JJM MEDICAL COLLEGE                                                       DAVANGERE                                 DEPART...
1. Indirectbp measurement2. Directbp measurement3. Intra operative ECG4. Central venous pressure<br />
     “ Not everything that counts can be counted. And not everything that can be counted counts.” - Albert Einstein<br /> ...
Blood pressure<br />
“Of all the procedures done in clinical medicine that have important consequences, measurement of blood pressure is likely...
Indirect measurement<br />
“It should be clearly recognized that arterial pressure cannot be measured with precision by means of sphygmomanometers”  ...
<ul><li>Introduced in italy in 1886 by an physician named Riva-Rocci</li></li></ul><li>
Reasons for inaccuracy<br /><ul><li>Faulty methods and short comings
Inherent variability of blood pressure
White coat effect – this is not important for anaesthetists</li></li></ul><li>Influence of bladder size<br /><ul><li>The l...
If the bladder is too small for the size of the arm, the pressure measurements will be falsely elevated
A cuff that is larger than needed will not produce spurious pressure recordings</li></ul>Am J Cardiol1989;63:983-985<br />
dimensions<br />
DO NOT “MISCUFF”<br />Miscuffingis considered the most common source of errors in the blood pressure measurement<br />
  Rapid assessment<br />
auscultatory method<br />
“It is what we think we know already that often prevents us from learning”<br />                                          ...
The sounds<br /><ul><li>The first korotkoff sound corresponds to the systolic pressure but the value is lower than IBP
The disappearance fifth korotkoff sound corresponds to the diastolic pressure but the value is higher than IBP</li></li></...
Lowest hearing frequency – 16 Htz</li></ul>“  A situation exists where the human ear being used to measure BP is, at best,...
Some habits cannot be changed<br /><ul><li>The bell of the stethoscope is a low frequency transducer
The diaphragm is designed to detect high frequency sounds
Since korotkoff sound is in the lower frequency BELL should be used for BP measurement</li></ul>Recommendations for blood ...
SBP decreases by 8 mm<br />                              DBP increases by 5 mm<br />                              SBP incr...
Deflation rate<br /><ul><li>Recommended rate is 2 to 3 mm per sec
In case of slow heart rate it is 1 mm per pulse
When the rate is greater than 3 mm per sec</li></ul>Systolic is underestimated and diastolic is over estimated <br />
“Shock”ing  truth<br /><ul><li>Korotkoff sounds are generated by blood flow
low flow states can diminish theintensity of these sounds.
When this occurs, the sounds may not be heard at first and this will result in falsely low recordings for the systolic blo...
Oscillometric method<br /><ul><li>The oscillometric method uses the principle of plethysmography
When an inflated cuff is placed over an artery, the pulsatilepressure changes in the artery will be transmitted to the inf...
The periodic changes in cuff pressure are then processed electronically to derive a value for the mean, systolic, and dias...
     Belief ?<br /><ul><li>The distinction between pressure and flow is important to recognize because there is a tendency...
It is most evident in the popularity of pressor or vasoconstrictor agents in the management of clinical shock.
 In this setting, an increase in blood pressure is often assumed to indicate an increase in systemic blood flow</li></li><...
When vascular impedance (i.e., compliance and resistance) is increased  the velocity of the flow wave is decreased.
Thus when vascular impedance is abnormal, the arterial pressure is not a reliable index of blood flow.</li></li></ul><li>D...
Modified allens test<br /><ul><li>Elevate arm above heart
Have pt open and close fist several times
Tightly clench fist
Occlude radial and ulnar a
Lower hand, open fist, release ulnar a
Color return within 7 sec = OK</li></li></ul><li>Hand position<br />
Angle of entry<br />
Advancement of guide wire<br />
The waveform<br />
“Mean”arterial pressure<br />      1. The mean pressure is the true driving pressure for   peripheral blood flow.<br />   ...
These reflected waves originate from vascular bifurcations and from narrowed blood vessels.
Amplification of the systolic pressure is particularly prominent when the arteries are noncompliant, causing reflected wav...
Resonant Systems<br /><ul><li>Vascular pressures are recorded by fluid-filled plastic tubes that connect the arterial cath...
This fluid-filled system can oscillate spontaneously, and the oscillations can distort the arterial pressure waveform
What is an under damped system ?
What is an over damped system ?</li></li></ul><li>Flush test <br />
Systolic pressure variation in predicting fluid responsiveness<br />
electrocardiography<br />
Lead placement<br />
Modified 3 leads systems<br />
Colour blind<br />
Trouble shooting<br /><ul><li>Place leads in the correct position.
Avoid placing leads over bony areas. In patients with large breasts, place the electrodes under the breast.
Apply tincture of benzoin to the electrode sites if the patient is diaphoretic. The electrodes will adhere to the skin bet...
The surgical cauteryearthing pad should be away from the leads to prevent signal distortion.</li></li></ul><li>Know thy pa...
calibration<br />         A standard signal of 1milli volt should moves the stylus vertically 1 cm<br />
  artifacts<br />
Waves and<br />
<ul><li>Standard lead l is perpendicular to lead  AVF
Standard lead llis perpendicular to lead  AVL
Standard lead lll is perpendicular to lead  AVR</li></li></ul><li>Axis identification (the right way)<br />
Heart rate in odd situations<br />
Prognostic value of routine preoperative ECG<br />“ Due to improvement in accuracy of clinical cardiac risk factors to ide...
<ul><li>The magnitude and extent of Q waves provide a crude estimateof LVEF and are a predictor of long-term mortality.
Although the optimal time interval between obtaining a 12-leadECG and elective surgery is unknown, general consensus sugge...
Most modern electrocardiographic monitors allow the operator a choice of several bandwidths. </li></ul>                (1)...
Use of intra operative ECG<br /><ul><li>Myocardial infarction
Arrhythmias
Conduction defects</li></li></ul><li>Vector pattern<br />
ST segment pattern<br />
Criteria for Acute Myocardial Ischemia<br /><ul><li>1 mm (0.1 mV) or more of horizontal or down-sloping ST-segment depression
rapidly up-slopingST segment that is also depressed less than 1.5 mm is considered normal
T-wave changes not accompanied by significant ST-segment displacement rarely signify myocardial ischemia</li></li></ul><li...
Evolution of MI<br />
Automated ST monitoring<br />
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Electrocardiography,cvp,blood pressure

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this is my college presentation and i hope it doesnt bore you. i have used abstract clipart with literal meaning of the text. send your remarks

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Electrocardiography,cvp,blood pressure

  1. 1. JJM MEDICAL COLLEGE DAVANGERE DEPARTMENT OF ANAESTHESIOLOGY<br />SEMINAR ON<br />Blood pressure , ECG , Central venous pressure<br /> CHAIRPERSON PRESENTED BY<br /> DR.RAVISHANKAR . R B DR.RAVIVARMA.D<br /> PROFESSOR PG IN ANAESTHESIA<br /> DEPT OF ANAESTHESIA<br />
  2. 2. 1. Indirectbp measurement2. Directbp measurement3. Intra operative ECG4. Central venous pressure<br />
  3. 3. “ Not everything that counts can be counted. And not everything that can be counted counts.” - Albert Einstein<br /> adapted from THE ICU BOOK by PAUL MARINO<br />
  4. 4. Blood pressure<br />
  5. 5. “Of all the procedures done in clinical medicine that have important consequences, measurement of blood pressure is likely the one that is done most haphazardly” – kaplan,M.D<br />adapted from THE ICU BOOK by PAUL MARINO<br />
  6. 6.
  7. 7. Indirect measurement<br />
  8. 8. “It should be clearly recognized that arterial pressure cannot be measured with precision by means of sphygmomanometers” – American heart association 1951<br />
  9. 9. <ul><li>Introduced in italy in 1886 by an physician named Riva-Rocci</li></li></ul><li>
  10. 10. Reasons for inaccuracy<br /><ul><li>Faulty methods and short comings
  11. 11. Inherent variability of blood pressure
  12. 12. White coat effect – this is not important for anaesthetists</li></li></ul><li>Influence of bladder size<br /><ul><li>The length of the bladder should be at least 80% of the circumference of the upper arm and the width of the bladder should be at least 40% of the upper arm circumference
  13. 13. If the bladder is too small for the size of the arm, the pressure measurements will be falsely elevated
  14. 14. A cuff that is larger than needed will not produce spurious pressure recordings</li></ul>Am J Cardiol1989;63:983-985<br />
  15. 15. dimensions<br />
  16. 16. DO NOT “MISCUFF”<br />Miscuffingis considered the most common source of errors in the blood pressure measurement<br />
  17. 17. Rapid assessment<br />
  18. 18.
  19. 19.
  20. 20.
  21. 21. auscultatory method<br />
  22. 22. “It is what we think we know already that often prevents us from learning”<br /> - Claude Bernard<br />
  23. 23. The sounds<br /><ul><li>The first korotkoff sound corresponds to the systolic pressure but the value is lower than IBP
  24. 24. The disappearance fifth korotkoff sound corresponds to the diastolic pressure but the value is higher than IBP</li></li></ul><li>Problems with human ear<br /><ul><li>Best hearing frequency- 200 to 4000 Htz
  25. 25. Lowest hearing frequency – 16 Htz</li></ul>“ A situation exists where the human ear being used to measure BP is, at best, basically deaf to some sound it should be detecting”<br />adapted from Am J Cardiol 1989;63:983-985<br />
  26. 26. Some habits cannot be changed<br /><ul><li>The bell of the stethoscope is a low frequency transducer
  27. 27. The diaphragm is designed to detect high frequency sounds
  28. 28. Since korotkoff sound is in the lower frequency BELL should be used for BP measurement</li></ul>Recommendations for blood pressure measurement. Circulation 2005;111:697-716<br />
  29. 29. SBP decreases by 8 mm<br /> DBP increases by 5 mm<br /> SBP increases by 8 mm<br /> DBP decreases by 5 mm<br />
  30. 30. Deflation rate<br /><ul><li>Recommended rate is 2 to 3 mm per sec
  31. 31. In case of slow heart rate it is 1 mm per pulse
  32. 32. When the rate is greater than 3 mm per sec</li></ul>Systolic is underestimated and diastolic is over estimated <br />
  33. 33. “Shock”ing truth<br /><ul><li>Korotkoff sounds are generated by blood flow
  34. 34. low flow states can diminish theintensity of these sounds.
  35. 35. When this occurs, the sounds may not be heard at first and this will result in falsely low recordings for the systolic bloodpressure.</li></ul>Cohn JN. Blood pressure measurement in shock. JAMA 1967; 119:118.<br />
  36. 36. Oscillometric method<br /><ul><li>The oscillometric method uses the principle of plethysmography
  37. 37. When an inflated cuff is placed over an artery, the pulsatilepressure changes in the artery will be transmitted to the inflated cuff, producing similar changes in cuff pressure.
  38. 38. The periodic changes in cuff pressure are then processed electronically to derive a value for the mean, systolic, and diastolic blood pressures.</li></li></ul><li>The accuracy of oscillometric blood pressure measurements is disturbingly low.<br />J clinMonit1990;6:284–298<br />
  39. 39. Belief ?<br /><ul><li>The distinction between pressure and flow is important to recognize because there is a tendency to equate pressure and flow in certain situations
  40. 40. It is most evident in the popularity of pressor or vasoconstrictor agents in the management of clinical shock.
  41. 41. In this setting, an increase in blood pressure is often assumed to indicate an increase in systemic blood flow</li></li></ul><li><ul><li>Ejection of the stroke volume from the heart is accompanied by a pressure wave and a flow wave.
  42. 42. When vascular impedance (i.e., compliance and resistance) is increased the velocity of the flow wave is decreased.
  43. 43. Thus when vascular impedance is abnormal, the arterial pressure is not a reliable index of blood flow.</li></li></ul><li>Direct measurement<br />
  44. 44.
  45. 45. Modified allens test<br /><ul><li>Elevate arm above heart
  46. 46. Have pt open and close fist several times
  47. 47. Tightly clench fist
  48. 48. Occlude radial and ulnar a
  49. 49. Lower hand, open fist, release ulnar a
  50. 50. Color return within 7 sec = OK</li></li></ul><li>Hand position<br />
  51. 51. Angle of entry<br />
  52. 52.
  53. 53. Advancement of guide wire<br />
  54. 54.
  55. 55. The waveform<br />
  56. 56. “Mean”arterial pressure<br /> 1. The mean pressure is the true driving pressure for peripheral blood flow.<br /> 2. The mean pressure does not change as the pressure waveform moves distally<br /><ul><li>Heart rates faster than 60 beats/minute, which are common in critically ill patients, lead to errors in the estimated mean arterial pressure.</li></li></ul><li>Systolic amplification <br /><ul><li>The increase in systolic pressure in peripheral arteries is the result of pressure waves that are reflected back from the periphery .
  57. 57. These reflected waves originate from vascular bifurcations and from narrowed blood vessels.
  58. 58. Amplification of the systolic pressure is particularly prominent when the arteries are noncompliant, causing reflected waves to bounce back faster</li></li></ul><li>transducer<br />
  59. 59. Resonant Systems<br /><ul><li>Vascular pressures are recorded by fluid-filled plastic tubes that connect the arterial catheters to the pressure transducers.
  60. 60. This fluid-filled system can oscillate spontaneously, and the oscillations can distort the arterial pressure waveform
  61. 61. What is an under damped system ?
  62. 62. What is an over damped system ?</li></li></ul><li>Flush test <br />
  63. 63. Systolic pressure variation in predicting fluid responsiveness<br />
  64. 64. electrocardiography<br />
  65. 65. Lead placement<br />
  66. 66. Modified 3 leads systems<br />
  67. 67. Colour blind<br />
  68. 68. Trouble shooting<br /><ul><li>Place leads in the correct position.
  69. 69. Avoid placing leads over bony areas. In patients with large breasts, place the electrodes under the breast.
  70. 70. Apply tincture of benzoin to the electrode sites if the patient is diaphoretic. The electrodes will adhere to the skin better.
  71. 71. The surgical cauteryearthing pad should be away from the leads to prevent signal distortion.</li></li></ul><li>Know thy paper<br />
  72. 72. calibration<br /> A standard signal of 1milli volt should moves the stylus vertically 1 cm<br />
  73. 73. artifacts<br />
  74. 74. Waves and<br />
  75. 75. <ul><li>Standard lead l is perpendicular to lead AVF
  76. 76. Standard lead llis perpendicular to lead AVL
  77. 77. Standard lead lll is perpendicular to lead AVR</li></li></ul><li>Axis identification (the right way)<br />
  78. 78. Heart rate in odd situations<br />
  79. 79.
  80. 80. Prognostic value of routine preoperative ECG<br />“ Due to improvement in accuracy of clinical cardiac risk factors to identify patients who are at increased risk of peri operative cardiac events, the routine use of ECG in all patients is of questionable value”<br />noordzij et al: Am J Cardiol 2006;97:1103-1106<br />
  81. 81. <ul><li>The magnitude and extent of Q waves provide a crude estimateof LVEF and are a predictor of long-term mortality.
  82. 82. Although the optimal time interval between obtaining a 12-leadECG and elective surgery is unknown, general consensus suggeststhat an ECG within 30 days of surgery is adequate for thosewith stable disease in whom a preoperative ECG is indicated.</li></li></ul><li>Electrographic monitoring systems<br /><ul><li>All electrocardiographic monitors use filters to narrow the signal bandwidth in an attempt to reduce environmental artifacts and improve signal quality
  83. 83. Most modern electrocardiographic monitors allow the operator a choice of several bandwidths. </li></ul> (1) a diagnostic mode with a bandwidth of 0.05 to 130 Hz <br /> (2) a monitoring mode with a bandwidth of 0.5 to 40 Hz <br /> (3) a filter mode with a bandwidth of 0.5 to 20 Hz.<br />
  84. 84.
  85. 85. Use of intra operative ECG<br /><ul><li>Myocardial infarction
  86. 86. Arrhythmias
  87. 87. Conduction defects</li></li></ul><li>Vector pattern<br />
  88. 88. ST segment pattern<br />
  89. 89. Criteria for Acute Myocardial Ischemia<br /><ul><li>1 mm (0.1 mV) or more of horizontal or down-sloping ST-segment depression
  90. 90. rapidly up-slopingST segment that is also depressed less than 1.5 mm is considered normal
  91. 91. T-wave changes not accompanied by significant ST-segment displacement rarely signify myocardial ischemia</li></li></ul><li>The best lead<br /><ul><li>When two leads can be monitored simultaneously, lead II is the best compliment to lead V5 because it significantly improves the sensitivity for ischemia and usually reveals the p wave for dysrhythmia diagnosis</li></li></ul><li>Different “avatars” <br />
  92. 92. Evolution of MI<br />
  93. 93. Automated ST monitoring<br />
  94. 94.
  95. 95.
  96. 96.
  97. 97.
  98. 98.
  99. 99.
  100. 100.
  101. 101.
  102. 102.
  103. 103.
  104. 104.
  105. 105.
  106. 106.
  107. 107.
  108. 108.
  109. 109.
  110. 110.
  111. 111.
  112. 112.
  113. 113.
  114. 114. Central venous pressure<br />
  115. 115. <ul><li>1929 - Forssmann placed the first central venous cannula in a human
  116. 116. 1956 - Seldinger first described his guide wire directed technique for central vein cannulation
  117. 117. 1969 – English first described Cannulation of Internal jugular vein (IJV)</li></li></ul><li>physiology<br />
  118. 118. Pit falls<br />
  119. 119.
  120. 120. He who works with his hands is a laborer. He who works with his head and his hands is a craftsman. - St. Francis of Assisi<br />adapted from THE ICU BOOK by PAUL MARINO<br />
  121. 121. Vascular Catheters<br /><ul><li>Vascular catheters are made of polymers impregnated with barium or tungsten salts
  122. 122. Catheters designed for short-term cannulation are usually made of polyurethane
  123. 123. Catheters designed for prolonged use are made of a silicone polymer</li></li></ul><li>
  124. 124. Multipurpose catheter<br />
  125. 125. Indication for central cannulation<br />
  126. 126. Why subclavian ?<br />1993;21:1118–1123.<br />
  127. 127. Subclavian vein<br />
  128. 128. Internal jugular<br />
  129. 129. Ultrasound-Guided Central Venous Cannulation<br />
  130. 130. complications<br />Vascular injury<br />Venous air embolism<br />Pneumothorax<br />Arrhythmias<br />Pulmonary embolism<br />Infection<br />
  131. 131. There are two methods of CVP monitoring<br /><ul><li>manometer system: enables intermittent readings and is less accurate than the transducer system
  132. 132. transducer system : enables continuous readings which are displayed on a monitor.</li></li></ul><li>Body Position<br /><ul><li>The zero reference point for venous pressures in the thorax is a point on the external thorax where the fourth intercostal space intersects the mid- axillary line
  133. 133. It corresponds to the position of the right and left atrium when the patient is in the supine position.
  134. 134. It is not a valid reference point in the lateral position</li></li></ul><li>End-Expiration ?<br /> Intravascular pressures should be measured at the end of expiration, when they are equivalent to the transmural pressure<br /> in PEEPwhts the problem ?<br />
  135. 135.
  136. 136. Spontaneous Variations<br /><ul><li>Like any physiologic variable, vascular pressures in the thorax can vary spontaneously, without a change in the clinical condition of the patient.
  137. 137. In general, a change in CVP or wedge pressure of less than 4 mm Hg should not be considered a clinically significant change.
  138. 138. Normal CVP in an awake, spontaneously breathing patient ranges between 1 and 7 mm Hg.</li></li></ul><li>CVP waveform abnormalities<br />
  139. 139. REFERENCES :<br /> <br />1. MILLERS ANAESTHESIA 7th edition<br />2. THE ICU BOOK- paulmarino 3rd edition<br />3. SCHAMROTH ECG<br />4. Am J Cardiol 1989;63:983-985<br />5. Recommendations for blood pressure measurement. Circulation 2005;111:697-716<br />6. Cohn JN. Blood pressure measurement in shock. JAMA 1967; 119:118.<br />7. noordzij et al: Am J Cardiol 2006;97:1103-1106<br />

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