure. This hemodynamic homeostasis becomes less effective with aging and is associated

with a decreased ability to regulate blood pressure.

Blood pressure is a measure of cardiovascular reactivity reflecting autonomic function. Also

such elder ones having some associated diseases like hypertension, diabetes mellitus, and low

blood volume become further weaker. The primary purpose of this study is to observe the

postural variation of blood pressure and to compare.

MATERIAL

Selection of Groups: The subjects selected for this study are 50 in number with age group 15 to >55 years of both sex and they are categorized into four groups based on their age.

Inclusion criteria: The study includes healthy subjects, subjects of mixed socioeconomic status.

Exclusion criteria: Subjects with diabetes mellitus, hypertension, any other debillating illness, cardio-respiratory diseases and other diseases, Subjects with obesity were excluded,

Subjects with smoking and alcoholism, Subjects who are on medication were excluded, who

unable to stand were excluded.

Study Protocol: When assessing blood pressure it is important to take the position of the patient into consideration. For one minute, the blood pressure was subsequently taken lying

position. After at least one minute of standing, the blood pressure was then taken standing,

with the arm supported at the elbow and the cuff at the heart level. Finally, after one minute

the blood pressure was again taken in this last position to find out the error difference. The

blood pressure tended to drop in the standing position compared with the lying. Error

difference in blood pressure was found in standing position by double recording.

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Measurement of blood pressure: Blood pressure was measured with a standardized sphymanometer, adjusted to zero. Blood pressure was recorded as per guidelines given by

World Health Organization/International Society of Hypertension (WHO/ISH) - the patient

may also be supine or standing provided that the arm is supported at heart level for all body

postures.[2]

STATISTICAL ANALYSIS: Statistical analysis was done by t-test.

RESULTS Table I

Age groups in Years Males Females Total

15 – 25 15 13 28

26 – 35 3 5 8

36 – 45 1 1 2

46 – 55 5 7 12

Total 24 26 50

From Table I, it was found that study was done on 40 normotensive persons, on the basis of

their age.

Table II

Blood Pressure recorded in

Lying down Standing I Standing II

125/74 97/75 108/99

118/74 115/78 120/79

105/69 101/66 99/63

101/54 110/56 104/69

122/75 140/121 138/107

117/79 99/52 126/59

120/66 124/95 128/67

122/64 140/80 121/69

116/90 101/89 106/79

121/73 135/79 121/82

120/71 153/81 135/79

118/65 110/68 117/74

121/66 132/76 135/72

119/68 121/77 106/80

114/73 110/73 130/110

117/79 106/94 120/70

117/71 109/68 107/85

123/62 132/81 133/72

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From Table II, it is found that blood pressure varies in lying position than in standing position

(p<0.01) with less error in blood pressure recording (p<0.05)

Table II also shows that both systolic blood pressure and diastolic blood pressure increases in

standing position.

After doing statistical analysis, thus it was found that there is significant correlation in

between blood pressure varies in lying position than in standing position (p<0.01) with less

error in blood pressure recording (p<0.05)

DISCUSSION

Many factors influence an individual's blood pressure measurement. However, guidelines for

accurately measuring blood pressure inconsistently specifies that patient's position and they

should keep feet flat on the floor.[2]

Healthy elderly subjects aged above 60 years had a higher baseline systolic and diastolic

blood pressure when compared to the younger age group. As age increases, large arteries

gradually stiffen and small arteries may become partially blocked and this tends to increase

the blood pressure. This could be the reason for the higher baseline blood pressure in the

subjects aged 60 years and above.

At first min of standing, systolic blood pressure is decreased and diastolic blood pressure is

increased in all the four groups. When an individual stands up from a sitting posture earth’s

gravitational forces start acting in the long axis of body trying to minimize the venous return.

This results in fall of cardiac output and stroke volume.

Blood pressure triggers the sino-aortic mechanism. Vasomotor Centre (VMC) becomes active

and so sympathetic discharge increases. This mainly increases peripheral resistance and heart

rate. But as age increase this sensitivity of Baroreceptor decrease. Baroreflex control over

chronotropicity (as well as inotropicity) is a means to the end of controlling arterial pressure

via changes in cardiac output. So in the elderly the systolic blood pressure decrease is more.

Thus major mechanism utilized by the arterial baroreflex is to control arterial pressure in

various conditions, is modulation of peripheral vasoconstriction.[3]

Hemodynamic status is modulated by the nervous system, by integrating signals originating

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and arterial chemoreflex). In healthy individuals, the final result is that sympathetic activity

to cardiovascular apparatus augments and prevails over parasympathetic tone, which

conversely declines.[3]

Due to decreased elasticity of walls of blood vessels the diastolic blood pressure remains at

high level compared to younger group. After 3 minutes of standing the diastolic blood

pressure is brought back to normal or remains high. Systolic blood pressure remains low, as

venous return remains low. Some rigorous test shows increased systolic pressure variability

in the elderly.

ACKNOWLEDGEMENTS: I am grateful to my mother Anjali, husband Rajendra, daughter Vaishnavi and all subjects who are involved in this study for their prestigious help in this

study.

BIBLIOGRAPHY

1. Hanna Tolonen Challenges in standardization of blood pressure measurement at the

population level; BMC Med Res Methodol. 2015; 15: 33.

2. Ismet Eser Theeffect of different body positions on blood pressure; Journal of Clinical

Nursing 16(1): 137-40 · January 2007.

3. Antonio C. L. Nobrega, Neural Regulation of Cardiovascular Response to Exercise: Role

of Central Command and Peripheral Afferents; BioMed Research International;

Volume 2014 (2014).

4. Aina Emaus Blood pressure, cardiorespiratory fitness and body mass:Results from the

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