What is Hypovolaemic Shock & its treatment

Introduction

Hypovolaemic shock occurs due to reduction in total blood volume

A shock is a condition in which circulation fails to meet the nutritional needs of the cells and at the same time fails to remove the metabolic waste products.

Peripheral circulatory failure arises from an imbalance between the vascular bed size and the intravascular fluid volume

The primary cause of shock is the reduced blood flow state in vital organs.

Shock can be hypovolaemic, cardiogenic, distributive, septic , neurogenic/anaphylactic, acute adrenal insufficiency or obstructive or endocrine

Hypovolaemic Shock

It can be due to haemorrhage, severe burns which results in loss of plasma or loss of fluid in case of severe vomiting and diarrhoea of any cause

The characteristic features are decreased filling pressure of the heart, decreased systemic arterial pressure, tachycardia and increased vascular resistance.

haemorrhagic shock

A loss of more than 30-40% blood volume results in a fall in blood pressure and gross hypoperfusion of the tissues leading to haemorrhagic shock

Features

The primary problem is a decrease in preload.

A decrease in preload results in a reduction in stroke volume.

Features depend on the degree of hypovolaemia.

Severe shock results in:

• tachycardia
• low blood pressures
• decreased urine output
• sweating
• cold periphery
• restlessness
• air hunger

late stages of hypovolaemic shock shows :

• cyanosis
• anuria
• jaundice
• drowsiness

Treatment

Restoring blood volume, tissue perfusion, and oxygenation to normal as early as possible is the primary objective.

Replace the lost blood volume

To replace blood loss, administer 2-3 times the volume lost with crystalloids

Ringer lactate is the crystalloid of choice. Large volumes of saline infusion can cause hyperchloraemic metabolic acidosis.

When replacing lost blood volume with colloids, administer a volume equal to the lost volume.

During the initial phase of resuscitation, prefer crystalloids .

If a large volume of blood is lost, consider administering colloids such as gelofusine or 5% albumin to reduce the required infusion volume.

A blood transfusion might be necessary in cases of significant blood loss.