Transcript Emergency Procedures

Emergency Procedures
Let the fun begin
Or
Passez le bon temp
Triage of Emergency Patients
Triage—to sort (Fr); most critical seen first
Should be done by RVT in busy practice; receptionist should not do it
• Initial exam (by RVT)
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Wear gloves
Animal muzzled (use discretion)
Minimize movement of patient
Initial Assessment (30-60 sec; from rostral direction)
• Mentation (level of consciousness)
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Alert
Verbally responsive
responsive to painful stimuli
Unresponsive
» Extend head/neck to provide clear airway; check for patency
• Breathing/respiratory pattern (shallow, labored, rapid, obstructed)
• Abnormal body/limb posture (fracture, paralysis)
• Presence of blood or other material around patient
Triage of Emergency Patients
– Initial Assessment (continued)
• Breathing/respiratory pattern
– Total/Partial blockage of airways (Requires immediate Rx)
» Exaggerated inspirations
» Nasal flare, open mouth, extended head/neck
» Cyanosis
– Breathing assessment
» Watch chest wall movement
» Auscult lungs bilaterally to r/o hemo- or pneumothorax
Triage of Emergency Patients
– Vital signs (taken after initial assessment)
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HR, pulse rate (same as HR?), strength
RR
mm color, cap refill
Temp
BP
– High HR, high BP→ pain
– High HR, low BP → hypovolemic shock
– Baseline data
• ECG (lead II)
• Chem panel, CBC
Triage of Emergency Patients
• Resuscitation (treatment to restore life/health)
– Analgesics for pain once airway patency and heart beat are
established (these are critical for life)
– Control hemorrhage
• Pressure bandages (sterile gauze, laparotomy pads, towels)
– If bleed thru, do not remove initial bandage, apply another on top
– On distal extremity, BP cuff can be placed proximal to wound (avoid
tourniquet if possible)
• External counterpressure using body wrap of pelvic limbs, pelvis, and
abdomen
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Insert urinary cath to monitor urine output
Use towels, cotton rolls, duct tape, etc
Monitor respirations (diaphragm/abdominal breathing compromised)
Leave on until hemodynamically stable (6-24 h)
Monitor BP during removal
» If BP drops >5 mm Hg, stop removal; infuse more fluids
» If BP continues to drop, reapply wrap
Triage of Emergency Patients
• History (mnemonic)
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A Allergies
M Medications
P Past History
L Lasts (meals, defecation, urination, medication)
E Events (What is the problem now?)
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How long since injury
Cause of injury (HBC, dog fight, gunshot)
Evidence of loss of consciousness
Blood loss?
Deterioration/improvement since accident (good indicator of
Px)
• Any other underlying medical conditions/medications
Shock
• What is shock?
– General Public
• Psychological
– Medically
• Poor O2 delivery to tissues, esp brain
Shock
• Types of Shock:
– Cardiogenic—results from heart failure
• ↓ blood pumped by heart
• HCM, DCM, valvular insufficiency/stenosis
– Distributive—blood flow maldistribution (Vasodilation)
• From psychological shock
• Sepsis, anaphylaxis →↓arteriole resistance →loss of fluid from
vessels to interstitial spaces →↓ blood return to heart →↓BP
– Obstructive—physical obstruction in circ system
• HW disease →↓blood pumped by heart
• Gastric torsion →↓blood return to heart
– Hypovolemic—decreased intravascular volume
• Most common
• Blood loss, dehydration from vom/dia
Shock
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Pathophysiology (of hypovolemic shock)
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↓blood vol →↓venous return, ↓vent filling →↓stroke vol, ↓CO →↓BP
1. Compensation—Baroreceptors detect hypotension (↓BP)
a. Sympathetic reflex—(Epi, Norepi, cortisol released from adrenals)
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↑ HR, contractility
Constriction of arterioles (↑BP) to skin (cold, clammy), muscles,
kidneys, GI tract; not brain, heart
b. Renin (kidney)→angiotensin (blood)→aldosterone (adrenals) reflex
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↑ Na+ and water retention → ↑ intravascular vol (↑BP)
Shock
• Recognition
– History
• Trauma
• Vom/dia
– PE findings
• Stage I (compensated shock)
– Tachycardia
– Prolonged cap refill time
– Pale mm
• Stage II (decompensated shock)
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Tachycardia
Delayed cap refill time
Muddy mm (loss of pink color, more brown than pink)
BP is dropping
Altered mental state
• Stage III (irreversible shock)
– PE findings worsen; cannot revive; death will occur
Shock
• Rx (the goal of therapy is to improve O2 delivery)
– O2 supplementation
• Face mask
• O2 cage/hoods
• Transtracheal/nasal insufflation
– Venous access
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Cephalic
Saphenous
Jugular
Intraosseous
ulna
Shock
• Rx (continued: remember the goal of therapy is to improve O2 delivery)
– Fluid resuscitation (O2 delivery is improved by ↑CO)
1. Crystalloids
• Isotonic solutions (crystalloids; Na+, Cl-, K+, bicarb)
– Examples (body fluid=280-300 mOsm/L)
» Lactated Ringer’s (273 mOsm/L)
» Normal saline (0.9%) (308 mOsm/L)
– Dose: Dog 80-90 ml/kg/hr
Cat 50-55 ml/kg/hr
• Hypertonic solutions—when lg vol of fluid cannot be administered rapidly enough
– Examples—7.5% saline
– Causes fluid shift from intracellular space→ interstitial space→
intravascular space →↑vascular vol →↑venous return → ↑CO
– Also causes vasodilation → ↑ tissue perfusion
– Dose: 4-6 ml/kg over 5 min
• Hypotonic solutions should never be used for hypovolemic shock
– Examples—5% Dex in water (252 mOsm/L)
Shock
• Rx (continued: remember the goal of therapy is to improve O2 delivery)
– Fluid resuscitation (O2 delivery is improved by ↑CO)
2. Colloids—
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Large molecular wt solutions that do not leave vascular system
Better blood vol expanders than crystalloids
50-80% of infused vol stay in blood vessels
Examples
– Whole blood
– Plasma
– Dextran 70
Shock
• Rx (continued)
– Sympathomimetics
Use only after adequate fluid administration if BP and tissue
perfusion have not returned to normal
• Dopamine (Intropin®)
– 0.5-3.0 μg/kg/min
» Dilation of renal, mesenteric, coronary vessels
– 3.0-7.5 μg/kg/min
» ↑ contractility of heart
» ↑ HR
– >7.5μg/kg/min
» Vasoconstriction
• Dobutamine (Dobutrex®)
– 5-15 μg/kg/min
– ↑ contractility of heart (min effect on HR)
Shock
• Monitoring
Hemodynamic/metabolic sequelae of shock are continually changing
– Physical Parameters
• Respiratory
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Color of mm
RR and Tidal Vol adequate?
Breathing efforts smooth?
Breathing pattern regular?
Auscultation normal?
• Cardiovascular
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HR normal?
ECG normal?
Color of mm
Cap refill time (1-2 sec)
Urine production? (1-2 ml/kg/hr)
Weak pulse? → ↓stroke vol
Shock
• Monitoring
– Physiologic Monitoring Parameters
• O2 Saturation
– Pulse oximetry—noninvasive
– Normal: Hb saturations (SpO2)>95%
» SpO2<90%--serious hypoxemia
• Arterial BP—a product of CO, vascular capacity, blood
volume
– If one is subnormal, the other 2 try to compensate to maintain BP
Shock
• Monitoring
– Laboratory Parameters
• Hematocrit (PCV)
– Increase →dehydration
– Decrease →blood loss
• Electrolytes (what is that?)
– Proper balance needed for proper cell function
– Fluid therapy may alter the balance; supplement fluid as needed
• Arterial pH and blood gases
– PaCO2 tells how well patient is ventilating
» PaCO2 <35 mm Hg → hyperventilation
» PaCO2 >45 mm Hg → hypoventilation
– PaO2 Tells how well patient is being oxygenated
» PaO2 <80 mm Hg → hypoxemia
– pH tells acid/base status of patient
– <7.35 → acidosis
– >7.45 → alkalosis
Cardiopulmonary Resuscitation
(CPR)
Cardiopulmonary Arrest (CPA)—Heart stops, breathing stops
• Causes
• Anesthesia
– Dogs
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Trauma
Infections (GI, pneumonia)
Heart disease
Autoimmune disease
Malignancy
– Cats
• Trauma
• Infectious diseases
Cardiopulmonary Resuscitation
• Resuscitation Team Members
– Should be 3-5 members
• Team leader—Veterinarian or RVT with most experience
• All members have several responsibilities
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Provide ventilation
Chest compression
Establish IV line
Administer drugs
Attach monitoring equipment
Record resuscitation efforts
Monitor team’s effectiveness
• Teams should practice on a regular basis to stay sharp
Cardiopulmonary Resuscitation
• Facilities
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Adequate room for entire team and equipment
O2 source
Good lighting
Crash cart with all needed Rx (should be checked at beginning of each
shift)
• Defibrillators
• Electrocardiogram
• Suction
– Table to perform chest compression
• Grated surgery prep table not solid enough for chest compression
– Use board underneath patient
• Recognition
– RVT should ID patients at risk and observe any deterioration
– Preventing an arrest is easier than treating one
Cardiopulmonary Resuscitation
• Standard Emergency Supplies (on crash cart)
– Pharmaceuticals
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Atropine
Epinephrine
Vasopressin
2% lidocaine (w/o epi)
Na+ bicarb
Ca++ chloride or gluconate
Lactated Ringer’s, hypertonic saline,
dextran 70, hetastarch
– Airway access supplies
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--Venous access supplies
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Butterfly cath
IV caths
IV drip sets
Bone marrow needles
Syringes
Hypodermic needles (var sizes)
Adhesive tape
Tourniquet
--Miscellaneous supplies
Laryngoscope
Endotracheal tubes (variety of sizes)
Lubricating jelly
Roll gauze
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Gauze pads (3 x 3)
Stethoscope
Minor surgery pack
Suture material
Scalpel blades
Surgeon’s gloves
Cardiopulmonary Resuscitation
• Basic Life Support (Phase I)
– Remember the priorities (ABC; Airway, Breathing, Circulation)
• Establish patent Airway
– Endotracheal tube
– Tracheostomy tube for upper airway obstruction
– Suction to remove blood, mucus, pulmonary edema fluid, vomit
• Artificial ventilation (Breathing)
» Ambu-Bag
» Anesthetic machine
– Ventilate once every 3-5 sec
– Chest compressions in between breaths
CPR
• http://www.youtube.com/watch?v=VJGlsY
HI9cU
Cardiopulmonary Resuscitation
Entubation
Cardiopulmonary Resuscitation
• Basic Life Support (Phase I)
– Circulation
• External cardiac compression
– Lateral recumbency—one/both hands on thorax over heart (4th-5th
intercostal space)
– In larger patients, arms extended, elbows locked
– In small patients, thumb and first 2 fingers to compress chest
– Rate of compression: 80-120/min
Cardiopulmonary Resuscitation
• Basic Life Support (Phase I)
– Circulation
• Internal cardiac compression
– More effective than external compression
» ↑CO, ↑BP, higher survival rate
– Indications
» Rib fractures
» Pleural effusion
» Pneumothorax
» If not responsive after 5 min of external cardiac compression
– Preparation
» Clip hair ASAP, no surgical scrub
» Incision at 4th or 5th intercostal space
» With a gloved hand, compress heart between fingers and palm (Do
not puncture heart with finger tips or twist heart)
» After spontaneous beating returns, flush chest cavity with saline,
perform sterile scrub of skin and close
Cardiopulmonary Resuscitation
• Basic Life Support (Phase I)
– Assessing effectiveness (must be done frequently)
• Improved color of mm
• Palpable pulse during cardiopulmonary resuscitation (difficult)
• If efforts are not effective, do something differently
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Use different hand
Change person performing compression
Ventilate with every 2nd or 3rd chest compression
Compress chest where it is widest in lg breed dogs
Apply counter-pressure to abdomen (hand, sandbag)
» Prevents posterior displacement of diaphragm and increases
intrathoracic pressure
CPR
Cardiopulmonary Resuscitation
• Advanced Life Support (Phase II)
Add 2 priorities to ABC--D E (administer Drugs, Electrical—defibrillate)
– Drugs
• Fluids
– Lactated Ringer’s is standard (do not use Dextrose)
» Initial dose:
Dogs—40 ml/kg
(rapidly IV)
Cats—20 ml/kg
• Atropine—parasympatholytic effects (blocks parasympathetic effects)
– 0.02-0.04 mg/kg
– ↑HR
– ↓secretions
• Epinephrine—adrenergic effects
– 0.02-0.2 mg/kg
– Arterial and venous vasoconstriction→ ↑BP
Cardiopulmonary Resuscitation
• Advanced Life Support (Phase II)
Add 2 priorities to ABC--D E (administer Drugs, Electrical—defibrillate)
– Drugs (continued)
• 2% Lidocaine (Used to treat cardiac arrhythmias)
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Cats:
1-2 mg/kg
0.5-1.0 mg/kg
• Magnesium Sulfate or Chloride (For refractory ventricular fibrillation)
– 30 mg/kg over 2 min period
• Sodium bicarb (For metabolic acidosis)
– 0.5 mEq/kg per 5 min or cardiac arrest
• Vasopressin (ADH) (vasodilator)
– 0.8 U/kg
Cardiopulmonary Resuscitation
• Advanced Life Support (Phase II)
Add 2 priorities to ABC--D E (administer Drugs, Electrical—defibrillate)
– Drugs (continued)
• Route of drug administration
– Jugular vein—close to heart; drugs will get to heart quicker
– Cephalic, saphenous—follow drugs with 10-30 ml saline flush
– Intraosseous—intramedullary cannula into femur, humerus, wing of
ilium, tibial crest
– Intratracheal—for limited # of drugs: atropine, lidocaine, epinephrine
– Intracardiac—last resort; several complications can occur
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Speed of access
Technical ability
Difficulties encountered
Rate of drug delivery
Cardiopulmonary Resuscitation
• Advanced Life Support (Phase II)
Add 2 priorities to ABC--D E (administer Drugs, Electrical—defibrillate)
– Electrical—Defibrillate
• Purpose—eliminate asynchronous electrical activity in heart muscles
by depolarizing all cardiac muscle fibers; hopefully, the fibers will
repolarize uniformly and start beating with coordinated contractions
• Paddles (with electrical gel) placed on each side of chest
• Yell “CLEAR” before discharging electrical current
• Start with low charge and increase as needed
– External: 3-5 J/kg
– Internal: 0.2-0.4 J/kg
normal ECG
Ventricular fibrillation
Cardiopulmonary Resuscitation
• Prolonged Life Support (Phase III)
– Once heart is beating on its own, monitor the following:
• HR and rhythm
– Antiarrhythmic drugs
– Correct electrolyte abnormalities
• BP
• Peripheral perfusion
– Color of mm
– Cap refill time
– urine output
• RR and character of breathing
– Adequate breathing
– Auscultory sounds
• Mental status
• Improving or deteriorating
UC Davis study: survival rate at 1 wk for cardiac resuscitation patients
Dogs:
3.8%
Cats:
2.3%
Allergic Reactions
Anaphylaxis/Allergic reactions
Rare, life-threatening reactions to something injected or ingested
Untreated, it results in shock, resp/cardiac failure, and death
IgE Antibodies to allergen bind to mast cells; on subsequent exposure,
the Ag-Ab reaction causes massive release of histamine and other
inflammatory mediators
Histamine → vasodilation → ↓BP
• Initiating factors
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Insects
Vaccines
Antibiotics
Certain hormones
Other medications
Foods
Re-exposure
Anaphylaxis/Allergic reactions
• Signs
– Sudden onset of vom/diarrhea
– Shock
• Gums are pale
• Limbs are cold
• HR rapid, weak
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Face scratching (early sign)
Respiratory distress
Collapse
Seizures
Coma
Death
Anaphylaxis/Allergic reactions
• Rx (this is an extreme emergency)
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Eliminate cause
Epinephrine
H1 antihistamines (Diphenhydramine)
IV fluids
Corticosteroids
Oxygen
• Prevention
– There is no way to predict what will bring on an anaphylactic reaction the
first time
– Always inform vet if animal has had previous reaction to vaccine
– Owners should have an ‘epi-pen’ with them at all times
Heat Stroke
• Signs
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Rapid, frantic, noisy breathing
Tongue/mm bright red, thick saliva
Vomiting/diarrhea—may be bloody
Rectal temp up to 106º
Unsteady/stagger
Coma/death
Prevention
Heat Stroke (Hyperthermia)
Requires immediate treatment
Dogs do not cool as well as humans (don’t sweat)
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Left in hot car
Water deprivation
Obesity/older
Chained without shade in hot weather
Muzzled under a hot dryer
Short-nosed breed (esp Pug, Bulldog)/heavy coat
Heart/Resp disease or any condition that impairs
breathing or ability to cool body
– Lack of acclimatization/exercise
Heat Stroke
• Rx (cells break down at 107º)
– Mild cases: move dog to a/c building or car
– Temp>104º, immerged in cool water, hose down
– Temp>106º, cool water enema (cool to 103º)
STOP COOLING EFFORTS AT 103º
– IV fluids
– Corticosteroids
Heat Stroke
• Complications
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Can affect all organs in the body
Denatures proteins
Hypotension
Lactic acidosis
Decreased oxygen delivery
Electrolyte abnormalities => cerebral edema and
death
– Coagulopathies => DIC
– If survives the first 24 hrs, prognosis is more favorable
Pain Management
• Misconceptions about animal pain
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Animals do not experience pain
Pain doesn’t really affect how animal responds to treatment
Signs of pain are too subjective to be assessed
Pain is good because it limits activity
Analgesia interferes with accurate assessment of treatment
Pain management not major concern in LA (except horses)
Pain shows weakness/fragility (Lab vs Collie)
• Fresh ideas about animal pain
– Analgesia increases chance of recovery in critically ill
– Pain associated with diagnostic test should be minimized
– Morally correct thing to do
Pain Management
Pain Management
• Signs
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Vocalization
↑HR
↑RR
Restlessness, abnormal posturing, unwilling to move
↑ Body temperature
↑BP
Inappetence
Aggression
Facial expression, trembling
Depression, insomnia
Pain Management
• Sequelae to untreated pain
– Neuroendocrine responses
• Excessive release of pit, adr, panc hormones
– Cause immunosuppression and disturbances of growth, development,
and healing
– Cardiovascular compromise
• ↑BP, HR, intracranial pressure
– Coagulopathies
• ↑platelet reactivity, DIC
– Long-term recumbency
• Decubital ulcers
– Poor appetite/nutrition
• Hypoproteinemia→slow healing
Pain Management
• Pain Relief
– Nonpharmacologic interventions (differentiate pain vs stress)
• Give relief from:
– Boredom, Thirst, Anxiety, Need to urinate/defecate
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Clean bedding/padding
Reduce light/sound
Stroking pet, calming speech
Owner visits (±)
Minimize painful events (reduce #, improve skill [inject, blood draw]
Pain Management
• Questions the Vet Tech must continually ask (you are
in charge of pain meds)
– Is patient at acceptable comfort level
– Are there any contraindications to giving pain meds
– What is the appropriate (safe, effective) med for this patient
• Drug Options
Pain Management
– Nonsteroidal Antiinflammatory Drugs (NSAIDs)
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Most widely used
Extremely effective for acute pain
Most effective when used preemptively (before tissue injury)
Usually not adequate to manage surgical pain
COX-2 NSAIDs do not cause damage to stomach lining
– Opioids
• Most commonly used in critically injured animals
– Rapid onset of action; effective; safe
• 4 types of receptors
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μ: analgesia, sedation, and resp depression
Κ: analgesia and sedation
Δ: some analgesia, resp depression
Σ: depression, excitement, anxiety
• Side effects
– Vomiting, constipation, excitement, bradycardia, panting
• Metabolized by liver; excreted by kidneys
– Use caution with hepatic, renal disease
• Opioids
Pain Management
– Morphine sulfate (the gold standard)
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Used for max analgesia/sedation
Inexpensive
Side-effects: systemic hypotension, vomiting
Cats particularly sensitive
Dose:
Dogs—0.5-2.2 mg/kg SQ, IM; 0.1-0.5 mg/kg IV
Cats—0.1-0.5 mg/kg SQ, IM
– Oxymorphone
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10x potency of morphine
Much more expensive; less resp depression and GI stimulation
Side-effects: depression, sensory hypersensitivity
Dose:
0.05-0.1 mg/kg IV, IM
– Hydromorphone
• Similar effects of Oxymorphone
• More widely available, less expensive than Oxymorphone
• Dose:
Dog—0.1-0.2 mg/kg SQ, IM
Cat—0.05-0.1 mg/kg SQ, IM
• Opioids
Pain Management
– Fentanyl citrate
• Extremely potent
• Rapid onset, short duration when administered IM or IV
• Transdermal patch
– 3-day duration
– Shave hair
– Butorphanol Tartrate
• Κ agonist; μ antagonist
• Analgesic effect questionable (>1 h); good sedative (~2 h)
– More expensive than morphine
– Less vomiting, depression
• Dose Dog—0.2-0.8 mg/kg SQ, IM; 0.1-0.4 mg/kg IV (Half that dose
in Cat)
– Buprenorphine
• 30x potency of morphine; longer duration; transmucosal absorption
• Dose:
Dog/cat—0.01-0.03 mg/kg SQ, IM, IV, buccal mucosa
Pain Management
• Opioids
– Antagonists
• Naloxone HCl
– Reversal occurs within 1-2 min
– Can be used to reverse
anesthesia (Inovar-Vet)
Toxicologic Emergencies
• Signs will vary depending on character of toxic compound
– Anxiety (marijuana)
– Seizures
– Unresponsive, Coma
• Toxicity can result from exposure via many routes
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Ingestion—most common; usually accidental (angry neighbor?)
Inhalation
Skin contact—animals should be washed to remove toxin
Injection—either o.d. in vet hosp or recreational drug use
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Basic equip: IV cath, fluids, bandages, ECG, O2, crash cart
Emetics
Activated charcoal
Stomach tubes
Valium, muscle relaxers
Toxicologic Emergencies
• Top 10 Toxicoses (2005)
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Human medication—painkillers, NSAIDs, antidepressants
Insecticides—flea and tick
Rodenticides—anticoagulants
Veterinary medication—NSAIDs, HW
Household cleaners—bleach, detergents
Plants—sago palm, lily, azalea
Herbicides—
Chocolate—highest in food category
Home improvement products—solvents, adhesives, paint,
wood glue
– Fertilizers
Toxicologic Emergencies
• Hx—as thorough as possible
– May not know
– Legal issues
• Rx
– Treat clinical signs
• Seizures
• Anxiety
• Coma
valium, phenobarbital
valium
IV fluids
– Induce vomiting (if animal is able)
• Some poisons release toxic gases
– Zinc phosphide (gopher bait) releases phosphine gas (well vent room)
– Wear gloves to prevent topical exposure to you
– Be cautious of abnormal behavior
• Biting
Toxicologic Emergencies
• Prevent Further Damage
– Ocular exposure
• Rinse eyes with copious saline for 20-30 min
• Chemical burns treated with lubricating ointment
and suture lids closed
– Use corticosteroids only if corneal epithelium is
intact
– Topical exposure
• Bathe with mild detergent (liquid dish soap)
• Bather should wear protective clothing (gloves,
goggles)
• If toxic substance is a powder, vacuum before
bathing
Toxicologic Emergencies
– Ingestion
• Induce vomiting—if chemical not caustic; animal conscious, not
seizuring
– ipecac, apomorphine, Xylazine, H2O2 [not reliable], salt [not recom],
soapy water [not recom])
• Dilute caustic substances with milk, water
• Gastric lavage—large bore stomach tube; light anesthesia w/
endotrach tube
• Administer absorbents—activated charcoal inhibits GI absorption
– Give orally or via stom tube
• Enemas/cathartics to eliminate toxins more rapidly
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Toxicologic Emergencies
Specific toxicities
– Methylxanthines—↑HR, ↑RR,
mild diuretic
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Ex: caffeine, theobromine,
theophylline
• Found in: coffee, tea, stimulants,
chocolate
1. Chocolate (theobromine tox)
-Found in cocoa bean, colas, tea
-Contains all 3 methylxanthines
-Theobromine toxic to dogs and cats; cats
more finicky
-Toxic Dose: 250-500 mg/kg;
Milk
Chocolate—44 mg/oz,
Baking
Chocolate—390 mg/oz
Toxicologic Emergencies
Clinical Signs
anxiety, vom/dia, ↑HR, cardiac arrhythmias,
incontinence, ataxia, muscle tremors, abd pain,
hematuria, seizures, cyanosis, coma
Rx
induce vom, gastric lavage, carcoal, cathartics
Diazepam to control seizures
frequent bladder catheterizations—
methylxanthines can be resorbed
Toxicologic Emergencies
• Specific toxicities
– Methylxanthines
2. Caffeine
-found in coffee, tea, chocolate, colas, stimulant drugs
-Lethal dose: 140 mg/kg
Clinical signs
vomiting, diuresis, restlessness/hyperactivity, ↑HR, ↑RR, ataxia,
seizures, arrhythmias, death not common
Rx—same as theobromine
Toxicologic Emergencies
• Specific toxicities
– Rodenticides
1. Anticoagulants (warfarin, pindone, bromadiolone, brodifacoum,
chlorphacinone, difethialone, diphacinine, coumafuryl, dicoumarol,
difenamarol)
– Work by binding Vit K, which inhibits synthesis of prothrombin (Factor II) and
other clotting factors
– This effect occurs within 6-40 h in a dog; effect may last 1-4 wk
• Clinical signs (occur after depletion of clotting factors)
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Lethargy
Vom/dia with blood; melena
Anorexia
Ataxia
Dyspnea
Epistaxis, schleral hemorrhage, pale mm
• Rx
– Vit K: 3-5 mg/kg PO for up to 21 d depending on anticoagulant used
– Induce vomiting; activated charcoal
– Whole blood transfusion if anemic
Toxicologic Emergencies
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Specific toxicities
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Rodenticides
2. Cholecalciferol—Vit D3; used in Quintox, rampage, Rat-Be-Gone
-causes Ca++ reabsorption from bone, intestine, kidneys causing
hypercalcemia (>11.5 mg/dl) and cardiotoxicity
•
Clinical signs (12-36 h after ingestion)
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–
–
–
•
Dx
–
–
•
Anorexia
Vomiting
Muscle weakness
Constipation
Hx of exposure
Usually discovered on routine Chem panel (↑blood Ca++)
Rx
–
–
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Induce vom/activated charcoal if ingestion occurred with 2 h
Furosemide x 2-4 wk; increases Ca++ excretion in urine
Prednisone x 2-4 wk; decreases Ca++ reabsorption from bones/intesine
Calcitonin to lower blood Ca++ concentration
Toxicologic Emergencies
•
Specific toxicities
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Rodenticides
3. Bromethalin
-uncoupler of oxidative phosphorylation in CNS (stops production of ATP)
-Causes cerebral edema
-found in Assault, Vengence, Trounce
-Toxic Dose
Dog: 4.7 mg/kg
Cats: 1.8 mg/kg
Clinical signs (>24 h after ingestion of high dose; 1-5 d--low dose)
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–
•
Excitement, tremors, seizures
Depression, ataxia
Rx (will take 2-3 wk to know if animal will survive)
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Purge GI tract if exposure recent
Reduce cerebral edema with Mannitol and glucocorticoids
Seizure control with Diazepam and Phenobarbital
Toxicologic Emergencies
• Specific toxicities
– Acetaminophen
• Common OTC drug for analgesia
• Toxic dose: Dog—160-600 mg/kg
Cat—50-60 mg/kg (2 doses in 24 h is almost always
fatal)
• Clinical signs (starts within 1-2 h of ingestion)
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Vomiting, salivation
Facial and paw edema
Depression
Dyspnea
Pale mm
Cyanosis due to methemoglobinemia
• Px—poor
• Rx
– Induce vom/activated charcoal
– Antidote: N-Acetylcysteine (loading dose of140-280 mg/kg PO, IV, then
at 70 mg/kg PO, IV QID x 2-3 d
Toxicologic Emergencies
• Specific toxicities
– Metals
• Lead toxicity more common in dogs than cats
– Source
» Lead paint (prior to 1970’s) is primary source
» Batteries, linoleum, plumbing supplies, ceramic containers,
lead pipes, fishing sinkers, shotgun pellets
– Clinical signs (Usually involves signs of GI and nervous systems)
» Anorexia
» Vom/dir
» Abd pain
-CNS signs do not show initially
» Blindness, seizures, ataxia, tremors, unusual behavior
Toxicologic Emergencies
• Specific toxicities
– Metals
• Lead toxicity
– Dx
»
»
– Rx
»
»
Large # nucleated RBC’s; basophilic stipling
Blood lead conc >35 μg/ml
Remove lead from GI tract (cathartic, Sx)
Chelators (to bind the Pb in blood stream and hasten its
removal)
-Calcium EDTA (ethylene diamine tetra acetic acid)
-Penicillamine
» IV fluids for dehydration and to speed removal via kidneys
» Diazepam, Phenobarbital to control seizures
Toxicologic Emergencies
• Specific toxicities
– Metals
• Zinc Toxicosis
– Usually from ingested pennies, galvanized metal, zinc oxide
ointment
• Clinical signs
– Vomiting
– CNS depression
– Lethargy
• Dx
– Hx of exposure
– Clinical signs
• Rx
– Remove metal objects endoscopically or surgically
– IV fluid therapy
– Ca EDTA chelation
Toxicologic Emergencies
Toxicologic Emergencies
• Specific toxicities
– Ethylene Glycol (antifreeze; sweet taste)
• Lethal dose: Cat—1.5 ml/kg
Dog—6.6 ml/kg
• Signs (onset within 12 h of ingestion)
–
–
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CNS depression, ataxia (may appear intoxicated)
Vomiting
PD/PU
Seizures, coma, death
• Dx
– Hx, signs
– Ethylene Glycol Poison Test—an 8 min test used in cats and dogs
• Rx
– Emesis, adsorbents if ingestion within 3 h of presentation
– IV fluids, NaBicarb for acidosis
– Ethanol inhibits ethylene glycol metabolism (keep animal drunk)
» Dogs (Cats): 20% ethanol—5.5 (5.0) ml/kg q6h x 5, then q8h x 4
– 4-methylpyrazole has been shown to be effective
Toxicologic Emergencies
• Specific toxicities
– Snail Bait (Metaldehyde, methiocarb)
– Metaldehyde mechanism unknown
– Methiocarb is a carbamate and parasympathomimetic
• Signs
–
–
–
–
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Hypersalivation
Incoordination
Muscle fasciculations
Hyperesthesia
Tachycardia
Seizures
• Rx
– Emesis and absorbents
– Pentobarbital, muscle relaxants to control CNS hyperactivity
Toxicologic Emergencies
• Specific toxicities
– Garbage Toxicity
– Common in dogs; not in cats
– Enterotoxin-producing bacteria include Strep, Salmonella, Bacillus
• Signs (within min to h after ingestion)
–
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Anorexia, lethargy
Vom/dia
Ataxia, tremors
Enterotoxic shock can cause death
• Rx
–
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IV Fluid therapy
Broad-spec antibiotics
Intestinal protectants
Muscle relaxers or Valium may be needed to control tremors
Corticosteroids to counter endotoxic shock
Toxicologic Emergencies
• Specific toxicities
– Insecticides
• Pyrethrins and Pyrethroids
– Common ingredients of flea/tick sprays, dips, shampoos, etc
– If used according to instructions, toxicity rarely occurs; if
overused, toxicity can result
• Signs
–
–
–
–
Hypersalivation
Vom/dia
Tremors, hyperexcitability or lethargy
Later, dyspnea, tremors, seizures can occur
• Rx
–
–
–
–
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Bathe animal to remove excess
Induce vomiting/charcoal/cathartics for ingestion
Diazepam may be necessary for mild tremors
Methocarbamol, a muscle relaxer, for moderate-severe tremors
Atropine for hypersalivation and bradycardia
Toxicologic Emergencies
• Specific toxicities
– Insecticides
• Organophosphates and Carbamates
– Inhibit cholinesterase activity (break down of Ach is inhibited)
– Highly fat-soluble; easily absorbed from skin and GI tract
– Found in dips, sprays, dusts, etc for fleas and ticks
• Signs
– Salivation
– Vom/dia
– Muscle twitching
– Miosis
-May progress to
– Seizures, coma, resp depression, death
• Rx
–
–
–
–
Bathe animal
Charcoal if ingested
Atropine (0.2-0.4 mg/kg; half IV, half IM or SQ)
Praloxime chloride (20 mg/kg BID till signs subside)—reactivates
cholinesterase
Toxicologic Emergencies
• Specific toxicities
– Plant Toxicity
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Most common in confined and juvenile animals
Usually from ornamental, indoor plants
Severity varies with plants
ID scientific plant name (florist, greenhouse)
• Araceae family (most from this family)
– Dumb cane, split-leaf philodendron
– Contain calcium oxalate crystals and histamine releasers
• Signs
– Hypersalivation, oral mucosal edema, local pruritis
-Large amount of plant may cause:
– Vomiting, dysphagia, dyspnea, abd pain, vocalization, hemorrhage
• Rx
– Rinse mouth with milk or water to remove Ca Oxalate crystals
– GI decontamination (protectants) may be needed
Dumb Cane (Dieffenbachia)
• aka Mother-in-law’s tongue
• Oral irritation; intense
burning, excess salivation
Sago Palm
• Coagulopathy
• Liver failure
Split Leaf Philodendron
• Oxalate crystals like Dieffenbachia
• Oral irritation; intense burning, excess salivation
Lily of the Valley
• Contains cardiac glucosides
• Cardiac arrythmias, death
Azalea (Rhododendron)
• Hypotension, cardiovascular collapse, death
Toxicologic Emergencies
• Phone advice to give owners (legal issues)
– Protect yourself from exposure before handling animal
• Gloves, protective clothing
– Protect yourself from animal because poisoned animals may
act strangely
– Protect animal from further exposure by removing pet from
source
– Bring sample of vomit, feces, urine
– Bring container/package that toxin was in and a sample of
the toxin (plant material, rat bait, etc)