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  1. 1. Compendium CompendiumVet.com | Peer Reviewed | Listed in MEDLINE Vol 31(1) January 2009 9 CE Contact Hours CONTI N U I NG EDUCATION FOR VETERI NARIANS ® FREE CE Fever of Unknown Origin Diagnostic Approaches NEW Focus on Nutrition W I Improving Adherence i Ad to Recommendations Understanding Behavior: Patient Assessment IT n! N m IO lu Co 22 R O ion ge T Pa NU S trit CU Nu Se N FO New e
  2. 2. TREATMENT EAT NT ATME AID FOR AID FOR FeLV / FIV eLV FIV L F INFECTIONS FECTIONS N LTCI LYMPHOCYTE T-CELL IMMUNOMODULATO R NOMODUL ATOR Approved Treatment Aid for:: f or FeLV and/or FIV infections ections ti Including Associated Symptoms of: Oppor tunistic infection ction Lymphopenia Anemia Granulocytopenia Thrombocytopenia www.ProLabsAnimalhealth.com. 800-367-6359 LTCI has received a conditional license by the USDA; additional potency and efficacy studies are in progress. LTCI is manufactured by T-Cyte Therapeutics, Inc. and distributed by IMULAN BioTherapeutics and ProLabs Animal Health
  3. 3. January 2009 Vol 31(1) CompendiumVet.com | Peer Reviewed | Listed in MEDLINE EXECUTIVE EDITOR Tracey Giannouris, MA 800-426-9119, ext 52447 | tgiannouris@vetlearn.com MANAGING EDITOR Kirk McKay 800-426-9119, ext 52434 | kmckay@vetlearn.com Subscription inquiries: PUBLISHED BY 800-426-9119, option 2. SENIOR EDITOR Subscription rate: $79 for 1 Robin A. Henry year; $143 for 2 years; $217 800-426-9119, ext 52412 | rhenry@vetlearn.com for 3 years. Canadian and Mexican subscriptions (sur- ASSOCIATE EDITOR face mail): $95 for 1 year; Chris Reilly $169 for 2 years; $270 for 3 800-426-9119, ext 52483 | creilly@vetlearn.com years. Foreign subscriptions (surface mail): $175 for 1 EDITORIAL ASSISTANT Published monthly by Veteri- year; $275 for 2 years; $425 Benjamin Hollis nary Learning Systems, a for 3 years. Payments by division of MediMedia, 800-426-9119, ext 52489 | bhollis@vetlearn.com check must be in U.S. funds 780 Township Line Road, drawn on a U.S. branch of a Yardley, PA 19067. Copyright VETERINARY ADVISER U.S. bank only; credit cards © 2009 Veterinary Learning Dorothy Normile, VMD, Chief Medical Officer Systems. All rights reserved. are also accepted. Change 800-426-9119, ext 52442 | dnormile@vetlearn.com Printed in the USA. No part of of Address: Please notify the Circulation Department this issue may be reproduced SENIOR ART DIRECTOR in any form by any means 45 days before the change Michelle Taylor without prior written permis- is to be effective. Send your new address and enclose an 267-685-2474 | mtaylor@vetlearn.com sion of the publisher. address label from a recent issue. Selected back issues ART DIRECTOR Printed on acid-free paper, are available for $15 (United David Beagin effective with volume 29, States and Canada) and $17 267-685-2461 | dbeagin@vetlearn.com issue 5, 2007. (foreign) each (plus postage). PRODUCTION Periodicals postage paid at Indexing: Compendium: Con- Marissa DiCindio, Senior Production Manager Morrisville, PA, and at addi- tinuing Education for Veteri- 267-685-2405 | mdicindio@vetlearn.com tional mailing offices. narians® is included in the international indexing cover- Elizabeth Ward, Associate Production Manager–Journals Postmaster: Send address age of Current Contents/ changes to Compendium: 267-685-2458 | eward@vetlearn.com Agriculture, Biology and Continuing Education for Environmental Sciences (ISI); SALES & MARKETING Veterinarians®, 780 Township SciSearch (ISI); Research Line Road, Yardley, PA 19067. Joanne Carson, National Account Manager Alert (ISI); Focus On: Veteri- Canada Post international 267-685-2410 | Cell 609-238-6147 | jcarson@vetlearn.com publications mail product nary Science and Medicine (ISI); Index Veterinarius (Canadian distribution) sales Boyd Shearon, Account Manager agreement no. 40014103. (CAB International, CAB 913-322-1643 | Cell 215-287-7871 | bshearon@vetlearn.com Return undeliverable Canadian Abstracts, CAB Health); and Agricola (Library of Congress). addresses to MediMedia, CLASSIFIED ADVERTISING PO Box 7224, Windsor, ON Article retrieval systems include The Genuine Article Liese Dixon, Classified Advertising Specialist N9A 0B1. Printed in USA. (ISI), The Copyright Clear- 800-920-1695 | classifieds@vetlearn.com | www.vetclassifieds.com ance Center, Inc., University Compendium: Continuing EXECUTIVE OFFICER Education for Veterinarians® Microfilms International, and Source One (Knight-Ridder Derrick Kraemer, President (ISSN 1940-8307) Information, Inc.). Yearly author and subject indexes CIRCULATION for Compendium are pub- Barbara Horan, Circulation Specialist lished each December. Gina Donnelly, Customer Service Supervisor 800-426-9119, option 2 | info.vls@medimedia.com CompendiumVet.com 1
  4. 4. January 2009 Vol 31(1) CompendiumVet.com | Peer Reviewed | Listed in MEDLINE EDITORIAL BOARD Anesthesia Internal Medicine Nora S. Matthews, DVM, DACVA Dana G. Allen, DVM, MSc, DACVIM AMERICAN Texas A&M University Ontario Veterinary College BOARD OF Cardiology Internal Medicine and Emergency/ VETERINARY Bruce Keene, DVM, MSc, DACVIM Critical Care PRACTITIONERS North Carolina State University Alison R. Gaynor, DVM, DACVIM (ABVP) REVIEW (Internal Medicine), DACVECC Clinical Chemistry, Hematology, North Grafton, Massachusetts BOARD and Urinalysis Betsy Welles, DVM, PhD, DACVP Nephrology Eric Chafetz, DVM, DABVP Auburn University Catherine E. Langston, DVM, ACVIM (Canine/Feline) Animal Medical Center Dentistry Vienna Animal Hospital New York, New York Gary B. Beard, DVM, DAVDC Vienna, Virginia Auburn University Neurology Canine and Feline Medicine EDITOR IN CHIEF R. Michael Peak, DVM, DAVDC Curtis W. Dewey, DVM, MS, DACVIM (Neurology), DACVS Henry E. Childers, DVM, Douglass K. Macintire, The Pet Dentist—Tampa Bay Veterinary Cornell University Hospital for Animals Dentistry DABVP (Canine/Feline) DVM, MS, DACVIM, DACVECC Largo, Florida Oncology Cranston Animal Hospital Department of Clinical Sciences Ann E. Hohenhaus, DVM, DACVIM Cranston, Rhode Island College of Veterinary Medicine Emergency/Critical Care and (Oncology and Internal Medicine) Canine and Feline Medicine Auburn University, AL 36849 Respiratory Medicine Animal Medical Center Lesley King, MVB, MRCVS, DACVECC, New York, New York DACVIM David E. Harling, DVM, University of Pennsylvania Gregory K. Ogilvie, DVM, DACVIM DABVP (Canine/Feline), (Internal Medicine and Oncology) DACVO Endocrinology and Metabolic Disorders CVS Angel Care Cancer Center and Special Reidsville Veterinary Hospital Marie E. Kerl, DVM, ACVIM, ACVECC Care Foundation for Companion Animals Reidsville, North Carolina University of Missouri-Columbia San Marcos, California Canine and Feline Medicine, EXECUTIVE Epidemiology Ophthalmology Ophthalmology ADVISORY Philip H. Kass, DVM, MPVM, MS, PhD, David A. Wilkie, DVM, MS, DACVO BOARD DACVPM The Ohio State University Jeffrey Katuna, DVM, DABVP University of California, Davis MEMBERS Parasitology Wellesley-Natick Veterinary Exotics Byron L. Blagburn, MS, PhD Hospital Avian Behavior Auburn University Natick, Massachusetts Thomas N. Tully, Jr, DVM, MS, DABVP Sharon L. Crowell-Davis, (Avian), ECAMS David S. Lindsay, PhD Canine and Feline Medicine DVM, PhD, DACVB Louisiana State University Virginia Polytechnic Institute The University of Georgia and State University Robert J. Neunzig, DVM, Reptiles DABVP (Canine/Feline) Douglas R. Mader, MS, DVM, DABVP (DC) Pharmacology Dermatology Marathon Veterinary Hospital Katrina L. Mealey, DVM, PhD, DACVIM, The Pet Hospital Craig E. Griffin, DVM, Marathon, Florida DACVCP Bessemer City, North Carolina Washington State University Canine and Feline Medicine DACVD Small Mammals Animal Dermatology Clinic Karen Rosenthal, DVM, MS, DABVP Rehabilitation and Physical Therapy San Diego, California (Avian) Darryl Millis, MS, DVM, DACVS University of Pennsylvania University of Tennessee Wayne S. Rosenkrantz, Feline Medicine Surgery Compendium is a DVM, DACVD Michael R. Lappin, DVM, PhD, Philipp Mayhew, BVM&S, MRCVS, refereed journal. Articles Animal Dermatology Clinic DACVIM (Internal Medicine) DACVS Colorado State University Columbia River Veterinary Specialists published herein have Tustin, California been reviewed by at least Vancouver, Washington Margie Scherk, DVM, DAVBP (Feline Medicine) C. Thomas Nelson, DVM two academic experts on Nutrition the respective topic and Cats Only Veterinary Clinic Animal Medical Center Kathryn E. Michel, DVM, Vancouver, British Columbia Anniston, Alabama by an ABVP practitioner. MS, DACVN Gastroenterology Surgery and Orthopedics University of Pennsylvania Debra L. Zoran, DVM, MS, PhD, Ron Montgomery, DVM, MS, DACVS DACVIM (Internal Medicine) Auburn University Surgery Texas A&M University Any statements, claims, or product Toxicology Elizabeth M. Hardie, endorsements made in Compendium Infectious Disease Tina Wismer, DVM, DABVT, DABT DVM, PhD, DACVS are solely the opinions of our authors Derek P. Burney, PhD, DVM ASPCA National Animal Poison Control and advertisers and do not necessarily North Carolina State Gulf Coast Veterinary Specialists Center reflect the views of the Publisher or University Houston, Texas Urbana, Illinois Editorial Board. 2 CompendiumVet.com
  5. 5. Service... SevoFlo® (sevoflurane) anesthesia—with expert service, support and training—is smart, efficient and profitable for your practice. Only SevoFlo— You’re probably familiar with SevoFlo. But, do you realize how Abbott Animal available through Health’s exceptional service and product support helps you, your patients and all major distributors your practice? —provides four unique benefits: SevoFlo and Abbott Animal Health can help your surgical suite run efficiently 1. A minimum of and profitably. Our team of local representatives provides support and advice. 300 ppm water In addition, our technical support department and panel of anesthesiologists 2. Shatter-resistant are standing by to discuss techniques and equipment. Abbott Animal Health PEN bottles also helps educate you and your staff by providing “lunch-and-learns,” in-clinic 3. Local Abbott training materials and CE sponsorships—we’re committed to the veterinary representatives community. and expert advice 4. Commitment To learn more about SevoFlo, our other anesthetics and our commitment to training to serving you, contact Abbott Animal Health Customer Service at and education 888-299-7416 or visit www.abbottanimalhealth.com. Important Information: How Supplied: SevoFlo is packaged in amber colored bottles containing 250 mL sevoflurane. Indications: SevoFlo is indicated for induction and maintenance of general anesthesia in dogs. Warnings, Precautions, and Contraindications: Like other inhalation anesthetics, sevoflurane is a profound respiratory depressant. Respiration must be monitored closely in the dog and supported when necessary with supplemental oxygen and/or assisted ventilation. Due to sevoflurane’s low solubility in blood, increasing concentration may result in rapid hemodynamic changes compared to other volatile anesthetics. SevoFlo is contraindicated in dogs with a known sensitivity to sevoflurane or other halogenated agents. Adverse Reactions: The most frequently reported adverse reactions during maintenance anesthesia were hypotension, followed by tachypnea, muscle tenseness, excitation, apnea, muscle fasciculations and emesis. See package insert for full prescribing information. See Page 4 for Product Information Summary SEVO-186 June 2008 ©2008 Abbott Laboratories
  6. 6. PRECAUTIONS: Halogenated volatile anesthetics can react with desiccated decreased at hourly intervals, from 500 mL/min (36 and 18 ppm Compound A) to 250 SevoFlo® 5458 carbon dioxide (CO2) absorbents to produce carbon monoxide (CO) that may mL/min (43 and 31 ppm) to 50 mL/min (61 and 48 ppm).8 (sevoflurane) result in elevated carboxyhemoglobin levels in some patients. To prevent this Fluoride ion metabolite: Sevoflurane is metabolized to hexafluoroisopropanol (HFIP) reaction, sevoflurane should not be passed through desiccated soda lime or with release of inorganic fluoride and CO2. Fluoride ion concentrations are influenced by Inhalation Anesthetic For Use in Dogs barium hydroxide lime. the duration of anesthesia and the concentration of sevoflurane. Once formed, HFIP is Caution: Federal law restricts this drug to use by or on the order of a Replacement of Desiccated CO2 Absorbents: When a clinician suspects rapidly conjugated with glucuronic acid and eliminated as a urinary metabolite. No other licensed veterinarian. that the CO2 absorbent may be desiccated, it should be replaced before metabolic pathways for sevoflurane have been identified. In humans, the fluoride ion DESCRIPTION: SevoFlo (sevoflurane), a volatile liquid, is a halogenated administration of sevoflurane. The exothermic reaction that occurs with half-life was prolonged in patients with renal impairment, but human clinical trials general inhalation anesthetic drug. Its chemical name is fluoromethyl 2,2,2- sevoflurane and CO2 absorbents is increased when the CO2 absorbent contained no reports of toxicity associated with elevated fluoride ion levels. In a study in trifluoro-l- (trifluoromethyl) ethyl ether, and its structural formula is: becomes desiccated, such as after an extended period of dry gas flow through which 4 dogs were exposed to 4% sevoflurane for 3 hours, maximum serum fluoride the CO2 absorbent canisters. Extremely rare cases of spontaneous fire in the concentrations of 17.0-27.0 mcmole/L were observed after 3 hours of anesthesia. respiratory circuit of the anesthesia machine have been reported during Serum fluoride fell quickly after anesthesia ended, and had returned to baseline by 24 sevoflurane use in conjunction with the use of a desiccated CO2 absorbent, hours post-anesthesia. In a safety study, eight healthy dogs were exposed to specifically those containing potassium hydroxide (e.g. BARALYME). sevoflurane for 3 hours/day, 5 days/week for 2 weeks (total 30 hours exposure) at a Potassium hydroxide containing CO2 absorbents are not recommended for use flow rate of 500 mL/min in a semi-closed, rebreathing system with soda lime. Renal Sevoflurane Physical Constants are: with sevoflurane. An unusually delayed rise in the inspired gas concentration toxicity was not observed in the study evaluation of clinical signs, hematology, serum Molecular weight 200.05 (decreased delivery) of sevoflurane compared with the vaporizer setting may chemistry, urinalysis, or gross or microscopic pathology. Boiling point at 760 mm Hg 58.6°C indicate excessive heating of the CO2 absorbent canister and chemical DRUG INTERACTIONS: In the clinical trial, sevoflurane was used safely in dogs that Specific gravity at 20°C 1.520-1.525 g/mL breakdown of sevoflurane. The color indicator of most CO2 absorbent may not received frequently used veterinary products including steroids and heartworm and flea Vapor pressure in mm Hg at 20°C 157 change upon desiccation. Therefore, the lack of significant color change preventative products. at 25°C 197 should not be taken as an assurance of adequate hydration. CO2 absorbents Intravenous Anesthetics: Sevoflurane administration is compatible with barbiturates, at 36°C 317 should be replaced routinely regardless of the state of the color indicator. propofol and other commonly used intravenous anesthetics. Benzodiazepines and Distribution Partition Coefficients at 37°C: Opioids: Benzodiazepines and opioids would be expected to decrease the MAC of The use of some anesthetic regimens that include sevoflurane may result in Blood/Gas 0.63-0.69 sevoflurane in the same manner as other inhalational anesthetics. Sevoflurane is bradycardia that is reversible with anticholinergics. Studies using sevoflurane Water/Gas 0.36 compatible with benzodiazepines and opioids as commonly used in surgical practice. anesthetic regimens that included atropine or glycopyrrolate as premedicants Olive Oil/Gas 47-54 Phenothiazines and Alpha2-Agonists: Sevoflurane is compatible with phenothiazines showed these anticholinergics to be compatible with sevoflurane in dogs. Brain/Gas 1.15 and alpha2- agonists as commonly used in surgical practice. During the induction and maintenance of anesthesia, increasing the Mean Component/Gas Partition Coefficients at 25°C for Polymers Used In a laboratory study, the use of the acepromazine/oxymorphone/ thiopental/sevoflurane concentration of sevoflurane produces dose dependent decreases in blood Commonly in Medical Applications: anesthetic regimen resulted in prolonged recoveries in eight (of 8) dogs compared to pressure and respiratory rate. Due to sevoflurane’s low solubility in blood, Conductive rubber 14.0 recoveries from sevoflurane alone. these changes may occur more rapidly than with other volatile anesthetics. Butyl rubber 7.7 CLINICAL EFFECTIVENESS: Excessive decreases in blood pressure or respiratory depression may be Polyvinyl chloride 17.4 The effectiveness of sevoflurane was investigated in a clinical study involving 196 dogs. related to depth of anesthesia and may be corrected by decreasing the Polyethylene 1.3 Thirty dogs were mask-induced with sevoflurane using anesthetic regimens that inspired concentration of sevoflurane. RESPIRATION MUST BE MONITORED included various premedicants. During the clinical study, one hundred sixty-six dogs CLOSELY IN THE DOG AND SUPPORTED WHEN NECESSARY WITH Sevoflurane is nonflammable and nonexplosive as defined by the requirements of received sevoflurane maintenance anesthesia as part of several anesthetic regimens SUPPLEMENTAL OXYGEN AND/OR ASSISTED VENTILATION. The low International Electrotechnical Commission 601-2-13. Sevoflurane is a clear, that used injectable induction agents and various premedicants. The duration of solubility of sevoflurane also facilitates rapid elimination by the lungs. colorless, stable liquid containing no additives or chemical stabilizers. anesthesia and the choice of anesthetic regimens were dependent upon the procedures The use of sevoflurane in humans increases both the intensity and duration of Sevoflurane is nonpungent. It is miscible with ethanol, ether, chloroform and that were performed. Duration of anesthesia ranged from 16 to 424 minutes among the neuromuscular blockade induced by nondepolarizing muscle relaxants. The petroleum benzene, and it is slightly soluble in water. Sevoflurane is stable when individual dogs. Sevoflurane vaporizer concentrations during the first 30 minutes of use of sevoflurane with nondepolarizing muscle relaxants has not been stored under normal room lighting condition according to instructions. maintenance anesthesia were similar among the various anesthetic regimens. The evaluated in dogs. INDICATIONS: SevoFlo is indicated for induction and maintenance of general quality of maintenance anesthesia was considered good or excellent in 169 out of 196 Compromised or debilitated dogs: Doses may need adjustment for geriatric or anesthesia in dogs. dogs. The table shows the average vaporizer concentrations and oxygen flow rates debilitated dogs. Because clinical experience in administering sevoflurane to DOSAGE AND ADMINISTRATION: Inspired Concentration: The delivered during the first 30 minutes for all sevoflurane maintenance anesthesia regimens: dogs with renal, hepatic and cardiovascular insufficiency is limited, its safety in concentration of SevoFlo should be known. Since the depth of anesthesia may these dogs has not been established. be altered easily and rapidly, only vaporizers producing predictable percentage Average Average Average Average Breeding dogs: The safety of sevoflurane in dogs used for breeding purposes, Vaporizer Vaporizer Oxygen Oxygen concentrations of sevoflurane should be used. Sevoflurane should be vaporized during pregnancy, or in lactating bitches, has not been evaluated. Concentrations Concentrations Flow Flow using a precision vaporizer specifically calibrated for sevoflurane. Sevoflurane Neonates: The safety of sevoflurane in young dogs (less than 12 weeks of among among Rates Rates contains no stabilizer. Nothing in the drug product alters calibration or operation age) has not been evaluated. Anesthetic Individual among among of these vaporizers. The administration of general anesthesia must be HUMAN SAFETY: Not for human use. Keep out of reach of children. Regimens Dogs Anesthetic Individual individualized based on the patient’s response. WHEN USING SEVOFLURANE, Regimens Dogs Operating rooms and animal recovery areas should be provided with 3.31 - 3.63% 1.6 - 5.1% 0.97 - 1.31 0.5 - 3.0 PATIENTS SHOULD BE CONTINUOUSLY MONITORED AND FACILITIES adequate ventilation to prevent the accumulation of anesthetic vapors. L/minute L/minute FOR MAINTENANCE OF PATENT AIRWAY, ARTIFICIAL VENTILATION, AND There is no specific work exposure limit established for sevoflurane. However, OXYGEN SUPPLEMENTATION MUST BE IMMEDIATELY AVAILABLE. the National Institute for Occupational Safety and Health has recommended an During the clinical trial, when a barbiturate was used for induction, the times to Replacement of Desiccated CO2 Absorbents: When a clinician suspects that 8 hour time-weighted average limit of 2 ppm for halogenated anesthetic agents extubation, sternal recumbency and standing recovery were longer for dogs that the CO2 absorbent may be desiccated, it should be replaced. An exothermic in general. Direct exposure to eyes may result in mild irritation. If eye exposure received anesthetic regimens containing two preanesthetics compared to regimens reaction occurs when sevoflurane is exposed to CO2 absorbents. This reaction is containing one preanesthetic. Recovery times were shorter when anesthetic regimens occurs, flush with plenty of water for 15 minutes. Seek medical attention if increased when the CO2 absorbent becomes desiccated (see PRECAUTIONS). irritation persists. Symptoms of human overexposure (inhalation) to used sevoflurane or propofol for induction. The quality of recovery was considered good Premedication: No specific premedication is either indicated or contraindicated sevoflurane vapors include respiratory depression, hypotension, bradycardia, or excellent in 184 out of 196 dogs. Anesthetic regimen drug dosages, physiological with sevoflurane. The necessity for and choice of premedication is left to the shivering, nausea and headache. If these symptoms occur, remove the responses, and the quality of induction, maintenance and recovery were comparable discretion of the veterinarian. Preanesthetic doses for premedicants may be between 10 sighthounds and other breeds evaluated in the study. During the clinical individual from the source of exposure and seek medical attention. The lower than the label directions for their use as a single medication.1 material safety data sheet (MSDS) contains more detailed occupational safety study there was no indication of prolonged recovery times in the sighthounds. Induction: For mask induction using sevoflurane alone, inspired concentrations information. For customer service, adverse effects reporting, and/or a HOW SUPPLIED: SevoFlo (sevoflurane) is packaged in amber colored bottles up to 7% sevoflurane with oxygen are employed to induce surgical anesthesia in copy of the MSDS, call (888) 299-7416. containing 250 mL sevoflurane, List 5458. the healthy dog. These concentrations can be expected to produce surgical STORAGE CONDITIONS: Store at controlled room temperature 15°-30°C (59°-86°F). CLINICAL PHARMACOLOGY: Sevoflurane is an inhalational anesthetic anesthesia in 3 to 14 minutes. Due to the rapid and dose dependent changes agent for induction and maintenance of general anesthesia. The Minimum REFERENCES: in anesthetic depth, care should be taken to prevent overdosing. Alveolar Concentration (MAC) of sevoflurane as determined in 18 dogs is 1. Plumb, D.C. ed., Veterinary Drug Handbook, Second Edition, University of Iowa Respiration must be monitored closely in the dog and supported when 2.36%.2 MAC is defined as that alveolar concentration at which 50% of healthy Press, Ames, IA: p. 424 (1995). necessary with supplemental oxygen and/or assisted ventilation. patients fail to respond to noxious stimuli. Multiples of MAC are used as a 2. Kazama, T. and Ikeda, K., Comparison of MAC and the rate of rise of alveolar Maintenance: SevoFlo may be used for maintenance anesthesia following mask guide for surgical levels of anesthesia, which are typically 1.3 to 1.5 times the concentration of sevoflurane with halothane and isoflurane in the dog. Anesthesiology. induction using sevoflurane or following injectable induction agents. The MAC value. Because of the low solubility of sevoflurane in blood (blood/gas 68: 435-437 (1988). concentration of vapor necessary to maintain anesthesia is much less than that partition coefficient at 37°C = 0.63-0.69), a minimal amount of sevoflurane is 3. Scheller, M.S., Nakakimura, K., Fleischer, J.E. and Zornow, M.H., Cerebral effects of required to induce it. Surgical levels of anesthesia in the healthy dog may be required to be dissolved in the blood before the alveolar partial pressure is in sevoflurane in the dog: Comparison with isoflurane and enflurane. Brit. J. Anesthesia maintained with inhaled concentrations of 3.7-4.0% sevoflurane in oxygen in the equilibrium with the arterial partial pressure. During sevoflurane induction, 65: 388-392 (1990). absence of premedication and 3.3-3.6% in the presence of premedication. The there is a rapid increase in alveolar concentration toward the inspired 4. Frink, E.J., Morgan, S.E., Coetzee, A., Conzen, P.F. and Brown, B.R., Effects of use of injectable induction agents without premedication has little effect on the concentration. Sevoflurane produces only modest increases in cerebral blood sevoflurane, halothane, enflurane and isoflurane on hepatic blood flow and oxygenation concentrations of sevoflurane required for maintenance. Anesthetic regimens that flow and metabolic rate, and has little or no ability to potentiate seizures.3 in chronically instrumented greyhound dogs. Anesthesiology 76: 85-90 (1992). include opioid, alpha2-agonist, benzodiazepine or phenothiazine premedication Sevoflurane has a variable effect on heart rate, producing increases or 5. Kazama, T. and Ikeda, K., The comparative cardiovascular effects of sevoflurane will allow the use of lower sevoflurane maintenance concentrations. decreases depending on experimental conditions.4,5 Sevoflurane produces with halothane and isoflurane. J. Anesthesiology 2: 63-8 (1988). CONTRAINDICATIONS: SevoFlo is contraindicated in dogs with a known dose-dependent decreases in mean arterial pressure, cardiac output and 6. Bernard, J. M., Wouters, P.F., Doursout, M.F., Florence, B., Chelly, J.E. and Merin, sensitivity to sevoflurane or other halogenated agents. myocardial contraction.6 Among inhalation anesthetics, sevoflurane has low R.G., Effects of sevoflurane on cardiac and coronary dynamics in chronically WARNINGS: Sevoflurane is a profound respiratory depressant. DUE TO THE arrhythmogenic potential.7 Sevoflurane is chemically stable. No discernible instrumented dogs. Anesthesiology 72: 659-662 (1990). RAPID AND DOSE DEPENDENT CHANGES IN ANESTHETIC DEPTH, degradation occurs in the presence of strong acids or heat. Sevoflurane reacts 7. Hayaski, Y., Sumikawa, K., Tashiro, C., Yamatodani, A. and Yoshiya, I., RESPIRATION MUST BE MONITORED CLOSELY IN THE DOG AND through direct contact with CO2 absorbents (soda lime and barium hydroxide Arrhythmogenic threshold of epinephrine during sevoflurane, enflurane and isoflurane SUPPORTED WHEN NECESSARY WITH SUPPLEMENTAL OXYGEN lime) producing pentafluoroisopropenyl fluoromethyl ether (PIFE, C4H2F6O), anesthesia in dogs. Anesthesiology 69: 145-147 (1988). AND/OR ASSISTED VENTILATION. also known as Compound A, and trace amounts of pentafluoromethoxy 8. Muir, W.W. and Gadawski, J., Cardiorespiratory effects of low-flow and closed circuit In cases of severe cardiopulmonary depression, discontinue drug administration, isopropyl fluoromethyl ether (PMFE, C5H6F6O), also known as Compound B. inhalation anesthesia, using sevoflurane delivered with an in-circuit vaporizer and ensure the existence of a patent airway and initiate assisted or controlled Compound A: The production of degradants in the anesthesia circuit results concentrations of compound A. Amer. J. Vet. Res. 59 (5): 603-608 (1998). ventilation with pure oxygen. Cardiovascular depression should be treated with from the extraction of the acidic proton in the presence of a strong base plasma expanders, pressor agents, antiarrhythmic agents or other techniques as (potassium hydroxide and/or NaOH) forming an alkene (Compound A) from NADA 141-103, Approved by FDA appropriate for the observed abnormality. Due to sevoflurane’s low solubility in SevoFlo® is a registered trademark of Abbott Laboratories. sevoflurane. blood, increasing the concentration may result in rapid changes in anesthetic Compound A is produced when sevoflurane interacts with soda lime or barium Manufactured by Abbott Laboratories, North Chicago, IL depth and hemodynamic changes (dose dependent decreases in respiratory rate hydroxide lime. Reaction with barium hydroxide lime results in a greater 60064, USA and blood pressure) compared to other volatile anesthetics. Excessive decreases production of Compound A than does reaction with soda lime. Its concentration Product of Japan in blood pressure or respiratory depression may be corrected by decreasing or in a circle absorber system increases with increasing sevoflurane discontinuing the inspired concentration of sevoflurane. Under license from concentrations and with decreasing fresh gas flow rates. Sevoflurane Maruishi Pharmaceutical Co., LTD Potassium hydroxide containing CO2 absorbents (e.g. BARALYME®) are not degradation in soda lime has been shown to increase with temperature. Since 2-3-5, Fushimi-Machi, Chuo-Ku, recommended for use with sevoflurane. the reaction of carbon dioxide with absorbents is exothermic, this temperature Osaka, Japan ADVERSE REACTIONS: The most frequently reported adverse reactions during increase will be determined by the quantities of CO2 absorbed, which in turn maintenance anesthesia were hypotension, followed by tachypnea, muscle For customer service call (888) 299-7416. will depend on fresh gas flow in the anesthetic circle system, metabolic status tenseness, excitation, apnea, muscle fasciculations and emesis. of the patient and ventilation. Although Compound A is a dose-dependent Infrequent adverse reactions include paddling, retching, salivation, cyanosis, ©Abbott 8/2006 nephrotoxin in rats, the mechanism of this renal toxicity is unknown. Two Taken from Commodity Number 03-5474/R6, SevoFlo, sevoflurane, package insert, January 11, 2007 premature ventricular contractions and excessive cardiopulmonary depression. spontaneously breathing dogs under sevoflurane anesthesia showed Transient elevations in liver function tests and white blood cell count may occur increases in concentrations of Compound A as the oxygen flow rate was with sevoflurane, as with the use of other halogenated anesthetic agents. SEVO-152 January 2007 page 1 of 1 ©2007 Abbott Laboratories
  7. 7. E Each CE article is accredited for 3 contact hours by CE A Auburn University College of Veterinary Medicine. Section Name January 2009 Vol 31(1) Features 8 Understanding Behavior CompendiumVet.com | Peer Reviewed | Listed in MEDLINE Behavior Assessment: The First Appointment ❯❯ Sharon L. Crowell-Davis Once a behavior prob- An In-Depth Look FREE lem has been identi- fied and described, the 14 The Diagnostic Approach to CE circumstances in which it Fever of Unknown Origin in D Dogs occurs must be clarified. ❯❯ Julie Flood This is the second article in this series on behav- FREE ior patient assessment. 26 The Diagnostic Approach to CE Fever of Unknown Origin in C t Cats 22 Focus on Nutrition NEW ❯❯ Julie Flood Using a Diet History to Improve Fever is a common clinical sign in dogs and Adherence to Dietary Recommendations i cats, but its cause is not always apparent. ❯❯ Kathryn E. Michel These articles present a thorough overview of physical examination findings and diag- The first article in this quarterly series explains nostic tests that can help guide diagnosis of how to effectively use diet history forms and the underlying condition. what information is most important. 33 Immunosuppressive Therapy for Canine ine Immune-Mediated Hemolytic Anemia FREE ❯❯ Suliman Al-Ghazlat CE The author describes the range of current treatment options for dogs with this potentially deadly condition. 47 Focus on Nutrition Sample Diet History Form This form is also downloadable from CompendiumVet.com. Departments 6 Editorial: Clinical Snapshot Focus on Nutrition PAGE 11 ❯❯ Kathryn E. Michel 14 7 CompendiumVet.com ©2009 iofoto/Shutterstock.com 11 Clinical Snapshot A Dog with “Bumps” on its Skin On the Cover ❯❯ Karen A. Moriello Starting on page 14, Dr. Julie Flood de- scribes the diagnostic approach to fever 25 Letters of unknown origin in dogs and cats. 32 Product Forum 45 Classified Advertising Supplemental material to both articles 45 Market Showcase 46 Index to Advertisers is available at CompendiumVet.com. CompendiumVet.com 5
  8. 8. Editorial ❯❯ Kathryn E. Michel, DVM, MS, DACVN, University of Pennsylvania Focus on Nutrition The goal of this new quarterly column is to provide veterinary health professionals with state-of-the-art information on best practices for the nutritional management of companion animals. D etermining and implementing the The articles will be written by members appropriate dietary management of of the ACVN, the recognized specialty board companion animals have long been in this area of expertise. The column will recognized by the veterinary profession as also include information about the ACVN, the key components of maintaining wellness and services its diplomates can offer to practicing treating disease. Now, pet owners are increas- veterinarians, and resources for those who ingly aware of the benefits and risks that cer- may be interested in specializing in the field tain dietary habits may entail. In the present of nutrition. “information age,” it is a growing challenge for We all know that diet is a subject of great veterinary practitioners to stay abreast of this concern to many pet owners and one about dynamic field to be able to offer their clients which people often hold strong opinions. It accurate information about companion animal can be a sensitive subject to broach, and it is nutrition and diet choices and their patients often difficult to get clients to adhere to the the latest advances in nutritional management. dietary recommendations we make for their pets. I hope that Focus on Nutrition will help We all know that diet is a subject of great veterinary health professionals become more concern to many pet owners and one about informed on entering into and feel more con- fident when this subject a dialogue on diet which people often hold strong opinions. and dietary management with their clients to ensure the best possible outcome for their In order to help practitioners meet this patients. challenge, this issue of Compendium is launch- ing the Focus on Nutrition series in collabora- tion with the American College of Veterinary SHARE YOUR COMMENTS Nutrition (ACVN). This new column, which will Have something to say about this appear quarterly, is devoted to current topics in editorial or topic? Let us know: small animal nutrition. The goal is to provide E-MAIL editor@CompendiumVet.com veterinary health professionals with state-of- the-art information on best practices for the FAX 800-556-3288 nutritional management of companion animals, both to maintain wellness and to treat disease. 6 Compendium: Continuing Education for Veterinarians® | January 2009 | CompendiumVet.com