**9. Complications of sedation**

Sedation-related gastrointestinal endoscopy complications are generally transient and of a mild degree. Nevertheless, when occur, may lead to significant morbidity and occasional mortality especially with moderate and deep sedation. Patient age, comorbidity, as well as type of sedation agent, the dose and route of administration are the most important risk factors of these complications. Serious complications can be avoided by proper pre-operative evaluation, preparation, appropriate monitoring and post-operative management. In addition, skilled treating physicians should be aware, and prepared to treat these complications. Sedation- related endoscopy complications can be divided into cardiovascular, respiratory, gastrointestinal and allergic reactions [19].

#### **9.1 Cardiovascular related complications**

Cardiopulmonary related represent 50% of serious sedation related complications and 50% of sedation related deaths in gastrointestinal procedures. Commonly, it occurs in elderly group of patients or secondary to over sedation. Cardiovascular related complications include:

#### *9.1.1 Hypotension*

Defined as systolic blood pressure less than 90 mmHg. Generally, systolic blood pressure more than 90 mmHg should maintain mean adequate arterial blood pressure to perfuse all vital organs, BP less than 90 should be treated. Benzodiazepine or opioid a lone rarely causes hypotension. However, combination of both or sedation with propofol, vasovagal attacks and hypovolemia are the most common causes of hypotension [19].

#### *9.1.2 Hypertension*

Defined as systolic blood pressure more than 160 mmHg, it is usually secondary to anxiety, pain, intubation and endoscopy.

#### *9.1.3 Cardiac arrythmias*

They are commonly observed during gastro-endoscopy. Fortunately, most of arrythmias are benign. Vasovagal attacks, pain and hypovolemia are the most common causes of arrythmia. Opioid and buscopan are associated with bradycardia [15, 19].
