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6/7/14
1
David Liss, BA, RVT, VTS (ECC, SAIM) Los Angeles, CA
david@ervettech.com
We will follow this case from admitting to discharge
Learning principles along the way
6/7/14
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6y MN Doberman Presents on emergency
for trouble breathing On PE:
HR: 160/ weak pulses RR: 70 Cyanotic MM’s Orthopneic posture Collapsed in the lobby 5/6 Systolic murmur Crackles heard on
auscultation
Congestive Heart Failure (CHF) is a syndrome resulting from cardiac disease Valvular disease
MVD, Tricuspid dysplasia
Myocardial disease DCM, HCM
Left/Right Side Failure (LEFT = LUNGS)
Progressive and chronic Incremental changes occur until they lead to
volume overload
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Cardiac Output = WORK of the heart Amount of blood (L) ejected in one minute
L/min HR = MIN Stroke Volume (L)
Preload Afterload Contractility
CARDIAC OUTPUT (L/min)
Heart Rate (min) Stroke Volume (L) components:
Preload: Volume in LV at end diastole
Problems associated: • Tachycardia • Bradycardia
Afterload: force heart must pump against
Contractility: Instrinsic strength of the heart
Low blood volume
Weak/ stretched heart
Ventricle wall
stretches No compensatory
increase in contractility
Release of Renin in kidneys
Converts Angiotensinogen to AgI
Aldosterone retains Na+
ADH retains free water
• Potent Vasoconstrictor • ADH Release • Aldosterone Release
Vasoconstriction
Blood pools SV CO
Angio I Angio II
Angiotensin-Converting Enzyme (ACE)
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Massive fluid retention Capillary blood vessels swell Hydrostatic pressure increases- water leaks Water leaks into interstitium
and eventually alveoli
Heart failure can occur bi-ventricularly RIGHT = BODY LEFT = LUNGS
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1- Doberman 2- Dyspnea/Orthopnea 3- Tachycardia 4- Cyanosis 5- Murmur 6- Crackles
1- Ensure adequate oxygenation 2- Assess cardiac function 3- Provide sedation (if needed) 4- Increase forward flow 5- Assess for arrhythmias
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Initial assessment + airway Airway is clear
Breathing: Tachypneic Orthopneic Dyspneic
Options?
1- Flow-by oxygen 2- Oxygen cage 3- Oxygen hood 4- Nasal oxygen 5- Tracheal catheter 6- Intubation/PPV
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1- Oxygen provided via face mask
2- Large bore IV Catheter placed 16 ga R Cephalic
3- Blood pressure obtained 42 mmHg systolic
4- Stat Thoracic Ultrasound 5- Furosemide bolus
administered
Physical Exam
Radiographs ECG
Echocardiogram
Weak thready pulses Hypoxic Murmur Crackles
Classic findings (LEFT): Perihilar interstitial/alveolar pattern Cardiomegaly Left atrial enlargement
Cats may have pleural effusion (rare in dogs with L sided failure)
Classic findings (RIGHT): Right atrial enlargement Ascites Pleural effusion
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Validated to assess cardiac size Step 1: Measure long axis of heart Step 2: Transfer to cranial edge of T4
Count how many vertebrae fall within lines
Step 3: Measure short axis of the heart Step 4: Transfer to cranial edge of T4
Count how many vertebrae fall within lines
VHS = S + L Canine normal: 8.7-10.7
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Cranial edge T4
Long axis
Short axis
L = 6.1 S = 5.1
S + L = 11.2
Arrhythmias of all sorts Sinus
Tachycardia Supraventricular
Atrial Fibrillation SVT Atrial Tachycardia
Ventricular Ventricular Tachycardia
ATRIAL FIBRILLATION
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Visual inspection of the heart/lungs Cardiac function can be assessed
Atrial/ventricular chamber size Valve function (doppler flow) Abnormal pathology
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1- Diuretics 2- Vasodilators
3- Positive inotropes
4- Anti-arrhythmics
Furosemide is most commonly used/recommended Inhibits Na reabsorption in Loop of Henle If tubular fluid contains more Na+ water will follow
Mobilizes fluid from alveoli/ interstitium and excretes it via urination
Bolus dose: 2-4 mg/kg CRI dose: 0.6-1 mg/kg/hr
Concerns: 1- Additional fluid
may worsen edema 2- Rate could increase
edema Tips: Use D5W and set
rate equal to 1 ml/hr
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1- Sodium Nitroprusside 2- Nitroglycerin Sodium Nitroprusside = VERY short-acting Given as a CRI- only for limited time Both reduce ventricular volume (preload) by
increasing venous capacity
Dobutamine Increases intrinsic contraction of heart Improves forward flow Not long term
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Inodilator (Positive inotrope and vasodilator) Good oral bioavailability Peak effects in one hour Only give if able to
give PO meds
Oral vasodilator (arteriodilator) 1 hour onset of action after PO administration Can be used for refractory heart failure
Digoxin Calcium Channel Blockers Beta blockers
Careful with DCM Don’t want to reduce
rate TOO quickly
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After initial interventions: Started Lasix CRI Dobutamine CRI Weaned off anesthetic
machine- placed in O2 cage
Started Sodium Nitroprusside CRI
Continuous BP monitoring
Patient was noticeably less dyspneic Added Pimobendan and Hydralazine Weaned off Sodium Nitroprusside
Continued in oxygen
Weaned off Lasix CRI Started intermittent injections
Weaned off Dobutamine CRI
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Off of O2 Oral medications + food/water Transferred to Cardiology
Discharged by Cardio Returned with acute forelimb weakness
Sudden acute cardiac arrest in hospital
Questions? david@ervettech.com Join my Facebook group: ER Vet Tech Rounds
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