The Effect of Suction on Chest Tube Progression in Children with Parapneumonic Effusions

BACKGROUND: Suction is frequently used on chest tubes draining parapneumonic effusions, but its impact on clinical progression remains uncertain. While suction may expedite drainage, it might also delay healing by perpetuating leaks or pneumothorax. This study used Markov modeling to assess the effect of suction on transitions between clinically meaningful states. METHODS: With REB approval, we reviewed the charts of 81 children who had 95 chest tubes placed for parapneumonic effusions between 2014 and 2024. Necrotizing pneumonia patients were excluded. Six clinical states were categorized as: Drainage (>2 ml/kg/day), Dry (≤2 ml/kg/day), Leak (bubbling), Pneumothorax, Resolved and Video-Assisted Thoracoscopic Surgery. Suction was recorded as either absent or present. A semi-Markov model, adjusting for time spent in each state, was used to evaluate the impact of suction on state transitions. Hazard ratios (HR) and p-values were estimated. RESULTS: Suction decreased the rate of moving from the Dry state to the Resolved state (HR=0.40, p=0.002), suggesting that suction was associated with a delay in clinical improvement once the effusion had cleared. Suction did not affect the likelihood of moving from other clinically important states toward resolution. CONCLUSION: While suction is believed to promote faster clearance of parapneumonic effusions, it may slow recovery after the effusion has been evacuated. These findings support the early use of suction with discontinuation once the effusion resolves. Further prospective studies are warranted to refine suction strategies in pediatric parapneumonic effusions.