ACLS Principles Flashcard 10
Rationale
C. Rationale: This rhythm is VF, which is a shockable rhythm. Thus, the correct action is asynchronous defibrillation. (ACLS Case: Cardiac Arrest algorithm)
Question
The patient with the following rhythm has no pulse and no respirations. He is attached to a biphasic monitor. The first step in treatment is:
a. Give epinephrine
b. Give atropine
c. Defibrillate
d. Do synchronized cardioversion
Answer
c. Defibrillate
Rationale
A. Rationale: Studies have shown that in cases of pulmonary embolism, mechanical thrombectomy restores pulmonary perfusion in 85% of patients.
Question
The physician in charge of a cardiac arrest patient with a massive pulmonary embolism in the right main pulmonary artery is deciding to perform a percutaneous mechanical thrombectomy while the patient is undergoing cardiopulmonary resuscitation. Mechanical thrombectomy restores pulmonary perfusion in what percentage of patients?
a. 85%
b. 100%
c. 50%
d. 75%
Answer
a. 85%
Rationale
C. Rationale: Epinephrine should be administered as soon as possible after a nonshockable rhythm (asystole or PEA) is identified by the team. This should be followed by immediate CPR to circulate the drug.
Question
The recommendation for epinephrine administration for cardiac arrest in the presence of asystole is:
a. Epinephrine is no longer recommended for asystole.
b. Epinephrine should be administered after the initial defibrillation.
c. Epinephrine should be administered as soon as available after asystole is recognized.
d. Epinephrine should be administered via the ET tube after intubation.
Answer
c. Epinephrine should be administered as soon as available after asystole is recognized.
Rationale
D. Rationale: The correct rate, quality of chest compressions, and lower duration of interruptions in chest compressions determine the success of ROSC.
Question
The success of ROSC following cardiac arrest is aided by:
a. Chest compressions at a rate of > 120 per minute
b. Compression to ventilation ratio of 15:2
c. Limiting involvement of community members
d. Very limited interruptions of chest compressions
Answer
d. Very limited interruptions of chest compressions
Rationale
C. Rationale: Studies show that a majority of cardiac arrest patients are not provided with high-quality cardiopulmonary resuscitation (CPR), and as a consequence, the survival rate of out-of-hospital cardiac arrest is only 10.4%, while the survival rate of in-hospital cardiac arrest is only 25.8%.
Question
The survival rate of in-hospital cardiac arrest is:
a. 10.4%
b. 15.8%
c. 25.8%
d. 50%
Answer
c. 25.8%
Rationale
A. Rationale: One must learn to identify if the patient has achieved a return of spontaneous circulation. An organized rhythm without a pulse is pulseless electrical activity, which is still classified as a cardiac arrest rhythm.
Question
The team has been resuscitating a 45-year-old man with cardiac arrest in asystole. He was brought to the emergency department in cardiac arrest after being involved in a vehicular crash. You identified the cause as cardiac tamponade, and the team promptly performed an emergency pericardiocentesis. After 12 minutes of resuscitation, you would like to evaluate for a return of spontaneous circulation because the recent rhythm check has recorded the following ECG tracing:
Which one of the following choices is NOT a definite indicator of ROSC?
a. An organized sinus rhythm on ECG
b. The presence of pulse and blood pressure
c. An abrupt increase in end-tidal CO2 > 40 mm Hg
d. Intra-arterial monitoring representing spontaneous arterial pressure waves
Answer
a. An organized sinus rhythm on ECG
Rationale
B. Rationale: Waveform capnography indicates the quality of CPR. If it measures < 10 mm Hg, CPR must be improved. The team must check for adequate chest compressions and compression and ventilation rates, chest recoil, ET tube placement, and minimize interruptions in compressions.
Question
The team has been resuscitating a 71-year-old man in cardiac arrest with pulseless electrical activity for 10 minutes. He is intubated with an intravenous line in place. A defibrillator is connected, and the following ECG tracing is recorded:
Vital signs: HR = 0 bpm, BP = 0 mm Hg, RR = manually ventilated, T = 36°C, oxygen saturation = 79%, waveform capnography = 6 mm Hg. Given these metrics, what should the team do to improve the patient’s chances of achieving return of spontaneous circulation?
a. Increase the ventilation rate
b. Improve CPR quality
c. CPR is futile; suggest discontinuing resuscitative efforts
d. Epinephrine IV injections are inadequate
Answer
b. Improve CPR quality
Rationale
C. Rationale: As impulses travel from the sinoatrial node to the atrioventricular node, the ventricles contract after allowing the atrium to relax for about 100 milliseconds. This impulse is reflected in the ECG as the QRS complex.
Question
What cardiac stage is represented by the QRS complex?
a. Atrial contraction
b. Atrial relaxation
c. Ventricular contraction
d. Ventricular relaxation
Answer
c. Ventricular contraction
Rationale
A. Rationale: Defibrillation does not restart the heart. The goal of defibrillation is to stun the heart and halt all electrical impulses from within. This allows viable myocardium to activate its pacemakers to produce normal electrical activity to maintain a perfusing rhythm.
Question
What does defibrillation do to the heart?
a. Stuns the heart
b. Restarts the heart
c. Produces a positive inotropic effect in the heart
d. Produces a positive chronotropic effect in the heart
Answer
a. Stuns the heart
Rationale
C. Rationale: Studies have shown that when epinephrine is given within 2 minutes after a shock that has successfully terminated a shockable cardiac arrest rhythm, the chances of survival decreases. This can be due to the effects of epinephrine with beta-adrenergic receptors that increase the heart’s oxygen demand.
Question
What happens if epinephrine is given right after a shock that has successfully terminated the shockable cardiac arrest rhythm?
a. It enhances the cardiac output.
b. It improves survival rate.
c. It will have a detrimental effect on cardiovascular function.
d. No significant effect will occur.
Answer
c. It will have a detrimental effect on cardiovascular function.