Ultrasound Assessment of Aeration Changes After Lung Resection: a Pilot Study

Brief Summary

Detailed Description

Postoperative pulmonary complications (PPC) are common after lung resection surgery, with an incidence that ranges between 11-32%. As PPC are associated with worse outcomes, many studies aim to find predictors that identify high risk patients and prompt specific interventions and/or monitoring and hence, improve outcomes. PPC result from lung injury inherent to lung resection surgery. Lung aeration changes seen with lung ultrasound (LUS) could detect lung injury and thus, identify patients at high risk of PPC. The underlying mechanisms of lung injury are different in the dependent and non-dependent lung; oxidative stress in both lungs, lung injury associated with one-lung ventilation in the dependent lung and ischemia/reperfusion or surgical manipulation in the non-dependent lung. LUS evaluates the operated and non-operated lung separately and so it can be valuable in understanding the characteristics and intensity of lung injury in each lung specifically. This is a prospective, single-centre, observational study in which 28 consecutive participants with non-small cell lung cancer scheduled for lobectomy will be recruited. Participants will be divided in two groups depending on the surgical approach. First group will be lobectomy via thoracotomy. Second group will be lobectomy via VATS. Participants will be recruited consecutively until there are 14 patients in each group. LUS will be performed in each participant's dependent and non-dependent lung at three predefined time points: before surgery, after extubation and 24 h after surgery. Each hemithorax will be divided into 6 areas: anterior, lateral and posterior, separated by the anterior and posterior axillary lines, each divided into upper and lower zones. For each echographic examination, cineloops of the most pathological findings in each area will be stored and analysed offline by two independent and blinded anesthesiologists. From these, a semiquantitative score, the modified lung ultrasound score (mLUSS), will be calculated for each hemithorax to assess lung aeration at each time point. The level of agreement for mLUSS will be tested. At the same predefined time points blood plasma samples will be collected, flash-frozen and stored in order to measure levels of the inflammatory mediators IL-6, IL-10 and TNFα. The invertigators hypothesise that LUS can detect lung injury after lung resection surgery. The primary objective of the study is to assess changes in lung aeration after lung resection with mLUSS. Secondary objectives are, first, to describe LUS findings after lung resection surgery, second, to assess the ability of mLUSS to detect oxygenation changes after lung resection and third, to compare the behaviour of inflammatory mediators in plasma with mLUSS changes.

Primary Outcomes

Secondary Outcomes

• Changes in plasma cytokine IL-10 after lung resection(preoperative vs immediate postoperative vs 24 hours after surgery)
• Changes in blood bone natriuretic peptide (BNP) after lung resection.(preoperative vs immediate postoperative vs 24 hours after surgery)
• LUS findings in the dependent and non-dependent lung(preoperative vs immediate postoperative period vs 24 hours after surgery)
• Changes in plasma TNFα after lung resection(preoperative vs immediate postoperative vs 24 hours after surgery)
• Changes in oxygenation (PAFI) after lung resection(preoperative vs immediate postoperative vs 24 hours after surgery)
• Changes in plasma cytokine IL-6 after lung resection(preoperative vs immediate postoperative vs 24 hours after surgery)