Dr. Martin Tobin, a pulmonologist and physician with experience in critical care medicine, testified in court on Thursday (April 8) that George Floyd died from a lack of oxygen while Derek Chauvin was kneeling on his neck. After reviewing the medical records in the case, Dr. Tobin took the stand for the ninth day in Chauvin’s murder trial.
“Mr. Floyd died from a low level of oxygen,” he told the court. “And this caused damage to his brain that we see and it also caused a PEA arrhythmia that caused his heart to stop.”
PEA, he explained, means pulseless electrical activity, “which is a particular form of abnormal beat of heart — an arrhythmia.”
“The cause of the low level of oxygen was shallow breathing. Small breaths. Small tidal volumes. Shallow breaths that weren’t able to carry the air through his lungs down to the essential areas of the lungs that get oxygen into the blood and get rid of the carbon dioxide,” Tobin continued.
The doctor also identified what cause Floyd’s lack of oxygen, listing the prone position; Chauvin’s knee on his back and neck; and the handcuffs, which were pressing into Floyd’s back.
Tobin also said that “a healthy person” without Floyd’s pre-existing medical conditions would also have died in the position.
“A healthy person subjected to what Mr. Floyd was subjected to would have died as a result of what he was subjected to,” he said.
Dr. Tobin further revealed that Chauvin kept kneeling on Floyd for over three minutes after he was completely depleted of oxygen.
“There is not an ounce of oxygen left in his body. And again... you can figure this out with very precise science. Looking at once somebody stops breathing, what will be the rate of decline in oxygen, how long it will take to reach zero,” Tobin said. “... The knee remained on the neck for another three minutes and two seconds after we reached the point where there was not one ounce of oxygen left in the body.”
On Thursday, jurors also learned that Floyd suffered a seizure while Chauvin was holding him down, indicated by his leg movements.
“We see and we can tell from the movement of his leg that the level of oxygen in his brain has caused what we call a myoclonic seizure activity,” he said. “Those are medical terms, but basically it means he has kicked out his leg in an extension form... and that is something we see as clinicians in patients when they suffer brain injury as a result of a low level of oxygen.”
Court recessed for a lunch break after Tobin’s testimony and will resume at 1:30 pm local time. Chauvin is charged with second- and third-degree murder and second-degree manslaughter in Floyd’s death.