Environmental Emergencies II
Nicholas E. Kman, MD FACEP
Associate Professor
The Ohio State University
Department of Emerge...
Objectives
 Learner will review the following topics:
 Snake Envenomations
 Spider Bites
 Marine Envenomations
 Drown...
Snake Envenomations
Snake Envenomations
Snake Bites
 9,000 snakebites annually in U.S. with 2,000 treated
as envenomations
 Est. 2.5 million venomous snakebites...
Snake Bites
Statistics
 Crotalinae – 99% of venomous snakebites in U.S.
 65% - rattlesnakes
 25% - copperheads
 10% - ...
Snake Bites
Species of Snakes
 Viperidae - rattlesnakes, cottonmouth, copperhead
(pit-vipers)
 Elapidae - coral snake on...
Coral Snake (Elapidae)
 Only 1/100 bites in U.S.
annually
 Distinct red band bordered by
yellow stripes
 Neurotoxic com...
Coral Snake (Elapidae)
 Effects may be delayed up to 12 hrs
 Mild envenomation:
 localized swelling only
 Severe enven...
Coral Snake (Elapidae)
 Initial appearance may be innocuous
 Early evacuation to prepare for antivenom
administration
 ...
N Engl J Med, Vol. 347, No.
5·August 1, 2002
Signs and Symptoms
 Check for signs of envenomation:
1 or more fang marks, pain, edema, erythema, or
ecchymosis. Bullae m...
Snake Bites
Grades of Envenomation
 Grade 0
 Fang marks
 No envenomation
 Grade I
 "Mild" envenomation
 Fang marks
...
Moderate
 56% of bites
 Severe pain
 Spreading edema beyond
site of bite
 Systemic signs – nausea,
vomiting, paresthes...
Severe
• Marked swelling of extremity that occurs rapidly
• Subcutaneous ecchymosis
• Systemic symptoms – coagulopathy,
hy...
Lavonas et al. BMC Emergency Medicine 2011, 11:
SNAKE BITES
Management
 Maintain vital signs (ABC’s)
 Reduce venom effects
 Prevent complicated sequelae
 Minimize tis...
SNAKE BITES
Immediate First Aid
 Get away from the snake
 Stay calm
 Immobilize the bitten extremity at a
position of h...
SNAKE BITES
 Treatments to Avoid in (Pit Viper) Snakebite
 Cutting and/or suctioning of wound
 Ice
 NSAIDs
 Prophylac...
SNAKE BITES
ED Management
 Notify Regional Poison Center
 ABC’s
 At least 1 IV line, draw labs while starting
 If no s...
Snake Bite Antivenin
 Polyvalent Crotalinae antivenin
 Available in U.S. since 1947
 Mainstay of medical management
 H...
SNAKE BITES
Ovine (Sheep Derived) Fab Antivenin (CroFab)
 Mix 4-6 vials in 250ml of NS
 Additional 4-6 vials until contr...
SNAKE BITES
Other Management
 Cleanse wound thoroughly
 Tetanus prophylaxis
 General supportive care
 Opioid Analgesics
SNAKE BITES
Complications
 Compartment syndrome – surgery is rarely indicated; if
worried, do pressure monitoring
 Serum...
Quiz
 A 23 year old male was playing with a copperhead
when he was surprisingly bit. He had premedicated
with about “elev...
Quiz
 A 23 year old male was playing with a copperhead
when he was surprisingly bit. He had premedicated
with about “elev...
Spider Envenomations
Ohio’s Biting Spiders
 2 main groups of spiders; the recluse spiders and the
widow spiders.
 The black widow, Latrodectu...
Widow Spiders
• Black Widow – Latrodectus mactans
• Widespread, esp. SE/SW
• Garages, barns, outhouses, foliage
• Alpha-la...
Black Widow
• Initial bite may be no more than a prick
• Within 30 min – systemic symptoms
• Muscle cramping – local to la...
Black Widow
 May mimic an acute abdomen
 Hypertension, tachycardia
 Latrodectus facies – spasm of
facial muscles, edema...
Treatment
 Ice to bite site
 Pain medication
 Benzodiazepines for muscle spasm
 Calcium gluconate no longer recommende...
Brown Recluse
• Loxosceles reclusa
• Coast to coast
• Attics, closets,
woodpiles, storage
sheds
• Violin-shaped marking
• ...
Cutaneous Loxoscelism
 Initially a sharp stinging sensation, some report
no awareness of being bitten
 Over 2-8 hrs achi...
Brown Recluse Venom
 Cytotoxic enyzmes cause destruction of local cell
membranes:
 Alkaline phosphatase
 5-ribonucleoti...
Brown Recluse
Treatment
 Immobilization, ice, elevation
 Tetanus prophylaxis
 Antihistamines
 Dapsone?
 Skin grafting once area has...
Systemic Loxoscelism
 Rarely correlates with the severity of the skin
lesion
 Children most at risk
 Fever, chills, mya...
Quiz
 A 19 year old male is reaching into a tackle box
when he feels a prick. He thought he poked himself
with a fishing ...
Quiz
 A 19 year old male is reaching into a tackle box
when he feels a prick. He thought he poked himself
with a fishing ...
Marine Envenomations
Jellyfish
 Coelenterates (Portuguese man-of-war, true jellyfish,
hydroid corals, sea anemones, corals)
 Coastal areas of...
Jellyfish
 Toxin contains complex mixture of proteins and
polypeptides
 Most common presentation is painful papular-
urt...
45
46
Jellyfish
 Systemic reactions can develop – weakness,
headache, vomiting, muscle spasm, fever, pallor,
respiratory distre...
Treatment
 ABCs
 Inactivate nematocysts
 Remove
Jellyfish Treatment
 Rinse with saltwater
 Remove tentacles with protected hand
 Pour acetic acid (vinegar) on it to in...
Removal
 Wear gloves for protection
 Apply shaving cream, baking soda paste
 Shave with razor or other sharp edge
 Tet...
Echinoderms
• Sea urchins, starfish, sea cucumbers
• Venoms usually contained in spines
• Local effects most common
• Syst...
Echinoderms
 Remove visible spines
 Immersion in hot water for 30-90 minutes
 Local or regional anesthesia if hot water...
Quiz
 A patient presents to your emergency department
after being stung by a jellyfish. At the scene life
guard treated w...
Quiz
 A patient presents to your emergency department
after being stung by a jellyfish. At the scene life
guard treated w...
Drowning
The Eve Method
August 1946 copy of Popular Science
Szpilman D, Bierens J, Handley A, Orlowski J. Drowning. N Engl J Med. 2012;366(22):2102-10.
Terminology
 Drowning: Process resulting in respiratory impairment
from submersion / immersion in liquid medium. Victim
m...
Drowning
 Second only to MVA as most common cause of
accidental death in US
 Risk factors:
 male sex
 age <14 years
 ...
Drowning Pathophysiology
 Most important abnormality of drowning is a
profound HYPOXEMIA resulting from asphyxia.
 Seque...
Drowning Treatment
 Immediate and adequate resuscitation is most
important factor influencing survival.
 For unconscious...
Predictors of Outcome
 Early BLS and ACLS improve outcomes (ABC’s)
 Duration of submersion and risk of death/severe
neur...
Diving Medicine
Dysbarism
 All the pathologic changes caused by altered
environmental pressure
 Altitude-related event
 Underwater divi...
Types
 Barotrauma – dysbarism from trapped gases
 Decompression sickness – dysbarism from
evolved gases
 Nitrogen narco...
Pressure is doubled, volume is halved.
PV = K Every 33 ft of descent increases the pressure by 1 atm.
Boyle’s Bubbles
 Boyle’s law states: pressure of gas is inversely
related to its volume.
 As pressure increases with des...
Middle Ear Squeeze
 Barotitis media-Most common
diving-related barotrauma
 Equalization of pressure via
eustachian tube ...
Middle Ear Squeeze
 PE – erythema or retraction of TM, blood behind
TM or rupture, bloody nasal discharge
 Reverse ear s...
Other Barotrauma
 Barotitis externa
 Alternobaric vertigo
 Barosinusitis
 Barodontalgia
 Face mask squeeze
Pulmonary Over-Pressurization
 A too-rapid ascent
 Lung emptying is incomplete
 Lung volume expands rapidly
 Pneumotho...
Arterial Gas Embolism (AGE)
 Results from air bubbles entering pulmonary
venous circulation from ruptured alveoli
 Usual...
AGE
Vann, RD.; Butler, FK.; Mitchell, SJ.; Moon, RE.
“Decompression illness.” The Lancet, v. 377 issue 9760,
2011, p. 153-...
Arterial Gas Embolism (AGE)
 Recompression in hyperbaric chamber
 Transport supine, not in Trendelenburg
 100% oxygen, ...
Decompression Sickness (DCS)
 Henry’s Law – the amount of a gas that will
dissolve in a liquid is proportional to partial...
Decompression Sickness
 During a slow ascent, pressure decreases,
nitrogen in the tissues is released into blood and
alve...
Type I DCS
 “The Bends” – periarticular joint pain is most
common symptom of DCS
 Shoulders and elbows most often affect...
Type I DCS
 Cutaneous – pruritus, cutis marmorata,
hyperemia, orange peel
 Lymphedema
 Fatigue, especially if severe
Va...
Type II DCS
 Pulmonary system (The Chokes)
 Nervous system (The Staggers)
 Decompression shock
Cerebral AGE vs. DCS II
 Cerebral AGE
 May occur after any type
of dive
 Onset is immediate (<10-
120 min)
 Only brain...
Pulmonary DCS
 “The Chokes”
 May begin immediately after dive but often takes up
to 12 hours to develop
 Triad – shortn...
Neurologic DCS
 Spinal cord is the most common site affected
 Lower thoracic and lumbar regions
 Low back pain, “heavin...
Decompression Shock
 Vasomotor decompression sickness
 Rapid shift of fluid from intravascular to extravascular
spaces (...
DCS Diagnostics
 History is most important
 Lab used to rule out other conditions and/or obtain
baseline measurements
 ...
DCS Treatment
 ABCs
 Transport supine, not Trendelenburg
 100% oxygen
 IVF
 Recompression therapy
 Divers Alert Netw...
Quiz
 You are on a plane from Key West to Cleveland when the
passenger next to you starts to arch his back and bend
his k...
Quiz
 You are on a plane from Key West to Cleveland when the
passenger next to you starts to arch his back and bend
his k...
High Altitude Medicine
High Altitude Illness
 Rate of ascent
 Altitude reached
 Sleeping altitude
 Individual physiology
High Altitude Illness
 Rate of ascent: Graded ascent is safest method
to facilitate acclimatization and prevent sickness....
Risk Factors
 History of high altitude illness
 Residence at altitude below 900 m
 Exertion
 Preexisting cardiopulmona...
High Altitude Medicine
 Acute Mountain Sickness (AMS)
 High Altitude Cerebral Edema (HACE)
 High Altitude Pulmonary Ede...
Acute Mountain Sickness
 History is key (total elevation gain and rate of gain)
 AMS is present if one is at altitude an...
AMS
 Hypoxia
 Neurohumeral and hemodynamic responses
 Overperfusion of microvascular beds
 Elevated hydrostatic capill...
AMS
 Avoid further ascent until symptoms have resolved
 Descend if no improvement in 24 hours or worsening
symptoms
 No...
Acetazolamide
 For both treatment and prevention of AMS
 Mechanism of action: increase urinary excretion of
sodium, pota...
Acetazolamide
 Speeds up acclimatization
 250 mg po bid for treatment
 125-250 mg po bid starting 24 hr before ascent a...
Dexamethasone
 For treatment or prevention of AMS
 Does NOT speed up acclimatization
 May improve integrity of blood-br...
http://www.jyi.org/issue/on-the-mountains-high-altitude-sickness-in-nepal/
High Altitude Cerebral Edema (HACE)
 HACE: progression of AMS to life-threatening
end-organ damage.
 Defined as severe A...
HACE
 Progression of AMS
 Ataxia is the single most useful sign
 Diffuse neurologic dysfunction
 Altered mental status...
http://www.altitudemedicine.org/index.php/altitude-medicine/learn-about-altitude-sickness/what-is-hace
HACE Treatment
 Descend
 Descend !
 Descend !!
 Oxygen
 Dexamethasone 8 mg load followed by 4 mg every 6
hrs
 Gamow ...
HAPE
 Accounts for most deaths from high altitude illness
 Non-cardiogenic pulmonary edema
 Commonly strikes the second...
HAPE
 Early diagnosis is crucial to recovery
 Decreased exercise performance
 Dry cough initially
 Tachycardia and tac...
HAPE
Patient admitted with
progressive respiratory
distress 24 hours after
arriving at town at 2700
meters above sea level...
HAPE
 Pulmonary hypertension due to hypoxic pulmonary
vasoconstriction
 Elevated capillary pressure
 Stress failure of ...
HAPE Treatment
 Descent is treatment of choice
 Exertion may worsen the illness
 Oxygen
 Gamow bag if unable to descen...
http://www.jyi.org/issue/on-the-mountains-high-altitude-sickness-in-nepal/
Quiz
 You decide to climb to the top of Mt. Everest. While
nearing the top, your partner begins to have a
seizure and bec...
Quiz
 You decide to climb to the top of Mt. Everest. While
nearing the top, your partner begins to have a
seizure and bec...
Questions?
Ohio ACEP Board Review: Environmental Emergencies II
Ohio ACEP Board Review: Environmental Emergencies II
Ohio ACEP Board Review: Environmental Emergencies II
Ohio ACEP Board Review: Environmental Emergencies II
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Ohio ACEP Board Review: Environmental Emergencies II

  1. 1. Environmental Emergencies II Nicholas E. Kman, MD FACEP Associate Professor The Ohio State University Department of Emergency Medicine
  2. 2. Objectives  Learner will review the following topics:  Snake Envenomations  Spider Bites  Marine Envenomations  Drowning  Dysbarism Dive Medicine High Altitude Illness
  3. 3. Snake Envenomations
  4. 4. Snake Envenomations
  5. 5. Snake Bites  9,000 snakebites annually in U.S. with 2,000 treated as envenomations  Est. 2.5 million venomous snakebites occur internationally, with 125,000 deaths annually.  About 12 deaths/year in U.S.  60% rattlesnakes  Important to know distribution of venomous snakes in your area Lavonas et al. BMC Emergency Medicine 2011, 11:
  6. 6. Snake Bites Statistics  Crotalinae – 99% of venomous snakebites in U.S.  65% - rattlesnakes  25% - copperheads  10% - cottonmouths
  7. 7. Snake Bites Species of Snakes  Viperidae - rattlesnakes, cottonmouth, copperhead (pit-vipers)  Elapidae - coral snake only member in U.S.; others include cobra and sea snakes Rattlesnakes CopperheadCottonmouth Pit Viper
  8. 8. Coral Snake (Elapidae)  Only 1/100 bites in U.S. annually  Distinct red band bordered by yellow stripes  Neurotoxic component to their potent venom  Short fixed fangs making it difficult to envenomate humans
  9. 9. Coral Snake (Elapidae)  Effects may be delayed up to 12 hrs  Mild envenomation:  localized swelling only  Severe envenomation:  Any systemic symptoms  Nausea, vomiting, headache, mental status, neurologic  Respiratory distress
  10. 10. Coral Snake (Elapidae)  Initial appearance may be innocuous  Early evacuation to prepare for antivenom administration  Evacuate ALL patients with elapidae bites, regardless of symptoms
  11. 11. N Engl J Med, Vol. 347, No. 5·August 1, 2002
  12. 12. Signs and Symptoms  Check for signs of envenomation: 1 or more fang marks, pain, edema, erythema, or ecchymosis. Bullae may appear.  Systemic effects: AMS, tachycardia, tachypnea, resp distress, hypotension, coagulopathy, renal failure, hemolysis.
  13. 13. Snake Bites Grades of Envenomation  Grade 0  Fang marks  No envenomation  Grade I  "Mild" envenomation  Fang marks  Pain and edema at site  Local ecchymosis  Blistering  Necrosis  Minimal to no spread of edema proximal to site Torpy, Janet M (04/18/2012). "Snakebite". JAMA : the journal of the American Medical Association (0098-7484), 307 (15), p. 1657.
  14. 14. Moderate  56% of bites  Severe pain  Spreading edema beyond site of bite  Systemic signs – nausea, vomiting, paresthesias, muscle fasciculations, mild hypotension Photo by N. Kman
  15. 15. Severe • Marked swelling of extremity that occurs rapidly • Subcutaneous ecchymosis • Systemic symptoms – coagulopathy, hypotension, altered mental status
  16. 16. Lavonas et al. BMC Emergency Medicine 2011, 11:
  17. 17. SNAKE BITES Management  Maintain vital signs (ABC’s)  Reduce venom effects  Prevent complicated sequelae  Minimize tissue damage
  18. 18. SNAKE BITES Immediate First Aid  Get away from the snake  Stay calm  Immobilize the bitten extremity at a position of heart  Apply a constricting band (Coral Snake)  TRANSPORT TO MEDICAL FACILITY http://www.howitworksdaily.com/environment/how-to-survive-a-snakebite/
  19. 19. SNAKE BITES  Treatments to Avoid in (Pit Viper) Snakebite  Cutting and/or suctioning of wound  Ice  NSAIDs  Prophylactic antibiotics or fasciotomy  Routine use of blood products  Shock therapy (electricity)  Steroids (except for allergic phenomena)  Tourniquets Lavonas et al. BMC Emergency Medicine 2011, 11:
  20. 20. SNAKE BITES ED Management  Notify Regional Poison Center  ABC’s  At least 1 IV line, draw labs while starting  If no signs of envenomation, observe 8 hours for further progression  Measure circumference of limb, mark leading edge every 15-30 minutes  If signs of envenomation, antivenin admin.
  21. 21. Snake Bite Antivenin  Polyvalent Crotalinae antivenin  Available in U.S. since 1947  Mainstay of medical management  Horse serum derived  Dosing varies according to severity  Production discontinued in 2002
  22. 22. SNAKE BITES Ovine (Sheep Derived) Fab Antivenin (CroFab)  Mix 4-6 vials in 250ml of NS  Additional 4-6 vials until control achieved  Scheduled 2-vial doses at 6, 12, and 18 hr  Initial dose given slowly for first 10 min  Rest of dose over 1 hr
  23. 23. SNAKE BITES Other Management  Cleanse wound thoroughly  Tetanus prophylaxis  General supportive care  Opioid Analgesics
  24. 24. SNAKE BITES Complications  Compartment syndrome – surgery is rarely indicated; if worried, do pressure monitoring  Serum sickness (type III hypersensitivity) – up to 3 weeks after antivenin; fever, chills, arthralgias, diffuse rash  Rx-steroids and antihistamines
  25. 25. Quiz  A 23 year old male was playing with a copperhead when he was surprisingly bit. He had premedicated with about “eleventeen” beers. He is complaining of severe pain, spreading edema, and has mild hypotension. What is the best treatment?  A. Lecture on the dangers of mixing snakes and alcohol  B. 4 Vials of CroFab Antivenin  C. 2 Vials of Horse Serum Derived Antivenin  D. Applying oral suction to the bite site
  26. 26. Quiz  A 23 year old male was playing with a copperhead when he was surprisingly bit. He had premedicated with about “eleventeen” beers. He is complaining of severe pain, spreading edema, and has mild hypotension. What is the best treatment?  A. Lecture on the dangers of mixing snakes and alcohol  B. 4 Vials of CroFab Antivenin  C. 2 Vials of Horse Serum Derived Antivenin  D. Applying oral suction to the bite site
  27. 27. Spider Envenomations
  28. 28. Ohio’s Biting Spiders  2 main groups of spiders; the recluse spiders and the widow spiders.  The black widow, Latrodectus mactans, and the northern widow, Latrodectus variolus.
  29. 29. Widow Spiders • Black Widow – Latrodectus mactans • Widespread, esp. SE/SW • Garages, barns, outhouses, foliage • Alpha-latrotoxin: causes increased release of multiple neurotransmitters
  30. 30. Black Widow • Initial bite may be no more than a prick • Within 30 min – systemic symptoms • Muscle cramping – local to large groups such as abdomen, back, chest, thighs • Nausea, vomiting
  31. 31. Black Widow  May mimic an acute abdomen  Hypertension, tachycardia  Latrodectus facies – spasm of facial muscles, edematous eyelids  Priapism, weakness, diaphoresis, fasciculations may all occur in severe envenomation
  32. 32. Treatment  Ice to bite site  Pain medication  Benzodiazepines for muscle spasm  Calcium gluconate no longer recommended  Tetanus prophylaxis  Antivenin – for severe symptoms not relieved by above measures, esp. hypertension; pregnancy
  33. 33. Brown Recluse • Loxosceles reclusa • Coast to coast • Attics, closets, woodpiles, storage sheds • Violin-shaped marking • Cytotoxic • Necrotic arachnidism • Local and systemic effects
  34. 34. Cutaneous Loxoscelism  Initially a sharp stinging sensation, some report no awareness of being bitten  Over 2-8 hrs aching and itching develop  Bulls-eye lesion: erythema surrounds vesicle circumscribed by a ring or halo of pallor  Necrosis may develop within 3-4 days, becoming ulcerated
  35. 35. Brown Recluse Venom  Cytotoxic enyzmes cause destruction of local cell membranes:  Alkaline phosphatase  5-ribonucleotide phosphohydrolase  Esterase  Hyaluronidase  SPHINGOMYELINASE D
  36. 36. Brown Recluse
  37. 37. Treatment  Immobilization, ice, elevation  Tetanus prophylaxis  Antihistamines  Dapsone?  Skin grafting once area has demarcated  Antivenin - research
  38. 38. Systemic Loxoscelism  Rarely correlates with the severity of the skin lesion  Children most at risk  Fever, chills, myalgias, arthralgias, morbilliform rash  DIC, seizures, renal failure, hemolysis  Steroids may decrease amount of hemolysis  Alkalinize urine
  39. 39. Quiz  A 19 year old male is reaching into a tackle box when he feels a prick. He thought he poked himself with a fishing lure, but becomes nauseated and presents complaining of severe abdominal pain. On exam, his abdomen is rigid and tender. What is the next best treatment?  A. Exploratory Laporatomy  B. Calcium Gluconate  C. Dapsone  D. Analgesics and Benzos for muscle spasm and pain
  40. 40. Quiz  A 19 year old male is reaching into a tackle box when he feels a prick. He thought he poked himself with a fishing lure, but becomes nauseated and presents complaining of severe abdominal pain. On exam, his abdomen is rigid and tender. What is the next best treatment?  A. Exploratory Laporatomy  B. Calcium Gluconate  C. Dapsone  D. Analgesics and Benzos for muscle spasm and pain
  41. 41. Marine Envenomations
  42. 42. Jellyfish  Coelenterates (Portuguese man-of-war, true jellyfish, hydroid corals, sea anemones, corals)  Coastal areas of U.S.  About 10,000 envenomations each summer off the east coast of Australia  Nematocysts are stinging cells on outer tentacle  Box jellyfish causes most fatal envenomations
  43. 43. Jellyfish  Toxin contains complex mixture of proteins and polypeptides  Most common presentation is painful papular- urticarial eruption  Lesions can last for minutes to hours, and rash may progress to urticaria, hemorrhage, ulceration
  44. 44. 45
  45. 45. 46
  46. 46. Jellyfish  Systemic reactions can develop – weakness, headache, vomiting, muscle spasm, fever, pallor, respiratory distress, paresthesias  Seabather’s eruption – intensely pruritic maculopapular eruption on skin that has been covered by swimwear – larvae of thimble jellyfish; develops within 24 hrs of exposure and lasts 3-5 days http://www.sdtn.com/dive_resources/technical_articles/sea- bathers-eruption-and-seaweed-dermatitis-whats- difference#.U-5b8fldV8E
  47. 47. Treatment  ABCs  Inactivate nematocysts  Remove
  48. 48. Jellyfish Treatment  Rinse with saltwater  Remove tentacles with protected hand  Pour acetic acid (vinegar) on it to inactivate the nematocysts  Until pain ceases  Use isopropyl alcohol if vinegar not available  Scrape off nematocysts  May then use ice to decrease pain  Evacuate patients with continued symptoms or suspected box jellyfish envenomation
  49. 49. Removal  Wear gloves for protection  Apply shaving cream, baking soda paste  Shave with razor or other sharp edge  Tetanus prophylaxis  Antihistamines  Watch for infection http://www.prweb.com/releases/2011/10/prweb8913589.htm
  50. 50. Echinoderms • Sea urchins, starfish, sea cucumbers • Venoms usually contained in spines • Local effects most common • Systemic effects do occur • Deaths are extremely rare
  51. 51. Echinoderms  Remove visible spines  Immersion in hot water for 30-90 minutes  Local or regional anesthesia if hot water alone is not adequate  X-ray or ultrasound to look for retained fragments – surgery may be needed  Tetanus prophylaxis  Watch for infection
  52. 52. Quiz  A patient presents to your emergency department after being stung by a jellyfish. At the scene life guard treated with wound with urine, shaving cream, vinegar, sea water, and taco sauce. What is the next best treatment?  A. Local wound care and tetanus prophylaxis  B. More urine  C. Vinegar mixed with shaving cream  D. Cold Tap Water
  53. 53. Quiz  A patient presents to your emergency department after being stung by a jellyfish. At the scene life guard treated with wound with urine, shaving cream, vinegar, sea water, and taco sauce. What is the next best treatment?  A. Local wound care and tetanus prophylaxis  B. More urine  C. Vinegar mixed with shaving cream  D. Cold Tap Water
  54. 54. Drowning
  55. 55. The Eve Method August 1946 copy of Popular Science
  56. 56. Szpilman D, Bierens J, Handley A, Orlowski J. Drowning. N Engl J Med. 2012;366(22):2102-10.
  57. 57. Terminology  Drowning: Process resulting in respiratory impairment from submersion / immersion in liquid medium. Victim may live or die during or after process. The outcomes are classified as death, morbidity, and no morbidity.  The Drowning Process: A continuum that begins when the victim’s airway lies below the surface of liquid, usually water, preventing the victim from breathing air.  Drowned: refers to a person who dies from drowning
  58. 58. Drowning  Second only to MVA as most common cause of accidental death in US  Risk factors:  male sex  age <14 years  alcohol use/risky behavior  Low income/Poor education  rural residency  aquatic exposure  lack of supervision.
  59. 59. Drowning Pathophysiology  Most important abnormality of drowning is a profound HYPOXEMIA resulting from asphyxia.  Sequence of cardiac rhythm deterioration is usually tachycardia followed by bradycardia, pulseless electrical activity, then asystole.
  60. 60. Drowning Treatment  Immediate and adequate resuscitation is most important factor influencing survival.  For unconscious: in-water resuscitation may increase favorable outcome by 3 times.  Drowning persons with only respiratory arrest usually respond after rescue breaths. If no response, assume cardiac arrest & start CPR.  Full neurologic recovery is not predicted if victim has been submerged >60 min in icy water or >20 min in cool water.
  61. 61. Predictors of Outcome  Early BLS and ACLS improve outcomes (ABC’s)  Duration of submersion and risk of death/severe neurologic impairment after hospital discharge  0–5 min — 10%  6–10 min — 56%  11–25 min — 88%  >25 min — nearly 100% http://ondrowning.blogspot.com/2013/01/lifeguard- fatigue-and-cpr.html
  62. 62. Diving Medicine
  63. 63. Dysbarism  All the pathologic changes caused by altered environmental pressure  Altitude-related event  Underwater diving accident  Blast injury that produces an overpressure effect
  64. 64. Types  Barotrauma – dysbarism from trapped gases  Decompression sickness – dysbarism from evolved gases  Nitrogen narcosis – dysbarism from abnormal gas concentration (“Rapture of the Deep”)
  65. 65. Pressure is doubled, volume is halved. PV = K Every 33 ft of descent increases the pressure by 1 atm.
  66. 66. Boyle’s Bubbles  Boyle’s law states: pressure of gas is inversely related to its volume.  As pressure increases with descent, the volume of gas bubble decreases, as pressure decreases with ascent, the volume of gas bubble increases.  Air-containing spaces act according to Boyle’s law.  Lungs, middle ear, sinuses and gastrointestinal tract.
  67. 67. Middle Ear Squeeze  Barotitis media-Most common diving-related barotrauma  Equalization of pressure via eustachian tube is unsuccessful  Too rapid descent or infection/inflammation  TM is pulled inward & can rupture  Fullness in ears, severe pain, tinnitus
  68. 68. Middle Ear Squeeze  PE – erythema or retraction of TM, blood behind TM or rupture, bloody nasal discharge  Reverse ear squeeze occurs on ascent  Treatment – prevention: clear ears during dive  If TM not ruptured – pseudoephedrine and oxymetazoline nasal spray  If TM ruptured – antibiotic for 7-10 days  Suspend diving activities
  69. 69. Other Barotrauma  Barotitis externa  Alternobaric vertigo  Barosinusitis  Barodontalgia  Face mask squeeze
  70. 70. Pulmonary Over-Pressurization  A too-rapid ascent  Lung emptying is incomplete  Lung volume expands rapidly  Pneumothorax, pneumomediastinum, SQ emphysema, rupture into pulmonary vein causing air embolism  Simple pneumothorax may progress to tension on further ascent
  71. 71. Arterial Gas Embolism (AGE)  Results from air bubbles entering pulmonary venous circulation from ruptured alveoli  Usually develops right after diver surfaces  Sudden LOC on surfacing should be considered an air embolus until proven otherwise  Cardiac – ischemia, dysrhythmias, cardiac arrest  Neurologic – LOC, confusion, stroke-like sx
  72. 72. AGE Vann, RD.; Butler, FK.; Mitchell, SJ.; Moon, RE. “Decompression illness.” The Lancet, v. 377 issue 9760, 2011, p. 153-64.
  73. 73. Arterial Gas Embolism (AGE)  Recompression in hyperbaric chamber  Transport supine, not in Trendelenburg  100% oxygen, intubate if necessary  IVF  Aspirin for antiplatelet activity if not bleeding  Transport in plane pressurized to sea level or helicopter no higher than 1000 ft. above sea level
  74. 74. Decompression Sickness (DCS)  Henry’s Law – the amount of a gas that will dissolve in a liquid is proportional to partial pressure of gas over the liquid  Nitrogen equilibrates through the alveoli into the blood, but is 5 times more soluble in fat  The longer and deeper the dive, the more nitrogen gas will be accumulated in the body
  75. 75. Decompression Sickness  During a slow ascent, pressure decreases, nitrogen in the tissues is released into blood and alveoli  If ascent is too quick, gas comes out of solution and forms gas bubbles in the blood or tissue  Type I – extravascular gas bubbles  Type II – intravascular nitrogen gas emboli
  76. 76. Type I DCS  “The Bends” – periarticular joint pain is most common symptom of DCS  Shoulders and elbows most often affected  Dull, deep ache, mild at first and becomes more intense  Palpable tenderness  Vague area of numbness around the affected joint
  77. 77. Type I DCS  Cutaneous – pruritus, cutis marmorata, hyperemia, orange peel  Lymphedema  Fatigue, especially if severe Vann, RD.; Butler, FK.; Mitchell, SJ.; Moon, RE. “Decompression illness.” The Lancet, v. 377 issue 9760, 2011, p. 153-64.
  78. 78. Type II DCS  Pulmonary system (The Chokes)  Nervous system (The Staggers)  Decompression shock
  79. 79. Cerebral AGE vs. DCS II  Cerebral AGE  May occur after any type of dive  Onset is immediate (<10- 120 min)  Only brain  DCS II  Dive must be long enough to saturate tissues  Onset is latent (often 2- 6 hrs)  Spinal cord and brain
  80. 80. Pulmonary DCS  “The Chokes”  May begin immediately after dive but often takes up to 12 hours to develop  Triad – shortness of breath, cough, and substernal chest pain or chest tightness  Cyanosis, tachypnea, and tachycardia
  81. 81. Neurologic DCS  Spinal cord is the most common site affected  Lower thoracic and lumbar regions  Low back pain, “heaviness” in legs, paresthesias, possible bladder or anal sphincter dysfunction  Brain – variety of symptoms and difficult to distinguish from AGE  Scotomata, headache, confusion, dysphasia
  82. 82. Decompression Shock  Vasomotor decompression sickness  Rapid shift of fluid from intravascular to extravascular spaces (unknown reason)  Rare but often lethal  Weakness, sweating, hypotension, tachycardia, pallor  Despite fluids, hypotension may not respond until recompression
  83. 83. DCS Diagnostics  History is most important  Lab used to rule out other conditions and/or obtain baseline measurements  CXR  ECG  CT  MRI  Testing should not delay transfer to HBO
  84. 84. DCS Treatment  ABCs  Transport supine, not Trendelenburg  100% oxygen  IVF  Recompression therapy  Divers Alert Network (DAN): 919-684-8111  75-85% have good results when recognition and treatment are prompt
  85. 85. Quiz  You are on a plane from Key West to Cleveland when the passenger next to you starts to arch his back and bend his knees. He then starts to rapidly breath and call for the flight attendant. She asks, “is there a doctor on the plane?” What do you do?  A. Lecture the passenger on diving too close to a flight  B. Start high flow O2, keep the patient supine, and get the patient to a hyperbaric chamber upon landing  C. Intubate and hyperventilate
  86. 86. Quiz  You are on a plane from Key West to Cleveland when the passenger next to you starts to arch his back and bend his knees. He then starts to rapidly breath and call for the flight attendant. She asks, “is there a doctor on the plane?” What do you do?  A. Lecture the passenger on diving too close to a flight  B. Start high flow O2, keep the patient supine, and get the patient to a hyperbaric chamber upon landing  C. Intubate and hyperventilate
  87. 87. High Altitude Medicine
  88. 88. High Altitude Illness  Rate of ascent  Altitude reached  Sleeping altitude  Individual physiology
  89. 89. High Altitude Illness  Rate of ascent: Graded ascent is safest method to facilitate acclimatization and prevent sickness.  Altitude reached: AMS usually seen at altitudes in > 2000 meters (6560 ft) and caused by hypobaric hypoxia.  Sleeping altitude: Increases >600 meters in sleeping altitude should be avoided.  Individual physiology: Age, gender, and fitness level do NOT play a role in susceptibility to altitude illness.
  90. 90. Risk Factors  History of high altitude illness  Residence at altitude below 900 m  Exertion  Preexisting cardiopulmonary conditions  Age < 50 years  Physical fitness is not protective
  91. 91. High Altitude Medicine  Acute Mountain Sickness (AMS)  High Altitude Cerebral Edema (HACE)  High Altitude Pulmonary Edema (HAPE)
  92. 92. Acute Mountain Sickness  History is key (total elevation gain and rate of gain)  AMS is present if one is at altitude and, if in addition to headache, at least one of the following symptoms is present:  Dizziness or lightheadedness  Fatigue or weakness  Nausea/vomiting/anorexia  Insomnia
  93. 93. AMS  Hypoxia  Neurohumeral and hemodynamic responses  Overperfusion of microvascular beds  Elevated hydrostatic capillary pressure  Capillary leakage  Consequent edema
  94. 94. AMS  Avoid further ascent until symptoms have resolved  Descend if no improvement in 24 hours or worsening symptoms  Non-narcotic pain relievers for headache  Supplementary oxygen  Acetazolamide, dexamethasone  Gamow bag
  95. 95. Acetazolamide  For both treatment and prevention of AMS  Mechanism of action: increase urinary excretion of sodium, potassium and bicarbonate resulting in a hyperchloremic metabolic acidosis, which stimulates ventilation, improving arterial oxygen saturation  Decreases periodic breathing and improves sleeping
  96. 96. Acetazolamide  Speeds up acclimatization  250 mg po bid for treatment  125-250 mg po bid starting 24 hr before ascent and the first 2 days at high altitude
  97. 97. Dexamethasone  For treatment or prevention of AMS  Does NOT speed up acclimatization  May improve integrity of blood-brain barrier, thereby reducing edema  4 mg po every 6 hrs for treatment  4 mg po every 12 hrs for prevention
  98. 98. http://www.jyi.org/issue/on-the-mountains-high-altitude-sickness-in-nepal/
  99. 99. High Altitude Cerebral Edema (HACE)  HACE: progression of AMS to life-threatening end-organ damage.  Defined as severe AMS symptoms with additional obvious neurologic dysfunction:  Ataxia  Altered level of consciousness  Severe lassitude  HACE almost never occurs without antecedent AMS symptoms as a harbinger.  The progression of AMS to coma typically occurs over 1 – 3 days.
  100. 100. HACE  Progression of AMS  Ataxia is the single most useful sign  Diffuse neurologic dysfunction  Altered mental status, nausea, vomiting, seizures, decreased LOC, coma and finally death  Once coma present – 60% mortality rate  Cause of death – brain herniation
  101. 101. http://www.altitudemedicine.org/index.php/altitude-medicine/learn-about-altitude-sickness/what-is-hace
  102. 102. HACE Treatment  Descend  Descend !  Descend !!  Oxygen  Dexamethasone 8 mg load followed by 4 mg every 6 hrs  Gamow bag if descent not possible
  103. 103. HAPE  Accounts for most deaths from high altitude illness  Non-cardiogenic pulmonary edema  Commonly strikes the second night at a new altitude  Rarely occurs after more than four days
  104. 104. HAPE  Early diagnosis is crucial to recovery  Decreased exercise performance  Dry cough initially  Tachycardia and tachypnea at rest  Dyspnea at rest  Rales typically originate in right axilla and become bilateral as illness progresses  Cerebral signs and symptoms are common
  105. 105. HAPE Patient admitted with progressive respiratory distress 24 hours after arriving at town at 2700 meters above sea level. http://radiopaedia.org/images/1564322
  106. 106. HAPE  Pulmonary hypertension due to hypoxic pulmonary vasoconstriction  Elevated capillary pressure  Stress failure of pulmonary capillaries as a result of high microvascular pressure is the presumed final process leading to extravasation of plasma and cells  Impaired clearance of fluid from alveolar space probably has a role
  107. 107. HAPE Treatment  Descent is treatment of choice  Exertion may worsen the illness  Oxygen  Gamow bag if unable to descend  Nifedipine 10 mg po initially, then 20-30 mg extended release every 12 hrs – decreases pulmonary artery pressure  Inhaled beta-agonists
  108. 108. http://www.jyi.org/issue/on-the-mountains-high-altitude-sickness-in-nepal/
  109. 109. Quiz  You decide to climb to the top of Mt. Everest. While nearing the top, your partner begins to have a seizure and becomes unresponsive. What is the best treatment for him?  A. Prednisone taper  B. Acetazolamide IV  C. High Flow Oxygen  D. Descent
  110. 110. Quiz  You decide to climb to the top of Mt. Everest. While nearing the top, your partner begins to have a seizure and becomes unresponsive. What is the best treatment for him?  A. Prednisone taper  B. Acetazolamide IV  C. High Flow Oxygen  D. Descent
  111. 111. Questions?

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