Exclusion Criteria:

• 1. Interstitial lung disease, chest wall disease, or bronchospastic disease with no flare-ups in the past 2 weeks of presentation
• 2. History of difficult intubation or ventilation
• 3. Airway malformation
• 4. Congenital heart disease
• 5. Cardiac arrhythmias
• 6. Central nervous system disease, including developmental delay, cerebral palsy, or seizure disorder
• 7. History of or family history of malignant hyperthermia
• 8. Electrolyte disorders
• 9. Gastrointestinal disease
• 10. Hepatic dysfunction
• 11. Renal dysfunction
• 12. Metabolic disease, such as diabetes
• 13. Obesity, defined as a body mass index greater than the 95% percentile for age
• 14. Preterm infant (less than 37 weeks gestational age) 15. Use of any medications (anticonvulsants, opioids, benzodiazepines, antibiotics, antihistamines drugs that induce hepatic enzymes) that may affect MAC.
• Inclusion Criteria
• All patients age 1 month- 3 years presenting for surgery.