Environment

Question 1

Drowning assessment

Answer 1

Immersion/submersion
Time in, time removed, temp, type
Precipitating event
Other injuries
Airway
Oxygenation/ventilation
Cardiac rhythm
Temp
Electrolytes

Conn and Modell 2 hours post
A-awake
B-conscious but obtunded
C-comatose 1-flexion to pain, 2-extension to pain, 3-flaccid

Question 2

Drowning treatment

Answer 2

Support abc, reward, prevent secondary brain injury

Awake - supportive, 6 hours observation at least, if o2 required needs longer/admit

O2, CPAP, intubation, salbutamol if spasm
IVF (care re oedema)
Rewarm
Abx if gross contamination/pool kids

Question 3

Drowning prognosis

Answer 3

Submersion <6 mins 85% good outcome, > 10 mins poor

GCS < 5 poor but good if improving first 2-6 hours

First breath <15-30 mins < 10% poor
First breath > 60-120 50-80% poor

Orlowski scale (<3 90% recovery, >3 5% recovery)
Age < 3
Submersion > 5 mins
No resus attempt first 10 mins
Coma on arrival to ED
pH < 7.1

Question 4

When to stop CPR in drowning

Answer 4

Blood frozen
K > 11
Asystole after 1 hour CPR (warmed)
Water temp > 6 and immersion for > 30 mins
Water temp < 6 and immersion for > 90 mins
Submersion > 10 mins without hypothermia

Question 5

What are the risk factors that influence developing altitude sickness

Answer 5

Rate of ascent
- moderate >2800m and high >3500m in 1 day
- If previous AMS, mod>2500m and high risk >2800m

Sleeping elevation (moderate >500m/day and high >1000m/day above 3000m)

History of acute mountain sickness (high risk if previous HAPE/HACE)

Maximum height achieved
Strenuous exertion at altitude
Lack of previous acclimation (<5days above 3000m in the last 2 months)

Pt specific contraindications
- sickle cell disease
- Coagulopathys as blood viscosity increased in high altitude
- Pregnancy

Question 6

How do you prevent altitude illness

Answer 6

Acclimatization before exposure (several days above 2000m prior to ascending)
2 or more days to ascend initial 3000m
Sleeping elevation increases <500m/day (above 3000m)
Extra rest day for every 1000m of ascent

Question 7

What are the prophylactic medications for altitude sickness and who are they recommended for?

Answer 7

Sensible ascent profile is best
Moderate or high-risk groups

AMS and HACE prophylaxis
- Acetazolamide 125mg BD start 1 day prior
- Dex 4mg BD starting on the day of is second line for pts allergic or intolerant of acetazolamide (preexisting severe reaction to sulfanomides)

HAPE
- Nifedipine SR 30mg BD the day prior
- Dex 8mg BD
- Phosphodieserase 5 inhibitors (tadalafil 10mg BD)

All should be continue until acclimatization (2-3 days, 4 days for HAPE) after reaching target altitude or when commencing descent

Question 8

What is acute mountain sickness and how is it manged

Answer 8

Cerebral odema usually occuring >2500m.
>4500m affects 50-85% of unacclimatised people and progresses to life threatening HACE in 1-2%

CLINICAL FEATURES
Headache (within 12hrs)
+ fatigue/weakness or anorexia/nausea/vomiting or dizziness/lightheadedness

MANAGEMENT
If mild symptoms needs to stop, rest, rehydrate and acclimatize. If not improving after 1-2 nights of rest may need to descend.

• Descent
  If serious needs urgent descent of at least 300m until symptoms improve (may be 1000m)
• May need O2 by does not reverse symptoms
• Portable Gamow pressure bag if available (hyperbaric therapy)
• Dex 8mg stat and then 4mg q6hr
  + Acetazolamide 250mg BD if not already used

Question 9

What is the difference between High altitude cerebral oedema (HACE) and acute mountain sickness (AMS)

Answer 9

• Drowsiness, stupor, ataxia or confusion indicate HACE as opposed to AMS which is normal physiological response to hypoxia. HACE also has truncal ataxia and possible fever
• HACE typically develops over 1-3 days after ascending 3000-4000m while AMS develops over 12hrs after ascending 2500m
• HACE more lethal with rapid progression to brainstem herniation and death within 24hrs if not managed
• HACE MRI shows vasogenic oedema and microhemorrhages that are located predominately in corpus callosum

Question 10

How is HACE managed

Answer 10

Same as AMS

Descent lowest possible altitude >300m ASAP
O2 or Portable Gamow pressure bag (hyperbaric therapy)
Dex 8mg stat and 4mg q6hr + Acetazolamide 250mg BD if not already on

Question 11

What is High altitude pulmonary oedema (HAPE) and how is it managed

Answer 11

Noncardiogenic pulmonary oedema due to exaggerated hypoxic pulmonary vasoconstriction, high pulmonary artery pressures and alveolar capillary leakage

Symptoms progress over 2-4days at new altitude

At least 2 symptoms:
Dyspnoea at rest
Cough
Weakness or decreased exercise tolerance
Chest tightness or congestion

+
At least 2 signs:
Crackles or wheeze
Central cyanosis
Tachypnoea
Tachycardia

Advanced HAPE are worsening cough and dyspnea, orthopnea and frothy (possibly blood stained) sputum

Mortality is 50% if untreated

MANAGEMENT
O2, aim sats >90%.
Portable Gamow pressure bag (hyperbaric therapy) if available as temporizing measure until descent
Descent >1000m
Nifedipine 10mg SL stat + 30mg SR BD
Loop diuretics best avoided as pts already intravascularly deplete