The nurse notes increasing systemic vascular resistance readings on a patient in the intensive care unit. The nurse understands the effects of this change to include which of the following?

Choice A rationale

Administering sedative or paralytic agents is typically performed prior to or during the actual intubation process to facilitate tube passage and prevent airway trauma. Once the tube is inserted and the cuff is inflated, the priority shifts to verification of placement rather than further sedation. Giving these drugs after insertion does not provide any diagnostic data regarding whether the tube is in the trachea or the esophagus.

Choice B rationale

A chest x-ray is the definitive gold standard for confirming the depth of endotracheal tube placement. It ensures the distal tip of the tube is positioned approximately 2 to 5 cm above the carina. While other methods confirm the tube is in the trachea, the x-ray is essential to ensure it has not migrated into the right mainstem bronchus, which would cause unilateral lung expansion and potential collapse.

Choice C rationale

End-tidal carbon dioxide detection provides immediate physiological feedback that the tube is located within the respiratory tract. Since CO2 is a byproduct of alveolar gas exchange, its presence in exhaled air indicates the tube is in the trachea rather than the esophagus. A colorimetric changer or capnography waveform is a primary tool used immediately after intubation to rule out esophageal placement before further interventions are performed.

Choice D rationale

Auscultation is a critical immediate step to verify bilateral lung expansion and rule out unintentional esophageal or endobronchial intubation. The nurse should listen for equal breath sounds over the midaxillary lines and ensure there are no gurgling sounds over the epigastrium. Epigastric sounds suggest the tube is in the stomach. Breath sounds must be assessed early to ensure both lungs are being ventilated prior to securing the device.

Choice E rationale

Arterial blood gases are useful for evaluating the long-term effectiveness of ventilation and oxygenation after the patient is stabilized on a ventilator. However, they are not used for the initial confirmation of tube placement because the results take too long to obtain. Verification must be instantaneous using physical assessment and CO2 detection to prevent hypoxia. Normal pH is 7.35 to 7.45, and normal PaO2 is 80 to 100 mmHg.

Choice B rationale

Third-degree or complete heart block occurs when there is a total dissociation between the atria and the ventricles. No atrial impulses reach the ventricles, resulting in independent pacing of both chambers. Because the ventricular escape rhythm is typically slow (20 to 40 beats per minute) and unreliable, it cannot maintain adequate cardiac output. A permanent pacemaker is the definitive treatment to provide a reliable heart rate and restore synchronized electrical activity, preventing syncope or cardiac arrest.

Choice A rationale

This medication is a calcium channel blocker used primarily to slow the ventricular rate in rhythms like atrial fibrillation or supraventricular tachycardia by delaying conduction through the AV node. In third-degree heart block, the AV node is already non-functional or completely blocked. Administering a drug that further slows AV conduction or suppresses escape rhythms would be dangerous and could lead to ventricular asystole. It is contraindicated in this setting where the heart rate is already critically low.

Choice C rationale

Third-degree heart block is the highest degree of block and represents a medical emergency due to the risk of profound bradycardia and low cardiac output. Monitoring or observation is inappropriate because the patient is at high risk for sudden cardiac death. Immediate intervention with transcutaneous pacing is required as a bridge until a permanent pacemaker can be placed. Waiting for further progression is not a clinical option as there is no higher degree of block to observe.

Choice D rationale

This is a Class 1A antiarrhythmic used to treat ventricular arrhythmias and certain supraventricular tachycardias by slowing conduction velocity. Like other antiarrhythmics, it can further suppress the heart's natural escape rhythms. In the presence of a complete heart block, where the patient relies on a slow ventricular escape rhythm to survive, this medication could eliminate that remaining heartbeat entirely. It is not indicated for the treatment of bradycardias or AV blocks and would be harmful.