The Latest Physiology and Management of Drowned Patients

1. The Latest Physiology and Management of Drowned Patients

2. There were two other people with me!!

3. I’m wet behind the ears for a different reason! • Lifeguard the Vancouver Beaches and pools for 35 years. • Regularly provide training for many aquatic facilities. • Teach surf, waterfront, pool and waterpark lifeguarding. • I have taught lifeguarding in Hawaii, South Africa, Hong Kong and Bangkok. • Taught coast guard aquatic emergency care programs. • Teach remote pre-hospital care to northern fishing resorts.

4. The hardships of teaching in remote fishing camps in Northern British Columbia looking over at the tip of the Alaskan Pan Handle.

5. I’m wet behind the ears for a different reason! • Lifeguard the Vancouver Beaches and pools for 35 years. • Regularly provide training for many aquatic facilities. • Teach surf, waterfront, pool and waterpark lifeguarding. • I have taught lifeguarding in Hawaii, South Africa, Hong Kong and Bangkok. • Taught coast guard aquatic emergency care programs. • Teach remote prehospital care to northern fishing resorts. • I’ve been a paramedic/paramedic educator in Vancouver, full time, since 1979. • Other water experience: ice guarding, ski patrol, distance ocean swimming, triathlon medical coverage, polar bear swims.

6. Vancouver Polar Bear Swim

7. Fastest not the Longest

8. World Drowning Epidemiology • An estimated 500,000 people accidentally drown annually • 2nd leading cause of unintentional injury death • 97% occur in low & middle income countries • Sex ratio M:F 2.2:1 • World rate per 100,000 = 6.8

9. World Drowning Epidemiology • 65% are healthy and under 35 years. • 35% are good swimmers. • 90% occur within 10 yards of safety. • 80-90% of near-drowning patients aspirate. • Various studies report alcohol involvement in 20-79% of cases. In the US, Alcohol use is involved in about 25% to 50% of adolescent and adult deaths associated with water recreation (Howland et al. 1995; Howland and Hingson 1988). Alcohol influences balance, coordination, and judgment, and its effects are heightened by sun exposure and heat (Smith and Kraus 1988).

10. United States Epidemiology • In 2002, there were 3,447 unintentional drownings in the United States, averaging nine people per day. This figure does not include drownings in boating-related incidents (CDC 2004).

11. United States Epidemiology • For every child 14 years and younger who drowns, three receive emergency department care for nonfatal submersion injuries. More than 40% of these children require hospitalization (CDC 2004). Nonfatal incidents can cause brain damage that result in long-term disabilities ranging from memory problems and learning disabilities to the permanent loss of basic functioning (i.e., permanent vegetative state).

12. United States Epidemiology • Boating carries risks for injury. • In 2003, the U.S. Coast Guard received reports for 5,438 boating incidents; 3,888 participants were reported injured and 703 killed in boating incidents. • Among those who drowned, 86% were not wearing life jackets.

13. United States Epidemiology • Most boating fatalities from 2003 (70%) were caused by drowning; the remainder were due to trauma, hypothermia, carbon monoxide poisoning, or other causes. • Alcohol was involved in 31% of reported boating fatalities. • Open motor boats were involved in 42% of all reported incidents, and personal watercraft were involved in another 27% (USCG 2003)

14. Pediatric Drowning Epidemiology • Children under age 5 have the highest mortality rate. • Children less than one year of age most frequently drown in toilets, bathtubs and buckets • Drowning in young children is often associated with a lapse in supervision. Among children ages 1 to 4 years, most drownings occur in residential swimming pools (Brenner et al. 2001). Most young children who drowned in pools were last seen in the home, had been out of sight less than five minutes, and were in the care of one or both parents at the time (Present 1987).

15. Pediatric Drowning Epidemiology • Children with seizure disorders and prolonged QT syndrome are significantly greater risk of drowning.

16. Prolonged QT syndrome • Prolonged QT syndrome, also known as long QT syndrome (LQTS), refers to a group of disorders that increase the risk for sudden death due to an abnormal heartbeat. • Long Q-T syndrome is an infrequent, hereditary disorder of the heart's electrical rhythm that can occur in otherwise-healthy people. It usually affects children or young adults.

17. Prolonged QT syndrome • Problems exist in diagnosing LQTS. • Although the method of diagnosis is the electrocardiogram, most young, healthy people do not routinely undergo this test, and, thus, their first, and possibly fatal, episode of LQTS comes without warning. • In some cases, a non-fatal episode is mistakenly treated as a seizure, and, therefore, a follow-up assessment does not include an electrocardiogram.

18. Prolonged QT syndrome • In addition, some cases of LQTS cannot be diagnosed by a routine electrocardiogram. That is, the QT interval is not found to be prolonged in routine testing. • If LQTS is suspected either because of a previous episode of syncope or because of a family member with LQTS, an exercise electrocardiogram should be performed.

19. Prolonged QT syndrome • In all instances where an individual is diagnosed with LQTS, family members should be thoroughly evaluated, and a detailed family history should be taken noting any individuals with episodes of sudden loss of consciousness and any cases of unexplained sudden death.

20. Canadian Drowning Epidemiology

21. Congress on Drowning 2002

22. Drowning - Definition Drowningis the process of experiencing respiratory impairment from submersion/immersion in liquid • “the definition should include cases of drowning from all kinds of liquid aspirations, except body fluids (vomit, saliva, milk, amniotic fluid)” • Patients may live or die • Regardless of outcome the patient has been involved in a drowning incident

23. Drowning - Definition • Classifications should appear as: • Drowning • Death, Morbidity or No Morbidity • Other features • Pre-existing condition • Hypothermic vs normothermic • Associated Trauma • Respiratory Arrest/Cardiac Arrest

24. Drowning Process Airway in liquid • Breath holding • Liquid in oral pharynx and larynx • Laryngospasm • Hypoxia • Large swallowing of liquid • Aspiration of liquid (amounts variable) • Changes in lungs, body fluids, blood-gas tensions, acid-base balance, and electrolyte concentrations • Hypoxemia

25. Drowning Process • Surfactant washout • Pulmonary hypertension • Shunting • All contribute to Hypoxemia • The patient can be rescued from this cascade of hypoxia at any time during the drowning process

26. SEQUENCE OF EVENTS • Initial period • characteristics of a drowning person • panic • heart and metabolic rate increase • breath holding which leads to respiratory acidosis

27. Respiratory Acidosis Normal body pH is ~7.4 CO2 + H20 H2CO3 HCO- + H+

28. SEQUENCE OF EVENTS The Terminal Gasp Laryngospasm Aspiration

29. laryngospasm • glottic spasm • hypoxia • child vs adult

30. aspiration • pulmonary edema • atelectasis • shunting

31. Pulmonary Edema Reducedperfussion O2 CO2 Alveoli O2 capillary CO2 Interstitial fluid shift

32. Ischemia-Reperfusion MECHANISMS p-selectin ß2 - Integrins Adhesion WBC Tissue damage endothelium

33. Atelectasis collapsed alveoli surfactant Aspiration leads to collapse of the alveoli due to loss of surfactant and pulmonary edema normal alveoli

34. Metabolic Acidosis • Aerobic Metabolism (with O2) • = glycolysis+ Kreb’s cycle • produces 38 ATP • Anaerobic Metabolism (without O2) • produces only 2 ATP (only glycolysis) • does not break down lactic & pyruvic acid, lowers pH

35. Secondary Problems • aspiration may lead to - • unappreciated pulmonary edema • & atelectasis • pulmonary infections (pneumonia) • ARDS

36. Preceding signs and symptoms • initial prolonged spasmodic coughing • dyspnea • inspiratory crackles on auscultation • signs of shock • reduced exercise tolerance • S.O.B. & tachycardia

37. Other Complications or Factors • Hypothermia • Mammalian dive reflex • Drugs and alcohol • Hyponatremia • Cervical spine injuries • Seizures

38. Pulmonary Hypertension • When someone has PH, the pulmonary arteries become narrow or blocked. This means the heart has to work harder to push the blood through the lungs. Over time, the heart cannot keep up. Less blood flows through the lungs to pick up oxygen. This results in PH symptoms such as trouble breathing, dizziness, or feeling tired.

39. Drowning Process • Dry vs Wet • Traditionally this has been used to identify those who have aspirated liquid into the lung and those who have not. • Frequently it is not possible to make this determination • By definition all drowning occurs in liquid and therefore all drowning is wet.

40. Drowning Process • Active vs. Passive vs. Silent drowning • These terms should be abandoned in favor of the terms “witnessed” and “unwitnessed”

41. Drowning Process • Secondary Drowning • This term has been used to describe an unrelated event (seizure, spinal injury, or MI) • This term has also been used to describe the development of ARDS • This term should be abandoned

42. Drowning Process • Drowned and Near-drowned • Have been used for decades to describe outcomes – dead or alive • The term near-drowning has been used to describe patients who have subsequently died from drowning. • Near-drowning should no longer be used • The term Drowned will continue to refer to persons who died from drowning

43. Understand the unique considerations for drowning events in children • Drowning – common etiology of pediatric out-of-hospital cardiac arrest. • Less pulmonary oxygen reserve due to smaller residual volumes • Develop hypoxia/hypoxemia faster due to higher metabolic rate.

44. Understand unique considerations for drowning events in children • Children less likely to have pre-existingillness • Protective Hypothermia more likely in Children. • Effects of Hypothermia are more frequently negative.

45. Even if they dress for the part!

46. Vancouver Polar Bear Swim

47. Understand unique considerations for drowning events in children • Outcomes often closely related to duration of submersion. • Poor outcomes with prolonged submersion • (>25min)

48. Understand unique considerations for drowning events in children • Adolescents tend to endanger themselves by high risk behaviors, including intoxication. • Drowning in children is often a shocking surprise, fast, and emotionally challenging.

49. Prevention of Pediatric Drowning • Educate adults about supervision • Seconds count • Educate our seizure disorder families • Swim and bath with close supervision • Fence or barrier, areas of water • Promote water safety and learn to swim • Train general population in resuscitation

50. Who needs further medical attention after rescue from water? • The following should be sent to hospital • Any loss of consciousness • Any resuscitation (Rescue Breathing or CPR) • Any concurrent condition (seizure, spinal injury, asthma, etc)