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 = mOsm/kg The ICF and ECF are in osmotic equilibrium
OSMOLALITY OSMO LAL ITY = mOsm/kg of solvent OSMO LAR ITY = 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)
Who regulates osmolality?
WATER BALANCE Important in the regulation of osmolality Modification of water intake and exretion
60% ICF ECF TOTAL BODY WATER 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
WHAT IS THE BODYS 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 = meq/L FOR Na CORRECTION : Maintenance of 2-4 meq/kg/day
INTRAVENOUS FLUIDS chemically prepared solutions Achieve and maintain a euvolemic and isotonic environment within the body They are tailored to the bodys 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 = mOsm/L Na = meq/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 IV FLUIDOSMOLARIT Y (mosm/L) Na+ (mmol/L) K+Cl-Base PNSS ? PLR273130??? D5LR D5NR552140?9850 D50.3NaCl D5IMB D5NM D5W
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 BLOOD PRODUCTCOMPUTATION pRBC10 ml/kg to run for 4 hours Fresh whole blood10-20 ml/kg in 4-6 hours Platelet Concentrate ml/kg as fast drip Cryoprecipitate1 unit/6kg/dose
FLUID DEFICITS Ludans Method WEIGHTMILD DEHYDRATION ml/kg/8 hours MODERATE DEHYDRATION SEVERE DEHYDRATION <15 kg >15 kg 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 D5LR
FLUID DEFICITS – WHO *Use Ringers Lactate AGEFIRST GIVE 30ml/kg in: THEN GIVE 70ml/kg in: Infants under 12 months 1 hour5 hours Older30 minutes2 ½ hours SEVERE DEHYDRATION SOME DEHYDRATION 75ml/kg in 4 hours
SODIUM CORRECTION 1. DEFICIT CORRECTION : desired-actual x weight x 0.6 * Desired Na+ is meq 2. MAINTENANCE COMPUTATION : maintenance x weight *Maintenance is 2-4meq/kg 3. 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 1. COMPUTE FOR THE K+ REQUIREMENT = 2-4meq/kg/day 2. DETERMINE how much KCL you will be incorporating in your IV fluid to complete a 24 hour correction a) Check IV fluid rate b) *Maximum 40meq/Liter of KCL incorporation in IV Fluid 3. 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 WEIGHTWATER (ml/kg/day) First 10 kg 100 ml/kg Second 10 kg (<20kg) 50ml/kg for each kg > 10kg ml Each additional kg (>20kg) 20ml/kg for each kg > 20kg ml
MAINTENANCE REQUIREMENTS Ludan Method BODY WEIGHT (kg)TOTAL FLUID REQUIREMENT (TFR) at ml/kg/day > 3-10 kg 100ml/kg/day > kg 75ml/kg/day > 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
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 D5LR/ D5NSS/ D50.9NaCl Maintenance rate using Holliday Segar/Ludan Correct in 24 hours With MILD Dehydration 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 NELSONS 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