Prescribed: Amiodarone hydrochloride 5 mg/kg as IV push now.

Available: Amiodarone hydrochloride 150 mg/3 mL. Patient weight: 80 kg. How many mL will the nurse administer for the prescribed dose?

Choice C rationale

Asystole, or ventricular standstill, must be confirmed in at least two different leads to rule out fine ventricular fibrillation or technical errors like a loose lead. Treating "false" asystole can delay life-saving defibrillation if the patient is actually in a shockable rhythm. Assessment is the first step in the nursing process. Verifying the rhythm and checking the patient's pulse ensures that the clinical intervention matches the true physiological state of the patient.

Choice A rationale

Epinephrine is the primary medication used during the resuscitation of a patient in asystole according to ACLS guidelines. It works by causing peripheral vasoconstriction and increasing coronary perfusion pressure. However, the nurse should never administer medication based on a monitor rhythm alone without first assessing the patient and confirming the rhythm in multiple leads. Once confirmed and CPR is initiated, epinephrine 1 mg is given every 3 to 5 minutes during the arrest.

Choice B rationale

Intubation is an important part of advanced airway management during cardiac arrest to ensure adequate oxygenation and protection against aspiration. While it is a component of the ACLS algorithm, it is not the initial action. The nurse must first verify the rhythm and begin high-quality chest compressions. Airway management often occurs simultaneously with or after the initiation of CPR and the confirmation of the cardiac arrest rhythm to maximize perfusion.

Choice D rationale

Atropine was previously included in the asystole algorithm to treat potential vagal discharge, but it is no longer recommended by the American Heart Association for asystole or pulseless electrical activity. Current protocols focus on high-quality CPR and early epinephrine administration. Administering atropine would be an outdated practice and does not address the primary need for assessment and perfusion in a patient who has no detectable electrical activity or mechanical pulse.

Choice D rationale

To ensure the accuracy of the hemodynamic data from a radial arterial line, the nurse must reference and zero the system. Referencing involves positioning the transducer at the phlebostatic axis, which is the level of the atria at the fourth intercostal space, mid-axillary line. Zeroing the line negates the effects of atmospheric pressure on the monitoring system. This ensures that the pressure displayed on the monitor represents only the patient's internal physiological blood pressure, preventing false high or low readings.

Choice A rationale

Flushing the arterial line is done to maintain patency of the catheter and clear the tubing of blood after sampling. However, a continuous flush system usually handles this at a rate of 3 mL per hour. Manually flushing for 10 seconds is not a standard requirement prior to taking a reading and could potentially cause a fluid bolus or damage the artery if done with excessive force. It does not contribute to the calibration or accuracy of the electronic pressure transducer.

Choice B rationale

While positioning is important, the correct landmark for hemodynamic monitoring is the phlebostatic axis, not the sternal angle. The sternal angle, or Angle of Louis, is used as a landmark for identifying the second rib and auscultating heart sounds, but it does not correspond to the level of the heart's chambers for pressure monitoring. Using the incorrect reference point will lead to hydrostatic pressure errors, where every inch the transducer is below the heart adds approximately 2 mmHg to the reading.

Choice C rationale

The Allen test is a diagnostic physical exam used to assess the patency of the ulnar artery and the adequacy of collateral circulation to the hand. This must be performed before the arterial line is even inserted into the radial artery to ensure that the hand will remain perfused if the radial artery becomes occluded. Once the line is already in place, performing an Allen test is not a prerequisite for obtaining a routine pressure reading from the monitor.