What Happens When You Ventilate Too Much? Excessive ventilation during cardiopulmonary resuscitation can be harmful, especially in cases of cardiac arrest, shock, or heart attack. While proper ventilation is essential to deliver oxygen to the lungs and remove carbon dioxide, too much ventilation disrupts the delicate balance required for effective resuscitation.
When ventilations are too frequent or delivered with excessive volume, they increase intrathoracic pressure. This impairs venous return to the heart, reduces cardiac output, and ultimately lowers survival rates. Hyperventilation can also cause gastric inflation, leading to regurgitation and aspiration, which further complicates resuscitation efforts.
In this blog, we’ll explain what excessive ventilation is, why it’s harmful, what complications it can cause, and how to avoid it during CPR.
Understanding Excessive Ventilation in CPR
Ventilation is an important part of CPR. It helps to deliver oxygen to the lungs and removes carbon dioxide from the body. When a rescuer gives too many breaths, breathes too quickly, or uses too much force, it leads to excessive ventilation. This can create high pressure inside the chest which makes it harder for the heart to fill with blood between compressions. As a result, less blood is pumped to vital organs like the brain and heart.
Excessive ventilation also raises the risk of gastric inflation, which can lead to vomiting and airway obstruction. These complications can make the rescue process more difficult and reduce the chances of a successful outcome.
What are the Consequences of Excessive Ventilation?
Excessive ventilation during CPR can cause several harmful effects that reduce the chances of a successful resuscitation. It can reduce the flow of blood to the heart and brain, which lowers the chance of saving the person. Too much air can also go into the stomach instead of the lungs, causing the person to vomit or choke. In some cases, it can even hurt the lungs. That’s why it’s important to give breaths slowly and gently, just enough to make the chest rise.
Here are the major consequences of excessive ventilation:
1. Decreased Blood Return to the Heart
One of the major consequences of excessive ventilation during CPR is reduced blood return to the heart. Over-ventilation increases intrathoracic pressure, which compresses the large veins and limits venous return. As a result, less blood fills the heart between compressions, which leads to decreased cardiac output.
When the heart doesn’t get enough blood, it can’t pump enough oxygen to the brain and other important organs like the liver and kidneys. Without enough oxygen, these organs can start to fail.
2. Gastric Inflation and Aspiration Risk
Excessive ventilation during CPR can cause gastric inflation and aspiration risks, which means air enters the stomach instead of the lungs. This usually happens when breaths are delivered too quickly, too forcefully, or without proper airway positioning. As a result, the stomach fills with air, and the risk of vomiting increases.
If the victim vomits, there is a high chance of aspiration, where stomach contents are inhaled into the lungs. Aspiration can block the airway, lead to pneumonia, or cause serious breathing complications. To reduce this risk, rescuers must provide slow, gentle breaths and ensure proper head positioning during ventilation.
3. Delayed Return of Spontaneous Circulation (ROSC)
Return of Spontaneous Circulation (ROSC) is the moment when the heart starts beating effectively on its own after cardiac arrest. Excessive ventilation can delay or even prevent this critical milestone. When too much air is delivered, it increases pressure in the chest and reduces blood flow back to the heart. This leads to poor circulation, making it harder for the heart to restart.
Over-ventilation reduces the effectiveness of chest compressions and limits oxygen delivery to the heart muscle. These factors combined can delay ROSC and lower the chances of survival after resuscitation.
4. Interrupted Chest Compressions
Chest compressions are the most critical component of CPR, as they help maintain blood flow to essential organs like the brain and heart. Excessive ventilation often causes rescuers to pause compressions too frequently or for too long. These interruptions break the heart rhythm needed to build and sustain blood pressure, which makes CPR less effective and decreases the victim’s chance of survival.
It’s important to avoid interruptions during CPR and follow the recommended compression-to-ventilation ratio or advanced airway steps to improve the chances of survival. Always make sure to give high-quality chest compressions and breaths to help the person as much as possible.
Recognizing the Signs of Excessive Ventilation in CPR
Recognizing the signs of excessive ventilation during CPR is critical to preventing further harm and improving the victim’s chances of survival. Over-ventilation can quickly lead to dangerous complications if not identified and corrected in time.
Healthcare professionals such as doctors, nurses, EMTs, and paramedics play a vital role in managing ventilation during resuscitation. While performing CPR, you must stay focused, follow the CPR guidelines, and monitor the victim’s responsiveness.
Some common signs of excessive ventilation include:
- The chest inflates more than necessary
- Breaths are given too quickly or with strong force using a Bag-Valve Mask (BVM)
- Decreased oxygen levels despite ventilation efforts
- Gurgling sounds or vomiting (signs of gastric inflation)
- No improvement in oxygen saturation despite continued ventilation
How to Prevent Excessive Ventilation During CPR?
Whether you’re a healthcare provider or a trained lay rescuer, following proper ventilation techniques helps protect the heart, lungs, and brain during resuscitation. While taking any action on the victim, you need to stay calm and confident to provide effective ventilation.
It is essential to perform high-quality chest compressions and follow advanced airway guidelines to increase survival rates. This will improve the person’s chance of survival and help avoid problems caused by too much ventilation.
Here are a few steps that you can consider to prevent over-ventilation during CPR:
- Follow the AHA-recommended ventilation rate by giving 1 breath every 6 seconds or using a 30:2 ratio without an advanced airway.
- Use proper tidal volume by delivering only enough air to produce a visible chest rise.
- Monitor the victim’s chest closely and stop ventilation as soon as chest rise is observed.
- Use a metronome or CPR feedback device to maintain accurate ventilation timing and rhythm.
- Stay calm under pressure and avoid breathing too quickly due to stress or panic.
Conclusion
Excessive ventilation during CPR can reduce oxygen delivery, increase intrathoracic pressure, and cause dangerous complications like aspiration and gastric inflation. These effects can prevent the return of a normal heartbeat and lower survival chances. Whether you’re a healthcare professional or a trained bystander, understanding these risks and applying proper ventilation techniques is crucial to improving patient survival.
If you want to gain life-saving skills to confidently respond during a cardiac arrest emergency, trust Heart Start CPR, an AHA-authorized training center. We offer a wide range of courses, including ACLS, PALS, BLS, CPR, and First Aid. Our certified instructors focus on delivering high-quality CPR while teaching you how to avoid the dangers of excessive ventilation. Enroll in an ACLS class today to master advanced skills and learn how to maintain the correct ventilation-to-compression ratio during resuscitation.
