Nursing Science Oxygenation Answer Key

Chapter 41: Oxygenation MULTIPLE CHOICE 1. A nurse is teaching staff about the conduction of the heart. In which order will the nurse present the conduction cycle, starting with the first structure? 1. Bundle of His 2. Purkinje network 3. Intraatrial pathways 4. Sinoatrial (SA) node 5. Atrioventricular (AV) node a. 5, 4, 3, 2, 1 b. 4, 3, 5, 1, 2 c. 4, 5, 3, 1, 2 d. 5, 3, 4, 2, 1 ANS: B The conduction system originates with the SA node, the “pacemaker” of the heart. The electrical impulses are transmitted through the atria along intraatrial pathways to the AV node. It assists atrial emptying by delaying the impulse before transmitting it through the Bundle of His and the ventricular Purkinje network. DIF:Understand (comprehension)REF:875 OBJ: Describe the structure and function of the cardiopulmonary system. TOP: Teaching/Learning MSC: Physiological Adaptation 2. A nurse is teaching the patient with mitral valve problems about the valves in the heart. Starting on the right side of the heart, describe the sequence of the blood flow through these valves. 1. Mitral 2. Aortic 3. Tricuspid 4. Pulmonic a. 1, 3, 2, 4 b. 4, 3, 2, 1 c. 3, 4, 1, 2 d. 2, 4, 1, 3 ANS: C The blood flows through the valves in the following direction: tricuspid, pulmonic, mitral, and aortic. DIF:Understand (comprehension)REF:874 OBJ: Describe the structure and function of the cardiopulmonary system. TOP: Teaching/Learning MSC: Physiological Adaptation 3. A nurse explains the function of the alveoli to a patient with respiratory problems. Which information about the alveoli’s function will the nurse share with the patient? a. Carries out gas exchange b. Regulates tidal volume c. Produces hemoglobin d. Stores oxygen ANS: A The alveolus is a capillary membrane that allows gas exchange of oxygen and carbon dioxide during respiration. The alveoli do not store oxygen, regulate tidal volume, or produce hemoglobin. DIF:Understand (comprehension)REF:872-873 OBJ: Describe the physiological processes of ventilation, perfusion, and exchange of respiratory gases. TOP: Teaching/Learning MSC: Physiological Adaptation 4. A nurse auscultates heart sounds. When the nurse hears S2, which valves is the nurse hearing close? a. Aortic and mitral b. Mitral and tricuspid c. Aortic and pulmonic d. Mitral and pulmonic ANS: C As the ventricles empty, the ventricular pressures decrease, allowing closure of the aortic and pulmonic valves, producing the second heart sound, S2. The mitral and tricuspid produce the first heart sound, S1. The aortic and mitral do not close at the same time. The mitral and pulmonic do not close at the same time. DIF:Apply (application)REF:874 OBJ: Describe the structure and function of the cardiopulmonary system. TOP:AssessmentMSC:Health Promotion and Maintenance 5. The nurse is teaching about the process of exchanging gases through the alveolar capillary membrane. Which term will the nurse use to describe this process? a. Ventilation b. Surfactant c. Perfusion d. Diffusion ANS: D Diffusion is the process of gases exchanging across the alveoli and capillaries of body tissues. Ventilation is the process of moving gases into and out of the lungs. Surfactant is a chemical produced in the lungs to maintain the surface tension of the alveoli and keep them from collapsing. Perfusion is the ability of the cardiovascular system to carry oxygenated blood to tissues and return deoxygenated blood to the heart. DIF:Understand (comprehension)REF:873 OBJ: Describe the physiological processes of ventilation, perfusion, and exchange of respiratory gases. TOP: Teaching/Learning MSC: Physiological Adaptation 6. A nurse is caring for a patient who was in a motor vehicle accident that resulted in cervical trauma to C4. Which assessment is the priority? a. Pulse b. Respirations c. Temperature d. Blood pressure ANS: B Respirations and oxygen saturation are the priorities. Cervical trauma at C3 to C5 usually results in paralysis of the phrenic nerve. When the phrenic nerve is damaged, the diaphragm does not descend properly, thus reducing inspiratory lung volumes and causing hypoxemia. While pulse and blood pressure are important, respirations are the priority. Temperature is not a high priority in this situation. DIF:Analyze (analysis)REF:877 OBJ:Assess for the risk factors affecting a patient’s oxygenation. TOP:AssessmentMSC:Management of Care 7. The patient is breathing normally. Which process does the nurse consider is working properly when the patient inspires? a. Stimulation of chemical receptors in the aorta b. Reduction of arterial oxygen saturation levels c. Requirement of elastic recoil lung properties d. Enhancement of accessory muscle usage ANS: A Inspiration is an active process, stimulated by chemical receptors in the aorta. Reduced arterial oxygen saturation levels indicate hypoxemia, an abnormal finding. Expiration is a passive process that depends on the elastic recoil properties of the lungs, requiring little or no muscle work. Prolonged use of the accessory muscles does not promote effective ventilation and causes fatigue. DIF:Understand (comprehension)REF:872 OBJ: State the process of the neural and chemical regulation of respiration. TOP: Assessment MSC: Physiological Adaptation 8. The home health nurse recommends that a patient with respiratory problems install a carbon monoxide detector in the home. What is the rationale for the nurse’s action? a. Carbon monoxide detectors are required by law in the home. b. Carbon monoxide tightly binds to hemoglobin, causing hypoxia. c. Carbon monoxide signals the cerebral cortex to cease ventilations. d. Carbon monoxide combines with oxygen in the body and produces a deadly toxin. ANS: B Carbon monoxide binds tightly to hemoglobin; therefore, oxygen is not able to bind to hemoglobin and be transported to tissues, causing hypoxia. A carbon monoxide detector is not required by law, does not signal the cerebral cortex to cease ventilations, and does not combine with oxygen but with hemoglobin to produce a toxin. DIF:Apply (application)REF:876 OBJ: Describe nursing care interventions used to promote oxygenation in the primary care, acute care, and restorative and continuing care settings. TOP: Planning MSC:Health Promotion and Maintenance 9. While performing an assessment, the nurse hears crackles in the patient’s lung fields. The nurse also learns that the patient is sleeping on three pillows to help with the difficulty breathing during the night. Which condition will the nurse most likely observe written in the patient’s medical record? a. Atrial fibrillation b. Myocardial ischemia c. Left-sided heart failure d. Right-sided heart failure ANS: C Left-sided heart failure results in pulmonary congestion, the signs and symptoms of which include shortness of breath, cough, crackles, and paroxysmal nocturnal dyspnea (difficulty breathing when lying flat). Right-sided heart failure is systemic and results in peripheral edema, weight gain, and distended neck veins. Atrial fibrillation is often described as an irregularly irregular rhythm; rhythm is irregular because of the multiple pacemaker sites. Myocardial ischemia results when the supply of blood to the myocardium from the coronary arteries is insufficient to meet myocardial oxygen demands, producing angina or myocardial infarction. DIF:Apply (application)REF:878 OBJ: Assess for the physical manifestations that occur with alterations in oxygenation. TOP: Assessment MSC: Physiological Adaptation 10. A patient has a myocardial infarction. On which primary blood vessel will the nurse focus care to reduce ischemia? a. Superior vena cava b. Pulmonary artery c. Coronary artery d. Carotid artery ANS: C A myocardial infarction is the lack of blood flow due to obstruction to the coronary artery, which supplies the heart with blood. The superior vena cava returns blood back to the heart. The pulmonary artery supplies deoxygenated blood to the lungs. The carotid artery supplies blood to the brain. DIF:Understand (comprehension)REF:878 OBJ: Differentiate among the physiological processes of cardiac output, myocardial blood flow, and coronary artery circulation. TOP: Planning MSC: Physiological Adaptation 11. A nurse is teaching a health class about the heart. Which information from the class members indicates teaching by the nurse is successful for the flow of blood through the heart, starting in the right atrium? a. Right ventricle, left ventricle, left atrium b. Left atrium, right ventricle, left ventricle c. Right ventricle, left atrium, left ventricle d. Left atrium, left ventricle, right ventricle ANS: C Unoxygenated blood flows through the venae cavae into the right atrium, where it is pumped down to the right ventricle; the blood is then pumped out the pulmonary artery and is returned oxygenated via the pulmonary vein to the left atrium, where it flows to the left ventricle and is pumped out to the rest of the body via the aorta. DIF:Understand (comprehension)REF:874 OBJ: Describe the structure and function of the cardiopulmonary system. TOP: Teaching/Learning MSC: Health Promotion and Maintenance 12. The nurse suspects the patient has increased afterload. Which piece of equipment should the nurse obtain to determine the presence of this condition? a. Pulse oximeter b. Oxygen cannula c. Blood pressure cuff d. Yankauer suction tip catheter ANS: C A blood pressure cuff is needed. The diastolic aortic pressure is a good clinical measure of afterload. Afterload is the resistance to left ventricular ejection. In hypertension the afterload increases, making cardiac workload also increase. A pulse oximeter is used to monitor the level of arterial oxygen saturation; it will not help determine increased afterload. While an oxygen cannula may be needed to help decrease the effects of increased afterload, it will not help determine the presence of afterload. A Yankauer suction tip catheter is used to suction the oral cavity. DIF:Analyze (analysis)REF:875 OBJ: Describe the relationship of cardiac output, preload, afterload, contractility, and heart rate to the process of oxygenation. TOP: Planning MSC: Physiological Adaptation 13. A patient has heart failure and cardiac output is decreased. Which formula can the nurse use to calculate cardiac output? a. b. c. d. Myocardial contractility × Myocardial blood flow Ventricular filling time/Diastolic filling time Stroke volume × Heart rate Preload/Afterload ANS: C Cardiac output can be calculated by multiplying the stroke volume and the heart rate. The other options are not measures of cardiac output. DIF:Understand (comprehension)REF:875 OBJ: Differentiate among the physiological processes of cardiac output, myocardial blood flow, and coronary artery circulation. TOP: Assessment MSC: Physiological Adaptation 14. A patient’s heart rate increased from 94 to 164 beats/min. What will the nurse expect? a. Increase in diastolic filling time b. Decrease in hemoglobin level c. Decrease in cardiac output d. Increase in stroke volume ANS: C With a sustained heart rate greater than 160 beats/min, diastolic filling time decreases, decreasing stroke volume and cardiac output. The hemoglobin level would not be affected. DIF:Understand (comprehension)REF:875 OBJ: Describe the relationship of cardiac output, preload, afterload, contractility, and heart rate to the process of oxygenation. TOP: Planning MSC: Physiological Adaptation 15. The nurse is careful to monitor a patient’s cardiac output. Which goal is the nurse trying to achieve? a. To determine peripheral extremity circulation b. To determine oxygenation requirements c. To determine cardiac dysrhythmias d. To determine ventilation status ANS: A Cardiac output indicates how much blood is being circulated systemically throughout the body to the periphery. The amount of blood ejected from the left ventricle each minute is the cardiac output. Oxygen status would be determined by pulse oximetry and the presence of cyanosis. Cardiac dysrhythmias are an electrical impulse monitored through ECG results. Ventilation status is measured by respiratory rate, pulse oximetry, and capnography.