Effect Of Cytokines And Oxygenation During Selective Lobar Blockade In Thoracic Surgery

The application of one lung ventilation has been 50 years of history, the purpose of its application to avoid the contralateral lung from lung surgery,pollution, extended to facilitate the exposure of operative field, mainly for cardiac thoracic surgery and spinal surgery anesthesia.Advances in video thoracoscopic and minimally invasive surgery have increased demand for lung isolation techniques, with the use of a double-lumen endotracheal tube or an independent bronchial blocker in thoracic, cardiac or esophageal surgical patients.lt is estimated that 5-10% of patients who survive lung cancer resection (lobectomy or pneumonectomy) develop a second primary lung cancer within 5 years, and some of these patients will require further lung resection. One-lung ventilation for lung isolation can protect the lung from the contralateral side of the blood or secretions contaminated surgery, and provide a clear surgical field to facilitate the surgical operation, so that OLV have become commonly used in ventilation in thoracic surgery.However, this non-physiological method of ventilation will cause ventilation/perfusion ratio imbalance, increased intrapulmonary shunt, arterial partial pressure of oxygen reduction reactions.Selective lobar blockade (SLB) is a specific technique that allows one-lobe ventilation while the operated lobe is collapsed during thoracic surgery in patients with previous pulmonary resection requiring subsequent resection or in patients with limited pulmonary reserve resulting from severe pulmonary disease.Overseas studies have shown that Selective lobar blockade cannot only meet the needs surgery, but also increase high-risk patients undergoing thoracic surgery in the oxygenation.However, there is no literature reported on the impact of inflammatory cytokines during selective lobar blockade.In purpose of finding the effect of cytokines and oxygenation during selective lobar blockade in thoracic surgery,the author investigated the airway pressure,oxygenation index,the concentrations of cytokines in serum and bronchoalveolar lavage fluid and postoperative outcomes at the following times:15 min after two lung ventilation in the lateral decubitus position (T1);30 min (T2)and 60 min (T3) after TLC or SLB respectively; 15 min after recovering to two lung ventilation (T4),during selective lobar blockade or total lung collapse.Patients and MethodsThirty adult patients aged between 44yr and 65yr, ASAⅠorⅡ, with normal lung function undergoing elective esophagectomy for esophageal cancer and pulmonary resection for lung cancer were included in the study. Exclusion criteria were operation time of more than 6h or less than 1h, cardiac failure, chronic renal failure,altered liver function, or clinically relevant obstructive or restrictive lung diseases [vital capacity (VC) or forced expiratory volume in 1 s (FEV1)<65% of the predicted values], History of the long-term opioids and pulmonary or systemic infections. They were randomly assigned to the total lung collapse (TLC) group (n=15) or the selective lobar blockade (SLB) group (n=15).The study protocol was approved by the local Ethics Committee of the Nanfang hospital, and written informed consent was obtained from all patients one day before surgery. All patients were premedicated with oral midazolam 10mg and Atropine 0.5mg in the ward. In the operating theatre, a radial artery catheter was placed under local anaesthesia.TCI of propofol and remifentanil and fentanyl 3ug/kg were used to induce anaesthesia. Neuromuscular block was achieved with cisatracurium 0.2 mg kg-l,followed by endobronchial intubation with a 8.0mm internal diameter single-lumen tube in all patients. Then by the guidance of fiberoptic bronchoscope, a 9F coopdech endobronchial blocker was placed into the target lobe in the SLB group, whereas the blocker was placed into the mainstem bronchus in the TLC group. Arterial pressure was maintained within 20% of baseline values by administration of crystalloids and fentanyl. Increments of cisatracurium were given for need.All tracheal intubation were done by one well-skilled doctor.We used oxygen to avoid increased venous admixture from absorption atelectasis, and to maintain arterial haemoglobin saturation above 91%, measured by pulse oximetry. During two-lung ventilation (TLV), tidal volumes of 10 ml kg-1 were used with the ventilatory rate adjusted to maintain end-tidal PetCO2 at 35-40 mm Hg. After the beginning of SLB or TLC, tidal volumes were decreased to 5ml kg-1. The ratio of inspiratory to expiratory time was 1:2. With patient-controlled analgesia,all postoperative patients were sent to the ICU of Cardiothoracic Surgery.Hemodynamic index were measured and airaway pressure and arterial blood gas analysis done (ⅰ) after 15min of TLV with the patient in the lateral decubitus position; (ⅱ) after 30 min of SLB or TLC; and (ⅲ) after 60 min of SLB or TLC;(ⅲ) after 15 min of recovering to two lung ventilation.Bronchoalveolar lavage of the dependent ventilated lung was performed by passing a fibre optic bronchoscope through the endobronchial tube and wedging the tip into a segmental bronchus of the left-sided lower lobe or the right lower or middle lobes at TTLV15min and TreTLV15min. Different randomly chosen segments were subjected to BAL during each procedure. BAL was performed by sequential instillation of 37℃normal saline (10 ml portions, a total of 30 ml), and gentle aspiration. Lavage fluid was filtered through sterile gauze filters, collected on ice in siliconized containers and centrifuged immediately at 200g for 10 min. The supernatants were snap-frozen and kept at -80℃until analysis. At the same times,3ml of arterial blood samples were collected into nonpyrogenic,sterile falcon tubes. All samples from each patient were analysed in duplicate according to the instructions by the same investigator blinded to randomization. Serum TNF-a and IL-6 were measured using enzyme-linked immunosorbent assay (human TNF-a,IL-6 Immunoassay Quantikine[Jitai inc.,ExCELL,Italy],The lower detection limits for these kits are lOpg/ml.All data are reported as the mean±standard deviation(x±S).Test of homogeneity of variances was analyzed firstly,then analysis of one-way-anova was used to evaluate the basic status data such as body weight and age. Analysis of variance of repeated measure data was used to analyze the repeated measures data. The concentrations of IL-6 and TNF-a was analyzed by factorial analysis.SPSS 13.0 were used to analyze the data.P values of<0.05 were accepted as significant.Result:1.The Baseline data There Is no statistic significance between sex ratio,body weight,age and height(P>0.05).2.Haemodynaic variablesThere were no significant differences in haemodynaic variables among the groups (P>0.05). Comparison of patients ventilated with either SLB or TLC revealed significant differences in peak airway pressures(P<0.01). 3.Airway pressure and oxygenation indexSignificant trends were found toward a better improvement in PaO2 and a higher decrease in airway pressure with the SLB group compared to the TLC group at T2 T3 and T4 (P<0.05 or P<0.01).4.IL-6 and TNF-αconcentrations of the serum and BALF collected at T4 increased significantly comparing with those at T1 in both groups, but the concentrations of IL-6 and TNF-αin serum and BALF in the SLB group was lower than those in the TLC group at T4(P<0.01).5.Postoperative OutcomeThere are no severe complications happened in the two groups such as arrhythmia,ARDS,sepsis of shock,renal failure and so on. The case of postoperative pneumonia was lower in the SLB group. Although there was no difference between the two groups with regard to postoperative morbidity, intensive care duration of stay was significantly different between the two groups(P<0.01).Conclusion:1.Selective lobar blockade by Coopdech endobronchial blocker tube during esophagealsurgery provides a lower intraoperative intrapulmonary shunt and a better intraoperative arterial oxygenation.2.Compared with conventional one lung ventilation, Selective lobar blockade can provide more stable circulation and lower airway pressure.Furthermore, the new ventilating technique may reduce alveolar concentrations of TNF-αand of IL-6 in the ventilated lung and decease postoperative lung injury.