理解臨床血流動力學培訓課件

1、理解臨床血流動力學理解臨床血流動力學The physiologic paradigm that clinicians reference in their attempts to explain and understand the biology of both healthy and critically ill patients has been in evolution for more than 100 years.（臨床醫(yī)師嘗試著闡述和了解健康和危重癥患者而借助的生理學范式已經(jīng)發(fā)展100多年了。）Interestingly, our understanding of the cli

2、nical circulation has always been thought of as complete, （有趣的是，人們對臨床循環(huán)的理解一直被視為“很完整”，）with creative clinicians invoking a variety of reasons to explain away apparent discrepancies between commonly used mental models and the realities of clinical medicine.（而富有創(chuàng)新性的臨床醫(yī)師則希望通過種種解釋消除常用思維模式和臨床醫(yī)學現(xiàn)實之間顯著的差異。）

3、2理解臨床血流動力學The physiologic paradigm that The most primitive formulation of the circulation entails simple conservation of matter:（最原始的循環(huán)公式蘊含著簡單的物質守恒：） Cardiac Output = Stroke Volume x Heart Rate = Qt = SV x HR （心輸出量（CO）=每博量心率=Qt = SVHR） This statement, while obviously always true, offers sapient prac

4、titioners little insight into why the circulation in a articular patient might be unacceptable, and how they might rationally intervene. （很顯然，該表述很正確，卻幾乎沒有為智慧的工作者深入了解為何個別患者的循環(huán)可能不穩(wěn)定以及如何進行合理的干預提供幫助。）3理解臨床血流動力學The most primitive formulationDuring the mid-20th century, a relatively complete paradigm for

5、understanding the role of the enous return in controlling the cardiac output was refined by Guyton and his co-workers, and has been repetitively validated since it was first described (refs Jacobsohn, Magder, Guyton, Sylvester).在20世紀中葉，Guyton及其同事修訂了一個相對完善、關于了解靜脈回心血量在控制心輸出量中的作用的范式，該范式從首次被描述就進行了反復驗證。A

6、lthough not complete, this theory was powerful in thehands of those who understood it.盡管該理論還不完善，卻對已理解該理論的人群產(chǎn)生了很大的作用。4理解臨床血流動力學During the mid-20th century, aThe balloon-tipped, flow directed, thermistor equipped pulmonary artery catheter heralded the subsequent era of the understanding of the clinica

7、l circulation.裝備有末端套囊、血流導向以及熱敏電阻的肺動脈導管，預示著理解臨床循環(huán)時代的到來。This device, coupled with a deep understanding of themechanics of left ventricular function heralded the era in which the circulation and all of its pathology wereunderstood from the perspective of the left-ventricle which some now refer to as th

8、e LV centered view of thecirculation (Sagawa).對肺動脈導管及左心室力學功能的深入了解預示著從左心室的視角來理解循環(huán)以及循環(huán)病理學時代的來臨。5理解臨床血流動力學The balloon-tipped, flow direcFor those who trained in that paradigm, preload, afterload, and contractility were the determinants of cardiac output:接受該范式培訓的人群應該了解，前負荷、后負荷以及收縮力都是心輸出量的決定因素： Cardiac O

9、utput = CO = MAP-RAP SVR(Where MAP = Mean Arterial Pressure, RAP = Right Atrial Pressure and SVR = Systemic Vascular Resistance)（MAP=平均動脈壓，RAP=右心房壓，SVR=體循環(huán)阻力）Some patients have a right heart limited circulation, which can be formulated using a very similar equation: 有些患者存在右心循環(huán)受限，可以用一相似的方程式計算心輸出量： _

10、CO = PA - LAP _ PVR(Where PA = Mean Pulmonary Artery Pressure, LAP = Left Atrial Pressure, and PVR = Pulmonary Vascular Resistance).（PA=平均肺動脈壓，LAP=左心房壓，PVR=肺血管阻力）。6理解臨床血流動力學For those who trained in that Nevertheless, the LV centered view of the circulation focused on preload, afterload, and contract

11、ility, and was frustrated by a variety of obstacles.然而，以左室為中心觀察循環(huán)主要以前負荷、后負荷和收縮力為主要研究對象，但若遇到一些障礙，則結果就相形見絀了。 The most important was the poor correlation between measured filling pressures and left ventricular end-diastolic volumes as assessed by echocardiography (refs Kumar,Hofer, Kramer).最重要的是，通過超聲心動

12、圖進行評估發(fā)現(xiàn)，充盈壓和左心室舒張末容積之間的相關性較差。Echocardiography has documented that LV compliance is far more dynamic than anyone believed prior to itswidespread clinical use (Coriat).通過超聲心動圖證實，左心室順應性比之前認為已廣泛應用于臨床的任一參數(shù)更優(yōu)越。7理解臨床血流動力學Nevertheless, the LV centered The other, more insidious problem with the LV centered w

13、orld-view is that adherents tend to regard RAP almost exclusively as an index of circulatory volume, forgetting that it is the downstream hydrostatic resistance to venous return in the model of Guyton:另一方面，以左心室為中心觀察循環(huán)存在的潛在問題為，支持者更趨向于認為，RAP幾乎為循環(huán)容量唯一的指標，而遺忘了在Guyton模型中，RAP為下游流體靜力學阻力： VR = CO = Pms RAP

14、RVR(Where VR = Venous Return, RAP = Right Atrial Pressure, and RVR = Resistance to Venous Return)（VR=靜脈回心血量，RAP=右心房壓，RVR=靜脈回心阻力）The circulation in any patient at any moment in time is the product of the interaction of the venous circuit with the heart (the pump). The RAP is a product of that interac

15、tion.對于任一患者的任一時刻，循環(huán)都是心臟（泵）和靜脈回路相互作用的產(chǎn)物。RAP即為該相互作用的產(chǎn)物。8理解臨床血流動力學The other, more insidious probAll of this has produced the present understanding of clinical hemodynamics, which is predicated on a synthesis of venous return and cardiac physiology (Sylvester, Jacobsohn).當前對臨床血流動力學的理解綜合了靜脈回心量和心臟生理學。This

16、 model can be used to generate a series of questions that can guide the assessment of a patient in shock.該模型可以解釋一系列問題以指導休克患者的評估。What is Shock？Shock is globally inadequate perfusion of tissues sufficient to produce both tissue hypoxia and organ dysfunction. 休克為全身組織灌注不足導致組織缺氧和器官功能失調。9理解臨床血流動力學All of t

17、his has produced the pWhile shock is classically associated with hypotension, there is increasing acceptance of the contention that hypotension is a relatively late indicator of shock, and that clinicians should be more attuned to organ system dysfunction as evidence of shock.雖然休克通常與低血壓有關，然而有越來越多的觀點

18、認為，低血壓已是休克相對“晚期”的指標，臨床醫(yī)師更應習慣于以器官系統(tǒng)功能失調作為休克的證據(jù)（表1）。Signs of Shock: - altered mentation- oliguria- decreased mixed venous or central venous saturation- hypotension, abnormal heart rate- lactic acidosis- peripheral cyanosis (variable)10理解臨床血流動力學While shock is classically assIn both the critical care an

19、d trauma literature, the endpoints for resuscitation have also evolved.Whiletraditional endpoints such as mean arterial pressure and central venous pressure are still regarded as important,increasing emphasis is being placed on the mixed/central venous oxygen saturation (Ladakis) and lactate levels

20、in the blood.在重癥監(jiān)護和創(chuàng)傷醫(yī)學文獻中，復蘇終點也已不斷演變。雖然傳統(tǒng)的復蘇終點（如，平均動脈壓和中心靜脈壓）仍然很重要，但越來越強調混合/中心靜脈氧飽和度和血乳酸水平。11理解臨床血流動力學In both the critical care and The combination of inexpensive and readily available serum lactates and increasing appreciation of theprevalence of hyperchloremic acidosis in the setting of large vol

21、ume resuscitation has led to the near abandonment of the base excess/deficit as a guide to the adequacy of resuscitation.在大容量復蘇的過程中，作為復蘇適度的風向標，方便快捷的血清乳酸測定結合日益受寵的高氯血癥酸中毒已經(jīng)逐漸取代堿過量/缺失。Several publications over the past several years have dampened enthusiasm for the use of central venous oxygenation (Ch

22、awla, Sander, Varpula), but it nevertheless remains a very useful indicator of the adequacy of oxygen delivery.在過去數(shù)年中，許多論文已經(jīng)降低了對使用中心靜脈氧飽和度的熱情，但對于氧供充足與否而言，其仍然為非常有用的指標之一。12理解臨床血流動力學The combination of inexpensiveIt is helpful to understand the modern incarnation of the Fick Equation of the relationship

23、 between oxygenconsumption, cardiac output, arterial oxygen content, and mixed venous oxygen content.這有助于理解Fick方程的現(xiàn)代演變，即有關氧耗量、心輸出量、動脈血氧含量以及混合靜脈氧含量之間的關系。This algebraicrearrangement emphasizes that the mixed venous saturation is adequate only when the delivery of oxygen to the peripheral tissues is we

24、ll matched to their needs:這種代數(shù)重組過程強調，只有當輸送到外周組織的氧與外周組織的氧耗契合良好時，混合血氧飽和度才充足： SvO2 (CvO2) = CaO2 VO2 Qt(Where SvO2 is the mixed venous oxygen saturation, CvO2 is the mixed venous oxygen content, CaO2 is the arterial oxygen content, VO2 is the oxygen consumption, and Qt is the cardiac output)(SvO2為混合靜脈氧

25、飽和度，CvO2為混合靜脈氧含量，CaO2為混合靜脈氧含量，VO2為氧耗，Qt為心輸出量）13理解臨床血流動力學It is helpful to understand thImportantly, as oxygen delivery to the tissues falls, oxygen extraction rises, and continues until the tissues are nolonger able to extract more oxygen. When this happens, crisis ensues.重要的是，當組織氧供下降時，氧解離增加，直至組織再沒有能

26、力攝取更多的氧。當發(fā)生這種情況時，危機就隨之而來。14理解臨床血流動力學Importantly, as oxygen deliverIn the left figure, oxygen extraction increases as oxygen delivery decreases. When the tissues reach the limits of their ability to extract oxygen (the critical extraction ratio ERc), the critical oxygen delivery has been reached (Qo2

27、c), and further decreases in oxygen delivery will be associated with a decline in oxygen consumption.15理解臨床血流動力學In the left figure, oxygen extArterial hypoxemia, anemia, hyper-metabolism, and a low cardiac output all lower the mixed venous and central venous saturation.動脈低氧血癥、貧血、高代謝以及低心排都可降低混合靜脈和中心靜

28、脈氧飽和度。Increasingly, practitioners are utilizing protocols which include as one of their endpoints a central venous oxygen saturation above a certain level (Ladakis, Rivers).越來越多的臨床醫(yī)師開始參照指南，包括將一定水平的中心靜脈氧飽和度作為復蘇終點之一。This strategy of forward defense is in part based on the increasing recognition that h

29、ypotension is a relatively late indicator of shock, and that resuscitating a patient to a marginal blood pressure may leave them with an inadequate physiologic reserve.這一“早期防御”策略部分基于將低血壓視為休克相對晚期的指標的認同感增加，而且復蘇患者達到臨界血壓，其可能處于不適當?shù)纳韮洹?6理解臨床血流動力學Arterial hypoxemia, anemia, hyFrom Physics : V = I x R Sub

30、stituting produces: BP Pra = Qt x SVR物理學：V = IR 替代公式：BP Pra = QtSVRHypoperfusion (shock) can arise from: - low cardiac output - low SVR - the combination of a low cardiac output and high SVR灌注不足（休克）可由以下因素引起：低心排低SVR低排高阻（低心排和高體循環(huán)阻力）17理解臨床血流動力學17理解臨床血流動力學18理解臨床血流動力學18理解臨床血流動力學As demonstrated by the abo

31、ve figure, we can superimpose the Starling curve from above left upon the venous return curve from the above right and generate a graphical representation of the state of the circulation. The cardiac output is represented by the Y projection of the intersection of these curves, and the CVP we measur

32、e clinically is represented by the X projection of the intersection of these curves.將左側的Starling曲線圖和靜脈回心血量圖疊加，生成循環(huán)狀態(tài)的圖示。心排出量則是通過這些曲線的交叉點Y軸的投影表示的，臨床監(jiān)測的CVP通過曲線交叉點的X軸投影表示的。19理解臨床血流動力學As demonstrated by the above fDiastolic dysfunction is a generally underappreciated and very important contributor or ca

33、use of shock states.舒張功能不全為一項被普遍低估、卻非常重要的休克狀態(tài)的誘因或病因。In animal models of hemorrhagic shock, even small reductions in pleural pressures from reduced levels ofPEEP or reduced respiratory rates can produce dramatic improvements in survival (Herff).在失血性休克動物模型中，即使由PEEP水平降低或呼吸頻率減少導致胸腔壓力細微的下降都可使動物模型的存活狀況顯著改

34、善（Herff）。This data, coupled with similar data from animal models of CPR, are generating increased interest in ventilation strategies associated with the lowest possible airway pressures in patients with shock.基于該數(shù)據(jù)及從心肺腦復蘇動物模型中得到的相似數(shù)據(jù)，人們越來越對以盡可能最小的氣道壓力對休克患者進行通氣的模式感興趣。20理解臨床血流動力學Diastolic dysfunction

35、is a genBedside Assessment of the patient with shock休克患者的床旁評估The following questions constitute an orderly way to assess the patient with inadequate circulation:1. Is the Cardiac Output Reduced?2. Is the heart “too full”?3. What doesnt fit?以下幾個問題形成了一個有序的方法，可用于循環(huán)容量不足患者的評估： 心輸出量是否減少 心臟是否“太滿” 什么方法不適合Is

36、 the cardiac output reduced?No Vasodilated ShockYes Hypovolemic shock, Cardiogenic Shock, or Obstruction to Venous Return心輸出量是否減少不是血管擴張性休克（血流分布性休克）是的低血容量性休克、心源性休克、靜脈回心受阻21理解臨床血流動力學Bedside Assessment of the patiThe above figure demonstrates the sentinel feature of vasodilated or high cardiac output s

37、hock:the wide pulsepressure.血管擴張性或高心排性休克的標志性特征為：脈壓差大。Patients with vasodilated shock almost invariably have a pulse pressure which is greater than half of their systolic pressure, whereas patients with low cardiac output shock typically have a pulse pressure which is substantially lower than normal.

38、對于血管擴張性休克患者，脈搏壓力大于收縮壓的一半的狀態(tài)幾乎始終存在，總體而言，低心排性休克患者的脈壓則低于正常人。A patient with a blood pressure of 80/30 almost certainly has vasodilated shock,whereas a patient with a blood pressure of 80/60 will have one of the causes of low cardiac output.當患者血壓為80/30 mmHg時，幾乎可以確定存在血管擴張性休克，而血壓為80/60 mmHg時，則為引起低心輸出量的原因之一

39、。22理解臨床血流動力學The above figure demonstrates 理解臨床血流動力學培訓課件Differential Diagnosis of Vasodilated Shock:- Sepsis, Sepsis, Sepsis- Systemic Inflammatory Response Syndrome (SIRS) (e.g. pancreatitis)- Hepatic failure- Anaphylaxis- Adrenal insufficiency- AV fistula- Others血管性休克的鑒別診斷：-膿毒血癥，敗血癥，菌血癥-全身炎癥反應綜合征SI

40、RS（如胰腺炎）-肝衰竭-過敏反應-腎上腺功能不全-動靜脈血管瘺-其他24理解臨床血流動力學Differential Diagnosis of VasoIs the heart too full? If the cardiac output is low, the differentiation of hypovolemic and cardiogenic shock is accomplished through the review of pertinent historical, physical examination, and laboratory data.Historical i

41、nformation is often compelling in its support for the conclusion that hypovolemia is the cause of an unacceptable circulation.如果合并低心輸出量，低血容量性休克和心源性休克的鑒別可通過相關病史的回顧、體格檢查和實驗室檢查來實現(xiàn)。既往信息常常在得出低血容量為導致循環(huán)不穩(wěn)定的原因這一結論時才引起人們的注意。25理解臨床血流動力學Is the heart too full?25理解臨床血流Causes of Hypovolemia: - Hemorrhage- insensi

42、ble losses- redistribution to extravascular space - GI losses - renal losses- vasodilation (venodilation) 引起低血容量休克的原因：-出血-意識喪失-血管外腔再分布-血糖指數(shù)下降-腎損傷-血管損傷Supportive of Cardiogenic Shock:- jugular venous distention- extra heart sounds- pulmonary edema in association with narrow PP - signs or symptoms of

43、myocardial ischemia - new heart murmurs- cardiomyopathy or myocarditis心源性休克的支持依據(jù)：-頸靜脈怒張-額外心音-和窄脈壓有關的肺水腫-心肌缺血的標志和癥狀-新的心臟雜音-心肌梗死和心肌炎26理解臨床血流動力學Causes of Hypovolemia: Su Cardiogenic shock is most readily assessed with echocardiography. The differential diagnosis of cardiogenic shock includes acute LV i

44、nfarction, acute on chronic LV failure, RV infarction, RV failure from some cause of increased pulmonary vascular resistance, and previously undiagnosed valvular lesions such as aorticstenosis, mitral stenosis, and mitral regurgitation. 通過超聲心動圖最容易對心源性休克進行評估。心源性休克的鑒別診斷包括急性左心梗死、慢性左心衰急性期、右心梗死、由某些因素造成肺血

45、管阻力增加導致的右心衰以及先前未確診的瓣膜疾病，如主動脈瓣狹窄、二尖瓣狹窄和二尖瓣關閉不全。Echocardiography has supplanted the Swan-Ganz catheter as the method of choice for assessing the patientwith suspected cardiogenic shock.超聲心動圖已經(jīng)取代Swan-Ganz導管成為評估疑似心源性休克患者的首選。27理解臨床血流動力學 Cardiogenic shock is most reReasons for this include increasing reco

46、gnition that practitioner understanding of how to utilize data from a Swan-Ganz catheter is generally poor (Iberti), difficulty demonstrating that these catheters improve outcomes (Sandham), and increasing acceptance that central venous gases correlate well with mixed venous gases.其原因包括進一步認識到醫(yī)師對如何應用

47、Swan-Ganz導管知識的貧乏，導管難以改善預后的闡釋以及對中心靜脈氣體與混合靜脈氣體之間的良好的相關性的認同性增加。28理解臨床血流動力學Reasons for this include increPerhaps most importantly, echocardiographic studies have documented surprisingly poor correlation between filling pressures as measured by invasive monitors and left ventricular end-diastolic volume

48、(Osman). Evidence impeaching the use of central venous pressure measurements continues to accumulate, and is now being summarized in colorful review articles(Marik).可能更重要的是，超聲心動圖研究已經(jīng)證明，行有創(chuàng)監(jiān)測獲得的充盈壓與左心室舒張末容積之間的相關性極差。關于中心靜脈壓監(jiān)測的質疑證據(jù)也不斷積累，并被總結成了豐富多彩的綜述文章。As a consequence of these insights, experts are in

49、creasingly advocating the use of arterial pulse pressurevariation as a guide to administering fluid, with a difference of 10-15% with respiration strongly associated with a favorable response to fluid administration (Michard, 2005).鑒于以上觀點，專家越來越主張將動脈脈壓變異度作為液體管理的一項指南，當呼吸相關性動脈脈搏壓力變異度10%15%時，液體治療往往會產(chǎn)生比較

50、好的反應。29理解臨床血流動力學Perhaps most importantly, echoThe two most commonly used metrics are Systolic Pressure Variation (SPV) and Delta Pulse Pressure (PP). Systolic Pressure Variation is easier to estimate from conventional monitors, but is slightly inferior to delta Pulse Pressure (also referred to as Pu

51、lse Pressure Variation PPV).最常用的兩種監(jiān)測指標為收縮壓變異度（SPV）和PP。收縮壓變異度更容易通過應用傳統(tǒng)監(jiān)護儀來評估，但略遜于PP（也被稱為，脈搏壓力變異PPV）。SPV and/or PPV outperform both CVP and Pcwp as predictors of volume responsiveness in septic patientsand cardiac patients, including patients undergoing OPCAB and post-op CABGs (Auler, Hofer, Kramer).對

52、于敗血癥和心臟病患者，包括進行OPCAB以及CABG術后的患者，將SPV和/或PPV作為容量反應的預測指標優(yōu)于CVP和PCWP。30理解臨床血流動力學The two most commonly used metNewer monitors intended for use in either the ICU or the OR incorporate software that facilitates the evaluation of these parameters.通過應用ICU或OR中的較新的監(jiān)護儀整合了便于分析這些參數(shù)的軟件。Other technologies, including

53、 Stroke Volume Variation (SVV)(Lahner, Machare-Delgado), and the PICCO derived Intrathoracic Blood Volume Index (ITBV) are being explored as alternatives to the CVP inpredicting volume responsiveness (Muller), but do not yet match the performance of either PPV or SPV. There is agrowing literature re

54、garding the use of pulse-oximeter derived plethysmography as a less-invasive alternative toSPV or PPV(e.g. Pizov)作為CVP預測容量反應能力的替代指標，其他技術（包括每博量變異度（SVV）以及由胸內血容量指數(shù)(ITBV）演變而來的PICCO）正在研發(fā)中，但其性能不如PPV或SPV。31理解臨床血流動力學Newer monitors intended for usSystolic pressure variation is useful as a guide to the manage

55、ment of the patient in shock in another way:patients with minimal or no variation in the blood pressure and pulse pressure are very unlikely to respond to volume administration.另一方面，對休克患者進行管理時，收縮壓變異度為一個非常有用的指標：患者血壓和脈壓出現(xiàn)極小或無變異時，幾乎不可能對容量治療作出反應。The initial efforts to resuscitate such patients should th

56、erefore be directed at pharmacologicor mechanical interventions, which are much more likely to be effective. Because this strategy minimizes theunnecessary administration of fluid to critically ill patients, it may improve outcomes.因此，對此類患者進行復蘇時，最初的努力應著眼于使用藥物或機械方法干預，這樣或許會更有效。由于該方案最大限度的減少了對危重患者實施的不必要

57、的液體治療，因而可能會改善預后。32理解臨床血流動力學Systolic pressure variation isWhat doesnt fit?Most patients with hypovolemic shock, LV shock, and sepsis respond to appropriate therapy. Failure to respond should raise red flags, and drive an evaluation for obstructive shock.大多數(shù)低血容量性休克、LV休克（左心室相關性休克）以及敗血癥患者對恰當?shù)闹委熅蟹磻?。對于無反

58、應者，應該停止治療并評估是否發(fā)生阻塞性休克。Obstructive shock is shock caused by an obstruction to venous return. Obstructions to venous return are often insidious. While volume resuscitation and therapy with vasoactives might produce a transient minor improvement in the circulation, the definitive treatment consists of

59、relieving the obstruction if this is possible.阻塞性休克由靜脈回心受阻引起。靜脈回心受阻一般較為隱匿。雖然容量復蘇和應用血管活性藥物治療可能會產(chǎn)生短暫輕微的循環(huán)改善，但如果可能，恰當?shù)闹委煈敯p輕靜脈回心阻力。33理解臨床血流動力學What doesnt fit?33理解臨床血流動力學Causes of Obstructive Shock (Obstructions to Venous Return)- pericardial effusion- restrictive pericardium- tension pneumothorax- high levels of PEEP or intrinsic PEEP- massive pleural effusion- abdominal tamponade- venous occlusion (clot, air, tumor, pregnancy)- atrial occlusion (clot, air, tumor)阻塞性休克的病因（靜脈回心受阻）：-心包積液-心包縮窄-高PEEP