Effect of postoperative hemoglobin variation on major cardiopulmonary complications in high-risk patients undergoing anatomical lung resections

Background:

Recent evidences show that permissive anemia strategies are safe in different surgical settings. For oncological patients, blood transfusions are not only related to in-hospital complications, but also to worst long-term prognosis. However, the effects of hemoglobin variation could have a negative impact in high-risk patients. We investigated the combined effect of postoperative hemoglobin concentration and cardiac risk status on major cardiopulmonary complications after anatomical lung resections.

Material and method:

We retrospectively analyzed the records, collected in a prospective clinical database, of 124 consecutive patients undergoing anatomical lung resections at our institution (February 2017-December 2018).

Univariate and multivariate logistic regression analysis were used to test association between patients and surgical variables, and cardio-pulmonary complications according to the European Society of Thoracic Surgeons definitions. Hemoglobin levels were displayed as pre-operative concentration, nadir level before onset of complications and delta hemoglobin. Cardiac risk was stratified according to the Thoracic Revised Cardiac Risk Index (ThRCRI).

Result:

Major cardiopulmonary complications occurred in 23 patients (18.5%). In the fully adjusted multivariate model, higher values of delta hemoglobin increase the risk of complications (odds ratio 1.05, p = 0.009), combined with the higher ThRCRI classes (classes A-B vs. C-D: odds ratio 0.10, p < 0.001). Seven patients (5.6%) received at least 1 blood transfusion, but interaction terms with transfusion were not statistically significant. Based on Youden ROC curve analysis, delta hemoglobin of 29 g/l was found to be the best cut-off value in predicting complications.

Conclusion:

In our series, postoperative decrease in hemoglobin levels, rather than pre-operative anemia and blood transfusions, increases the risk of major cardiopulmonary complications, particularly in patients with higher cardiac risk. At first instance, all possible strategies to reduce blood loss should be used. Moreover, restrictive transfusion strategies should be carefully applied in patients undergoing lung resections and balanced according to surgical indication and individual clinical status.