Important AACN CCRN-Adult Exam Questions

Answer: B

Explanation:

Subcutaneous emphysema (SE) is a condition where gas or air accumulates in the subcutaneous tissue layer of the skin, causing swelling and a crackling sensation when touched. SE can occur after esophagectomy, a surgical procedure to remove part or all of the esophagus, due to air leakage from the anastomosis site or the lung. SE can also be a sign of a more serious complication, such as anastomotic leakage, mediastinitis, or tracheal injury12. Therefore, the nurse should expect an order for a CT scan, which is a diagnostic imaging test that can detect the source and extent of the air leakage and any associated complications. A CT scan can also guide the appropriate management of SE, which may include conservative measures, such as increasing the suction of the chest tube, or more invasive interventions, such as surgical repair or drainage123. Chest tube insertion, IV antibiotics, and gastric decompression are not likely to be ordered for SE after esophagectomy, as they do not address the underlying cause of the air leakage or the potential complications. Chest tube insertion may be indicated for pneumothorax, but not for SE alone. IV antibiotics may be indicated for infection, but not for SE alone. Gastric decompression may be indicated for gastric distension, but not for SE alone.

Answer: C

Explanation:

A patient with COPD may have a chronically elevated PaCO2 and rely on hypoxia as the main stimulus for breathing. If the patient receives too much oxygen, this may reduce the hypoxic drive and cause respiratory depression, leading to lethargy and hypercapnia. O2 toxicity, absorption atelectasis, and decreased end-tidal CO2 are unlikely to occur with 4 L/min of O2 via nasal cannula in a short period of time.

Reference Guide for CCRN (Adult), page 14.

Oxygen Saturation Target of 88-92% in COPD: Evidence-based Medicine?

Answer: D

Explanation:

A high mixed venous O2 saturation (SO2) indicates that the tissue cells are not extracting enough oxygen from the blood, which can be due to impaired cellular metabolism or increased oxygen delivery. In septic shock, there is often a mismatch between oxygen delivery and consumption, resulting in a high SO2 despite tissue hypoxia. Therefore, SO2 alone is not a reliable indicator of tissue perfusion in septic shock.

Mixed venous oxygen saturation (SvO2) monitoring * LITFL * CCC

SvO2 to monitor resuscitation of septic patients: let's just understand the basic physiology | Critical Care | Full Text

Reference Guide for CCRN (Adult), page 14.

Answer: D

Explanation:

Hypotension, or low blood pressure, is a late finding in hypovolemic shock, which means that it occurs when the condition has progressed to a severe stage. Hypotension indicates that the body's compensatory mechanisms, such as vasoconstriction, tachycardia, and increased cardiac output, have failed to maintain adequate perfusion and oxygen delivery to the vital organs. Hypotension is a sign of impending circulatory collapse and organ failure, and requires immediate intervention to restore blood volume and blood pressure. Hypotension is usually defined as a systolic blood pressure below 90 mmHg or a mean arterial pressure below 65 mmHg1.

Hypovolemic Shock: Causes, Symptoms and Treatment - Cleveland Clinic: This article states that ''As you keep losing blood or fluids, your systolic (top or first number) blood pressure comes down.'' and ''Your blood pressure drops very low and your heart rate and breathing get faster.''

Answer: A

Explanation:

In a patient with head trauma, the primary pathophysiology underlying acute respiratory failure often involves hypercapnia due to decreased minute ventilation. Head trauma can impair the central nervous system's ability to regulate breathing, leading to inadequate ventilation and a build-up of carbon dioxide (CO2) in the blood. Other factors like shifting of the oxyhemoglobin dissociation curve, increased intrapulmonary shunt, and dehydration due to diabetes insipidus may be present but are not the primary causes. Reference: CCRN Exam Handbook, AACN, page 25, section on Respiratory.