Fluid Management in Surgical Patients
Maintenance
Composition
NOTE: All bags are 1L each. Add up to correct composition (3/4/5L and Na+K)
NOTE: 1st 24h post op, just give 3L Hartmann's (15mmol K+) as cell breakdown increases serum K. Revert to formula after 1/7 post op.
NOTE: Max rate for K = 10mmol/h
Existing fluid deficit
Assess clinical state, NOT fluid balance chart:
Ongoing loss
Fluid resus (Emergency resus)
Source
Dr Fiona Lee 2014
- Weight dependent
- 50kg --> 2L
- 70kg --> 3L
- 90+kg --> 4L
- Give lesser (less 1L) if: CRF, CCF, Age >80y
Composition
- Na --> 2mmol/kg BW ~140mmol
- K --> 1mmol/kg BW ~ 70mmol
- Hartmann's 129mmol Na/ 5 mmol K (composition of ECF)
- N Saline: Na --> 150mmol, K - 0
- 5% dextrose: Na --> 0, K --> 0 (may cause interstitial oedema)
- 4% dextrose 1/5 N saline: Na --> 30mmol
- Red lettering bag: + 30mmol K (for N saline and dextrose bags, none for Hartmann's)
- Mini bag: 100mmol Na + 10 mmol K
- Laparotomy: Aim for serum K >4. <4 --> add 30mmol K, <3.5 add 60mmol K, <3 add 90mmol K (Add red bag)
NOTE: All bags are 1L each. Add up to correct composition (3/4/5L and Na+K)
NOTE: 1st 24h post op, just give 3L Hartmann's (15mmol K+) as cell breakdown increases serum K. Revert to formula after 1/7 post op.
NOTE: Max rate for K = 10mmol/h
Existing fluid deficit
Assess clinical state, NOT fluid balance chart:
- 2 hard (urine output - 0.5ml/kg/h, JVP - N visible sitting @ 45o) / 2 soft (skin turgor-sternum!, cap refill/ mucous membranes)/ 2 vital (BP + HR)
- +1L for mod dehydrated, +2L moderately,, +3L for severely
- Type of fluid: Dehydrated: N saline/ Hartmann's, Blood loss: transfusion, Burns: Colloid
Ongoing loss
- HOW?: Drain, Ileostomy (stoma - Up to 2L loss), N+V, Diarrhoea, 3rd space loss (Ileus), abnormal urine output (post ileus diuresis D4 post op - don't chase fluids, post obstructive diuresis - chase, neurosx (diabetes insipdus- chase)
- Day 1-3, ileus +1L
- Type of fluid: Hartmann's. If K dec, use N saline
Fluid resus (Emergency resus)
- 1L stat + 1L @ 1L/h. Use NS or Hartmann's.
- If K low, use NS + 30mmol KCL @ 1L/4h
Source
Dr Fiona Lee 2014