A patient is in pulseless arrest and the EKG shows asystole. What is the drug used in ACLS for this rhythm?

Choice A rationale

Synchronized cardioversion requires the machine to sense the QRS complex specifically. If the discharge occurs during the P wave, it would not successfully terminate the tachyarrhythmia. The P wave represents atrial depolarization, but the goal is to safely reset the ventricular rhythm. Incorrectly timing the shock could lead to ineffective therapy or trigger more dangerous rhythms if the electrical discharge happens during the wrong phase of cardiac activity.

Choice B rationale

Defibrillation at 360 joules is an unsynchronized high energy shock used for pulseless rhythms like ventricular fibrillation or pulseless ventricular tachycardia. Using this for a patient with supraventricular tachycardia who still has a pulse and blood pressure, even if low, is inappropriate. An unsynchronized shock delivered during the vulnerable period of the T wave could actually induce ventricular fibrillation, worsening the patient's critical condition and leading to immediate cardiac arrest.

Choice C rationale

Defibrillation at 100 joules is also an unsynchronized delivery of electrical energy. While the energy level is lower than 360 joules, the lack of synchronization remains the primary safety concern. Patients in supraventricular tachycardia with signs of hemodynamic instability, such as a blood pressure of 80/40 and chest pain, require synchronized cardioversion to avoid the R on T phenomenon. Unsynchronized shocks are strictly reserved for patients who lack a discernible pulse or rhythm.

Choice D rationale

Selecting sync ensures the defibrillator delivers the electrical shock exactly on the R wave, which is the peak of ventricular depolarization. This timing avoids the vulnerable repolarization period of the T wave. For a patient with supraventricular tachycardia and hypotension, synchronization is vital to prevent inducing ventricular fibrillation. This precise timing allows the heart to depolarize simultaneously and provides the opportunity for the sinoatrial node to resume its role as the primary pacemaker.

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.