Hemorrhagic shock is a type of hypovolemic shock caused by severe blood loss that leads to inadequate oxygen delivery at the cellular level. Causes include trauma, postpartum hemorrhage, gastrointestinal bleeding, aneurysm rupture, and perioperative bleeding. As blood is lost, compensatory mechanisms maintain blood pressure initially but eventually fail as more than 20-30% of blood volume is lost, leading to lethal exsanguination with more than 30% blood loss. Management involves securing the airway, stopping bleeding, restoring volume with blood products rather than crystalloids, and monitoring endpoints like lactate and urine output to guide resuscitation.

1. HEMORRHAGIC SHOCK
Nimit Dalal

2. What is hemorrhagic shock?
• Hemorrhagic shock is a type of hypovolemic shock in which
severe blood loss leads to inadequate oxygen delivery at
cellular level.
• The causes of hemorrhage resulting in shock vary widely and
include trauma, postpartum hemorrhage, gastrointestinal
hemorrhage, rupture of an aneurysm, perioperative
hemorrhage.

5. PATHOPHYSIOLOGY
• At the site of hemorrhage, clotting cascade
and platelets form a hemostatic plug whereas
remote from the site fibrinolytic activity
increases, presumably to prevent
microvascular thrombosis.
• However excess plasmin activity and
autoheparinization can lead to pathologic
hyperfibrinolysis and coagulopathy.

6. CELLULAR LEVEL
• There is transition to anaerobic metabolism
which generates lactic acid, inorganic
phosphates and oxygen radicals.
• Release of Damage Associated Molecular
Patterns (DAMP) incites a systemic
inflammatory response.
• As ATP levels deplete, cellular homeostasis
fails and cell death ensues

7. CATEGORIES
• Compensated
• (0-20% blood loss)
• Feedback mechanisms to maintain blood pressure-
• 1) Atrial and ventricular stretch receptors
• 2) Baroreceptor reflexes from carotid sinus and aortic
arch
• 3) Chemoreceptor reflexes
• 4) Renin Angiotensin Aldosterone Axis
• 4)Release of vasopressin,epinephrine,angiotensin
• Results in – Tachycardia, tachypnea, increased blood
pressure, increased preload, increased stroke volume.

9. • The organs who win -
• Brain
• Heart
• Kidney
• Liver
• The organs who lose –
• Skin
• GI tract
• Muscles

10. UNCOMPENSATED
• 20-30% loss of blood volume
• The compensatory mechanisms can no longer
maintain blood pressure
• Body’s response-
• → Tachycardia, decreased CO, Increased RR,
decreased urine output.

11. LETHAL EXSANGUINATION
>30% blood loss (class iii & iv)
Severe hypotension, pulselessness, negligible
urine output
Inability to perfuse vital organs leading to
cerebral anoxia & fatal arrhythmias
Cold clammy extremities
Death

12. MANAGEMENT
• ABC of trauma
• Secure -
• Airway
• Breathing
• Circulation

13. PREHOSPITAL CARE
• Stop further bleeding- Recent studies indicates
that tourniquet application proximal to the site of
hemorrhage in the extremities saves lives without
risking amputation or extremity dysfunction, if
the patient can be quickly transported to the
hospital.
• Studies have shown that delaying resuscitation
until hemostasis has been achieved improves
survival in patients with penetrating trauma
because this approach averts dilutional
coagulopathy.

14. HEMOSTASIS
• Patients with purely abdominal or pelvic
bleeding may benefit from endovascular
occlusion of aorta as a temporizing measure
to slow hemorrhage.
• Resuscitative endovascular balloon occlusion
of aorta (REBOA) lowers perfusion pressure to
distal sites of severe hemorrhage, increases
afterload and redistributes remaining blood
preferentially to heart and brain.

15. VOLUME RESTORATION-CHOICE OF
FLUID
• Isotonic crystalloid resuscitation has been used
for decades in early management of bleeding.
However they only transiently expand the
intravascular volume & have no intrinsic
therapeutic benefit.
• Overzealous resuscitation with crystalloid dilutes
the oxygen carrying capacity and clotting factors.
• Limiting crystalloid infusion to 3L in 1st 6 hours is
recommended as a part of bundle of care for
patients with acute bleeding & trauma.

16. BLOOD TRANSFUSION
• Blood products transfusion provide a greater survival benefit as compared
to colloids/crystalloids
• TYPES-
• Red blood cells
• Plasma
• Platelets
• Cryoprecipitate
• Prospective studies show that 1:1:1 ratio of plasma to platelets to RBC’s is
safe
• TXA can be given to patients with severe hemorrhage who present within
3 hours of the starting of event.
• However all these contain citrate which can lead to hypocalcemia &
progressive coagulopathy.
• Thus emperical dosing of calcium & frequent measurement of electrolytes
is recommended.

17. MASSIVE TRANSFUSION PROTOCOL
• Traditionally, a massive transfusion was considered 10 units of PRBCs or
more transfused over a 24-hour period, but many experts now advocate
a revised definition of 10 units or more transfused over 6 hours.
• Determining when to initiate an MTP has been the subject of
considerable research. While a number of scores have been developed
for this purpose, the Assessment of Blood Consumption (ABC) score has
been validated and is easy to use. The ABC score relies on 4 parameters
that can be determined upon arrival to the ED:
• 1)Penetrating mechanism of injury
• 2)Positive FAST (Focused Assessment with Sonography in Trauma)
examination (i.e. evidence of hemorrhage)
• 3)SBP of 90 mmHg or less
• 4)Heart rate of 120 bpm or greater
• Each positive parameter receives a score of one. A score of 2 or more
predicts the need for massive transfusion with a sensitivity of 75 percent
and a specificity of 86 percent.

18. OXYGEN CARRIER AS AS AN
ALTERNATIVE TO RBC
• An ideal substance for carrying (and delivering) oxygen would have the
following characteristics:
• Rapid availability
• Effective oxygen-carrying capacity and provision of volume expansion
• Free of pathogens, to the extent possible
• Minimal side effects
• Viability over a range of storage temperatures
• Long shelf life
• Universal compatibility and elimination of crossmatching
• Cost effectiveness
• Adequate supply
• TYPES –
• 1) Hemoglobin based oxygen carriers
• 2)Perfluorocarbons

19. IDEAL RESUSCITATION FLUID
• The answer remains unclear.
• Large volume of normal saline infusion can cause
non anion gap hyperchloremic metabolic acidosis
where as large volume LR can cause metabolic
alkalosis as lactate generates bicarbonate.
• Based on current data, limiting fluid resuscitation
to 1 L or less and moving directly to blood
products appears to be the best strategy.

20. DELAYED FLUID RESUSCITATION
• Research suggests that permissive hypotension
which describes an approach that targets early
fluid resuscitation only to a SBP of 70 may
improve outcomes.
• The rationale is that aggressive fluid
administration causes dilution of clotting factors,
produces hypothermia, disrupts thrombus
formation and enhances bleeding.
• This does not apply to blunt trauma patients with
brain injury as hypotension reduces cerebral
perfusion & increases risk of mortality.

21. DELAYED FLUID RESUSCITATION
• While it is clear that resuscitation to
supraphysiological values is not necessary,
resuscitation allowing permissive hypotension in
penetrating trauma patients cannot be
recommended with confidence.
• Factors that should be considered when
determining whether this strategy is appropriate
include the patient's mental status and likelihood
of intracranial injury, likelihood of spinal cord
injury (SCI), underlying illness such as chronic
hypertension and proximity to a trauma center.

22. ENDPOINTS FOR PROLONGED
RESUSCITATION
• The following parameters may be used to guide prolonged resuscitation of traumatic shock
-
• Blood pressure: Maintain MAP above 65 mmHg for penetrating trauma, and above 85
mmHg for blunt trauma
• Heart rate (HR): Maintain between 60 and 100 beats per minute. Keep in mind that a HR in
this range may be abnormal for some patients, such as a healthy young adult with a resting
HR of 50 who presents with a HR of 90 following trauma.
• Oxygen saturation: Maintain above 94 percent.
• Urine output: Maintain above 0.5 mL/kg per hour.
• Lactate and base deficit: Monitor serum lactate and serum bicarbonate every four hours to
ensure end-organ perfusion is adequate or improving with resuscitation. Reasonable goals
of resuscitation include a serum lactate <2 mmol/L and normalization of any base deficit.
• Mixed central venous oxygen saturation: Monitor every four hours to ensure end-organ
perfusion is adequate or improving with resuscitation; goal is to maintain above 70
percent.