Physiology

Question 1

What is the normal core temp?

Answer 1

37 degrees celsius

Question 2

Name the two systems of the circulatory system

Answer 2

Systemic and Pulmonary

Question 3

hypertension

Answer 3

high blood pressure; obesity, stress, & age are risk factors; causes long-term effects

Question 4

hypotension

Answer 4

low blood pressure; typical signs are fainting and dizziness

Question 5

Diving reflex

Answer 5

bradycardia (heart rate reduces by 20%); peripheral vasoconstriction (decrease in blood flow to the extremities); blood shift (the shifting of blood plasma to the thoracic cavity)

Question 6

Shallow water blackout

Answer 6

a diver hyperventilates themselves removing CO2 from their lungs consequently removing the natural trigger to breath from their bodies. Even though the body needs oxygen the body lacks the response to begin breathing.

Question 7

Oxygen Poisoning

Answer 7

caused by breathing oxygen at elevated partial pressure (1.6bar pp; 6m; 70 with air)
Symptoms dizziness, nausea, visual disturbance, facial twitching, concentration disorder acoustic hallucination, convulsions & death
Treatment - patient needs fresh air

Question 8

Hypoxia

Answer 8

oxygen deficiency caused by equipment problems, blockage of the respiratory passage, pneumothroax, hyperventilation
Symptoms - lack of muscle control, drowsiness, weakness, agitation, loss of consciousness
Treatment - 100% O2, symptoms similar to AGE treat for AGE is unsure

Question 9

Nitrogen narcosis

Answer 9

caused by increased partial pressure of nitrogen (usually above PPN2 3.5bar)
Symptoms - laughter, mild euphoria; dizziness; response dizziness
Treatment - ascend, if mentally acuity doesn’t return abort dive

Question 10

Hypercapnia

Answer 10

high level of carbon dioxide
Symptoms - breathing rapid & shallow; unconsciousness; similar to hypoxia (rule out before treating for hypercapnia)
Treatment - flush helmet or mask, exchange faulty equipment, fresh air - recovery should occur within 15 minutes

Question 11

Carbon Monoxide poisoning

Answer 11

carbon monoxide displaces expygen from haemoglobin and interferes with cellular metabolism
cause by exhaust fumes entering compressor or breakdown of lubricating oil in compressor
Symptoms - similar to hypoxia; nausea, cherry red coloring (skin), unconsciousness, breathing stops
Treatment - resuscitation, 100% O2

Question 12

Bartotrauma

Answer 12

pressure injury caused by differential pressures between body air cavities and external environment

Question 13

Aural Barotrauma

Answer 13

Outer ear squeeze - caused by hood or wax buildup

Middle ear squeeze - damage between eardrum & eustachian tube

Question 14

Parts of the ear

Answer 14

outer (Pinna, External auditory canal); Middle ear (ear drum, ossicles, eustachian tube); inner ear (oval window, cochlea, semi-circular canals)

Question 15

Middle ear barotrauma of ascent

Answer 15

aka reverse block

blockage in eustachian tube

Question 16

Dental Barotrauma

Answer 16

tooth cavity squeeze (tooth implosion on descent and blown out fillings on ascent)

Question 17

Pulmonary Barotrauma

Answer 17

thoracic squeeze

Lung edmema

Question 18

thoracic squeeze

Answer 18

injury to lung due to air spaces not equalizing to ambient pressure
symptoms - chest pain, bleeding, coughing of foamy blood, problems breathing

Question 19

Lung edmema

Answer 19

accumulation of fluid in the lungs
Symptoms - chest pain, bleeding, coughing of foamy blood, breathing problems, paleness
Treatment - place patient in sitting position, administer O2

Question 20

Decompression pulmonary barotrauma

Answer 20

syndrome which results in gas leaving its natural confines and entering wither the interstitial space within the lung, the pleural cavity or the blood stream
Main cause rupture of pulmonary tissue through an over expansion of the lungs during ascent
Lead to - AGE; Mediastinal Emphysema; Subcutaneous Emphysema; Pneumothorax, Tension Pneumothorax

Question 21

Arterial Gas Embolism (AGE)

Answer 21

Gas from a ruptured lung enters the pulmonary circulation and migrates to the let side of the heart. Gas bubbles are then pumped into arteries and blockage occurs.
Symptoms - unconsciousness; numbness, weakness, paralysis
Treatment - decompression chamber, 100% O2

Question 22

Mediastinal Emphysema

Answer 22

gas from ruptured lung escapes into the interstitial tissue space and from there into the mediastinum (space btwn lungs which contains heart), vessels and arteries
Symptoms - chest pain, change of voice, difficulties breathing
Treatment - 100% O2

Question 23

Subcutaneous Emphysema

Answer 23

can develop from mediastinal emphysema; air collects in the subcutaneous tissues of the neck and head
Symptoms - skin swelling and crepitation
Treatment - 100% O2

Question 24

Pneumothorax

Answer 24

alveolar gas escapes into the pleural space
a one time leakage
Symptoms - sharp chest pain, shortness of breath, blueing of lips and finger nail beds (cyanosis)

Question 25

Tension pneumothorax

Answer 25

a continuous leakage of gas into the pleural space with every breath
can lead to a collapsed lung
heart and other lung are pushed to other side of thoracic cavity
Symptoms - in addition to those of pneumothorax, reduced movement of chest wall, tracheal shift

Question 26

Sinus squeeze and sinus barotrauma of ascent

Answer 26

inability to equalize in pressure
caused by blockage
Symptoms - pain above eyes, cheeks and side of head, nasal bleeding

Question 27

Other Barotraumas

Answer 27

Nips - skin trapped in folds of drysuit
Facial squeeze - mask pressure doesn’t equalize
stomach/bowel barotrauma - discomfort due to trapped gas

Question 28

Decompression Illness (DCI)

Answer 28

The rate of decompression is too high, the bubble burden will exceed the lung capacity to clear bubbles. In this case bubbles will transit the lungs and enter arterial circulation.
Symptoms - 50% of divers develop symptoms mins after dive; after 3hr 90% of divers show symptoms/ limb pains occur 6hr w/in 90%

Question 29

DCI risk factors

Answer 29

obesity, menstruation, hard physical labor during or after dive, cold water, flying after diving, too fast ascents, yo-yo diving

Question 30

DCI symptoms

Answer 30

Cutaneous manifestation (skin bends) - formation of small bubbles in germinating layer of skin - itching and rash in affected area
Lymphatic manifestation - bubbles in lymphatic capillaries - enlarged lymph nodes, orange skin
Limb pains - probably formation of small bubbles in nerve ends
Neurological - cause unclear; symptoms dependent on part of brain affected
Audio-vestibular manifestation - formation of gas bubbles in balance organ - upset in balance and hearing, vertigo & nausea, flicking of eyes
Pulmonary manifestation (chokes)

Question 31

DCI treatment table

Answer 31

all DCS gas embolism patients should initially be recompressed to 18m and start breathing oxygen
Treatment table 6

Question 32

Hypothermia

Answer 32

temp falls below 35 degrees celsius
body loses heat through: evaporation, radiation, conduction, convection
Below 33 degrees condition becomes serious
Naked person could only survive 5-30min in 5degree water

Question 33

Hyperthermia

Answer 33

body rises above 39 degrees celsius

caused by high outside temp

Question 34

Drowning

Answer 34

death by suffocation - primary cause of death hypoxia

Question 35

Near drowning

Answer 35

survival of drowning (w/ unconsciousness/ inhalation of water)
can lead to complication, even death

Question 36

Secondary drowning

Answer 36

death caused by chemical and biological changes in the lungs after a near drowning incident

Question 37

Wet drowning

Answer 37

primary cause of death oxygen deprivation (hypoxia)

Question 38

dry drowning

Answer 38

rare (10-15%)\

can lead to death through hypoxia

Question 39

Secondary drowning

Answer 39

occurs after a near drowning incident
can occur up to 72hrs
caused by water damage to inside of lungs and alveoli