**1. Introduction**

Shock is a life-threatening condition that leads to global tissue hypoperfusion and circulatory collapse. It can be reversible if detected, treated, and resuscitated early; otherwise it can cause multi-organ failure and death. Almost one million cases of shock are seen at the emergency department, annually in the USA [1].

Septic shock causes highest rates of mortality (40–60%), compared to other types of shock.

Identification of the cause of shock can be challenging [1].

There is no one specific vital sign that is diagnostic of shock [1].

Bedside ultrasound is a useful tool for diagnosing some types of shock. It can help to evaluate the volume status and cardiac contractility. It can detect tension pneumothorax and cardiac tamponade [2].

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

**3. Stages of shock**

volume is lost).

significance, too [2].

of shock [2].

**4. Recognition of shock**

• Pre-shock: compensated phase where patient usually has normal blood pressure.

• End-organ failure: there is irreversible organ damage and death [4].

• Shock: the compensatory mechanism of the body is overwhelmed (almost 20–25% of blood

Shock

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http://dx.doi.org/10.5772/intechopen.76242

After the airway is secured and ventilation is optimized, the circulatory status must be evaluated. Tachycardia and cutaneous vasoconstriction may be early signs of shock. Respiratory rate and pulse pressure (difference between systolic pressure and diastolic pressure) are of

Hypotension develops in late stages of shock, and its absence does not exclude shock [2].

Serum lactic acid and base deficit are good parameters for detecting the presence and severity

The cause of shock can be determined by taking good history, detailed physical examination,

and ordering for necessary investigations (e.g., imaging, bedside ultrasound) [2].

**c.** Obstructive shock (tension pneumothorax, pericardial tamponade)

Sometimes there is a combination or coexistence of more than one type of shock [2].

There is loss in intravascular volume which decreases preload and diminishes the cardiac output. Sometimes despite fluid or blood replacement, inotropes and vasopressors might need

In hemorrhagic shock, due to rapid drop in the blood volume, there is activation of the baroreceptors causing peripheral vasoconstriction and increased cardiac contractility and heart

**5. Classification of different categories of shock**

• Hemorrhagic shock (or hypovolemic shock)

• Non-hemorrhagic shock includes:

**5.1. Hemorrhagic shock (hypovolemia)**

**a.** Septic shock

to be added on [1].

**b.** Cardiogenic shock

**d.** Neurogenic shock **e.** Anaphylactic shock

**Figure 1.** Management of shock [2].

Shock management requires securing airway, controlling breathing, and optimizing circulation to ensure adequate tissue perfusion [2] (**Figure 1**).
