Recommended Chest Compression Depth for Adult CPR
For adult victims requiring cardiopulmonary resuscitation (CPR), the recommended chest compression depth is approximately 5 cm (2 inches), while avoiding compression depths greater than 6 cm (2.4 inches). 1
Optimal Compression Depth Guidelines
The International Liaison Committee on Cardiopulmonary Resuscitation (ILCOR) provides clear guidance on chest compression depth:
- Target depth: Approximately 5 cm (2 inches) 1, 2
- Upper limit: Avoid exceeding 6 cm (2.4 inches) 1, 2
- Strength of recommendation: Strong recommendation for the 5 cm target depth (despite low-quality evidence) 1
This recommendation has remained consistent in recent guidelines, with the 2021 international consensus continuing to support a chest compression depth of ≈5 cm while avoiding excessive depths >6 cm 1.
Physiological Basis and Evidence
Research shows a "sweet spot" for compression depth between 4.03 and 5.53 cm (1.59-2.2 inches), with peak effectiveness at approximately 4.56 cm (1.8 inches) 1. This range optimizes:
- Coronary perfusion pressure
- Cardiac output
- Likelihood of successful defibrillation and ROSC
Studies demonstrate that:
- Compressions that are too shallow (<5 cm) are associated with decreased ROSC and reduced survival 2, 3
- Compressions that are too deep (>6 cm) increase the risk of injuries including rib fractures, sternal fractures, and internal organ damage 2
Implementation Challenges
Several factors affect the ability to maintain proper compression depth:
- Rescuer fatigue: Compression depth begins to decrease after 90-120 seconds of CPR 2
- Compression rate: Higher rates (>120/min) can lead to decreased depth 4
- Surface firmness: CPR should be performed on a firm surface when possible 1
- Perception challenges: Both professional and lay rescuers have difficulty estimating the correct compression depth 5
Practical Application
To achieve optimal compression depth:
- Position hands at the center of the chest (lower half of sternum) 1
- Keep arms straight with shoulders directly over hands
- Use body weight rather than arm strength
- Allow complete chest recoil between compressions 1, 2
- Minimize interruptions to maintain adequate blood flow
- Rotate compressors every 2 minutes to prevent fatigue-related depth deterioration 2
Common Pitfalls to Avoid
- Insufficient depth: Over 50% of compressions are too shallow by 2005 standards (<38 mm) and over 90% by current standards (<50 mm) 3
- Leaning on the chest: Prevents full chest wall recoil and reduces venous return 1
- Excessive compression rate: Can lead to decreased depth 4
- Interruptions: Minimize pauses to maintain perfusion
Audiovisual feedback devices as part of a comprehensive quality improvement program can help rescuers maintain proper compression depth during CPR 1, 2.