This study evaluates the effect of combining non pharmacological anti emetic prophylaxis, namely peppermint essential oil to granisetron and dexamethasone in patient who receive intrathecal morphine for lower segment cesarean section. Half of the patient will receive nasal strip containing peppermint essential oil in addition to granisetron and dexamethasone while the other half will only receive granisetron and dexamethasone.

It is not uncommon to use different group of anti emetic in order to achieve high successful rate in the prevention of opioid induced nausea and vomiting. This study evaluates the effect of combining non pharmacological and pharmacological method to prevent such condition.

Aromatherapy has been used since many years to treat nausea and vomiting. One of the proposed mechanism is by the activation of olfactory receptor when the molecules of essential oil absorb in the mucus lining olfactory epithelium. The signal is then carried by olfactory sensory neuron to the olfactory bulb which filters and send signal to olfactory cortex as well as limbic system to give the feeling of well being.

Granisetron is a serotonin 3 receptor antagonist prevent or treat nausea and vomiting by competitively blocks the action of serotonin at 5-hydroxytryptamine 3 (5HT3) receptors while the mechanism of action of dexamethasone; which is a glucocorticoids is not fully understood.

Inclusion Criteria:

• American Society of Anesthesiologists (ASA) I and II.
• Non-smoker.
• BMI =< 40
• Singleton pregnancy

Exclusion Criteria:

• Patient with known allergy to granisetron, dexamethasone, bupivacaine, fentanyl, morphine, paracetamol, celecoxib, ginger oil.
• Patient who has inability to breathe through nose.
• Patient with history of post-operative nausea and vomiting (PONV) or motion sickness