Effect of Intravenous Metochlopramide Prophylaxis on Gastric Volume

Since regional anaesthesia has largely replaced general anaesthesia, the risk of aspiration pneumonitis during caesarean sections has significantly decreased. Nevertheless, prophylaxis against gastric aspiration is still important in patients in whom regional anaesthesia is contraindicated or in whom general anaesthesia has to be administered (for example; during emergency caesarean delivery). The administration of intravenous anaesthetics reduces the level of consciousness of a patient that compromises the protective reflexes of the upper airways. Moreover, a high level of sedation also reduces the tone of the LES (lower oesophageal sphincter). Both these situations predispose the risk of aspiration pneumonia in patients awaiting surgical interventions in supine position under general anaesthesia.

The risk of aspiration increases in outpatients if the volume of the gastric contents increases beyond 25 ml and its pH falls below 2.5. However, the risk of aspiration significantly decreases in "fasted" outpatients. Since most patients awaiting elective surgery remains fasted, routine prophylaxis for preventing aspiration pneumonitis is not recommended anymore.

the administration of intravenous metoclopramide and cimetidine across patients (n=20) awaiting laparoscopic gynaecological surgery significantly increased the pH of the gastric contents in the intervention group compared to their control counterparts (6.1 versus 2.7, p<0.05). The mean aspirated volumes were also significantly lower in the intervention group compared to their age-matched controls (6.9ml versus 15.3ml, p<0.05). Hong (2006) further showed that the percentage of individuals with high-risk gastric volume (>25 ml) and low pH (<2.5) was higher in individuals who did not receive intravenous metoclopramide and cimetidine prior to surgery compared to their counterparts who received such interventions (20% versus 5%, p<0.05) .

Inclusion criteria

• pregnant women belonging to the age range between 22 to 38 years and who provided informed consent to participate.

Exclusion criteria

• a neurological and psychological disorders
• renal or hepatic diseases
• chronic gastroesophageal reflux diseases
• refusal to consent