How do you manage cardiac arrest due to 5H (Hypovolemia, Hypoxia, Hydrogen ions, Hyperkalemia, Hypothermia) and 5T (Tamponade, Tension pneumothorax, Toxins, Thrombosis, Trauma) causes?

Management of Cardiac Arrest Due to 5H and 5T Causes

While performing high-quality CPR and standard ACLS protocols, you must systematically identify and treat reversible causes (the 5H's and 5T's) during each 2-minute CPR cycle, as this is fundamental to successful resuscitation and survival. 1

Immediate Priorities During Cardiac Arrest

High-Quality CPR Must Be Maintained Throughout

• Push hard: at least 2 inches (5 cm) depth 1
• Push fast: 100-120 compressions per minute 1
• Allow complete chest recoil between compressions 1
• Minimize interruptions in compressions to less than 10 seconds 1
• Avoid excessive ventilation 1
• Rotate compressor every 2 minutes or sooner if fatigued 1

Rhythm-Based Management Concurrent with Reversible Cause Treatment

• Check rhythm every 2 minutes 1
• For VF/pulseless VT: deliver shock (biphasic 120-200 J or maximum available), then immediately resume CPR 1
• Establish IV/IO access and administer epinephrine 1 mg every 3-5 minutes 1
• For refractory VF/pulseless VT: amiodarone 300 mg bolus (then 150 mg) or lidocaine 1-1.5 mg/kg 1

Systematic Approach to the 5H's (Reversible Causes)

1. Hypovolemia

• Rapidly infuse IV crystalloids or blood products if hemorrhage is suspected 1
• Consider massive transfusion protocol if trauma or surgical bleeding is present 2
• Establish large-bore IV access or IO access immediately 2

2. Hypoxia

• Administer 100% oxygen immediately 3, 2
• Place advanced airway (endotracheal tube or supraglottic airway) and confirm placement with waveform capnography 1
• Once advanced airway is placed, give 1 breath every 6 seconds (10 breaths per minute) with continuous chest compressions 1
• Use waveform capnography to monitor ET tube placement—PETCO2 <10 mm Hg indicates poor CPR quality 1, 2

3. Hydrogen Ion (Acidosis)

• Ensure adequate ventilation to eliminate CO2 1
• Consider sodium bicarbonate only in specific situations: known severe metabolic acidosis, hyperkalemia, or tricyclic antidepressant overdose 1
• Obtain arterial blood gas if possible to guide therapy 3

4. Hypo-/Hyperkalemia

For Hyperkalemia:

• Administer IV calcium chloride or calcium gluconate immediately—this is Class I recommendation 1
• Give insulin with dextrose to shift potassium intracellularly 1
• Consider sodium bicarbonate if concurrent acidosis 1
• Do NOT administer IV bolus potassium during cardiac arrest, even if hypokalemia is suspected—this causes harm 1

For Hypokalemia:

• Correct gradually after ROSC, not during active arrest 1

5. Hypothermia

• Begin active rewarming measures immediately 1
• Continue resuscitation efforts longer than usual—patients are "not dead until warm and dead" 4
• Standard ACLS medications and defibrillation should still be attempted even in severe hypothermia 4

Systematic Approach to the 5T's (Reversible Causes)

1. Tension Pneumothorax

• Perform immediate needle decompression (2nd intercostal space, midclavicular line) if suspected 1
• Follow with chest tube placement 1
• Suspect in trauma patients, those with recent central line placement, or mechanical ventilation 5

2. Tamponade (Cardiac)

• Perform immediate pericardiocentesis if suspected 1
• In post-cardiac surgery patients, perform emergency resternotomy within 5 minutes if unresponsive to initial resuscitation 6, 7
• Consider point-of-care ultrasound to rapidly identify pericardial effusion 6

3. Toxins

• Administer specific antidotes if toxin is known 1
• For opioid overdose: standard resuscitation takes priority over naloxone administration 2
• For calcium channel blocker or beta-blocker toxicity: consider high-dose insulin therapy and IV calcium 1
• Lipid emulsion therapy may be considered for local anesthetic toxicity 1

4. Thrombosis (Pulmonary)

• Consider thrombolytic therapy (alteplase) for suspected massive pulmonary embolism causing cardiac arrest 1
• Prolonged CPR (>60 minutes) may be necessary while thrombolytics work 5
• Consider extracorporeal CPR (ECPR) if available 6

5. Thrombosis (Coronary)

• Prepare for emergency cardiac catheterization and percutaneous coronary intervention after ROSC 1, 8
• Continue standard ACLS with emphasis on early defibrillation for VF/pulseless VT 8

Monitoring for Return of Spontaneous Circulation (ROSC)

Signs of ROSC Include:

• Palpable pulse and measurable blood pressure 1, 2
• Abrupt sustained increase in PETCO2 to ≥40 mm Hg 1, 2
• Spontaneous arterial pressure waves on intra-arterial monitoring 1, 2

Once ROSC is Achieved:

• Immediately initiate post-cardiac arrest care 2, 8
• Maintain oxygen saturation >95% 2
• Treat hypotension with vasopressors if needed 2
• Consider therapeutic hypothermia for comatose patients 8
• Transfer to cardiac catheterization laboratory if acute coronary syndrome is suspected 8

Critical Pitfalls to Avoid

• Never delay CPR to establish vascular access or search for reversible causes—CPR comes first 2
• Do not administer IV bolus potassium during cardiac arrest for suspected hypokalemia—this causes harm 1
• Do not interrupt chest compressions for more than 10 seconds except for defibrillation 1, 2
• Do not give atropine during PEA or asystole—it has been removed from algorithms due to lack of benefit 2
• Do not provide excessive ventilation during CPR—this impairs venous return and cardiac output 2
• If PETCO2 remains <10 mm Hg despite CPR, improve compression quality immediately 1, 2