Increased Interleukin-8 in Epithelial Lining Fluid of Collapsed Lungs During One-Lung Ventilation for Thoracotomy

Effects of laryngeal mask ventilation on postoperative atelectasis in children undergoing day surgery: a randomized controlled trial

BACKGROUND

To compare the effects of laryngeal mask mechanical ventilation and preserved spontaneous breathing on postoperative atelectasis in children undergoing day surgery.

METHODS

Children aged 3-7 who underwent elective day surgery were randomly divided into a spontaneous breathing group (n = 23) and a mechanical ventilation group (n = 23). All children enrolled in this trial used the same anesthesia induction protocol, the incidence and severity of atelectasis before induction and after operation were collected. In addition, the baseline data, intraoperative vital signs, ventilator parameters and whether there were complications such as reflux and aspiration were also collected. SPSS was used to calculate whether there was a statistical difference between these indicators.

RESULTS

The incidence of atelectasis in the spontaneous breathing group was 91.30%, and 39.13% in the mechanical ventilation group, and the difference was statistically significant (P = 0.001). There was a statistically significant difference in carbon dioxide (P < 0.05), and the severity of postoperative atelectasis in the mechanical ventilation group was lower than that in the spontaneous breathing group (P < 0.05). In addition, there were no significant differences in the vital signs and baseline data of the patients (P > 0.05).

CONCLUSION

Laryngeal mask mechanical ventilation can reduce the incidence and severity of postoperative atelectasis in children undergoing day surgery, and we didn't encounter any complications such as reflux and aspiration in children during the perioperative period, so mechanical ventilation was recommended to be used for airway management.

TRIAL REGISTRATION

The clinical trial was registered retrospectively at the Chinese Clinical Trial Registry. ( https://www.chictr.org.cn . Registration number ChiCTR2300071396, Weiwei Cai, 15 May 2023).

Perioperative Pulmonary Atelectasis: Part I. Biology and Mechanisms

Pulmonary atelectasis is common in the perioperative period. Physiologically, it is produced when collapsing forces derived from positive pleural pressure and surface tension overcome expanding forces from alveolar pressure and parenchymal tethering. Atelectasis impairs blood oxygenation and reduces lung compliance. It is increasingly recognized that it can also induce local tissue biologic responses, such as inflammation, local immune dysfunction, and damage of the alveolar-capillary barrier, with potential loss of lung fluid clearance, increased lung protein permeability, and susceptibility to infection, factors that can initiate or exaggerate lung injury. Mechanical ventilation of a heterogeneously aerated lung (e.g., in the presence of atelectatic lung tissue) involves biomechanical processes that may precipitate further lung damage: concentration of mechanical forces, propagation of gas-liquid interfaces, and remote overdistension. Knowledge of such pathophysiologic mechanisms of atelectasis and their consequences in the healthy and diseased lung should guide optimal clinical management.

Acute Lobar Atelectasis

Lobar atelectasis (or collapse) is an exceedingly common, rather predictable, and potentially pathogenic companion to many forms of acute illness, postoperative care, and chronic debility. Readily diagnosed by using routine chest imaging and bedside ultrasound, the consequences from lobar collapse may be minor or serious, depending on extent, mechanism, patient vulnerability, abruptness of onset, effectiveness of hypoxic vasoconstriction, and compensatory reserves. Measures taken to reduce secretion burden, assure adequate secretion clearance, maintain upright positioning, reverse lung compression, and sustain lung expansion accord with a logical physiologic rationale. Both classification and logical approaches to prophylaxis and treatment of lobar atelectasis derive from a sound mechanistic knowledge of its causation.

Comparison between neck-first approach and thoracic approach during thoracoscopic esophagectomy

PURPOSE

This study aimed to compare the outcomes of the prior cervical and thoracic approaches of thoracoscopic esophagectomy in the prone position for esophageal cancer.

METHODS

We reviewed the records of 103 consecutive patients who underwent thoracoscopic esophagectomy in the prone position for esophageal cancer. Seventy-four patients underwent the prior cervical approach (Cervical group); the other 29 underwent the thoracic approach (Thoracic group). The perioperative outcomes of the two groups were compared.

RESULTS

Total operative time and volume of blood loss were not different between the two groups, but the median thoracoscopic time was significantly longer in the Thoracic group than in the Cervical group (296 vs. 210 min; P < 0.001). The incidence of recurrent nerve palsy was not different; however, the incidence of the postoperative pneumonia tended to be higher in the Thoracic group than in the Cervical group (20.7 vs. 10.8%; P = 0.188), and the duration of postoperative hospital stay was significantly longer in the Thoracic group than in the Cervical group (22 vs. 17 days; P = 0.032).

CONCLUSION

Patients who underwent thoracoscopic esophagectomy in the prone position via the prior cervical approach had better short-term outcomes than those who underwent the thoracic approach.

Oxygenation, inflammatory response and lung injury during one lung ventilation in rabbits using inspired oxygen fraction of 0.6 vs. 1.0

Maintaining adequate oxygenation during one-lung ventilation (OLV) requires high inspired oxygen fraction (FiO₂). However, high FiO₂ also causes inflammatory response and lung injury. Therefore, it remains a great interest to clinicians and scientists to optimize the care of patients undergoing OLV. The aim of this study was to determine and compare oxygenation, inflammatory response and lung injury during OLV in rabbits using FiO₂ of 0.6 vs. 1.0. After 30 minutes of two-lung ventilation (TLV) as baseline, 30 rabbits were randomly assigned to three groups receiving mechanical ventilation for 3 hours: the sham group, receiving TLV with 0.6 FiO₂; the 1.0 FiO₂ group, receiving OLV with 1.0 FiO₂; the 0.6 FiO₂ group, receiving OLV with 0.6 FiO₂. Pulse oximetry was continuously monitored and arterial blood gas analysis was intermittently conducted. Histopathologic study of lung tissues was performed and inflammatory cytokines and the mRNA and protein of nuclear factor kappa B (NF-κB) p65 were determined. Three of the 10 rabbits in the 0.6 FiO₂ group suffered hypoxemia, defined by pulse oximetric saturation (SpO₂) less than 90%. Partial pressure of oxygen (PaO₂), acute lung injury (ALI) score, myeloperoxidase (MPO), tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), mRNA and protein of NF-κB p65 were lower in the 0.6 FiO₂ group than in the 1.0 FiO₂ group. In conclusion, during OLV, if FiO₂ of 0.6 can be tolerated, lung injury associated with high FiO₂ can be minimized. Further study is needed to validate this finding in human subjects.

Low tidal volume ventilation with low PEEP during surgery may induce lung inflammation

Background

Compared to conventional tidal volume ventilation, low tidal-volume ventilation reduces mortality in cased of acute respiratory distress syndrome. The aim of the present study is to determine whether low tidal-volume ventilation reduces the production of inflammatory mediators in the lungs and improves physiological status during hepatic surgery.

Methods

We randomly assigned patients undergoing hepatectomy into 2 groups: conventional tidal-volume vs. low tidal-volume (12 vs. 6 mL•kg⁻¹ ideal body weight) ventilation with a positive end-expiratory pressure of 3 cm H₂O. Arterial blood and airway epithelial lining fluid were sampled immediately after intubation and every 3 h thereafter.

Results

Twenty-five patients were analyzed. No significant changes were found in hemodynamics or acid–base status during the study. Interleukin-8 was significantly elevated in epithelial lining fluid from the low tidal-volume group. Oxygenation evaluated immediately after admission to the post-surgical care unit was significantly worse in the low tidal-volume group.

Conclusions

Low tidal-volume ventilation with low positive end-expiratory pressure may lead to pulmonary inflammation during major surgery such as hepatectomy.

Trial registration

The effect of ventilatory tidal volume on lung injury during hepatectomy that requires transient liver blood flow interruption. UMIN000021371 (03/07/2016); retrospectively registered

Limb remote ischemic preconditioning attenuates lung injury after pulmonary resection under propofol-remifentanil anesthesia: a randomized controlled study

BACKGROUND

Remote ischemic preconditioning (RIPC) may confer the protection in critical organs. The authors hypothesized that limb RIPC would reduce lung injury in patients undergoing pulmonary resection.

METHODS

In a randomized, prospective, parallel, controlled trial, 216 patients undergoing elective thoracic pulmonary resection under one-lung ventilation with propofol-remifentanil anesthesia were randomized 1:1 to receive either limb RIPC or conventional lung resection (control). Three cycles of 5-min ischemia/5-min reperfusion induced by a blood pressure cuff served as RIPC stimulus. The primary outcome was PaO2/FIO2. Secondary outcomes included other pulmonary variables, the incidence of in-hospital complications, markers of oxidative stress, and inflammatory response.

RESULTS

Limb RIPC significantly increased PaO2/FIO2 compared with control at 30 and 60 min after one-lung ventilation, 30 min after re-expansion, and 6 h after operation (238 ± 52 vs. 192 ± 67, P = 0.03; 223 ± 66 vs. 184 ± 64, P = 0.01; 385 ± 61 vs. 320 ± 79, P = 0.003; 388 ± 52 vs. 317 ± 46, P = 0.001, respectively). In comparison with control, it also significantly reduced serum levels of interleukin-6 and tumor necrosis factor-α at 6, 12, 24, and 48 h after operation and malondialdehyde levels at 60 min after one-lung ventilation and 30 min after re-expansion (all P < 0.01). The incidence of acute lung injury and the length of postoperative hospital stay were markedly reduced by limb RIPC compared with control (all P < 0.05).

CONCLUSION

Limb RIPC attenuates acute lung injury via improving intraoperative pulmonary oxygenation in patients without severe pulmonary disease after lung resection under propofol-remifentanil anesthesia.

Sivelestat prevents cytoskeletal rearrangements in neutrophils resulting from lung re-expansion following one-lung ventilation during thoracic surgery

Patients undergoing lobectomy are at risk of developing acute lung injury resulting from one-lung ventilation (OLV) during surgery. We investigated the morphological and functional behavior of neutrophils in patients who underwent lobectomy and assessed the ability of sivelestat to inhibit neutrophil activity. This was a blinded randomized study. Sixteen patients who underwent lobectomy were given intravenous sivelestat (n = 8) or intravenous saline (n = 8). We studied the cytoskeletal rearrangements of circulating neutrophils by determining the localization of filamentous actin (F-actin). Pulmonary oxygenation was evaluated by measuring the partial pressure of arterial oxygen. We found that the number of circulating, F-actin-rimmed neutrophils increased during OLV and after lung re-expansion. Our results suggest that, in addition to the surgical procedure and OLV, re-expansion of the remaining lung after lobectomy increases the neutrophil activation levels. Furthermore, administration of sivelestat limited neutrophil activation and improved pulmonary oxygenation in our patients.