Use of ForceContinuum: Medical

AspectsGary M. Vilke, MD, FACEP, FAAEM

Professor of Clinical Medicine

Department of Emergency MedicineUniversity of California, San Diego Medical Center

DisclosuresNo corporate funding or financialinvestments in any of the companies whoseequipment will be discussed.

ObjectivesDiscuss medical related issues

Restraint position and asphyxiaOC sprayConductive Electrical Devices

Death in custodyDeaths have been associated with use offorce techniquesDeaths will continue to be associated withuse of force techniques

“POST HOC ERGO PROPTER HOC”"after this, therefore because of this."

Positional Restraint and Asphyxia

Positional Asphyxia - Pump Failure

LungFailure

gas exchange failurehypoxemia

PumpFailure

ventilatory failurehypercapnia

AirwayObstruction

hypoxemia & hypercapnea

RespiratoryFailure

Respiratory Failure

Original workTheory of Positional Asphyxia in custody restraint based primarily on

the work of Reay et al in 1988

Crossover study of 10 healthy individuals- exercised on ski machine to HR 120- measured recovery times for HR and O2 sat to baseline

in first the sitting then hogtie positions- prolonged recovery for HR and O2 sat in hogtie position

- mean O2 sat recovery time increased 20”- mean HR recovery time increased 24”

Reay et al: Effects of positional restraint on oxygen saturation and heart rate followingexercise. Am J Forensic Med Pathol 1988; 9(1):16-18.

Original workReay concluded that custody deaths are aresult of adverse physiologic andrespiratory effects of body position

Other caser reports and series1985 Wetli & Fishbain: 7 cases of custody death, 4 associated

with hogtie position

1992 Reay: 3 cases of positional asphyxia in individuals placedin prone restraint position in back of patrol cars

1993 O’Halloran and Lewman: 11 cases of sudden death insubjects in prone position (9 of them hogtied)

1998 Hick, et al: 5 cases of restraint-associated deaths resultingin profound acidosis suggesting acidosis exacerbated byhypoventilation as a result of body position

Case Report1995 Stratton et al: Twocases of unexpecteddeath in restrainedindividuals duringambulance transport

Conclude death causedby positional asphyxiafrom restraint for exciteddelirium

Case report similaritiesCases involved agitated, psychotic individuals in a

state of “excited delirium” usually fromrecreational drug use (cocaine,methamphetamines, ETOH)

Most cases involved traumatic struggle before andduring apprehension

No clear evidence of any other specific cause ofdeath on autopsy – diagnosis of positionalasphyxia

AutopsyPathologists base diagnosis of positionalasphyxia on temporal relationship ofrestraint to sudden death and lack of otherobvious cause of death on autopsy

Similar Sudden In-Custody Deaths reportedin prone, supine and sitting restraintpositions

Physiologic Studies - UCSD

Physiology Studies - UCSD1995 study funded by grant from the County of San Diego

Randomized cross-over controlled trial in 15 healthy subjects

Phase 1: PFTs (pulmonary function testing) in different positions:sitting, supine, prone, hogtie restraint

Phase 2: Serial ECG, oximetry, arterial blood gases, and PFTsduring 4’ stationary bicycle exercise followed by 15’ in thesitting and hogtie restraint

Chan TC, Vilke GM, Neuman T Clausen J: Restraint position and positionalasphyxia. Ann Emerg Med 1997;578-86.

Physiology Studies - UCSDIn healthy subjects, the restraint position resulted in

a restrictive pulmonary function pattern but did notresult in clinically relevant changes in oxygenationor ventilation.

We found no evidence to support the theory ofpositional asphyxia as a result of hogtie restraintbody position

Subsequent studiesRandomized cross-over controlled trial

of 18 healthy subjects

Phase 1: Exercised on bicycle up toHR 120 bpm, then measured HR andoximetry in the sitting and hogtiepositions. No difference in HRrecovery and no evidence of hypoxia

Phase 2: Simulated vigorous pursuitand struggle (ran 250m), followed bywrestling for 1’, then rest in sitting orrestrained position (lateral). Nophysiologic differences or hypoxianoted in recovery

Schmidt P, Snowden T: The effects of positional restrainton heart rate and oxygen saturation. J Emerg Med1999, 17(5): 777-82.

Physiologic studiesNo study, including the originalReay study, has shown that theprone restraint position results inhypoxia

Change in position“The hogtied prone position should be viewedas not producing significant physiologicrespiratory compromise, and it does notproduce any serious or life-threateningrespiratory effects”

Reay DT: Death in custody. Clinics Laboratory Medicine 1998;18(1):1-22.

Weight Force during Restraint?

Weight Force during Restraint?

Physiologic StudyWeight Force

Chan TC, Neuman T, Clausen J, Eisele J,Vilke GM: Weight force during pronerestraint and respiratory function. Am JForensic Med Pathol 2004;25:185-9.

Weight Force Study10 subjects placed in

sitting, PMRP, PMRP with25 lbs on back, and with50 lbs on back for 5minutes

PFTs, oxygen saturation,etCO2 measured

Chan TC, Neuman T, Clausen J, Eisele J, Vilke GM:Weight force during prone restraint and respiratoryfunction. Am J Forensic Med Pathol 2004;25:185-9.

OutcomesConclusion: Weight forceof 25 and 50 lbs on theback does not result inevidence of hypoxia orhypoventilatory respiratorycompromise in our healthysubjects.

Chan TC, Neuman T, Clausen J, Eisele J,Vilke GM: Weight force during prone restraintand respiratory function. Am J Forensic MedPathol 2004;25:185-9.

Weight ForceRecent UCSD/SDSUstudy looking atweights up to 225 lbson back in proneposition

PFT decreases to 85%(71.6-97.5% ofpredicted)No associated hypoxia

OC sprayInhalation can result in gagging, sob, cough,inability to vocalizeSymptoms transient (15-30’)Respiratory symptoms have led some to suggestrole in SDIC syndrome

AI claims over 90 deaths following OC spray use in 1990sGranfield: 30 deaths following OCO’Halloran: 21 SDIC, 10 of which involved OC.Pollanan: 21 deaths, 4 of which occurred after OC exposure

Similar deaths with OC sprayCases involved agitated,psychotic individuals in a stateof “excited delirium” usuallyfrom recreational drug use(cocaine, methamphetamines,ETOH)

Most cases involved traumaticstruggle before and duringapprehension

OC sprayFew studies on OC spray as opposed to capsaicin

California AG report on 23,000 uses: No fatalitiesWatson: 908 OC exposures, 10% required medical care,<1% resp sx, no fatalities2-year joint study of FBI & Army: No long-term healtheffects seen with OC spray exposure

Very few studies on respiratory effects of OCspray inhalation in humans

NIJ funded UCSD studyCrossover controlledtrial of 35 volunteers tofollowing:a. Placebo sprayfollowed by sittingpositionb. Placebo sprayfollowed by restraintpositionc. OC spray followedby sitting positiond. OC spray followedby restraint position

NIJ funded UCSD studyConclusions:

OC exposure did not resultin any evidence of hypoxia,hypoventilation, orrespiratory compromise

OC did not result in anyfurther change in pulmonaryfunction (FVC, FEV1) ineither sitting or restraintpositions as seen in theoriginal UCSD restraintstudy