Patient Care Radiology

Transcription

1 Patient Care Radiology Cardiac Imaging Modalities Computed Tomography Angiography (CTA) Magnetic Resonance Imaging (MRI) Positron Emission Tomography (PET) Donna Lesniak, RN, CCRC Cardiovascular Imaging Laboratory Mallinckrodt Institute of Radiology Washington University School of Medicine, St. Louis, MO Single Photon Emission Computed Tomography (SPECT) Stress Echocardiography Nurse/Coordinator Responsibilities TEAMWORK-TEAMWORK-TEAMWORK Patient care Safety issues Licensed BLS and ACLS Regulations for Research Good Clinical Practices (GCP) Budget IND applications IRB knowledge, writing consent forms, conducting annual reviews. Organizations (ACRP and SOCRA)-examination available after 2 years experience Nurse/Coordinator Responsibilities Technical Computer skills-microsoft word, Power Point and Excel Database development and maintenance Purchasing and maintaining supplies for the lab Protocol review and writing protocol worksheets Calibrating devices, stocking crash cart and synchronizing all clocks(scanner, monitoring device, EKG) Billing codes Screening Chart review Contraindications for imaging and/or drugs Inclusion/Exclusion Phone interview Consent process Imaging safety checklist Medical history Scheduling Nurses/Coordinators Good communication with scheduling center Know correct billing codes for scan Balance time slots between physicians Cancel time slot if not needed Keep an organized calendar for different cases Call patient the day prior to confirm appointment Patients/Participants Detailed instructions on preparation of the imaging being scheduled Directions to Imaging Center Contact information if the patient has any questions

2 CTA Research Experience Total: 255 (64 slice) participants enrolled in a PI initiated CTA pilot 26 participants enrolled in a phase II sponsored CTA 46 participants enrolled in a PI initiated CTA and PET 56 participants enrolled in a PI initiated CTA vs. Echo (dual source) participants enrolled in a PI initiated CTA and heart failure CTA Safety Radiation exposure Administration of (IV) contrast media Administration of ß-blocker and nitroglycerine CT Safety-Radiation Exposure ALARA Physician familiar with various technical parameters of the exam that affect radiation dosage milliampere-seconds (mas) peak voltage settings (kvp) scan pitch Automated 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 skin hives/rash 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 Contrast induced bronchospasm Mild: Treatment includes oxygen 10-12L by face mask, close observation, and/or 2 puffs of an albuterol or metaproterenol inhaler. Moderate: without hypotension: Treatment is as above, with 1:1000, ml given subcutaneously, repeated every min. as needed until 1 ml is administered. Severe: Administer epinephrine 1:10,000 1 ml slow IV injection over approximately 5 min., repeated every 5-10 min. as needed. Contrast induced bronchospasm Mild to moderate: Treatment includes oxygen L by face mask and epinephrine 1: ml given subcutaneously, repeated every minutes as needed until 1 ml is administered. CT Safety-Contrast media Contrast induced nephropathy Creatinine 1.5mg/dL usually excluded Encourage hydration Diabetics-Patients taking Glucophage, Glucovance or metformin should hold the medication the day of imaging and for 48hrs. following the procedure. Contrast Extravasation A physician should evaluate all extravasations Observe in radiology dept. for 2-4 hrs. Elevate affected arm above the heart Cool dry packs applied to the site

3 CT Safety- ß-blocker and nitrate administration Administration Physician or nurse trained in administration of cardiac medications Side effects Hypotension, dizziness, lightheaded, nausea and/or headache Contraindications History of Asthma or COPD (ß-blocker) Current use of Viagra, Cialis or Levitra patient needs to hold these medications, 24-72hrs. (Nitrate) SBP is <100mmHg (both) CTA Contraindications (64 slice) Potential artifacts Elevated calcium score Irregular heart rate Tachycardia Poor IV access BMI >35 Patient safety contraindications Elevated creatinine ( 1.5mg/dL) IV contrast allergy Iodine/shellfish allergies Pregnancy or breast feeding CTA Patient Preparation Consent process and safety checklist Check creatinine Check HR and BP and monitor during scan Start gauge IV in the right antecubital vein Administer ß-blocker for HR >62 bpm Prep skin and attach leads for CTA below clavicle with the arms in the up position 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. NIBP O 2 saturation EKG HR Temperature Clock CTA (64 slice) Lopressor Protocol HR >62bpm and SBP >100mmHg Lopressor 5mg. slow IV push every 5 min. until target HR met Max dose 35mg. Practice breathholds HR may drop during breathholds, but may increase upon the administration of IV contrast ß-blockers do not have same effect on diabetics CTA-Nitroglycerine Protocol Immediately prior to performing CTA, sublingual nitroglycerine 0.4mg. is given to enhance visualization of coronary arteries HR and BP will be continuously measured prior to and throughout the scan.

4 MRI Research Experience Total = 454 ( ) 166 Stress MRI s 239 Participants enrolled in various research MRI s as part of an MRI course (121 no contrast, 74 contrast and 44 contrast and Adenosine) 55 Participants enrolled in a Phase II sponsored MRI 17 Participants enrolled in a PI initiated MRI perfusion with Adenosine 24 Participants enrolled in a MRI and attenuation 14 Participants enrolled in a PI initiated MRI and LAAT 89 Participants enrolled in 3 PI initiated rest and stress with Dobutamine MRI and PET studies 5 Participants enrolled in an ongoing PI initiated MRI vs. SPECT using regadenoson 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? NSF- Nephrogenic systemic fibrosis NFD- Nephrogenic fibrosing dermopathy Systemic disorder - most prominent and visible effects in the skin Occurs only in patients with kidney disease No cases identified prior to 1997 No convincing evidence that NSF is caused by Medication Microorganism Dialysis MRI - FDA Report on GBCA 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 gadoliniumbased 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/1.73m 2 ) 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. A GFR calculator can be found on the National Kidney Foundation website. Current updates can be found on the ISMRM website.

5 MRI Contraindications Pacemakers, shrapnel, brain aneurysm clips or other implanted devices Claustophobia Excessive abdominal girth Pregnancy (1 st trimester) Hemodynamic instability or critical illness MRI Contraindications with Contrast History of contrast allergy History of renal insufficiency (GFR <30 ml/min/1.73 m 2 ) Pregnancy/Breastfeeding Current updates can be found on the MRI safety website. MRI Patient Preparation Consent process and safety checklist Patient removes jewelry and changes into a gown/scrubs Check creatinine (unless pt. had it checked within 30 days) Check HR and BP Start 18-20ga. IV in an antecubital vein (for perfusion studies start a second IV) Have patient use the restroom prior to going into the scanner 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. NIBP O 2 saturation EKG HR Temperature Clock MRI compatibility is most important MRI: Pharmacological Stress Testing The stress chemical agents usually used in the cardiac MRI setting are dobutamine, adenosine and regadenoson. Adenosine and regadenoson are vasodilators that are extremely short acting and easier to use. 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 have their own CPT code which is reimbursed by CMS for appropriate indications. Adenosine/Regadenoson Hemodynamics They produce negative chronotropic, dromotropic and inotropic (rate, velocity, force) effect on the cardiac muscle fibers and nerves. Net effect is a mild to moderate decrease in systolic, diastolic and mean arterial blood pressure associated with a reflex increase in heart rate. Rarely significant hypotension or tachycardia have been observed. Adenosine Phamacokinetics Rapidly cleared from the circulation by cellular uptake. It is degraded by the cell. Half life of <10sec. makes this a great drug in the clinical setting. Requires no hepatic or renal function for activation. Renal or hepatic failure does not alter its effectiveness or tolerability.

6 Perfusion Stress Indications Alternative to exercise stress testing for: Patients with Angina Pectoris Risk stratification Surgical clearance Post MI and coronary revascularization procedures Patients with risk factors for CAD or atypical chest pain When exercise stress is not possible or desirable: Patients unable to perform treadmill exercise Patients with LBBB Paced rhythm Concomitant treatment with meds that blunt the heart rate response (beta blockers and calcium channel blockers) Perfusion Stress Contraindications Second or third degree atrial ventricular node block Sinus node disease, such as sick sinus syndrome or symptomatic bradycardia Known or suspected bronchoconstrictive or bronchospastic lung disease (COPD per se is not a contraindication) Known sensitivity to adenosine Systolic BP<90mm Hg. Severe sinus bradycardia (<40/min) is a relative contraindication Adenosine Adverse Reactions >1% Flushing 44% Chest discomfort 40% Dyspnea or urge to breath deeply 28% Headache 18% Throat, neck or jaw discomfort 15% Gastrointestinal discomfort 13% Lightheadedness Adenosine Adverse Reactions <1% Back discomfort, lower extremity discomfort, weakness, drowsiness, emotional instability, tremors 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) Genital urinary urgency Cough, blurred vision, dry mouth, ear discomfort, metallic taste, nasal congestion, tongue discomfort, scotomas Adenosine Dosage and Administration Adenosine should be administered through a peripheral vein by continuous infusion over 4 minutes in a separate line from the contrast. The dose for adults is 140ug/kg/min. Infusion rate = 0.140(mg/kg/min) x body wt.(kg) (ml/min) Adenosine concentration (3mg/ml) Adenoscan* 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 Restriction of Xanthine containing products hours before test. (Tea, coffee, Uniphyl, Theo-Dur, Slo-Bid, Theophylline etc.) Theophylline is the antidote for Adenosine. Nothing to eat or drink at least 6, however best if 8 hrs. before test No caffeine or chocolate at least 6, however best if 24 hrs. before test. No smoking, use of pipe or snuff for 4 hrs. before test Any prior studies with results should be available and reviewed by clinician. Cardiac enzymes (CK, CKmb, Troponin) reviewed only in case of angina symptoms. Prior 12 lead EKG available and reviewed. Order checked

7 Adenosine Stress Patient Preparation 2 Test should be explained and informed consent given by patient. Chest preparation, EKG electrode placement IV access should be obtained with a large bore catheter no small than a #18gauge. Adenosine Infusion Monitoring Patient is remotely monitored for NIBP, O 2 saturation, HR, EKG and adverse reactions. Stop infusion if wheezing starts to develop. Half-life of adenosine is <10 seconds. Baseline EKG, BP, HR and pulse oximetry IV sedation prn. (Versed 1mg. IVP) With IV sedation -O 2 via nasal cannula at 2L/min. 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 Tachycardia/bradycardia ST depression. Stop infusion if severe chest pain is associated with 2mm ST depression. ST depression alone does not require stopping infusion. 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. PVC s T wave inversion 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: Continuum MR Compatible Infusion System by Medrad, Inc. MRidium(TM) MRI Infusion Pump by Iradimed, Inc. marketed by Covidien What is Dobutamine? Dobutamine is a synthetic chemical with primarily beta 1 adrenergic activity (rocket fuel for the heart). Here it is used as an agent to increase heart rate. 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 It is an inotropic vasopressor. It increases myocardial contractility, blood pressure, cardiac index and output, blood flow, oxygen delivery and oxygen consumption. It is metabolized in the liver to an inactive compound. The onset of action is 1-2 minutes after IV administration with the peak effect occuring in 10 minutes. The half-life of its drug effect is two minutes.

8 Dobutamine Hemodynamics Blood pressure and cardiac rate generally are unaltered or slightly increased because of increased cardiac output. Increased myocardial contractility may increase myocardial oxygen demand and coronary blood flow. Dobutamine Indications Alternative to exercise stress testing for: Patients with asthma Patients with angina pectoris Risk stratification Surgical clearance Post MI and coronary revascularization procedures Patients with risk factors for CAD and atypical chest pain When exercise stress not possible or desirable: Patients unable to perform treadmill exercise Patients with LBBB Dobutamine Contraindications Known hypersensitivity to the drug Patients with a history of ventricular ectopy, and poor LV function should be considered for a adenosine Patients with atrial fibrillation or other dysrhythmia should have a well controlled ventricular rate CV medications, especially beta blockers should be restricted if possible Unstable angina Uncontrolled hypertension ( 200/115mmHg) Valvular heart disease (critical aortic stenosis, IHSS, MR) are absolute Hemodynamically significant LV outflow tract obstruction Dobutamine Dosage and Administration Dobutamine should be administered through a peripheral vein by continuous infusion. 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. Cine imaging will be acquired at the end of each 3 min. interval. After stress, measure BP and monitor EKG until HR and BP are within normal limits. Dobutamine Stress End Points 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. 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 Beta blocker should be held for 24hrs before the test. Preparation is very similar to adenosine stress except that patients may have xanthine (caffeine).

9 Dobutamine Adverse Reactions Severe ventricular arrhythmias Minor side effects include: Flushing Facial tingling Dyspnea Headache Chest pain Arrhythmias occur 15% of the time and generally resolve spontaneously. Dobutamine Infusion Monitoring Patient is remotely monitored for NIBP, O 2 saturation, HR, EKG and adverse reactions. Management of most minor side effects includes discontinuation of infusion. Severe ischemia can be managed with NTG and beta blockers. Dobutamine Treatment for Signs and Symptoms Often stopping the dobutamine infusion is all that is necessary. Severe side effects may require IV administration of a short acting betablocker. IV metoprolol, 1-5mg used to reverse the effects of dobutamine if these did not revert quickly. Donna Lesniak, RN, CCRC Cardiovascular Imaging Laboratory [email protected]