Tidal swings of endotracheal tube cuff pressure during pressure support ventilation: A CARE-compliant case report.

RATIONALE: During assisted mechanical ventilation, such as pressure support ventilation (PSV), it is crucial to align the ventilator support with the patient's inspiratory effort. Therefore, continuous monitoring of effort at the bedside is essential. PATIENT CONCERNS: In this report, we present a 43-year-old woman undergoing pressure support ventilation via an oral endotracheal intubation (7.5-mm I.D., depth of 22 cm from central incisors, and cuff inflated to a pressure of 30 cmH2O). DIAGNOSES: Acute hypoxemic respiratory failure secondary to pneumonia. INTERVENTIONS: Pressure support ventilation was initiated to evaluate weaning readiness, and esophageal pressure (PES) monitoring was established to assess inspiratory effort. Endotracheal tube cuff pressure (PCUFF) was monitored. During the inspiratory phase of pressure support ventilation, negative tidal swings were noticed in the PCUFF tracing, whose shapes were consistent with those of PES. A downward pressure support titration was performed from 15 cmH2O to 5 cmH2O in 2 cmH2O increments. PES and PCUFF were simultaneously recorded. OUTCOMES: As the pressure support decreased, the negative tidal swing of PES increased markedly. At pressure support of 13 cmH2O and 15 cmH2O, the tidal swing of PCUFF exhibited a plain or slightly positive shape. However, as the pressure support further decreased to levels below 11 cmH2O, the tidal swing of PCUFF changed to a negative shape, and the magnitude increased markedly. The tidal swings of PCUFF and PES were closely correlated across different pressure support levels. Chest radiography confirmed that the endotracheal tube cuff position was below the thoracic inlet and within the thoracic cage. LESSONS: This case illustrates the potential application of PCUFF in assessing inspiratory effort during pressure support ventilation. However, due to the preliminary nature of this single observation, further study in a large cohort is warranted.