- There may be a significant difference between the prescribed ‘dose’ and that which is actually delivered – estimated using clearance equations to be 73% in practice
- Due to a number of factors:
- Treatment downtime due to filter clotting
- Technical problems such as boor blood flow and recirculation
- Reduced filter efficacy over time
- Effects of pre-dilution
- It is recommended that a dose of at least 35 ml/kg/h (post-dilution) is prescribed for CRRT
- This ensures that an adequate dose of CRRT is delivered despite downtimes and other limiting factors
- Increasing the dose may cause loss of essential molecules and thus affect outcome:
- Antibiotics – many significantly cleared by RRT
- Amino acids and proteins
- Micronutrients (vitamins, selenium, folic acid)