Airway management during left-sided gastrobronchial fistula repair after esophagectomy for esophageal carcinoma: A case report.

RATIONALE: Gastrobronchial fistula (GBF) is a rare but life-threatening complication of esophagectomy with gastric conduit reconstruction, and airway management during fistula repair is challenging. Here, we describe airway management in a patient undergoing left-sided GBF repair using video-assisted thoracoscopic surgery. PATIENT CONCERNS: A 63-year-old man diagnosed with esophageal carcinoma underwent esophagectomy with reconstruction by gastric pull-up and tabularization of the gastric conduit. Subsequently, about 8 weeks later, the patient presented with repeated pneumonia and a 1-week history of cough with significant sputum, dysphagia, and repeated fever. DIAGNOSIS: GBF, a rare postoperative complication, was located on the left main bronchus at 2 cm below the carina and was diagnosed based on findings from gastroscopy, flexible bronchoscopy, and thoracic computed tomography scan with contrast. INTERVENTIONS: We performed left-sided one-lung ventilation (OLV) under total intravenous anesthesia instead of inhalational anesthetics. The left-sided OLV, with positive end-expiratory pressure (PEEP) and nasogastric tube decompression, generated positive pressure across the fistula. It prevented backflow into the left main bronchus. Total intravenous anesthesia preserved hypoxic pulmonary vasoconstriction and prevented adverse effects associated with inhalational anesthetics. A right-sided, double-lumen endotracheal tube was inserted after anesthesia induction, and surgical repair was performed through a right-sided video-assisted thoracoscopic surgery. OUTCOMES: Intraoperative hemodynamics remained relatively stable, except for brief tachycardia at 113 beats/min. Arterial blood gas analysis revealed pH 7.17 and PaO2 89.1 mmHg upon 100% oxygenation, along with hypercapnia (PaCO2 77.1 mmHg), indicating respiratory acidosis. During OLV, pulse oximetry remained higher than 92%. The defect in the left main bronchus was successfully sutured after dissecting the fistula between the left main bronchus and the gastric conduit, and subsequently, OLV resulted in ideal ventilation. LESSONS: A left-sided GBF could lead to leakage from the OLV during surgery. Possible aspiration or alveolar hypoventilation due to this leakage is a major concern during airway management before surgical repair of the main bronchus.

Bioremediation of diesel and lubricant oil-contaminated soils using enhanced landfarming system.

Lubricant and diesel oil-polluted sites are difficult to remediate because they have less volatile and biodegradable characteristics. The goal of this research was to evaluate the potential of applying an enhanced landfarming to bioremediate soils polluted by lubricant and diesel. Microcosm study was performed to evaluate the optimal treatment conditions with the addition of different additives (nutrients, addition of activated sludge from oil-refining wastewater facility, compost, TPH-degrading bacteria, and fern chips) to enhance total petroleum hydrocarbon (TPH) removal. To simulate the aerobic landfarming biosystem, air in the microcosm headspace was replaced once a week. Results demonstrate that the additives of activated sludge and compost could result in the increase in soil microbial populations and raise TPH degradation efficiency (up to 83% of TPH removal with 175 days of incubation) with initial (TPH = 4100 mg/kg). The first-order TPH degradation rate reached 0.01 1/d in microcosms with additive of activated sludge (mass ratio of soil to inocula = 50:1). The soil microbial communities were determined by nucleotide sequence analyses and 16S rRNA-based denatured gradient gel electrophoresis. Thirty-four specific TPH-degrading bacteria were detected in microcosm soils. Chromatograph analyses demonstrate that resolved peaks were more biodegradable than unresolved complex mixture. Results indicate that more aggressive remedial measures are required to enhance the TPH biodegradation, which included the increase of (1) microbial population or TPH-degrading bacteria, (2) biodegradable carbon sources, (3) nutrient content, and (4) soil permeability.

Effects of soil organic matter and ageing on remediation of diesel-contaminated soil.

Bioremediation of diesel-contaminated soil was investigated for the effects of soil organic matter (SOM) and ageing time in two sets of experiments (Batch I and II, respectively). This study examined degradation efficiency in soil artificially contaminated with diesel oil (maximum total petroleum hydrocarbons (TPH) concentration of 9000 mg/kg soil). Batch I data showed that the values of the first-order degradation rate, k, were relatively high in the low-SOM soil batches. The quantity of SOM negatively correlated with the TPH degradation rates and with the total TPH degradation efficiency (%). Introduction of rhamnolipid to the soil proved to be a useful solution to resolve the problem of the residual TPH in the soil with high SOM. In Batch II, the k values decreased with the length of ageing time: 0.0245, 0.0128 and 0.0090 l/d in samples ST0 (freshly contaminated), ST38 (aged for 38 days) and ST101 (aged for 101 days), respectively. The TPH degradation efficiency (%) also decreased along with the ageing time. The research also applied molecular technology to analyse the bacterial community dynamics during the bioremediation course. Multivariate statistics based on terminal-restriction fragment length data indicated: 1) the soils with different SOM resulted in separate bacterial community structures, 2) ageing time created a variety of bacterial communities, 3) the bacterial community dynamics was associated with the hydrocarbon consumption. The SOM content in soils affected the TPH degradation rate and efficiency and the bacterial community structures. Aged soil is more difficult to remediate than freshly contaminated soil, and the resulting bacterial community was less dynamic and showed a lack of succession.