Hypovolemic Shock

Abdullatiff Sami AL-RashedBlock 3.2

Collage of Medicine, KFUAl-Ahsa, Saudi Arabia

Presentation Outline

The Case

Mustafa a 22 years old Saudi medical student was driving his car at a speed of 145 Km/Hour without fastened his seatbelt when he was involved in a single-vehicle automobile accident.

Mustafa a 22 years old Saudi medical student was driving his car at a speed of 145 Km/Hour without fastened his seatbelt when he was involved in a single-vehicle automobile accident.

When attended to by Red Crescent emergency team personnel, no information was available about the time of the accident

When attended to by Red Crescent emergency team personnel, no information was available about the time of the accident

The Case

He was found to be agitated and complaining of abdominal pain. His airway was patentHe was found to be agitated and complaining of abdominal pain. His airway was patent

At the scene, he was breathing at 32 breaths/ min with BP of 90/60 mmHg and a pulse of 130 Bpm. At the scene, he was breathing at 32 breaths/ min with BP of 90/60 mmHg and a pulse of 130 Bpm.

He was placed in a hard cervical collar on a back board and transported to the emergency roomHe was placed in a hard cervical collar on a back board and transported to the emergency room

The Case

Upon arrival his vital signs were the same, with temp. of 36 C. His abdomen was markedly distended. His hands and feet were cold, his legs mottled.

Upon arrival his vital signs were the same, with temp. of 36 C. His abdomen was markedly distended. His hands and feet were cold, his legs mottled.

A NG tube revealed green liquid. A urinary catheter revealed dark yellow urine. His Hb is 7. His FAST examination is positive in Morrison’s Pouch.

A NG tube revealed green liquid. A urinary catheter revealed dark yellow urine. His Hb is 7. His FAST examination is positive in Morrison’s Pouch.

The Questions

IntroductionIntroduction

Hypovolemic Shock

• Hypovolemic shock is an emergency condition in which severe blood and fluid loss make the heart unable to pump enough blood to the body due to decreased preload.

• The diminished preload decreases the CO and the SVR increases in an effort to compensate for the diminished CO and maintain perfusion to the vital organs.

• It leads to multiple organs failure.

Causes of Hypovolemic Shock

Causes of Hypovolemic Shock

Causes of Hypovolemic Shock

Classification

3/ What acid/base category would be expected.

The Answer

• The effect of fluid loss on acid-base balance is variable.

• Although many patients maintain a normal extracellular pH, either metabolic acidosis or metabolic alkalosis can occur.

• Lactate acidosis is common in cases of hypovolemic shock.

The Answer

• Lactic acidosis , considered a type of metabolic acidosis, is a physiological condition characterized by low pH in body tissues and blood (acidosis) accompanied by the buildup of lactate.

• Lactic acidosis is characterized by lactate levels >5 mmol/L and serum pH <7.35.

• Type A lactic acidosis is the most common type of lactic acidosis in hypovolemic shock

4/ What is the effect of this kind of shock on kidneys,

heart, lungs, brain, and intestines.

Kidneys

• The urine output will decrease do to renal hypoperfusion.

Blood loss 750-1500ml

Blood loss 1500-2000

Blood loss >2000

Urinary output mildly affected

Urinary output mildly/severely affected.

Severe oliguria or anuria

Heart

• Cardiovascular signs are due to adrenergic response to blood loss.

(Shock class I) (Shock class II) (Shock class III) (Shock class IIII)

NONE Tachycardia due to catecholamine release.

Weak pulse or absent pulses (they are more significant than weak pulses).

Skin: pale, moist and cool.

Tachycardia

Hypotension

Tachycardia, very weak pulse.

Capillary refill is undetectable.

The skin is pale and moist.

Blood pressure very low or undetectable.

Lungs

• Tachypnoea due to central nervous system chemoreceptor stimulation by a decreased pH and hypoxia.

Brain

• Symptoms are duo to cerebral hypoperfusion and acidosis.

(Shock class I) (Shock class II) (Shock class III) (Shock class IIII)

None or orthostatic dizziness.

Restlessness, anxiety, agitation.

Anxiety, confusion.

Confusion, drowsiness, and coma

Intestine

• Decreased intestinal motility due to intestinal hypoperfusion.

• This leads to bilious aspirate “Green liquid in Nasogastric tube aspirate”

5/ What would be the cardiac output.

The Answer

• Hypovolemic shock is characterized by a loss in intravascular volume that results in decreased preload.

• Since preload is one of the determinants of stroke

volume, cardiac output falls.

The Answer

• The initial hemodynamic abnormality of fluid loss activates the compensatory mechanisms under neuroendocrine control, which maintain adequate central perfusion despite the fall in cardiac output.

• However, systemic vasoconstriction may lead to tissue ischemia, hypoxia, and eventually to altered cellular function and global organ dysfunction.

Hypovolemic Shock