Fluids Flashcards
Ideal body weight equation?
Male = 0.9H - 88 Female = 0.9H - 92
Distribution of body fluid?
2/3 - intracellular
1/3 - extracellular - of that 2/3 - interstitial, 1/3 intravascular
What is osmolality?
Osmoles per kg of solvent (water)
What is osmolarity?
osmoles per L of solution
What is Tonicity?
The ability of a solution to cause water movement
Risk of giving too much hypotonic sln?
Haemolysis
2 types of fluids?
Crystalloids (when dissolved forms true solution and can pass through a semipermeable membrane)
Colloids (mixture of microscopically dispersed particles in another medium)
Positive of Hartmanns?
Salt levels resemble human plasma
Risk of rescus with saline?
Alkalosis, hypercholaemia and hypernatraemia
Risk of rescus with glucose?
Like giving ‘free’ water and make pt hyponatraemic
What are sensible losses?
What you can see eg blood, urine, vomit
What are insensible losses?
What you cannot see - sweating, humidifying air you breathe
Loss into third space - fluid not left body but in unuseable space e.g. in pancreatitis - (can get hypovolaemic shock from ascites)
What can urea and creatinine show about kidney impairment?
Urea - acute
Creatinine - chronic
Correcting fluid deficit?
Correct over 12-24hrs 100ml per kg for 1st 10kg 50ml per kg for 2nd 10kg 20mg per kg thereafter 4/2/1 per hour Asses result and watch for other values - eg Hb may initially seem normal but as you rescusitate, haemodiluted and Hb falls Assess urine output - want 0.5mL/kg/hour
What are some signs of dehydration?
irritability, restlessness, lethargy, unconsciousness, sunken eyes, dry mouth
