An oropharyngeal leak pressure or leak test is commonly performed with the laryngeal mask airway to quantify the efficacy of the seal with the airway. This value is important since it indicates the feasibility of positive pressure ventilation and the degree of airway protection from supra cuff soiling.

In adults, the I-GEL has been shown to have similar leak pressures and efficacy when compared with the Supreme^1-3 In children there is only one comparision study between two devices published recently by Jagannathan N et al in the year 2013 which demonstrated higher leak pressures for i-gel airway as compared lma supreme⁴. On comparing the other  studies involving lma supreme^5-7  and I gel^8-10 in children done separately we found that in some studies lma supreme has higher leak pressures while in some studies it was found to be equal.

Various studies have shown that insertion of supraglottic device does not cause significant  change in intraocular pressure from baseline value as compared to endotracheal tube which is associated with significant changes¹¹  Studies have found that i- gel does not cause any change in intraocular pressure from baseline value¹². Infact one study shows that I-gel insertion is associated with significantly decreased intra ocular pressure,which make it more suitable for children undergoing elective eye surgery¹³. Similar study involving LMA SUPREME is lacking.

However there is no study comparing the effectiveness, intraocular pressure changes and hemodynamic changes for both the devices in children undergoing elective eye surgery.

Primary aim of this study is to compare the oropharyngeal leak pressure of both the devices. We will also compare the ease and time for successful insertion, ease of gastric tube placement, intraocular pressure changes with insertion, pharyngolaryngeal morbidity and hemodynamic changes with both the devices in anaesthesied non paralysed children undergoing elective eye surgery.

Taking into account the most recent study we hypothesized that the I-gel would have higher oropharyngeal leak pressures to the LMA SUPREME in pediatric patients undergoing elective cataract surgery.

So due to limited number of studies and due to variation in various studies we planned to compare both the devices in children.

As we are comparing both the devices in children in terms of their effectiveness in providing ventilation we thought of comparing intraocular pressure changes and hemodynamic changes with insertion of both the devices.

References

1.      Teoh WH, Lee KM, Suhitharan T et al. Comparison of the LMA Supreme vs the i-gel in paralysed patients undergoing gynaecological laparoscopic surgery with controlled ventilation. Anaesthesia 2010; 65: 1173–79

2.      Gatward JJ, Cook TM, Seller C et al. Evaluation of the size 4  i-gel airway in one hundred non-paralysed patients. Anaesthesia. 2008; 63: 1124-30.

3.      Cook TM, Gatward JJ, Handel J et al. Evaluation of the LMA Supreme in 100 non-paralysed patients. Anaesthesia 2009; 64: 555–562.

4.      Jagannathan N, Sommers K, Sohn LE et al. A randomized equivalence trial comparing the i-gel and laryngeal mask airway Supreme in children.PaediatrAnaesth. 2013 ; 23: 127-33.

5.      Jagannathan N, Sohn LE, Chang E et al. A cohort evaluation of the laryngeal mask                                  airway-Supremeâ„¢ in children. PediatricAnesth 2012; 22: 759–64.

6.      Jagannathan N, Sohn LE, Sawardekar A et al. A randomised comparison of the LMA Supreme^TM and LMA ProSeal^TM in children. Anaesthesia 2012; 67: 632–39.

7.      Jagannathan N, Sohn LE, Sawardekar A et al. A randomised trial comparing the laryngeal mask airway Supremeâ„¢ with the laryngeal mask airway Uniqueâ„¢ in children. Anaesthesia 2012; 67: 139–44.

8.      Hughes C, Place K, Berg S et al. A clinical evaluation of the i-gel^(TM)supraglottic airway device in children. PediatrAnesth 2012; 22: 765–71.

9.      Theiler LG, Kleine-Brueggeney M, Luepold B et al. Performance of the pediatric-sized i-gel compared with the AmbuAuraOnce laryngeal mask in anesthetized and ventilated children. Anesthesiology 2011; 115: 102–10.

10.  Lee JR, Kim MS, Kim JT et al. A randomized trial comparing the i-gel ^(TM) with the LMA Classic (TM) in children. Anaesthesia 2012; 67: 606–11.

11.  Beringer RM, Kelly F, Cook TM et al. A cohort evaluation of the paediatric i-gel airway during anaesthesia in 120 children. Anaesthesia 2011; 66: 1121–112.

12.  Duman A, Ogün CO, Okesli S. The effect on intraocular pressure of tracheal intubation or laryngeal mask insertion during sevoflurane anaesthesia in children without the use of muscle relaxants. PaediatrAnaesth. 2001;11:421-4.

13.  Ismail SA, Bisher NA, Kandil HW et al. Intraocular pressure and haemodynamic responses to insertion of the i-gel, laryngeal mask airway or endotracheal tube. Eur J Anaesthesiol. 2011;28:443-8.

14.  Sahin A, Tüfek A, Cingü AK et al. The effect of I-gel â„¢ airway on intraocular pressure in pediatric patients who received sevoflurane or desflurane during strabismus surgery. PaediatrAnaesth. 2012 ; 22 :772-5.