PBL

Rebecca Johnson (Kinnard), CA2

Case

59 y/o male presents for a laproscopic cholecystectomy, liver biopsy and RFA with Dr. BuellPMH:

HTNColon Cancer s/p LAR

Physical Exam:80kg, 6’9”Normal airway examAll labs WNL

Case continued…

Entire surgery uneventful...UntilUpon closing patient begins having short 1-2 second ventricular fibrillation-like arrhythmias.

HR 110s-120sAll other VSS

Total of 100mg Lidocaine and 20mg Esmolol givenThey ultimately subside after approximately 5 minutes Cardiology consulted

Troponins x3 negative2D echo: only showed mild MR, otherwise WNL

Case continued…

But let’s pretend….The ventricular fibrillation becomes sustained and BP begins to steadily fall

What do you do?

Case continued…

First steps: Non-pharmacologicalImmediate DefibrillationIdentify underlying cause

What are some of the most common conditions in the OR that predispose

patients to arrhythmias?

HypoxemiaHypercarbiaAcidosisHypotensionElectrolyte imbalancesMechanical irritation 

Pulmonary artery catheter Chest tube

HypothermiaAdrenergic stimulation (light anaesthesia)Proarrhythmic drugsMicro/macro shockCardiac ischemia

What would be your first pharmacological choice for the

treatment of unstable VF?

A. LidocaineB. AmiodaroneC. ProcainamideD. All of the above are equally

efficacious E. None of the above

You are welcome Jud

Answer

BThere are no human clinical studies available to suggest that IV lidocaine promotes the conversion of sustained VT or VF to sinus rhythm in any setting. Recent evidence‐based recommendations by the AHA have therefore changed the recommendation for lidocaine to ‘indeterminate’, below amiodarone and procainamide.

ARREST Trial

Purposetest the hypothesis that amiodarone (300 mg IV) compared to placebo improves the rate of successful cardiac resuscitation after out-of-hospital cardiac arrest

Patient PopulationAdult victims of out-of-hospital cardiac arrest in Seattle504 patients total

Inclusion CriteriaVentricular fibrillation or pulseless ventricular tachycardia persisting after 3 or more precordial shocks

Study DesignRandomized, double-blind, placebo-controlled study

ARREST Trial

ResultsIV amiodarone (300 mg), given after at least 3 precordial shocks during the resuscitation of victims of out-of-hospital cardiac arrest, increases the rate of survival to hospital admission compared to placebo

44% versus 34%, p=0.03

However, the study was underpowered to detect differences in survival to hospital dischargePatients in the amiodarone group were more likely to exhibit hypotension (59% versus 48%, p=0.04) or bradycardia (41% versus 25%, p=0.004)This was the first randomized prospective data to show a short‐term survival advantage to the use of an antiarrhythmic agent during cardiac arrest.

ALIVE Trial

Purposecompare IV amiodarone and lidocaine as an adjunct to defibrillation in victims of out-of-hospital cardiac arrest.

Patient PopulationAdult patients with out-of-hospital cardiac arrest in Toronto347 patients total

Inclusion CriteriaVentricular fibrillation documentedVentricular fibrillation resistant to 3 shocks, at least one dose of IV epinephrine, and a fourth shockVentricular fibrillation recurring after successful initial resuscitation

Study DesignRandomized, double-blind trial of IV amiodarone (5 mg/kg) versus Lidocaine (1.5 mg/kg)

Alive Trial

ResultsAfter treatment with amiodarone:

22.8 percent of 180 patients survived to hospital admission

After treatment with lidocaine:12.0 percent of 167 patients

P=0.009; odds ratio, 2.17; 95 percent confidence interval, 1.21 to 3.83There were no differences between the treatment groups in the proportions of patients who needed treatment of bradycardia with atropine, pressor treatment with dopamine or in the proportions receiving open-label lidocaine.

Which of the following is not true of amiodarone?

A. It slows the SA node.B. It slows AV conduction.C. It decreases the ventricular response to

atrial fibrillation.D. It is a coronary vasodilator, but not a

peripheral vasodilator.E. It can cause both hypotension and

bradycardia

Answer

D. Amiodarone is both a coronary and peripheral vasodilator.

Now onto the new BLS/ACLS updates…

A. Check pulseB. Chest compressions C. CardioversionD. CoolingE. CatheterizationF. All are correct

According to the updated guidelines for CPR from the

AHA, which of the following is not considered one of the “C’s”

of A-B-C?

A. The AHA no longer recommends pulse checks by untrained laypeople.

For trained responders, the interruption of chest compressions to check the victim’s pulse is no longer recommended.

Answer

BLS UpdatesThe old mantra of “A-B-C” has been replaced by “C-A-B”Delay in the start of chest compressions is minimized by placing circulation first. Individuals who are fearful of performing rescue breathing are more likely to start the resuscitation process if they only have to do chest compressions. The “C” in “CAB” is further delineated by the four “Cs” of cardiac arrest care: (1) chest compressions(2) cardioversion and defibrillation(3) cooling (postarrest therapeutic hypothermia)(4) catheterization

No pulse checks If the patient is unresponsive and has no breathing or abnormal breathing, chest compressions should be performed.

“ABC” becomes “CAB”

Circulation is to be addressed first with the initiation of chest compressions. Compression:ventilation ratio of 30:2 should be maintained after the first round of 30 chest compression.

Changes to BLS

Push Hard, Push Fast

(high-quality CPRIs emphasized)

100 compressions/min at a depth of at least 2 inches.

Hands-only CPR for the untrained lay rescuer

Hands-only CPR is easier to perform for those with no training and eliminates the reluctance that individuals may have with rescue breathing.

Changes to BLS

According to the AHA, which of the following is not considered one of the new ACLS updates?

A. Atropine use has been removed from asystole/PEAB. Cricoid pressure is no longer recommended for

routine useC. For symptomatic or unstable bradycardia,

external pacing is now considered more effective than IV infusion of chronotropic drugs when atropine is not effective

D. End-tidal carbon dioxide should be monitored in all intubated patients

E. All are part of the new ACLS updates

C. For symptomatic or unstable bradycardia, intravenous infusion of chronotropic drugs is now recommended as an equally effective alternative to external pacing when atropine is not effective.

Answer

Atropine removed from asystole/PEA

Atropine is no longer recommended for routine use in the management of asystole and PEA arrest.

End-tidal carbon dioxide monitoringof all intubated patients

A new Class 1 recommendation for all adults who are intubated is that they have continuous quantitative waveform capnography for confirmation and monitoring of endotracheal tube placement.

Cricoid pressure is no longer recommended for routine use

The routine use of cricoid pressure during the placement of an endotracheal tube is no longer recommended. Instead, it should be used only to improve visualization of the vocal cords.

Changes to ACLS

Routine use of chronotropic drugsis recommended for bradycardia

For symptomatic or unstable bradycardia, intravenous infusion of chronotropic drugs is now recommended as an equally effective alternative to external pacing when atropine is not effective.

Postresuscitation therapeutic hypothermia

Postcardiac arrest care in those who have not returned to a normal mental status should include the initiation of therapeutic hypothermia to optimize neurologic recovery.

Cardiac catheterization

Patients with return of spontaneous circulation should be considered for urgent cardiac catheterization regardless of whether there is ST-segment elevation on their postresuscitation electrocardiogram. In the field, patients suspected of having acute coronary syndrome should be transported toa facility with reperfusion capabilities.

Changes to ACLS

SummaryNo longer “A-B-C” (airway, breathing, and circulation) but instead “C-A-B” (circulation, airway, and breathing)High-quality chest compressions (100 per minute at a depth of at least 2 in) should be started as soon as possible and continued with minimal interruptions.Interruptions should be limited to rhythm checks or the exchange of providers performing compressions. Defibrillation should be delayed until at least 30 chest compressions have been done. After a patient has been resuscitated, the focus of the providers needs to shift to postresuscitation care, which emphases the maintenance of cardiocerebral perfusion pressure, achieving therapeutic hypothermia, and considering the patient for early cardiac catheterization. The four C’s of CPR (compressions, cardioversion, cooling, and catheterization) are the only interventions that have been shown to improve long-term outcomes.

Figure 2. ACLS Tachycardia Algorithm.

et al. Circulation 2005;112:IV-67-IV-77Copyright © American Heart Association

ACLS Pulseless Arrest Algorithm.

et al. Circulation 2005;112:IV-58-IV-66Copyright © American Heart Association