The cardiopulmonary resuscitation, or CPR, delivered to Michael Jackson by his personal physician may not have been as effective as it could have been, heart experts told ABC News based on a transcript of the 9-1-1 call placed from Michael Jackson's Los Angeles mansion on the day of his death.
The transcript, which documents a call that Los Angeles emergency dispatchers received at 12:21 p.m. last Thursday, revealed that Jackson lay on a bed while receiving CPR from his personal physician Dr. Conrad Murray -- not on a floor or other hard surface as CPR experts suggest.
In was a point that the 9-1-1 dispatcher actually raised in his conversation with Jackson's security staff at the time of the emergency call.
"Do you have him on the floor? Where's he at right now?" the operator asked.
"He's on the bed sir," the caller responded. "He's on the bed. We need [paramedics]."
"Let's get him on the floor," the operator responded.
During his appearance on "Good Morning America" on Monday, Murray's attorney Ed Chernoff confirmed that Murray began administering CPR while Michael Jackson was lying on a bed.
"He did administer CPR on the bed," Chernoff said. "The bed is a very firm bed. He braced Michael Jackson's back with his hand under his back and compressed his chest with the other hand."
The American Heart Association recommends that cardiac arrest victims lie on a hard surface while receiving CPR -- usually either a backboard or the floor.
The reason for this, said Dr. Benjamin Abella of the University of Pennsylvania's Center for Resuscitation Science, is backed by research that suggests performing compressions while the patient is lying on a surface that is softer than the ground essentially robs the compressions of the power needed to keep blood flowing through the body until help arrives.
"When CPR is performed on a mattress, much of the 'depth' of compression is absorbed by the mattress, so that the chest does not move as much as it should," Abella said. "Chest compression depth is one of the most important characteristics of CPR, and several studies from our group and others have confirmed that better depth leads to better outcomes,"
Dr. Douglas Zipes, professor of cardiology at the Indiana University School of Medicine and past president of the American College of Cardiology, agreed. "[It's] very difficult to impossible to do CPR in bed; [there's] no leverage, no firm support, [and] no neck extension."
Jackson Too Frail for Normal CPR?
In certain cases, though, those performing CPR may be forced to resort to a less solid surface. Dr. Deepak Bhatt, director of the Integrated Interventional Cardiovascular Program at Brigham and Women's Hospital in Boston, said that depending on the circumstances, CPR on a softer surface can still be somewhat effective.
"Whether to move them if they are on an uneven or soft surface is not always clear," Bhatt said. "If moving the patient would delay instituting CPR -- if you were the only person in the area and could not easily lift them, for example -- it might make sense to start right away and scream out for help and then move the patient when a second responder arrives.
"It really is a matter of trying to use good judgment and weighing the risks of delaying potentially adequate CPR while aiming for perfect CPR," he said.
But reports of Jackson's frailty suggest that transporting him from the bed may not have been a major challenge. Rather, Murray braced Michael Jackson's back with his hand under his back and compressed his chest with the other hand. According to Miranda Sevcik, a spokewoman for Murray, the physician adopted this technique because he felt it was adequate considering Jackson's 110- to 125-pound frame.
Chernoff concurred. "He checked continuously to make sure there was blood flow and there was," he said. "It was effective, what he was doing. At some point he did bring him down off the bed and continue to administer CPR."
Cardiologists, however, disagreed that such a technique should be used with frail patients.
"I am not sure how he could have put his hand under him and at the same time delivered effective CPR," said Dr. Brian Olshansky, professor of cardiovascular medicine at the University of Iowa. "It usually requires both hands to compress the chest."
CPR May Have Been Too Little, Too Late
Still, better CPR may not have meant that Jackson would have been alive today, considering the period of time that had allegedly elapsed between Jackson's loss of consciousness and the arrival of paramedics.
Chernoff said that when Murray found Jackson unconscious in his bedroom, with only a weak pulse in his femoral artery, he immediately began CPR. But he also said it took Murray a while to find anyone in Jackson's rented mansion to help him call 9-1-1 after he failed to revive the superstar.
"He just happened to find him in his bed, and he wasn't breathing," the lawyer said. "Mr. Jackson was still warm and had a pulse."
Chernoff added that Murray's efforts continued for 25 to 30 minutes. If Jackson had gone into cardiac arrest at any point during his attempted resuscitation, as initial reports suggested, it is likely that the window to save his life would have been 10 minutes or less.
But one question which remains is whether there was an automatic external defibrillator available at Jackson's residence. An AED might have played a role in improving Jackson's chances for survival had it been available and implemented.
ABC News' Sarah Netter and Huma Khan contributed to this report.