Non-invasive measurement of systemic arterial pressure in guinea pigs by an automatic oscillometric device

BACKGROUND: There is no useful oscillometric device to measure the systemic arterial pressure in small experimental animals except rats. Therefore we evaluated a recently developed automatic oscillometric device for the indirect blood pressure measurement in guinea pigs.METHODS: Twenty male Hartley guinea pigs were used. We found that unanaesthetized guinea pigs stayed comfortably in a guinea pig-holder without training. A pneumatic cuff was placed snugly around the crus of the left limb. Cuff size was selected according to previous recommendations (cuff width = limb circumference x 0.4). Systolic blood pressure corresponded to the point at which oscillations began to increase; mean arterial pressure corresponded to the point at which the oscillations peaked. Diastolic blood pressure was calculated from the values of systolic and mean blood pressures. To test the accuracy of this device, the direct and indirect values were arbitrarily collected from simultaneous recordings of six anaesthetized guinea pigs with various levels of blood pressure induced by intravenous noradrenaline infusions. RESULTS: The oscillometric device for indirect blood pressure measurements allows the measurement of blood pressure easily and quickly. Twenty unanaesthetized guinea pigs had a heart rate of 280.0 +/- 6.7 beats/min (mean +/- SEM) and systolic, mean and diastolic blood pressures of 94.0 +/- 2.2, 63.6 +/- 1.7 and 48.4 +/- 1.6 mmHg, respectively. These values are almost the same as those found in earlier studies. Correlation coefficients between direct and indirect values were > 0.9 for all blood pressures. CONCLUSIONS: These results suggest that this device may be valuable for monitoring systemic arterial blood pressure in guinea pigs.