Assessment of pressure–volume loop, inflation to precise pressure, minimum occlusive volume, and manual palpation techniques for inflation of endotracheal tube cuff: A randomised clinical study

Background and Aims: The endotracheal tube (ETT) is commonly used in mechanically ventilated patients to allow for proper ventilation and prevent aspiration of gastropharyngeal contents. Adequate sealing pressures are required to prevent aspiration while being low enough to maintain adequate perfusion of the tracheal mucosa. Multiple techniques exist for inflation of the endotracheal cuff. This study evaluated and compared four different cuff inflation techniques with the primary objective of measuring the volume of air needed to create an effective seal. Methods: After ethical approval and trial registration, 240 patients scheduled for surgery under general endotracheal tube anaesthesia were enroled, and 228 patients were randomised into four groups ( n = 57 per group). The ETT cuff was inflated with air according to the designated group. The techniques were compared for the volume of air required to achieve an adequate seal, cuff pressure post-intubation and just before extubation, cuff-related complications of sore throat, hoarseness of voice, and cough after extubation. Results: The manual palpation technique had the highest cuff volume, 5.7 mL [interquartile range (IQR): 5.6–5.8], and cuff pressure after inflation, 29.5 (IQR: 29.1–29.9, cmH₂O), whereas the pressure–volume loop (PVL) method had the lowest values [4.3 (IQR: 4.2–4.3) mL; 23.0 (IQR 22.7–23.4) cmH₂O] ( P < 0.001). Before extubation, Group 4 (manual palpation) again recorded the highest cuff pressure [31.3 (IQR: 30.9–31.8) cmH₂O] and cuff volume [6.0 (IQR: 5.9–6.1) mL], while the PVL group had the lowest values [24.9 (IQR: 24.6–25.2) cmH₂O; 4.6 (IQR: 4.6–4.7) mL] ( P < 0.001). Conclusion: Cuff inflation guided by the PVL method effectively maintained ETT cuff pressures and volumes within acceptable limits.