A Prospective, Randomized study comparing the Intraocular pressure changes and hemodynamic responses to insertion of Laryngeal mask Airway and Endotracheal Intubation in elective paediatric ophthalmic surgeries

SUMMARY

In the present study 60 patients belonging to ASAI& II of both sexes between age group 2 and 12 years were studied in two groups of 30 each as laryngeal mask airway group (LMA group/ group A) and Endotracheal tube intubation (ETT group/ group B). The data of both the groups were compiled and statistically analysed using Student ‘t’ test and p value was calculated. The IOP in LMA group was not raised during and after insertion of LMA. And remained progressively less at 30 seconds and 2 minute of study. In ETT group, the IOP had an initial fall after induction and later rose at 30 seconds  2nd  minute of intubating the trachea. (P<0.001). Statistically the rise in IOP was highly significant. The heart rate in LMA group showed a declining trend during an after induction, insertion and throughout the study. Whereas in ETT group after induction, there was an initial fall in heart rate from the baseline value. Then at 30 seconds and 2 minutes of insertion of tracheal tube the heart rate had progressive increase (p<0.001) In LMA group the systolic & diastolic blood pressure are decrease from its baseline value, after induction, during insertion and at 30 seconds and 2 minute of insertion. But blood pressure remained within physiological limits. 70 In ETT group ,the systolic & diastolic pressure had          an initial fall after induction and later on showed a rising trend at 30 seconds and 2 minutes of insertion of endotracheal tube.(p<0.001)

Hence this study is in favor of use of LMA to a conventional use of endotracheal        for administrating general anaesthesia specially for haemodynamically compromised patients and intraocular surgeries. Laryngoscopy and tracheal intubation is a time-tested method to achieve the airway control in anesthesia practice and resuscitation. However, it is associated with significant rise in IOP and cardiovascular response in the form of raised blood pressure and tachycardia because of sympathetic discharge following laryngotracheal stimulation . Many workers      have  made attempts     in       the     past   to      mitigate       or      prevent cardiovascular and ocular reactions especially the acute increase in intraocular pressure (IOP) associated with laryngoscopy and endotracheal intubation. Use of Brains’ laryngeal mask airway (LMA) as an alternative to endotracheal tube has attracted the attention of several workers with regard to haemodynamic and IOP changes.

CONCLUSION

1. Air way can be secured with confidence by LMA

2)      The art of placing LMA can be learnt very easily

3)      There is no difficulty in maintaining the anesthesia at desired level

4)      Patient tolerance to LMA is very good

5. The IOP does not raise when LMA is used hence can be safely used in patients with already raised IOP like  in Glaucoma and in penetrating eye injuries.

6. Endotracheal intubation is associated with rise in IOP, heart rate, and blood pressure.

7. Reusable LMA is  cost effective when compared with ETT since a single reusable LMA can be used uptill 20 times after ETO sterilization.

 8) LMA can be used safely in patients who are haemodynamically compromised

The present study concludes that use of LMA as more beneficial when compared to ETT for general anesthesia in the group of patients studied