Altitude Flashcards

1
Q

How does the body adapt to hypoxic environments?

A
  • Through hyperventilation
  • The increased production of RBC
  • Increased capacity of the lungs to diffuse
  • Increase vascularity of tissue
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2
Q

What are the three types of altitude sickness?

A
  • Acute Mountain sickens (AMS)
  • High-Altitude cerebral Oedema (HACE)
  • High-Altitude pulmonary Oedema (HAPE)
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3
Q

Signs and symptoms of early/mild Acute Mountain Sickness?

A
  • Feeling of hangover
  • Headache
  • Nausea and vomiting
  • Weakness
  • Normally self-limiting
  • Insomnia
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4
Q

Signs and symptoms of late/severe Acute Mountain Sickness?

A
  • Dyspnoea
  • Vomiting
  • ACS
  • Headache
  • Ataxia
  • Retinal Haemorrhage
  • May progress to HACE or HAPE
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5
Q

Acute mountain sickness, how does it affect the body?

A
  • Acute mountain sickness is caused due to the rate and height of ascent. It is not related to fitness or gender.
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6
Q

Explain the pathophysiology of High Altitude Cerebral Oedema.

A
  • As there is an increase in ICP this causes decreased CPP that results in death
  • This is due to vasogenic oedema
  • And as hypoxia sets in it results in an increase in extracellular fluid + micro vascular permeability.
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7
Q

What are the signs and symptoms of High Altitude Cerebral Oedema?

A
  • Progressive decline in mental status
  • Truncal ataxia
  • Cranial nerve palsies
  • SOB
  • Fatigue
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8
Q

What are the treatments for high altitude cerebral oedema?

A
  • Stop the climb, and then proceed with a rapid controlled descent.
  • Dexamethasone to decrease capillary permeability and decrease ICP
  • Oxygen 2-4L/min and then hyperbaric treatment
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9
Q

What is the cause of non-cardiogenic pulmonary oedema?

A
  • A rise in pulmonary artery pressure
  • There is an increase in arterial pressure this result in hydrostatic overcoming oncotic pressure that causes a fluid shift into the interstitial space.
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10
Q

Who is more susceptible to high altitude pulmonary oedema?

A
  • Those with underlying respiratory or cardiac pathologies.
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11
Q

What are early signs of high altitude pulmonary oedema?

A
  • Fluid in interstitial space

- Dry cough and decreased exercise tolerance

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12
Q

What are late signs of high altitude pulmonary oedema?

A
  • Tachycardia
  • Increasing dyspnoea
  • Marked weakness
  • Productive cough and frothy sputum and cyanosis
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13
Q

What is the primary cause of barotrauma?

A
  • Develops due to breathing gases at higher than normal atmospheric pressure
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14
Q

For every ten meters below sea level?

A
  • It drops 1 ATA
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15
Q

List the forms of trauma caused by Pulmonary Barotrauma?

A
  • Pneumothorax caused by rapid ascent, breathe holding or breathing compressed air.
  • Alveolar rupture can allow air into the pulmonary circulation, causing arterial gas embolism.
  • May cause lung tissue damage and emphysema
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16
Q

What are signs and symptoms of Pulmonary Barotrauma?

A
  • Chest pain
  • Difficulty breathing
  • Coughing
  • Blueness of lips and tongue (cyanosis)
  • Voice change
  • Difficulty swallowing
  • Crackly skin around neck
  • Reduced responsiveness
  • Signs/symptoms of decompression illness may also present
17
Q

Signs and symptoms of nitrogen narcosis?

A
  • Light headedness
  • Inattention
  • Difficulty concentrating
  • Poor judgment
  • Anxiety
  • Decreased coordination
  • Hallucinations
  • Coma, may lead to death
18
Q

How does decompression illness occur?

A
  • Ambient pressure increases as divers descend; this increases the partial pressure of nitrogen which is dissolved into body fluids.
19
Q

How does a slow ascent result in off gassing?

A
  • A slow ascent will decrease the ambient pressure
  • Decrease the partial pressure of nitrogen
  • The above results in tissue super-saturation which is overcome by excess moving to the lungs and being eliminated. This is off gassing.
20
Q

What does a Fast Ascent cause?

A
  • Nitrogen bubbles will form in the venous, arterial, lymphatic system or in the tissues themselves.
21
Q

List signs and symptoms of decompression illness?

A
  • Musculoskeletal pain
  • Itching
  • Respiratory complaint
  • Neurological changes
22
Q

What is the primary goal in the treatment of the patient with Decompression Illness?

A
  • To allow nitrogen to off-gas, increasing 02 delivery and allowing the lungs to rehydrate
23
Q

What position must patients with DCI be kept in and why?

A
  • In the supine or lateral position at all times to prevent nitrogen bubbles from moving upwards.
24
Q

What amount of fluids should be administered to the DCI patient regardless of perfusion status?

A
  • 1L over 15 – 20 min to rehydrate patient, unless chest is unclear.
  • We are aiming to rehydrate the patient due to the potential fluid shift DCI can cause.
25
Why is the aim to keep a patient
- Because higher than this has the potential to undissolved already dissolved nitrogen bubbles.
26
If opioid analgesia is indicated why must you consult before giving?
- Opioids may mask symptoms of DCI and may interfere with the potential for recompression.
27
What are some specific diving Hx that are important?
- Number of dives preformed - Surface interval between dives - Type of ascent - Depth of dive - Breathing gas mixes used - Level of exertion before and after dive
28
What are some good indicators for a positive outcome of a drowning victim?
- Less than five minutes submersion - Higher GCS post-drowning - Initiation of good quality CPR within 10 minutes - First spontaneous breath within 30 minutes
29
What are the primary causes of morbidity and death from drowning?
- Hypoxaemia and acidosis that result in cardiac arrhythmia and brain death.
30
What are some other determinates that impact the ultimate outcome of a drowning victim?
- The type of fluid drowned in - The temperature of the water - Use of drugs and alcohol - Mammalian diving reflex – overrides the homeostatic reflexes - Medical complications /history - General factors
31
What is the difference between a salt water and Freshwater drowning?
- Fresh water is a hypotonic solution and dilutes the surfactant causing alveolar collapse - Salt water is a hypertonic solution that pulls fluid into the alveoli causing pulmonary oedema - Both of these lead to an intrapulmonary shunt and a V/Q mismatch - This then leads to hypoxia
32
If positive outcomes are seen in the drowning Pt what outcomes may they see later on?
- Respiratory infections - Acute respiratory distress syndrome - Pneumonia
33
What injuries may affect the CNS that can determine Pt outcome and ongoing morbidity?
- Tissue hypoxia - Ischemia - Raised ICP - Cerebral oedema - Neuron cell damage
34
What primary affects are seen on the myocardial system in the submersion patient and what are their causes?
- Myocardial dysfunction and arrhythmia secondary to hypothermia, hypoxemia, acidosis and electrolyte imbalance. - More likely to see sinus brady, PEA and AF then VF or asytole.
35
What factors may suggest a pt has aspirated?
- Porloged immersion time - Any LOC - Manual ventilations - Cough - CPR required - GCS <5 - Cyanosis - Tachycardia - Wheeze/crackles on auscultation - Pink, frothy sputum - Altered conscious state - Decreased Sp02 readings
36
How is mammalian diving reflex caused? And what is its aim?
- It is caused by cooling the forehead | - And is aimed at optimising respiration when submerged.
37
What are the resulting signs and symptoms of Mammalian diving reflex?
- Bradycardia - Peripheral vasoconstriction - Bradypnoea - Movement of blood to the core, this helps maintain higher core temperatures longer and initiates a bolus of oxygenated blood to vital organs prior to cardiac arrest
38
What is immersion syndrome and what is believed to be the cause?
- Sudden cardiac arrest following cold water immersion. | - Caused by a vagal response coupled with vasoconstriction
39
What is recovery syncope?
- It may occur following the removal from cold water. | - The loss of external water pressure leading to reduced central perfusion.