1. Gary Williams Mini PAC Conference , Melbourne 16-17 November 2012
Drowning: an Update 2012
Gary Williams
Mini PAC Conference , Melbourne
16-17 November 2012

2. Plan Definitions Guidelines Epidemiology Pathophysiology Management
Outcome prediction

3. Definition
2002, World Congress on Drowning, Amsterdam: “respiratory embarrassment from submersion / immersion in a liquid medium”
“near drowning”
“dry or wet drowning”
“secondary drowning”
“delayed onset respiratory distress”

4. Drowning: Aust Resus Council
Victim rolled to side during initial checking, airway clearance and initial breathing check
Begin EAR in water if immediate exit not possible
If hypothermic, attempt resuscitation even after possibly prolonged immersion
Last updated Feb 2005

5. Drowning: ERC 2010 Update
More research comparing OHCA due to drowning with primary cardiac OHCA needed
In-water EAR if victim unresponsive, breaths in 1 minute then decide based on est time to shore
< 5 mins continue EAR while towing
> 5 mins give 1 more minute EAR then head off uninterrupted
Early intubation with cuffed ETT, not LMA or Guedel
Use ECG, ET CO2 or echo to confirm arrest. Be wary to discontinue resus efforts in the field
Core temp < 30C : limit defib to x3 and withold drugs till core temp > 30C
Recommends rewarming hypothermic patient to 32-34C and avoid temps >37C during subsequent intensive care course

6. Drowning: AHA / ILCOR 2010
Mouth to nose EAR by swimmer while retrieving
When ALS commenced traditional A-B-C sequence used
In hypothermic patient value of deferring subsequent defib attempts or resuscitation drugs “controversial” and “reasonable to consider…. according to standard algorithm…concurrent with rewarming strategies”
Use ETCO2 to monitor effectiveness, ROSC and avoid hyperventilation
32-34C “may be considered” for children who remain comatose after ROSC
Avoid rewarming faster than 0.5C per 2 hours and treat fever (>38C) aggressively with antipyretics and cooling devices

7. Age-standardised Disability-Adjusted Life Year (DALY) rates from Drownings by country (per 100,000 inhabitants)
< 100
>700

10. National Drowning Report, RLSA, 2011

11. National Drowning Report, RLSA, 2011

12. National Drowning Report, RLSA, 2011

13. National Drowning Report, RLSA, 2011

14. ANZPIC Registry

15. PICU Admissions, Drowning, 2000-2011
ANZPIC Registry

16. PICU Admissions, Drowning by Age Category 2000-2011
ANZPIC Registry

17. National Drowning Report, RLSA, 2011

18. National Drowning Report, RLSA, 2011

19. National Drowning Report, RLSA, 2011

20. PICU Admissions Deaths Drowning, 2000-2011
ANZPIC Registry

21. Predictors of Death or Severe Neur Impairment After Submersion
At site of submersion
Immersion duration > 10’
Delay in commencement of CPR
In the ED
Asystole on arrival or CPR duration > 25’
Fixed and dilated pupils and GCS < 5
Fixed and dilated pupils and arterial pH < 7
In the ICU
No spontaneous purposeful movements and abnormal brainstem function 24h after immersion
Abnormal CT scan within 36h of submersion
Oh’s Intensive Care Manual, 6th Ed 2009

22. PICU LOS Drowning
ANZPIC Registry

23. Drowning Pathophysiology: Pulmonary
Aspirate small amounts, usu ,22ml/kg
Fluid shifts
Aspiration of debris
Infection (rare)
Surfactant depletion
Pulmonary oedema, pneumonia (25-50%), ARDS < 10%
Neurogenic
Altered capillary permeability
Forced inspiration against a closed glottis
Surfactant dysfunction

25. Pathophysiology: Cardiac
Potential role of “molecular autopsy” in unexplained drownings ?cardiac channelopathy
Mayo Clinic 2011: 35 unexplained drownings, average age 17y, 23 male 12 female  putative pathogenic mutation in 1/3: 3 LQT S, 6 CPVT
More common in females with 5/8 unexplained “swimming-related” drownings in females having mutation
< 10% of drownings, implications for family
In retrospect 50% had warning sign on history

26. Presentation and outcome of water-related events in children with LQT syndrome
Albertella et al, ADC, Aug 2011

27. OHCA Drowning V Primary Cardiac
Claesson et al, Resuscitation, 2008

28. OHCA Drowning Vs Primary Cardiac
Grmec et al, Int J Emerg Med 2009

30. Could water temperature be protective?
Animal data that brain cooling before HI event ↓ neuronal injury
Diving Reflex: ↓HR, ↑SVR, ↓Qskin ↓Qmuscle ↓Qgut ↓Qkidney ↓Qmyocardial with CBF preserved maybe even ↑ by evolving hypercarbia
Colder the water  more profound is reflex
No evidence stronger in the young
Immersion-induced apnoea: prevents heat exchange through the lungs before hypoxia intervenes

31. Could water temperature be protective?
Q: How cool has deep brain got to be and how quickly while hypoxia is developing?
A: Unknown
Animal data (rat) suggests 33C in <5’, probably 30C in <10’
Mathematical model of human hippocampus temp on exposure to water at 2C

32. A proposed decision making rule for search, rescue and resuscitation of submersion victims
Tipton and Golden, Resuscitation, 2011
Submersions > 4 min, age, water temp, deep body temp, duration of submersion and good neurologic outcome
43 cases, all with water temp documented
Submersion time in 40/43
37/43 initial deep body temp available: < 30C in30/37 (80%)

33. A proposed decision making rule for search, rescue and resuscitation of submersion victims
Tipton and Golden, Resuscitation, 2011

34. Submersion Duration & Risk of Death or Severe Neur Impairment
Quan et al, Peds, Oct 1990

35. Christensen et al, Peds, May 1997

36. Impact of age, submersion time and water temp on outcome in near drowning Suominen et al, Resuscitation 2002
Finland regional survey – most drownings occur in cold water
61 admissions to ICU Helsinki over 12 y: water temp, rectal temp, and estimated submersion time
Median water temp 17C (range 0-33)…lower in survivors but much cross over
80% admission temp < 35C (no diff S & NS)
Est submersion time only independent predictor of survival (5’ V 16’) but no clear cut off could be defined

40. Seasonal River Temperatures around Sydney

41. ED Prediction of outcome ?
Even fixed and dilated pupils, low GCS, need for CPR in ED have proven unreliable in individual cases
Christensen et al (Peds, 1997): composite score based on ED physical exam (apnoea, coma) + need for CPR + lowest pH …..best available ……but even this 93% accurate in their hands

42. ED Prediction of outcome ?

43. ICU Prediction of Outcome ?
PE: GCS ≥ 6 or purposeful movement + intact brainstem reflexes  v likely good outcome
SEPS: absent SEPS 100% predictive of poor outcome
Imaging:
Early (8h) abnormal CT strongly predictive for bad outcome; normal CT uninformative
MRI more specific but need 3-4 days to avoid inappropriate optimism

45. CT scans of 156 children admitted to ICU with drowning
Cranial CT Findings in a large group of children with drowning; diagnostic, prognostic and forensic implications Rafaat et al, PCCM 2008
CT scans of 156 children admitted to ICU with drowning
Abnormalities mostly diffuse ↓ GWD or LDC BG
Early (8h) abnormal scan = bad outcome (28/28 died)
Early normal and later abnormal scan the same outcome (23/24)
All abnormal scans in children with GCS 3 or 4 post resuscitation: if GCS higher no need to scan
Normal scan uninformative

46. Drowning: PICU Management
Ventilation: normocapnia, optimise oxygenation, minimise VILI
Circulation: fluids, inotropes, monitoring to optimise haemodynamics, perfusion
Prophylactic anticonvulsants? No evidence
Continuous EEG monitoring of unconscious pt
Glucocorticoids? No evidence (Foex, ADC, 2002) ?↑infection, ?? role later if ARDS
Prophylactic antibiotics? No evidence (Wood, ADC, 2010) even with CXR changes…selects resistant bugs
Therapeutic Hypotherrmia “Cooling” ?

47. Moler et al, CCM, 2011

48. THAPCA Paed OHCA 32-34C for 48h then 36-37.5C for 3d Within 6h of ROSC
* Drowning victims with core temp <32C on arrival specifically excluded

49. Reasons to be “circumspect”
Fever common, bad for injured brain, often not controlled to normothermia in control arms
TH does have risks
Two large retrospective studies in paed cardiac arrest (Pittsburgh n=181, CCTG n=222) have not shown benefit
Data on early prophylactic use of TH in TBI in children suggesting a worse outcome

50. Hutchinson et al, NEJM, June 2008

51. Summary Drowning remains a major cause death and disability
Accurate outcome prediction in field and ED problematic
Cold water protection theoretically feasible but little evidence to support
Therapeutic hypothermia still waiting for good evidence to support

52. Questions ?

53. “Drowning” by Ken Done

54. Drowning Pathophysiology: Pulmonary
Aspirate small amounts, usu ,22ml/kg
Fluid shifts
Aspiration of debris
Infection (rare)
Surfactant depletion
Pulmonary oedema, pneumonia (25-50%), ARDS < 10%
Neurogenic
Altered capillary permeability
Forced inspiration against a closed glottis
Surfactant dysfunction

56. Pathophysiology: Cardiac
Potential role of “molecular autopsy” in unexplained drownings ?cardiac channelopathy
Mayo Clinic 2011: 35 unexplained drownings, average age 17y, 23 male 12 female  putative pathogenic mutation in 1/3: 3 LQT S, 6 CPVT
More common in females with 5/8 unexplained “swimming-related” drownings in females having mutation
< 10% of drownings, implications for family
In retrospect 50% had warning sign on history

57. Presentation and outcome of water-related events in children with LQT syndrome
Albertella et al, ADC, Aug 2011

58. OHCA Drowning V Primary Cardiac
Claesson et al, Resuscitation, 2008

59. OHCA Drowning Vs Primary Cardiac
Grmec et al, Int J Emerg Med 2009