Emergency Procedures for the Small Animal Veterinarian E-Book

Signe J. Plunkett

• Publisher: Saunders Ltd.
• Year: 2012
• eBook ISBN: 9780702054303
• Edition: 3
• Topic: Medicine
• Subtopic: Veterinary Medicine

The new edition of the hugely successful Emergency Procedures for the Small Animal Veterinarian gives you all the information you need to form a diagnosis quick and accurately, establish a prognosis and recommend treatment for a patient suffering and illness, injury or toxic event.Easy-to-read bullet-point text gives quick access to the most essential information needed to treat emergency cases quickly and efficiently. Loads of practical appendices of commonly used drugs and supplements, drugs in special circumstances (e.g. safe drugs in pregnancy, drugs to avoid in renal failure, etc.), clinical chemistry and laboratory data, conversion tables, and many more, are included for easy reference to essential data.With step-by-step coverage of cardiopulmonary emergencies, trauma gastrointestinal emergencies, toxicological events, a greatly expanded chapter on exotic pets, and much more, Emergency Procedures for the Small Animal Veterinarian gives you the facts you need to help you save more lives faster!

• All you need to know to manage every small animal emergency case you will encounter
• Many excellent and practical appendices of drugs, poisons, lab data, haematology
• Takes the diagnosis-prognosis-treatment approach to every emergency situation
• Easy-to-access format, with concise text and lots of lists
• Divided into organ systems, making it easy to locate information in a hurry
• Handy information on what to tell the owner in emergency injury situations
• Expanded chapter on Emergencies in Exotic Species
• Text updated throughout
• Information on drugs is updated
• New cover design to make the new edition stand out
• Flexicover to protect the book against heavy usage - this is not a book that will remain on the shelves

1

Supportive therapy

Acid–base disturbances

Evaluation of the blood pH, bicarbonate (HCO₃⁻),

and base excess may be very helpful in the assessment of a critically ill or injured animal. Arterial blood samples are necessary to evaluate the respiratory status and are the preferred sample, but venous blood samples are helpful to evaluate the status of the patient at the cellular level.

The normal arterial blood gas reference ranges for dogs and cats inspiring room air are listed in Table 1.1.

Table 1.1

Typical reference ranges for normal arterial blood gas values for dogs and cats inspiring room air

	Dog	Cat
pH	7.41 (7.35–7.46)	7.39 (7.31–7.46)
(mm Hg)	37 (31–43)	31 (25–37)
[HCO3^−] (mEq/L)	22 (19–26)	18 (14–22)
(mm Hg)	92 (81–103)	107 (95–118)

Evaluation of blood gas results is a process involving many steps.

1. Determine whether the pH is normal.

2. Evaluate the partial pressure of carbon dioxide (P_CO2) – the respiratory component.

3. Evaluate the bicarbonate concentration [HCO₃⁻] – the nonrespiratory component.

4. What is the primary disorder? The direction of the expected changes are shown in Table 1.2.

Table 1.2

The changes in simple primary acid–base disorders

Disorder	pH		[HCO3^−]
Respiratory acidosis	↓	↑	↑ or normal
Respiratory alkalosis	↑	↓	↓ or normal
Nonrespiratory (Metabolic) acidosis	↓	↓	↓
Nonrespiratory (Metabolic) alkalosis	↑	↑	↑

5. Is the secondary or adaptive response as expected? The expected responses are shown in Table 1.3.

Table 1.3

Expected compensatory response in simple acid–base disturbances in dogs and cats*

		Clinical guide for compensation
Disturbance	Primary change	Dogs	Cats^†
Metabolic acidosis	Each 1 mEq/L ↓ HCO3^−	↓ by 0.7 mm Hg	does not change
Metabolic alkalosis	Each 1 mEq/L ↑ HCO3^−	↑ by 0.7 mm Hg	↑ by 0.7 mm Hg
Respiratory acidosis
Acute	Each 1 mm Hg ↑	HCO3^− ↑ by 0.15 mEq/L	HCO3^− ↑ by 0.15 mEq/L
Chronic	Each 1 mm Hg ↑	HCO3^− ↑ by 0.35 mEq/L	Unknown
Long-standing^‡	Each 1 mm Hg ↑	HCO3^− ↑ by 0.55 mEq/L	Unknown
Respiratory alkalosis
Acute	Each 1 mm Hg ↓	HCO3^− ↓ by 0.25 mEq/L	HCO3^− ↓ by 0.25 mEq/L
Chronic	Each 1 mm Hg ↓	HCO3^− ↓ by 0.55 mEq/L	Similar to dogs^§

^*From DiBartola SP (ed), Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice, 3rd edn, St Louis, Elsevier, 2006, p 298, reprinted with permission from Elsevier Ltd. Data in dogs from de Morais & DiBartola (1991). See DiBartola (2006) for reference in cats.

^†Data from cats are derived from a very limited number of cats.

^‡More than 30 days.

^§Exact degree of compensation has not been determined, but in cats with chronic respiratory alkalosis maintain normal arterial pH.

6. Which disease process(es) is(are) responsible for the acid–base disorder?

Respiratory acidosis

Respiratory acidosis or primary hypercapnia indicates hypoventilation and hypoxemia. The blood pH is decreased, the

is increased and, with compensation, the HCO₃⁻ increases.

Sympathetic activation, increased cardiac output and possibly tachyarrhythmias may occur in the presence of moderately elevated

. As the

increases, intracranial pressure and cerebral blood flow increase. Disorientation, narcosis, and coma may occur at extremely high

levels (60–70 mm Hg).

Causes of respiratory acidosis include:

• Depression of the respiratory center

○ Associated with medications (inhalant anesthetics, opioids, barbiturates)

○ Neurologic disease

– Cervical spinal cord lesion

– Brainstem lesion

• Neuromuscular disease

○ Myasthenia gravis

○ Botulism

○ Tetanus

○ Tick paralysis

○ Severe hypokalemia

○ Associated with medications or chemicals (organophosphates, aminoglycosides)

• Obstruction of large airways

○ Aspiration

○ Kinked or plugged endotracheal tube

○ Tracheal co...

Table of contents

• Cover image
• Title Page
• Table of Contents
• Dedication
• Copyright
• Preface
• Acknowledgments
• List of contributors
• 1 Supportive therapy
• 2 Shock
• 3 Cardiovascular emergencies
• 4 Respiratory emergencies
• 5 Traumatic emergencies
• 6 Environmental emergencies
• 7 Dermatologic emergencies
• 8 Hematologic emergencies
• 9 Gastrointestinal emergencies
• 10 Metabolic and endocrine emergencies
• 11 Urinary emergencies and electrolyte disorders
• 12 Reproductive emergencies
• 13 Neurologic and ocular emergencies
• 14 Toxicologic emergencies
• 15 Emergencies in exotic species
• Appendices
• Index