Pathophysiology of acute lung injury following esophagectomy

Abstract

KEY WORDS: acute lung injury, acute respiratory distress syndrome, esophagectomy, pathophysiology, postoperative complications.Esophagectomy is widely considered to be a high risk surgical approach. While improvements in surgical technique, perioperative monitoring, and postoperative care have led to a reduction in mortality following esophagectomy, early mortality remains between 5% and 10%. 1,2 Moreover, postoperative complications, involving predominantly the cardiorespiratory system, occur in up to 50% of patients. 3 Of the numerous respiratory complications that are associated with esophagectomy, acute lung injury (ALI) and its more severe form acute respiratory distress syndrome (ARDS) are of notable significance due to their prevalence and impact on early morbidity and mortality. 4 Reported rates of ALI and ARDS following esophagectomy are 23.8% and 14.5% respectively, the latter associated with 50% mortality. 4 While the existence of an accepted clinical definition for ALI/ARDS 5 has greatly contributed to the wider study of ALI/ARDS, continued variability in reporting practices has meant that the pathophysiology of this syndrome in the context of esophagectomy remains incompletely understood. Notwithstanding, patient-specific factors, the extent and nature of surgical trauma, and frequent requirement for periods of one-lung ventilation (OLV) are all anticipated to contribute to the development of ALI/ARDS following esophagectomy through their influence on systemic and local inflammatory responses. Consequently, the aim of this review is to define the pathophysiology of ALI/ARDS in the setting of esophagectomy and to explore potential strategies for prediction and prevention of this complication. PATHOPHYSIOLOGY OF ALI/ARDSAs first described by Ashbaugh et al. in 1967, ALI/ ARDS is recognized as a constellation of clinical, radiological, and physical abnormalities that collectively define an underlying picture of diffuse damage to the alveolar capillary unit and associated pulmonary gas exchange disturbance. 6 Central to this process is disruption of vascular endothelial and pulmonary epithelial linings and subsequent flooding of the alveolar and interstitial spaces with proteinaceous fluid, rich in inflammatory mediations and leukocytes. 7 Causes of ALI/ARDS can be broadly divided between those that result in either direct or indirect lung injury. Common sources of direct lung injury include: pneumonia, aspiration, trauma, reperfusion, and inhalation injury. Alternatively, sepsis, shock, polytrauma, and blood transfusion are common sources of indirect lung injury. 8 In patients undergoing esophagectomy precipitants of ALI/ARDS may reflect both local and systemic insults.

Rapid-onset acute respiratory distress syndrome after mastectomy in a breast cancer patient

“…[ 6 ] The complement effect results in accumulation of activated neutrophils in the pulmonary tissue after cardiopulmonary bypass. [ 5 , 6 ] In our case, there were various risk factors for the development of postoperative ARDS.…”

“…Boshier et al reviewed the pathophysiology of post-esophagectomy ARDS. [ 5 ] The levels of pro-inflammatory cytokines, such as IL-6 and IL-8 were found to be markedly elevated in the lung tissue and pleural fluid. In the lavage, the post-esophagectomy levels of neutrophil elastase, granulocyte-colony stimulating factor, secretory leukocyte protease inhibitor, and nitrogen-free radicals were found to be elevated.…”

“…The perioperative events such as large intraoperative crystalloid fluid infusions, massive transfusion, hypertension, hypotension, high levels of oxygen supplementation, and cardiac ischemia. [ 5 – 7 ]…”

Administration of Corticosteroids, Ascorbic Acid, and Thiamine Improves Oxygenation after Thoracoscopic Esophagectomy

“…Impaired oxygenation after esophagectomy may be related to the systemic inflammatory response syndrome, which is invoked by tissue injury associated with surgery and one lung ventilation via inflammatory responses and oxidative stress. 4) This impairment is believed to begin intraoperatively and continue for several days. 24) Even after minimally invasive esophagectomy, which is less invasive than open esophagectomy, impaired oxygenation occurs and necessitates supportive care.…”

Pathophysiological Approaches of Acute Respiratory Distress syndrome: Novel Bases for Study of Lung Injury

“…Indeed, IR damage is combined with severe inflammatory response, including neutrophils infiltration in the lung tissue as well as microvascular injuries and edema. These injury pathways resulted in ARDS after some quirurgic maunevers in esophagectomy and in the others similar techniques [ 74 ].…”