CPCT/A NHA Certified Patient Care Technician/Assistant - Set 5 - Part 3

Correct Answer: CPR, epinephrine, treat reversible causes

PEA and asystole are both non-shockable rhythms. CPR is started immediately, epinephrine is given every three to five minutes, and the team identifies and treats reversible causes, the Hs and Ts, throughout the resuscitation effort. Defibrillation is reserved for V-fib and pulseless V-tach, not for PEA or asystole. Antiarrhythmic drugs follow shocks for shockable rhythms, while non-shockable rhythms rely on CPR, epinephrine, and reversible-cause treatment. Cardioversion is for unstable tachyarrhythmias with a pulse and is inappropriate for arrest situations. Antiplatelet therapy is part of ACS management rather than cardiac arrest, so neither fits the PEA or asystole pathway. Vagal maneuvers and adenosine are stable supraventricular tachycardia treatments, not arrest pathway interventions. PEA and asystole do not have a pulse, so these interventions have no role in their management during resuscitation.

Correct Answer: PR prolongs, QRS widens, P waves vanish

As hyperkalemia worsens, peaked T waves are followed by PR prolongation, then QRS widening, then loss of P waves, then a sine-wave pattern, and finally asystole. Each step indicates increasing severity and the need for urgent treatment. Shortening of PR and narrowing of QRS are not features of progressive hyperkalemia. The actual progression involves prolongation of the PR interval and widening of the QRS as conduction slows under high potassium conditions. Symmetric T-wave inversion is more typical of ischemia or NSTEMI patterns. Hyperkalemia produces peaked T waves followed by PR prolongation and QRS widening, not the symmetric inversion described in this distractor. Hyperkalemia does not typically produce isolated sinus bradycardia with otherwise normal intervals. The progression involves PR prolongation, QRS widening, and loss of P waves rather than a simple bradycardia pattern alone.

Correct Answer: Mark is ten millimeters tall

At standard sensitivity of ten millimeters per millivolt, the calibration mark is ten millimeters tall, equal to two large boxes. Verifying this height before interpretation confirms the recording uses the standard amplitude reference for all leads. Five millimeters tall is the half-sensitivity mark, where amplitudes must be doubled during interpretation. It is used for very tall complexes that overflow the paper, and it is not the standard sensitivity setting. Twenty millimeters tall is the calibration mark at double sensitivity, where amplitudes must be halved during interpretation. It is not the standard mark, which is ten millimeters tall on a properly set device. Exactly one millimeter tall is far below any standard calibration height. The standard, half, and double sensitivities give heights of ten, five, and twenty millimeters respectively, none of which is one millimeter for the calibration mark.

Correct Answer: Lower high-frequency filter, warm patient

For tremor patients, lowering the high-frequency filter reduces tremor artifact, while warming the patient and using padded electrodes can stabilize the recording. Recording during stillness, when possible, also helps capture a usable diagnostic tracing. Applying less electrode gel worsens skin-electrode contact and increases impedance. The artifact is from movement, not contact, so reducing gel makes the recording quality worse without addressing the tremor source at all. Increasing paper speed does not eliminate tremor and may make it harder to interpret. The cause is patient movement, and adjusting the filter and supportive measures address the artifact better than speed alone. Skipping the EKG denies the team diagnostic information for time-sensitive evaluation. Recording with adjustments and documentation is the standard approach when tremor or other involuntary movement complicates the recording.

Correct Answer: Twenty-five millimeters per second

The standard paper speed is twenty-five millimeters per second for routine 12-lead EKG. At this speed, one small box equals zero point zero four seconds, and one large box equals zero point twenty seconds horizontally. Ten millimeters per second is too slow for routine recording and would compress waveforms beyond useful interpretation. The standard speed is twenty-five millimeters per second, which produces the familiar small and large box scaling. Fifty millimeters per second is a fast speed used for some pediatric or fast-rhythm recordings. It is not the routine adult standard, and small box and large box values change accordingly when this speed is used. One hundred millimeters per second is far faster than any routine setting. Such a speed would stretch waveforms unrecognizably, and the routine standard remains twenty-five millimeters per second for adults.

Correct Answer: AV junction, forty to sixty

When the SA node fails, the AV junction takes over as the backup pacemaker at forty to sixty beats per minute. If both fail, the ventricular Purkinje system escapes at twenty to forty beats per minute. Bundle branches do not have a typical pacemaker rate of thirty per minute. The hierarchy is SA, then AV junction, then ventricular Purkinje at twenty to forty, with bundle branches being conduction structures rather than primary pacemakers. Purkinje fibers fire at twenty to forty per minute, not one hundred. They are the slowest backup, not the next-in-line backup, which is the AV junction at forty to sixty beats per minute on the standard hierarchy. The right atrium itself does not fire automatically except through the SA node. Ectopic atrial pacemakers do not have a defined ninety-per-minute rate, and the standard backup is the AV junction at forty to sixty.

Correct Answer: Sinus bradycardia within normal intervals

Sinus bradycardia at 50 with normal PR interval, narrow QRS, and 1:1 P-to-QRS ratio fits the profile. The PR is not prolonged, so first-degree block is not present, and the rhythm is regular sinus rather than junctional. Junctional escape rhythm has absent or inverted P waves with short or no PR interval. Upright P waves with normal PR rule out junctional origin, so this label does not match the rhythm described in the scenario. First-degree AV block requires a PR interval over 0.20 seconds. The PR is normal at 0.18 seconds, so first-degree block is not present in this scenario, and the rhythm is sinus bradycardia rather than block. Sinus arrest involves long pauses without QRS or P-wave activity. The rhythm described is regular and ongoing rather than punctuated by pauses, so sinus arrest does not match the strip presentation in this scenario.

Correct Answer: Performing exercise stress testing

Wellens' syndrome indicates critical proximal LAD stenosis, and exercise stress testing can precipitate massive anterior MI. These patients go directly to cardiac catheterization. Stress testing is specifically contraindicated until the lesion has been addressed through revascularization. Recording serial EKGs is appropriate to track changes over time. The contraindicated test is stress testing, not the safe non-invasive serial EKG monitoring that helps the team identify dynamic changes in the patient. Drawing serial troponins is part of standard ACS evaluation. The labs help risk-stratify and rule in or rule out infarction, and they do not provoke the lesion the way exercise stress testing would. Aspirin is part of the antiplatelet therapy in ACS and is appropriate for a Wellens' pattern. Holding aspirin would be harmful, while the contraindicated intervention is exercise stress testing, not antiplatelet therapy.

Correct Answer: One hundred fifty beats per minute

Atrial flutter at three hundred per minute with 2:1 conduction produces a ventricular rate of one hundred fifty per minute. A 4:1 ratio would produce seventy-five, and 3:1 would produce one hundred per minute respectively. Seventy-five per minute corresponds to a 4:1 conduction ratio, not 2:1. With 2:1 conduction, every other flutter wave conducts, producing a faster ventricular rate of one hundred fifty per minute. Three hundred per minute is the atrial rate, not the ventricular rate. The AV node filters most flutter waves, so the ventricular rate is some fraction of three hundred depending on the conduction ratio. Sixty per minute is far slower than the conduction ratios from atrial flutter at three hundred would produce. The 2:1 ratio yields one hundred fifty, and even higher ratios such as 4:1 yield seventy-five rather than sixty.

Correct Answer: Defibrillate immediately

Fine V-fib is shockable. The team defibrillates immediately, then resumes CPR for two minutes before reanalyzing the rhythm. Epinephrine is given after the first shock; advanced airway is placed when feasible without interrupting compressions. Epinephrine is given after the first shock in shockable arrest, not before. Defibrillation is the priority for V-fib, and the medication follows the initial shock as part of the cycle of two minutes of compressions. Advanced airway placement is integrated into the resuscitation but does not take priority over defibrillation in V-fib. The rhythm is shockable, and the immediate next step is the shock followed by resumed compressions for two minutes. Resuming CPR before delivering the shock wastes the rhythm-analysis window. The pads are attached and analyzing, so the next step is the shock, with CPR resumed immediately afterward without further delay.