P-268
A PREDICTION MODEL OF PLEURAL DRAINAGE BASED ON ELECTRONIC CONTINUOUS FLUID MEASUREMENT

Objectives: We sought to verify whether the volume of pleural fluid drained in the first 6 hours after lobectomy is associated with the volume drained in the subsequent 24 hours by using an electronic continuous recording of pleural effusion.

Methods: A prospective analysis on 50 consecutive patients undergoing pulmonary lobectomy was performed. A single 28 Fr chest tube was connected to a regulating drainage system (8 cmH₂O) and featuring electronic continuous monitoring of airflow and fluid. Several baseline and surgical variables were tested for a possible association with total fluid drained from the 6th to 30th postoperative hour (EFF6-30) including the pleural fluid collected in the first 6 hours (ml). Linear regression and bootstrap analyses were used to derive a model to estimate the total effusion drained from the 6^th to the 30^th postoperative hour.

Results: The average effusion in the first 6 hours was 172 ml (range 0-449 ml). The trend of effusion recorded in the first 48 hours is shown. The following variables were associated with the effusion 6-30: effusion in the first 6 hours (P = 0.001, bootstrap 96%) and lower lobectomy (P = 0.05, bootstrap 51%). We created the following model: 187.5 ml + 7.6 ml x every 10 ml effusion first 6 hours + 95 ml in case of lower lobectomy. The model was validated in 1000 bootstrapped samples, showing no difference (P > 0.05) between predicted and observed effusion in 92% of samples. A hypothetical patient draining 100ml in the first 6 hours after lower lobectomy would have an expected effusion of 311 ml in the subsequent 24 hours.

Conclusions: By using an electronic continuous monitoring of pleural effusion, we found that the volume of fluid drained in the very first hours after lobectomy is associated with the effusion drained in the following 24 hours. The model can assist for planning early and safe removal of chest tube in case of absence of air leak.

Disclosure: K. Papagiannopoulos and A. Brunelli: Consultancy Medela