Chapter 52 - Electrocardiography and pulmonary function testing. This chapter introduces you to the electrocardiograph instrument and how to administer an electrocardiogram. You will also learn how to apply electrocardiograph electrodes and wires, operate the instrument, and troubleshoot problems that can occur while recording the heart''s electrical activity.
CHAPTER 52 Electrocardiography and Pulmonary Function Testing © 2011 The McGraw-Hill Companies, Inc All rights reserved 522 Learning Outcomes 52.1 Describe the anatomy and physiology of the heart 52.2 Explain the conduction system of the heart 52.3 Describe the basic patterns of an electrocardiogram (ECG) 52.4 Identify the components of an electrocardiograph and what each does © 2011 The McGraw-Hill Companies, Inc All rights reserved 523 Learning Outcomes (cont.) 52.5 Explain how to position the limb and precordial electrodes correctly 52.6 Describe in detail how to obtain an ECG 52.7 Identify the various types of artifacts and potential equipment problems and how to correct them © 2011 The McGraw-Hill Companies, Inc All rights reserved 524 Learning Outcomes (cont.) 52.8 Identify how the ECG is interpreted 52.9 Identify common arrhythmias 52.10 Summarize exercise electrocardiography 52.11 Explain the procedure of Holter monitoring 52.12 Describe forced vital capacity © 2011 The McGraw-Hill Companies, Inc All rights reserved 525 Learning Outcomes (cont.) 52.13 Describe the procedure of performing spirometry 52.14 Describe the procedure for obtaining a performing peak expiratory flow rate 52.15 Describe the procedure for performing pulse oximetry testing © 2011 The McGraw-Hill Companies, Inc All rights reserved 526 Introduction • Patients often have cardiovascular or respiratory problems • Medical assistant – – Perform screening and/or diagnostic testing Understand the anatomy and physiology of the heart and respiratory system © 2011 The McGraw-Hill Companies, Inc All rights reserved 527 The Medical Assistant’s Role • Electrocardiography – Graphic recording of the electrical impulses of the heart – Uses • Evaluate symptoms of heart disease • Check effectiveness or side effects of medications General examination â 2011 The McGraw-Hill Companies, Inc All rights reserved 528 The Medical Assistant’s Role (cont.) • Pulmonary function tests – Measure and evaluate a patient’s lung capacity and volume – Uses • Help detect and diagnose pulmonary problems • Monitor respiratory disorders • Evaluate effectiveness of treatments © 2011 The McGraw-Hill Companies, Inc All rights reserved 529 Anatomy of the Heart • Muscular double pump – Right – receives blood from the body, sends it to the lungs – Left – receives blood from the lungs, sends it out to all parts of the body • Four chambers – Two atria Two ventricles Valves Septum â 2011 The McGraw-Hill Companies, Inc All rights reserved 5210 Physiology of the Heart • Systole – contraction phase • Diastole – relaxation phase • Cardiac cycle – sequence of contraction and relaxation • Cardiac muscle fibers are interconnected so when one is stimulated to contract, all fibers in the group contract © 2011 The McGraw-Hill Companies, Inc All rights reserved 5250 Performing Spirometry (cont.) • Performing the maneuver – Urge patient to blow hard and to continue blowing – Provide feedback on performance – Obtain three acceptable maneuvers – Observe the patient’s symptoms – Notify physician immediately if symptoms occur © 2011 The McGraw-Hill Companies, Inc All rights reserved 5251 Performing Spirometry (cont.) • Determining effectiveness of medications – Perform test before patient takes medication for day – Repeat after patient takes the medication • Special considerations – Uncooperative patients – Patients who not understand – Patients who cannot follow directions – Patients who cannot perform the procedure © 2011 The McGraw-Hill Companies, Inc All rights reserved 5252 Performing Spirometry (cont.) • Calibration – Daily – keep logbook – Calibration syringe – standardized measuring instrument – Detect leaks – check time/volume graph • Results • Infection control – Clean equipment after each patient – Discard disposable supplies appropriately – Wash hands before and after each use – Evaluate ventilatory function – Screening for pulmonary disorders – Severity of problems – Response to therapy or medication © 2011 The McGraw-Hill Companies, Inc All rights reserved 5253 Peak Expiratory Flow Rate • Determines amount of air that can be quickly forced from the lungs • Peak flow meter • Reveals narrowing of airways before an asthma attack • Peak flow zones – Different for each patient – Green zone – good control of asthma – Yellow zone – large airways are beginning to narrow – Red zone – medical emergency © 2011 The McGraw-Hill Companies, Inc All rights reserved 5254 Pulse Oximetry • Non-invasive measurement of the oxygen saturation in arterial blood – Hemoglobin absorbs infrared light – Measures amount of light absorbed – Hypoxemia – less than 95% • Uses – Pulmonary and cardiac conditions – Postoperatively – Sleep apnea © 2011 The McGraw-Hill Companies, Inc All rights reserved 5255 Apply Your Knowledge What is the purpose of PFTs? ANSWER: To evaluate lung volume and capacity What is FVC? ANSWER: It is forced vital capacity: the greatest volume of air that can be expelled with a rapid, forced expiration It is the measurement of the volume of air expelled and amount of time taken to expel it © 2011 The McGraw-Hill Companies, Inc All rights reserved 5256 YIPPEE! for Apply Your Knowledge Joey Jackson called to ask about taking his asthma medicine He said he has been using his peak flow meter and the readings have been in his yellow zone What you tell him? ANSWER: This means that his large airways are beginning to narrow and that he should take his medication as prescribed Joey decided to come to the office and you check his oxygen saturation with the pulse oximeter The reading was 93% What does this mean and what should you do? ANSWER: Joey is hypoxemic You need to notify the physician and document findings © 2011 The McGraw-Hill Companies, Inc All rights reserved 5257 In Summary 52.1 The heart is a muscular pump that circulates blood throughout the body There are two upper chambers (atria) and two lower chambers (ventricles) Contraction of the atria followed by contraction of the ventricles moves the blood 52.2 The conduction system of the heart is responsible for the electrical pathway that occurs during a heartbeat The pathway begins with the SA node and travels through the AV node – bundle of HIS – right and left bundle branches and ends with the Purkinje fibers © 2011 The McGraw-Hill Companies, Inc All rights reserved 5258 In Summary (cont.) 52.3 The electrical impulses are represented in wave forms or deflections Each deflection is labeled by letters PQRSTU and represents a part of the pattern 52.4 The electrocardiograph consists of the following components: electrodes, which detect and conduct electrical impulses to the electrocardiograph; amplifier, which increases the signal, making the heartbeat visible; stylus, which records the movement on the ECG paper; leads, combinations of electrodes, each providing different views of the electrical activity of the heart; and ECG paper, special heat-sensitive paper used for recording the ECG tracing © 2011 The McGraw-Hill Companies, Inc All rights reserved 5259 In Summary (cont.) 52.5 The limb leads are placed on the fleshy part of the upper arms and lower legs The precordial leads are placed across and down the left side of the chest in the 4th and 5th intercostal space All leads must be placed in a standard and concise manner 52.6 The steps in obtaining an accurate ECG include: identifying the patient; properly placing the limb and chest electrodes; attaching the lead wires; entering the patient data into the ECG machine; running the tracing; checking the tracing for artifacts; disconnecting the patient from the lead wires and removing electrodes; and assisting the patient as required © 2011 The McGraw-Hill Companies, Inc All rights reserved 5260 In Summary (cont.) 52.7 Artifacts that can occur during ECG testing include: AC interference – Caused by small amounts of electricity given off by other pieces of equipment in the room and picked up by the ECG machine This can be corrected by turning off or unplugging other appliances in the room Flat line – Caused by a loose or disconnected wire, or two wires that are switched This can be corrected by checking and correcting lead placement Somatic interference – Caused by patient muscle movement This can be corrected by reminding the patient to remain still, keeping the patient warm, and placing the limb electrodes closer to the trunk of the body Wandering baseline – Caused by somatic interference, mechanical problems, or improper electrode application This can be corrected by reminding the patient to remain still, removing any oil or lotion from the patient’s skin before applying the electrodes, reapplying the electrodes, or uncrossing any crossed electrodes © 2011 The McGraw-Hill Companies, Inc All rights reserved 5261 In Summary (cont.) 52.8 The ECG is interpreted by assessing the heart rhythm, heart rate, the length and position of intervals and segments and any wave changes that occur 52.9 A medical assistant should recognize abnormal heart rhythms such as premature ventricular contractions, ventricular fibrillation, and atrial fibrillation 52.10 Exercise electrocardiography is referred to as stress testing This measures the efficiency of the heart during constant or increasing workload © 2011 The McGraw-Hill Companies, Inc All rights reserved 5262 In Summary (cont.) 52.11 A Holter monitor is used to measure the heart’s activity over a 24-hour period and when the patient has intermittent chest pain or discomfort and a normal ECG and stress test 52.12 Forced vital capacity is the measurement of the greatest volume of air expelled when a patient performs a rapid, forced expiration The lung’s ability to function is measured by the volume of air expelled and the time taken to perform maneuver 52.13 Accurate spirometry testing requires proper patient positioning, coaching the patient during the procedure, obtaining three acceptable maneuvers, and recording the results in the patient’s chart © 2011 The McGraw-Hill Companies, Inc All rights reserved 5263 In Summary (cont.) 52.14 A peak expiratory flow rate is obtained by having the patient sit or stand using good posture, take in as deep a breath as possible, and blow out through the peak flow meter as fast and as hard as possible three times The highest reading of the three is the peak flow rate and should be recorded in the patient’s chart 52.15 Pulse oximetry testing is performed by applying the pulse oximeter to the patient’s finger or toe, attaching the sensor cable to the oximeter, turning the oximeter on, setting the alarm limits for high and low oxygen saturations, and reading the patient’s oxygen saturation levels The oxygen saturation levels should be recorded in the patient’s chart © 2011 The McGraw-Hill Companies, Inc All rights reserved 5264 End of Chapter 52 As the arteries grow hard, the heart grows soft ~ H. L. Mencken © 2011 The McGraw-Hill Companies, Inc All rights reserved ... reserved 52 21 The Electrocardiograph (cont.) • Controls – Standardization control – Speed selector – 25mm/sec standard – Sensitivity control – adjusts height of tracing – Centering control – adjusts... • Electrodes and electrolyte products – Electrolyte – enhances transmissions of electric current – Electrodes • Ten areas of the body – Right and left arms – Right and left legs – Six locations... reserved 52 6 Introduction • Patients often have cardiovascular or respiratory problems • Medical assistant – – Perform screening and/ or diagnostic testing Understand the anatomy and physiology