[Prognostic value of pH and glucose in complicated parapneumonic pleural effusion]

Although the incidence of emphyema is increasing it continues to be a widely debated pathology in relation to its management. We analyzed the last 36 cases treated by our service in the last 2 years.

We retrospectively studied the last 36 cases of parapneum6nic pleural effusions that needed some type of treatment at our service from March, 2005 to May, 2007. For this we analyzed: average age, time of evolution before admission to hospital, time of evolution from admission to surgery, location of the pneumonia, echographic characteristics, value of the pH and glucose, the relation between the presence of echoes in the ultrasound scan with the value of the pH and of the glucose, the relation between value of the pH and glucose with the evolution, type of treatment and evolution. We used for the statistical study ANOVA's test and paired t-test and the student's T test.

The average age was 5.4 years (range 9 months-15 years). The average time of evolution prior to admission to the hospital was 5.6 days (range 0.5-20 days) and the average time from admission to surgery was 5.1 days (range 0-65 days). The pneumonia was multilobar in 38.2% of the cases, in low lobes in 52.9% (29.4% in the left lower lobe and 23.5% in the right lower lobe). Ultrasound scan was performed in 97.2% of the patients, being severely septated in 31.4% of the cases, clear liquid 25.7%, moderately septated 22.8% and minimally septated 17.1%. The pH was analyzed in 69.4% of the effusions, the average value being 7.16 (range 6.75-7.45). The glucose was analyzed in 61.1% of the effusions, the average value being 61.1 (range 1-123). Septated effusions in the ultrasound scans were related to the lowest values of pH and glucose (p = 0.0001 in both cases). When we analyzed the relationship between clinical evolution and the pH we observed that a lower value of pH was related to a worse evolution, finding that pH values below 7 are related to a bad evolution (p = 0.001). The same results were found when we analyzed the relationship between the evolution and glucose (p < 0.005).

The pH and the glucose in complicated parapneumonic pleural effusion have a pronostic value for evolution, regardless of what treatment was used. We found that pH values below 7 are related to a bad evolution.