This morning’s session began with Dr Shafer in the witness box, resuming his testimony on the effects of drugs in Michael’s system. He showed diagrams of the digestive tract in a human body, with veins from that tract moving blood straight to the liver. He said that once the blood reaches the liver, that reacts and removes up to 99% of the drug, thus proving that if Michael had drunk the Propofol, the liver would remove it before he could have been sedated, having no effect at all on his body. This means that there was zero possibility that he died as a result of ingesting Propofol. It was discussed that the more likely scenario was that Murray placed Michael on an IV Propofol drip on the morning of his death then left later to make a series of phone calls as Michael slept, Shafer said. Michael probably stopped breathing before Murray returned and his lungs emptied while the Propofol kept flowing into his body, Dr Shafer said. “This fits all of the data in this case and I am not aware of a single piece of data that is inconsistent with this explanation,” he added.
Dr Shafer’s colleague DrWhite, who will give evidence for the Defense, had suggested to them that death through ingestion of Propofol was a possibility. Dr Shafer produced various papers on the subject, with Propofol being tested orally on mice, piglets, rats, dogs and monkeys. In none of those experiments did Propofol induce anaesthesia and it was therefore realised that oral ingestion was not considered appropriate.
Dr Shafer went on to speak of his experiment on humans taking Propofol orally, when a study in Chile was undertaken with Dr Shafer, Dr Sepulveda and Dr Contreras.
Six subjects were used, three taking 200mls of Propofol orally and three taking 400mls also orally. Their blood pressure was monitored and the level of sedation was measured. At no time were the subjects sedated at all! Oxygen levels never dropped and blood pressure never dropped. The results of the experiment were published. Ingestion of Propofol had no effect on humans!
After Dr White’s paper was published the Drug Enforcement Agency was concerned that the publicity about the drug would affect patients’ understanding of Propofol and the DEA would have liked to restrict its use. It could have resulted in the misconception that it placed patients at risk and was dangerous. The specialists had to argue the actual benefits of the drug and the DEA withdrew its objections.
All research confirmed also, that it could not have caused Michael’s death.
Mr Walgren then turned his attention to the drug Lorazepam which Murray had also given to Michael before he died. Dr Shafer referred to a study done at Stamford University specifically for this case. Lorazepam and Medazolam had both been studied to compare dosages given by computer in the Intensive Care Unit. The computer had recorded precise dosages of both drugs and blood levels from arteries had been compared. The amount of data used was huge and was studied intensely Dr Geller, Head of the ICU at Stamford conducted the study. Dr Shafer analysed the data and also the toxicology data.
In Michael’s case, the amount of Lorazepam found at the autopsy in the femoral bloods was 0.169. Murray had given Michael two, 2 miligram doses during the night. Dr Shafer did multiple tests on that dosage and produced models which he explained to the jury in great detail, explaining step by step what had happened to the levels of the drug in Michael’s blood. The conclusion reached showed that Michael had obviously received more than the 4mls of Lorazepam Murray claimed to have given.
Pacific Toxicology had also conducted experiments on the same subject and Dr Shafer explained their testing methods and how Lorazepam would reach the stomach if given intravenously into the arm. The process was explained in depth, ending with the Lorazepam reaching the stomach from the bile duct and gall bladder. The Lorazepam has also become a Glucoronide and 25% flows into the intestinal tract and the amount in the stomach showed at literally one forty-third of a tablet, as was given in evidence by an earlier expert.
Mr Walgren asked abourt Pharmokinetics, or drugs in motion in the body and PharmoDynamics, or how powerful the drug is in the body. The doctor spoke at length about the basic concepts of both of these topics, using slides and models to illustrate basic concepts for example; like how the drug affects the body in any given concentration. His studies of Michael’s case were conducted at Stamford University. He programmed the data into infusion pumps, and watched and recorded the results. He specifically used Michael’s gender, his weight and age and studied the effects of the drug on his brain, as Propofol only acts on the brain, not in the blood. An experiment using a colleagues actual brainwaves, was performed and using the delay figures could work out the concentration of the drug in his brain. Next he used Dr White’s paper on apnea – a time when the patient stops breathing, to calculate at what point a patient stops breathing after Propofol is administered. He explained to the jury the concentrations in the brain necessary to bring about apnea and the length of time in which that happens. A further paper was consulted to assess how long after the patient stops breathing does the heart stop. The technical details were extremely complex and delivered quite rapidly, but with illustrations to clarify them for the jury. The level of Propofol in Michael’s femoral blood was 2.6% and was very close to the apnea level. Dr Shafer spoke at length on the blood levels in the brain and outside the brain and demonstrated his absolute knowledge of his subject. When asked if a 25ml dose of Propofol together with the other drugs Michael had been given, would decrease the drive to breath. The doctor replied “Absolutely!” There were no safety procedures in place and the standards of care were not in place, so even the smallest amount of the sedative could form a risk.
The doctor described the effects of a 50ml dose of Propofol together with 50mls of Lidocaine. Between one minute and three to four minutes Michael would have stopped breathing. The heart could have carried on beating for another ten – fifteen minutes. The doctor said that therefore a 50mls dose could be discounted. If an entire syringe of 100mls of Propofol only was given, the Propofol levels in the brain would quickly reduce and apnea would occur within one minute and the heart would stop in ten minutes. However, the blood level from the femoral artery was high, so that rules out a dose of 100mls of Propofol. Mr Walgren asked if multiple injections have been given, the doctor answered; ‘Yes.” Because Michael’s veins were in a poor condition an IV had to be placed just below his left knee making direct self-injection highly unlikely. Repeated injections were also unlikely in this case, as Michael would have to be awake to inject himself and he can’t re-inject if he is asleep. All the time Propofol was accumulating in his body, it was NOT washing out so Dr Shafer’s opinion was that self injection did not happen. The doctor then gave two further examples to prove that self injection could not have happened in this case.
After the lunch break Dr Shafer demonstrated the IV set up as it was in Michael’s room the night he died, introducing each piece of equipment and explaining its use. It was also noted by some observers that, using a magnifying glass, the doctor had inspected the actual vial which was said to have been used with a spike, not a syringe as claimed. This vial was a piece of evidence in the case.
At one point the Defense requested a sidebar and Murray, whose composure has always been very calm, grew quite animated and alarmed. No explanation was apparent at the time.
The IV set up continued as the doctor connected each piece exactly as it was in Michael’s home. There was evidence that Murray had ordered such a set which was made by the Braun Company. “People don’t just wake up from anaesthesia hell bent to pick up a syringe and pump it into the IV,” Shafer said, reminding the jury that the procedure was complicated. “It’s a crazy scenario.”
He also said again that it was unlikely that Michael injected himself with a needle because his veins were too deteriorated and the procedure would have been extremely painful.
Tomorrow, the Defense is expected to begin their cross examination of Dr Shafer.