When comparing monophasic and biphasic defibrillators, all of the following statements are correct regarding biphasic defibrillators EXCEPT:
Answer: D: Biphasic waveforms are more effective at terminating ventricular arrhythmias at lower energy levels, have demonstrated greater first-shock efficacy than monophasic waveforms, and have greater first shock efficacy for long duration VF/VT. However, no randomized studies have demonstrated superiority in terms of neurologically intact survival to hospital discharge. Biphasic waveforms have been shown to be superior to monophasic waveforms for elective cardioversion of atrial fibrillation, with greater overall success rates, using less cumulative energy and reducing the severity of cutaneous burns, and therefore biphasic is the waveform of choice for this procedure.
References:
A 63-year-old male suffered a VF cardiac arrest and the first shock was delivered on arrival in the emergency department (ED). After a further 2 minutes of CPR, he was noted to be still in VF on the monitor.
What is the next MOST appropriate step to take?
Answer: C: The treatment of VF is defibrillation. The initial shock should be delivered at 200 J followed by 2 minutes of CPR. If the patient remains in VF after 2 minutes of good-quality CPR, a second shock should be delivered. For second and subsequent biphasic shocks the same initial energy level is acceptable but an increased energy level may be used. During CPR, adrenaline should only be given after the second shock and amiodarone after the third shock if VF is resistant to defibrillation. A pulse should only be checked if there is an organised rhythm present on the monitor.
A 70-year-old male suffered an out-of-hospital cardiac arrest (OHCA). On arrival in the ED CPR is in progress and a laryngeal mask airway (LMA) is in situ. IV access was not obtained pre-hospital. The initial rhythm on arrival in the ED showed a pulseless electrical activity (PEA) at 30 bpm.
What is the MOST appropriate next step to be performed?
Answer: A: The aims of resuscitation in patients with cardiac arrest in a non-shockable rhythm are the provision of good-quality CPR and the search for reversible causes. The use of adrenaline has been shown to increase ROSC, but no resuscitation drugs or advanced airway interventions have been shown to increase survival to hospital discharge after cardiac arrest. Atropine is no longer recommended for routine use during pulseless electrical activity (PEA). The administration of medication via the tracheal route is also no longer recommended – if IV access cannot be obtained, IO access should be achieved and drugs administered via this route.
Reference:
Regarding the use of vasopressors during cardiac arrest in adults with a shockable rhythm, which ONE of the following is TRUE?
Answer: D: Two studies (LOE1) reported improvement in ROSC with high-dose adrenaline. However, there are no studies that demonstrate a survival benefit compared with standard dose adrenaline. Currently, high-dose adrenaline is not recommended in the guidelines due to the lack of survival benefit and potential harmful effects (tachyarrythmias and hypertension after resuscitation).
There is some evidence to suggest that vasopressors (adrenaline and vasopressin) may improve ROSC and short-term survival. At the same time, there is insufficient evidence to suggest that vasopressors improve survival to hospital discharge and neurological outcome. Current guidelines recommend that the use of vasopressors may be considered in adult cardiac arrest given the observed benefit in short-term outcomes. There is also insufficient evidence to suggest the optimal dosage of any vasopressor in the treatment of adult cardiac arrest. ILCOR, as well as ARC, recommend 1 mg of adrenaline, after initial counter shocks have failed (after second shock and then every second cycle).
Three studies (LOE1) and a meta-analysis (LOE1) demonstrated no difference in outcomes (ROSC, survival to discharge, and neurological outcome) with vasopressin compared with adrenaline as first-line pressor in cardiac arrest and the use of either is acceptable.
A 30-week pregnant female suffers a cardiac arrest. Which ONE of the following statements is TRUE?
Answer: C: Current resuscitation guidelines acknowledge that research in the area of maternal resuscitation is lacking. Despite this, it is recommended that a peri-mortem caesarean should be considered early in maternal cardiac arrest if the fetus is of viable age. Prognosis for the intact survival of infant is best if delivery occurs within 5 minutes of maternal arrest; however, if the 5-minute time frame is exceeded, a caesarean section should still be considered. One systematic review of peri-mortem caesarean sections suggested that it may have improved maternal and neonatal outcomes. At older gestational age (30–38 weeks) infant survival was possible even when delivery was after 5 minutes from the onset of maternal cardiac arrest.
There are no RCTs evaluating the effect of specialized obstetric resuscitation versus standard care in post-arrest pregnant women and all recommendations are based on the important physiological changes that occur in pregnancy that may influence treatment recommendations and guidelines for resuscitation of cardiac arrest in pregnancy. There is no evidence to support that aorta-caval decompression improves maternal hemodynamics and fetal wellbeing in pregnant women suffering from cardiac arrest. The evidence is also conflicting in non-arrest literature. Despite the lack of evidence, it should still be considered. There is some evidence that manual left uterine displacement is as good as or better than left lateral tilt.
There is insufficient evidence to support or refute the use of post cardiac arrest hypothermia. A single case report suggests that post cardiac arrest hypothermia was used safely and effectively in early pregnancy.
Click to expand