Single-tube, double-tube, reinforced: How different laryngeal masks demonstrate their unique capabilities

In the toolbox of airway management, the laryngeal mask airway, with its dual advantages of non-invasiveness and efficient sealing, serves as a bridge connecting the face mask and the endotracheal tube.From single-tube to double-tube, and then to the reinforced design, the iterative upgrades of the laryngeal mask airway family have precisely covered the needs of different clinical scenarios, making it an all-around team for airway management.

The single-tube laryngeal mask airway (LMA) is the basic model in the LMA family. Its simple design, containing only a single airway tube, makes it suitable for short surgeries on the limbs and body surface. Its advantage lies in its ease of operation; it can be quickly inserted without complex techniques, making it particularly suitable for emergency departments and painless bronchoscopy procedures where rapid airway establishment is crucial. For example, in many hospitals and institutions, the use of single-tube LMAs exceeds 60% in ENT general anesthesia surgeries. However, the single-tube LMA has limited sealing and cannot effectively prevent gastric reflux, making it more suitable for patients with a low risk of reflux.

The dual-tube laryngeal mask airway (LMA) is an upgraded version of the LMA family, adding a drainage tube next to the main ventilation tube to form a dual "ventilation-drainage" channel. Its ventilation mask uses a double-bag design, achieving a sealing pressure of 30-40 cmH₂O, more than 50% higher than a single-tube LMA, significantly reducing the risk of reflux and aspiration. This feature makes it the first choice for prolonged surgeries, special patient positions (such as prone orthopedic surgery), or patients at high risk of reflux (such as postpartum women and obese patients). Taking the LMA ProSeal as an example, its back cuff can push the ventilation mask towards the laryngeal tissue, reducing the probability of intraoperative air leakage, while the drainage tube can be inserted into a gastric tube to aspirate gastric contents, achieving dual protection against reflux and ensuring ventilation.

The reinforced laryngeal mask airway (LMA) is a special force in the LMA family. With its built-in spiral metal or nylon wire, it provides resistance to kinking, maintaining an unobstructed airway even when the head and neck position changes or the airway is compressed. This design makes it particularly effective in head and neck surgeries (such as thyroid surgery and maxillofacial surgery), and it is especially suitable for prone spinal surgery, avoiding the kinking of the LMA caused by body pressure.Furthermore, the length and curvature of the reinforced laryngeal mask airway are specially designed to prevent excessive head tilting during insertion, reducing the risk of cervical spine displacement and balancing airway management with spinal stability. However, its metallic composition limits its application in scenarios such as MRI scans, and its higher cost limits its use to specific surgical needs.

The choice of laryngeal mask airway (LMA) type requires a comprehensive consideration of factors such as surgical duration, patient positioning, and airway risk. Single-tube LMAs are preferred for short surgeries to quickly establish an airway; double-tube LMAs are preferred for longer surgeries or surgeries with a high risk of regurgitation to improve safety; and reinforced LMAs are preferred for head and neck surgeries or surgeries involving complex positioning to ensure ventilation stability. While new LMAs are constantly being optimized in terms of materials and structure with technological advancements, the basic design principles of single-tube, double-tube, and reinforced LMAs remain the core logic for precise application.

From light cavalry to a safety shield, and then to special forces, each iteration of the laryngeal mask airway family aims to protect patients' airways in a more scientific way. In the future, with the integration of visualization and intelligent technologies, laryngeal masks are expected to play an even greater role in airway management, making every breath safer and more comfortable.