1. Presented by: Dr. Meenal Aggarwal Moderator: Dr. S. Singh
Intravenous Fluids
Presented by: Dr. Meenal Aggarwal
Moderator: Dr. S. Singh

2. Basic Physiology Total body water:
Pre mature infant : 80% of lean B.W.
Term infant: 70 – 75%
Adult male : 60% (more muscle)
Adult female : 50% (more fat)
TBW(60) : ECF (20)(plasma + interstitial fluid) + ICF (40)

3. In children : higher ECF (contributes to higher B.W.)
T.B.W decreases with age (mainly d/t loss in ICF)
Composition of body fluids:
ICF : K+ , Mg2+ Organic phosphate esters (ATP, Creatine phosphate, phospholipids)
ECF : Na+ , Cl- , HCO3-
Compartments are separated by semi-permeable membrane
Water freely passes through it and maintains an osmotic equilibrium
Daily fluid requirement: Urine output + insensible losses (700ml)

4. Fluid Homeostasis in Body
Volume regulation
Important for adequate tissue perfusion
Effective circulating vol
Sensed by Baroreceptors
Carotid sinus, aortic arch
Afferent glomerular arterioles
Atria, ventricles
Act via
Sympathetic nervous system
Renin-Angio-aldo
Natriureic hormones (ANP, BNP)
Argenine vasopressin

5. Fluid Homeostasis in Body cont…
Osmoregulation
Essential for cell function
Plasma osmolarity
Sensed by Osmoreceptors
In hypothalamus (paraventricular, supraoptic nuclei)
Act via
AVP
Thirst
Normal Plasma Osmolality = 2 X [Na+] + [BUN/2.8] + [Glu/18]
Normal value = mosm/Kg

6. Fluid Balance in Perioperative Period
Goal: Euvolemia, normal oxygen carrying capacity and normal electrolyte distribution
Challenges: because of:
Fasting status
Losses (bleeding, evaporation, 3rd space losses)
Effects of neuraxial anesthesia (sympatholysis)
Ineffective thirst (d/t diminished alertness after GA/ sedation)

7. Assessment of Fluid Balance
Preop History: Medical illness, preop vol status
Surgery/ Intervention: Type of surgery, blood loss/ 3rd space
Anaesthesia: Type, duration, Fluid replacement given, BT, Type of monitoring, intra-op vital trends
Current clinical condition:
GPE: Weight, Skin and tongue, sensorium, pulse, BP
Urine output : Should be >0.5-1ml/kg/hr
Monitoring: Pleth, IBP, C.O. measurement, CVP, PCWP, TEE
Lab: S.urea, S.creat, urinary Na, ABG (pH, lactate, Hct), VBG

8. Intra Venous Fluids I V Fluids Crystalloids Unbalanced NS, 3% S, N/2 S
D5, D10, D 25
Balanced
Ringer Lactate
Isolyte P
Colloids
Gelatins
Dextrans
Starches (HES)
Human Albumin

10. Normal Saline (0.9% NaCl) Composition : Na+ 154 meq/L, Cl- 154 meq/L
Osmolarity: 308 mOsm/L (Isotonic), pH : 6.0
Distributed mainly in ECF, so very useful in hypovolemic shock
Only 25% of the total fluid given remains intravascularly, 3-4 times volume of fluid lost is required for replenishment
Indication:
Salt and water deplation as in diarrhoea, vomiting, excessive sweating
Tt of alkalosis (e.g. vomiting) with dehydration, May induce non anion gap hyperchloremic metabolic acidosis (as high chloride l/t dec plasma HCO3- content)

11. Normal Saline (0.9% NaCl) cont..
Hypovolemic shock
Hyponatremia
Initial fluid therapy in DKA
Fluid challenge in pre-renal ARF
Irrigation fluid
Hypertonic Saline (3-7.5%): used in therapy of severe symptomatic hyponatremia, for resuscitation in patients of hypovolemic shock
Caution: should be administered slowly, preferably through central venous catheter because can l/t hemolysis

12. Normal Saline (0.9% NaCl) cont..
Contraindication:
Cautious use in HTN or preeclamptic patients, CHF pts, renal ds, cirrhosis
If dehydration is preset along with hypokalemia (need to add K+ or else NS alone will aggravate K+ deficiency)
Used cautiously in patients with renal derangements (chloride l/t decreased renal blood flow)
Note: As it can l/t metabolic acidosis, should not be mistakenly interpreted as lactic acidosis in cases of impaired circulation

13. 5% Dextrose Composition : Glucose 50 g/L (or 25 g/vac)
Osmolarity: 252 mOsm/L (hypotonic), pH : 4.5
Only 8% of the total fluid given remains intravascularly (glucose gets metabolised when enters body, so free water) best for correcting intracellular dehydration
Provides 170 Kcal/ L
Indications:
Tt of dehydration d/t inadequate water intake/ excessive water loss
To provide calories
Pre- and post-op replacement fluid

14. 5% Dextrose cont…
Tt and prevention of ketosis in starvation/ diarrhoea/ vomiting
Correction of hypernatremia ( with frusemide)
Contraindications:
Cerebral edema/ Neurosurgical procedures/ Acute ischemic stroke
Hypovolemic shock (also osmotic diuresis)
Careful administration during hypernatremia
Along with blood transfusion (hemolysis, clumping)
Severe hyperglycemia/ uncontrolled DM

15. Ringer’s Lactate
Composition : Na= 130mEq, K= 4mEq, Ca= 3mEq, Cl= 109mEq, lactate= 28 mEq per litre of RL
Osmolarity: 274 mOsm/L (hypotonic), pH : 6.5
Most physiological fluid (can be given in large quantities without risk of electrolyte imbalance)
Lactate is converted to HCO3 in the liver (correction of metabolic acidosis)
Indications:
Tt of severe hypovolemia rapidly with large fluid volume
Diarrhoea induced hypovolemia with hypokalemic metabolic acidosis

16. Ringer’s Lactate cont…
Postoperative fluid replacement
In DKA, RL provides free water so corrects metabolic acidosis, also gives K (controvertial regarding lactate)
Contraindications:
Liver ds, severe hypoxia and shock (impaired lactate metabolism)
In severe CHF with lactic acidosis
Addison’s disease
Even in severe metabolic acidosis (impaired lactate conversion)
In vomiting or NG aspiration (metabolic alkalosis, RL worsens)
Along with BT (Ca combines with citrate, forms clots), binds drugs (thiopentone, amphotericin, ampicillin, EACA)

17. Isolyte-P
Composition : Glu= 50 g, Na= 25mEq, K= 20mEq, Cl= 22mEq, acetate= 23 mEq HPO4= 3 mEq, Mg= 3mEq per litre
Designed to suit maintenance requirement of children (need more water)
Can be used In adults where more water required (hypernatremia)
Indications:
Maintenance fluid in children and infants
Excessive water loss/ inability to conc urine (DI)
C/I:
Hyponatremia, hypovolemic shock (less Na, More K, glucosuria)
Renal failure

18. Plasma-lyte
Composition : Na= 140 mEq, K= 5 mEq, Cl= 98 mEq, acetate= 27 mmol, gluconate 23 mmol, Mg= 1.5 mmol per litre
Produces a metabolic alkalinizing effect (acetate and gluconate metabolize to CO2 and H2O using H+ ions)
Indications:
Fluid replacement
For alkalinization
Caution:
CHF, Edema with Na retention
Renal failure and metabolic alkalosis

19. Sterofundin
Composition : Na= 145 mEq, K= 4 mEq, Cl= 127 mEq, Ca= 2.5 mmol, acetate= 24 mmol, Malate 5 mmol, Mg= 1 mmol per litre
pH: , osmolarity= 309 mosm/L
Indications:
Fluid replacement in isotonic dehydration
For alkalinization
Caution:
CHF, Edema with Na retention
Renal failure/ hyperkalemia and metabolic alkalosis

20. Hydroxyethyl starches
Modified natural polysaccharides similar to glycogen
To delay α-amylase breakdown: natural starches are substituted with hydroxyethyl groups
Classified into: high (hexastarch), medium (pentastarch) and low (tetrastarch) substitution. High Molar substitution delays degradation
Plasma expanding effect depends on the concentration solution
Advantages:
High hemodilutional capacity
Vascular resistance is reduced by lowering blood viscosity (beneficially influence tissue perfusion)

21. Hydroxyethyl starches cont…
Disadvantages:
Decrease levels of vWF and factor VIII activity, impair platelet function, induce platelet damage (apparent when >1500ml given within 24hrs)
Renal dysfunction (hyperviscosity of urine in dehydrated pts)
Pruritis may occur d/t extravascular deposition of starch
Allergic reactions (although lowest c/f other colloids)
Clearance takes over several weeks (although oncotic activity is lost after 24hrs)

22. Gelatins (Haemaccel)
Produced by degradation of bovine collagen and chemical modifications
Commercially available preparations: 3.5%-5.5%
Adv:
Average molecular weight: 30-35 kD, small molecular weight, rapidly cleared from the bloodstream by glomerular filtration (80%)
Volume effect %
Do not accumulate in the body, have no dose limitations, almost no adverse effects on the kidneys

23. Gelatins cont… Disadv:
Hemostasis could be impaired (interference with coagulation factors, disturbance in the quality of fibrin polymerization)
Bovine origin (hypothetical potential of transmitting prion diseases)
Most frequent incidence of allergic reactions (6 times c/f HES)
Cleared rapidly so repeated infusions of gelatins are necessary to maintain adequate blood volume

24. Dextrans
Biosynthesized from sucrose by the bacterium Leuconostoc mesenteroides
Dextran 40 and dextran 70 (molecular weights of 40 and 70 kD)
Adv:
Molecules less than 50 kD are rapidly eliminated by the kidneys
Decreases blood viscosity, improved microcirculatory blood and tissue perfusion
Used by vascular and plastic surgeons to assist in keeping microvascular anastomosis patent
Dextran 70: generally preferred for volume expansion
Dextran 40: improve blood flow in the microcirculation

25. Dextrans cont… Disadv:
Induces a dose-dependent hyperfibrinolysis, decreased levels of vWF and associated factor VIII (VIII:c) activity, Max daily dosing: 1.5g dextran/ kg body wt
Coat red cells (interfere with cross matching, inc ESR)
Impaired renal function (tubular obstruction, swelling, and vacuolization of tubular cells due to hyperviscous urine)
Severe anaphylactic reactions (Prevention: dextran 1 (Promit), a low-molecular-weight hapten, administered few minutes before any dextran infusion)

26. Human Albumin Purified from pooled human plasma
Commercially available as a 5% (iso-oncotic), 20% & 25% (hyperoncotic) solution
Heated and sterilized by ultrafiltration, so risk of bacterial or viral disease transmission eliminated
Functions of albumin: maintaining the plasma oncotic pressure, transport protein, plasma buffer
Predictor of mortality risk in patients with acute and chronic illness (for each 2.5 g/L decrement in serum albumin concentration the risk of death increases by 24% to 56%)
5% albumin: 70% effective, effect lost in 12 hrs

27. Human Albumin cont… Uses:
Acute restoration of an effective circulating volume due to hemorrhage
Acute management of burns
Hypoproteinemia
Disadv:
High cost
Even detrimental in burns, hypoproteinemic pts.
Allergic reactions (equal to HES)

28. Colloid vs Crystalloid
For crystalloids: inexpensive, adverse effects are rare or absent, no renal impairment, minimal interaction with coagulation other than dilution, no tissue accumulation, no allergic reactions
For colloids: much better volume-expanding properties, minor edema formation, improved microcirculation
When compared neither type of fluid provided a survival benefit
So in patient with hypovolemia d/t dehydration (uniform loss of ECF), crystalloids are benefecial
In patients with hypovolemia secondary to hypoalbuminemia, colloids benefit the patient more.

30. Balanced vs Unbalanced Solutions
Large volume resuscitation with normal saline causes hyperchloremic metabolic acidosis (l/t organ hypoperfusion, increased morbidity, especially gastrointestinal, neurologic, renal damage, blood loss)
Buffered formulations (RL, Isolyte P) maintain a higher plasma pH and less chloride load, fewer incidences of hyperchloremic metabolic acidosis, low concentration electrolytes l/t reduction in postoperative morbidity.
Balanced crystalloid solutions are preferred in the perioperative period
Colloids suspended in balanced solutions now available, are better

31. Maintenance Fluid therapy
Normal ongoing losses in 70 kg man: ml/day
Fluid to be given calculated acc to Holliday & Segar formula”4-2-1”
Best maintenance fluid: balanced isotonic crystalloid (RL) untill the patient is NPO
Best estimation of fluid requirement is made by weighing the patient daily
Neuraxial anesthesia: Preloading with ml fluid appears to temporarily increase preload and C.O. without consistently increasing arterial B.P. or preventing hypotension.

32. Replacement Fluid therapy
Bleeding/ 3rd space loss/ Evaporation/ Sweating
Assessment: Estimate/ measure + Clinical examination + laboratory data
Type of fluid depends on the type of fluid lost or any electrolyte imbalance already present
Rate of administration: Arbitrary, depends on severity of deficit (diff in case of hyper/hypo Na)

33. Post Operative Fluid
Aim: BP > 100/70mm Hg, Pulse <120, Urine 30-50ml/hr, normal temperature, respiration, sensorium
When to give:
Usually for minor surgeries (no gut handling) started orally 4-6 hrs postop.
In Major surgeries( no gut handling e.g. THR/ cardiac) hrs of IV fluids
When intestinal resection: needs few days of IV fluids

34. Post Operative Fluid cont…
Routine postop orders for fluids for 3 days:
First 24 hrs: 2litre D5 or 1.5litre D ml NS (except neurosurgical patients, major surgeries)
2nd post op day: 2 litre D5 + 1litre NS
3rd postop day: Same mEq KCl
Modified according to individual case

35. Preferred fluid therapy
In Vomiting: (Hypovol, HypoK, HypoCl, Meta alk) NS
In Diarrhoea: (Hypovol, HypoNa, HypoK, HyperCl, Meta Acid) RL & NS
CHF: Oedema d/t salt & water retention (HypoNa) Avoid Na rich fluids like RL & NS, Don’t chase urine output
ARDS: Pulmonary edema d/t inc capillary permeability, Keep dry, maintain balance b/w diuretics and fluid to keep MAP >75-80mmHg
In Neurological ds: maintain euvolemia (no hypotension) caution during mannitol, avoid hypotonic fluids and hyperglycemia (avoid D5), RL appropriate for small vol infusion, NS is ideal
DKA: Glycosuria, osmotic diuresis, meta acid, K+ def, Mg & P def.

36. Preferred fluid therapy cont…
DKA cont…: Initial therapy NS, If no hypotension and good urine output RL can be given, KCL can be added here, Further can switch to 0.45 Saline (acc to Na conc), once sugars below 250mg/dl D5 is to be used.
In Renal Disease: Fluid restriction (Urine output + 500ml), in edematous pt so not chase the urine, salt restriction 2-3g/d, Avoid hyperkalemia (RL).
In nephrotic NS prefered
Pre-renal ARF: NS prefered
In CRF: 5D or 10D prefered, limit fluid admn

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