*5.4.1 Preoperative*

*Special Considerations in Human Airway Management*

To increase gastric pH, **Histamine antagonist (H2)** and **proton pump inhibitors (PPIs)** are commonly used. H2 antagonists as Ranitidine, Famotidine, and Cimetidine, act by blocking the H2 receptors of gastric parietal cells inhibiting the stimulatory effect of histamine on gastric acid secretion. **Proton Pump Inhibitors (PPIs)** as Omeprazole, Lansoprazole and Pantoprazole, irreversibly blocking the Hydrogen/Potassium ATPase of parietal cells and prevent the release of hydrochlo-

**Consumed meal/drink Minimum hours of fasting required**

1.Clear fluids 2 h 2.Breast milk 4 h 3.Infant formula/non-human milk 6 h 4.Light meal 6 h 5.Heavy meal (fried food, fatty food, meat) 8 h

The goal for enhanced gastric emptying is achieved by **prokinetics** such as Metoclopramide [23]. It stimulates the motility of upper GI and is used in risk patient to reduce gastric volume such as Gastroesophageal reflux disease (GERD), Diabetic and pregnant patients and in emergency patients who had no time to be NPO. It also has a peripheral and central Dopamine receptor antagonist activity and might reduce the risk of postoperative nausea and vomiting. Oral antacid can be used in patients with risk of regurgitation and aspiration. Antacids work by neutralization of gastric acid content, single dose 15–30 min before surgery will increase PH above 2.5. Sodium Citrate 0.3 M is non-particulate antacid that itself will not cause pulmonary damage if aspirated with the gastric fluid. Antacids increase gastric volume especially in repeated doses, but this side effect is less important than its action on increasing gastric pH. Decrease gastric volume can be achieved by 6 h fasting before surgery, naso-gastric (NG) tube used to aspirate the gastric content before anesthesia or the use of PPI like Omeprazole to inhibit

Ultrasonography has been recommended as a reliable, noninvasive, bedside tool to determine gastric volume and content in the perioperative period based on

Anesthesia management of patient with full stomach commences from preop-

erative period through intraoperative and concludes postoperatively.

relates with fluid volume gastric contents greater than 0.8 ml/kg, a high risk of aspiration [19]. However, most studies to date deal with validity considerations and propose that bedside ultrasound accurately determines gastric volume rather than contents [26]. Thus, the use point-of-care ultrasonography in the preoperative period as a screening tool has been recently advocated especially in vulnerable

cor-

many studies [24, 25]. A cutoff of antral cross-sectional area of 340 mm<sup>2</sup>

**5.2 Pharmacologic therapies**

*2017 ASA fasting guidelines recommendations.*

ric acid [22].

**Table 3.**

gastric acid secretion.

**5.3 Role of preoperative point of care ultrasound**

**5.4 Anesthesia technique for full stomach**

**112**

population.
