Shock is caused by a sudden drop in blood flow and can result from trauma that causes blood or fluid loss. There are several types but hypovolemic shock from blood loss is most common after trauma. Symptoms of hemorrhagic shock range from mild tachycardia with up to 15% blood loss to depressed mental status and organ dysfunction with over 40% blood loss. Treatment involves rapid fluid resuscitation, controlling bleeding, maximizing oxygen delivery, and determining the need for blood transfusion or surgery. Early recognition and treatment improve the prognosis for traumatic shock patients.
2. Shock - Definition
Shock is the critical condition brought
on by a sudden drop in blood flow
through the organs.
Shock is the collapse of the
cardiovascular system, characterized by
circulatory deficiency and the
depression of vital functions.
3. Types of shock
Hypovolemic shock – caused by the loss of blood and other
body fluids.
Neurogenic shock – caused by the failure of the nervous
system to control the diameter of blood vessels.
Cardiogenic shock – caused by the heart failing to pump blood
adequately to all vital parts of the body.
Septic shock – caused by the presence of severe infection.
Anaphylactic shock – caused by a life-threatening reaction of
the body to a substance to which a patient is extremely allergic.
4. Trauma & shock
In most patients trauma is associated with
internal or external bleeding.
Hypovolemic shock
ALSO :
Neurogenic shock – Injuries of CNS
Cardiogenic shock – injury of heart, heart
tamponade, heart contusion
5. Hypovolemic Shock
an emergency condition in which severe blood
and fluid loss makes the heart unable to
pump enough blood to maintain a proper tissue
perfusion.
This results in reduction of oxygen transported
to the tissues (hypoxia); reduction of perfusion,
the circulation of blood within an organ; and
reduction of waste products transported away
from the tissue cells. Under these conditions,
body cells are able to carry on their normal
functions for only a short period of time.
6. Class I hemorrhage
Blood loss of 0-15% (<750ml)
In the absence of complications, only
minimal tachycardia is seen
Usually, no changes in BP, pulse
pressure, or respiratory rate occur.
A delay in capillary refill of longer than 3
seconds corresponds to a volume loss
of approximately 10%.
7. Class II hemorrhage
blood loss of 15-30% (800 – 1500 ml)
Clinical symptoms include tachycardia (rate >100
beats per minute), tachypnea, decrease in pulse
pressure, cool clammy skin, delayed capillary
refill, and slight anxiety.
The decrease in pulse pressure is a result of
increased catecholamine levels, which causes
an increase in peripheral vascular resistance and
a subsequent increase in the diastolic BP.
8. Class III hemorrhage
blood loss - 30-40% (1500 – 2000 ml)
By this point, patients usually have:
marked tachypnea and
tachycardia,
decreased systolic BP,
oliguria, and
significant changes in mental status, such as confusion or
agitation.
In patients without other injuries or fluid losses,
30-40% is the smallest amount of blood loss that
consistently causes a decrease in systolic BP.
Most of these patients require blood
transfusions, but the decision to administer blood
should be based on the initial response to fluids.
9. Class IV hemorrhage
blood loss: >40% (>2000 ml)
Symptoms include the following:
marked tachycardia,
decreased systolic BP,
narrowed pulse pressure (or immeasurable
diastolic pressure),
markedly decreased (or no) urinary output,
depressed mental status (or loss of
consciousness), and
cold and pale skin.
This amount of hemorrhage is immediately
life threatening.
10. Blood loss
↓ Venous return to the heart
Symphathetic reflex
catecholamins
Pain
↑ myocardial
contractility
tachycardia
Constriction
of the vessels
↑ oxygen consum-
ption in the heart
↓ BP
↓ perfusion
Anaerobic
methabolizm
acidosis
Multiple organ
dysfunction syndrom
Heart
failure
11. hemorrhage Class I Class II Class III Class IV
Blood loss <15%
<750 ml
15 - 30%
800-1500ml
30-40%
1500-2000 ml
>40%
>2000 ml
BP systolic
diastolic
No changes
No changes
No changes
↑
↓
↓
↓ ↓
↓ ↓
Heart Rate No changes
or ↑
100-120 > 120 > 120
capillary refill No changes Delayed(> 2s) Delayed (> 2s) no
Breaths normal ↑ ↑ (> 20/min) ↑ (> 20/min)
Urine output >30ml/h 20-30ml/h 10-20ml/h 0-10ml/h
Skin-limbs normal pale pale pale,cold
Mental
status
Counsious Scared or
aggressive
scared, sleepy,
aggressive
depressed
mental status (or
loss of
consciousness
12. Causes
Traumatic causes can result from penetrating
and blunt trauma.
Common traumatic injuries that can result in
hemorrhagic shock include the following:
myocardial laceration and rupture,
major vessel laceration,
solid abdominal organ injury,
pelvic and femoral fractures,
scalp lacerations.
13. Dealing with the Shock-Patient
take the history
performe the physical examination
further workup depends on the probable
cause of the hypovolemia and on the
stability of the patient's condition.
14. Initial laboratory studies
CBC,
electrolyte levels(BIO) (eg, Na, K, Cl, HCO3, BUN,
creatinine, glucose levels)
prothrombin time, activated partial thromboplastin
time,
ABGs (Arterial Blood Gases),
urinalysis (in patients with trauma)
Blood should be typed and cross-matched.
Dealing with the Shock-Patient
15. Patients with marked hypotension and/or
unstable conditions must first be resuscitated
adequately.
This treatment takes precedence over
imaging studies and may include immediate
interventions and immediately taking the
patient to the operating room.
The workup for the patient with trauma and
signs and symptoms of hypovolemia is
directed toward finding the source of blood
loss.
Dealing with the Shock-Patient
16. Imaging Studies:
If thoracic dissection is
suspected because of
the mechanism and
initial chest radiographic
findings, the workup may
include transesophageal
echocardiography,
aortography, or CT
scanning of the chest.
Dealing with the Shock-Patient
17. Dealing with the Shock-Patient
Imaging Studies:
If a traumatic abdominal
injury is suspected, a
FAST (Focused
Abdominal Sonography
for Trauma) ultrasound
exam may be performed
in the stable or unstable
patient. Computed
Tomography (CT)
scanning typically is
performed in the stable
patient.
18. Dealing with the Shock-Patient
Imaging Studies:
If long-bone fractures
are suspected,
radiographs should
be obtained.
19. Prehospital Care
The prehospital care team should
work to prevent further injury
the cervical spine must be immobilized
the patient must be extricated, if applicable, and moved
to a stretcher.
Splinting of fractures can minimize further neurovascular
injury and blood loss.
transport the patient to the hospital as rapidly
as possible
Definitive care of the hypovolemic patient usually
requires hospital, and sometimes surgical, intervention.
Any delay in definitive care, eg, such as delayed
transport, is potentially harmful.
20. initiate appropriate treatment
in the field
Most prehospital interventions involve
immobilizing the patient,
securing an adequate airway,
ensuring ventilation, and
maximizing circulation.
positive-pressure ventilation may diminish venous return,
diminish cardiac outcome
!!! While oxygenation and ventilation are necessary, excessive
positive-pressure ventilation can be detrimental for a patient
suffering hypovolemic shock.
Prehospital Care
21. TIME IS IMPORTANT !
starting intravenous (IV) lines or splinting of
extremities, can be performed while a patient
is being extricated.
procedures in the field that prolong
transportation should be delayed.
IV lines and fluid resuscitation should be
started and continued once the patient is en
route to definitive care.
Prehospital Care
22. The American College of Surgeons
Committee on Trauma no longer
recommends the use of MAST (military
antishock trousers)
Direct pressure should be applied to
external bleeding vessels to prevent
further blood loss
Prehospital Care
23. Emergency Department Care
Four goals exist in the emergency
department treatment of the patient with
hypovolemic shock:
1. maximize oxygen delivery –
- completed by ensuring adequacy of ventilation,
- increasing oxygen saturation of the blood,
- restoring blood flow,
2. control further blood loss
3. fluid resuscitation
4. pain control
Also, the patient's disposition should be rapidly and appropriately
determined.
24. Maximizing oxygen delivery
The patient's airway should be assessed
immediately
High-flow supplemental oxygen should be
administered to all patients
25. All the fluids given iv. should be warmed
Hypovolemia is worse than anaemia
Optimal oxygen supply requires Ht 30%
or HBG level 10g/dl
Fluid resuscitation
26. Fluid resuscitation
Two large bore IV lines should be
started
Initial fluid resuscitation is performed
with an isotonic crystalloid, such as
lactated Ringer solution or normal saline
An initial bolus of 1-2 L is given in an
adult (20 mL/kg in a pediatric patient),
and the patient's response is assessed.
27. If vital signs return to normal,
the patient may be monitored to ensure stability
blood should be sent for typed and cross-matched
If vital signs transiently improve,
crystalloid infusion should continue
type-specific blood obtained
If little or no improvement is seen,
crystalloid infusion should continue
type O blood should be given (type O Rh-negative blood
should be given to female patients of childbearing age to
prevent sensitization and future complications).
If a patient is moribund and markedly
hypotensive (class IV shock),
both crystalloid and type O blood should be started initially.
Fluid resuscitation
28. increased pressure causes more bleeding and
disrupts initial clots
Most of studies revealed increased survival in
the permissive hypotension
What BP is adequate but not excessive then?
Although some data indicate that a systolic BP of 80-
90 mm Hg may be adequate in penetrating truncal
trauma without head injury, further studies are
needed.
Current recommendations are for aggressive fluid
resuscitation with lactated Ringer solution or normal
saline in all patients with signs and symptoms of
shock, regardless of underlying cause.
Fluid resuscitation
29. Controlling further blood loss
external bleeding should be controlled
with direct pressure;
internal bleeding requires surgical
intervention. (craniotomy, laparotomy, thoracotomy)
Long-bone fractures should be treated
with traction to decrease blood loss.