Fluids

Fluids

A general goal for all fluid administration is the restoration of intravascular volume. However, a second goal may be to ensure good oxygenation of the blood with an appropriate level of haemoglobin. Up to a decrease in haemoglobin of 5 mmol/l, crystalloid fluids are preferred. Beyond this, packed cells or other blood products can be administered.

Fluids are subdivided into crystalloid (similar osmolality to intravascular volume) and colloid (expand intravascular volume) solutions. The most commonly used crystalloids for hypovolaemic shock are normal saline or lactated Ringer's solution.

Colloid solutions include 5% albumin and Voluven (heta-starch). The benefits of one type of fluid replacement therapy versus another have not been established. Due to the expansive nature of colloid solutions, smaller volumes of these agents are required.

1

Consider the following two statements:
I. An advantage of colloids is their slow passage over the capillary wall due to their large molecular weight.
II. A disadvantage of cristalloids is their short duration of extracellular volume supply because of their quick passage to the interstitium.

2

A patient is transferred to the emergency unit after a severe accident. He suffers from extensive bleedings and his hematocrit has dropped below 30%. Which infusion is appropriate at this stage?

3

A patient with severe hypovolaemic shock after myocardial infarction is transferred to the emergency unit. Her Hb is normal. Which infusion is appropriate at this stage?