Risk factors, pathogenesis, and botanical drugs interventions for postoperative pulmonary complications after cardiothoracic surgery: a narrative review.

BACKGROUND AND

OBJECTIVE

Postoperative pulmonary complications (PPCs) are common and severe after cardiothoracic surgery, leading to prolonged hospital stays, increased medical burden, and elevated mortality. Driven by patient-related, surgery-related, and perioperative factors, PPCs are characterized by a pathophysiology involving inflammation, oxidative stress, alveolar injury, and airway obstruction. This review aims to systematically summarize PPCs' risk factors, pathogenesis, and the role of botanical drugs, providing a scientific basis for clinical decision-making.

METHODS

Relevant literature published from 2010 to 2025 were searched in PubMed, Embase, Web of Science, and Cochrane Library using keywords such as "Postoperative pulmonary complications (PPCs)", "Botanical drugs", "Pathogenesis", "Risk factors", and "Cardiothoracic surgery". Eligible English studies [randomized controlled trials (RCTs), cohort studies, systematic reviews, etc.] were included, with low-quality studies and those unrelated to cardiothoracic surgery excluded. Quality assessment was performed using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2), Newcastle-Ottawa Scale (NOS), and Risk of Bias Tool 2.0 (RoB 2), and 55 studies were finally included for data extraction and synthesis.

KEY CONTENT AND FINDINGS: Key PPCs risk factors include patient-related [age ≥65 years, chronic obstructive pulmonary disease (COPD), smoking history], surgery-related [extensive resection, prolonged one-lung ventilation (OLV)], and perioperative factors (inadequate analgesia, prolonged bed rest). Core pathophysiological mechanisms involve Toll-like receptors (TLRs) and the nuclear factor-κB (NF-κB) pathway-mediated inflammation, excessive reactive oxygen species (ROS)-induced oxidative stress, alveolar type II cell dysfunction, and airway obstruction. Botanical drugs (e.g., Huanglian Jiedu Decoction, andrographolide, and Salvia miltiorrhiza extract) exert protective effects against PPCs by modulating inflammatory pathways, scavenging free radicals, and preserving the pulmonary barrier; however, relevant studies are limited by small sample sizes and single-center study designs.

CONCLUSIONS

PPCs' pathogenesis is complex, and clarifying their risk factors and mechanisms provides clinical intervention targets. Botanical drugs, with multi-target effects, serve as valuable supplements to modern medicine for PPCs management. Future research should focus on large-sample, multicenter RCTs to validate botanical drugs' efficacy and safety, and explore integrated Chinese-Western medicine strategies to optimize postoperative recovery.