ACLS review: Pulseless VF/VT part 3

A Word about Transthoracic Resistance

·         Energy level

·         Electrode size

·         Number and times between shocks

·         Distance between electrodes

·         Electrode contact pressure

·         Use of conduction gels

Note:  Successful defibrillation depends on delivery of adequate electrical current to the heart; one of the major determinants of current flow is transthoracic resistance (TTR).  Firmer contact pressure caused TTR to decrease. Thus, human TTR varies widely and is related most closely to chest size. TTR declines only slightly with a second shock at the same energy level. More substantial reductions in TTR and declines only slightly with a second shock at the same energy level. More substantial reductions in TTR and increases in current flow can be achieved by using large paddles and applying firm paddle contact pressure.


Paddle Placement

·         Avoids pacemakers and ICDs

·         Avoid medication patches

·         Avoid letting paddles touch

·         Apex-anterior position

·         Anterior-posterior position

 

Secondary Survey

•       Intubate

•       Secure airway device.

•       IV access

•       If IV access delayed- repeat defibrillation and continue CPR

Note: Once an advanced airway (eg, endotracheal tube, esophageal-tracheal combitube [Combitube], laryngeal mask airway [LMA]) is placed, 2 rescuers no longer deliver cycles of compressions interrupted with pauses for ventilation. Instead, the compressing rescuer should deliver 100 compressions per minute continuously, without pauses for ventilation. The rescuer delivering the ventilations should give 8 to 10 breaths per minute and should be careful to avoid delivering an excessive number of ventilations

Ways of Confirming ET Tube Placement

•      Direct cord visualization

•      End-tidal CO2 monitor

Purple- problem

Yellow- yes                                

Tan- think about it

•      Bilateral breath sounds

•      CXR

•      Continuous waveform capnography

Note:  Continuous waveform capnography is the most reliable method of confirming and monitoring correct placement of an endotracheal tub

Continuous Waveform Capnography

·         Persistently low PETCO2 values (<10 mm Hg) during CPR in intubated patients suggest that ROSC is unlikely

·         If PETCO2 is <10 mm Hg, it is reasonable to consider trying to improve CPR quality by optimizing chest compression parameters

Note:  Although a PETCO2 value of <10 mm Hg in intubated patients indicates that cardiac output is inadequate to achieve ROSC, a specific target PETCO2 value that optimizes the chance of ROSC has not been established. Monitoring PETCO2 trends during CPR has the potential to guide individual optimization of compression depth and rate and to detect fatigue in the provider performing compressions

Reviwed 2/28/16