Trauma And Shock

Question 1

What is shock

Answer 1

Shock is a life-threatening manifestation of circulatory failure.

Question 2

Physiology

Answer 2

The major physiologic determinants of
tissue perfusion (and systemic blood pressure [BP]) are
cardiac output (CO) and systemic vascular resistance
(SVR):
BP = CO X SVR
CO is the product of heart rate (HR) and stroke volume
(SV):
CO = HR X SV
The stroke volume is determined by:
●Preload
●Myocardial contractility
●Afterload

Question 3

SVR is governed by:

Answer 3

●Vessel length
●Blood viscosity
●Vessel diameter (ie, vessel tone)

Question 4

Stages of shock
Pre-shock or compensated shock:

Answer 4

Characterized by compensatory mechanisms to
counter the decrease in tissue perfusion,
including tachycardia, peripheral
vasoconstriction, and changes in
systemic blood pressure

Question 5

Stages of shock
Shock

Answer 5

During this stage, most of the classic
signs and symptoms of shock appear due to
early organ dysfunction, resulting from the
progression of the pre-shock stage as the
compensatory mechanisms become insufficient

Question 6

Stages of shock
Decompensated shock/End-organ dysfunction -

Answer 6

This is the final stage, leading to irreversible
organ dysfunction, multiorgan failure, and death

Question 7

TYPES OF SHOCK

Answer 7

Hypovolemic: haemorrhagic vs nonhaemorrhagic
▪ Cardiogenic
▪ Extracardiac obstructive
▪ Distributive

Question 8

Haemorrhagic

Answer 8

Reduced intravascular volume
from blood loss can result in shock. There are
multiple causes of hemorrhagic shock, of which
blunt or penetrating trauma
Trauma patient:
4 and 1 on the
floor
chest, abdomen,
pelvis, long
bones and on
the floor
▪ The shock index assists in grading
shock: SI =pulse/systolic BP
▪ Predicts outcome
▪ <0.7, no shock
▪ 0.7-0.9 mild shock
▪ 0.9-1.1 moderate shock
▪ >1.1 severe shock

Question 9

Distributive

Answer 9

Distributive shock is characterized by severe
peripheral vasodilatation (vasodilatory shock). Molecules that
mediate vasodilatation vary among the etiologies

Septic shock:
Treatment includes:
fluid bolus, reassessment
of end
points of resus,
broad spectrum
Abos, source
control
Distributive — Distributive shock is characterized by severe
peripheral vasodilatation (vasodilatory shock). Molecules that
mediate vasodilatation vary among the etiologies
1. Septic shock
2. SIRS
3. Anaphylactic
4. Neurogenic

Question 10

DIAGNOSIS/RECOGNITION

Answer 10

DIAGNOSIS/RECOGNITION
ORGAN SYSTEM SIGNS/SYMPTOMS CAUSE
CVS Mental status changes
(Agitation/anxiety/coma)
Decreased cerebral perfusion
CVS Tachycardia,
Atrial/Ventricular
dysrrhythmias
Hypotension
Decreased CVP
Adrenergic stimulation
Coronary ischaemia
-coronary ischaemia
-right heart failure
-decreased systemic, vascular
resistance
-decreased venous return
Hypovolaemia
Resp Tachypnoea
Cyanosis
Pulmonary oedema, sepsis
Compensation for metabolic
acidosis
Hypoxia
Renal Oliguria Decreased perfusion, afferent
arteriolar vasoconstriction
Skin Cool, clammy,
warm, dry
Vasoconstriction
Vasodilation

Question 11

Why is it important to identify the
type of shock?

Answer 11

Management
differs for each
category

Question 12

Fluid therapy

Answer 12

Minimum of 2 large bore (14 to 16 gauge) intravenous catheters
▪ Isotonic fluid infusion (up to 200ml/min) Ringers lactate/normal saline
▪ Fluid challenge of 10 – 25ml/kg and then reassessment (+ 2000ml to 70kg pt)
▪ Blood for arterial blood gas analysis, screening and typing
▪ If blood pressure returns to normal, the volume loss was small & the only Rx
required may be infusion of isotonic fluid.
▪ If the increase in bp is transient, there might be a need for blood transfusion.
▪ Those who continue to require large amounts of fluid and blood, have ongoing
bleeding and require surgical intervention
▪ Endpoint of resuscitation: urine output of 0.5 – 1ml/kg/hr, any improvement in organ
perfusion, hypotension, tachycardia, GCS, clearance of lactate etc.