Fluid Therapy: Practical and effective medical care on farm

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1 Fluid Therapy: Practical and effective medical care on farm Jim Brett, D.V.M. Associate Clinical Professor Large animal ambulatory service Mississippi State University

2 Fluid therapy If you only had to choose ONE drug to keep on your truck at all times it should be fluids. o Dr. Elaine Hunt (MSU-CVM 1982) Dehydration leads to decreases in plasma volume, extracellular fluid volume, cardiac output, and oxygen delivery, a condition generally referred to as hypovolemic shock. Dehydration does not appear to be the most important cause of death in calf diarrhea, but it is associated with acid-base and electrolyte disturbances. o Dr. Geoff Smith (NC State CVM)

3 Hydration problems It is not uncommon to find adult cattle dehydrated, especially in summer conditions with ANY disease or metabolic condition. Adult cows normally consume gal. of water daily. In summer months, consumption often increases ~ 50%. Metabolic problems (ketosis, hypocalcemia) and common systemic diseases (pneumonia, metritis, mastitis) often cause lower intakes & renal issues Other common problem: lack of or availability or linear space to drink; water quality

4 Sick calf: Is she acidotic or alkalotic? Metabolic acidosis - results primarily from intestinal bicarbonate loss with minor contributions from 1) lactic acid production in tissues secondary to hypoxia and 2) decreased acid secretion by poorly perfused kidneys. Recent studies: results from differences in strong ion balance with forestomach / intestinal fermentation of malabsorbed nutrients leading to increased serum concentrations of D-lactic acid

5 Sick calf: Is she acidotic or alkalotic? But.. Metabolic acidosis is not highly correlated with the degree of dehydration

6 Sick cow: Is she acidotic or alkalotic? Metabolic alkalosis: common in adult ruminants with GI disturbances Caused by: excessive hydrogen loss bicarb retention contraction alkalosis ECF volume reduced dt loss of fluids high in Na & Cl w/out the loss of bicarb (scours) H loss: sequestra of fluids (DA s, vagal indigestion) Systemic disease: impaired renal bicarb retention & excess loss of Cl & H Metabolic acidotic cows DIE (fast)!

7 Assessment of dehydration in calves % dehydration Demeanor Sunken eye Skin tenting < 6% Normal none none 6-8% Depressed 2-4 mm 1-3 sec 8-10% Depressed 4-6 mm 2-5 sec 10-12% Comatose 6-8 mm 5-10sec > 12% Dead 8-12 mm > 10sec All other methods of assessment are inferior to these two methods. The best laboratory test is change in plasma protein concentration (better than hematocrit).

8 Which IV fluids to use? Isotonic fluids: Lactated ringers (LRS): considered an alkalinizing fluid (that can increase blood ph). BUT - the lactate must be metabolized to produce an alkalinizing effect, this fluid type is considered a weak alkalinizer and is not recommended for neonates with severe acidosis (Do NOT use in adult bovine) Normal Saline (0.9%): non-alkalizing solution - acidifying; correct volume deficiency and helps correct extracellular fluid deficits

9 Which IV fluids to use? Isotonic Sodium Bicarbonate - This is the alkalinizing fluid of choice in calves with severe metabolic acidosis (ph <7.2) - more effective than other metabolizable bases (such as lactate), bicarbonate precursors, or synthetic bases Add 13 gram baking soda to 1 liter sterile water 48 cc of baking soda in a gallon of distilled water = ~1.3% isotonic solution. 5% Dextrose: used to counteract the negative energy balance in diarrheic calves with or without hypoglycemia. BUT in dehydrated calves a plain 5% dextrose solution is not sufficient to correct extracellular fluid deficits because the solution contains no sodium

10 How do you replace that much volume? Do the math (in your head): Adult holstein cow 1400 lb (~700 kg) o 8% dehydration: 700 X 0.08 = 56 liters Neonate calf 80 lb (~40 kg) o 8% dehydration: 40 X 0.08 = 3.2 liters Add Maintenance Needs: 40-60ml/kg (~1oz or 30ml/lb) 1400lb cow: liters 80lb calf: liters Liter ~ Quart 4QTS = 1 Gal.

11 How do you replace that much volume? So how do you get liters (~21to 25 gal) of fluids in the adult cow or (1 ¼ to 1 ½ gal) in the calf? (Real World) Conventional IV line: o Rate of admin: 1ml/lb/hr (C. Navarre LSU) 1400lb cow: ~1.5L/hr (takes hrs) o BUT, bovine can handle faster rates than other species (but be careful in calves) o Limiting factor is often the size of IV catheter o 20L carboy w/ 14 g cath takes 4 hrs Who had hours to monitor in the real world? Will the client pay for that time?

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14 High volumes: fast, safe & effective And the answer is. HYPERTONIC SOLUTIONS 2 Solutions commonly used: o Hypertonic saline (7.2% NaCl) o 8.4% Sodium bicarb Dose: o Hypertonic NaCl: 4-5ml/kg (~2ml/lb) o Hypertonic Bicarb: 5ml/kg (~2ml/lb) Rate: o Research give over ~ 4-5 minutes o Practice how fast could I get it thru a g butterfly cath to a calf or thru a 14 g needle and a simplex line in a cow?

15 Hypertonic Saline Hypertonic Saline - rapidly expands the plasma volume in a severely dehydrated calf. When combined with oral electrolyte solutions, this therapy is as effective in resuscitating severely dehydrated animal as large volume 0.9% NaCl administration and is less expensive and much easier to administer. Hypertonic saline does not correct metabolic acidosis. Hypertonic saline - indicated for the treatment of hyperkalemia in calves. Effective in rapidly decreasing serum K concentrations and reversing electrocardiographic abnormalities associated with hyperkalemia.

16 Hypertonic Bicarb / Dextrose Hypertonic sodium bicarbonate combined with oral electrolytes - corrects metabolic acidosis & dehydration in neonatal ruminants with diarrhea Dextrose - non-alkalinizing fluid 5% to 10% dextrose are sometimes used to counteract the negative energy balance in diarrheic calves with or without hypoglycemia. Does NOT correct extracellular fluid deficits because the solution contains no sodium. Energy source - add 50 to 100 ml of 50% dextrose solution can be added per liter of LRS or isotonic sodium bicarbonate to make a mildly hypertonic solution.

17 Results Blood ph Koch and Kaske, J Vet Int Med 2008; 22:

18 What next? You gave your hypertonic solution did you correct the hypovolemia? NO How do you get the fluid volume there: The answer is. o ORAL FLUIDS Why? o Generally safe (calf: if can suckle or chew, safe to give oral fluids) o Give high volumes rapidly o Increase osmotic value of blood causes its rapid absorption o Electrolytes can easily and cheaply added and administered

19 Oral products: Calves Sodium - the principal determinant of the volume of the extracellular space - must be present in an oral electrolyte solution to rapidly correct the losses that have occurred with dehydration and diarrhea. The ideal sodium concentration is mm/l. Amino acids - Neutral amino acids such as glycine, alanine or glutamine are necessary to facilitate sodium absorption and provide energy. Most oral electrolyte solutions contain either glycine or glutamine and experimentally there doesn t appear to be any difference between the two.

20 Oral products: Calves Alkalinizing agent - Acetate, propionate, and bicarbonate are all considered alkalinizing agents and are frequently present in commercial oral electrolyte solutions. Bicarbonate-containing products (i.e. Biolyte, Enterolyte HE ) are very effective at correcting a severe metabolic acidosis, since bicarbonate reacts directly with H+ ions to form CO2 and H2O. BUT: Acetate & propionate however are also alkalinizing agents, and are preferred over bicarbonate

21 Buffers Acetate and propionate stimulate sodium and water absorption in the calf small intestine (bicarbonate does not) Acetate and propionate do not alkalinize the abomasums (bicarbonate does) low abomasal ph is a natural defense mechanism against bacterial proliferation & is needed for digestion & milk ball formation. Acetate and propionate inhibit the growth of Salmonella species Acetate and propionate produce energy when metabolized (bicarbonate does not).

22 Calf oral electrolyte products The ideal oral electrolyte solution should have: Sodium concentration between 90 and 130 mm/l Potassium concentration of 25mM/L Chloride concentration between 40 and 90 mm/l 40 to 80 mm/l of a metabolizable (nonbicarbonate) base (Acetate or propionate) Glucose as an energy source. Unfortunately, most commercial products do not satisfy these ideals

23 Commercial products Resorb: 80 mm/l Sodium, Glycine for AA, 315 mosm/l, no alkalizing agent Vitalyte: 184 mm/l Sodium, Glycine for AA, 557 mosm/l, 110 mm/l bicarb Calf quencher: 142 mm/l Sodium, no AA, 731 mosm/l, 86 mm/bicarb Enterolyte: 105 mm/l Sodium, Glycine for AA, 739 mosm/l, 80 mm/l bicarb Diaque: 90 mm/l Sodium, Glycine for AA, 377 mosm/l, 25 mm/l bicarb Hydralyte: 90 mm/l Sodium, Glycine for AA, 614 mosm/l, 60 mm/l acetate Epic: 92 mm/l Sodium, Glycine for AA, 360 mosm/l, 52 mm/l acetate

24 Oral fluids adult bovine Cow products: Simpler: NaCl based - mix to provide isotonic solutions PO (hypotonic is also OK) Commercial products: Many available Homemade products (good and cheaper): o NaCl (salt)- 140 grams o KCl- 25 grams o CaCl 2-10 grams o Add to 5 gal oral fluids o Dr. Doug Hostetler s electrolyte powder: o 1/4 cup of NaCl +1 heaping Tblsp KCl o Add to 3-5 gal oral fluids with 200ml of Calcium Drench (liquid calcium product)

25 Other formulas Earl Aalseth, PhD DVM o 0.6 lb. calcium chloride or1 pound of calcium propionate, 1/2 pound of Epsom salt, 1/4 pound of KCL, 1/8 pound of regular salt, 12 oz of propylene glycol lb of dissolved rabbit pellets - put into gallons of warm water.

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27 Basic Equipment

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33 Questions, comments, concerns?