Surgery - Fluid prescribing

Question 1

Fluid prescribing

Answer 1

The 5 Rs Resuscitation
↓
Routine maintenance
↓—————————–↓————————–↓
Redistribution Replacement
Adjust maintenance Add to maintenance
↓—————————↓——————————↓
Reassess

Question 2

Resuscitation

Answer 2

• Shocked pt, normal CVS with no pulmonary oedema
• 500ml Hartmanns or 0.9% saline over 10-15 minutes
• Reassess using ABCDE
• Give further challenges up to 2000 ml
• Leg raising
• All depends on what major fluid loss is

Question 3

Routine maintenance-1

Answer 3

• In normal patients ( see NICE )
• Water 25-30ml/kg/24hrs
• Na, K ( Cl follows Na ) all 1 mmol/24 hr
• Glucose 50-100gm/24 hours ( 5% dextrose contains 50gm/litre )
• Obese-adjust according to their ideal body wt. Few need >3000ml/24hrs
• Elderly, frail, renal/cardiac impairment, give 20-25ml/kg/24hrs
• Consider giving routine maintenance during daylight hrs

Question 4

Routine maintenance-2

Answer 4

• Day 1
• 25-30ml/kg/24 hrs 0.18% saline and 4%dextrose c 20mmol KCl
• OR a mixture 0.9% saline and 5% dextrose,in a ratio ONE bag saline and TWO bags dextrose with added KCl
• The potassium would increase on day 2
• This is to start with and needs review and checking of the pts condition, urine output, at least daily U&E’s
• Summon help if not going to plan

Question 5

Replacement and redistribution-1

Answer 5

• Adjust fluids/electrolytes to
• Account for existing fluid electrolyte excess/deficit
• Ongoing losses
• Abnormal (3rd space losses )
• Oedema
• Severe sepsis
• Cardiac, liver or renal impairment
• Abnormalities of fluid retention/distribution/↑↓Na, K, acid/base

Question 6

Replacement and redistribution-2

Answer 6

• Severe sepsis poses major threat
• HDU care, invasive monitoring and large volumes of well chosen fluid plus everything else needed to keep major organs working
• Don’t forget simple thing like thirst
• The following diagram ( NICE ) shows ongoing fluid/electrolyte loss which must be accounted for

Question 7

Reassessment

Answer 7

• Old fashioned methods not used ( Rectal, subcutaneous )
• Sepsis at site of cannula ( regular change ) local/distant comps (sbe)
• Blood and 5% dextrose do not mix ( red cells aggregate )
• Patient comfort
• Adverse events-under transfusion, fluid overload ( not common ), electrolyte imbalance, air embolus
• Some fluids, (NaHCO3 ) drugs CaCl2 are VERY corrosive
• Do not prescribe for >24 hrs,
• Assess fluid status at least daily, and check U&E’s

Question 8

NICE fluid chart

Answer 8

Question 9

Example-1

Answer 9

• 75 kilo man 1 day post op
• Fluid balance/ urine output satis and on sips ( 500ml/24 hrs )
• If there is deficit or excess include that in iv rota
• How much/what fluid does he need /24 hrs
• Add losses
• Urine
• Insensible
• Others ( n/g tube, drain )
• Add input
• Oral
• IV

Question 10

Example -1 Answer

Answer 10

• Daily requirement 30 ml/ kg so 2250ml
• Urine output 1300 ml (say ),Insensible loss 800 ml, N/G aspirate 200 ml
• So losses are 2300 ml
• He is taking 500 ml/hr
• The ivi should give 1800ml/24 hrs
• Daily requirement Na and K
• 1 mmol each ( check electrolyte content of n/g bag )
• So ivi could be 1000 ml Nsaline,+ 1000 ml 5% dextrose over 12 hrs each plus 80 mm Kcl ( care c KCL )

Question 11

Example-2

• 75 yr old man receives fluids after a CVA for 3 days and is on sips
• The ivi gives 3000ml/24 hrs, oral fluid is 500 ml/24 hrs and urine output is 1500 ml/24 hrs
• He has peripheral oedema and a raised JVP
• Input 3500 ml
• Losses 1500 +800 =2300
• Net gain is 1200 ml/24hrs
• What do you do
• Stop fluids +/- frusemide
• Not a huge excess so he may have had some CCF previously

Answer 11

Example 3

80 year old man had THR this morning

Asked to see because urine output has fallen for 3 hrs
Nurses think you should do something. What?
O/E the pt is warm and well perfused (euvolaemic )
Catheter, abdo ,observations etc all ok and 3 litres +ive since op
Hb 10.5 gm/dl U& E all satis. Lactate 1.8mmol/L
You say all ok

Question 12

Osmolality and Osmolarity

Answer 12

• A mole is the gram molecular weight of a substance
• An osmole refers to the no. moles of solute that contribute to the osmotic pressure of a solution
• OsmoLality-a measure of the osmoles/kiLo of solvent ( lab )
• OsmolaRity- the number of osmoles of solute/litRe of solution
• Normal value 280-295 mOsm/kg
• *Where the amount of solute is small compared to the volume of solvent, the values are close*
• Normal value-slightly less than the above ( plasma including solutes )

Question 13

Osmotic Pressure

Answer 13

• Osmotic pressure exerted by non-diffusible particles in a soln. is determined by the NUMBER of particles-NOT mass
• One osmole-the number of molecules in 1 gm. mol. wt. of undissociated solute
• One molecule of Albumin mol. wt.70,000 has the same osmotic effect as
• One molecule of glucose mol.wt 180
• NOTE, one gram molecular wt. of NaCl ( m.wt 58.5 ) dissociates into 2 ions in solution so gives an osmotic pressure of 2 osmoles-the number of osmotically active particles is twice as great as when it was not dissociated

Question 14

NICE guidelines for HES infusion

Answer 14

• HES is only indicated for the treatment of low blood volume due to acute blood loss when crystalloids alone are not considered sufficient.
• Use of HES is contraindicated in:
• Sepsis, burns, kidney impairment or kidney function replacement therapy, intracranial or cerebral haemorrhage, critically ill patients (typically admitted to the intensive care unit), hyperhydrated patients, including patients with pulmonary oedema, dehydrated patients, severe coagulopathy, severely impaired liver function
• The maximum daily dose of HES is 30 ml per kilogram of bodyweight.
• Only use HES during the first 24 hours of fluid resuscitation treatment.
• Trauma and surgery: carefully weigh the expected benefit of treatment against the uncertainty of the long term safety of treatment. Consider other available treatment options.
• Monitor kidney function in patients receiving HES for at least 90 days. Stop HES treatment at the first sign of kidney injury.
• Stop HES treatment at the first sign of impaired blood clotting.
• Please continue to report suspected adverse drug reactions to HES or any other medicine via the Yellow Card Scheme