When performing Cardiopulmonary Resuscitation (CPR), the application of force during chest compressions can sometimes lead to injuries, including fractures of the sternum, or breastbone. While rib fractures can occur during CPR, the priority is to save lives. The sternum, a long, flat bone located in the center of the chest, is vulnerable to fracture due to the pressure exerted during compressions. This article explores the causes behind sternum fractures during CPR, their prevalence, the importance of chest compressions, and why CPR remains a critical life-saving technique despite these risks.
Understanding the Mechanics of CPR
CPR is an emergency procedure that combines chest compressions with artificial ventilation to maintain circulatory flow and oxygenation during cardiac arrest. The chest compressions are performed on the chest to manually pump the heart, thereby ensuring blood continues to circulate to vital organs, especially the brain. However, the force required to achieve effective compressions can sometimes result in injuries, including fractures of the ribs or sternum.
1. Why Force is Necessary in CPR
Effective chest compressions require significant force—approximately 2 to 2.5 inches of compression depth—to properly circulate blood. This force is crucial for creating enough pressure to maintain blood flow, but it can sometimes break ribs, increasing the risk of injuring the structures within the chest, particularly the sternum and ribs.
2. The Role of the Sternum in Chest Compressions
The sternum serves as the focal point for chest compressions, as it lies directly over the heart and major blood vessels. Compressions applied to this area help squeeze the heart between the sternum and the spine, facilitating blood flow. However, because the sternum is a relatively rigid structure, it is prone to cracking or breaking under intense pressure, potentially leading to a fractured sternum and serious complications such as cardiac rupture.
Causes of Sternal Fractures During CPR
Several factors contribute to the occurrence of sternal fractures during CPR. Understanding these factors can help highlight the balance between effective CPR and the potential for injury. CPR-related injuries can include rib and sternal fractures, as well as soft tissue injuries, which vary in severity and incidence rates depending on the scenario.
1. The Necessary Force for Effective CPR
The primary cause of sternal fractures during CPR is the significant force required to perform effective chest compressions. The depth and pressure needed to manually pump the heart often exceed the bone’s tolerance, leading to broken ribs, especially in individuals with compromised bone integrity.
2. Rib Resilience and Its Impact
The ribs, which are connected to the sternum, absorb some of the force during compressions. However, ribs are designed to be more flexible and can bend under pressure, whereas the sternum is less flexible and more prone to cracking. The combination of rib resilience and the rigid nature of the chest wall makes the sternum more susceptible to fractures.
3. Age and Bone Fragility
Age is a significant factor in the likelihood of sustaining a sternal fracture during CPR. Older adults are more likely to experience bone density loss due to conditions like osteoporosis, making their bones more fragile. This fragility increases the risk of fractures and other severe injuries when compressions are applied with the necessary force.
4. Quality of CPR
High-quality CPR is characterized by compressions that are both deep and fast, typically at a rate of 100-120 compressions per minute. While this is necessary to maximize the chances of survival, the increased force and rapid pace can elevate the risk of skeletal chest injuries, including rib and sternal fractures, especially if the rescuer is particularly strong or if the victim has underlying health issues.
Prevalence of Sternal Fractures During CPR
Sternal fractures during CPR are not exceedingly common, but they do occur with some frequency, particularly in specific populations. Understanding the prevalence and factors that influence the likelihood of these fractures is important for both healthcare providers and bystanders trained in CPR. Additionally, chest injuries, including rib and sternal fractures, can occur during CPR, influenced by factors such as age, gender, and the skill level of the CPR provider.
1. Statistical Incidence of Sternal Fractures
The incidence of sternal fractures during CPR varies across studies, but it is generally considered a rare complication compared to rib fractures. Some studies estimate that sternal fractures occur in approximately 1-8% of CPR cases, with higher rates reported in elderly patients or those with pre-existing bone conditions.
2. Contributing Factors to Fractures
Factors such as the depth of compressions, the physical condition of the person receiving CPR, and the skill and strength of the rescuer all contribute to the likelihood of a fracture. For example, more forceful compressions, while necessary, can increase the risk of injury, particularly in older adults or those with osteoporosis. Additionally, severe complications such as cardiac rupture can arise from CPR, especially due to direct trauma from a fractured sternum, leading to tears in heart structures.
3. Balancing Risk and Benefit
Despite the risk of sternal fractures, the benefits of performing CPR far outweigh the potential for injury. Cardiac arrest is a life-threatening condition, and without CPR, the chances of survival are slim. The possibility of a fracture should not deter anyone from performing CPR when necessary, as the primary goal is to save a life.
Importance of Chest Compressions in CPR
Chest compressions are the most critical component of CPR, particularly in the first few minutes of cardiac arrest. They ensure that blood continues to circulate to the brain and other vital organs, which is crucial for preventing irreversible damage. However, complications such as liver injury can arise during chest compressions, highlighting the importance of proper technique to minimize such risks.
1. Maintaining Circulatory Flow
Chest compressions mimic the natural pumping action of the heart, maintaining circulatory flow during cardiac arrest. This flow is essential for delivering oxygen to the brain and other vital organs, preventing brain damage and other complications that can arise from prolonged oxygen deprivation.
2. Oxygen Delivery to Vital Organs
During cardiac arrest, the heart is no longer able to pump blood effectively. Chest compressions help maintain oxygen delivery to the brain and heart, which is critical for preserving organ function and increasing the chances of a successful resuscitation.
3. The Critical Role of Depth and Rate
The depth and rate of chest compressions are key to their effectiveness. Compressing the chest by at least 2 inches at a rate of 100-120 compressions per minute has been shown to be most effective in maintaining blood flow. However, these parameters also increase the potential for fractures, particularly in individuals with fragile bones.
Managing the Risks Associated with CPR
Understanding the risks associated with CPR, including the potential for sternal fractures, is important for anyone trained in this life-saving technique. Proper training and awareness can help mitigate these risks while ensuring that CPR is performed effectively.
1. CPR Training and Awareness
CPR training programs emphasize the importance of correct hand placement, compression depth, and rate to maximize effectiveness while minimizing the risk of injury. Being aware of the potential for fractures can help rescuers prepare for this possibility and ensure that they continue to perform CPR with confidence.
2. Handling Fractures During CPR
If a fracture occurs during CPR, it is important to continue with compressions. The priority is to maintain blood flow and oxygen delivery, as the potential for saving a life far outweighs the concern of a broken bone. Once professional medical help arrives, they can assess and manage any injuries sustained during the resuscitation process.
3. Reassurance for Rescuers
Rescuers should be reassured that the occurrence of a sternal fracture does not indicate a failure in their CPR technique. Instead, it reflects the force necessary to perform effective chest compressions. The emphasis should always be on saving the life of the person in cardiac arrest.
Conclusion
While the risk of fracturing the sternum during CPR exists, it is a rare but acceptable risk when weighed against the life-saving potential of the procedure. Cardiac arrest is a critical emergency where every second counts, and the primary focus should always be on delivering high-quality CPR to preserve life. Proper training, awareness, and confidence in performing CPR are essential for anyone who may find themselves in a situation where these skills are needed. Despite the possibility of causing an injury, the benefits of CPR far outweigh the risks, making it a crucial intervention in the event of cardiac arrest.
