IV FLUIDS & ELECTROLYTES in SURGICAL PATIENTSIV Fluids: 60% of Total Body weight is Water Out of that 60%, 40% is ICF and 20% is ECF ICF is rich in Potassium. About 2l of ICF Fluid is a part of RBCs ECF is rich in Sodium. 11L are a part of ISF and 3L are a part of Plasma Vol. RBC+Plasma = Total Intra Vascular Volume (5L). An increase in ECF osmolarity is sensed by osmoreceptors in hypothalamus. This increases ADH release by the posterior pituitary. ADH increases the water permeability of late sections of the nephron The resulting fall in excretion of water helps restore ECF osmolarity.Plasma Volume Expansion (10 minutes after 250ml IV infusion):FluidPlasma Vol.ISF VolICF Vol

5%D18ml70ml162ml

RL/NS50ml200ml0ml

Colloids250ml0ml0ml

Albumin 25%1000ml--750ml0ml

7.5% Saline1750ml--500ml--1000ml

7.5% Saline (at equi)250ml1000ml--1000ml

Fluid losses occur as: Haemorrhage GIT Losses 3rd space losses Burns Pulmonary Losses Intraoperative Losses Polyuria Heat ExhaustionForces controlling Fluid movement in capillaries Starlings Law of Capillary Filtration: The role of hydrostatic and oncotic forces (starlings forces) in the movement of fluids across the capillary membrane.Q = k A [ (PcPif) + (if p) ]Q = Fluid Filtrationk = Capillary Filtration CoefficientA = Area of Capillary MembranePc = Capillary Pressure (hydrostatic pressure)Pif = Interstitial Fluid Pressure (hydrostatic Pressure) = Reflection Coefficient of Albuminif = Interstitial Fluid Colloid Osmotic Pressurep = Plasma Colloid Osmotic PressureApplication of Starlings Equation to fluids: Crystalloids increase capillary pressure more leakage in to ISF Interstitial edema Re-entry of fluids in to capillary space Colloids tend to retain capillary fluid maintenance of plasma volume Hypo-proteinemia ISF draws fluid from plasma edema

CRYSTALLOIDS:Crystallos : Clear Ice Eidos : AppearanceCommonly Used: 5% Dextrose, Ringers Lactate, Normal Saline, Dextrose Normal SalineInfrequently Used: 10% Dextrose, Darrows Solution (lactated pot. Saline), Hypertonic Saline5% Dextrose:Indications: As a Life line Replacement of Water loss Part of Postoperative Fluid Therapy In GIK Infusion Therapy As a Medium to deliver Drugs e.g. Dopamine, Deriphyllin, InsulinContra-indications: Head Injuries Diabetic Coma Hyponatremia/Hypokalemia Anasarca Pulmonary Oedema Renal Failure

FLUIDGLNa+ K+Ca++Cl-HCO3-OsmCalpH

5%Dex5Gm -- -- -- -- -- 278 20 07

R L --131 05 02 111 29 274 -- 6.3

N S --154 -- --154 -- 308 -- 07

DNS5Gm154 -- --154 -- 585 20 07

Properties of Crystalloids:

Ringer lactate:Indications: Hemorrhagic Shock Hypovolemia due to GIT Losses Hypotension Burns Postoperative Fluid Therapy As a Preloading Fluid As a Hemodiluent in Acute Normovolemic HaemodilutionContra-indications: Hepatic Failure Metabolic Acidosis Hypertension Hyperkalemia Head Injuries

Normal Saline:Indications: GIT Losses Head Injuries Post operative fluid Therapy Maintenance Fluid in NIDDM Hyponatremia Water Intoxication Gastric/Peritoneal LavageContra-indications: Hypernatremia, Hypertension Renal failure, AnasarcaAdvantages of Crystalloids: Less Expensive Easy Availability Greater Urinary Flow Replace Sequestrated Fluids Low Incidence of Allergic Reactions Can Be Given Rapidly No Interference with Grouping & Cross matching No CoagulopathyDisadvantages of Crystalloids: Fluid Reactions Water Intoxication Dyselectrolytemia Pulmonary Oedema Re-entry from 3rd Space Increased Cardiac Workload Dilutional Anaemia CoagulopathyColloids:Kolia : Glue Eidos: AppearanceCommonly Used Colloids: Hemaccel, Hes- steril 3%,6%,10%, Blood, MannitolInfrequently Used Colloids: Plasma, Albumin 5%,25%, Expan, Lomodex 40,60Haemaccel:Indications: Hemorrhagic Shock Post-spinal Hypotension Anaphylactic Shock Hemodiluent in ANH Surgical Patients with MS/ASContra-indications: Patients with Atopy Bronchial Asthma Septicemia Pulmonary oedema/ARDS Hypertension Patients with unknown Blood Gp Bleeding DiathesisHydroxy Ethyl Starches: Another form of hypertonic synthetic colloids used for volume expansion Contain sodium and chloride and used for hemodynamic volume replacement following major surgery and to treat major burns Less expensive than albumin and their effects can last 24 to 36 hours Less Incidences of immune reactions compared to Hemaccel.

Advantages of Colloids: Smaller Infused Volumes Prolonged Increase in PV Minimal Oedema (Peripheral/Cerebral) Higher DO2 (Systemic Oxygen Delivery) Useful in Preloading before Sub Arachnoid Block Useful in Hemodilution Fewer DyselectrolytemiasDisadvantages of Colloids: Greater Expense Coagulopathy (Dextran>HES) Interferes in Grouping & Cross matching Pulmonary Oedema (Septicemia & ARDS) Decreased GFR Osmotic Diuresis, Hypocalcemia (with Albumin)Body Fluid Requirements at Rest:1. Measurable Losses(Renal + GIT + Drains) + 9OOml2. 20 to 40 ml/kg/day3. 1000 ml to1500 ml/M2/Day4. 01 to 10kg BW=04 ml/kg/hr +10 to 20kg BW=02 ml/kg/hr + For remg BW=01 ml/kg/hrFluid Resuscitation: Correction of existing abnormalities in volume status or serum electrolytes (asin hypovolemic shock) - Parameters used to assess volume deficit?1. Blood pressure2. Urine output3. Jugular venous pressure4. Urine sodium concentrationHow to know that the patient has Hypovolemic Shock? Anxiety, Agitation Cool Pale Skin, Confusion Decreased or no urine Output Rapid breathing Disoriented, Loss Of Consciousness Low BP, Cold Extremities Rapid, Thready PulseRate of fluid repletion:1- Severe volume depletion or hypovolemic shock: Rapid infusion of 1-2L of isotonic saline (0.9% NS) as rapidly as possible to restore tissue perfusion2- Mild to moderate hypovolemia:Choose a rate that is 50-100mL/h greater than estimated fluid losses. calculating fluid loss as follows: Urine output= 50ml/h Insensible losses = 30ml/h Additional loss such as Vomiting or Diarrhoea or high fever (additional 100- 150 ml/day for each degree of temp >37 C)Signs and symptoms of Fluid overload:They are not always typical but most commonly are:1- Edema (swelling) - particularly feet, and ankles2- Difficulty breathing while lying down3- Crackles on auscultation4- High blood pressure5- Irritated cough6- Jugular vein distension7- Shortness of breath (dyspnea)8- Strong, rapid pulse

Management: Prevention is the best way Sodium restriction Fluid restriction Diuretics Dialysis How to Calculate IV Flow Rate:What is a drop factor?Drop factor is the number of drops in one milliliter used in IV fluid administration (also called drip factor). A number of different drop factors are available but the Commonest are:1- 10 drops/ml (blood set) 2- 15 drops / ml (regular set)3- 60 drops / ml (microdrop, burette)volume (ml) X drop factor (drops / ml) ---------------------------------------------time (min)= drops / min(flow rate)

Recent advancements: Interosseous Route tibia, femur, Superior iliac crest, head of the humerus Auto-transfusion Techniques Artificial Haemoglobins Perfluoro Carbon based and Haemoglobin based Hypertonic Salines Salt-free Albumins Tetrastarches (Voluven)

Electrolytes:Hyponatraemia: Def : Vomitings Hypoventilation -> Respiratory Failure Atrial / Ventricular Tachycardia -> Arrest Rhabdomyolysis in Chronic CasesECG Changes: Prolonged PR Interval Depression of ST Segment T Wave Flattening -> Inversion Prominent U Waves Apparent Prolongation Of QT Interval Hypokalemia Potentiates Digitalis ActionTreatment: Potassium Supplementation Oral: Food, Potchlor, Delayed Release Formulations IV: KCL, Acetate, Citrate, Gluconate, Bicarbonate, Phosphate Rate Of Correction not > 10 mEq/L per Hr Ensure Renal Function ECG Monitoring Bolus Effect on Heart Stop Loop Diuretics Use Potassium Sparing DiureticsHyperkalemia:Def: > 5.0 mEq/LCauses: Pseudohyperkalemia Excessive Intake (Exogenous): Oral, IV, Blood Transfusion, GI Bleeding, TPN, K Penicillin Excessive Release (Endogenous): Tissue Damage, Tumour Lysis, Burns, Rhabdomyolysis, Haemolysis, Septicemia Decreased Renal Excretion: Drugs, RF Compartment shift: Acidosis, Insulin Defi, Digoxin Over Dosage, Scoline, B BlockersManagement: Treat if K > 6.5 mEq/L Membrane Stabilization: 1 or 2 amp of CaCl2 IV Stat (onset in sec, lasts 30 mins) Shift Of Potassium into Cells: IV Insulin + Glucose (onset 2 or 3 mins, lasts few Hrs) Asthalin Nebulization IV Sodium Bicarbonate 2 amp Stat Removal of Potassium: Loop Diuretics GI Potassium Binding Resin: Kayexalate 30gmsPO or 50gms PR Acute Hemodialysis: In Life Threatening HyperkalemiaHypocalcaemia:Def: Serum Ca++ < 8 mg%Causes:- GIT: Acute Pancreatitis, Pancreatic / Enteric Fistulae Renal: Acute / Chronic RF Endocrinal:Hypo PTH, Excision of PTH, Hypothyroidism Necrotizing Fasciitis Severe Alkalosis, Hypo Magnesenemia Rapid Blood TransfusionSymptoms: Petechiae, Parasthesias Hyperreflexia, Carpopedal Spasm, Chvosteks Sign Muscle / Abdominal Cramps ECG: Prolongation of QT Interval Life threatening: Laryngospasm, cardiac arrhythmiasManagement: Correction of Underlying Cause Correction of Deficit: Acute: Inj CaCl2 / Ca Gluconate IV Chronic: Calcium Lactate, Milk Orally During Massive Blood Transfusion: 02 ml of 10% CaCl2 IV per Every 500 ml of blood Through a Separate Line Monitor Serum Ca++ Levels: Watch for Hypocalcemia and nephrolithiasis after long term calcium therapy. Monitor QT IntervalsHypercalcaemia: Def: Serum Ca++ > 11 mg % Causes: Pseudohypercalcemia PTH Mediated: Hyperparathyroidism, Ca Parathyroid Gland -> 45%PTH Nonmediated: Other Malignancies, MEN Type I & II Vitamin A & D Intoxication, Milk-Alkali Syndrome, Ortho: Pagets Disease, Rheumatoid Arthritis Renal: Renal Transplant, Diuretic phase of RF Granulomatous Diseases: TB, SarcoidosisClinical Features: Asymptomatic GIT: Anorexia, Nausea, Constipation CNS: Irritability, Weakness, Fatigue, Photophobia, Stupor, Coma Renal: Nephrocalcinosis, Nephrolithiasis ECG: Prolonged PR Interval, Shortened QT Management: Calciuretic Diuresis -> Saline + Lasix Inj Calcitonin 4 to 8 IU / Kg sc q 6-12 Hrs Diphosphonates: Didronel 7.5 mg / Kg Gallium Nitrate 100200 mg/M2 BSA/24 Hrs IV Phosphate, IV EDTA, Haemodialysis