In this study we found that 2/100 Hz TEAS reduced postoperative pulmonary complications in VATS lobectomy patients during prolonged one lung ventilation.Three acupoints located in the lung meridians on the operative side were selected (one of them was used as a substitute for the previous acupoint when it could not be used due to patient and surgical reasons). Those selected acupoints are the most recognized and widely used among the acupoints supported by the current literature, and are used to improve lung oxygenation and reduce lung inflammation
Dead space,shunt fraction and PaO2/FiO2 reflecting intraoperative oxygenation was measured at T2,T3,and T4.Under baseline conditions(T2),the above indicators were no difference between two groups.With the prolonged operation time,TEAS group showed obvious advantages over Control group under the stimulation of Hegu and Lieque points.The difference of dead-space and shuntfraction was significant(P < 0.001).
Previous studies have shown that TEAS can improve patients' oxygen saturation during perioperative period,and reduce the hypoxia in PACU[10, 11].Our study proved the previous paper with respiratory mechanism Qs/Qt and dead space,which were more sensitive and reliable in reflecting pulmonary oxygenation.In a word,due to the reduction of oxygen exchange area,V/Q imbalance and hypoxic of pulmonary vasoconstriction,oxygenation gradually decreases during one lung ventilation. The mechanism of TEAS’ positive effect still not clear, some basic research suggests the stimulation of A α and A β fibers,which could dilated bronchus,redistribute lung blood flow and gas,improve lung function and protect the lung from collapse caused hypoxia.
Inflammatory markers were less detected in the TEAS group, it was found that the NLR of TEAS group and Control group was statistically different at T4(P = 0.001) and T5(P = 0.001).While PLR was a difference at T5(P = 0.015). Perioperative PLR and NLR are simple, cheap and widely available markers, which can reflect systemic inflammatory status.There were few prospective studies on the relationship between perioperative PLR or NLR and PPCs, which is the starting point for us to select these two indicators[12, 13, 14].The increases of inflammatory markers correlated with occurrence of complications. After TEAS treatment, the incidence of PPCs was notablely reduced, and the patients with lower PLR or NLR during and after surgery had better postoperative recovery.
Binary logistic regression was performed on the severity indicators of the patients at the above moments and postoperative pulmonary complications(Table 5), they were meaningful in predicting postoperative lung complications,which may attribute to the anti-inflammatory properties of TEAS.
Table 5
Binary logistic regression results.OR: odds ratio;
Inflamation markers | OR | | P value |
NLR(T5) | | 1.140(1.068–1.825) | 0.015 |
PLR(T5) | | 1.014(1.006–1.021) | 0.001 |
The use of double-lumen tubes and the high incidence of airflow obstruction in thoracic surgery led airway resistance during the procedure to be greater than in other types of surgery[15].Our previous study has already demonstrated systemic lung injury form inflammatory response syndrome can be alleviated by TEAS in septic mice model, it has been confirmed that Protein kinase C interaction protein 1 (PICK1) is a protein with both PDZ (PSD-95 / Dlg / ZO1) and BAR (Bin / amphiphysin / Rvs) domains, which can protect acute lung injury(through PICK1-CaMK-II Link). Whether PPCs caused by inflammatory reaction acts on this pathway needs further study.
In this clinical research,varies of inflammatory markers PLR and NLR associated with incidence of PPCs proved the previous hypothesis.Both PLR and NLR are simply, inexpensively and widely available markers to reflect systemic inflammation status[16].Our study showed that intraoperative PLR and NLR have a positive correlation with the PPCs particularly respiratory infection and Pleural effusion in patients undergoing VATS lobectomy.
NLR increases when neutrophil dependence inflammatory response was enhanced or lymphocyte meditated immune response was reduced,which may weaken antibacterial ability and toleration of surgery stress.As immune cells, platelets can initiate and accelerate many vascular inflammatory conditions [8, 17, 18].
We aim to provide a acceptable, cheaper, more available indicator for clinicians to efficiently estimate the incident of surgical treatment of VATS patients. The peripheral blood count test is routinely performed in all patients. The intraoperative PLR and NLR is easy to obtain and come with less costs for patients attempt to have VATS lobectomy.
Our study has several limitations. First, the duration of OLV different from all patients, which associate with PPCs. Second, to identify the PPCs is complicate especially when two or more PPCs happened in one patients, which can explain high incidence of PPCs in our study. Three, preoperative pulmonary functionwas not included in preoperative analysis, randomization, sample size and ARISCAT score may offset its impact,to make the results more applicable to clinical practice. Furthermore, the uncertain of the tumour Benign and Malig before surgery increased the inhomogeneity of our study population.