MATERIALS & METHODS

This systematic review follows the 2020 updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline.8

Literature search

We conducted a systematic literature search of studies investigating the effectiveness of routine chest X-rays after drain removal in patients undergoing cardiothoracic surgery in Pubmed, Medline via Ovid, Cochrane central register of control trials (CENTRAL) and ClinicalTrials.gov. There was no limit on the publication year of the studies, and the last search was performed on 17 April 2022. The keywords used in combination with Boolean operators include “cardiac surgery”, “thoracic surgery”, “cardiothoracic surgery”, “chest drain removal”, “chest tube removal”, “chest X-ray” and “chest radiograph”. The references of the included studies and relevant reviews are also manually screened for identifying potentially eligible studies.

Inclusion and exclusion criteria

Original research studies reporting the incidence of pneumothorax and chest X-ray findings after the chest drain removal in both adult and paediatric patients undergoing cardiac and thoracic surgery procedures were included. The exclusion criteria included case reports, case series, reviews and studies on chest X-rays after drain removal on the trauma patients exclusively.

Study screening, data extraction and outcome measures

Two authors (KPPH, KEH) independently reviewed the included studies and performed data extraction. Disagreements between the authors were resolved by consensus or by escalating to another author (MST). The following set of data was extracted: (i) study characteristics including study design, (ii) patient population characteristics, (iii) incidence of pneumothorax after removal of drain, (iv) clinical signs and symptoms following the removal of chest drain, and (v) re-intervention (re-insertion) of chest drain. The primary outcome measure is the incidence of pneumothorax, whereas, the secondary outcomes include the need for re-intervention following the removal of the chest drain, and signs and symptoms after chest drain removal.

Quality assessment

The quality of the included studies was independently assessed by two authors (KPPH, KST) using the Methodological Index for Nonrandomized Studies (MINORS).9All included studies are moderate-quality studies with a global score ranging from 8-12 out of 16.