Dr. Bradford Wankhede Langenfeld was the first witness called to the stand Monday, testifying that he directed the care of Floyd at Hennepin County Medical Center and spent about 30 minutes trying resuscitate him before pronouncing him dead.
Langenfeld, first licensed in May 2020, was a senior resident at the time who worked under attending physicians. Questioned by prosecutor Jerry Blackwell, Langenfeld said he "provided the majority of direct patient care" to Floyd under the supervision of another doctor, Dr. Ashley Strobel.
Langenfeld testified that the paramedics who brought Floyd to the hospital did not give him any information that Floyd might have overdosed on drugs or suffered a heart attack.
Langenfeld said Floyd had some electrical activity around the heart, but no pulse. His heart monitor eventually flat-lined, Langenfeld said, and Floyd's heart never resumed beating on its own "to a degree necessary to sustain life."
"Any time a patient spends in cardiac arrest without CPR markedly decreases the chances of a good outcome," he said. Langenfeld said there's approximately a 10-15% decrease in survival rate per every minute that passes without CPR.
Asked by Blackwell what was determined to be the cause of Floyd's cardiac arrest, Langenfeld said: "At the time, based on the history available to me, I felt that hypoxia was one of the most likely possibilities." Hypoxia is a lack of oxygen, which Lagenfeld said he believed led to Floyd's death from asphyxia.
During cross-examination by lead defense attorney Eric Nelson, Langenfeld acknowledged that a combination of fentanyl and methamphetamine could cause hypoxia. A toxicology screen of Floyd after his death found fentanyl and methamphetamine in his system.
Responding to a question from Nelson, Langenfeld testified that a "primary reason" fentanyl is so dangerous is that it depresses the respiratory system. Answering Nelson, Langenfeld agreed that a person could die from using fentanyl even if they had become accustomed to taking the drug.
The testimony was an important moment in the trial. The prosecution is trying to show that Floyd died because of how Chauvin restrained him with a knee to the neck area while the defense is trying to show that other causes – drug use and poor heart health – led to Floyd’s death.
Derek Chauvin trial live: Doctor believed lack of oxygen 'likely' caused Floyd's death; Police chief Medaria Arradondo testifies