«Good evidence exists in an animal model that interruption of chest compressions reduces the effectiveness of resuscitation»
If a last choice, endotracheal administration should be administered at 2-2.5 times the IV dose (epinephrine, vasopressin, lidocaine).
MONITORING DURING RESUSCITATION Monitoring during resuscitation using physiologic parameters such as central venous oxygen saturation may confirm effective resuscitation. Pulse checks can verify effective chest compressions, but are unreliable even in trained hands to detect ROSC. End-tidal CO2
most likely atrial or nodal and most wide complex are ventricular in origin. If narrow complex in an unstable patient, the intervention is synchronized is cardioversion. For stable narrow complex, the first choice is adenosine. If unsuccessful or recurrent, calcium channel blockers or beta blockers are indicated. If wide complex and stable, amiodarone or a beta blocker is indicated, and adenosine is specifically contraindicated. Wide complex tachycardia in an unstable patient should always be treated as if pulseless ventricular tachycardia or ventricular vibrillation.
is considered
a good indicator of effective resuscitation. Conversely, persistent low end-tidal CO2 correlates with low probability of ROSC. Pulse oximetry is considered unreliable
during cardiac arrest, although it can be an indicator of ROSC. Blood gas analysis is not real-time for the metabolic state during resuscitation, although sustained extreme hypoxemia or hypocapnia correlate with poor prognosis. Monitoring of volume status may
identify hyovolemia and guide fluid replacement. Fluid boluses should only be employed for indications.
BRADY AND TACHYARRHYTHIA The 2010 Guidelines define unstable as a situation where organ perfusion is compromised, or cardiac arrest is imminent or inevitable. Symptomatic is defined as an arrhythmia results in palpitations, dizziness or dyspnea in a hemodynamically stable patient. For bradycardia with symptoms, the
first line treatment is atropine in a patient with adequate ventilation. If not successful, beta agonists (dopamine, epinephrine) are indicated, with transcutaneous pacing as an alternative when available. For tachycardia with an unstable patient,
the initial response is cardioversion, with sedation if the patient is conscious. If stable, a distinction between narrow and wide complex determines the intervention. Narrow complex tachyarrythmia are
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STRATEGIES TO IMPROVE OUTCOMES Although CPR has been proven effective, the outcome of resuscitation has not achieved the success that could be expected. Although 1/3 of the out of hospital arrest events have some kind of bystander initiated CPR, the overall quality survival is estimated at less than 10%. Although CPR training has been simplified, there is still reluctance to intervene because of personal concerns about mouth-to- mouth ventilation. Telephone-assisted CPR may be a pathway to improve participation
until trained EMS personnel arrive. Even more interesting is the data that CPR without attempts at mouth-to-mouth ventilation achieved better survival rates than those with bystander mouth-to-mouth added. The survival from out-of-hospital Vtach/Vfib undoubtedly has improved with the increasing availability of AEDs, including mandates for specific placement in schools, shopping malls and exercise facilities. Protocols that require continuous chest compression without interruption by first responders may also improve survival. Within medical centers, outcome varies by the time of day and day of the week, with night and weekend survival being lower. This suggests a role for dedicated rapid response teams to improve clinical care, although the benefit could not be demonstrated. Early evidence suggests that hyperoxia in the period immediately after spontaneous return of circulation after resuscitation adversely influences outcome and that adverse outcome may correlation with BIS values that go to zero and remain there. ■
AH
REFERENCES References available on request (
magazine@iirme.com)
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