The effects of thoracic epidural analgesia on oxygenation and pulmonary shunt fraction during one-lung ventilation: an meta-analysis

Impact of pharmacological interventions on intrapulmonary shunt during one-lung ventilation in adult thoracic surgery: a systematic review and component network meta-analysis

BACKGROUND

Intrapulmonary shunt is a major determinant of oxygenation in thoracic surgery under one-lung ventilation. We reviewed the effects of available treatments on shunt, Pao₂/FiO₂ and haemodynamics through systematic review and network meta-analysis.

METHODS

Online databases were searched for RCTs comparing pharmacological interventions and intrapulmonary shunt in thoracic surgery under one-lung ventilation up to March 30, 2022. Random-effects (component) network meta-analysis compared 24 treatments and 19 treatment components. The Confidence in Network Meta-Analysis (CINeMA) framework assessed evidence certainty. The primary outcome was intrapulmonary shunt fraction during one-lung ventilation.

RESULTS

A total of 55 RCTs were eligible for systematic review (2788 participants). The addition of N₂O (mean difference [MD]=-15%; 95% confidence interval [CI], -25 to -5; P=0.003) or almitrine (MD=-13%; 95% CI, -20 to -6; P<0.001) to propofol anaesthesia were efficient at decreasing shunt. Combined epidural anaesthesia (MD=3%; 95% CI, 1-5; P=0.005), sevoflurane (MD=5%; 95% CI, 2-8; P<0.001), isoflurane (MD=6%; 95% CI, 4-9; P<0.001), and desflurane (MD=9%; 95% CI, 4-14; P=0.001) increased shunt vs propofol. Almitrine (MD=147 mm Hg; 95% CI, 58-236; P=0.001), dopexamine (MD=88 mm Hg; 95% CI, 4-171; P=0.039), and iloprost (MD=81 mm Hg; 95% CI, 4-158; P=0.038) improved Pao₂/FiO₂. Certainty of evidence ranged from very low to moderate.

CONCLUSIONS

Adding N₂O or almitrine to propofol anaesthesia reduced intrapulmonary shunt during one-lung ventilation. Halogenated anaesthetics increased shunt in comparison with propofol. The effects of N₂O, iloprost, and dexmedetomidine should be investigated in future research. N₂O results constitute a research hypothesis currently not backed by any direct evidence. The clinical availability of almitrine is limited.

SYSTEMATIC REVIEW PROTOCOL

PROSPERO CRD42022310313.

Effects of Thoracic Epidural Anesthesia on Systemic and Local Inflammatory Responses in Patients Undergoing Lung Cancer Surgery: A Randomized Controlled Trial

OBJECTIVE

Inflammatory responses play major roles in the development of acute lung injury following lung cancer surgery. The authors tested the hypothesis that thoracic epidural anesthesia (TEA) during surgery could attenuate both systemic and local inflammatory cytokine productions in patients undergoing lung cancer surgery.

DESIGN

A prospective randomized controlled trial.

SETTING

At Keio University Hospital, Tokyo, Japan.

PARTICIPANTS

Patients scheduled for lung cancer surgery.

INTERVENTIONS

Sixty patients were randomly allocated into two groups (n = 30 each group): the epidural group (group E), in which anesthesia was maintained with propofol, fentanyl, rocuronium, and epidural anesthesia with 0.25% levobupivacaine; or the remifentanil group (group R), in which a remifentanil infusion was used as a potent analgesia instead of epidural anesthesia.

MEASUREMENTS AND MAIN RESULTS

The lung epithelial lining fluid (ELF) and blood sampling were collected prior to one-lung ventilation (OLV) initiation (T1) and at 30 minutes after the end of OLV (T2). The concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-10 in the ELF at T2 were increased significantly compared with those at T1 in both groups. The ELF concentration of IL-6 in group E was significantly lower than that in group R at T2 (median [interquartile range]: 39.7 [13.8-80.2] versus 76.1 [44.9-138.2], p = 0.008). Plasma IL-6 concentrations at T2, which increased in comparison to that at T1, were not significantly different between the two groups. The plasma concentrations of TNF-α did not change in both groups.

CONCLUSIONS

This randomized clinical trial suggested that TEA could attenuate local inflammatory responses in the lungs during lung cancer surgery.

Effects of volume-controlled ventilation vs. pressure-controlled ventilation on respiratory function and inflammatory factors in patients undergoing video-assisted thoracoscopic radical resection of pulmonary carcinoma

Background

The best ventilation approach for patients undergoing video-assisted thoracic surgery (ATS) for pulmonary carcinoma remains undefined. This study aimed to assess hemodynamics, airway pressure, arterial blood gas, and inflammatory factors in patients undergoing VATS for pulmonary carcinoma under volume-controlled ventilation (VCV) or pressure-controlled ventilation (PCV).

Methods

This was a prospective study of 60 patients with pulmonary carcinoma treated at a tertiary center in 2015-2016. The subjects were randomized to the VCV or PCV group after anesthesia and total lung ventilation (TLV). Hemodynamics and blood gas parameters were compared between the two groups pre-OLV (one-lung ventilation) (T1) and after 30 (T2), 60 (T3), and 120 (T4) minutes of OLV. Radial artery blood was collected to measure interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-α levels.

Results

Hemodynamic and blood gas parameters were similar between the two groups (all P>0.05). During OLV, airway resistance (RAW) was significantly lower in the PCV group compared with the VCV group at T2 (26.0±3.8 vs. 29.9±7.3 cmH₂O/L/s), T3 (26.0±3.7 vs. 30.2±7.7 cmH₂O/L/s), and T4 (25.8±4.1 vs. 29.6±6.7 cmH₂O/L/s). Similar trends were found for peak pressure (Ppeak) and plateau pressure (Pplat). Mean pressure (Pmean) was similar between the two groups. Compared with the PCV group, TNF-α and IL-6 levels in the VCV group were significantly increased (all P<0.05). The levels of the anti-inflammatory mediator IL-10 were higher in the PCV group compared with the VCV group.

Conclusions

PCV for OLV during radical resection of pulmonary carcinoma by VATS could reduce Ppeak and downregulate pro-inflammatory factors, likely decreasing airway injury.

Anesthetic management of off-pump simultaneous coronary artery bypass grafting and lobectomy: Case report and literature review

RATIONALE

Survey data show approximately 10% patients with lung cancer may present concomitant coronary heart disease. Simultaneous surgery is a challenge for anesthetist. We review our experience in the anesthesia with 5 patients who required simultaneous off-pump coronary artery bypass grafting (OPCABG) and pulmonary resection for lung cancer.

PATIENT CONCERNS

Between 2014 and 2016, 5 patients with ASA (American Society of Anesthesiologists) grade II or III, underwent combined OPCABG and lung resection in the first Affiliated Hospital, Zhejiang University School of Medicine.

DIAGNOSES

All five patients were diagnosed with coronary heart disease and peripheral pulmonary carcinoma INTERVENTIONS:: Five patients received general anesthesia with double-lumen endobronchial tube for lung separation. The anesthetics were used, which caused slight hemodynamic fluctuations during induction of anesthesia; while during the maintenance of anesthesia, supplemented by Dexmedetomidine, the drug doses were titrated according to the depth of anesthesia. Guided by cardiac index (CI), stroke volume variation (SVV) and oxygen delivery (DO2), different strategies were taken at the different stage of surgery, during lung resection, SVV was kept about 13% to 15%, and less than 10% during OPCABG.

OUTCOMES

Five patients were transferred to intensive care unit (ICU) with intubation after surgery, duration of ventilation was 10 to 18 hours, and length of ICU stay and hospital stay were 1.8 to 2.5 ds and 11 to 16 ds, respectively. All of patients were discharged with not any perioperative complication.

LESSONS

In summary, anesthetists should focus on the maintenance of the balance between oxygen supply and demanding, which was achieved by close monitoring, titration of anesthetics and goal-directed fluid therapy during surgical procedures.

One-lung Ventilation for Thoracic Surgery: Current Perspectives

One-lung ventilation (OLV) is an anesthesiological technique that is increasingly being used beyond thoracic surgery. This requires specific skills and knowledge about airway management, maintenance of gas exchange and prevention of acute lung injury. Sometimes maintaining adequate gas exchange and minimizing acute lung injury may be opposing processes. Parameters validated for OLV titration still have not been found, but a multimodal approach based on low tidal volume, end-expiratory pressure application and alveolar recruitment maneuvers is considered the best way to ensure protective ventilation and reduce lung damage. The purpose of this review is to analyze all these factors using the latest scientific evidence and the opinions of the most influential authors.