Perioperative management of patients with chronic obstructive lung disease : establishment of risk assessment for development of aspiration pneumonia after surgery

慢性阻塞性肺疾病(COPD)患者术后呼吸道并发症的发生率高于非COPD患者。我们假设COPD患者的呼吸道保护反射受损可能有助于肺吸入的发生。研究1：为了评估呼吸困难感觉和呼吸道保护反射之间的可能相互作用，我们评估了咳嗽反射的表现以及屏气中断后立即出现的呼吸困难感觉的类型和强度。我们发现1)呼吸困难感觉的存在不会损害自愿和柠檬酸诱导的咳嗽，2)空气饥饿感在反射性诱导咳嗽过程中增加和延长，3)在没有预先屏气的情况下，自愿或反射诱导咳嗽不会增加呼吸困难感觉。这些结果表明，呼吸困难感觉对慢性阻塞性肺疾病患者的呼吸道保护功能损害几乎没有贡献，更重要的是发生了…COPD患者呼吸困难的强度不能预测更多的肺吸入。研究2：为了评估COPD患者吞咽功能及其损害的机制，采用咽部持续注入蒸馏水的方法诱导吞咽。与健康受试者在阻力负荷时吞咽不同，注水导致的吞咽数量并没有异常减少。虽然在健康受试者中，吞咽主要是在呼气时诱导的，在吸气时很少诱导，但在COPD患者中经常观察到吸气或呼气末的吞咽。考虑到吸气或呼气末的不完全吞咽可以将咽部的物质吸入气管-支气管树，COPD患者的吞咽模式可能增加肺吸入性肺炎的风险。结论：COPD患者的吞咽模式应在术前通过咽部持续注入蒸馏水来评估，尽管呼吸困难的感觉很强烈。较少

Incidence of postoperative respiratory complication is higher in patients with chronic obstructive lung disease (COPD) than non COPD patients. We hypothesized that impairment of airway protective reflexes in COPD patients may contribute to development of pulmonary aspiration.Study 1 : In order to assess possible interaction between presence of dyspneic sensation and airway protective reflexes, we assessed performance of cough reflex and types and intensity of dyspneic sensation immediately after breakpoint of a breath-hold. We found 1) presence of dyspneic sensation did not impair voluntarily and citric acid-induced coughing, 2) air hunger sensation increased and prolonged during reflexically-induced coughing, 3) either voluntary or reflexically-induced coughing did not increase dyspneic sensation without preceding breath holding. These results suggest little contribution of dyspneic sensation to impairment of airway protective function in COPD patients, and more importantly occurrence … More of pulmonary aspiration is not predicted by intensity of dyspnea in COPD patients.Study 2 : In order to assess swallowing function and mechanisms of its impairment, swallowing was induced by continuous infusion of distilled water into the pharynx in COPD patients. Unlike swallowing during resistive load in healthy subjects, number of swallows induced by the water infusion was not abnormally reduced. While swallows were predominantly induced during expiration and rarely induced during inspiration in healthy subjects, inspiratory or end-expiratory swallows were frequently observed in COPD patients. Considering incomplete swallows during inspiration or end expiration could aspirate materials in the pharynx into the trachea-bronchial trees, the swallowing pattern of COPD patients may increase chance of pulmonary' aspiration pneumonia.In conclusion, swallowing patterns of COPD patients should be preoperatively assessed by continuous infusion of distilled water into the pharynx despite intensity of dyspneic sensation. Less