In a patient undergoing cardiac arrest, what are the immediate management steps and when should vascular access (peripheral intravenous or intra‑osseous line) be placed?

Immediate Management of Cardiac Arrest: What Needs to Be Done and When to Place a Line

Begin high-quality chest compressions immediately at 100-120 compressions per minute with a depth of 5-6 cm, and establish vascular access (peripheral IV or intraosseous line) during CPR after initiating compressions and attempting defibrillation for shockable rhythms—never delay compressions or defibrillation to obtain IV/IO access. 1, 2

Initial Actions (First 30-45 Seconds)

• Start chest compressions within seconds of recognizing cardiac arrest, maintaining at least 100-120 compressions per minute at 5-6 cm depth with full chest recoil between compressions 2, 1
• Apply defibrillator pads immediately and analyze rhythm without pausing compressions to identify shockable rhythms (VF/VT) versus non-shockable rhythms (asystole/PEA) 2, 1
• Deliver rapid defibrillation sequence of 200 J, 200 J, then 360 J within 30-45 seconds for VF/VT, resuming CPR immediately after each shock 1
• Use compression-to-ventilation ratio of 30:2 until an advanced airway is placed, then switch to continuous compressions with 10 breaths per minute 2, 1

Timing of Vascular Access

Vascular access should be obtained during CPR, not before it—this is a secondary priority after compressions and defibrillation. 1

• Establish IV or IO access after beginning CPR and attempting defibrillation, performing this without interrupting chest compressions 1
• If sufficient rescuers are present, one team member obtains vascular access while others continue compressions and prepare for defibrillation 1
• The primary purpose of IV/IO access is drug delivery—epinephrine and antiarrhythmics 1

Preferred Access Routes (in order)

1. Peripheral IV is acceptable if already present or easily obtained without interrupting CPR 1
2. Intraosseous (IO) access provides equivalent drug delivery to peripheral IV and should be used when peripheral access is difficult 1
3. Central venous access delivers drugs most efficiently but should NOT be attempted during active resuscitation due to risks (pneumothorax, arterial puncture) and time required—only use if already in place 1

Drug Administration Timing

• Give first dose of epinephrine 1 mg IV/IO every 3-5 minutes starting after the initial defibrillation attempts 1, 2
• For VF/VT, administer epinephrine after the third shock in the sequence 2
• For asystole/PEA, give epinephrine as soon as IV/IO access is established 1, 3
• Follow each peripheral IV drug with a 20-50 mL saline flush and briefly elevate the extremity to facilitate central circulation delivery 1

Airway Management Timing

• Secure advanced airway (endotracheal intubation) promptly but never delay chest compressions to attempt intubation 2, 1
• Brief intubation attempts should occur during CPR cycles, ideally by a second rescuer 1
• Once advanced airway is placed, deliver 10 breaths per minute during continuous compressions without pauses 2, 1

Critical Pitfalls to Avoid

• Never delay compressions or defibrillation to establish IV/IO access—these are the primary life-saving interventions 1, 2
• Do not attempt central line placement during active resuscitation unless you are highly skilled and it will not interrupt CPR 1
• Limit all interruptions in chest compressions to <10 seconds, including for rhythm checks and shock delivery 2, 1
• Rotate the compressor every 2 minutes to prevent fatigue and maintain compression quality 2, 1
• Do not use endotracheal drug administration as first-line—it has unpredictable absorption and requires 2-3 times the IV dose 1

Algorithm for Non-Shockable Rhythms (Asystole/PEA)

• Continue high-quality CPR while establishing IV/IO access 1, 3
• Administer epinephrine 1 mg IV/IO every 3 minutes 1, 3
• Search for and treat reversible causes (4 H's and 4 T's): Hypoxia, Hypovolemia, Hydrogen ion (acidosis), Hypo/hyperkalemia, Hypothermia, Tension pneumothorax, Tamponade, Thrombosis (PE/MI), Toxins 1, 4
• Reassess rhythm every 2 minutes—if VF/VT develops, switch to defibrillation algorithm 1, 3

Special Considerations

• In pediatric arrests, obtain IO/IV access during Step 4 (after initial defibrillation sequence) if sufficient rescuers are present 1
• For in-hospital arrests with continuous invasive monitoring already present, use existing central lines for drug delivery 1
• Point-of-care ultrasound can identify reversible causes (tamponade, PE, hypovolemia) but should not interrupt compressions 4