Page 39 - CASA Bulletin of Anesthesiology 2022; 9(2) (5)

Vol. 9, No 2, 2022

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The Laryngeal Mask Airway: Expanding Use Beyond Routine
Spontaneous Ventilation for Surgery

Shauna Schwartz, DO
Yong G. Peng, MD, PhD, FASE, FASA

Department of Anesthesiology
University of Florida College of Medicine, Gainesville, FL

Summary: The article discusses the advancements of the laryngeal mask airway (LMA) and its
routine and non-routine uses. It analyzes the risk of aspiration with the LMA compared with the
endotracheal tube. It also reviews whether mechanical ventilation is safe with the new generation
of LMAs.

Introduction

The laryngeal mask airway (LMA) was invented in 1983 by Archie Brain, MD as an
alternative airway device to the facemask and endotracheal tube (ETT) . Since the establishment
1
of the classical LMA, the device has undergone multiple improvements and modifications (Table
1). The LMA can provide a better quality of ventilation over a mask alone and with less
instrumentation to the airway than tracheal intubation. Advantages of the LMA include the ease
2
of use and less injury to airway tissues than ETTs, although trauma can result from forceful use
of LMAs . With the LMA, there are fewer hemodynamic disturbances and postoperative
3–6
complications than with an ETT . The LMA has been widely used in surgery requiring general
2
7
anesthesia and as a rescue device for difficult airways . In the updated difficult airway
algorithm, developed by the American Society of Anesthesiologists, the LMA is a priority
apparatus for emergency noninvasive airway access. Many clinical investigations and research
7
have demonstrated that the LMA is a safe and reliable airway device 2,6,8,9 . However, debate
continues regarding non-standardized use of the LMA in clinical settings, including with positive
pressure ventilation (PPV) and muscle relaxants, in laparoscopic surgery, and with obese patients
(Table 2). Concerns regarding LMA use can be categorized as follows: (1) inadequate seal of the
LMA due to malposition; (2) airway injuries ranging from throat discomfort to permanent tissue
damage; (3) aspiration risk; (4) safety of mechanical ventilation as opposed to spontaneous
ventilation; and (5) safety in obese patients. Non-routine uses of the LMA and potential safety
issues will be discussed in this review.

LMA Placement and size selection

The LMA may be easily placed following induction of general anesthesia, with or without a
muscle relaxant . In a study by Hemmerling et al., the success rate of first attempt insertion was
10
92% with the use of muscle relaxant versus 89% without muscle relaxant . If the LMA size
10
selected is too small, it may not create an adequate seal, leading to leakage, which may result in
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