Fluid Therapy for the Bovine Patient Brad Jones DVM, MS GPVEC and PPVM UNL Objectives: • Understand the basic considerations of fluid administration as it relates to route, type and amount administered. • Understand differences in fluid administration for both the neonate and the adult bovine. • Establish a minimum data base for development of an appropriate fluid treatment plan for the bovine neonate. • Formulate a treatment plan as it relates to fluid administration for a calf presenting with neonatal diarrhea; addressing four core concepts of shock/dehydration, acidosis, potassium status, energy and prognosis (FPT). • Provide basic conversions to accomplish “fluid compounding” for practical use and fulfillment of the rotation quiz. Fluid Administration: Route • Fluid administration occurs via enteral and parenteral routes. – Enteral routes should be used in adult cattle when possible based on management and cost of IV administration. – IV administration • Complete replacement is more practical in neonates. • Hypertonic solutions can augment enteral routes Fluid Administration: Type • Composition of fluid to be administered depend on: – Route – Electrolyte status – Acid/Base status • Considerations include: – Water/Isotonic/hypertonic – Milk versus electrolytes – Alkalizing? Type? Fluid Administration: Amount • Basic concepts of fluid correction are centered around these three basic parameters in all species: – Maintenance • cow versus calf – Dehydration – Ongoing loss. • Rate of administration based on the size of the animal can be quite rapid but should not exceed 80mls/Kg in the first hour or 30mls/Kg chronically in calves. Cows should not exceed 40mls/kg/Hr. Neonate or Adult? • Several differences are noted between the neonate and the adult with regard to fluid administration. – Size as it relates to practicality an cost of administration – Acid base status – Status of gastrointestinal tract • Calves versus cow • Functional? Fluid administration: Neonate • Five core concepts: – Treatment: • • • • Dehydration/Shock Hyper/Hypokalemia Energy Acidosis: BD or SID – Prognosis • FPT • Physical exam • Response to initial treatment Dehydration • Calculated based on – Eye positon – Skin turgor – Volume = % dehydration x BW Kg • Treatment is generally a combination of enteral and parenteral administration. – Oral fluids • Milk and electrolytes – IV fluids • Isotonic crystalloids • Hypertonic crystalloids Compiled from Howard, Smith, Blood et. al. Potassium • Acidosis may yield marked hyperkalemia • Total body stores depleted – Diarrhea – Renal excretion due to hyponatremia – Anorexia • Rapid administration can be lethal! • The sick dehydrated adult cow generally will benefit from potassium supplementation. Temperature • In my hands calves with diarrhea are rarely exhibit pyrexia; either normothermic or hypothermic. – Hypothermic? • Hypoglycemia • Endotoxemia – General indication for Dextrose administration • 2.5% to 5% solution • Other benefits? • Give to all? Acidosis • Two concepts and both appear effective in treatment. – SID – H-H: Acidosis as measured by CO2 or bicarbonate to determine base deficit • mEqNaHCO3 Needed = (BW kg) ( 30 – TCO2) (.6) – – *30-TCO2 is the Base Deficit 0.6 is the coefficient of extracellular fluid in calves • Numerous ways to correct – Isotonic sodium bicarbonate – Hypertonic sodium bicarbonate – Crystalloids with added hypertonic sodium bicarbonate Assessment of Acidosis • Two common ways to assess base deficit; – TCO2 – Demeanor score Base Deficit (Meq) Demeanor Score (< 8 days of age) Base Deficit (Meq) Demeanor Score (> 8 days of age) Standing, good suckle 1 0 Standing, good suckle 1 5 Standing, weak suckle 2 5 Standing, weak suckle 2 10 Sternal recumbency 3 10 Sternal recumbency 3 15 Lateral recumbency 4 10 Lateral recumbency 4 20 Naylor Abaxis iSTAT 1 Fluid Replacement Considerations • Type? – Crystalloids • Hypertonic or isotonic? • Source? – Commercial or compounded? • Amount? – Dehydration, Maintenance, ongoing loss • Acidosis? – Assessment via demeanor score, TCO2 • Potassium? – Serum versus total body • Dextrose? – Temperature; Mentation and suckle reflex probably the result or acidosis. Word on Prognosis • For the neonate assessment geared to: 1. 2. 3. 4. 5. Definitive problem list; “diarrhea or not” Concurrent conditions to diarrhea. Passive Transfer Status Energy Status Severity of acidosis Fluid Therapy in Adults Differences from the neonate? 1. Conditions that require administration are different. 2. Tend to suffer from alkalosis thus require acidifying solutions. 3. As discussed amount of fluid is significant. 4. Ruminant digestive system. Clinical presentation in the adult? 1. Most likely dehydration not overt shock. 2. Negative base excess. – – Mature cattle twice as likely to be alkalotic. Exceptions rumen acidosis, pneumonia and diarrhea. 3. Very often hypochloremic, hypokalemic (at least total body stores) and need to consider hypocalcemia. Fluid Considerations: Type • Oral solutions – Water – Isotonic solutions • IV solutions – Crystalloids • Isotonic (generally NaCl with additional KCl) • Hypertonic NaCl – Calcium containing solutions • Acidosis corrected in similar fashion with the exception: conversion factor of extracellular volume is 0.3. meq Bicarb=BW (kg) x 30 – TCO2 (.3) Fluid Considerations: Amount • Maintenance fluids – Remember lactation but sick cows usually not an issue. • Ongoing losses – Often less of an issue than in the neonate. • Dehydration Constable PD. JAVMA 1998: 212:991-996 % Dehydration 0 2 4 6 8 10 12 14 Eyeball Recession (mm) 0 1 2 3 4 6 7 8 Skin-Tent Duration (s) 2 3 4 5 6 7 8 10 Fluid Considerations: Route • IV fluids – Crystalloids • Usually NaCl with added KCl – Hypertonic saline • Dose is 4-5 mls/kg BW (23/# BW) over 5 minutes. • Concurrent oral fluids, water and/or additional electrolytes should be administered. • Oral Fluids – Abomasal atony and pH not an issue versus calves – “cut off” for oral fluids alone: 8% dehydration • Not a hard rule and based on clinical evaluation. Administration Rate • Limit to 40ml/Kg/hour to adult cattle with normal cardiovascular function. – One 14 gauge catheter 20ml/kg/hour in a 500Kg cow. – Potassium added at rate of 25 mEq/liter will not excede 0.5mEq/Kg/hr – Can add 500ml of 23% calcium borogluconate per 20 liters Fluid Compounding • Conversions: – % solution to mg/ml? Move decimal place one to the right. – % solution to gram/100ml is as read. • Bicarbonate conversion: – 8.4% = 1 mEq/ml – 5% = 0.6 mEq/ml – 1.3% (isotonic) = 0.15 mEq/ml Resources for this presentation: • • • • • • • • • • Fluid Therapy in Calves. Smith, Berchtold. Vet Clin Food Anim 30 (2014) 409-427. Constable PD. JAVMA 1998: 212:991-996 Fluid Therapy in Mature Cattle. Roussel. Vet Clin Food Anim 30 (2014) 429-439. Hypokalemia Syndrome in Cattle. Sattler, Fecteau. Vet Clin Food Anim 30 (2014) 351-357. D-Lactic Acidosis in Neonatal Ruminants. Lorenz, Gentile. Vet Clin Food Anim 30 (2014) 317-331. Acid Base Assessment. Constable. Vet Clin Food Anim 30 (2014) 295-316. Treatment of Calf Diarrhea: Oral Fluid Therapy. Smith. Vet Clin Food Anim. 25:1 (2009) 55-72. Treatment of Calf Diarrhea: Intravenous fluid therapy. Berchtold. Vet Clin Food Anim. 25:1 (2009) 73-100. Veterinary Medicine a textbook of the diseases of cattle, sheep, pigs, goats and horses 9th ed. Radostits, Gay, Blood, Hinchcliff. Saunders 2000. Large Animal Internal Medicine 4th ed. Smith. Mosby 2009.