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| | == Methods of Blood Pressure Measurement == | | == Methods of Blood Pressure Measurement == |
| − | Arterial blood pressure can be measured either '''directly''' or '''indirectly'''. | + | Arterial blood pressure can be measured either |'''directly''' or [[Blood_Pressure_Measurement#Non_Invasive_Methods|'''indirectly''']]. |
| − | **horses: base of the tail.
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| − | It tends to be difficult to obtain an accurate blood pressure reading in the conscious animal due to the effects of the situation. Some cats, for example, may suffer from the "white coat effect". That is their stress levels have already increased due to being in an unusual environment, and when the vet attempts to take the blood pressure, this will stress them out even more. This has the effect of increasing the blood pressure. That said however, there are still ranges of normal blood pressure that take this into account. It is also difficult to obtain an accurate reading in a sedated or anaesthetised animal because most drugs have an effect on blood pressure. However, measurements can still be taken during surgery, for example, to compare throughout the procedure.
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| − | === Indirect Methods ===
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| − | The width of the cuff that is used in indirect methods of blood pressure measurement is also important in getting accurate readings, in relation to the cross-sectional area of the limb or tail. The width of the cuff should be 40% of the circumference of the area the cuff is being placed. The cuff should be applied so that only a small finger can be inserted between the cuff and the leg, to ensure that it is neither too tight nor too loose.
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| − | 1) '''Doppler Ultrasound''':
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| − | An inflatable cuff is attached to a manometer. As the cuff is inflated, it occludes the artery, and a piezoelectric crystal placed over the artery distal to the cuff detects blood flow. The cuff is slowly released until blood flow returns to the artery - this causes a frequency change in sound waves, and is detected by the piezoelectric crystal, which converts it into sound detected by the operator. As the sound is detected, the cuff pressure is equal to systolic pressure.
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| − | 2) '''Oscillometric Techniques''':
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| − | An inflatable cuff is used to occlude the artery, and it detects the oscillations of blood flow while the artery is partially occluded. Systolic pressure, mean pressure and diastolic pressure can all be calculated. The cuff is attached to a control unit which continually detects arterial pressure. The cuff inflates until the artery is occluded, and then automatically begins to deflate. The first oscillation of blood flow detected is the systolic pressure, the largest oscillation is equal to the mean pressure, and the oscillations subside at diastolic pressure.
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| | [[Category:Vascular System - Anatomy & Physiology]] | | [[Category:Vascular System - Anatomy & Physiology]] |
| | [[Category:To Do - AP Review]] | | [[Category:To Do - AP Review]] |
| | [[Category:Blood Pressure]] | | [[Category:Blood Pressure]] |