Preoperative serum lactate dehydrogenase level as a predictor of major complications following thoracoscopic lobectomy: a propensity-adjusted analysis.

OBJECTIVES: Despite the positive effects of a thoracoscopic approach on improving postoperative outcomes, the risk of major complications following thoracoscopic lobectomy is not negligible. We sought to assess the usefulness of the preoperative determination of serum biomarkers to refine risk stratification in this patient population.

METHODS: From 2009 to 2017, 626 patients (285 women, 341 men; median age: 67 years) underwent thoracoscopic lobectomy or anatomical segmentectomy for confirmed or suspected early-stage lung cancer or metastasis at our institution. Preoperative serum biomarkers, including albumin, C-reactive protein, haemoglobin and lactate dehydrogenase (LDH), were examined as predictors of postoperative cardiopulmonary complications using logistic regression analyses followed by causal inference.

RESULTS: The 90-day mortality, cardiopulmonary complication and overall morbidity rates were 1.0%, 13.1% and 18.1%, respectively. Although serum albumin, C-reactive protein and haemoglobin were not associated with cardiopulmonary complications in regression analyses, preoperative serum LDH level emerged as an independent morbidity predictor (odds ratio 1.008, 95% confidence interval 1.002-1.013; P = 0.006). The causal inference using the covariate balancing generalized propensity score methodology demonstrated similar results and an approximately positive linear relationship between the odds of cardiopulmonary complications and preoperative serum LDH level. For every 100 U/l increase in preoperative serum LDH, a 2-fold increase in the odds of cardiopulmonary complications was observed.

CONCLUSIONS: Our results suggest that the preoperative serum LDH level is an independent predictor of 90-day cardiopulmonary complications following thoracoscopic lobectomy or segmentectomy, even in properly selected patients. Therefore, we recommend incorporating early serum LDH measurements as a readily available method into the risk assessment process prior to major lung resection.