Influence of Ventilation Parameters on Intraabdominal Pressure

Intraabdominal pressure monitoring is not routinely performed because the procedure assumes some invasiveness and, like other invasive procedures, it needs to have a clear indication to be performed. The causes of IAH are various. Mechanically ventilated patients have numerous parameters set in order to be optimally ventilated and it is important to identify the ones with the biggest interference in abdominal pressure. Although it was stated that mechanical ventilation is a potential factor of high intraabdominal pressure the set parameters which may lead to this diagnostic are not clearly named.

To evaluate the relation between intraabdominal pressure and ventilator parameters in patients with mechanical ventilation and to determine the correlation between intraabdominal pressure and body mass index.

This is an observational study which enrolled 16 invasive ventilated patients from which we obtained 61 record sheets. The following parameters were recorded twice daily: ventilator parameters, intraabdominal pressure, SpO2, Partial Oxygen pressure of arterial blood. We calculated the Body Mass Index (BMI) for each patient and the volume tidal/body weight ratio for every recorded data point.

We observed a significant correlation between intraabdominal pressure (IAP) and the value of PEEP (p=0.0006). A significant statistical correlation was noted regarding the tidal volumes used for patient ventilation. The mean tidal volume was 5.18 ml/kg. Another significant correlation was noted between IAP and tidal volume per kilogram (p=0.0022). A positive correlation was found between BMI and IAP (p=0.0049), and another one related to the age of the enrolled patients. (p=0.0045).

The use of positive end-expiratory pressures and high tidal volumes during mechanical ventilation may lead to the elevation of intraabdominal pressure, a possible way of reducing this risk would be using low values of PEEP and also low volumes for the setting of ventilation parameters. There is a close positive correlation between the intraabdominal pressure levels and body mass index.