The Sonographer Attachment Programme At USA Report : Mayo Clinic Rochester = Dobutamine Stress Echo=

5.9 Mayo Clinic Stress Echo Lab Gonda 5:

      Protocol For Dobutamine Stress Echo (DSE)

Procedure

• Dobutamine Stress echo is a procedure that utilizes medication to increase myocardial oxygen demands and cardiac ultrasound images to evaluate systolic dysfunction. Dobutamine stress echo is chosen as an alternative to exercise stress procedure due to the patient’s inability to reach his maximal exercise capacity.

• Inclusion Criteria For Dobutamine Stress Echocardiography

§  Patient NPO for 3 hours prior to test.

§  RN to established intravenous  access if not already present.

• Indication

§  Known coronary artery disease.

§  Suspected coronary artery disease.

§  Evaluate degree of valvular stenosis.

§  Evaluate degree of obstruction.

• Equipment

§  Digital ultrasound unit with integrated stress echo.

§  Stress monitoring equipment.

§  Echo supplies (Electrodes, Ultrasound, Contrast).

§  IV kit.

§  Infusion Pump.

§  Emergency medical equipment.

• Staff

§  Physician.

§  Echo Technologist.

§  Treadmill/Monitoring Technologist.

§  Registered Nurse.

• Medication/Contrast

 IV solution (10cc Dobutamine mixed with 40cc saline in a 60 cc syringe 

administered through a Graseby pump).

§  Beta blockers.

§  Atropine sulfate.

§  Nitroglycerin.

§  Definity.

• Vital Sign Monitoring

Continue 3 Channel ECG monitoring during stress test.

Vital sign recorded at baseline, at every stage during the stress test, every 3 minutes during  recovery and PRN.

12 Lead ECG printed every 1 minutes during stress test and every 3 minutes during recovery.

• Guidelines for administering Dobutamine

§  Based on patient weight

§  Dobutamine 250mg/250ml (1000/mcg/ml)

§  Dobutamine will be administered in stages

§  Stages 1 - 5mcg/kg/min for 3 minutes (for viability)

§  Stages 2 - 10mcg/kg/min for 3 minutes

§  Stages 3 - 20mcg/kg/min for 3 minutes

§  Stages 4 - 30mcg/kg/min for 3 minutes

§  Stages 5 - 40mcg/kg/min for 3 minutes

§  Atropine is given when indicated by monitoring physician

• Guidelines for administering Atropine

§  Atropine 0.25 mg IV given every minutes to a maximum total dose of 2 mg if either of the following condition exist.

§  If THR (defined as 85% of Maximum Heart Rate) has not been achieved at the end of the 30 mcg/kg/min Dobutamine stage.

§  If the heart rate is less than 90 bpm at the end of the 20 mcg/kg/min Dobutamine stage.

• Imaging Guidelines

§  Digitized images captured at baseline,low dose (10 mcg/kg/min Dobutamine) pre peak (10/15 beats below target heart rate) and peak stress images are video taped through the stress test and during recovery.

• Termination Of Procedure

Achievement of greater than or equal to 85% of age predicted maximal heart rate (peak stress).

Maximum Dobutamnie And Atropine doses administered.

SBP less than 90 mmHg, if patient symptomatic, diaphoresis, light headedness, nausea, vomiting.

Development of new, moderate regional wall motion abnormalities.

Serious arrhythmias ie Sustained VT or increasing polymorphic PVC’s, A Fib uncontrolled, 2^nd & 3^rd degree AV blocks

Unusual or severe dyspnea

Signs of poor perfusion, ie pallor, cyanosis

Patient inability to continue

• Recovery Period

Monitor patient until echocardiogram images return to baseline HR returns to within 20 beats Resting Heart Rate, ECG changes return to baseline and patient is asymptmatic.

Oxygen 2 liter per minute per nasal cannula for unresolved ischemia, arrhythmia, or intolerable symptoms to the patients.

NTG tablet 0.4 mg sublingual if patient has chest pain. May repeat every 5 minutes up to a total of 3 doses. Notify echo lab physician if symptom persist, Systolic BP must be greater than 90 mmHg.

Metoprolol 5 mg IV push over 2 minutes, every 5 minutes, up to 3 doses for symptomatic stress induced tachycardia. If patient has history of asthma or bronchospasm, or an ultra short acting beta blocker is indicated for more immediate anti ischemic.

Esmolol 500 mcg/kg initially, followed by 250 mcg/kg/min until symptoms relieved, or to a maximum of 1000 mcg/kg. Notify echo lab physician if symptoms persist.

0.9% Sodium Chloride, 250 ml infuse rapidly for symptomatic hypotension or systolic blood pressure less than 90 mmHg. Assess patient. If Systolic BP are true to be below 90 mmHg. Notify echo lab physician.