luni, 11 martie 2013

Blood Pressure in Calves



The European College of Veterinary Internal Medicine – Companion Animals.
17 th ECVIM-CA Congress & 9 th ESVCP Congress.
13 th – 15 th September 2007 – Budapest – Hungary.



Indirect oscillometric  blood pressure
in conscious  calves

Brăslaşu M.D., Brăslaşu Daniela Elena, Brădăţan Cătălina,
Balint Emilia F..  Tirifon Eugenia

Faculty of Veterinary Medicine Bucharest, Romania



Arterial  blood  pressure measurements were obtained from 150 healthy calves using the oscillometric technique to establish reference values for the specie.
Calves with ages between 2-13 years old (5,77±5,61 years) were examined in standing position.  Arterial  blood  pressure was measured from coccygeal vertebra. Systolic arterial pressure value was 103,75 ± 1,68 mmHg. Diastolic arterial pressure was 56,48 ± 1,29 mmHg. Mean arterial  pressure was 72,26 ± 1,37 mmHg.
There were observed increases of arterial blood  pressure in following situations: food administration, defecation and urination, and also in decubital state.

MATERIAL AND METHOD

150 head of bovines from Holstein and Brown breeds, 1 to 10 years old, were examined while awake and in standing position.
The oscillometric method – OMRON R1 device-  was used in order to establish the blood pressure.
The sleeve of the device was fixed at the tail’s base with the sensor situated ventrally on the coccygeal artery.
5-10 determinations were realized for each animal (systolic, diastolic and pulse) and the arithmetic mean was calculated.
The mean arterial pressure was calculated based on the following formula:
            MBP = DBP + (SBP – DBP)/3.
MBP –mean arterial pressure
DBP –diastolic arterial pressure
SBP –systolic arterial pressure
Statistic interpretation was relied on the following parameters:
-  arithmetic average  x = ∑ x/n
- standard deviation s = √s2
  - variance s2 =     n∑x2 – (∑x)2
                                        n ( n-1)
- error of the mean x = s/√n
- the coefficient of variability V% = s/x  ∙ 100.



Results and debates


The aim of the experiments was to establish:
A. the values of systolic, diastolic and medium arterial pressure     in clinical healthy cows
B.   physiological variations of arterial pressure depending on: animal position, different physiological states
C.   variations of arterial pressure depending on age;
D.  pathological changes of arterial pressure – arterial hypertension.



A.   Values of arterial pressure in bovine

The values of arterial pressure (oscillometric method) are presented in Table 1.

Table 1
The values of arterial pressure in bovine
- oscillometric method-


Statistical values
Systolic pressure
(mmHg)
Diastolic pressure
mm Hg
Mean arterial pressure
mm Hg
n =
150
150
150
Mean
103.75
56.48
72.26
Standard deviation
20.61
15.88
16.77
Variance
424.93
252.39
281.44
Mean error
1.68
1.29
1.37
Var. values
19.86
28.11
23.20


It can be inferred from the table above:
-         systolic pressure = 103.75± 1.68 mm Hg
-         diastolic pressure  = 56.48 ± 1.29 mm Hg
-         mean arterial pressure = 72.26 ± 1.37 mm Hg
-         the variability index is medium in case of systolic pressure and increased in the case of the two others values
-         it has been considered that the variance and standard deviation have increased values because of the reduced number of animals used to determine the arterial pressure and first of all, because of the multiple physiological factors that influence the arterial pressure

A. Physiological variations of arterial pressure

Increased values of arterial pressure were observed when the determinations were realized on recumbent position animals (Table 2)
Table 2
Modification of arterial pressure depending on animal position


Nr. crt.
Arterial pressure
- standing position -
Arterial pressure
- decubit -
Systolic pressure/Dyastolic pressure
mm Hg
Systolic pressure/Dyastolic pressure

mm Hg
1.
161.33/68
160/96
2.
99.4/60.3
132.7/84.7
3.
93.33/53.83
148.28/108
4.
95.2/49.4
155.33/98
5.
98.8/40
150/68
6.
70.85/35.42
120.14/74.42

It has been considered that the increasing values of systolic pressure are due to the pressure of the rumen on the thoracic cavity, implicitly on the heart and large vessels.
The increase of arterial pressure was also determined by:
-         the pulses caused by the noise of tractors bringing the food;
-         defecation (ex. increase from 66/32,2 mm Hg to 69/36 mm Hg)
-         urination (ex. from 66/32.2 mm Hg to 87/51 mm Hg).
The decrease of arterial pressure has been observed after parturition (ex: from 90.57/43.42 to 74.62/41.37, in the first day after parturition)

A.   Variations of arterial pressure depending on age
If in human beings there is an increase of arterial pressure simultaneously with the age, followed by a decrease, in bovine, there are no significant variations depending on the age of the animals– Figures 1-3.
.
Figure 1



Figure 2

Figure 3



A.   Pathological changes of arterial pressure – arterial hypertension

From the 150 examined cows, 6 animals presented arterial hypertension (we could not establish the causes of the hypertension). The values are presented in Table 3.

Table 3
Arterial hypertension in cows


No.
Systolic pressure
mm Hg
Diastolic pressure
mm Hg
Mean arterial pressure
mm Hg
Age
(years)
1.
143.37
83
78,73
8
2.
161.33
68
88,93
8
3.
153.66
77,66
95,26
4
4.
186.6
110,2
52,33
5
5.
146.6
103,3
60,06
6
6.
177
116
61
6


The last 3 cows have had increased values of systolic and diastolic arterial pressure, but mean arterial tension was in „physiological limits”.



Conclusions


1.                                    In bovine, the arterial pressure can be determined using the oscillometric method, the animals undergoing this method very well. The cows were examined while awake and in standing position.
2.                                    The values (mm Hg) were: systolic arterial pressure=103.75 ± 1.68; diastolic arterial pressure=56.48 ± 1.29 and mean arterial pressure= 72.26 ± 1.37.
3.                                    No significant variations related to animal age have been detected.
4.                                    In case of determinations realized on recumbent position animals there was an increase of arterial pressure, also noticed during defecation, urination and stimuli which anteceded food administration. The decrease of arterial pressure has been observed in the first day post-partum.
5.                                    6 cases of arterial hypertension have been observed.















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