The volume threshold of 300 versus 100 ml/day for chest tube removal after pulmonary lobectomy: a meta-analysis

OBJECTIVES: In this meta-analysis, we conducted a pooled analysis of clinical studies comparing the efficacy of a volume threshold of 300 ml/day before removing a chest tube (CT) versus 100 ml/day after a lobectomy. METHODS: According to the recommendations of the Cochrane Collaboration, we established a rigorous study protocol. We performed a systematic electronic search of PubMed, Embase, Cochrane Library, Web of Science databases, CNKI, the Wanfang database, CBMdisc and Google Scholar to identify articles to include in our meta-analysis. A literature search was performed using relevant keywords. A meta-analysis was performed using RevMan (c) software. RESULTS: Five studies, published between 2014 and 2015, including 615 patients (314 patients who had the CT removed when daily drainage was <300 ml and 301 patients who had the CT removed when daily drainage was <100 ml) met the selection criteria. From the available data, the patients using the volume threshold of 300 ml/day had a significantly decreased duration of drainage [MD = -44.07; 95% confidence interval (Cl) -64.45 to -23.68; P <0.0001] and hospital stay after operation (MD = -2.25; 95% Cl -3.52 to -0.97; P = 0.0006) compared with patients using a volume threshold of 100 ml/day after a pulmonary lobectomy. However, no significant differences were observed in postoperative complications, such as pleural fluid reaccumulation [Odds ratio (OR)= 1.73; 95% Cl = 0.74-4.07; P= 0.211 and atelectasis (OR = 0.97; 95% Cl = 0.52-1.81; P=0.93). Thoracentesis rates after removing the CT also showed no significant difference (OR = 1.53; 95% Cl 0.55-4.22; P= 0.41). CONCLUSIONS: Our results showed that a higher volume threshold, up to 300 ml/day, is effective in reducing hospitalization times and duration of drainage in patients who undergo a lobectomy. Moreover, the volume threshold of 300 ml/day does not increase the occurrence of postoperative atelectasis, pleural fluid reaccumulation and thoracentesis rates. However, this review is limited by the methodological quality of the included trials, and additional studies according to the recommendations of Cochrane Library are appreciated.