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Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL ONE
TUTORIAL 1 : TRIGGER 1
PRESENTATION
It is 10.30 pm on a Friday night, when two medical students see the car ahead of
them run off the road and crash into a tree. They stop and run to the scene. A
young male, covered in blood, is struggling to get out of the driver's seat of his
wrecked car. There is blood spurting from a wound in his left thigh.
"What should we do?"
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL ONE
TUTORIAL 1: TRIGGER 2
FIRST AID & INITIAL EXAMINATION
The students have moved the driver, Mark B., away from the wrecked car. He is
bleeding profusely from the wound in his left thigh. One of the students manages
to control the bleeding by pressing on the open wound with his hands.
Throughout, Mark is conscious and complains of feeling thirsty and cold.
An ambulance and the police arrive soon after. On examination, he is conscious
but confused, groaning in pain and complaining of difficulty breathing. Other
observations are:
- systolic BP 70 mmHg (diastolic too low to measure)
- Pulse 135/min, thready
- respiratory rate 30/minute
- airway intact
- chest extensively bruised and tender
- deformity of the left thigh with substantial bleeding
- numerous bruises and lacerations of both lower limbs
- extreme pallor - pale face, conjunctiva and palmar creases - and cold, sweaty
extremities
- no obvious head injury, no neck pain, pupils equal and reactive to light.
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL ONE
TUTORIAL 1: TRIGGER 3
INITIAL TREATMENT
The ambulance officers provide oxygen therapy and begin an intravenous
infusion. One of them says “This is the fourth accident we’ve been called out to
this week.” They set off on the twenty minute journey to the nearest country
hospital.
One of the medical students accompanies the patient in the ambulance. "What is
the best IV fluid to start with? Is he going to bleed more if we give him a lot of
fluid?" asks the student.
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL TWO
TUTORIAL 2 : TRIGGER 1
EMERGENCY DEPARTMENT
History &Assessment
Mark’s brother, Paul, arrives at the hospital shortly after Mark is brought into
A&E. Paul states that Mark is 19 years old. He usually works as a barman but is
currently unemployed. He smokes 30 cigarettes a day. He is a binge drinker,
taking as much as 200 grams of alcohol (20 standard drinks) in a single sitting,
once or twice weekly. Mark’s father also has a history of heavy alcohol
consumption.
On assessment in Emergency, Mark is found to have a compound fracture of the
left femur with partial laceration of the left femoral artery. His blood alcohol level
is 0.18 g/dl. He has no significant past medical history and subsequently proves
negative for HIV, hepatitis B and C.
Y1W1&2_ Blood on the Road
What we know
Trigger 1 (above)
 Admitted to ED (Paul’s
brother arrived)
 Mark, 19
 Worked as barman, now
unemployed
 Smokes 30 cigarettes
 Binge drinker (200 g/20
standard drinks per session,
once or twice a week)
 Father has history of heavy
alcohol consumption
 On assessment in Emergency
– compound fracture of left
femur, partial laceration of
left femoral artery
Needs to go to the OR
 BAL 0.18 g/dl
Normal alcohol level 0.05
Can’t anaesthetise
(alcohol CNS depressant)
 No significant past medical
history
 Negative for HIV, Hepatitis B
&C
Trigger 2
 Vital signs not improving
 Haemopneumothorax seen
on erect CXR
What we need to know
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Trigger 3
 Open chest surgery – repair
lac to left main bronchus & a
TRIGGERS

MED 1000
Hypotheses
How BAL relates to risk of having MVA
(RTA – Driver Qualification Test)
http://www.rta.nsw.gov.au/licens
ing/downloads/driver_qualificatio
n_handbook.pdf
exponential relationship between
relative crash risk & BAC
Age & sex related risks to having MVA
In above website
Does he abuse other illicit drugs?
Is alcohol hypo/hyper/isotonic
The effect of alcohol on the body
E.g. immune system (chemotaxis),
cardiovascular system, etc
Can we control bleeding & wait?
At what BAL can we do Sx (surgery)?
Should we give antibiotics or tetanus
immunisation?
Alcohol impairs immune system
Chest X-ray (CXR)
GCS score
Abdominal assessment
What is a haemopneumothorax?
Different opacities in CXR
Darkest thing is air (black – lungs
are nearly black)
Grey (darker grey is fatty tissues,
lighter grey is muscles)
Calcified tissues or bones
Very white – metal objects
CXR
Right side of patient is your left
side
Normal – lungs, should be able to
count 9 ribs (taken with full
inhalation)
Pt – darker due to compressed air
Emphysema – lungs will be darker
(air trapped in the lungs, blood/air
contact surface area destroyed,
i.e. alveoli)
Gastric bubble – normal on left
side, always abnormal on right
side (liver)
Could patient have a different type of
shock? (e.g. septic shock)
Septic shock (infection) – does he

Ribs have
punctured the
lung

Septic shock
How it
happens?
Y1W1&2_ Blood on the Road
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pulmonary vein
Large intravenous fluid
replacement (plasma
expander, blood), not
stabilised before surgery
(accumulating blood & air in
pleural space, ongoing blood
loss)
Profound hypotension in
surgery (fluid replacement
unable to keep up with
losses)
Surgery also included
stabilization of fractures
Anaethetist says – not
keeping ahead of this guy’s
losses
Pulse 120
Systolic BP (SBP) 90
Peripheral perfusion is
poor
Have we missed something?
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TRIGGERS
have a fever?
Compensatory mechanisms in shock
Detected by baroreceptors
Renin-angiotensin-aldosterone
cycle
Not working!
From a certain level onwards,
compensatory mechanisms can
damage the body
Mechanisms of shock
How do we assess adequacy of fluid
replacement?
Vital signs – HR, resp rate, skin
colour
Urine output –
normal/increased/decreased?
Prophylactic (preventative)
antibiotics?
Generally not used, unless there
are specific requirements (e.g.
orthopaedic surgery – high risk of
infection)
Not used if surgery is completely
clean/sterile
Prophylactic antibiotics will
increase antibiotic resistance
Losing fluid – from where?
Check urine for blood?
Bleeding from abdomen?
Pt doesn’t have clinical signs
Oedema?
What is affecting blood pressure?
Is it affecting contractility of the
heart
Cardiogenic shock
Preload & afterload
Is the preload affected or not?
Afterload is probably not enough
(BP low, pulse high)
Look at pressure inside veins – JVP
JVP high – cardiogenic shock
MED 1000

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What is it?
More third
spacing?
Blood not
returning to
heart –
blockage?
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL TWO
TUTORIAL 2 : TRIGGER 2
EMERGENCY (cont’d)
Investigations
Despite extensive fluid replacement, Mark’s vital signs are not improving. A chest
X-ray taken in the supine position is hard to interpret. He is propped up and
another film taken in the erect posture.
X-ray shows a haemopneumothorax
Y1W1&2_ Blood on the Road
(see below for a normal chest x-ray for comparison)
TRIGGERS
MED 1000
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL TWO
TUTORIAL 2 : TRIGGER 3
SURGERY
Mark requires open chest surgery to repair lacerations to his left main bronchus
and a pulmonary vein.
Despite being given large volumes of intravenous fluid replacement (plasma
volume expander and then blood as soon as it was available from cross
matching), he could not be stabilised before surgery because of accumulating
blood and air in the pleural space, and ongoing blood loss. During surgery, he
continued to experience episodes of profound hypotension as fluid replacement
was unable to keep up with the losses.
As Mark is recovering consciousness after the surgery, which also included
stabilisation of his fractures, the anaesthetist says "We are still not keeping
ahead of this guy's losses. His pulse is about 120, systolic BP only 90 and his
peripheral perfusion is poor. Have we missed something?"
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL THREE
Tutorial 3 : Trigger 1
POST-OP
Mark's central venous pressure is monitored while his fluid replacement
continues.
The anaesthetist, who is also the hospital's intensivist, says "That is about as
high as we dare bring up the CVP. I wish we had a pulmonary wedge pressure
(PWP) to get the left ventricular filling pressure!"
What we know
Need to know
CVP:
Why measured CVP and not the blood
To measure:
pressure? Wanted to know if there is an
invasive to pressure
issue with blood coming back to the heart.
blood is banking up before it gets to right atria
in the right atria
What is highest amount he dares bring up
because the right side of the heart is not able to
Pressure
the CVP?
get the blood into the pulmonary system.
normal about
Raised level doesn’t necessarily mean that
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Septic Shock
8-12mmHg
blood volume it increasing.
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Cardiogenic Shock
Should be a difference between arterial
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Pulmonary Embolism
and venous pressure and there will be a
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Pulmonary Oedema
push back of blood. Pulmonary oedema
could be a consequence.
What is a wedge pressure? Gives a
pressure in the pulmonary artery?
Frank Starling Law: CO=HR x SV
Cardiac Filling pressure: The pressure on
the ventricles when they are stretched to
full capacity( doesn’t occur ina healthy
heart).
Hypothesis
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Right heart function can increase CVP
even when patient is hypovolaemic –
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
Blood culture- S. aureus could be a
possibility.
CVP can be raised due to intrathoracic
pressure also so if had PWP we could see
more accurately what the pressure is.
If PWP px is getting enough blood and
afterload is good.
If there is a mismatch in PWP and CVP
then there is something wrong with the
heart. PWP lower than CVP problem with
preload.
If cant get PWP – BP can be an alternative.
Bp 105/85
Pulse rate 96b/min
Worry about
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Ejection fraction
(EDV-ESV) %
With no mechanical problems must be decresed
volume coming back to the heart from the
pulmonary system.
EDV
irreversible shock.
Forward perfomance of the CO of the right
ECG shows
and left ventricles.
Irreversible shock – even though BP and HR
No mechanical
Healthy 70kg man ejection fraction is 58%
okay could still have ireversible shock due to
problems but
Right ventricle should about equal left
prolonged levels of hypoxia- must keep an eye
ventricular ejectiong
ventricle.
on vital signs.
fraction -31%
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What is pulse pressure? The
difference between systolic and
Not mechanically injured but could be
diastolic pressures.
biochemically – leading to irreversible shock eg.
So px has Pulse pressure of 20 rather than
Lysosomes degrade and En supply is effected
the normal pulse pressure of 40.
from increased acidity levels.
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What is the significance of pulse
pressure? Assuming arterial
compliance is normal that the
pulse pressure is proportional to
stroke volume.
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What is irreversible shock?
Low MAP, oedema, tachycardia, once 5
organs – 100% mortality.
Y1W1&2_ Blood on the Road
TRIGGERS
MED 1000
TUTORIAL THREE
TUTORIAL 3 : TRIGGER 2
PROGRESS
Mark's arterial blood pressure comes up to around 105/85, with pulse rate of 96
per min.
"Is he out of the woods now?" asks the student.
"After such a long period of hypotension, the worry is that he will deteriorate from
now on into irreversible shock no matter what we do..."
Echocardiography does not show any mechanical damage to the myocardium or
heart valves, but indicates that his left ventricular ejection fraction is down to
31%. When asked how bad this was the anaesthetist comments: "It could be
worse, but much below that they don't make it."
Y1W1&2_ Blood on the Road
TRIGGERS
TUTORIAL FOUR
TUTORIAL 4 : TRIGGER 1
Eight hours after his crash, Mark is in a serious but stable condition.
He is transferred to a metropolitan hospital.
MED 1000