Placement of the PLMA was achieved by threading a gum elastic bougie (Portex-SIMS; Hythe, Kent, UK) into the drain tube, and, under gentle direct laryngoscopy, its distal end was introduced into the esophagus. Positive-pressure ventilation was instituted and, via the multiport adaptor, the BB was passed into the left mainstem bronchus under bronchoscopic guidance, carefully avoiding the tracheal mass. A gastric drainage tube was gently inserted via the drainage port to drain the stomach. Adequate one-lung ventilation (OLV) was achieved after inflation of the BB cuff in the lateral decubitus position. Throughout the period of OLV, peak inspiratory pressures ranged from 30 to 35 cmH2O on pressure-controlled ventilation with tidal volumes of 400 to 450 mL, a respiratory rate of 12, and end-tidal CO2 of 45 to 48 mmHg. Surgical exposure was good, and surgery proceeded uneventfully. Postprocedure bronchoscopy did not reveal any evidence of aspiration in the larynx or tracheobronchial tree.
The patient had a friable tracheal mass close to the vocal cords that precluded the placement of an endotracheal tube and had the potential for tumor trauma. We used a supraglottic airway to mitigate this and chose the PLMA in view of the patient’s aspiration risk, taking advantage of the probable added protection of a gastric drainage tube. Although a reduction in aspiration risk with the PLMA (compared with the CLMA) has not been shown, the drainage tube successfully vented regurgitated fluid and protected against aspiration. 2 In more than 2,000 PLMA placements, there were 12 cases of clinically apparent regurgitation with no clinical or bronchoscopic evidence of aspiration. 2
The measured peak airway pressures of 30 to 35 cmH2O were high probably because of reduced lung compliance. These pressures are within the appropriate “lung-protective ventilation” strategy of limiting the peak inspiratory pressure to <35 cmH2O during OLV. 3 The reported improved seal of the PLMA as compared with the CLMA was to our advantage. Median seal pressures with PLMA are reported to be approximately 30 cmH2O, 4 with pressures exceeding 40 cmH2O in 20% of cases. 5 The airway seal with CLMA is reported to exceed 30 cmH2O in only 4% of cases. 5 Our approach was an effective strategy in the management of this uncommon yet challenging scenario. We suggest that it be considered as part of the armamentarium for such cases requiring lung separation.