Fluid and electrolyte management

Question 1

importance of adequate nutrition in surgery?

Answer 1

wound healing
faster recovery
reduce incidence of infections
reduce loss of muscle mass

Question 2

why is loss of H20 increased in an ileostomy e.g. in Crohn’s disease?

Answer 2

loss of colonic reabsorption of H20

Question 3

best guide to success of resuscitation?

Answer 3

resumption of normal urine output, so should measure hrly urine output
CVP measurement will help in adjustment of rate of infusion

Question 4

indications on ptnt examination for resuscitation?

Answer 4

thirst
dry mucous membranes
loss of skin turgor
sunken eyes
tachycardia/fast pulse rate
hypotension
poor peripheral perfusion- slow capillary refill time
low JVP
oliguria/anuria

Question 5

what should urine output at least be?

Answer 5

0.5ml/kg/hr

so 70kg male= 0.5X70= 35ml/hr, or 840ml/24hr, around 1L normal.
>3L polyuria
<50ml anuria

Question 6

why might urine output be low post-op?

Answer 6

pre-renal- dehydration?
renal- CKD?
post-renal- blocked catheter?

Question 7

crystalloid fluids examples?

Answer 7

normal saline (0.9%)
dextrose (5%)
combinations
hartmann’s- most physiological, electrolyte composition of closest resemblance to plasma

Question 8

colloid fluids examples?

Answer 8

albumin
gelofusine/volpex
starch
blood products

last longer intravascularly

Question 9

max. safe rate of delivery of K+ on the ward?

Answer 9

5mmol/hr

Question 10

fluid maintenance requirements?

Answer 10

Na+= 2mmol/kg/24hr
K+= 1mmol/kg/24hr
H20= 40ml/kg/24hr

so 70kg male:
140 Na+
70 K+
2.8 L water

e.g. 1 L 0.9% normal saline with 20 K+, 2X dextrose 5% with 20 K+ each.

Question 11

in fluid resuscitation, how is fluid given?

Answer 11

IV boluses and titrated to response

must be frequent reassessment every 15 mins

Question 12

examples of ptnts with abnormally high fluid losses?

Answer 12

vomiting
diarrhoea
high output stoma
enterocutaneous fistula

Question 13

ions lost in diarrhoea?

Answer 13

K+

HCO3-

Question 14

ions lost in vomiting?

Answer 14

K+
H+
Cl-

Question 15

risks of given IV fluids in ptnt having suffered trauma (so bleeding) with hypovolaemic shock?

Answer 15

volume overload
increased risk of bleeding- IV fluids will increase BP, so increase flow through area of bleeding which may increase risk of clot, consuming clotting factors and increasing bleeding risk.