Upload
others
View
4
Download
0
Embed Size (px)
Citation preview
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