Transfusion medicine handbook

8. Clinical Alternatives and Applications

8.2 Non-blood Plasma Volume Expanders

The judicious use of plasma volume expanders can result in adequate restoration of blood volume.

However, positive fluid balance is an independent predictor of poor outcome in ICU patients. There is increasing adoption of permissive hypotension (hypotensive resuscitation), leading to more restrictive intravenous fluid administration in the critically ill than previously.

Crystalloid Solutions

Initial resuscitation, in adults, should be with 1 - 3 litres of a crystalloid solution such as Plasmalyte 148, pH 7.4 (an isotonic non-calcium containing 'balanced' solution buffered with acetate) or 0.9% sodium chloride ('normal' saline). Adequate crystalloid resuscitation may often avert the need for other plasma expanders. Colloid products can then be used in the recommended doses. If prolonged volume expansion is required, such as in a severely ill trauma patient, then the use of albumin solutions rather than synthetic colloids is likely to be justified.

Plasmalyte 148 in 5% Glucose, dextrose solutions and compound sodium lactate (CSL) solutions, e.g., Hartmann's or Ringer-Lactate, must not be administered simultaneously with a red cell infusion as the solutions are not compatible. No drugs or additives, other than 0.9% sodium chloride intravenous infusion, are recommended to be mixed with red cells before or during transfusion.

Synthetic Colloid Solutions

Colloids should only be used if crystalloids are insufficient to stabilise a patient. Due to the risk for acute renal damage and a requirement for dialysis, the use of synthetic colloids, particularly starch solutions, should be avoided in critically ill patients and those with sepsis or pre-existing renal dysfunction. In these situations, and where colloids are required, the use of albumin solutions is likely to be justified.

Hydroxyethyl Starch (Voluven 6%; Volulyte 6%)

Hydroxyethyl starch (HES) solutions provide an alternative colloidal fluid to albumin and plasma for use in plasma volume expansion. HES solutions should be avoided in patients with sepsis or in critically ill patients because of the risks of kidney injury and mortality [1].

Voluven 6% and Volulyte 6% are solutions of HES in 0.9% sodium chloride. Infusion results in a plasma volume increase of approximately 100% of the infused volume and the effect lasts four to six hours. These should be restricted to the initial phase of volume resuscitation with a maximum duration of use of 24 hours [2] [3] .

Anaphylactic/ anaphylactoid reactions (hypersensitivity, mild influenza-like symptoms, bradycardia, tachycardia, bronchospasm, non-cardiac pulmonary oedema) are rare (≥1/10,000 to <1/1,000) and patients should be closely monitored at least while the first 10 - 20 mL are infused. Disturbances of blood coagulation, beyond dilutional effects, can occur [2] [3].

Oxygen Carrying Compounds

Although red cell substitutes in the form of haemoglobin-based oxygen carriers, including polymerised haemoglobin and haemoglobin conjugated with polyethylene glycol, and perfluorocarbon oxygen carriers have been under investigation for many years, there is no indication that these compounds will be widely available for routine use in the near future.