Anaemia

• Hb level below that for normal limits which are:

            - Male 13-17 (g/dl)

            - Female 11-16 (g/dl)

• Acute/chronic blood loss (hypochromic)

• Lack of vitamin B12 or folate (megaloblastic)

• Marrow failure (hypoplastic)

• Increased haemolysis

• Red blood cell abnormalities (spherocytosis/sickle cell/G-6-PD deficiency)

• Mechanical trauma: burns or prosthetic heart valves

• Sepsis, antibodies, uraemia, hypersplenism 

• CaO₂=1.34 x Hb x Sat + 0.03[PaO₂] units ml/dl

• Maintenance of O₂ delivery depends upon increasing cardiac output

• Hb is an important buffer for CO₂- thus, acidosis is more likely

• Right shift of oxy-Hb curve

• Transfused blood has low levels of 2,3-DPG, and  therefore unloads O₂ poorly

Management

• Optimised O₂ carriage pre-op (Hct >0.3, Hb >10 g/L)

• Maintain O₂ saturation

• CVP and urine output monitoring and also arterial line

• Consider pulmonary artery catheter to maintain high CI

• Select a technique to preserve CO and O2 delivery. This may need a high FiO₂. Avoid hyperventilation

• Post-op: transfuse to 12 g/dl. Continued O₂ therapy until stable

• Consider ITU/HDU.