Week 10- Environmental Emergencies Flashcards
Who does drowning most likely impact?
- Youth <5 yrs of age
- Males w drug or alcohol intoxication
- Disorders that cause LOC
Drowning is the process of what?
The process of experiencing respiratory impairment from submersion or immersion in a liquid
Submersion
The act of being completely covered by a liquid
Immersion
Being partly covered by a liquid
What is the patho of drowning?
- Starts with breath holding, most victims lose consciousness within 2 mins
- Occurs due to hypercapnia overriding the voluntary urge to hold breath (55mmHg CO2)
- Prior to LOC, gasping, coughing can occur causing swallowing large amounts of water
- Once water enters the pharynx and/or trachea the pt will suffer from laryngospasm, can be permanent or temporary
- If the spasm is permanent there will be no aspiration (dry drowning)
- When temporary, fluid begins to enter the lungs further compounding hypercapnia & hypoxia causing cardiac arrest
- Brain damage occurs between 4-6 mins after LOC
- Progression is normally tachy, brady, PEA, & asystole
Aspiration of fluid can lead to,
- Decrease compliance, and
- Pt’s can present with non-cardiogenic pulmonary edema (due to fluid overload) on initial presentation
- With ARDS in later stages due to surfacant washout
What does cold water drowning trigger?
- Triggers the mammalian diving reflex causing bradycardia, peripheral vasoconstriction, & reduced O2 demand
What is dry drowning/ secondary drowning?
- Described as laryngospasm stating that no water ever made it to the lungs
- Can be immediate or delayed
- Gets worse within time, can lead to infection
Smalls amount of aspirated water can be…
- Reabsorbed in vasculature or
- Can cause decrease in lung compliance
- Loss of surfacant
- Atelectasis and
- Hypoxia
Acute Respiratory Distress Syndrome
- Cascade of processes impacting avelio/ capillaries causing increase capillary permeability, leading to non-cardiogenic pulmonary edema (from loss of protein)
- The transitions to atelectasis, decreased lung capacity, ventilation/ perfusion mismatch (if only one lung is impacted it will not be ventilated but still perfused) and hypoxia
What is the drowning management?
- Need to know the duration of submersion
- Condition of water
- Cold water
- Manage A, B, C’s
- Treat as general cardiac arrest (unless hypothermic)
What is boyle’s law?
- At constant temp, volume of gas is inversely proportional to its pressure
- Pulling up increases volume and decreases pressure
- Pushing down decreases volume and increases pressure
What is Dalton’s law?
- The total pressure of a mixture of gases is the sum of the partial pressures of each gas
What is henry’s law?
- At constant temp, the amount of gas dissolved in a liquid is proportional to the partial pressure of gas above the liquid
What is barotrauma?
- When on decent it is sometimes referred to as the “squeeze” and on ascent a “reverse squeeze”. This all occurs bc of Boyle’s Law
- If there is a blockage in ear for instance this can lead to barotrauma
What can barotrauma cause?
- Tympanic membrane rupture
- Tinnitus
- Vertigo
- Nausea, vomiting
Pulmonary Overpressurization Syndrome (Pops) and Air Embolism
- When a diver makes his ascent there can be air trapped within the lungs from:
- breath holding
- bronchospasm
- mucus plugs
- Can cause alveolar rupture
What will the pt present with pulmonary overpressurization syndrome and air embolism?
- Dyspnea
- Pleuritic pai
- SubQ emphysema
- Pneumo
Decompression Sickness
- It occurs when nitrogen that is compressed in tissues/ blood from increase pressure when diving turns back into gas bubbles when surfacing (henry’s law) bc it can’t be exhaled fast enough
- Surfacing too quickly
What can decompression sickness cause?
- Due to poor tissue perfusion
- It can cause joint pain and also affect the spinal cord.
- Can be minor or cause embolism or CVA type symptoms
Treatment for decompression sickness?
- High flow O2
- Tranport to hyperbaric chambers if possible
What is nitrogen narcosis?
- Due to increased pressures, normally with deeper dive (75-100 ft) nitrogen becomes dissolved in blood and passes the blood brain barrier
What is the affect of nitrogen?
- Nitrogen acts similar to alcohol cause the diver to make poor decisions during the dive
- This can cause injury or death if impairment is enough to remove respirator
What is the prehospital treatment for diving injuries?
- High flow O2 as per BLS
- Left lateral position