INTRAVENOUS Fluids Presented By Muhammad Suleman Raza

The goal of intravenous fluid administration is to carefully achieve and maintain a euvolemic and isotonic environment within the body as well as to provide for a variety of nutritional and pharmacologic interventions. The selections of an appropriate IV solution is dependent upon the fluid volume and electrolyte status of the individual patient.

Na concentration in Body fluids Body FluidConcentration serum mEq/L Saliva10-55mEq/L Gastric juice10-100mEq/L Pancreatic juice mEq/L Bile mEq/L Intestinal mEq/L Stool/diarrhea1-100mEq/L Skin1-80mEq/L

Na distribution in Body Compartment or TissueNa Distribution Plasma11% Interstitial29% Connective Tissues12% Bone Exchangeable Non-Exchangeable 14% 29% Intracellular2.5% Transcellular2.5% Total100%

Water distribution in body

Cont….

General Recommendations For IV Fluid Selection Hyponatremia with Hypovolemia  Decreased total body water and Na,Relatively greater decrease in Na  External losses  GI : vomiting,Diarrhea, fistulas,ostomies  Third-space loses : Pancreatitis, peritonitis,small-bowel obstructions, Rhabdomyolysis, Burns, Post operative period.  Renal loses:  Diuretics.  Osmotic diuresis.  Mineralocorticoid deficiency.  Salt- losing Naphropathies.

Cont… Hypernatremia with Hypovolemia  Decreased TBW and Na ; relatively greater decrease in TBW.  External losses.  GI: vomiting,Diarrhea.  Skin : Burns, excessive sweating.  Renal losses.  Diuretics medications.  Osmotic Diuresis.

Cont… Hypernatremia with Euvolemia  Relatively decreased TBW ; increased Total body Na.  Inability to access free water.  Patients on tube feeding.  Can’t reach water glass.  NPO on isotonic IV fluids only.

Cont…. Hypernatremia with hypervolemia Increased TBW; greater increase in Na.  Hypertonic IV fluid administration without free water.  Total parental nutrition with inadequate free water.  Mineralocorticoid excess.

Type of IV solution IsotonicHypotonicHypertonic

Isotonic solution  A solution that has the same salt concentration as the normal cells of the body and the blood.  Ex: % NaCl. 2- Ringer Lactate. 4- D5W.

Hypotonic solution A solution with a lower salts concentration than in normal cells of the body and the blood.  EX: % NaCl % NaCl.

Hypertonic solution: A solution with a higher salts concentration than in normal cells of the body and the blood.  Ex: D5W in normal Saline solution. D10W.

Categories of intravenous solutions according to their purpose: Nutrient solutions. Electrolyte solutions. Volume expanders.

Nutrient solutions. It contain some form of carbohydrate and water. Water is supplied for fluid requirements and carbohydrate for calories and energy. They are useful in preventing dehydration and ketosis but do not provide sufficient calories to promote wound healing, weight gain, or normal growth of children. Common nutrient solutions are D5W and dextrose in half-strength saline.

Electrolyte solutions (Crystalloid) fluids that consist of water and dissolved crystals, such as salts and sugar. Used as maintenance fluids to correct body fluids and electrolyte deficit. Commonly used solutions are: -Normal saline (0.9% sodium chloride solution). -Ringer’s solutions (which contain sodium, chloride, potassium, and calcium. -Lactated Ringer’s solutions (which contain sodium, chloride, potassium,calcium and lactate).

Volume expanders (Colloid)  Are used to increase the blood volume following severe loss of blood (haemorrhage) or loss of plasma ( severe burns).  Expanders present in dextran, plasma, and albumin.

Parenteral Nutrition (PN)  Parenteral nutrition is a form of nutritional support that supplies protein, carbohydrate, fat, electrolytes, vitamins, minerals, and fluids via the IV route to meet the metabolic functioning of the body.

IV Infusion Method I.V. Bolus (I.V. push) Continuous- drip infusion Intermittent infusion

FluidNaKGlucoseTonicityMosm/liter 0.9 NS*15400Slightly Hypertonic NS*7700Hypotonic NS*3800Hypotonic77 Lactated Ringers (LR) 13040Isotonic280 D5W0050gmHypotonic0** D5W 0.45 NS* 77050gmHypotonic154** 0.9 NS+150 mEq NaHCO Very Hypertonic 616 Electrolyte content of IV solutions per Liter

Hypertonic SolutionsContent (mEq/L)Clinical Implication Dextrose 5% in 0.45% NS*77 Na,77 ClDaily maintenance of body fluid and nutrition. Dextrose 5% in 0.9% NS*154 Na, 154 ClFluid replacement of Na,Cl and calories (170) Dextrose 10% in 0.9% NS*154 Na, 154 ClFluid replacement of Na,Cl and calories (340) Dextrose 5% in Lactated Ringer 130 Na,4 K,109 Cl, 28 lactate, 3Ca2+ Resembles the normal composition of Blood, serum and plasma K+ level below bodies daily requirement caloric value (180)

General Recommendations For IV Fluid Selection Achieving Euvolemia Achieving Isotonicity Determine the pt. volume status estimate if any,the degree of variation from euvolemia If euvolemic,only maintenance fluids need to be prescribed, as in pt. who may be NPO. Volume replacement because of additional clinical volume loss like NG suction, diarrhea, Blood loss Measure I/O VOLUME BODY WEIGHT AND Na content of specific fluid loss Tonicity of body fluids can be measured directly (serum osmolality), or estimated approximately from the serum sodium concentration ([Na]x2 +10) or more exactly from the formula [Na]x2+glucose/18 The isotonic pt. requires only maintenance Na replacement unless they are also dehydrated The hypertonic (Hypernatremic) pt. requires additional free water replacement. Average TBW=0.66 X body weight. Water Deficit=TBW x[serum Na – 140]/140 The hypertonic (Hypernatremic) pt. requires additional free water replacement. Average TBW=0.66 X body weight. Water Deficit=TBW x[serum Na – 140]/140 The dehydrated pt. will require an estimated amount of isotonic fluid to bring them to normal volume status

Conclusions  Achievement and maintenance of a euvolemic and isotonic internal environment requires careful adjustment of water and Na intake that reflects the excesses or deficits of these physiologically linked nutrients.  Optimal care of fluid status of an individual also requires an appreciation of the limits of Na and water handling which can vary from pt. to pt depending upon such factors as Age, Renal and Cardiac function and variations in their otherwise routine intake of Na.  Standard assessment method include physical examination, serum Electrolytes, and accurate body weight and fluid intake and output measurements.

References  Androgue HJ,Madias NE. Hyponatremia,NEJM,2000;342(21):  Simpson FO. Sodium intake, body sodium and sodium excretion.Lancet,1988;7(2):25.   -Carol.T.taylor and carol lillis.R, (2001): Fundamentals of Nursing, 4 th ed,Lippincott, company,Pheladelphia,pp: