ROSC – Return of Spontaneous Circulation

What is ROSC?

ROSC (or the return of spontaneous circulation) is the resumption of sustained perfusing cardiac activity associated with significant respiratory effort after cardiac arrest.

Signs of ROSC include moving, coughing, or breathing, along with signs of a palpable pulse or a measurable blood pressure. Both cardiopulmonary resuscitation and defibrillation increase the chances of a patient experiencing ROSC.

While the return of circulation is a favorable sign, it does not predict or indicate a favorable long-term outcome, as many patients have died not long after their circulation has returned.

ROSC can be delayed and occur after failed cardiopulmonary resuscitation efforts have ended, which is also known as the Lazarus phenomenon. Therefore, passive monitoring is recommended for 10 minutes after resuscitation attempts have stopped.

ROSC and Post Cardiac Arrest Care

Post cardiac arrest care is crucial after a patient achieves ROSC. Therefore, healthcare institutions must implement a comprehensive and multidisciplinary system of care universally and consistently for the treatment of post-cardiac arrest patients to assure the very best of outcomes.

This post-cardiac arrest system of care should include:

• Targeted temperature management (TTM)
• Hemodynamic and ventilation optimization
• Immediate coronary reperfusion
• Percutaneous coronary intervention (PCI) for eligible patients
• Neurological care and prognostication
• Other structured interventions

Post Cardiac Arrest Syndrome

Patients who have experienced ROSC after cardiac arrest, regardless of the setting, have a complex combination of pathophysiological processes that are described as post-cardiac arrest syndrome. Examples of post-cardiac arrest syndrome include the following:

• Post arrest brain injury
• Post arrest myocardial dysfunction
• Systemic ischemia
• Reperfusion response
• Persistent, acute, and chronic pathologies that may have participated in the cardiac arrest itself

ROSC and the Importance of Diagnosing and Treating Underlying Causes

Cardiac arrest will sometimes be caused by an underlying and potentially reversible condition. If ACLS providers can quickly identify a specific condition that is causing or contributing to the patient’s cardiac arrest and correct it, the patient may be able to achieve ROSC. Identifying underlying causes is of particular importance in cases of PEA and asystole.

When ACLS providers search for underlying causes, they should do the following:

• Consider the H’s and T’s
• Analyze the ECG for clues to any underlying cause
• Recognize signs of hypovolemia
• Recognize signs of drug overdose or poisonings

If a patient begins showing signs of ROSC, post-cardiac arrest care should be initiated immediately.

How to Improve the Chances of ROSC

The importance of high-quality CPR cannot be overstated for all patients experiencing a cardiac emergency, and this includes minimizing interruptions once CPR has been initiated.

CPP is aortic relaxation pressure minus right atrial relaxation pressure. During CPR, CPP correlates with both myocardial blood flow and ROSC. In one human study, ROSC did not occur unless a CPP 15 mm Hg or greater was achieved during CPR.

This relationship of high-quality CPR to coronary perfusion pressure (CPP) demonstrates the need to minimize interruptions in chest compressions.

It’s also important to resume CPR while the defibrillator is charging. Shortening this interval between the last compression and the shock by just a few seconds can improve the patient’s chances of achieving ROSC. Therefore, healthcare providers must practice efficient coordination between CPR and defibrillation to minimize the hands-off interval between stopping compressions and administering the shock.

Healthcare providers should also consider giving antiarrhythmic drugs, either before or after administering a shock. Amiodarone is typically the first antiarrhythmic agent given in cardiac arrest because it has been clinically demonstrated to improve the rate of ROSC and hospital admission in adults with refractory VFib/pulseless V-tach.

However, if amiodarone is not available, healthcare providers can administer lidocaine instead. And finally, epinephrine is a commonly used drug in resuscitation efforts but its effects on ROSC are questionable. Epinephrine administration seems to improve the chances for ROSC and hospital admission rates. However, large studies have not been conducted to evaluate whether survival is improved.

Lastly, proper chest compressions can also increase the patient’s chances of achieving ROSC. PETCO2, CPP, and SCVO2 correlate with cardiac output and myocardial blood flow during CPR. When chest compressions fail to achieve identified threshold values, ROSC is rarely achieved.

The main determinant of PETCO2 during CPR is blood delivery to the lungs. Persistently low PETCO2 values less than 10 mm Hg during CPR in intubated patients is a good indicator that achieving ROSC will be unlikely.