Clinical application of esophageal manometry: how I do it

 

Clinical application of esophageal manometry: how I do it

 

by Elias Baedorf Kassis and Daniel Talmor 

 

Critical Care volume 25, Article number: 6 (2021) 

 

Our group uses esophageal manometry routinely to personalize mechanical ventilation in patients with acute respiratory distress syndrome (ARDS) [1, 2]. Esophageal pressures (Pes) allow for differentiation of chest wall, lung and respiratory system mechanics, and we use this for PEEP titration [1, 2], monitoring of parenchymal lung stress, limiting peak end-inspiratory transpulmonary pressures and monitoring for ventilator synchrony [3, 4].

We find that esophageal manometry is straightforward in the majority of patients although proper training and application are important. The initial step is to assure correct placement with insertion of stand-alone catheters or feeding tubes with integrated esophageal balloons which are similar to routine gastric tubes. Typical depth of insertion ranges from 33 to 40 cm, depending on body size and we assure proper placement through functional bedside assessment. First, we look for the presence of cardiac oscillations to assure correct position posterior to the heart. If absent, this suggests the balloon is too deep or shallow and we incrementally adjust while monitoring for these oscillations. Next we perform expiratory breath holds, with changes in Pes, airway (Pao) and transpulmonary pressure (PL = Pao − Pes) monitored during gentle chest pushes. Proper position is confirmed when Pes and Pao increase in equal measure, with no change in the calculated PL. If Pao increases more Pes, this suggests that position is too deep and the balloon is adjusted incrementally with repeat chest pushes. This may be confirmed with gentle abdominal pushes (with Pes increasing more than Pao). (Table 1)…