Adult estimated blood volume (EBV) is calculated by actual weight (kg) as follows:
Nonobese adults have 70 ml of blood volume per kilogram of body weight.
EBV = 70ml x weight (kg)
Things are a little different if your dealing with the obese patient. Circulatory volume is actually augmented in the obese, but not in the same proportions as the nonobese patient. This is because fat only contains 8% – 10% water, whereas muscle contains much more. So, for the obese, we use 45 – 50 ml/kg. For numbers sake, lets keep it easy and say 50 ml/kg.
Obese EBV = 50ml x weight (kg)
Pediatric patients, as you might guess, are different. The table below shows the volumes per kilogram of body weight you should use.
Age Group | Volume (ml/kg) |
---|---|
Premature | 90-100 |
Newborn (< 1 month) | 80-90 |
Infants 3months to 3 years old | 75-80 |
Want to make it really easy? Use our online calculator by clicking here
References
Nagelhout. Nurse anesthesia. 5th edition. 2014.