Patient Care Radiology

Patient Care

Radiology

Donna Lesniak, RN, CCRC Cardiovascular Imaging Laboratory

Mallinckrodt Institute of Radiology Washington University School of Medicine,

St. Louis, MO

Cardiac Imaging

Modalities

ƒ

Computed Tomography Angiography (CTA)

ƒ

Magnetic Resonance Imaging (MRI)

ƒ

Positron Emission Tomography (PET)

ƒ

Single Photon Emission Computed

Tomography

(SPECT)

ƒ

Stress Echocardiography

Nurse/Coordinator

Responsibilities

TEAMWORK-TEAMWORK-TEAMWORK ƒ Patient care ƒ Safety issues

ƒ Licensed BLS and ACLS

ƒ Regulations for Research

ƒ Good Clinical Practices (GCP)

ƒ Budget

ƒ IND applications

ƒ IRB knowledge, writing consent forms, conducting annual reviews.

ƒ Organizations (ACRP and SOCRA)-examination available after 2 years experience

Nurse/Coordinator

Responsibilities

ƒ

Technical

ƒ Computer skills-Microsoft word, Power Point and Excel

ƒ Database development and maintenance

ƒ Purchasing and maintaining supplies for the lab

ƒ Protocol review and writing protocol worksheets

ƒ Calibrating devices, stocking crash cart and synchronizing all clocks(scanner, monitoring device, EKG)

ƒ Billing codes

Screening

ƒ

Chart review

ƒContraindications for imaging and/or drugs

ƒInclusion/Exclusion

ƒ

Phone interview

ƒConsent process

ƒImaging safety checklist

ƒMedical history

Scheduling

Nurses/Coordinators

ƒ Good communication with scheduling center

ƒ Know correct billing codes for scan

ƒ Balance time slots between physicians

ƒ Cancel time slot if not needed

ƒ Keep an organized calendar for different cases

ƒ Call patient the day prior to confirm appointment

Patients/Participants

ƒ Detailed instructions on preparation of the imaging being scheduled

ƒ Directions to Imaging Center

ƒ Contact information if the patient has any questions

CTA Research

Experience

Total: 255

(64 slice) 2005-2007

ƒ 108 participants enrolled in a PI initiated CTA pilot study

ƒ 26 participants enrolled in a phase II sponsored CTA study

ƒ 46 participants enrolled in a PI initiated CTA and PET study

ƒ 56 participants enrolled in a PI initiated CTA vs. Echo study

(dual source) 2007-2009

ƒ 19 participants enrolled in a PI initiated CTA and heart failure study

CTA Safety

ƒ

Radiation exposure

ƒ

Administration of (IV) contrast media

ƒ

Administration of ß-blocker and

nitroglycerine

CT Safety-Radiation Exposure

ƒALARA

ƒPhysician familiar with various technical parameters of the exam that affect radiation dosage

ƒ milliampere-seconds (mAs)

ƒ peak voltage settings (kVp)

ƒ scan pitch

ƒAutomated x-ray dose shaping algorithms and x-ray tube pulsing applied to minimize exposure (while allowing diagnostic image quality)

CT Safety-Contrast

media

Contrast reactions occurring in approximately 2% of patients are considered mild reactions

ƒ skin hives/rash

ƒ minimal throat tightening

™Prior contrast reactions-oral steroids given beforehand

(some institutions give steroids and benadryl)

™Contrast reaction treatment-observe for a period of time (approx. 30 min.) If no improvement or severe…

Admin. Benadryl 50mg.

CT Safety-Contrast

media

ƒContrast induced bronchospasm

ƒ Mild: Treatment includes oxygen 10-12L by face mask, close observation, and/or 2 puffs of an albuterol or metaproterenol inhaler.

ƒ Moderate: without hypotension: Treatment is as above, with 1:1000, 0.1-0.3 mL given subcutaneously, repeated every 10-15 min. as needed until 1 mL is administered.

ƒ Severe: Administer epinephrine 1:10,000 1 mL slow IV injection over approximately 5 min., repeated every 5-10 min. as needed.

ƒ Contrast induced bronchospasm

ƒMild to moderate: Treatment includes oxygen 10-12 L by face mask and epinephrine 1:1000 0.1-0.3 mL given subcutaneously, repeated every 10-15 minutes as needed until 1 mL is administered.

CT Safety-Contrast

media

ƒ

Contrast induced nephropathy

ƒ Creatinine≥1.5mg/dL usually excluded

ƒ Encourage hydration

ƒ Diabetics-Patients taking Glucophage, Glucovance or metformin should hold the medication the day of imaging and for 48hrs. following the procedure.

ƒ

Contrast Extravasation

ƒ A physician should evaluate all extravasations

ƒ Observe in radiology dept. for 2-4 hrs.

ƒ Elevate affected arm above the heart

CT Safety- ß-blocker and

nitrate administration

ƒAdministration

ƒPhysician or nurse trained in administration of cardiac medications

ƒSide effects

ƒHypotension, dizziness, lightheaded, nausea and/or headache

ƒContraindications

ƒHistory of Asthma or COPD (ß-blocker)

ƒCurrent use of Viagra™, Cialis™ or Levitra™-patient needs to hold these medications, 24-72hrs. (Nitrate)

ƒSBP is <100mmHg (both)

CTA Contraindications (64

slice)

ƒ Potential artifacts

ƒElevated calcium score ƒIrregular heart rate ƒTachycardia ƒPoor IV access ƒBMI >35

ƒ Patient safety contraindications

ƒElevated creatinine (≥1.5mg/dL) ƒIV contrast allergy

ƒIodine/shellfish allergies ƒPregnancy or breast feeding

CTA Patient

Preparation

ƒ Consent process and safety checklist

ƒ Check creatinine

ƒ Check HR and BP and monitor during scan

ƒ Start 18-20 gauge IV in the right antecubital vein

ƒ Administer ß-blocker for HR >62 bpm

ƒ Prep skin and attach leads for CTA below clavicle with the arms in the up position

ƒ Remind patient that they will be getting Nitroglycerine during their CTA and the feeling they may experience during the contrast injection

CTA Patient

Monitoring

Several monitoring devices are available for

CTA monitoring.

ƒNIBP ƒO₂ saturation ƒEKG ƒHR ƒTemperature ƒClock

CTA (64 slice) Lopressor

Protocol

HR >62bpm and SBP >100mmHg

ƒ Lopressor 5mg. slow IV push every 5 min. until target HR met

ƒ Max dose 35mg.

ƒ Practice breathholds

ƒ HR may drop during breathholds, but may increase upon the administration of IV contrast

ƒ ß-blockers do not have same effect on diabetics

CTA-Nitroglycerine

Protocol

ƒ

Immediately prior to performing CTA,

sublingual nitroglycerine 0.4mg. is given to

enhance visualization of coronary arteries

ƒ

HR and BP will be continuously measured

prior to and throughout the scan.

MRI Research

Experience

Total = 454 (1999-2009) 166 Stress MRI’s

ƒ 239 Participants enrolled in various research MRI’s as part of an MRI course (121 no contrast, 74 contrast and 44 contrast and Adenosine)

ƒ 55 Participants enrolled in a Phase II sponsored MRI study

ƒ 17 Participants enrolled in a PI initiated MRI perfusion study with Adenosine

ƒ 24 Participants enrolled in a MRI and attenuation study

ƒ 14 Participants enrolled in a PI initiated MRI and LAAT study

ƒ 89 Participants enrolled in 3 PI initiated rest and stress with Dobutamine MRI and PET studies

ƒ 5 Participants enrolled in an ongoing PI initiated MRI vs. SPECT study using regadenoson

ƒ 11 Participants received a perfusion MRI with adenosine in a clinical setting

MRI Safety

Magnetic memory of credit cards and

badges, as well as magnetic devices

such as watches, phones, beepers

and tapes can be damaged by MRI

magnets. Patients and non MRI

personnel need to be informed each

and every time to leave them outside

the magnet room.

MRI Scanner Safety

This incident happened at our facility when a janitorial worker thought the magnet was

off since the lights were out for the evening.

THE MAGNET IS NEVER OFF

The magnet had to be shut down for the removal of the waxer.

MRI Patient and Scanner

Safety

Unfortunately, the IV pole in the middle was my mistake. Even after years of experience around the magnet. I walked a patient into the magnet with an IV pole. Currently we have added to our equipment an MRI compatible IV pole and pump by Medrad.

MRI Safety with

Contrast

NSF/NFD…what is it?

ƒ NSF- Nephrogenic systemic fibrosis

ƒ NFD- Nephrogenic fibrosing dermopathy

ƒ Systemic disorder - most prominent and visible effects in the skin

ƒ Occurs only in patients with kidney disease

ƒ No cases identified prior to 1997

ƒ No convincing evidence that NSF is caused by

ƒMedication ƒMicroorganism ƒDialysis

MRI - FDA Report on

GBCA

ƒ FDA ALERT [6/2006, updated 12/2006 and 5/23/2007]: This updated Alert highlights FDA’s request for addition of a boxed warning and new warnings about risk of nephrogenic systemic fibrosis (NSF) to the full prescribing information for all gadolinium-based contrast agents (GBCAs) (Magnevist, MultiHance, Omniscan, OptiMARK, ProHance). This new labeling highlights and describes the risk for NSF following exposure to a GBCA in patients with acute or chronic severe renal insufficiency (a glomerular filtration rate <30 mL/min/1.73m2_{) and patients with}

acute renal insufficiency of any severity due to the hepato-renal syndrome or in the peri-operative liver transplantation period. In these patients, avoid the use of a GBCA unless the diagnostic information is essential and not available with non-contrast enhanced magnetic resonance imaging. NSF may result in fatal or debilitating systemic fibrosis.

ƒ A GFR calculator can be found on the National Kidney Foundation

website.

ƒ Current updates can be found on the ISMRM website.

MRI

Contraindications

ƒ Pacemakers, shrapnel, brain aneurysm clips or other implanted devices

ƒ Claustophobia

ƒ Excessive abdominal girth ƒ Pregnancy (1st_trimester)

ƒ Hemodynamic instability or critical illness

MRI Contraindications

with Contrast

ƒ History of contrast allergy

ƒ History of renal insufficiency (GFR <30 mL/min/1.73 m2₎

ƒ Pregnancy/Breastfeeding

™Current updates can be found on the MRI safety website. www.mrisafety.com

MRI Patient

Preparation

ƒ Consent process and safety checklist

ƒ Patient removes jewelry and changes into a gown/scrubs

ƒ Check creatinine (unless pt. had it checked within 30 days)

ƒ Check HR and BP

ƒ Start 18-20ga. IV in an antecubital vein (for perfusion studies start a second IV)

ƒ Have patient use the restroom prior to going into the scanner

ƒ Prep skin and attach leads to patient (Currently, we’re using fiberoptics and wireless for gating, depending on the scanner.)

MRI Monitoring

Several monitoring devices are available

for MRI monitoring.

ƒNIBP ƒO₂ saturation ƒEKG ƒHR ƒTemperature ƒClock

™

MRI compatibility is most

important

MRI: Pharmacological Stress

Testing

ƒ The stress chemical agents usually used in the cardiac MRI setting are dobutamine, adenosine and regadenoson.

ƒ Adenosine and regadenoson are vasodilators that are extremely short acting and easier to use.

ƒ Dobutamine is an inotropic vasopressor that requires incremental increases in doses, therefore taking a longer time to stress the heart.

™Cardiac MR perfusion exams as of Jan. 2008 have their own CPT code 75563 which is reimbursed by CMS for appropriate indications.

Adenosine/Regadenoson

Hemodynamics

ƒ

They produce negative chronotropic,

dromotropic and inotropic (rate, velocity,

force) effect on the cardiac muscle fibers and

nerves.

ƒ

Net effect is a mild to moderate decrease in

systolic, diastolic and mean arterial blood

pressure associated with a reflex increase in

heart rate.

ƒ

Rarely significant hypotension or tachycardia

have been observed.

Adenosine

Phamacokinetics

ƒ

Rapidly cleared from the circulation by

cellular uptake. It is degraded by the cell.

ƒ

Half life of <10sec. makes this a great drug

in the clinical setting.

ƒ

Requires no hepatic or renal function for

activation.

ƒ

Renal or hepatic failure does not alter its

effectiveness or tolerability.

Perfusion Stress

Indications

Alternative to exercise stress testing for:

ƒ Patients with Angina Pectoris

ƒ Risk stratification

ƒ Surgical clearance

ƒ Post MI and coronary revascularization procedures

ƒ Patients with risk factors for CAD or atypical chest pain

When exercise stress is not possible or desirable:

ƒ Patients unable to perform treadmill exercise

ƒ Patients with LBBB

ƒ Paced rhythm

ƒ Concomitant treatment with meds that blunt the heart rate response (beta blockers and calcium channel blockers)

Perfusion Stress

Contraindications

ƒ

Second or third degree atrial ventricular

node block

ƒ

Sinus node disease, such as sick sinus

syndrome or symptomatic bradycardia

ƒ

Known or suspected bronchoconstrictive or

bronchospastic lung disease (COPD per se

is not a contraindication)

ƒ

Known sensitivity to adenosine

ƒ

Systolic BP<90mm Hg.

ƒ

Severe sinus bradycardia (<40/min) is a

relative contraindication

Adenosine Adverse

Reactions >1%

ƒ

Flushing

44%

ƒ

Chest discomfort

40%

ƒ

Dyspnea or urge to breath deeply

28%

ƒ

Headache

18%

ƒ

Throat, neck or jaw discomfort

15%

ƒ

Gastrointestinal discomfort

13%

ƒ

Lightheadedness

Adenosine Adverse

Reactions <1%

ƒ Back discomfort, lower extremity discomfort, weakness, drowsiness, emotional instability, tremors

ƒ Non-fatal MI, life threatening ventricular arrhythmias, third degree AV block bradycardia, palpitations, sinus exit block, sinus pause, T-wave changes, hypertension (systolic BP >200)

ƒ Genital urinary urgency

ƒ Cough, blurred vision, dry mouth, ear discomfort, metallic taste, nasal congestion, tongue discomfort, scotomas

Adenosine Dosage and

Administration

ƒAdenosine should be administered through a peripheral vein by continuous infusion over 4 minutes in a separate line from the contrast.

ƒThe dose for adults is 140ug/kg/min.

ƒInfusion rate = 0.140(mg/kg/min) x body wt.(kg) (ml/min) Adenosine concentration (3mg/ml)

ƒAdenoscan* available in 20 or 30ml vials, 3mg/ml

Lexiscan (regadenoson)

is given as a

single bolus dose of 0.4mg/5mL

Stress Perfusion Patient Preparation

1

ƒ Restriction of Xanthine containing products 24-36 hours before test. (Tea, coffee, Uniphyl, Theo-Dur, Slo-Bid, Theophylline etc.) Theophylline is the antidote for Adenosine.

ƒ Nothing to eat or drink at least 6, however best if 8 hrs. before test

ƒ No caffeine or chocolate at least 6, however best if 24 hrs. before test.

ƒ No smoking, use of pipe or snuff for 4 hrs. before test

ƒ Any prior studies with results should be available and reviewed by clinician.

ƒ Cardiac enzymes (CK, CKmb, Troponin) reviewed only in case of angina symptoms.

ƒ Prior 12 lead EKG available and reviewed.

Adenosine Stress Patient

Preparation 2

ƒ Test should be explained and informed consent given by patient.

ƒ Chest preparation, EKG electrode placement

ƒ IV access should be obtained with a large bore catheter no small than a #18gauge.

ƒ Baseline EKG, BP, HR and pulse oximetry

ƒ IV sedation prn. (Versed 1mg. IVP)

ƒ With IV sedation -O2via nasal cannula at 2L/min.

Adenosine Infusion

Monitoring

ƒ Patient is remotely monitored for NIBP, O2saturation,

HR, EKG and adverse reactions.

ƒ Stop infusion if wheezing starts to develop. Half-life of adenosine is <10 seconds.

ƒ Most episodes of AV block are asymptomatic, transient, and do not require intervention; less than 7% require

termination of adenosine infusion, which is done if the patient becomes symptomatic from AV block.

Adenosine Infusion EKG

Changes

ƒ Tachycardia/bradycardia

ƒ ST depression. Stop infusion if severe chest pain is associated with ≥2mm ST depression. ST depression alone does not require stopping infusion.

ƒ Heart block-1, 2, 3 Stop infusion of adenosine, if patient develops symptomatic persistent second degree or complete heart block. If

asymptomatic, infusion can continue.

ƒ PVC’s

ƒ T wave inversion

ƒ Sinus pause (rare)

Methods for Administration of

Adenosine and Dobutamine in the

MRI Suite

Historically, the patient would either be removed from the medication, remain connected to a non-MR compatible infusion pump outside the scanner room with up to 30 feet of tubing, or be disqualified from MR imaging altogether. The newer systems help to enable scanning of patients who could most benefit from MR imaging regardless of their need for infusion therapy.

MRI compatible infusion pumps:

ƒ Continuum MR Compatible Infusion System by Medrad, Inc.

ƒ MRidium(TM) MRI Infusion Pump by Iradimed, Inc. marketed by Covidien

What is Dobutamine?

ƒ Dobutamine is a synthetic chemical with primarily beta 1 adrenergic activity (rocket fuel for the heart).

ƒ Here it is used as an agent to increase heart rate.

ƒ Dobutamine is supplied as Dobutamine HCl a synthetic inotropic agent related structurally to dopamine. It occurs as white, to off-white, crystalline powder with a pKa of 9.4. Dobutamine is sparingly soluble in water and alcohol

Dobutamine Pharmacology

ƒ It is an inotropic vasopressor. It increases myocardial contractility, blood pressure, cardiac index and output, blood flow, oxygen delivery and oxygen consumption.

ƒ It is metabolized in the liver to an inactive compound.

ƒ The onset of action is 1-2 minutes after IV administration with the peak effect occuring in 10 minutes.

Dobutamine

Hemodynamics

ƒ

Blood pressure and cardiac rate generally

are unaltered or slightly increased

because of increased cardiac output.

ƒ

Increased myocardial contractility may

increase myocardial oxygen demand and

coronary blood flow.

Dobutamine Indications

Alternative to exercise stress testing for:

ƒ Patients with asthma

ƒ Patients with angina pectoris

ƒ Risk stratification

ƒ Surgical clearance

ƒ Post MI and coronary revascularization procedures

ƒ Patients with risk factors for CAD and atypical chest pain

When exercise stress not possible or desirable:

ƒ Patients unable to perform treadmill exercise

ƒ Patients with LBBB

Dobutamine

Contraindications

ƒ Known hypersensitivity to the drug

ƒ Patients with a history of ventricular ectopy, and poor LV function should be considered for a adenosine study

ƒ Patients with atrial fibrillation or other dysrhythmia should have a well controlled ventricular rate

ƒ CV medications, especially beta blockers should be restricted if possible

ƒ Unstable angina

ƒ Uncontrolled hypertension (≥200/115mmHg)

ƒ Valvular heart disease (critical aortic stenosis, IHSS, MR) are absolute

ƒ Hemodynamically significant LV outflow tract obstruction

Dobutamine Dosage and

Administration

ƒ Dobutamine should be administered through a peripheral vein by continuous infusion.

ƒ Start infusing at a rate of 10ug/kg/min, increasing the dose by 10ug/kg increments every 3min. until 40ug/kg/min or 85% of AAMHR is achieved. Close monitoring of patient is critical since Dobutamine will produce myocardial ischemia at higher doses. ƒ Cine imaging will be acquired at the end of each 3

min. interval.

ƒ After stress, measure BP and monitor EKG until HR and BP are within normal limits.

Dobutamine Stress End

Points

ƒ

Secondary end points include severe angina,

prolonged run of non sustained VT, VF, SVT

with rapid ventricular rate, severe side effects

leading to patient refusal to continue.

ƒ

Usually side effects resolve with

discontinuation of infusion, however, if they

don’t a bolus of a short acting beta

blocker(metoprolol from 1-5mg) may be

administered.

Dobutamine Stress Patient

Preparation

ƒ

Beta blocker should be held for 24hrs

before the test.

ƒ

Preparation is very similar to adenosine

stress except that patients may have

xanthine (caffeine).

Dobutamine Adverse

Reactions

ƒ

Severe ventricular arrhythmias

ƒ

Minor side effects include:

ƒFlushing

ƒFacial tingling

ƒDyspnea

ƒHeadache

ƒChest pain

Arrhythmias occur 15% of the time and generally resolve spontaneously.

Dobutamine Infusion

Monitoring

ƒ

Patient is remotely monitored for NIBP, O

₂

saturation, HR, EKG and adverse

reactions.

ƒ

Management of most minor side effects

includes discontinuation of infusion.

ƒ

Severe ischemia can be managed with

NTG and beta blockers.

Dobutamine Treatment for

Signs and Symptoms

ƒ

Often stopping the dobutamine infusion is

all that is necessary.

ƒ

Severe side effects may require IV

administration of a short acting

beta-blocker.

ƒ

IV metoprolol, 1-5mg used to reverse the

effects of dobutamine if these did not

revert quickly.

Donna Lesniak, RN, CCRC Cardiovascular Imaging Laboratory

314-747-3875 cassadyd@mir.wustl.edu