Pulseless Flashcards

VF and Pulseless VT are shockable rhythms

Answer: TRUE

Ventricular Fibrillation (VF) and Pulseless Ventricular Tachycardia (VT) are indeed shockable rhythms in Advanced Cardiac Life Support (ACLS). These rhythms represent chaotic electrical activity in the heart that prevents effective pumping of blood, leading to cardiac arrest. Defibrillation, which delivers an electrical shock, is the definitive treatment to reset the heart's electrical activity and restore a perfusing rhythm.

VF may be stopped by the initial shock, however if the arrhythmia returns later on during resuscitation:

Answer: Continue to deliver shocks with the same level of force that worked before.

If Ventricular Fibrillation (VF) recurs after an initial successful defibrillation, the ACLS guidelines recommend delivering further shocks. The appropriate action is to continue with shocks, typically at the same energy level that was previously effective, while also continuing CPR and administering medications as per the cardiac arrest algorithm. The goal is to promptly terminate the life-threatening arrhythmia.

How much does the chance of survival from an observed VF sudden cardiac arrest drop for each minute that goes between collapse and defibrillation if no bystander CPR is given?

Answer: 7% to 10%

For every minute that passes without defibrillation after an observed Ventricular Fibrillation (VF) sudden cardiac arrest, the chance of survival decreases significantly, typically by 7% to 10% if no bystander CPR is provided. This rapid decline underscores the critical importance of early defibrillation and immediate high-quality CPR to improve patient outcomes. Time is muscle and brain in cardiac arrest.

Pulse checks ought to:

Answer: Be carried out only if there is an orderly rhythm during rhythm analysis.

In the context of cardiac arrest resuscitation, pulse checks should be brief and performed only when an organized rhythm is observed on the cardiac monitor. If the rhythm is chaotic (like VF/pulseless VT) or asystole, there is no need for a pulse check as it's assumed there's no effective circulation. Prolonged pulse checks interrupt crucial chest compressions, which are vital for maintaining blood flow.

What is the first-line antiarrhythmic medication administered in cardiac arrest?

Answer: Amiodarone

In the ACLS algorithm for shockable rhythms (VF/pulseless VT) that persist after defibrillation and epinephrine, Amiodarone is the first-line antiarrhythmic medication. It is administered to help stabilize the heart's electrical activity and prevent the recurrence of life-threatening arrhythmias. Lidocaine is an alternative if amiodarone is unavailable or contraindicated, but Amiodarone is preferred.

The heart is restarted through defibrillation.

Answer: FALSE

Defibrillation does not 'restart' a heart that has completely stopped (asystole). Instead, it delivers an electrical shock to depolarize a significant mass of myocardial cells simultaneously, aiming to terminate chaotic rhythms like Ventricular Fibrillation (VF) or pulseless Ventricular Tachycardia (VT). The goal is to allow the heart's natural pacemaker to resume an organized, perfusing rhythm, not to jump-start a flatlined heart.

If a biphasic defibrillator is being used and the dosage is unknown:

Answer: Shock with the highest energy dose possible.

When using a biphasic defibrillator for ventricular fibrillation or pulseless ventricular tachycardia and the specific effective dose is unknown, ACLS guidelines recommend delivering the highest available energy dose. This approach maximizes the likelihood of successful defibrillation, which is critical for terminating life-threatening arrhythmias. It ensures the most potent shock is delivered to restore a perfusing rhythm.

The correct epinephrine dose for VF/pVT is:

Answer: 1 mg IV/IO - repeated every 3 to 5 minutes

The correct dose of epinephrine for cardiac arrest rhythms like ventricular fibrillation (VF) or pulseless ventricular tachycardia (pVT) is 1 mg. This dose should be administered intravenously (IV) or intraosseously (IO) and can be repeated every 3 to 5 minutes during resuscitation efforts. Epinephrine's vasoconstrictive effects are crucial for improving coronary and cerebral perfusion pressure during CPR.

When performing resuscitation, epinephrine is used:

Answer: Because it produces vasoconstriction

Epinephrine is used during resuscitation primarily because it produces systemic vasoconstriction through its alpha-adrenergic effects. This vasoconstriction increases myocardial and cerebral blood flow, thereby improving coronary perfusion pressure and diastolic blood pressure during chest compressions. While it has other effects, its role in cardiac arrest is predominantly to enhance blood flow to vital organs.

The ideal chest compression fraction is:

Answer: As high as possible

The ideal chest compression fraction, which is the proportion of time spent performing chest compressions during a resuscitation attempt, should be as high as possible. ACLS guidelines emphasize minimizing interruptions to chest compressions, aiming for a fraction of 80% or greater. Continuous, high-quality chest compressions are vital for maintaining blood flow to the brain and heart, directly impacting patient survival.

The two most frequent causes for pulseless electrical activity are what?

Answer: Hypovolemia and hypoxia

The two most frequent and reversible causes of pulseless electrical activity (PEA) are hypovolemia and hypoxia. These are part of the 'H's and T's' mnemonic for reversible causes of cardiac arrest. Hypovolemia leads to insufficient blood volume and cardiac output, while hypoxia impairs myocardial function and cellular metabolism, both leading to ineffective cardiac pumping despite electrical activity.

A definition of pulseless electrical activity is:

Answer: Any organized rhythm without a pulse

Pulseless electrical activity (PEA) is defined as any organized cardiac electrical activity observed on an ECG monitor, but without a palpable pulse. This means the heart's electrical system is generating impulses, but the mechanical pumping action is either absent or too weak to produce a detectable pulse. It is crucial to distinguish PEA from asystole, where there is no electrical activity.

Which of the following does not constitute a justification for ceasing or delaying resuscitative measures?

Answer: Resuscitation effort have been unsuccessful for 20 minutes or more

While prolonged resuscitation efforts without success can lead to consideration of termination, a specific duration like '20 minutes or more' is not an absolute, standalone justification for ceasing or delaying resuscitative measures. Definitive reasons for ceasing or delaying resuscitation include rigor mortis, valid do-not-attempt-resuscitation (DNAR) orders, or immediate threats to the safety of providers. The decision to terminate resuscitation is complex and multifactorial.

Routine insertion of an advanced airway in asystole:

Answer: Should only be carried out if ventilations with a BVM are unsuccessful.

In asystole, the priority is high-quality chest compressions with minimal interruptions. Routine insertion of an advanced airway is not recommended as a primary intervention and can cause detrimental pauses in compressions. A bag-valve-mask (BVM) provides adequate ventilation, and an advanced airway should only be considered if BVM ventilation is ineffective or prolonged resuscitation is anticipated, ensuring minimal interruption to CPR.

Which of the ensuing statements is untrue?

Answer: Only the therapies listed in the algorithm are used to treat PEA.

The statement 'Only the therapies listed in the algorithm are used to treat PEA' is untrue. While the ACLS algorithm provides a structured approach for PEA, effective treatment heavily relies on identifying and treating the underlying reversible causes (the H's and T's). These underlying causes, such as hypovolemia or hypoxia, require specific interventions beyond just the medications listed in the algorithm.

Which of the ensuing assertions is accurate?

Answer: There is no evidence to support the use of "defibrillation" to treat asystole.

There is no evidence to support the use of defibrillation to treat asystole. Asystole is characterized by the absence of electrical activity on the ECG, appearing as a flat line. Defibrillation delivers an electrical shock to reset chaotic electrical activity (like VF or pVT), but it is ineffective and not indicated for asystole because there is no electrical activity to 'defibrillate.' The focus for asystole is on high-quality CPR and identifying reversible causes.