Isoflurane Versus Propofol for Removal of LMA in Children

The study will be done in paediatric patients by comparing two different techniques of Laryngeal Mask Airway (LMA) removal under deep anesthetic plane.

The both study techniques will be compared for safe LMA removal on the basis of adverse airway events and emergence time duration and recovery room stay timing.

* Study will be start after confirming the approval of institutional ethical review committee and after fulfilling the study inclusion criteria. The detailed study protocol will be explain to the parent/guardian and written \& informed consent will be taking on his/her will.
* Inclusion Criteria

  * Age between 2 to 10 years,
  * American Society of Anaesthesiologists (ASA) physical status I \& II,
  * Patient is not contraindicated to Laryngeal Mask Airway insertion,
  * Elective below umbilical general surgical procedures
  * patient is planned for general anesthesia with spontaneous breathing.
* Fifty patients will participate in both study groups.
* All patients will be premedicated with oral midazolam 0.3mg/kg, 45 to 60 minutes prior to induction.
* After arrival of patients in operating room, routine anesthesia monitoring will be applied and baseline blood pressure, heart rate, respiratory rate and oxygen saturation will be recorded.
* Patient will be induced with anesthetic induction inhalational agent (sleeping drug) sevoflurane 8% with oxygen by pediatric anesthesia circle system. The sevoflurane concentration will be adjusted to 3% to 4% once the adequate depth of anesthesia achieved, as evident by jaw relaxation and tolerance of an oral airway.
* The LMA will be placed after the insertion of intravenous line.
* The LMA size will be determined as per manufacturer's recommendation; which suggest 1.5 LMA size for 5-10 kg, size 2 for 10-20 kg and size 2.5 for 20-30 kg.
* The anesthesia will be maintained with isoflurane in 60% nitrous oxide and 40% oxygen. Patients will be ventilated by spontaneous mode by 'Mapleson F anesthesia circuit' and for above 25 Kg patient, the circle system will be used.
* Caudal analgesia was standardised in both study groups.
* Prior to LMA removal in group-I, isoflurane MAC awake (MAC less than 0.5) will be achieved in expiratory gases with 60% nitrous oxide and 40% oxygen. Propofol 1 mg/Kg will be combined with Isoflurane MAC awake and LMA will be removed after 20 seconds of propofol administration in group-I.

The group-II LMA will removed at end expiratory isoflurane MAC of 1.2% with 60% nitrous oxide and 40% oxygen. In both groups; LMA will be removed with inflated cuff, throat was suctioned and patients were turned into lateral recovery position.

Isoflurane and nitrous oxide were turned off and 100% oxygen supplemented till the patient had regained consciousness. All participants were transported to Post Anesthesia Care Unit (PACU) once ensured airway patency and peripheral oxygen saturation (Sp02) greater than 93% on room air. Children were allowed to wake up effortlessly in PACU at oxygen 5 litters/minutes via Hudson mask.

- The following study variables will be recorded;

1. Emergence time ( patient awakening time),
2. Duration of recovery room stay (Post anesthesia care unit),
3. Smooth Laryngeal Mask Airway removal will be assessed by

   * Cough,
   * Hypersalivation,
   * 02 desaturation \< 90%,
   * Teeth clenching,
   * Airway obstruction requiring jaw support,
   * Laryngospasm,
   * Bronchospasm,
   * Retching,
   * Vomiting,
4. Confounding variables will be assessed like;

   * Patients demographics,
   * Duration of surgery,
   * Duration of anesthesia,
   * Type of surgery,
   * Mode of analgesia
   * Number of Laryngeal Mask Airway insertion attempts:

Eligibility Criteria:
Inclusion Criteria:

* American Society of Anesthesiologist class-I \& II patients.
* mallampatis class I \& II.
* Age from 2 years to 10 years.
* Elective surgical patients for below umbilical general surgical procedures.

Exclusion Criteria:

* Congenital disorders
* Airway or facial abnormalities
* Reactive airway disease/asthma
* Anticipated difficult airway
* History of Upper respiratory tract infection in last 3 weeks
* History of gastroesophageal reflux disorders
* Known allergic to isoflurane and propofol