Hypothermia, exhaustion

and drowning

Capita Selecta AMC Non DCI related disorders

18-3-2017

Mattijn Buwalda Anaesthesiologist-intensivist & DMP

www.mattijnb.nl Runtime: 40 min

Slides: 36

• drowning is the process of experiencing respiratory impairment from submersion/ immersion in liquid

• the entrance of the airway is underwater, precluding the breathing of air

• resulting in either death, morbidity or no morbidity

Van Beek et all. A new definition of drowning: towards documentation and prevention of a global public health problem. Bull World Health Organ. 2005;83:853-856

Definition

submersion: airway below surface immersion: airway above surface

Introduction | hypothermia | exhaustion | drowning

Cause of death in recr. divers

Denoble PJ, Caruso JL, deL. Dear G, Pieper CF, Vann RD. Common causes of open-circuit recreational diving fatalities. Undersea Hyperb Med., 2008; 35(6):393-406

Introduction | hypothermia | exhaustion | drowning

Why do divers drown?

drowning

loss of mouthpiece

out of air

trapped in wreck or

cave

increased exertion

Medical condition

O2 toxicity

LOC

too deep

forgot to check

N2 narcosis

Inadequate medical

Lying on self declaration

Inadequate training

Inadequate experience

relative to the particular dive

At the surface????

Equipment malfunction

Introduction | hypothermia | exhaustion | drowning

On the surface……..

• no buoyancy: • empty tank, empty BCD

• not ditching your weights

• BCD does not keep airway free after LOC!

• a well designed life jacket does

• which jacket do you think?

http://www.maritimenz.govt.nz/recreational/safety/lifejackets/lifejacket-types.asp

Introduction | hypothermia | exhaustion | drowning

Lethal triad

drowning

hypothermia exhaustion

Introduction | hypothermia | exhaustion | drowning

• by definition: core temperature < 35o C • measured lower 1/3 of oesophagus

• rectal, bladder, tympanic thermometers are unreliable!

• core temperature drops < 35o C only after 20-30 min after cold water immersion.

• lethal condition!

• however, peripheral cooling is just as lethal!

• evolution has focused on handling hyperthermia and not hypothermia!

Hypothermia Introduction | hypothermia | exhaustion | drowning

In air • 26-30 o C

• naked person

• no sweating or shivering

• still air (no wind)

In water

• 35-35.5 o C

• naked person

• no sweating or shivering

• stagnant water (no swimming)

water vs air thermal conductivity x 24

volume specific heat capacity x 3500

Thermo neutral zone

People cool 4-5 x faster in water compared to air

Introduction | hypothermia | exhaustion | drowning

Cold water immersion

stage 1.

skin cooling

stage 2.

cooling of superficial

nerves and muscle

stage 3.

deep tissue cooling

stage 4.

after effects

cold shock

response:

• hyperventilation

• tachycardia

• hypertension

loss of:

• strength

• sensation

• manual dexterity

hydrostatic & cold

induced diuresis

• neurological

impairment

• arrhythmias

> 30 min

0 – 3 min

3-30 min

Tipton M, Golden F. The physiology of cooling in cold water. In Bierens j (ed) Drowning, prevention rescue and treatment, Springer 2014

aspiration

inability to swim or

grab flotation device

• LOC > drowning

• Lethal

hypothermia

Introduction | hypothermia | exhaustion | drowning

Hypovolemic shock

Cold shock

rapid immersion

T < 15o C

Cold shock response

• cold receptors skin

• sympathetically mediated

• tachycardia

• hypertension

• gasp + hyperventilation

Dive response

• trigeminal nerve stimulation

• + breath holding

• vagal tonus

• bradycardia

• exp. apnoea

• peripheral vasoconstriction

• temporary incapacitation

• swim failure

• importance of life jacket

• 2% arrhythmia

dual activation

sympathetic &

parasympathetic

autonomic conflict

62-82% arrhythmias

• apnoea dive

duration

• high incidence

arrhythmias

Shattock MJ and Tipton MJ. Autonomic conflict: a different way to die during cold water immersion? J Physiol 590 (2012) pp3219-3230

Introduction | hypothermia | exhaustion | drowning

Datta A and Tipton M. Respiratory responses to cold water immersion: neural pathways, interactions, and clinical consequences awake and asleep . J Appl Physiol 2006; 100: 2057–2064

Manual dexterity

• muscle strength • maximum muscle output declines 3%/ 1o C

• is reduced < 27o C (muscle temp)

• which will occur after 20 min in 12o C water

• nerve conduction and amplitude of action potentials • decline < 20o C (nerve temp)

• nerve block at 5-15o C

Vincent MJ, Tipton MJ (1988) The effects of cold immersion and hand protection on grip strength. Aviat Space Environ Med 59:738–741

Introduction | hypothermia | exhaustion | drowning

Central hypothermia

On average 30 min

before onset central

cooling

Introduction | hypothermia | exhaustion | drowning

Rescue collapse

• not due to temperature afterdrop • was based on rectal temp measurements

• rectal conductive heat loss does continue for a while

• does not apply to the heart

• perfusion of extremities is centrally regulated.

• circulatory collapse • hydrostatic and cold water induced diuresis (up to 24% decrease of circulatory plasma volume)

• increased blood viscosity

• removal of constrictive wet suit

• activity by victim

Golden FSC, Hervey GR (1981) The “afterdrop” and death after rescue from immersion in cold water. In: Adam JA (ed) Hypothermia ashore and afl oat. Aberdeen University Press, Aberdeen

Savard GK, Cooper KE, Veale WL et al (1985) Peripheral blood fl ow during rewarming from mild hypothermia in humans. J Appl Physiol 58:4–13

Introduction | hypothermia | exhaustion | drowning

Cold Exposure Survival Model

CESM Input variables

• gender

• age

• BMI

• water temp

• sea state

• clothing

• protective garments

Tikuisis P (1995) Predicting survival time for cold exposure. Int J Biometeorol 39:94–102

Keefe AA, Tikuisis P (2008) A guide to making stochastic and single point predictions using the Cold Exposure Survival Model (CESM). Defence R&D Canada, DRDC Toronto TM 2008–061

swim suit

35 yrs old

rough sea

Introduction | hypothermia | exhaustion | drowning

Natural insulation

Nybo L: Brain temperature and exercise performance. Exp Physiol 2012, 97(3):333–339.

• fat (30%)

• unperfused muscle (70%) > swimming induces heat loss!

Introduction | hypothermia | exhaustion | drowning

Heat preservation Introduction | hypothermia | exhaustion | drowning

• reduced O2 consumption • 6% per 1o C decrease of core temperature

• extreme example: neurologically intact survival after core temp 13.7o C and 6.5 h of resuscitation

• modified BLS • intermittent CPR

• < 20o C: 5 min cpr/ 10 min no cpr

• < 28o C: 5 min on/ 5 min off

• modified ALS • < 30o C: no drugs and only 3 defibrilation attempts

• 30-35o C: double drug interval: adrenaline every 6-10 min, normal defib protocol

Truhlaf A et al. Resuscitation guidelines 2015. Resuscitation 2015;95:148-201

Modifications in CPR Introduction | hypothermia | exhaustion | drowning

Exhaustion

• wave splash

• swimming distance

• arm muscle fatigue

Main limiting factor in cold water swimming is arm muscle fatigue

• muscle cooling (triceps skinfold thickness is predictive)

• decreased muscle perfusion, early onset anaerobic metabolism

• glycogen depletion

Wallingford R, Ducharme MB and Pommier E, factors limiting cold-water swimming distance while wearing personal flotation devices. Eur J Appl Physiol 2000;82:24-29

Introduction | hypothermia | exhaustion | drowning

Metabolic expenditure

Immersion only:

• negative pressure breathing

• central blood pooling (700 ml)

• reduction in static and dynamic lung compliance

• 65% increase work of breathing!

Shivering:

• BMR x 5!

Anaerobic metabolism of cooled

muscle

rapid glycogen

depletion >

exhaustion!

Introduction | hypothermia | exhaustion | drowning

Tipton M and Bradford C. Moving in extreme environments: open water swimming in cold and warm water. Extreme Physiology & Medicine 2014;3:12

Drowning Introduction | hypothermia | exhaustion | drowning

Pathophysiology of drowning

breath holding struggle phase

Alv-cap damage huge pulmonary shunt ↓compliance further drop in PaO2

LOC

aspiration of water (1-2 ml/kg)

involuntary respiratory movements

60 sec PaCO2 up to 6 kPa PaO2 down to 6 kPa

Apnea time training 110-180 sec

diafragm contractions closed glottis, sealed lips

breaking point

temporary reflex laryngospasm

respiratory movements cease

swallowing of water

Bierens J. pathophysiology of drowning. In Drowning, J. Bierens ed, Springer, Heidelberg, 2014

Introduction | hypothermia | exhaustion | drowning

arrhythmias

Graphic representation Introduction | hypothermia | exhaustion | drowning

Cardiopulmonary arrest after drowning

• compared to a cardiac cause of arrest: • younger population • usually in good (cardiac) condition • initial trigger: asphyxia, hypoxia, acidosis,

hypothermia, dive response • and not myocardial ischemia! (blood is still

oxygenated when circulatory arrest occurs, hence the emphasis on cardiac massage)

• VF/VT is rare in cardiac arrest in drowning victims

Hypoxemia Asystole PEA Bradycardia

Vaagenes P, Safar P, Moosy J, et al. Asphyxiation versus ventricular fibrillation cardiac arrest in dogs: differences in cerebral resuscitation effects – a preliminary study. Resuscitation 1997;35:41–52 M. Gilbert, R. Busund, A. Skagseth, Nilsen PÅ, J.P. Solbø Resuscitation from accidental hypothermia of 13.7 degrees C with circulatory arrest Lancet, 355 (2000), pp. 375–376

Introduction | hypothermia | exhaustion | drowning

The unconscious diver

• controlled ascent • victim usually in face down

position • don’t put regulator back in • if in, keep in • controlled ascent with victims BCD

RESCUE COURSE Content: • self-rescue and diver stress • emergency management and

equipment • panicked diver response • in-water rescue breathing protocols • egress (exits) • dive accident scenarios

Introduction | hypothermia | exhaustion | drowning

In water resuscitation

• in water resuscitation • triples the chance of survival! • towing and rescue breaths • cardiac massage not possible! • 5 initial rescue breaths in • If shore is < 5 min away: continue

rescue breaths (10/min) and towing

• If shore> 5 min away: one minute of rescue breaths and bring victim to shore ASAP without further CPR.

Szpilman D. Soares M. In water resuscitation- it is worthwhile. Resuscitation 2004;63:25-31

Introduction | hypothermia | exhaustion | drowning

BLS in drowning

• rescue breaths are difficult • fluid in airway, loss of surfactant • pulmonary edema/ bronchospasm • low compliance, high pressures needed • regurgitation of stomach contents

• not breathing or gasping after drowning

• open airway and give 5 rescue breaths

• ABC in stead of CAB

• O2 administration if possible

• AED is less important! (VF/VT in 10% of cases)

Youn CS, Choi SP, Yim HW. Out-ofhospital cardiac arrest due to drowning: an Utstein Style report of 10 years of experience from St. Mary’s Hospital. Resuscitation 2009;80:778-83.

Introduction | hypothermia | exhaustion | drowning

Aspiration

• submersed active respiration is needed

• dry drowning probably does not exist! • patient was dead before submersion

• rescued before termination of laryngospasm

• lethal volume of aspiration: average of 22 ml/kg seawater (autopsy)

• regurgitation of stomach content:

• 65% rescue breathing only

• 86% full CPR

• also source of aspiration

Lunetta P, Modell JH, Sajantila A. What is the incidence and significance of "Dry-Lungs" in bodies found in water? Am J Forensic Med Pathol. 2004;25:291–301.

Introduction | hypothermia | exhaustion | drowning

Manolios N. Drowning and near drowning on Australian beaches patrolled by life-savers: a ten year study 1973-1983. Med j Austr.1988;148:165-71

Model JH, Graves SA, Ketover A. Clinical course of 91 consequative near-drowning victims. Chest 1976;70:231-8

Ventilation techniques

Mouth to mouth • expired air has

16% O2

• O2 inhalation by rescuer

Pocket mask 02 addition possible Lay man: • 10 min learning curve • 49% failure • poor head extension, jaw

thrust

Bag valve mask lay man: • poor performance • especially single

hand operated

Introduction | hypothermia | exhaustion | drowning

Ventilation techniques

Supra glottic airway devices • I-gel • use by paramedics/

professionals

Endo tracheal tube golden standard in advanced life support

Introduction | hypothermia | exhaustion | drowning

Therapy after ROSC

• symptoms vary from mild cough to ARDS • high flow O2 by mask + reservoir bag • surfactant washout:

• lung protective ventilation • ECLS • Profylactic steroids and antibiotics are not indicated

Calderwood HW, Modell JH, Ruiz BC. The ineffectiveness of steroid therapy for treatment of fresh-water near-drowning. Anesthesiology. 1975 Dec;43(6):642–650.

Cardiac arrest in special circumstances. Resuscitation 95 (2015) 148–201

Introduction | hypothermia | exhaustion | drowning

Extracorporal Life Support (ECLS)

• lung injury: veno-venous ECLS

• refractory cardiac arrest: arterio-venous ECLS

Burke CR, et al. ECLS for victims of drowning. Resuscitation 2016;104:19-23

n=274 ECLS after drowning: overall survival 51%

34% pulmonary only: 71% survival

35% ROSC: 57% survival

31% refractory cardiac arrest: 23% survival

Neurological status post ELS is not reported!

Introduction | hypothermia | exhaustion | drowning

Outcome

Bierens JLM. Drowning. N Engl J Med 2012;366:2102-10.

Introduction | hypothermia | exhaustion | drowning

• all case reports: almost 100% mortality

• motionless submerged diver

• not breathing

• buddy separation > 75%

• BLS is usually initiated

• stopping rules layman BLS: • starts breathing

• impossible to continue (in water)

• healthcare proffesional takes over

• or declares death

LOC and apnea during diving Introduction | hypothermia | exhaustion | drowning

Prolonged survival underwater

rapid brain cooling

8o C in 2 min!

• child

• submersion under ice

• no struggle

• aspiration of water

• swallowing of water

respiratory movements continue for

70 sec following submersion

Fainer DC, Martin CG, Ivy AC (1951) Resuscitation of dogs from fresh water drowning. J Appl Physiol 3:417–426

Conn AW, Miyasaka K, Katayama M et al (1995) A canine study of cold water drowning in fresh versus salt water. Crit Care Med 12:2029–2037

Xu X, Tikuisis P, Giesbrecht G (1999) A mathematical model for human brain cooling during cold-water near-drowning. J Appl Physiol 86:265–272

Outcome after resuscitation beyond 30 minutes in drowned children with cardiac

arrest and hypothermia: Dutch nationwide retrospective cohort study. = poor BMJ 2015;350:h418 | doi: 10.1136/bmj.h418

Introduction | hypothermia | exhaustion | drowning

Samuelson H, Nekludov M and levander M. Neuropsychological outcome following near-drowning in ice water: two adult case studies. J Int Neuropschy soc 2008;14:660-666

? neuropschychological prognosis

Recommended literature

1450470408

N Engl J Med 2012;366:2102-10.

Thank you for listening!

Slides available @ www.mattijnb.nl