以Sensor medic 3100A高頻呼吸器探討在體外肺氣漏模型中之肺氣漏狀況

Determinants of Airleak Flow during SensorMedics 3100A High-frequency Oscillatory Ventilation in an Isolated Airleak Lung Model

劉道遠(Tao-Yuan Liu)

指導教授 ： 陳宏一

長榮大學/健康科學學院/醫學研究所/碩士(2013年)

https://doi.org/10.6833/CJCU.2013.00036

摘要

在使用高頻振盪呼吸器治療新生兒的肺部疾病時，在呼吸器設定逐漸調高的時候，很容易造成肺氣漏的現象。高頻振盪呼吸器常被運用於肺氣漏狀況的治療。我們必須先了解影響肺氣漏的基本機轉，才能以溫和有效的設定加以運用。但是怎樣的設定最理想，既可以順利的讓肺泡打開，但是又不致於加重肺氣漏的情形，各方一直有些不同的見解。本研究乃利用10隻紐西蘭大白兔的肺臟來模擬新生兒的肺臟，在取出體外後以一般呼吸器來維持其換氣，藉由較高的進氣壓力設定來製造肺氣漏的模型，再使用SensorMedics 3100A高頻振盪呼吸器加以治療，藉由調整不同的平均氣道壓力(mean airway pressure)、頻率(frequency)、振幅(amplitude pressure，ΔP)及進氣時間百分比(percentage of inspiratory time，Ti)等呼吸器設定，來測定氣漏的情形，以期能找出最理想的呼吸器設定。所得的實驗數據以廣義估計方程式（generalized estimating equation，GEE）加以分析。實驗結果顯示，當平均氣道壓力(MAP)由5 cm H2O逐步調高到35 cm H2O時，肺氣漏流量呈現顯著的上升（p < 0.001, coefficients ± SE = 51.4 ± 4.6 mL/min/cm H2O）。當頻率(frequency)由5 Hz逐步調高到15 Hz時，肺氣漏流量並無顯著的改變 (p = 0.111)。肺氣漏流量隨著振幅(ΔP)的改變呈現正相關（p < 0.001, coefficients ± SE = 5.1 ± 0.8 mL/min/cm H2O）。當平均氣道壓力(MAP)維持在10 cm H2O 時，進氣時間百分比（Ti）和肺氣漏流量只呈現些微相關性(p = 0.058)。當平均氣道壓力(MAP)維持在20 cm H2O 時，肺氣漏流量和進氣時間百分比（Ti）呈現顯著相關性（p <0.05, coefficients ± SE = 4.0 ± 0.4 mL/min/%）。
本實驗獲得的結論為：平均氣道壓力(MAP)是影響肺氣漏流量的主要獨立因素，然而振幅(ΔP) 和進氣時間百分比（Ti）則影響較小。
在SensorMedics 3100A高頻振盪呼吸器的合理設定範圍內，頻率(frequency)設定改變並不會影響肺氣漏流量。

關鍵字

高頻振盪呼吸器 ； 肺氣漏 ； 平均氣道壓力 ； 紐西蘭大白兔

並列摘要

Airleaks often occur when an aggressive recruitment maneuver is applied during high frequency oscillatory ventilation (HFOV). Optimal application of HFOV using a gentler and effective protocol requires an understanding of the basic mechanism affecting airleak. The purpose of our experiment was to determine the effect of mean airway pressure (MAP), frequency, amplitude pressure (ΔP) and percentage of inspiratory time (Ti) on airleak flow using an isolated lung model ventilated with a SensorMedics 3100A HFOV. We performed a crossover non randomized experiment using the repeated measurement method to test the hypothesis that MAP is the major determinant for airleak. The lungs of 10 healthy juvenile New Zealand white rabbits were isolated and ventilated with high peak pressure to create airleak. The dataset obtained was analyzed by generalized estimating equation (GEE) method. Airleak was significantly increased as MAP was raised from 5 cm H2O to 35 cm H2O (p < 0.001, coefficients ± SE = 51.4 ± 4.6 mL/min/cm H2O). Leakage flow was not altered as frequency was raised from 5 Hz to 15 Hz (p = 0.111). Leakage flow was positively correlated with changes in ΔP (p < 0.001, coefficients ± SE = 5.1 ± 0.8 mL/min/cm H2O). The relationship of Ti and leakage flow only reached a borderline significance when MAP was kept at 10 cm H2O (p = 0.058). Leakage flow increased significantly as Ti increased when MAP was kept at 20 cm H2O (p <0.05, coefficients ± SE = 4.0 ± 0.4 mL/min/%). We conclude that MAP is the main independent factor affecting airleak whilst ΔP and Ti exerted lesser effect. Within the operational range of SensorMedics 3100A, frequency did not affect airleak.

並列關鍵字

Airleak ； high frequency oscillatory ventilation ； SensorMedics 3100A

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