Decreased Spontaneous Baroreflex Sensitivity as an Early Marker for Progression of Haemorrhage
Kavita Yadav1, Akanksha Singh1, Smriti Badhwar1
1Department of Physiology, All India Institute of Medical Sciences, Room No. 2009, Teaching Block, Second Floor, Ansari Nagar, New Delhi, India.
Introduction:
Blood donation provides an ideal setup for assessment of cardiovascular responses to mild hypovolemia for understanding the underlying mechanisms.
Aim:
To evaluate cardiovascular responses in time and magnitude by estimating the spontaneous baroreflex sensitivity (BRS) during and after donation of 450 ml of blood.
Methods:
Continuous beat-to-beat blood pressure and lead II ECG was recorded before, during and after blood donation in 54 healthy volunteers (age 34.7 ± 5.08 years; weight 77.9 ± 8.20 kg), followed by offline analyses of baroreflex sensitivity.
Results:
The systolic, diastolic or mean blood pressures did not change during or after the blood donation. Decrease in pulse pressure and increase in heart rate was observed post donation. The spontaneous BRS decreased during [8.68 (6.038-12.69) ms/mmHg] and after blood donation [9.401 (6.396-11.59) ms/mmHg] as compared to the baseline [12.83 (6.884-18.18) ms/mmHg] with a significant decrease in α-HF on spectral analysis.
Conclusion:
Mild blood loss (450 ml) results in non-hypotensive haemorrhage with a decrease in spontaneous BRS before the rise of heart rate during blood donation.
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