Indian Journal of Anaesthesia

: 2011  |  Volume : 55  |  Issue : 3  |  Page : 317--318

Red plug: An alternative to the blocked ProSeal TM laryngeal mask airway inflation valve

Bimla Sharma, Chand Sahai, Jayashree Sood 
 Department of Anaesthesiology, Pain & Perioperative Medicine, Sir Ganga Ram Hospital, New Delhi, India

Correspondence Address:
Bimla Sharma
Sir Ganga Ram Hospital, Old Rajinder Nagar, New Delhi

How to cite this article:
Sharma B, Sahai C, Sood J. Red plug: An alternative to the blocked ProSeal TM laryngeal mask airway inflation valve.Indian J Anaesth 2011;55:317-318

How to cite this URL:
Sharma B, Sahai C, Sood J. Red plug: An alternative to the blocked ProSeal TM laryngeal mask airway inflation valve. Indian J Anaesth [serial online] 2011 [cited 2021 Apr 22 ];55:317-318
Available from:

Full Text


The ProSeal TM LMA (ProSeal TM laryngeal mask airway - PLMA) is expensive and has a shorter life span than the classic LMA (cLMA). [1] The inflation valve of the PLMA is similar to that of the cLMA, and intubating LMA. It has a white polypropylene core and a stainless steel spring. [2]

We report the successful exchange of seven blocked non-functioning inflation valves with the functioning valves of discarded cLMA/PLMA. The repaired PLMAs were subjected to the tests recommended by the manufacturer before autoclaving and subsequently before use. [2],[3]

Successful replacement of damaged cLMA inflation valves and repair of PLMA inflation line using functioning valves or PVC inflation lines taken from various sources have been reported. [4],[5]

On three occasions, when we failed to get a replacement, we bypassed the non-functioning inflation valve of the PLMA, by using the red plug [Figure 1] to inflate the cuff of the PLMA without any problem. The red plug is a vent device integrated into the inflation valve-pilot balloon assembly of the PLMA. [2],[6] Till date, we have conducted 20 laparoscopic procedures using the red plug to inflate the PLMA cuff without compromising the safety of the patients.{Figure 1}

Failure to inflate the cuff, secondary to obstruction of the pilot balloon may be due to mechanical blockage (chemical residue, damage to valve by chemical agents used during cleaning or sterilisation, moisture or aging of the valve).[7],[2] The manufacturer recommends discarding reusable LMAs after a maximum of 40 uses or when these devices fail the pre-use check tests. In many institutions, their use may extend beyond the recommended 40 uses or they may be used when the damaged part has been repaired and the LMA has fulfilled the pre-use check tests. [8],[5]

Encouraged by our experience, previous reports, [4],[5] failure of the manufacturer to replace damaged inflation valves and the high cost of the reusable LMAs, we now retain functioning inflation valves of LMAs slated for condemnation.


1Doneley S, Brimacombe J, Keller C, von Goedecke A. The ProSeal TM has a shorter life span than the classic TM laryngeal mask airway. Anesth Analg 2005;100:590-3.
2Brimacombe J. Laryngeal Mask Anesthesia. Principle and Practice. 2 nd ed. London: WB Saunders; 2005.
3LMA-ProSeal TM Instruction Manual. Northfield House, Nothfield End, Henley on Thames, Oxon, UK, The Laryngeal Mask Company Limited, 2002. Available from: [Last accessed on 2011 Feb 03].
4David PM, Andreas WL, Alex TM, Craig MS. Exchanging malfunctioning inflation valves in laryngeal mask airways. Anesthesiology 2001;95:A505.
5Kundra P, Nisha B. Damaged ProSeal LMA inflation line can be repaired. Indian J Anaesth 2010;54:481.
6LMA- ProSeal TM Supplementary Instructions for Use. The Laryngeal Mask Company Limited, Northfield House, Northfield End, Henley on Thames, Oxon, UK. 2002. Available form: [Last accessed on 2011 Feb 03].
7Wat LI, Brimacombe JR, Gee S. Laryngeal mask airway longevity and pilot-balloon failure. J Clin Anesth 1997;9:432.
8Wong DT, McGuire GP. Fractured laryngeal mask airway (LMA). Can J Anesth 2000;47:716.