Hyperoxia during one lung ventilation: Inflammatory and oxidative responses
ABSTRACT It is common practice during one lung ventilation (OLV) to use 100% oxygen, although this may cause hyperoxia- and oxidative stress-related lung injury. We hypothesized that lower oxygen (FiO(2) ) during OLV will result in less inflammatory and oxidative lung injury and improved lung function.
Twenty pigs (8.88 ± 0.84 kg; 38 ± 4.6 days) were assigned to either the hyperoxia group (n = 10; FiO(2) = 100%) or the normoxia group (n = 10; FiO(2) < 50%). Both groups were subjected to 3 hr of OLV. Blood samples were tested for pro-inflammatory cytokines and lung tissue was tested for these cytokines and oxidative biomarkers.
There were no differences between groups for partial pressure of CO(2) , tidal volume, end-tidal CO(2) , plasma cytokines, or respiratory compliance. Total respiratory resistance was greater in the hyperoxia group (P = 0.02). There were higher levels of TNF-α, IL-1β, and IL-6 in the lung homogenates of the hyperoxia group than in the normoxia group (P ≤ 0.01, 0.001, and 0.001, respectively). Myeloperoxidase and protein carbonyls (PC) were higher (P = 0.03 and P = 0.01, respectively) and superoxide dismutase (SOD) was lower in the lung homogenates of the hyperoxia group (P ≤ 0.001).
Higher myeloperoxidase, PC, and cytokine levels, and lower SOD availability indicate a greater degree of injury in the lungs of the hyperoxia animals, possibly from using 100% oxygen. In this translational study using a pig model, FiO(2) ≤ 50% during OLV reduced hyperoxic injury and improved function in the lungs. Pediatr Pulmonol. 2012. 47:979-986. © 2012 Wiley Periodicals, Inc.
- SourceAvailable from: Camila Ferreira Leite[Show abstract] [Hide abstract]
ABSTRACT: To investigate the anti-inflammatory effects of simvastatin in rats undergoing one-lung ventilation (OLV) followed by lung re-expansion. Male Wistar rats (n=30) were submitted to 1-h OLV followed by 1-h lung re-expansion. Treated group received simvastatin (40 mg/kg for 21 days) previous to OLV protocol. Control group received no treatment or surgical/ventilation interventions. Measurements of pulmonary myeloperoxidase (MPO) activity, pulmonary protein extravasation, and serum levels of cytokines and C-reactive protein (CRP) were performed. OLV significantly increased the MPO activity in the collapsed and continuously ventilated lungs (31% and 52% increase, respectively) compared with control (p<0.05). Treatment with simvastatin significantly reduced the MPO activity in the continuously ventilated lung but had no effect on lung edema after OLV. The serum IL-6 and CRP levels were markedly higher in OLV group, but simvastatin treatment failed to affect the production of these inflammatory markers. Serum levels of IL-1β, TNF-α and IL-10 remained below the detection limit in all groups. In an experimental one-lung ventilation model pre-operative treatment with simvastatin reduces remote neutrophil infiltration in the continuously ventilated lung. Our findings suggest that simvastatin may be of therapeutic value in OLV-induced pulmonary inflammation deserving clinical investigations.Acta cirurgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia 04/2013; 28(4):245-50. DOI:10.1590/S0102-86502013000400003 · 0.48 Impact Factor
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ABSTRACT: Despite general anesthesia still represents the standard to perform thoracic surgery, the interest toward alternative methods is increasing. These has evolved from the employ of just local or regional analgesia technique in completely alert patients (awake thoracic surgery), to more complex protocols entailing conscious sedation and spontaneous ventilation. The main rationale of these methods is to prevent serious complications related to general anesthesia and selective ventlation, such as tracheobronchial injury, acute lung injury, and cardiovascular events. Also, trends toward shorter hospitalization and reduced overall costs have been indicated in preliminary reports. Monitored anesthesia care thoracic surgery can be successfully employed to manage diverse oncologic conditions, such as malignant pleural effusion, peripheral lung nodules, and mediastinal tumors. Main non-oncologic indications include pneumothorax, emphysema, pleural infections, and interstitial lung disease. Furthermore, as the familiarity with this surgical practice has increased, major operations are now being performed this way. Despite the absence of randomized controlled trials, there is preliminary evidence that monitored anesthesia care protocols in thoracic surgery may be beneficial in high-risk patients, with non-inferior efficacy when compared to standard operations under general anesthesia. Monitored anesthesia care thoracic surgery should enter the armamentarium of modern thoracic surgeons, and adequate training should be scheduled in accredited residency programs.07/2013; 5(1). DOI:10.1111/1759-7714.12070
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ABSTRACT: We compared the effects of oleanolic acid (OA) versus dexamethasone on lung mechanics and histology, inflammation, and apoptosis in lung and distal organs in experimental sepsis. Seventy-eight BALB/c mice were randomly divided into two groups. Sepsis was induced by cecal ligation and puncture, while the control group underwent sham surgery. One hour after surgery, all animals were further randomized to receive saline (SAL), OA and dexamethasone (DEXA) intraperitoneally. Both OA and DEXA improved lung mechanics and histology, which were associated with fewer lung neutrophils and less cell apoptosis in lung, liver, and kidney than SAL. However, only animals in the DEXA group had lower levels of interleukin (IL)-6 and KC (murine analogue of IL-8) in bronchoalveolar lavage fluid than SAL animals. Conversely, OA was associated with lower inducible nitric oxide synthase expression and higher superoxide dismutase than DEXA. In the experimental sepsis model employed herein, OA and DEXA reduced lung damage and distal organ apoptosis through distinct anti-inflammatory mechanisms.Respiratory Physiology & Neurobiology 09/2013; 189(3). DOI:10.1016/j.resp.2013.08.019 · 1.97 Impact Factor