Acute lung injury represents the most probable organ injury in the context of severe acute pancreatitis, with the exception of the pancreas, which is primarily distinguished by respiratory insufficiency, manifested as shortness of breath, cyanosis, and diminished lung compliance. Nevertheless, the precise pathogenesis remains incompletely elucidated. Despite the administration of protective measures, the quality of life of patients with severe acute pancreatitis complicated by acute lung injury remains adversely affected.

To systematically evaluate the risk factors of severe acute pancreatitis complicated with acute lung injury.

Computer searches were conducted on CNKI, Wanfang database, VIP, PubMed, Web of Science and EBSCO databases to search relevant studies on the risk factors of severe acute pancreatitis complicated with lung injury from the establishment of the database to October 2023. Two researchers independently screened literature, extracted data, evaluated literature quality and evidence level, and conducted meta-analysis using RevMan 5.3 software. Begg's test in Stata17.0 was used for publication bias analysis.

A total of 10 studies were included, all of which were case-control studies, including 1 053 patients with severe acute pancreatitis. The results of meta-analysis showed that increased age (SMD=0.58, 95%CI=0.03-1.14, P=0.04), elevated fasting blood glucose (SMD=0.45, 95%CI=0.27-0.64, P<0.000 01), and an elevated respiratory rate (>30 breaths/min) (OR=6.18, 95%CI=3.20-11.94, P<0.000 01), the occurrence of fever (OR=12.92, 95%CI=4.41-37.84, P<0.000 01), the occurrence of pleural effusion (OR=7.19, 95%CI=3.25-15.91, P<0.000 01), decreased albumin (SMD=-0.77, 95%CI=-0.98 to -0.56, P<0.000 01), combined with obesity (OR=3.11, 95%CI=1.94-4.98, P<0.000 01), decreased calcium ion (SMD=-0.63, 95%CI=-0.85 to -0.42, P<0.000 01), combined with acidosis (OR=2.15, 95%CI=1.03-4.49, P=0.04), elevated C-reactive protein (SMD=0.79, 95%CI=0.56-1.03, P<0.000 01), decreased hemoglobin (SMD=-0.77, 95%CI=-1.10 to -0.43, P<0.000 01), elevated blood amylase (SMD=0.21, 95%CI=0.01-0.42, P=0.04), increased urinary amylase (SMD=0.40, 95%CI=0.03-0.77, P=0.03), elevated Ranson score (SMD=0.87, 95%CI=0.66-1.08, P<0.000 01), a rise in APACHE Ⅱ score (SMD=0.77, 95%CI=0.58-0.96, P<0.000 01), increased CT severity index score (SMD=0.39, 95%CI=0.19-0.59, P<0.000 01), elevated BISAP (SMD=0.62, 95%CI=0.37-0.88, P<0.000 01), severe acute pancreatitis with hyperlipidemia (OR=1.68, 95%CI=1.05-2.67, P=0.03), combined with SIRS (OR=9.57, 95%CI=4.03-22.72, P<0.000 01), number of organ injury (≥2) (OR=6.94, 95%CI=3.34-12.59, P<0.000 01), the occurrence of infection (OR=4.59, 95%CI=2.42-8.71, P<0.000 01) were risk factors for severe acute pancreatitis complicated with acute lung injury. The results of the publication bias analysis demonstrated that no significant publication bias was observed for the 14 factors (age, obesity, glucose, albumin, calcium ions, C-reactive protein, serum amylase, respiratory rate, Ranson score, APACHE Ⅱ score, CT severity index score, BISAP, hyperlipidemicity and pleural effusion) for which the analyses were conducted (P>0.05). The GRADE evidence evaluation demonstrated that a total of 11 risk factors (age, respiratory rate, pleural effusion, obesity, hemoglobin, serum amylase, urinary amylase, Ranson score, BISAP, hyperlipidemicity and organ damage) exhibited moderate quality, while 10 (fasting blood glucose, fever, albumin, calcium ions, acidosis, C-reactive protein, APACHE Ⅱ score, CT severity Index score, SIRS and infection) demonstrated low quality.

Age increase, fasting blood glucose, amylase, C-reactive protein, urinary amylase increase, albumin, hemoglobin, calcium ion concentration decrease, respiratory rate (>30 breaths/min), Ranson score, APACHE Ⅱ score, CT severity index score, BISAP score high, SAP subtype - hyperlipidemia, fever, acidosis, obesity, pleural effusion, SIRS, organ involvement (≥2) and infection were the risk factors for ALI in SAP patients. In the future, it is necessary to carry out further high-level research to prove the above research results.