ACLS review: Pulseless VF/VT Review questions Part 4

Pulseless VF/VT Review Questions Part 4

31.  What are the initial and subsequent joule settings when defibrillating a patient with a monophasic defibrillator?

32.  In order to maintain rescuer safety, should CPR be interrupted while the defibrillator is charging?

33.  Biphasic defibrillators are effective at terminating VT over a variety of joule settings.  If you do not know the manufacturer’s effective biphasic dose setting, what joule setting should you use?

34.  What should you do if VF is terminated by a shock but later recurs in the resuscitation attempt?

35.  After delivering a first shock at 200 J, you note that the patient remains in refractory VF.  What should you do next?

36.  What should the rescuer do as he/she is clearing the patient prior to delivering a shock?

37.   Why is it necessary to use conductive gels when using defibrillator paddles?

38.  When treating a cardiac arrest patient, when should pulse checks be performed? 

39.  What two vasopressors drugs are recommended in the treatment of pulseless VF/VT?

40.  What are the therapeutic effects of epinephrine and vasopressin during a pulseless arrest?

Answers

31.  If you are using a monophasic defibrillator, give an initial single 360-J shock and use the same energy setting for subsequent shocks.

32.  No.  Continue CPR while the defibrillator is charging and continue until told to “clear” the patient.  Even a 5-10 second pause in chest compressions reduces the chance that a shock will terminate VF/VT to a profusing heart rhythm.

33.  If you do not know the manufacturer’s effective biphasic dose setting then deliver 200 J for the first shock and an equal or higher joule setting for subsequent shocks.

34.  If VF recurs later in the resuscitation attempt then deliver subsequent shocks at the previous successful energy level.

35.  Immediately after the first shock, resume CPR, beginning with chest compressions.  Give 2 minutes of CPR (about 5 cycles).  In the patient without an advanced airway, a cycle of CPR consists of 30 compressions followed by 2 ventilations.

36.  The person operating the defibrillator should make a visual check to ensure that no one is touching the patient or stretcher. 

37.   Conductive materials are used to reduce transthoracic resistance (resistance to the electrical current).  Conductive materials include electrode gels or pastes or gel pads.  Also remember to maintain firm downward pressure of the paddles to ensure adequate skin to paddle contact.

38.  Ideally pulse checks should be performed during the rhythm analysis.  If an organized rhythm is noted on the monitor during the rhythm analysis, then a team member should palpate the patient for a pulse.   This ideally should take no more than 10 seconds.  If there is any doubt about the presence of a pulse, then resume CPR

39. Epinephrine 1mg IV/IO- may repeat every 3-5 minutes

Vasopressin 40 U IV/IO- may substitute for the first or second dose of epinephrine.

40.  Epinephrine is use during resuscitation primarily for its alpha-adrenergic effects which lead to peripheral vascular vasoconstriction.  This increases both cerebral and coronary blood flow during CPR.  Vasopressin is a noradrenergic agent which also causes peripheral vasoconstriction.  Overall, the effects of vasopressin have not been shown to be different from that epinephrine.



Reviewed 2/28/16