Drowning is not a helpful diagnosis written on the death certificate

By Dr. CJ Brooks & J. JenkinsSurvival Systems Ltd., Dartmouth, Nova Scotia, Canada

International Association for Safety and Survival Training International Meeting Sydney, Nova Scotia

20th May 2006

IntroductionIntroduction• Death at sea until now has been accepted as an

occupation hazard and fate.

• Herodotus first described death from hypothermia in the Persian/Greek war - 450 BC.

• James Lind described post-rescue collapse in 1762.

• 1794 - Hutchinson’s To preserve the Health and Comfort of Seaman.

• James Currie also noted hypothermia and post rescue collapse in 1797.

2020thth Century Century

• 1914-18 - Drownings– 12 000 Royal Navy sailors– 10 000 British Merchant seaman– 5000 German sailors

Talbot Committee - 1946

• 20,000 – 30,000 officers and men of the Royal Navy died in the Second World War

- One third killed in action- Two thirds died in the survival phase

- Cause of death in the survival phase was drowning and cold water immersion

1950-19751950-1975 Research in the UKResearch in the UK• Commencement of a large series of physiological

experiments and practical field trials.• Key scientists were Hervey and Glaser, Keatinge,

McCance and Pugh. Funding came from the MRC through the RNPRC.– McCance et al.The Hazards to Men in Ships Lost at

Sea 1956 – Nicholl’s Textbook Survival at Sea 1960 – Keatinge’s Textbook Survival in Cold Water 1969– Lee and Lee’s Textbook Safety and Survival at Sea

1971– Smith’s Survival at Sea MRC Report 1976

CONCLUSION that everyone died from hypothermia

1981-The Immersion Incident1981-The Immersion Incident• 4 Stages (Golden and Hervey)

– Initial response (Cold Shock)• Kills within first 3-5 minutes

– Short Term Response (Swimming failure and loss of manual dexterity)

• Kills within first 15 minutes

– Hypothermia • Kills after 30 minutes

– Post Rescue Collapse• Kills anytime during and after the rescue

“Cold Shock”(Tipton, 1989)

Heart Beat

(Beats. Min-1)

Breathing Rate

(Breaths. Min -1)

Breathing Volume

(Litres. Min-1)

Pre-immersion 90 12 16

1st minute of immersion 156 66 114

5th minute of immersion 108 23 67

We are still not doing very well!

• At least 140,000 open water deaths each year (Golden & Tipton, 2002)

A Retrospective Analysis of Drownings Reported to the British Columbia Workers’ Compensation Board

1976 – 2002.By: C.J. Brooks and K.A. Howard

No. Drowned / Accidents

Fishing Logging MVA Misc. Total

No. of Accidents

40 21 14 27 102

No. Drowned

56 22 17 31 106

Loggers (22 accidents)

Cold shock 1

Swimming failure 1

Hypothermia 1

Post-rescue collapse 1

Drowning/Injury/

Entrapment9

Impossible to diagnose

9

Total 22

Re-examination

Drowning = 20 (91%)

Drowning/Injury/Entrapment= 2 (9%)

Basic Information

• 130 fishermen drowned in 89 accidents.

Determined Cause of Death Pre-Investigation

Coroners and accident investigators classified deaths into three categories:

• 113 deaths (87.0%) were classified as “drowning” or “drowning/other”

• 15 deaths (11.5%) were classified as “hypothermia” or “drowning/hypothermia”

• 2 deaths (1.5%) were classified as cardiac event after immersion

Cause of Death after Reclassification

• 7 deaths (5.4%) were reclassified as cold shock• 7 deaths (5.4%) were reclassified as swimming failure• 7 deaths (5.4%) were reclassified as hypothermia• 1 death (0.8%) was reclassified as post rescue collapse• 1 death (0.8%) was reclassified as cardiac event after

immersion• 13 deaths (10.0%) were reclassified as drowning or

drowning with other factors (i.e. entrapment)• 94 deaths (72.2%) were not reclassified due to insufficient

information

Water Temperatures

• Reported in 15 accidents

• Calculated in 67 accidents

• Estimated in 7 accidents

• Water temperatures ranged from 0ºC to 17.5ºC

• In seven cases water temperature was above 15ºC

A Review of the CG-15 Incident Action ReportsHow many incidents investigated by the British

Coast Guard (MCA) are due to drowning, and what was the underlying cause of the drowning death?

Results in both studies were very similar

• Accident investigators, pathologists and coroners had:

(a) little knowledge of cold water physiology

(b) tended to work in isolation of each other

• There were many pages of technical information but only single sentences on the human factors and cause of death

Results cont’

• Critical testimony that might lead to the underlying cause of drowning either was not asked, not recorded or simply glossed over with such words as “ drowning”, “drowning exposure”, “drowning/hypothermia”, or“undetermined”

• Critical physical and physiological information eg. swimming ability, water temperature, hospital admission, core temperature, wearing of flotation devices or survival suits was missing in nearly every case.

• All their technical data was meticulously recorded

• But there was very little detail on the medical/human factors portion of the inquiry

• There was not enough information to determine the underlying cause of drowning in any of the UK cases and only 35 of the Canadian fishermen’s deaths.

Conclusions and Recommendations

• Accident investigation needs to be done as a team• The team needs to know about cold water physiology

and the requirement to take a good incident history• A checklist has been developed to assist anyone

involved in a drowning death (see Annex of paper)• In Canada, we lectured to BC coroners and

pathologists and to the UK gave a full confidential report to the MCA

• Only in the next analysis after more precise data is recorded will it be possible to determine the underlying causes of drowning