非侵入性呼吸肺功能檢查 - 以自然潮氣呼吸分析法於小動物臨床應用之研究 (家貓模式)

Abstract

呼吸/肺功能檢查是在臨床醫學中用以評估慢性氣道疾病、協助診斷、分級麻醉風險、瞭解病程變化與治療反應的客觀量化方法。在人類醫學中，呼吸/肺功能評估已是一項例行實施的臨床檢查；但小動物病患不可能如人類般可主動配合，因此無法使用在人類所實施之檢查方式，所以在獸醫目前仍缺乏呼吸/肺功能評估之廣泛應用。獸醫學上雖具有可直接測量肺順應性與氣道阻力之方法來獲取通氣機械性相關資料，然而這樣的測量方式需要全身麻醉與插管，對罹患呼吸系統疾病的小動物臨床病患而言具有風險，無法為多數伴侶動物飼主接受。因此，發展非侵入性的肺功能檢查方法是小動物呼吸臨床醫學的重要課題。 在過去二、三十年中，陸續有研究團隊評估不同的設備、技術是否有做為犬貓非侵入性呼吸肺功能檢查的潛力，這些嘗試包括了首先為嬰兒所設計發展的潮氣呼吸流速-容積環 (tidal breathing flow-volume loop, TBFVL)，以及在實驗鼠應用之氣壓式全體箱描述器 (barometric whole body plethysmography, BWBP)。然而這些方法均有其缺點，因此限制了在臨床犬貓病患廣泛應用以評估呼吸肺功能之可能性。此學位論文之目標即為研究分析自然潮氣呼吸訊號的其他方法，尋求一個可安全實施於小動物臨床病患、在臨床上適用、非侵入性的呼吸肺功能檢測方法。 研究成果呈現了一個以自然潮氣呼吸分析法為基礎，臨床上適用的非侵入性呼吸肺功能檢測方法。對呼吸訊號波形進行同步目視檢查可協助鑑定與去除干擾假波，並有助於記錄穩定的真實潮氣呼吸訊號。在整合之前不同設備、分析方法之優缺點後，自然潮氣呼吸可使用氣壓式全體箱描述器進行記錄，然後以不同於傳統氣壓式全體箱描述器分析方法、類似於傳統潮氣呼吸流速-容積環方法進行分析量化。在對呼吸訊號圖形的目視檢查下，經由偽氣流、偽容積的描繪，呼吸模式可以被定性化辨認；在正常與罹病動物間，自然潮氣呼吸模式有差異性存在。在特定疾病分類下，可尋找某些具有臨床意義的量化指標；以貓下呼吸道疾病為範例模式，某些特定參數可用以評估疾病嚴重度以及監測治療反應。藉由定性與定量自然潮氣呼吸訊號，可以評估呼吸系統/肺的機械性並用以作為一項非侵入性的呼吸肺功能檢測方法。

Respiratory or pulmonary function testing is an objective assessment for evaluating chronic airway diseases, for aiding diagnosis, for stratifying preoperative risk, and for assessing disease progression and therapeutic response in clinical medicine. Although respiratory/pulmonary function assessment is routinely performed in human medicine, it is not widely used in veterinary medicine because of the uncooperative nature of small animal patients. Direct measurement of lung compliance and resistance can be performed to provide information of ventilatory mechanics, nevertheless, the requirement for general anesthesia and intubation could increase risk for respiratory patients and is not acceptable for most of pet owners. As a result, the development of a non-invasive method for assessing pulmonary function is of great importance in small animal clinical medicine. In the past few decades, attempts utilizing different instruments and techniques have been made for potential non-invasive respiratory/pulmonary function testing in cats and dogs, such as tidal breathing flow-volume loop (TBFVL) method that first developed for use in human infants, or barometric whole body plethysmography (BWBP) system that initially used in laboratory rodents. The limits of either method prevent the extensive application of respiratory/pulmonary function assessment in clinical feline and canine patients. The aims of this dissertation were to find out an alternative methodology to analyze natural tidal breathing signals, and seek for a clinically applicable, non-invasive respiratory/pulmonary function testing procedure that can be safely applied on small animal clinical patients. The result of our study has demonstrated a clinically applicable, non-invasive respiratory/pulmonary function testing by natural tidal breathing analysis. Simultaneous visual inspection for breathing waveforms facilitated the identification of artefacts and allowed the recording of stable tidal breathing signals. With the combination of advantages of previously existed instruments and methods, natural tidal breathes can be recorded with the BWBP system and analyzed by a different way that similar to conventional TBFVL method. Breathing pattern recognition is possible under the depiction of pseudoflow and pseudovolume with visual inspection for graphic tracing. Natural tidal breathing patterns could differ between normal animals and diseased ones. In specific disease entity such as feline lower airway disease, selected indices could be useful in indicating disease severity and monitoring therapeutic response. By qualifying and quantifying natural tidal breathing signals, respiratory/pulmonary mechanics could be assessed accordingly and utilized as a non-invasive respiratory/pulmonary function testing.