臂叢阻滯麻醉可以阻斷同側正中神經，尺神經，橈神經和肌皮神經，故其經常被用於上肢手術中麻醉和/或鎮痛。臂叢阻滯麻醉也可以阻滯同側交感神經，導致同側上肢血管擴張（動脈和靜脈）和血流增加。脈沖多普勒超聲技術可以檢測到這些局部的血流動力學變化。文獻回顧表明迄今為止發表的大部分報道片面地評估了臂叢阻滯麻醉後上肢的局部血流動力學變化缺乏全面而系統的研究，並且報道中關於脈沖多普勒超聲技術用於上肢局部血流動力學測量的可靠性和可重復性的數據也很有限。此外，上肢的局部血流動力學變化是否與測量的位置或者使用的臂叢阻滯麻醉技術有關尚且未知。 / 我假設脈沖多普勒超聲是壹種可靠的測量上肢血流動力學變化的方法，它可以系統地定量測定臂叢阻滯麻醉後上肢的局部血流動力學變化，確定這些變化在上肢不同部位的差異，以及確定不同臂叢阻滯麻醉技術後局部血流動力學變化的差異。以下的部分列舉了本博士課題中開展的壹系列研究來證實我的假設。 / 第壹，我們在12個健康年輕誌願者中（年齡21-34歲）用脈沖多普勒超聲在上肢肱動脈和指掌側總動脈進行血流動力學測量，評估其在觀察者內和觀察者間的差異性。兩個觀察者獨立進行了測量。測量的指標包括收縮期峰值血流速度（厘米/秒），舒張末期血流速度（厘米/秒），收縮期峰值血流速度和舒張末期血流速度比值，平均速度（厘米/秒），時均速度（厘米/秒），阻力指數，搏動指數，動脈直徑（厘米），和血流量（毫升/分鐘）。結果顯示脈沖多普勒超聲是壹種可靠的方法，可用來重復測量上肢的局部血流動力學參數（組內相關系數>0.9）. / 第二，我們在8個病人中（年齡24-70歲）系統地評估了超聲波引導下的腋路臂叢神經阻滯後同側肱動脈的局部血流動力學變化。結果表明臂叢神經阻滯後最早的變化是脈沖多普勒頻譜波形的變化，其波形由三相變為單相，舒張期血流曲線擡升。隨著時間推移，收縮期峰值血流速度，舒張末期血流速度，平均速度，時均速度，動脈直徑，和血流量均顯著增加，收縮期峰值血流速度和舒張末期血流速度比值，阻力指數，搏動指數顯著降低。大部分變化發生在神經阻滯後5分鐘。在所有的局部血流動力學指標中，舒張末期血流速度表現出最顯著的變化（3.7倍），其增加超過收縮期峰值血流速度（1.5倍）和平均速度（2.8倍）。 / 第三，利用15個病人（年齡23-70歲），我們評估了超聲波引導下的鎖骨上臂叢神經阻滯後上肢近端動脈（肱動脈）和遠端動脈（指掌側總動脈）血流動力學變化的差異。臂叢神經阻滯之後，在能量多普勒圖像上，指掌側總動脈表現出更明顯的血管擴張。在脈沖多普勒頻譜波形中，兩個動脈均出現舒張早期的反流消失以及舒張期曲線擡升。另外，收縮期峰值血流速度，舒張末期血流速度，平均速度，時均速度，動脈直徑，和血流量增加，收縮期峰值血流速度和舒張末期血流速度比值，阻力指數，搏動指數顯著降低。這些指標的相對變化在指掌側總動脈比肱動脈更顯著。此研究中，4個病人出現對側手部溫度的增加，以此推測局部麻醉藥的雙側擴散。 / 第四，我們開展了壹項前瞻性隨機對照研究來比較腋路和鎖骨上臂叢神經阻滯引起的局部血流動力學變化的不同。兩組病人人口統計學資料類似。兩種臂叢神經阻滯技術均引起肱動脈和指掌側總動脈收縮期峰值血流速度，舒張末期血流速度，平均速度，時均速度，動脈直徑，和血流量的顯著增加，收縮期峰值血流速度和舒張末期血流速度比值，阻力指數，搏動指數顯著降低。跟腋窩方法相比，鎖骨上技術能夠引起肱動脈時均速度和血流量更顯著的增加。然而，在感覺神經阻滯起效方面，腋窩方法比鎖骨上方法更快。 / 總之，脈沖多普勒超聲可重復地測量肱動脈和指掌側總動脈的血流動力學參數及其變化。臂叢阻滯麻醉引起肱動脈和指掌側總動脈脈沖多普勒頻譜形態的變化，血流速度的增加和血流量的增加。這些局部血流動力學變化在指掌側總動脈中比肱動脈更顯著。鎖骨上臂叢神經阻滯比腋窩方法引起更顯著的局部血流動力學變化。臨床醫生可以利用上肢遠端動脈的局部血流動力學變化來評價臂叢阻滯麻醉的交感神經阻滯效應。麻醉醫師還可以根據這些發現為術後需要較好血流灌註的上肢血管手術選取臂叢神經阻滯方法。 / Brachial plexus block (BPB), which produces sensory and motor blockade of the ipsilateral median, ulnar, radial and musculocutaneous nerves, is frequently used for anesthesia and/or analgesia during surgical procedures of the upper extremity. BPB also produces ipsilateral sympathetic nerve blockade that is characterized by vasodilatation (venous and arterial), and an increase in blood flow to the ipsilateral upper extremity. Pulsed wave Doppler (PWD) ultrasound (US) has been used to evaluate these regional hemodynamic changes. A review of the literature shows that most published reports to date have only partially evaluated the regional hemodynamic changes in the upper extremity after a BPB. There are also limited data demonstrating that PWD US is a reliable or reproducible method of quantifying the regional hemodynamic changes in the upper extremity. Moreover, it is also not known whether the regional hemodynamic changes vary with the site of measurement or the technique of BPB used. / I hypothesized that PWD US is a reliable method for measuring regional hemodynamic parameters in the upper extremity. It can be used to comprehensively quantify the regional hemodynamic changes after a BPB and to determine the extent of these changes at different sites in the upper extremity and after different techniques for BPB. The following section outlines a series of studies that I undertook during this PhD project to corroborate my hypothesis. / Firstly, we sought to assess the intra-observer and inter-observer variability of measuring regional hemodynamic parameters, in the brachial and common palmar digital arteries of the upper extremity, using PWD US in 12 healthy young volunteers aged 21-34 yrs. The measurements were performed independently by two observers. Measured hemodynamic parameters included peak systolic velocity (PSV, cm/s), end diastolic velocity (EDV, cm/s), ratio of PSV and EDV (S/D), mean velocity (Vmean, cm/s), time-averaged mean velocity (TAVM, cm/s), resistance index (RI), pulsatility index (PI), the arterial diameter (d, cm), and blood flow (mL/min). The results showed that PWD US is a reliable and reproducible method of measuring regional hemodynamic parameters in the upper extremity (ICC>0.9). / Secondly, we comprehensively evaluated the regional hemodynamic changes in the ipsilateral brachial artery after an ultrasound guided (USG) axillary BPB in eight adult patients aged 24-70 yrs. Our results suggested that the earliest change after the BPB was a change in the morphology of the PWD spectral waveform from a triphasic to a monophasic waveform and an elevation in the diastolic blood flow velocity. Over time, there was also a significant increase in PSV, EDV, Vmean, TAVM, d, and blood flow, and a decrease in S/D ratio, RI, and PI. Most of these changes were seen as early as 5 minutes after the block. The increase in EDV (3.7-fold) was the most notable change, and it was significantly greater than the increase in PSV (1.5-fold) and Vmean (2.8-fold). / Thirdly, the regional hemodynamic changes in the proximal (brachial artery) and distal (common palmar digital artery) artery of the upper extremity after an USG supraclavicular BPB was investigated in 15 adult patients aged 23-70 yrs. After the block, the common palmar digital artery showed more obvious vasodilatation on the power Doppler US scan. In the PWD spectral waveform, and in both arteries studied, the protodiastolic blood flow disappeared and there was an elevation of the diastolic curve. Also there was a significant increase in PSV, EDV, Vmean, TAVM, d, and blood flow, and a significant reduction in S/D ratio, PI and RI in both arteries. Relative changes of these parameters were greater in the common palmar digital artery than in the brachial artery. In this study, bilateral spread of local anesthetic was observed in 4 patients, as evidenced by an increase of skin temperature on the contralateral hand. / Fourthly, a prospective and randomized study was conducted to compare the regional hemodynamic changes in the upper extremity after an axillary and supraclavicular BPB. The two study groups were similar with respect to demographic data. Both axillary and supraclavicular BPB caused a significant increase in PSV, EDV, Vmean, TAVM, d, and blood flow, and a significant reduction in S/D ratio, PI and RI in both the brachial and common palmar digital arteries. Compared with the axillary approach, the supraclavicular approach produced significantly greater increases in TAVM and blood flow in the brachial artery. However, the onset of sensory blockade was faster after the axillary BPB than with the supraclavicular BPB. / In conclusion, PWD US is a reliable and reproducible method for quantifying the regional hemodynamic parameters in both the brachial and common palmar digital arteries. BPB produces a change in the morphology of the PWD spectral waveform, arterial vasodilatation, an increase in blood flow velocity, and an increase in blood flow in both the ipsilateral brachial and common palmar digital arteries. These changes in regional hemodynamic parameters were more profound in the common palmar digital artery than in the brachial artery. Also these changes were more significant after a supraclavicular BPB than after an axillary BPB. These findings will allow clinicians to evaluate the sympathetic effect of a BPB using regional hemodynamic changes in the distal arteries of the upper extremity. These findings will also allow anesthesiologists to make an evidence-based choice on the techniques of BPB for vascular surgery of the upper extremity when good tissue perfusion is desirable postoperatively. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Jiawei. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 182-192). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / TABLE OF CONTENTS / ABSTRACT / 中文摘要 / STATEMENT OF WORK / ACKNOWLEDGMENTS / PUBLICATIONS AND PRESENTATIONS / LIST OF ABBREVIATIONS / LIST OF TABLES / LIST OF FIGURES / Chapter CHAPTER 1 --- Introduction / Chapter 1.1 --- Introduction / Chapter 1.2 --- Aims of the project / Chapter 1.3 --- Outline of the thesis / Chapter CHAPTER 2 --- Literature Review / Chapter 2.1 --- Introduction / Chapter 2.2 --- Why regional hemodynamic changes occur after a BPB / Chapter 2.2.1 --- Anatomy of the sympathetic nervous system in the upper extremity / Chapter 2.2.2 --- The anatomic relationship between the sympathetic nerves and the brachial plexus / Chapter 2.2.3 --- Sympathetic efferents to blood vessels in the upper extremity / Chapter 2.3 --- Methods used to measure regional hemodynamic changes / Chapter 2.3.1 --- Skin and muscle blood flow / Chapter 2.3.2 --- Regional hemodynamic measurements using PWD US / Chapter 2.3.2.1 --- Basics of Doppler ultrasound / Chapter 2.3.2.2 --- Principles of blood flow / Chapter 2.3.2.3 --- Spectral analysis of blood flow using PWD US / Chapter 2.4 --- Published data on regional hemodynamic changes after BPB / Chapter 2.4.1 --- Skin temperature / Chapter 2.4.2 --- Cutaneous and muscular blood flow / Chapter 2.4.3 --- Regional hemodynamic measurements on major arterial branches of the upper extremity / Chapter 2.5 --- Introduction of BPB / Chapter 2.5.1 --- Anatomy of the brachial plexus / Chapter 2.5.2 --- Techniques for performing BPB / Chapter 2.5.3 --- USG BPB / Chapter 2.5.3.1 --- History / Chapter 2.5.3.2 --- Advantages of ultrasound guidance for peripheral nerve blockade / Chapter CHAPTER 3 --- Methodology / Chapter 3.1 --- Introduction / Chapter 3.2 --- Patient preparations / Chapter 3.3 --- Regional hemodynamic measurement / Chapter 3.3.1 --- Ultrasound equipment / Chapter 3.3.2 --- Patient position / Chapter 3.3.3 --- Regional hemodynamic measurements using PWD US / Chapter 3.3.3.1 --- Optimizing settings for B-Mode US / Chapter 3.3.3.2 --- Optimizing settings for PWD US / Chapter 3.3.3.3 --- Measurement of regional hemodynamic parameters / Chapter 3.3.4 --- Measurement of diameter (d) and blood flow (Q) / Chapter 3.4 --- USG BPB / Chapter 3.4.1 --- USG axillary BPB / Chapter 3.4.1.1 --- Scout scan / Chapter 3.4.1.2 --- Aseptic precautions / Chapter 3.4.1.3 --- USG axillary BPB / Chapter 3.4.2 --- USG supraclavicular BPB / Chapter 3.4.2.1 --- Scout scan / Chapter 3.4.2.2 --- Aseptic precautions / Chapter 3.4.2.3 --- USG supraclavicular BPB / Chapter 3.5 --- Outcome data after the BPB / Chapter CHAPTER 4 --- Measurement of Regional Hemodynamic Parameters in the Upper Extremity Using Pulsed Wave Doppler Ultrasound: A Reliability Study / Chapter 4.1 --- Introduction / Chapter 4.2 --- Methods / Chapter 4.2.1 --- Subjects / Chapter 4.2.2 --- Study design / Chapter 4.2.3 --- Data acquisition / Chapter 4.2.4 --- Statistical analysis / Chapter 4.3 --- Results / Chapter 4.4 --- Discussion / Chapter 4.4.1 --- Summary of main findings / Chapter 4.4.2 --- Compared with previous studies / Chapter 4.4.3 --- Sources of measurement variability / Chapter 4.4.4 --- Explanation for the variation in the changes in various regional hemodynamic parameters / Chapter 4.5 --- Conclusion / Chapter CHAPTER 5 --- Regional Hemodynamic Changes after an Axillary BPB: A Pulsed Wave Doppler Ultrasound Study / Chapter 5.1 --- Introduction / Chapter 5.2 --- Methods / Chapter 5.2.1 --- Patient enrollment / Chapter 5.2.2 --- Patient preparation / Chapter 5.2.3 --- Measurement of baseline regional hemodynamic parameters / Chapter 5.2.4 --- USG axillary BPB / Chapter 5.2.5 --- Outcome data after the BPB / Chapter 5.2.6 --- Sensory and motor assessments after the BPB / Chapter 5.2.7 --- Statistical Analysis / Chapter 5.3 --- Results / Chapter 5.4 --- Discussion / Chapter 5.4.1 --- Summary of main findings / Chapter 5.4.2 --- Limitations / Chapter 5.4.3 --- Changes in PWD spectral waveform / Chapter 5.4.4 --- Changes in regional hemodynamic parameters / Chapter 5.4.5 --- Increase in skin temperature / Chapter 5.4.6 --- Effects of local anesthetic / Chapter 5.5 --- Conclusion / Chapter CHAPTER 6 --- Does a Supraclavicular Brachial Plexus Block Induce Comparable Hemodynamic Changes in the Proximal and Distal Arteries of the Upper Extremity? / Chapter 6.1 --- Introduction / Chapter 6.2 --- Methods / Chapter 6.2.1 --- Patient recruitment / Chapter 6.2.2 --- Patient preparation / Chapter 6.2.3 --- Measurement of baseline regional hemodynamic parameters, arterial diameter and blood flow / Chapter 6.2.4 --- USG supraclavicular BPB / Chapter 6.2.5 --- Outcome measurements after the BPB / Chapter 6.2.6 --- Statistical analysis / Chapter 6.3 --- Results / Chapter 6.4 --- Discussion / Chapter 6.4.1 --- Summary of the main findings / Chapter 6.4.2 --- Limitations / Chapter 6.4.3 --- Changes in the PWD spectral waveform / Chapter 6.4.4 --- Explanation of the differences in regional hemodynamic changes in the distal and proximal arteries after BPB / Chapter 6.4.5 --- Increase in skin temperature and its relation to blood flow / Chapter 6.4.6 --- Bilateral sympathetic effect after supraclavicular BPB / Chapter 6.4.7 --- Other findings of this study / Chapter 6.5 --- Conclusion / Chapter CHAPTER 7 --- Does a Supraclavicular Brachial Plexus Block Induce Greater Changes in Regional Hemodynamics than an Axillary Brachial Plexus Block? / Chapter 7.1 --- Introduction / Chapter 7.2 --- Methods / Chapter 7.2.1 --- Sample size estimation / Chapter 7.2.2 --- Exclusion criteria / Chapter 7.2.3 --- Randomized allocation / Chapter 7.2.4 --- Preparations before the ultrasound scan / Chapter 7.2.5 --- Measurement of baseline regional hemodynamic parameters, diameter and blood / Chapter 7.2.6 --- USG axillary and supraclavicular BPB / Chapter 7.2.7 --- Outcome measurements after the BPB / Chapter 7.2.8 --- Statistical analysis / Chapter 7.3 --- Results / Chapter 7.4 --- Discussion / Chapter 7.4.1 --- Summary of the main findings / Chapter 7.4.2 --- Limitations / Chapter 7.4.3 --- Change in the PWD spectral waveform / Chapter 7.4.4 --- Differences in regional hemodynamic changes between the 2 study groups / Chapter 7.4.5 --- Differences in sensory and motor blockade between the 2 study groups / Chapter 7.4.6 --- Changes in skin temperature / Chapter 7.5 --- Conclusion / Chapter CHAPTER 8 --- Summary and Conclusions / APPENDIX / REFERENCES