IV FLUIDS

Basic Principles

BASIC PRINCIPLES Osmolality/Osmolarity Tonicity Sodium & Water balance

What is Osmolality?

OSMOLALITY Measurement of concentration of particles in a solution (Total concentration of penetrating & nonpenetrating solutes) i.e. Concentration of electrolytes, drugs, glucose in a solution such as serum or urine

OSMOLALITY Normal = 285-295 mOsm/kg The ICF and ECF are in osmotic equilibrium

OSMOLALITY OSMOLALITY = mOsm/kg of solvent OSMOLARITY = mOsm/liter of a solution

What is Tonicity?

TONICITY measure of the ability of a solution to cause a change in the volume or tone of a cell by promoting osmotic flow of water (Total concentration of penetrating solutes only)

TONICITY

Who regulates osmolality?

Water

WATER BALANCE Important in the regulation of osmolality Modification of water intake and exretion

60% ICF TOTAL BODY WATER ECF Interstitial Fluid Plasma

FORCES THAT MOVE WATER Osmolality Tonicity Na/K ATPase pump Hydrostatic pressure Oncotic pressure

SODIUM BALANCE The main regulator of intravascular volume status

Electrolyte composition EXTRACELLULAR FLUID INTRACELLULAR FLUID

WHAT IS THE BODY’S GOAL? PHYSIOLOGIC HOMEOSTASIS EUVOLEMIA ISOTONIC ENVIRONMENT

What mechanisms in the body makes sure that the balance of sodium and water is normal? What hormones play a big role in the maintenance of physiologic homeostasis?

There are upper & lower limits to the amount needed to achieve ideal physiologic homeostasis

WATER REPLACEMENT 1.5 to 2 liters / day

SODIUM REQUIREMENT DIET: RDA = < 2400mg/day (1 teaspoon/day) or < 104 meq/day PLASMA : Normal levels = 135-145meq/L FOR Na CORRECTION: Maintenance of 2-4 meq/kg/day

Intravenous Fluids

INTRAVENOUS FLUIDS chemically prepared solutions Achieve and maintain a euvolemic and isotonic environment within the body They are tailored to the body’s needs and used to replace lost fluid and/or aid in the delivery of IV medications

ISOTONIC IV FLUIDS created to distribute evenly between the intravascular, interstitial, and cellular spaces.

HYPOTONIC IV FLUIDS What IV fluids are specifically designed so the fluid leaves the intravascular space and enters the interstitial and intracellular spaces?

HYPERTONIC IV FLUIDS What IV fluids are designed to stay in the intravascular space (intra, within; vascular, blood vessels) to increase the intravascular volume, or volume of circulating blood?

ISOTONIC SOLUTIONS = 285-295 mOsm/L Na = 135-145meq/L HYPERTONIC SOLUTIONS = > 300 mOsm/L Na = > 150meq/L HYPOTONIC SOLUTIONS = < 260 mOsm/L Na < 130meq/L

CRYSTALLOIDS contain electrolytes (e.g., sodium, potassium, calcium, chloride) but lack the large proteins and molecules found in colloids. classified according to their “tonicity.” describes the concentration of electrolytes (solutes) dissolved in the water, as compared with that of body plasma (fluid surrounding the cells).

COMPOSITION OF IV FLUIDS OSMOLARITY (mosm/L) Na+ (mmol/L) K+ Cl- Base PNSS 308 154 ? PLR 273 130 D5LR 525 4 109 28 D5NR 552 140 98 50 D50.3NaCl 355 51 D5IMB 350 25 20 22 23 D5NM 368 40 3 16 D5W 255

COLLOIDS contain solutes in the form of large proteins or other similarly sized molecules. Remain in the blood vessels for long periods of time and can significantly increase the intravascular volume (volume of blood).

COLLOIDS/PLASMA EXPANDERS Albumin = 1-2 kg/dose infused in 2 hours Haes-teryl = 20-40ml/kg Voluven = 20-40ml/kg Gelofuschin = 20-40ml/kg Fresh frozen plasma = 10-15ml/kg x 4 hours Dextran 40 or 60

BLOOD AND BLOOD PRODUCTS are the most desirable fluids for replacement but are not the first choice for immediate volume expansion in children with shock Not only is the intravascular volume increased, but the fluid administered can also transport oxygen to the cells.

BLOOD AND BLOOD PRODUCTS COMPUTATION pRBC 10 ml/kg to run for 4 hours Fresh whole blood 10-20 ml/kg in 4-6 hours Platelet Concentrate 15-20 ml/kg as fast drip Cryoprecipitate 1 unit/6kg/dose

Computation

OVERALL GOALS 1)ESTIMATE LOSSES Fluid & Electrolyte deficit Maintenance requirements Ongoing losses 2)SELECT IV FLUID Initial replacement – always with ISOTONIC FLUID Maintenance requirement & ongoing losses

STEP ONE: Estimate Losses SEVERITY OF DEHYDRATION INFANT (ml/kg) ADOLESCENT (ml/kg) CLINICAL SIGNS MILD 5% (50) 3% (30) Dry mucous membranes Oliguria MODERATE 10% (100) 6% (60) Poor skin turgor Sunken fontanel Marked oliguria Tachycardia Quiet tachypnea SEVERE 15% (150) 9% (90) Marked tachycardia Weak to absent distal pulses Narrow pulse pressure Hypotension and altered mental status

STEP TWO: In shock?

MACRODRIP SETS = 10 – 15 drops (gtts)/ml MICRODRIP SETS= 60 microdrops (ugtts)/ml)

(Volume in mL) x (drip set) gtts ------------------------------------ = ------ (Time in minutes)    min

CONVERSION FACTORS 1 ml = 15 drops (gtts) = 60 microdrops (ugtts) 1 drop (gtt) = 4 microdrops (ugtts) 1 microdrop (ugtts)/min = 1 ml/hour

FLUID DEFICITS Ludan’s Method WEIGHT MILD DEHYDRATION ml/kg/8 hours MODERATE DEHYDRATION SEVERE DEHYDRATION <15 kg 50 100 150 >15 kg 30 60 90 Give ¼ in 1 hr Give ¾ in 7 hr Give 1/3 in 1 hr Give 2/3 in 7hr PLAIN LR/PLAIN NSS D5LR PLAIN LR/ PLAIN NSS

FLUID DEFICITS – WHO *Use Ringer’s Lactate SOME DEHYDRATION 75ml/kg in 4 hours SEVERE DEHYDRATION AGE FIRST GIVE 30ml/kg in: THEN GIVE 70ml/kg in: Infants under 12 months 1 hour 5 hours Older 30 minutes 2 ½ hours

SODIUM CORRECTION DEFICIT CORRECTION: desired-actual x weight x 0.6 * Desired Na+ is 135-145 meq MAINTENANCE COMPUTATION: maintenance x weight *Maintenance is 2-4meq/kg COMPUTE FOR ACTUAL Na+ Needed to be incorporated in your IV FLUID = Maintence + Deficit *Give the First ½ in 8 hours then ¼ in each succeeding 8 hour shifts to complete your 24 hour correction

POTASSIUM CORRECTION COMPUTE FOR THE K+ REQUIREMENT = 2-4meq/kg/day DETERMINE how much KCL you will be incorporating in your IV fluid to complete a 24 hour correction Check IV fluid rate *Maximum 40meq/Liter of KCL incorporation in IV Fluid CHECK POTASSIUM INFUSION RATE (KIR) = meq of KCL x IV rate (ml/hour) x weight (maximum of 0.2meq/kg/hour)

MAINTENANCE REQUIREMENTS Holliday-Segar Method BODY WEIGHT WATER (ml/kg/day) First 10 kg 100 ml/kg Second 10 kg (<20kg) 50ml/kg for each kg > 10kg + 1000ml Each additional kg (>20kg) 20ml/kg for each kg > 20kg + 1500ml

MAINTENANCE REQUIREMENTS Ludan Method BODY WEIGHT (kg) TOTAL FLUID REQUIREMENT (TFR) at ml/kg/day > 3-10 kg 100ml/kg/day > 10-20 kg 75ml/kg/day > 20-30 kg 50-60ml/kg/day >30-60 kg 40-50ml/kg/day

IV FLUID SELECTION INITIAL REPLACEMENT (GOAL: Restore Intravascular volume & Tissue Perfusion)– always with an ISOTONIC SOLUTION PNSS , PLR, PNR FOLLOW UP HYDRATION (For Ongoing Losses) – Isotonic/Hypertonic, can be Glucose containing D5LR, D5NR MAINTENANCE – Usually Hypotonic D5IMB , D5NM

FLUIDS NOT WORKING? Review medications: Dopamine Dobutamine Norepinephrine Epinephrine Milrinone Vasopressin Nitroprusside

STEP THREE: Frequent Reassessment Pulse quality Heart Rate Capillary Refill Time Urine Output Temperature Blood Pressure Neurologic Function Oxygen saturation Breath sounds and respiratory rate

STEP FOUR: Ancillary studies & Pharmacologic interventions TREATMENT Shock etiology & severity Organ dysfunction Metabolic derangements Response to therapeutic interventions Medications Correct metabolic derangements Manage pain and anxiety Subspecialty consult

ADDITIONAL READING CASES HYPOVOLEMIC SHOCK DISTRIBUTIVE SHOCK OBSTRUCTIVE SHOCK CARDIOGENIC SHOCK NEUROGENIC SHOCK OTHERS Diarrhea Sepsis Pericardial tamponade Brain tumor Poisonings DKA Tension pneumothorax Brain trauma Nephrotic/Nephritic syndrome Burns Ductal dependent heart lesions Fluids for newborns Dengue Massive pulmonary embolism Anaphylactic shock Trauma Surgical cases

BURNS Parkland Formula Crystalloid at 4ml/kg x % BSA burned + Maintenance requirement Give ½ over the first 8 hours Then ½ over the next 16 hours *See Burn Assesment Chart for %BSA burned

DENGUE PPS 2010 Recommendations NOT in Shock With MILD Dehydration D5LR/ D5NSS/ D50.9NaCl Maintenance rate using Holliday Segar/Ludan Correct in 24 hours D5LR/ D5NSS/ D50.9NaCl Maintenance rate (Ludan) + Mild Dehydration (Ludan) Give ½ in the first 8 hours Give the rest in the remaining 16 hours

END NELSON’S TEXTBOOK OF PEDIATRICS HARRIET LANE PPS DENGUE 2010 GUIDELINES

CASE 1 year old MALE was brought to the ER by his hysterical mother due to sudden generalized tonic clonic convulsions and upward rolling of the eyeballs which occurred five minutes prior to consult. This is reported to be his first attack. On further investigation, you noted a 3 day history of vomiting followed by diarrhea. The vomiting occurs 2x/day, postprandial, amounting to ½ cup per episode.

The frequency of the diarrhea was 6-8 stools/day amounting to 1 cup/episode, watery, blood streaked; This was accompanied by fever (tmax 39) and intermittent episodes of abdominal pain; No known unusual food intake but the child plays with the neighborhood kids a lot and comes home very dirty. (+) decrease in appetite; Noted progressive decrease in activity

Last urine output noted 9 hours prior to consult; (+) Family history of BFC – paternal relatives The rest of the history was unremarkable

PHYSICAL EXAMINATION Temperature 39; Heart rate 140/ minute; Respiratory rate 42/min; Blood pressure 90/60 Asleep, arousable; Not in respiratory distress; Good skin turgor; Pink, dry lips, no tpc, dry oral mucosa, sunken eyeballs, no clad; Equal chest expansion, clear breath sounds, no retractions;

Heart with regular rhythm, no murmurs; Abdomen tympanitic, soft, hyperactive bowel sounds Full and equal pulses