Missed questions on CCRN practice exams(* before = not missed, but needs review.)

Ashman phenomenon is a predisposition for aberrancy when which of the following occurs? A. A long P-P interval is followed by a short P-P interval. B. A short P-P interval is followed by a long P-P interval. C. A short R-R interval is followed by a long R-R interval. D. A long R-R interval is followed by a short R-R interval. D Ashman phenomenon occurs when a short cycle follows a long cycle. Refractory periods are related to cycle length. When a short cycle follows a long cycle, the QRS complex that ends the short cycle interrupts the long refractory period of the long cycle. That beat is likely to be conducted aberrantly. * Which is a normal oxygen consumption index (VO2I)? A. Approximately 50 ml/min/m2 B. Approximately 100 ml/min/m2 C. Approximately 150 ml/min/m2 D. Approximately 200 ml/min/m2 C Normal arterial oxygen saturation is 100%, and normal venous oxygen saturation is 75%. The tissues used 25%. The normal arterial oxygen content is 20 ml/dl, and normal venous oxygen content is 15 ml/dl. The tissues used 25%. The normal oxygen delivery (DO2) is 1000 ml/min, and normal VO2 is 250 ml/min. The tissues used 25%. The normal DO2I is 600 ml/min/m2, so consider what is 25% of 600 ml/min/m2? The normal VO2I is 150 ml/min/m2. 00:05 01:14 * Increasing the driving pressure of oxygen increases blood oxygenation. Driving pressure of oxygen is affected by which two factors? A. Compliance and resistance B. Oxygen concentration and barometric pressure C. Hemoglobin and arterial oxygen saturation (SaO2) D. Cardiac output and systemic vascular resistance B The driving pressure of oxygen across the alveolar-capillary membrane is affected by the concentration of the gas (FiO2) and the barometric pressure (760 mm Hg at sea level). Therefore blood oxygenation is increased by increasing the FiO2 or by increasing the pressure, such as with a hyperbaric chamber or the addition of continuous positive airway pressure or positive end-expiratory pressure.Compliance and resistance affect the work of breathing. Hemoglobin and SaO2 affect the CaO2 (content of oxygen in the arterial blood). Cardiac output and systemic vascular resistance affect blood pressure. Emergency decompression of a tension pneumothorax includes needle puncture at which of the following locations? A. Fifth intercostal space at the midclavicular line on the affected side B. Second intercostal space at the midclavicular line on the affected side C. Second intercostal space at the midaxillary line on the affected side D. Fifth intercostal space at the midaxillary line on the affected side B Emergency decompression of a tension pneumothorax is performed by insertion of a large-bore needle into the thorax at the second intercostal space at the midclavicular line. * Which of the following statements about colloids is correct? A. They are classified as hypotonic, hypertonic, and isotonic. B. They increase interstitial and intracellular volume. C. They increase intravascular colloidal oncotic pressure. D. They are the first-line treatment in fluid resuscitation. C Colloids increase intravascular colloidal oncotic pressure and pull fluid from the interstitial space into the intravascular space. Current research has not found a benefit of colloids over crystalloids in fluid resuscitation, and colloids are much more expensive. A 52-year-old patient with a history of alcoholism is admitted with massive esophageal bleeding. The patient has had several blood transfusions. The toxic effects of citrate in stored blood are caused by a fall in which electrolyte? A. Calcium B. Sodium C. Potassium D. Phosphorus A Calcium binds with the citrate that reduces the ionized calcium level and causes tetany. Possible interventions for the most clinically significant intracranial pressure (ICP) waves include any of the following except: A. administration of mannitol. B. repositioning of the patient. C. initiation of hyperventilation therapy. D. drainage of cerebrospinal fluid (CSF) via an intraventricular catheter. B When patients have elevation in ICP, it is important not to do anything that might increase the ICP further. Mannitol administration and CSF drainage are methods that are often used to reduce acute increases in ICP. Hyperventilation therapy might be used to cause cerebral vasoconstriction in a time of crisis but should not be used routinely. Repositioning the patient may increase the ICP. Avoid anything that may increase ICP, especially in times of crisis. "Administration of mannitol," "initiation of hyperventilation therapy," and "drainage of cerebrospinal fluid (CSF) via an intraventricular catheter" all cause the loss of volume from the head. Mannitol decreases cerebral edema, hyperventilation causes cerebral vessel constriction and decrease in blood volume in the head, and CSF drainage reduces the volume of CSF in the head. Repositioning the patient may increase ICP. Also note that repositioning the patient is a general statement versus the other more specific options. Choose "repositioning of the patient" as an intervention that should not be initiated. A 72-year-old man arrived in the emergency department after 4 hours of substernal pain radiating to the left arm. He has a 100 pack-year history of cigarette smoking, chronic obstructive pulmonary disease, and intermittent claudication. His electrocardiogram on admission shows sinus tachycardia with a rate of 120 beats/min and ST segment elevation in leads I, AVL, and V3 to V6. Vital signs include blood pressure, 150/84 mm Hg; respiratory rate, 15 breaths/min; functional oxygen saturation (SpO2), 95%; and temperature, 38.3° C (100.9° F). An S4 is noted during cardiac auscultation. This sound indicates: A. atrial contraction and propulsion of blood into a noncompliant ventricle. B. inflammation of the pericardium. C. opening of a defective semilunar valve. D. rapid ventricular filling into an already distended ventricle. A An S4 occurs during the end of diastole when the atria contract but the ventricle is noncompliant. An S4 occurs in myocardial ischemia, infarction, and hypertrophy. Most patients with an acute myocardial infarction have an S4 for the first 48 hours. * Which of the following are the two clinical hallmarks of acute respiratory distress syndrome? A. Increased lung compliance and pulmonary edema B. Increased functional residual capacity and decreased compliance C. Refractory hypoxemia and decreased lung compliance D. Refractory hypoxemia and increased functional residual capacity C Intra-alveolar fluid and damage to type II pneumocytes result in a decrease in the amount and effectiveness of surfactant. This causes alveolar collapse (decreased functional residual capacity), pulmonary edema, decrease in lung compliance, and massive intrapulmonary shunt. Intrapulmonary shunt causes severe hypoxemia that is refractory to oxygen therapy. An aortic tear commonly is associated with which of the following? A. Acceleration-deceleration injury B. Barotrauma C. Penetrating injury of the chest wall D. Blunt force injury to the chest wall A Acceleration-deceleration injury may cause a shearing tear of the aorta. This usually occurs with a high-speed motor vehicle collision when the vehicle, the body, and then the heart make a sudden stop. A 57-year-old man with an acute anterior myocardial infarction has the following vital signs and hemodynamic parameters: Blood pressure102/60 mm Hg Heart rate116 beats/min Respiratory rate24 breaths/min Right atrial pressure8 mm Hg Pulmonary artery occlusive pressure22 mm Hg Cardiac index1.6 L/min/m2 Systemic vascular resistance index3300 dynes/sec/cm-5 He has crackles at his lung bases and an S3 at his apex. He is pain free at this time but continues to be dyspneic. He is having premature ventricular contractions and short runs of ventricular tachycardia. Which of the following did not occur by sympathetic nervous system (SNS) innervation in an attempt to compensate for the decreased cardiac output and index? A. Increased heart rate B. Increased afterload C. Increased contractility D. Increased ectopy C α receptors of the SNS cause vasoconstriction and shift blood from nonessential (skin, bowel, kidney) to essential (heart and brain) organs. β1 receptors increase heart rate (positive chronotropic effect), increase contractility (positive inotropic effect), and increase conductivity (positive dromotropic effect). The dromotropic effect increases the propensity for ventricular ectopy. β2 receptors cause bronchodilation and vasodilation. In this case, the increase in heart rate and ectopy potential is caused by stimulation of the β1 receptors. The increase in afterload is caused by stimulation of the α receptors. Contractility would have been increased by β1 stimulation, but the patient's myocardium is unable to respond, and contractility remains decreased. Which of the following is a clinical indication of diastolic dysfunction? A. S3 B. S4 C. Murmur D. Midsystolic click B S4 is an indication of diastolic dysfunction, which is caused by ventricular noncompliance. S3 is an indication of systolic dysfunction. A murmur is associated with intracardiac turbulence such as a septal defect or valve problem. A midsystolic click is associated with mitral valve prola