Problems with Solutions GUIDANCE FOR IV FLUID AND ELECTROLYTE PRESCRIBING IN FIFE Fluid Prescription Working Group May 2012.

Problems with SolutionsGUIDANCE FOR IV FLUID AND

ELECTROLYTE PRESCRIBING IN FIFE

Fluid Prescription Working Group May 2012

WHY HAVE WE PRODUCED THIS GUIDANCE?Fluid prescribing is done poorly.Certain problems can arise:

Too wet

Too dry

LACK OF EDUCATION AND ATTENTION TO DETAIL

IT’S COMPLICATED!Please don’t write up fluids on

patients you know nothing about without looking at various

parameters (to be explained below)

The backgroundNational reportsRecent national guidelinesNational meetingsDoctors’ level of knowledge and

applicationObservation of practiceLocal audits

Abnormal SalineIs there a problem nationally?

19991999 Patients are dying as a result of infusion of

too much or too little fluid by

inexperienced staff.

New doctors have inadequate knowledge

and sub-optimal prescribing skills

Fluid prescription must be given the same

status as drug prescription.

Poor fluid management contributed to around half of the deaths

SASM Report 2008

Errors in fluid prescription are common in hospital practice and are dangerous

Shaifee et al QJM 2003

17% of postoperative patients develop morbidity directly related to fluid prescription

Walsh et al Ann Roy Coll Surg Engl 2005

Has anything changed since 1999?

Fluid PrescribingFluid Prescribing

Left to the most junior member of the team Wide variability in prescribing practices About 26% prescribed > 2L 0.9% saline/day

Lobo et al Clin Nutr 2001

Fife 2012Brief survey of juniors in HDU and anaesthesiaPoor knowledge of maintenance requirementsPoor knowledge of Na/K requirementsNo system for calculating peri-operative fluid

requirements

Fluid therapy is often poorly taught, poorly understood and poorly done

Some examples75 year-old lady Post Hartmanns, 55kgNot well 5 days post-op: SOB, oedematousOn TPN AND IV fluids : >3L/dayNa 130Lungs wetIleusGross peripheral oedemaNeeds fluid restriction; stop IV fluidsGentle diuresis

Overload in Orthopaedics80 year-old man: Mild angina and mild aortic stenosis,

independent, N U&Es, 60kg Op delayed for 6 days, fasted on and off for 6 days. Minimal

food intake.16.5 litres IV fluid in 6 days (requirement approx 1800ml/day =

10.8l), Na day 5 =128Day 7 – surgery – still fasting, more IV fluid, D 8 Na 123 – cardiac failure, pulmonary oedema, angina.

Frusemide++ D 9 creatinine 300, urea 10. All iatrogenicPREVENT!

Excess loss/ Inadequate provision80 yrs, post-Hartmanns – developed high NG losses, 4

litres/day for 1 weekFluid balance on ward not properly addressed Developed severe alkalosis on the ward: pH 7.61 and severe dehydration, low Na/KAdmitted to ICU for two days for correction before he

could go back to theatre: anastomotic leak discoveredOrthopaedics 80 yr old, 60kg with Alzheimer’s: #NOF

3 litres/5days (maintenance: 9 litres)

4 Audits in FifeLots of patients not getting much fluid,

especially in orthopaedicsSome got far too much, especially in

surgery Not enough potassium – all areasFar too much sodium – all areasBUT: Education improves practice

SHDU Results2/3 of patients got too much sodium, in some

cases excessively so (> 800mmol Na on one occasion)

On 1/3 of patient–days roughly (+/- 500ml) the right volume of fluid was given, on 1/3 too much, and on 1/3 too little

Fewer than 1/2 patients received enough potassium. Excess losses were generally not replaced

Anaesthetic audit: ResultsPatients with higher intra-operative fluid

volumes experienced more post-op complications as well as more PONV (chest infections, arrhythmias, ileus, low BP, confusion)

High volumes of Hartmanns are given peri-operatively and it is often used as a maintenance fluid post-op – it is not one

What should we do?Lessons from physiology

The The rightright amount amount

of the of the right right fluid fluid

at the at the rightright time time

ModerationFD Moore & GT Shires, Ann Surg 1967

The objective of medical care is

restoration to normal physiology and

normal function of organs, with a normal

blood volume, functional body water and

electrolytes. This can never be

achieved by inundation.

In the distant past...Wounded/sick animal or personNo food or water may be available for 24-48

hours until he drags himself to the waterholeRetains fluid by oliguria and anti-diuresis,

trying to maintain blood volumeStress response to trauma mediated by Renin

angiotensin aldosterone system (RAAS), ADH and catecholamines

Catabolic Response to Injury/IllnessSodium and water retention (ADH, RAAS, catecholamines)

Capacity of kidneys to excrete water and Na is impaired

Increased potassium excretion (due to RAAS activity and protein

catabolism)

Decreased urine output

Sicker patients have poor concentrating ability – poor excretion of

Na and Cl load

Catabolic patients produce more urea which is excreted in

preference to Na and Cl and this increases water retention

What do we often do? We give lots of fluid, lots of sodium chlorideKidneys can’t excrete sodium loadChloride causes renal vasoconstriction and exacerbates

fluid retention and oedemaLeaky capillaries in sick patients exacerbate RAAS/ADH

activity and oedema worsensWe don’t give much potassiumPotassium depletion reduces ability to excrete sodiumWe don’t give many caloriesCalories help the cells to maintain fluid homeostasis

Too wet

Salt & Water overload: Physiological ConsequencesDecreased renal blood flow and GFRIntra-mucosal acidosis Prolongation of gastric emptying timeIleus (+ low K+, opioids, poor mobility, pain)Hyperchloraemic acidosisWeight gainLow serum sodium - ? More givenCellular dysfunction

Salt & Water Overload: clinical

Peripheral oedema

Gastro-intestinal

oedema: N & V

Impaired cardiac

function: Pulmonary

oedema/ARDS

CCF/arrhythmias

Confusion

Delayed

mobilisation

Pressure sores

Increase in DVT

Too dry

Salt & Water DepletionReduced stroke volume – poor organ

perfusion, hypotension, fallsImpaired renal perfusion - ARFIncreased viscosity of mucusReduced saliva - discomfortIncreased blood viscosity - clots

Problems with SolutionsPROBLEMS WITH SALINE

The Origins of 0.9% SalineNot a physiological fluid – based on a mistake

by a physiologist called Hamburger in 1830sHe thought concentration of salt in blood was

0.9% but it is nearer 0.6%0.9% NaCl is not a maintenance fluidIt has certain specific uses

The Abuse of Normal Salt The Abuse of Normal Salt SolutionSolution

George H. Evans, JAMA 1911George H. Evans, JAMA 1911

““One cannot fail to be impressed with the danger One cannot fail to be impressed with the danger

of the utter recklessness with which salt solution of the utter recklessness with which salt solution

is frequently prescribed, particularly in the is frequently prescribed, particularly in the

postoperative period…”postoperative period…”

“…“…the disastrous role played by the salt solution is the disastrous role played by the salt solution is

often lost in light of the serious conditions that often lost in light of the serious conditions that

call forth its usecall forth its use.”.”

The Times, 28 January 2000

Hartmanns solution/Ringer’s LactateDiscovered independently by Hartmann and

Ringer‘Balanced’ solution i.e. More like the

composition of plasma, has lactate as a bufferLess Na and Cl load and the Na load is more

effectively excreted with less fluid retention (there still is some), less acidosis and less effect on albumin and Hb than saline

It is a good REPLACEMENT fluid when a patient has lost body fluids

EvidenceExperiments have shown that in healthy

volunteers, infusion of 2 litres of saline results, after 6 hours, in weight gain due to fluid retention, a drop in albumin and Hb, acidosis, poor uop and retention of sodium. 2 litres of Hartmanns is better than saline for all of these parameters, and dextrose is the best in terms of lack of fluid retention and uop.

This fluid retention is worse in sick patients.Dextrose-containing maintenance fluids are best

but ensure not too much is given – the right amount!

Post -opOther studies have shown that patients

having significant amounts of unnecessary fluid peri-operatively have more complications e.g. poor wound healing, chest infections, slow mobilisation, nausea and vomiting

The fluid given must be tailored to each patient’s situation.

There is a very narrow range for optimal fluid load

NHS FifeGuidelines for intravenous fluid and

electrolyte prescription in adultsGroup: M.McDougall, S. Oglesby,

S. Bennett, A. Doyle, K. Buck, A. Sengupta, L. Clark, J. Hadoke, A. Timmins, K. Spurgeon, M. Clark, A. Rahman, L. Reekie.

Based on GIFTASUP guidelines

British Consensus Guidelines on Intravenous Fluid Therapy for Adult Surgical Patients

GIFTASUPJeremy Powell-Tuck (chair), Peter Gosling, Dileep N Lobo, Simon P Allison, Gordon L Carlson,

Marcus Gore, Andrew J Lewington, Rupert M Pearse, Monty G Mythen

BAPEN Medical, the Association for Clinical Biochemistry, the Association of Surgeons of Great Britain and Ireland, the Society of Academic and Research Surgery, the Renal Association and the Intensive Care Society.

1.Balanced salt solutions e.g. Ringer’s lactate/acetate or Hartmann’s solution should replace 0.9% saline when crystalloid resuscitation or replacement is indicated except in hypochloraemia 1b

2.Solutions such as 4%/0.18% dextrose/saline and 5% dextrose are important sources of free water for maintenance. Excessive amounts may cause hyponatraemia, especially in the elderly 1b

Recommendation 3To meet maintenance requirements,

patients should receive sodium 50-100 mmol/day, potassium 40-80 mmol/day in 1.5-2.5 litres of water by the oral, enteral or parenteral route (or a combination of routes).

Additional amounts should be given to correct deficit or continuing losses. Careful monitoring should be undertaken using clinical examination, fluid balance charts and regular weighing, when possible.

Evidence level 5

Questions to ask before prescribing fluid

Does my patient need intravenous fluid?

Why does my patient need intravenous fluid?

How much and which fluid does he need?

Does he need fluid?May be drinkingMay be on NG feed/TPN – both of these

contain fluid which counts as maintenanceMay be receiving many drug infusions e.g.

antibiotics/paracetamol – can amount to 1+ litre/day

He may only need a bit of maintenance fluidThis calculation should be done for each

patient

Why does he need fluid?Maintenance –water and

electrolytes To supply the daily needs –

(e.g. 4% dextrose/0.18%saline/KCl)Replacement To replace ongoing losses know the content of the fluid! Resuscitation - e.g.colloid/bloodTo correct an intravascular or

extracellular volume deficit

MAINTENANCE

If you were on a desert island, would you drink from the sea or a stream?

0.9% saline is not a maintenance fluid

Daily Requirements (GIFTASUP)

Water 25-35 ml/kg (30)

Sodium approx 1 mmol/kg

Potassium approx 1 mmol/kg

Calories minimum 400 Calories

(i.e. 100 g dextrose)

(calories help to deal with electrolytes normally)

Average Daily Requirements70 kg man needs: 2100 ml H2O 70 mmol Na+

70 mmol K+

70 mmol Cl-

50kg man needs 1500 ml H2O 50 mmol Na+

50 mmol K+

50 mmol Cl-

Properties of Commonly Used Properties of Commonly Used Crystalloid SolutionsCrystalloid Solutions

SolutionSolution Electrolyte Electrolyte ContentContent

(mmol/l)(mmol/l)

OsmolalitOsmolality y

(mOsm/k(mOsm/kg)g)

pHpH

0.9% NaCl0.9% NaCl NaNa++ 154 154 ClCl- - 154154 308308 5.05.0

Dextrose Dextrose (4%)-Saline (4%)-Saline (0.18%)(0.18%)

NaNa++ 31 31 ClCl- - 3131 286286 4.54.5

5% 5% DextroseDextrose

NilNil NilNil 280280 4.04.0

Hartmann’s Hartmann’s solutionsolution

NaNa++ 131 131

KK++ 5 5

CaCa++ 2 2

ClCl- - 111111

HCOHCO33- - 2929

276276 6.56.5

MAINTENANCEPrescribe maintenance if not drinking >6hrs 4%/0.18% dextrose/saline with 20mmol potassium

in 500ml, or 40mmol in 1 litre (1 litre is cheaper). Or no potassium

Prescribe in ml/hr (see table) via a pump.The correct volume of this by weight per day for

maintenance will provide roughly the correct amount of sodium and potassium for each patient. Maximum 100ml/hr to avoid hyponatraemia. Do not prescribe x hourly

PUMPSAt present there are just about enough but

distribution is a big problemWe are hoping to get more and distribute them

better in the hospitalEach ward will have their own so it is important

to keep hold of them and get them back if they leave

If a patient is on dex/saline they really should have a pump to ensure the correct rate is given.

If a patient is on fluids of any kind for >6 hours they should have a pump

PotassiumA normal serum potassium is not an indication

that the patient does not need potassium – it just means that their stores haven’t run out yet.

A low potassium means that losses are high and body stores very low.

A high potassium may be drug related but commonly is due to acute renal failure – monitor U&Es and do not give extra K.

Remember that TPN, NG feed and food contain K

SodiumWe all need some. However most drugs

contain sodium so we don’t need to give a lot in fluids unless the patient is losing it.

Causes of a low Na – too much fluid (commonest cause in hospital!) – fluid restrict

SIADH inappropriate antidiuretic hormone secretion– pneumonia, brain pathology

High Na loss – usually upper GI losses – tend to be obvious

Fluid overloadRecognise clinical signsMay need fluid restrictionCareful fluid balance and monitoringGentle diuresis – beware of precipitating ARF

in a patient whose kidneys may not be working efficiently

REPLACEMENTLosses should be accounted for with

replacement fluid: balanced solution: Hartmanns (Plasma Lyte 148 – may become available, has Mg, no Ca, acetate not lactate)

Work out how much patient is losing and replace this with Hartmanns – better to calculate retrospectively and replace.

Fluid prescriptions for losses must be reviewed regularly and updated.

LOSSESUpper GI loss: stomach, small bowel

ileostomy/fistula/bile leak: high Na and Cl content – may become hypochloraemic and alkalotic – appropriate to use 0.9%NaCl

Lower GI loss: diarrhoea - lose lots of water and potassium: Hartmanns is appropriate to replace + extra potassium (guide in booklet)

How much fluid does he need?Weight for maintenance 30ml/kg/24hrs

History, fasting, losses, sepsis, fluid balance charts

Clinical status, current losses, fluid intake, urine output

Electrolytes, Hb (may be raised in dehydration)

ExclusionsPaediatric patients: consult paediatricianDiabetic patients: follow diabetic guidelinesHead injury patients: avoid dextroseRenal failure patients: consult senior doctorObstetrics: consult obstetric team in complex

patients

Resuscitation FluidFor severe dehydration, sepsis or blood causing

circulatory hypovolaemia and hypotension

Use Hartmanns or colloid, blood/O Negative in emergencies

May need critical care referral for inotropic support/ invasive monitoring

Criteria for Critical Care Referral – on guidance

Algorithm for fluid challenges

Fluid challenge250ml colloid or Hartmanns over 2-5 minsDon’t go away!Looking for improved UOP, improvement in

perfusion/BP/HRCan be repeated – if patient still looks

hypovolaemic after 2 litres senior help is required – may need inotropes and ICU

Very few patients will go into LVF with 250ml fluid (less than a can of coke!)

ColloidsGelofusine – currently in 0.9%NaCl but will

soon be in a balanced solutionAlbumin 4.5%Starch – for specialised use in theatre/ICUSome controversy about which is bestFor your purposes don’t worry about this!

SummaryRemember the three questionsDoctors should take time and

consult senior if unsurePatients on IV fluids need regular

U&EsPatients should be allowed food and

drink as soon as possible

The The rightright amount amount

of the of the right right fluid fluid

at the at the rightright time time