I also participate in several codes and care of post code patients each week. Of those that make it to ICU, I view their CXRs to check for problems of concern for ventilation. Rarely do I see gross fractures of ribs. On some of these patients the sounds of cartilage popping during compressions were quite noticable. I also know from working in a monitored area, it takes a great deal of compression pressure to acheive effective hemodynamics during CPR. If you have the opportunity to take a chest trauma class later in your studies, you will learn about types of forces, angles and pressure that cause damage to the integrity of the chest and its contents. If you also get the opportunity to view an open chest cardiac surgery, you will see that the chest can be put through a lot even in the elderly and still come out okay.
Infants and pediatrics have the best chest recoil.
Good hand position and proper postion of your body over the patient will give you and the patient the best advantage. I have seen more serious displaced rib fractures in hospital CPR because the performers were not able to get into proper body position initially. This can be due to the different types of air beds, rails, trapezes, and width of the bed. Many of the special needs beds are difficult to get on with the patient to perform properly angled CPR. Bariatric beds can be particularly difficult. The patient may also be attached to many different pieces of equipment to disallow prompt movement into good position. Sometimes you almost hope for the code to be on the floor or have an ambulance stretcher nearby even in the hospital setting.
This is an article I saw recently in Cardiovascular Engineering. The actual article is not available yet online with out a subscription but here is a reference to that article and its contents:
http://www.sciencedaily.com/releases/2007/05/070531113247.htm
CPR: More Rib Fractures, But Better Survival Rates
Science Daily — New findings show that the majority of people untrained in how to perform cardiopulmonary resuscitation, and even many trained emergency personnel, do not push with enough force to properly administer CPR.
The research tested 104 adults untrained in CPR and 83 firefighters, trained in the procedure. The findings, to be published in the June issue of the journal Cardiovascular Engineering¹, showed that most of the untrained people simply do not apply enough force, said Leslie Geddes of Purdue University, one of the authors of the study.
The success rate for CPR ranges from 5 percent to 10 percent, depending on how quickly it is administered after a person's heart stops. "This is important because every minute lost in applying CPR results in a 10 percent decrease in successful resuscitation," Geddes said. "Time is the enemy. After 10 minutes, very few are resuscitated. The American Heart Association recommends pushing with enough force to compress the chest 1.5 to 2 inches, which requires 100 to 125 pounds of force.”
The research represents the first time such measurements have been recorded to quantify just how hard people push in a simulated CPR test. The findings showed that 60 percent of the CPR-trained rescue personnel pushed with more than 125 pounds, whereas more than 60 percent of those not trained in CPR failed to push with more than 125 pounds of force.
http://www.sciencedaily.com/releases/2007/05/070531113247.htm
Pushing with more than 125 pounds increases the potential for rib fractures. Nevertheless, the chances of survival increase enormously. New guidelines from the American Hearth Association recommend that rescuers performing CPR should "push harder and faster," Geddes said. "As a result of this recommendation, it's likely that the resuscitation rate will increase, but it's equally likely that the fracture rate will increase."
