Use of positive pressure greater than how many mmHg with a laryngeal mask airway may cause stomach inflation?

The use of positive pressure with a laryngeal mask airway (LMA) can lead to stomach inflation if the pressure exceeds a certain threshold. This is particularly relevant during ventilation as excessive pressure can overcome the lower esophageal sphincter tone, allowing air to enter the stomach instead of just the lungs.

The correct answer, indicating that a pressure greater than 20 mmHg may cause stomach inflation, is grounded in clinical practice and physiological principles. At this threshold, the intragastric pressure can exceed the pressures needed to maintain a competent lower esophageal sphincter, resulting in air entering the gastrointestinal tract. Keeping the positive pressure ventilations within this limit helps prevent complications such as gastric distension, which can lead to difficulties with ventilation and impair the functioning of the diaphragm.

Understanding this threshold is important for anesthesia practitioners as it directly impacts patient safety and comfort during procedures involving the use of LMAs. Proper technique and awareness of pressure limits enhance effective ventilation while minimizing adverse effects.