Utility of Laryngeal Mask Airway for the airway management in infants undergoing operative procedures for retinopathy of prematurity: A single arm clinical trial

·      **Study Design:**A single arm clinical trial

·      **Study Site:**Operating Room of Rajendra Prasad Centre of Ophthalmology at All India Institute of Medical Sciences, New Delhi.

·      **Ethics and Consent:**Study will be started after approval from institutional ethical committee and registration in Clinical Trial Registry of India. Patients will be enrolled only after a written informed consent from guardians of the patients in their local language.

·      Inclusion criteria:

·      Infants (<1 year of age) of either gender posted for any ROP intervention in the OT.

·      Patients belonging to American Society of Anesthesiologists’ Physical Status Grade I, II or III.

·      Guardians giving willful consent for the participation in the study.

·      Exclusion criteria:

·      Patients with restricted mouth opening.

·      Patients with airway obstruction.

·      Patients with distorted airway.

·      Patients with history of stiff lungs, recent pneumonia.

·      Patients with history of recent upper respiratory tract infections.

  Â·      Methodology:

·      Written and Informed consent will be taken from the guardians.

·      After confirming fasting duration, patient will be shifted to the operating room.

·      ASA Standard II Monitoring will be instituted.

·      Inhalational induction of anaesthesia will be done using 100% O2 and titrated doses of Sevoflurane and maintenance of anaesthesia will be done using 50% O2 in air and titrated doses of Sevoflurane to maintain minimum alveolar concentration (MAC) >1.

·      An appropriately sized intravenous cannula will be secured.

·      Administration of Injection Fentanyl (0.5–1 mcg/kg) and Injection Atracurium (0.2–0.5 mg/kg) will be on discretion of  anaesthesia consultant.

·      Weight appropriate supraglottic airway device will be selected based on manufacturer’s guidelines. Mostly such infants will be weighing <5kg so LMA size 1 will be used, which is the smallest size in all generations of supraglottic devices.

·      The type of LMA will be decided by the concerned anaesthesia consultant and surgeon. A senior anaesthetist experienced in paediatric cases and supraglottic airway devices will only insert the LMA and confirm the placement. Successful insertion of LMA will be defined on confirming the ventilation with capnograph, chest rise, and acceptable leak without overtly increasing airway pressure.

·      If fail to ventilate or/and secure the airway, other rescue measures including endotracheal intubation, or awakening the patient can be attempted by the concerned anaesthetist depending upon the situation.

·      The LMA will be removed in an awake state and the patient will be observed for any complication in the neonatal intensive care unit (NICU).

·      The following parameters will be studied.

Parameters:

·      **Success:**Number of attempts needed to insert and secure the LMA with confirmed ventilation will be counted and noted.

·      The oropharyngeal leak pressure (OPLP) will be checked by choosing manual ventilation mode on the ventilator, closing the adjustable pressure limiting valve to 40cmH2O and setting the fresh gas flows to 3L/min. OPLP will correspond to the sustained airway pressure in this configuration.

·      The duration of insertion will be measured from picking up of LMA to the confirmation of LMA placement by two square wave patterns in the capnogram on the monitor.

·      The ease of insertion will be defined by objective criteria as mentioned in the Table 1.

Easy placement

Difficult placement

|Time for insertion

<30sec

30sec

|First Attempt success rate

Success

Failure

|Adjuncts or Manoeuvres

No

Yes

Table1: Objective criteria for defining easy vs difficult placement of LMA.

·      A difficult placement will be defined by the presence of any one criterion while an easy placement can only be defined by presence of all three criteria.

·      The leak percentage will be calculated by the following formula.

·      Any Incidence of desaturation or bradycardia requiring intervention/treatment, LMA displacement, re-insertion, and need for endotracheal intubation and mechanical ventilation will be noted.

·      Occurrence of post extubation apnea will be noted ( a pause in breathing more than 15 seconds requiring intervention.

·      Occurrence of any postoperative airway complication or evidence of airway trauma (i.e., presence of blood-tinged secretions on the dorsum of the LMA cuff) will be noted.