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Autopsy Errors withElectronic Control Devices:A Cardiovascular PerspectiveMark W Kroll, PhD, FACC, FHRSFaculty of UCLA Creativity and Innovation ProgramAdjunct Full Professor, Biomedical Engineering, Cal Poly Univ.Adjunct Full Professor Biomedical Engineering, U of MinnesotaTaser Intl Scientific and Medical Advisory Board.
Co-Authors Jeffrey D. Ho, MD, Dept. of Emergency Medicine, HennepinCounty Medical Center, Mpls, MN.Dorin Panescu, PhD, Sunnyvale, CA.Igor R. Efimov, PhD, Washington Univ, St. Louis, MO.Richard M. Luceri, MD, Holy Cross Hospital, Ft. Lauderdale, FL.Patrick J. Tchou, MD, Cleveland Clinic, Cleveland, OH.Hugh Calkins, MD, Johns Hopkins Hospital, Baltimore, MDAAFS 2007
Electronic Control Devices areReplacing the ClubAAFS 2007
In Custody Deaths Correlate with HandcuffsAAFS 2007
X26 Waveform Typical peak current: 3.3 amperesTypical peak loaded voltage: 1200 VPulse average voltage: 400 VMain phase duration: 100 µsDelivered charge: 100 µC– At 70 µs it delivers about 80 µC Average currentAAFS 2007
TASER ECDs Off the Chart(Well Below Safe VF Limits)AAFS 2007
So, How Can It Capture SkeletalMuscles but Not Affect the Heart? Anatomy– Skeletal muscles are on the outside of the body.– Heart is on the inside of the body.– Electrical current tends to favor the grain of themuscle by 10:1 vs. going against the grain. So current tends to stay on the outside.Optimal stimulation pulse widths are different:– A-α motor neuron chronaxie: 50–150 µs– Heart for transcutaneous stimulation: 4 ms 4000 µsAAFS 2007
Cleveland Clinic Study America’s top heart hospital 6 years in a row byU.S. News & World Report.Cocaine increased safety margin by 50-100%Lakkireddy DR, Wallick D, Ryschon K,Chung MK, Butany J, Martin D, SalibaW, Kowalewski W, Natale A, Tchou PJ.Effects of Cocaine Intoxication on theThreshold for Stun Gun Induction ofVentricular Fibrillation. J Am CollCardiol 2006;48:805–11.AAFS 2007
Breathing UnimpairedAcad Emerg Med. 2007 Feb 5AAFS 2007
Medical ElectrocutionOccurs 500 Times Per Day1.2.3.4.5.6.VF is either induced or not induced within1-4 seconds.Asystole or PEA are never induced.The cardiac pulse disappears immediately.The patient loses consciousness within 5-15seconds.A defibrillation shock—either internal orexternal—restores a sinus rhythm 99.9% ofthe time.There is no increased risk of a later VF sinceelectrical current does not linger in the bodyas a poison or drug might.AAFS 2007
2005 Was A Bad Year for Science43210200120022003200420052006AAFS 2007
The Index Case for 2005 Ronald Hasse age 54Naked, on 26th floorTalking to aliens on his cell phoneCPD and EMS show upTASER ECD is used to take him intocustodyDiesAAFS 2007
Hasse HeadlinesChicago Sun-Times, Jul 29, 2005 Taser Killed Man, Pathologist Finds. In the first ruling of its kind in the nation, the CookCounty medical examiner's office has determinedthe Feb. 10 death of Ronald Hasse was caused by aTaser stun gun Hasse received a five-second electrical burst fromthe Taser, followed by a 57-second charge,according to Dr. Scott Denton, a deputy medicalexaminer.AAFS 2007
Sun Times story ctd. The primary cause of Hasse's death waselectrocution from the use of the Taser, Denton said.A contributing cause was methamphetamineintoxication, he said. .55 µg/ml of methamphetamine -- 10% over lethallevel But the illegal drug probably would not have killedHasse without his getting "pushed over the edge" bythe Taser's jolts, Denton said.DME stressed that what was different was the long57 second application which is what killed Hasse.AAFS 2007
ECD Download Shows that theLonger Application was the First — Not the Latter!AAFS 2007
What Really Happened? Hasse tried to kick and bite officers and threatenedto infect police with HIV.A 57 second TASER hit dropped Hasse.Immediately after he resisted again.This time they need a 5 second therapy until theyare able to get handcuffs on.Hasse then climbed into the stair-chair.Paramedics verify normal pulse and respiration.Hasse wheeled to elevator.Alert with eyes open going into elevator.AAFS 2007
ChicagoParamedic
Taken down 26 floors.Collapses on ground floor 8 minutes afterECD application.Defibrillation unsuccessful.Death clearly not caused by ECD:––––Continued to struggle after first application.Normal pulse after both applications.Normal respiration after both applications.Collapse 8 minutes not 8 seconds after ECDusage.– Failure of immediate defibrillation.AAFS 2007
Autopsy Mentions of TASERECDsAAFS 2007
Scored Errors Failure to appreciate that withelectrocution:1. pulse disappears immediately,2. there is loss of physical strength forcontinued resistance3. collapse occurs within 5-15 seconds4. VF rhythm is shown on a cardiac monitor5. immediate defibrillation is usuallysuccessfulAAFS 2007
Other Scored Errors6.7.8.9.10.11.12.Blaming the ECD for cardiac physical changesInclusion of a publicity sensitive safe comment (e.g. “we wereunable to eliminate the role” of the ECD)Assuming prolonged ECD applications are more dangerousthan other restraint techniquesClaiming that ECDs impair breathingPresumption of a lethal synergy between stimulant drugs andthe ECDUse of the ECD in the “drive stun” mode only since thisinvolves current passing between 2 very close electrodesUnscientific emotional explanations such as “last straw” or“pushed over the edge.”AAFS 2007
The ScorecardProbable Error in Citing the ECDTime to collapse 1 minuteContinued resistance after ECD applicationRhythm other than VFPublicity sensitive commentsAssumed drug-ECD electrocution synergyDischarge duration or parityFailure of immediate defibrillationDrive stun mode“Last straw” or “over the edge”Cardiac damage ascribed to ECDAssumed ventilation impairmentN21161298776643AAFS 2007
Error Rate of 3.1 1.2 per AutopsyData as of Abstract Submission654321035,700 35,900 36,100 36,300 36,500 36,700 36,900 37,100 37,300AAFS 2007
TASER-related Errors Dropping Fast!AAFS 2007
Error Analysis Conclusions 90% of autopsies have no errors re the roleof electronic control devices.Cardiogenic etiology errors are droppingrapidly.It is impressive that medical examiners haverapidly familiarized themselves with:––––time and causation elements of electrocution,ventricular fibrillation,ECD technology, andexcited deliriumAAFS 2007
AAFS 2007 Medical Electrocution Occurs 500 Times Per Day 1. VF is either induced or not induced within 1-4 seconds. 2. Asystole or PEA are never induced. 3. The cardiac pulse disappears immediately. 4. The patient loses consciousness within 5-15 seconds. 5. A defibrillation shock—either
