Fluids Flashcards
Discuss calculating maintenance requirements
Maintenance requirements
- replace insensible loss
- replace ongoing abdnormal loss
- attend to specific o2 carrying, coagulation, electrolyte or acid-base and nutritional requirements
Average
Water: 30ml/kg/day
sodium: 2mmol/kg/day
Potassium:1mmol/kg/day
Discuss insensible losses
Faeces 100ml/day
lungs 400ml/day
skin 600ml/day
Discuss common sites of abnormal fluid loss in ICU
Stoma, drains, fistula
Vomiting and diarrhoea
polyuria
gastric aspirates
Discuss use of cyrstalloids
Essentially sterile water with the addition of electrolyes
may be hypo, iso or hypertonic
Advantages
- Cheap
- nil need for cross matching
- no anaphylaxis
- resus ECF
- promotes urine output
Disadvantages
- only 25% remains in circulation rest enters the interstium
- risk of peripheral and pulmonary oedema
- requires large resus volumes up to 3 x
Discuss use of coloid
examples include albumin, 6% hetastarch and 10% pentastarch
Advantage:
- 50-100% remain intravascular
- spares pulmonary and interstitial space
Disadvantage
- expensive
- does not retore interstitial volume
- enters interstitial space if leaky
- immune reaction and problem with cross matching
- long tissue half life
Discuss FFP
Usually for non-specific coagulation disturbances
FFP has an INR of 1.6 and cannot lower the INR lower then 1.7
Contains vitamin K dependent factors in a ratio of 1unit per ml
FFP contains all coagulation factors in normal concentrations.
Discuss prothrombinex
The 3 factor prothrombin complex contrate
provision of factors II, IX and X
Discuss the use of platelets
Both thrombocytopenia and platelet function disorders are an indication for platelet transfusion
Aim to keep above 100 if active bleeding
IN sepsis threshold for transfusion is <5 in all patient and <30 in patient with additional risk of bleeding
Discuss TRALI
Defined as hypoxia and bilateral pulmonary oedema in the absence of other causes such as cardiac failure
Pathophys:
2 hit” model: lung capillaries are primed by an underlying illness then triggered by exposure to irritant in blood transfusion
— Step 1: underlying illness -> complement activation -> pulmonary sequestration of neutrophils
— Step 2: transfusion -> neutrophil activation -> endothelial cell damage and capillary leak syndrome
Diagnosis
- acute onset ALI(within 6 hours of a transfusion
- hypoxia (PaO2/FiO2 <= 300mmHg regardless of PEEP or SpO2)
- bilateral pulmonary infiltrates
- not cardiogenic in origin (PAWP < 18mmHg)