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A I R W A Y
M A N A G E M E N T
D eveloping designs
When originally developed, the LMA was a heat-sterilizable, reusable
device made of silicone. Today, single-use devices are also available,
which most clinicians prefer, citing concerns of device breakdown
over time and the possibility of patient cross-contamination with
reuse.
The original LMA, and devices like it, are currently known as "classic" models. They provide low-pressure seals around the glottic aperture to facilitate oxygenation and ventilation. In patients with known
difficult airways, intubating LMAs provide an easy-to-use system
designed to intubate the trachea with an endotracheal tube advanced
through the LMA's ventilation channel. This can be done blindly or
with videoscopic assistance on some models.
Some LMAs have been developed with separate channels through
which an orogastric tube can be advanced into the stomach for decompression of acid or air. Flexible LMAs provide ventilation lumens that
are wire-reinforced, which increase the flexibility of the tube without
disrupting the seal at the glottis. These devices are often used in eye or
ENT procedures, because the ventilation channel can be manipulated
out of the surgical field without compromising ventilation. Some LMAs
also have integrated bite blocks, which prevent occlusion of the ventilation channel by reflexive masseter spasm during emergence.
There are many clinical benefits associated with LMA use. In procedures requiring general anesthesia without muscle paralysis, the LMA
is an outstanding tool that allows spontaneous ventilation. It provides
the benefits of mask ventilation without such drawbacks as leaks or
poor mask seals. In patients with known or unanticipated difficult airways, it can be used as a rescue device to provide ventilation and oxygenation. It has become the go-to device in scenarios where intubation is not possible and mask ventilation is challenging.
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O U T PAT I E N T S U R G E R Y M A G A Z I N E O N L I N E | O C T O B E R 2013
