PerioperativeFluid & Electrolytes Management

Perioperative intravenous fluid therapy is an

area of care that is often left to junior doctorsLassen K. Brit J Surgery 2009; 96:123-24

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.The UK National Confidence Enquiry into Perioperative Deaths report has documented that a number of surgical patients die because of inappropriate fluid management by inadequately trained staff.

Questionnaires to 200 doctors (100 Group A; 50 Group B; and 50 Group C)

Group A: pre-registration house officers questioned within 10 days of starting their job; Group B 6-8 weeks; Group C surgical senior house officers.

Problems with Solutions

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.Only 50% prescribed the desired amount of potassiumAbout 26% prescribed > 2 L 0.9% saline/day.Less than 40% of respondents were given formal or informal guidelines on fluid and electrolyte prescribing on surgical firms

Knowledge relevant to fluid and electrolyte prescribing among surgical junior doctors is inadequateTeaching on the subject at both undergraduate and postgraduate levels does not prepare junior doctors for the task.

Results

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Body Fluid CompartmentsICF:55%~75%IntravascularplasmaX 50~70% lean body weightExtravascularInterstitial fluidTBWECF3/41/4Male (60%) > female (50%)Most concentrated in skeletal muscleTBW=0.6xBWICF=0.4xBWECF=0.2xBW

2/31/3

Fluid Compartments

Fluid shifts / intakes

Intracellular30 litres

Interstitial9 litres

IV 3 litresKidneys Guts Lungs Skin

Extracellular fluid - 12 litres

*The majority of our total body water is locked within our cells; this is the intracellular compartment. Bathing our cells, and occupying extracellular spaces such as the pleural cavity, joint spaces etc., is a smaller amount of interstitial water. Our intravascular compartment holds the smallest amount of water at around 3 litres ( a further 2 litres of red cells makes up our total blood volume ). The interstitial and intravascular compartments make up our extracellular space. Water moves freely between these compartments, but in our day to day use, fluids can only be given into, or taken from the vascular space. Fluid losses occur mainly from the vascular compartment as well. We lose water through our renal and gastrointestinal tracts, and this can be seen and measured. The water we lose from our skin and respiratory tract can not be measured with ease, and makes up our insensible losses. These amount to 500 ml a day in health ( on average ), and increase in sickness, particularly when febrile.

Water Intake and Output

Prospective AuditPerioperative fluid management106 consecutive patients6 months period54% patients developed at least one fluid related complicationLonger hospital stay

Walsh SR, et al. Int J Clin Practice 2007

Perioperative Fluid ManagementHow much should we infuse?

What fluids should we use?

Traditional TeachingA typical 70 kg adult

1 liter Normal Saline2 liters 5% Dextrose

Total Fluid: 3 litersTotal sodium: 154 mEqTotal Potassium: 0

Restricted versus Liberal

Amount of Fluid ?The debate goes on - - -

A Risky Situation ! !Risks of inadequate resuscitationLife-threateningNonfatalRisks of excessive hydrationLife-threatening Nonfatal

Restricted vs LiberalInconsistent resultsRestricted volumeImproved outcomes after minor surgeryDizziness, nausea and vomitingMajor surgeryPostoperative ileus?Hospital stay?Laparoscopic cholecystectomy

Anesth Analg 2007; 105: 465-74

Postoperative Fluid ManagementIntravascular volume deficitPreoperative fastingIncreased evaporative fluid lossIncreased third space shiftingVasoconstrictionAwake patientMaintenance of blood pressureAnesthesia inductionDecreased sympathetic toneOrgan dysfunction

Jacob M, e al. Lancet 2007; 369: 1984-86

Liberal Fluid AdministrationImproved postoperative pulmonary functionImproved exercise capacityGeneral well beingImproved nausea, dizziness and fatigue

Holte K et al., Annals of Surgery 2004;240:892

Preloading?OverestimationPreoperative deficitsInsensible lossesFluid bolusesNo major impact on anesthesia related hypotensionLiberal fluid regimenDecreased acute renal failure

Jacob M, et al. Lancet 2007; 369: 1984-86

Restricted Fluid AdministrationRandomized, multicenter study172 patients, 8 hospitalsElective colorectal resectionRestrictive versus standard perioperative fluid regimen

Brandstrup et al. Ann Surg 2003;238:641

Restricted Fluid AdministrationBrandstrup et al. Ann Surg 2003;238:641

Restricted GroupStandard GroupPostoperative complications3351Cardiopulmonary724Tissue healing1631Deaths04

Gynecological SurgeryRandomized study141 patients undergoing elective surgery30 mls/kg versus 10 mls/kgBetter results with liberal fluid useReduced nausea, vomiting and anti-emetic use

Magner et al. Brit J Anesthesia 2004;93(3):381

Clinical Implications of Excess FluidIncreased demand on cardiac functionIncrease in postoperative cardiac morbidity

Fluid accumulation in lungsPneumonia and respiratory failure

Excretory demands on kidneysInhibitory effects of anesthetics and analgesics

Holte K, et al. Brit J Anesth 2002; 89 (4): 622-32

IV Fluid OverloadDecrease muscular oxygen tensionImpaired gut functionCause general edemaPeripheral edemaPeriorbital edemaImpede tissue healing

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Clinical Implications Fluid RestrictionLactic acidosis

Compromised renal function

Multisystem organ failure

Perioperative Fluid ManagementHow much should we infuse?

What fluids should we use?

Fluid Electrolyte BalanceSurgical patients have special needsNil orallyAnesthesiaTraumaSepsis

Stress ResponseAntidiuresis and oliguriaVasopressinCatecholaminesRAASSalt and water retention even in presence of overloadAbility to excrete free water is limited

PHYSIOLOGICAL RESPONSE TO Stress - SurgeryStress - Anaesthesia

ADHAldosteroneReninRetention of H2O + Na+Loss of K+2-4 Days

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Sequestration of fluid from ECW35

30

25

20

15

10

5

% BODYWEIGHT

NORMAL ACUTE INJURY ELECT & IV Col PHASE OF RESOLUTIONICWIFPLI.V. fluidsDiuresisFormingSequestratedECFSequestratedECFResolvingSequestratedECF

3rd spaceKokko & Tannen Fluids & Electrolytes. WB Saunders 3 ed.p738

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Hyponatremia -Usually Excess Free WaterFree water replacement of isotonic lossesIncreased ADH secretionExcess solute e.g. glucose - intracellular water shifts to ECF (Dilutional)

Features - depends on rapidity

Acute drop below 120 weaknessfatigueconfusioncrampsnausea/vomitingheadache/delirium/seizures/comapermanent CNS damageHyponatremia -Usually Excess Free Water

Trends in Perioperative Fluid ManagementBefore 1960s fluid restriction (Moore)After 1960s fluid liberalization (Shires)1970s invasive monitoring1970s - dopamine1970s crystalloid/colloid controversy (TMTN)1980s recognition of glucose risk (Lanier)1980s cerebral effects of tonicity (Todd)Present red states (Arieff, Kehlet, Brandstrup) vs. blue states (Holte, Kehlet)

Fluid Distribution in a 75-kg AdultCapillary Endothelium

Plasma3LInterstitial Compartment10LIntracellular Compartment30LBlood Cells 2L

*1. 5L, intracellular/extracellular component2. capillary endotheliumNa, Kion3. colloid, crystalloid, glucosefluiddistributecompartmentPVE:Glucoseall compartment, 7%plasmaSaline 3/15, 20%Ideal colloid: large molecules that do not escape from the circulation, 100%

fluid replacementcompartment fluidadverse effects

The Oliguric PatientSignificant intravascular hypovolemia?

Clinical signs of intravascular volume

Interpretation of urine output

Urine outputis not a reliable marker of hydration status in postoperative PatientsStress-induced ADH and Aldosterone cause water retention

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Metabolic Consequences of Saline Infusions

Saline Infusion Produces Dose-Dependent Hyperchloremic Acidosis

McFarlane et al. Anaesthesia 1994;49:779Scheingraber et al. Anesthesiology 1999;90:1265Waters et al. Anesthesiology 2000;93:1184Rehm et al. Anesthesiology 2000;93:1174Liskaser et al. Anesthesiology 2000;93:1170

(Ab) Normal SalineChloride overload along with sodium overloadHyperchloremiaRenal vasoconstrictionReduced GFRFurther reducing kidney ability

(Ab) Normal SalinePersistent hyperchloremia after saline infusions reflect the lower Na:Cl ratio in saline (1:1) ---Infusions of 0.9% saline produces a significant hyperchloremic acidosis --The decrease in the anion gap is more pronounced with saline ---

Awad S, et al. Clinical Nutrition 2008; 27: 179-188

Potassium DepletionProtein catabolism

RAAS activity

Decreased ability of kidneys to excrete sodium

.Daily Sodium requirement for a healthy 70 kg man (desired answer highlighted)

mmol/dayGroup A (%)Group B (%)Group C (%)180142Dont know372018

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.Daily potassium requirement for a healthy 70 kg man (desired answer highlighted)

mmol/dayGroup A (%)Group B(%)Group C (%)801-2Dont know1488

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Exogenous PotassiumIV fluidsSterile, closed system

Exogenous additionOpen systemContaminationInadequate mixing

*IV fluids have very stringent manufacturing criteria. They are sterile and constitute a closed system. Exogenous addition makes it an open system that can cause contamination. Moreover, adequate mixing is usually a problem.

Layering EffectPotassium is added to IV fluidsDensity differencesConcentrated layer of potassium formsSerious effects on the heart

*Potassium is commonly administered by adding it to a suitable infusion fluid. However, if the solutions are not thoroughly mixed, a concentrated layer of the additive may form due to a difference in the densities of the two solutions. Such a mixture, if administered, can have a serious effect on the heart.

POTASSIUM CHLORIDE IS

PARTICULARLY PRONE TO THIS

LAYERING EFFECT

British National FormularyMarch 2009

*Potassium chloride is particularly prone to this layering effect. This is the form that is usually employed for potassium replacement.

Control of Concentrated Electrolyte SolutionsStatement of Problem and Impact:

Concentrated potassium chloride has been identified as a high risk

medication by organizations in Australia, Canada, and the United

Kingdom of Great Britain and Northern Ireland (UK)Patient Safety Solutions| volume 1, solution 5 | May 2007

EACH DROP HAS THE SAME CONCENTRATIONHomogenized SolutionPlabolyte-M and Plabolyte-40

British Consensus Guidelines

Intravenous Fluid Therapy

for Adult Surgical Patients(http://www.asgbi.org.uk/en/surgical resources and documents/)

Pre-Operative FastingIn patients undergoing elective surgery clear non-particulate oral fluids should not be withheld for more than two hours prior to the induction of anaesthesia.Preoperative administration of carbohydrate rich beverages 2-3 h before induction of anaesthesia may improve patient well being and facilitate recovery from surgery.

Bowel PreparationRoutine use of preoperative mechanical bowel preparation is not beneficial and may complicate intra and postoperative management of fluid and Electrolyte balance. Its use should therefore be avoided whenever possible.Where mechanical bowel preparation is used, fluid and electrolyte derangements commonly occur and should be corrected by simultaneous intravenous fluid therapy with Hartmanns or Ringer-Lactate/acetate type solutions.

RecommendationsBalanced salt solutions should replace 0.9% salineTo meet maintenance requirements, adult patients should receive sodium 50-100 mmol/day, potassium 40-80 mmol/day in 1.5-2.5 litres of water by the oral, enteralor parenteral route (or a combination of routes).

Balanced Salt Solutions

RingolactRingolact-D0.9% SalineDextrose SalineSodium130130154154Chloride108108154154Potassium44 - - - - - -Calcium2.72.7 - - - - - -Bicarbonate2823 - - - - - -Dextrose- - -50 - - - 50

Conclusion

Goal Directed Fluid TherapyNon-bowel surgery

more liberal fluid improves symptoms

Goal Directed Fluid TherapyReplacementRingolactRingolact-D

MaintenancePlabolyte-MPlabolyte-40

Requirements in a 60 kg patient

5% D/W: 2 LD/Saline:1 L5% D/W: 1 LD/Saline:2 LPlabolyte-M 3 LDailyRequirementSodium154 mEq308 mEq180 mEq60-120 mEqChloride154 mEq308 mEq180 mEqAs neededPotassium0060 mEq60-120 mEqCalcium009 mEq300 mEqBicarbonate0069 mEqAs neededDextrose150150150Variable

*Lets come to the daily requirements in an average weight individual. The daily potassium requirement of potassium is about 60-120 mEq. We can see the difference when different fluid regimens are administered. The most physiological of these regimens is that of Plabolyte-M.

Meeting Daily Requirements

K+ (mEq)Na+ (mEq)Cl- (mEq)HCO3- (mEq)Plabolyte-M (2 liters)4012012046Plabolyte-40(1 litre) +Plabolyte-M(2 litres)8012016046

*However, if we administer one liter of Plabolyte-40 and 2 liters of Plabolyte-M, we have an ideal situation.

A Little Ignorance ..........can go a Long Way

Thank you for your Attention

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*The majority of our total body water is locked within our cells; this is the intracellular compartment. Bathing our cells, and occupying extracellular spaces such as the pleural cavity, joint spaces etc., is a smaller amount of interstitial water. Our intravascular compartment holds the smallest amount of water at around 3 litres ( a further 2 litres of red cells makes up our total blood volume ). The interstitial and intravascular compartments make up our extracellular space. Water moves freely between these compartments, but in our day to day use, fluids can only be given into, or taken from the vascular space. Fluid losses occur mainly from the vascular compartment as well. We lose water through our renal and gastrointestinal tracts, and this can be seen and measured. The water we lose from our skin and respiratory tract can not be measured with ease, and makes up our insensible losses. These amount to 500 ml a day in health ( on average ), and increase in sickness, particularly when febrile.*

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*1. 5L, intracellular/extracellular component2. capillary endotheliumNa, Kion3. colloid, crystalloid, glucosefluiddistributecompartmentPVE:Glucoseall compartment, 7%plasmaSaline 3/15, 20%Ideal colloid: large molecules that do not escape from the circulation, 100%

fluid replacementcompartment fluidadverse effects*

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*IV fluids have very stringent manufacturing criteria. They are sterile and constitute a closed system. Exogenous addition makes it an open system that can cause contamination. Moreover, adequate mixing is usually a problem.*Potassium is commonly administered by adding it to a suitable infusion fluid. However, if the solutions are not thoroughly mixed, a concentrated layer of the additive may form due to a difference in the densities of the two solutions. Such a mixture, if administered, can have a serious effect on the heart.*Potassium chloride is particularly prone to this layering effect. This is the form that is usually employed for potassium replacement.*Lets come to the daily requirements in an average weight individual. The daily potassium requirement of potassium is about 60-120 mEq. We can see the difference when different fluid regimens are administered. The most physiological of these regimens is that of Plabolyte-M.*However, if we administer one liter of Plabolyte-40 and 2 liters of Plabolyte-M, we have an ideal situation.