Measurement & Monitoring PDF

– Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Measurements and Clinical Monitoring Measurement & Monitoring A. Prof...

– Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Measurements and Clinical Monitoring Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Tarik Saber Sarhan By A Professor of Anesthesiology, Intensive Care, and Pain Management, Faculty of Medicine, Al-Azhar University A Professor of Emergency Medicine and Intensive Care, IMC, KSA A Professor of Anesthesiology and Intensive Care, AMC, KSA Head of MBBCh Program, Faculty of Medicine, Al-Azhar University Director of Medical Education and Training Unit Microsoft Certified Innovative Educator and trainer Mendeley International Advisor BASIC UNITS International System of Units Objectives You will be able to Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan History  Initially, measurements were related to commonly available objects; thus, in early Egyptian times length was related to the width of the finger (the digit) or to the distance from the elbow to the fingertips (the cubit)  ‫األوزان اليت ذكرت يف القرآن‬ ‫الصاع ‪:‬جمع أصواع أو أصوع وجاء بلفظ صواع أو صيعان ‪ ،‬ويذك ّر و يؤن ّث ‪ ،‬و يعادل كيلوان وخمسة وثلاثون جراما ً ‪ ،‬ورد‬ ‫ل ب َيعرٍ و ََن نا بِه ِ َ َيمٌ ﴾ [الآية‪]٧٢ :‬‬ ‫الصواع في قوله تعالى في سورة يوسف ‪﴿ :‬قالوا نَفقِد ُ صُواعَ الملَِكِ و َلم َِن جاء َ بِه ِ حِم ُ‬ ‫القنطار ‪:‬ستة أمنان ‪ ،‬والمن يساوي شرعا ً ‪ 180‬مثقالا ً ‪ ،‬ورد في قوله تعالى ‪﴿ :‬و َِإن َن ر َدت ُم ُ است ِبدا َ‬ ‫ل َ َوج م َكانَ َ َوج‬ ‫[النساء‪]٢٠ :‬‬ ‫و َآتَيتٌُ ِإحداه َُّن ق ِنطار ًا‬ ‫ل ذ ََّرة ش ًَّرا ي َر َه ُ [الزلزلة‪]٨-٧ :‬‬ ‫المثقال ‪:‬ورد في قوله تعالى ‪﴿ :‬فَم َن يَيعم َل م ِثقا َ‬ ‫ل ذ ََّرة خ َرٍ ًا ي َر َه ُ ۝ وَم َن يَيعم َل م ِثقا َ‬  ‫األوزان اليت ذكرت يف القرآن‬ ‫[يوسف‪]٢٠ :‬‬ ‫الدرهم ‪ :‬ورد في قوله تعالى ‪﴿ :‬و َشَر َوه ُ بِثمََن بَخس د َراهِم َ م َيعدود َة‬ ‫ك‬ ‫الدينار ‪:‬مثقال شرعي ‪ ،‬ورد في قوله تعالى ‪﴿ :‬وَم ِنه ُم م َن ِإن ت َأم َنه ُ بِدينار لا يُؤ َدِه ِ ِإلَي َ‬ ‫[آل عمران‪]٧٥ :‬‬ ‫الذراع ‪:‬عرف الذراع بين الناس كوحدة لقياس الطول وهي طوليا أقل من المتر الذي نعرفه‬ ‫‪ ،‬وطول الذراع الشرعي يساوي ‪ ٤٩‬سنتيمتر‪ ،‬ورد ذكر الذراع في قوله تعالى ‪﴿ :‬ث َُّم في‬ ‫سِلسِلَة ذ َري ُها سَبيعونَ ذِراعًا فَاسل ُكوه ُ [الحاقة‪]٣٢ :‬‬  For example, in Britain alone, there have been at least six different ‘pounds’ ranging from 350 g (Tower pound) to 500 g (metric pound). The currency, a ‘pound sterling’, was originally derived from the value of a mass: a Tower pound of silver. This made it difficult for, in particular, the wealthy members of the population to measure and quantify their goods, leading to errors in transactions and fraud. It was as a result of this that the committee of the Académie des Sciences was convened by Louis XVI of France and his national assembly, to develop a unified form of measurement. This resulted in the production of the units of length (metres) and mass (kilogram) that were quantified and standardized Systems of Measurement Two main systems of measurement were used The Imperial or British system: based on the Foot (length), Pound (mass), Second (time) (FPS). Disadvantages: the interrelationship between its units is not systematic e.g., one mile = 1760 yards while one foot = 1/3 yard. Systems of Measurement The Metric or French system: based on Centimeter (length). Gram (mass), and Second (time) (CGS that were later replaced by Meter, Kilogram, and Second (MKS). The system that we use today initially started its development in France during the French Revolution in the 1790s. Units of Measurement Two main systems of measurement were used In 1960, further refinement and extension of this system occurred to be the Systeme Internationale d'Unites (SIU). This occurred in an international conference on weights and measures held at Sevres; a suburb of Paris. Units of Measurement Two main systems of measurement were used The replacement of the imperial by the metric system has proceeded in different countries. All units relevant to medical practice have become metric, but the change to SI has been patchy and has not vet been established in many countries. The SI system The SI system is sometimes called the MKS (meter, kilogram, second) system, because these are the standard units of length, mass, and time upon which derived quantities, such as energy, pressure, and force, are based. An older system is called the CGS (centimeter, gram, second) system. Systeme Internationale d'Unites SIU Systeme It consists of seven Internationale base units and many derived units d'Unites The Seven SI Base Units Here are the seven SI base units and their abbreviations: Unit Symbol Measure Second s Time Meter Or Metre m Length Kilogram kg Mass Ampere A Electric Current Kelvin K Thermodynamic Temperature Mole mol Amount Of Substance Candela cd Luminous Intensity  A) The Seven Base SI Units: Definitions of the Seven Base Units The meter (m) (the unit of length): The length equal to a specific number of wavelengths of the orange light of specified emission, in a vacuum, from the krypton-86 atom. The meter (m) (the unit of length) Initially the meter, was supposed to be a distance equal to 1/10 000 000 of the distance along the Earth's surface between the pole and equator.  Later on, the standard meter was the length of a metal bar made of platinum and iridium and kept at Sevres. The meter (m) (the unit of length)  In 1960, as the need for greater accuracy has become apparent, the International Bureau of The meter (m) Weights and Measures at Sevres (the unit of turned towards standards length) present in natural phenomena, as these can be measured by scientists anywhere in the world (length of wavelengths emitted from krypton-86). The meter (m) (the unit of length): The length equal to a specific number of wavelengths of the orange light of specified emission, in a vacuum, from the krypton-86 atom. The kilogram (kg) (the unit of Mass) Equal to the mass of the international prototype kilogram, a platinum- iridium cylinder preserved at the International Bureau of Weights and Measures at Sevres, Paris. The kilogram (kg) (the unit of Mass): The platinum-iridium alloy is used because it has a thermal coefficient of expansion close to zero i.e., its mass does not change by temperature. The second (the unit is the duration of a specific number of periods of the radiation (frequencies) of the structure transitions in the of time) atoms of caesium-133. The ampere (A) (the unit of electric current) The ampere (A) (the unit of electric current): is the amount of electric current which when flows down each of two parallel conductors placed one meter apart in a vacuum, would generate between these conductors a force equal to 2 x 107 newton per meter of length. N.B.: It represents a flow of 6.24 x 1018 electrons per second past some point  The kelvin (abbreviation The kelvin (K) K), less commonly called the degree Kelvin (symbol, o K), is the Standard International ( SI ) unit of thermodynamic temperature. The kelvin (K) 1/273.16 of the thermodynamic temperature of the triple point of water (the point at which solid, liquid, and gaseous phases are in equilibrium). K = °C + 273.15 °C = K − 273.15 The mole (m) (The unit of the amount of substance): is the amount of substance of a system which contains as many elementary entities (atoms, molecules, ions, electrons) as there are atoms in 0.012 kg of carbon 12. The mole represents the gram molecular weight of the substance Each sample contains 6.02 × 1023 molecules or formula units—1.00 mol of the compound or element. The mole (m) Average Atomic Mass Element Molar Mass (g/mol) Atoms/Mole (amu) C 12.01 12.01 6.022×1023 H 1.008 1.008 6.022×1023 O 16.00 16.00 6.022×1023 Na 22.99 22.99 6.022×1023 Cl 33.45 33.45 6.022×1023 Check Your Learning According to nutritional guidelines from the US Department of Agriculture, the estimated Referring to the periodic table, average requirement for dietary potassium is 4.7 the atomic mass of K is 39.10 g. What is the estimated average requirement of amu, and so its molar mass is potassium in moles? 39.10 g/mol. Discussion point Mole Day is an unofficial holiday celebrated by scientists. The date is October 23 and the holiday begins at 6.02 am. Why has this date and time been chosen? The candela (cd) The unit of luminous intensity in the International System of Units (SI) Defined in terms of the brightness of light (looked at perpendicularly) of a small area of molten platinum at a given temperature and pressure B) The Derived Units All the derived units are derived from the seven base units Dicimal Multiples and Submultiples (Fractions) SI PREFIX MULTIPLIERS Non-SI Units Temporarily Retained These are non-SI units, but are still in common use in medical practice. Non-SI Units Temporarily Retained Pressure, the effect of a force applied to a surface, is a derived unit. The unit of pressure in the SI system is the pascal (Pa), defined as the force of one newton per square meter: Non-SI Units Temporarily Retained The bar and psi (Pounds per square inch) as units of pressure of compressed gases. Non-SI Units The mmHg (millimeter of Temporarily mercury) (torr) as a unit of blood Retained pressure. Non-SI Units The cm H2O as a unit of central venous Temporarily pressure (CVP). Retained The calorie (cal) as a unit of heat energy. Non-SI Units Temporarily Retained The minute (min), hour (h), and day (d) as units of time.  Advantages of the (SIU) Simplification: the Decimalization: decimal basis of SI The SI system is a Standardization: decimal multiples system makes universal system of the use of one and submultiples of calculations very units. Thus, it is standard unit for any unit can be It is a coherent system used in almost each physical derived by adding of units, i.e., it has a set every country in the quantity. one standard prefix of fundamental units, world. to the unit. from which all other units can be derived. Drug Concentration Concentration Propofol 1 % amp Bupivacaine 0.5 % How many milli-grams in one ml? Our basic assumption 1 cm3 Weights Occupies Water 1g 1ml  It means that From this we can say 1 gram of drug 100mls of Water has that a 100% solution in 1ml of volume a weight of 100g would be  1% is a This solution common drug There are So this is also would have = 10mg per dilution. A 1% 1000mg in 1 1000mg per 1g per 1ml (the same as gram 100ml 100mls 1:100)  Diluted Drugs could be written in the following ways by a prescriber: Please give 10mls of 1 percent subcutaneous Lignocaine  Lignocaine 1% is commonly used for topical local anaesthesia A 1% solution literally means there is 1gram per 100mls So, if there is 1g per 100mls there is also 1000mg per 100mls If we divide this down there will be 10mg in 1ml The vial pictured above has 5ml (so there is 50mg in this 5ml in this vial)  ‫واخر دعوانا أن الحمد لل ّه رب العالمين‬ ‫وصل اللهم وسلم وبارك على سيدنا محمد وعلى آله‬ ‫وصحبه كلما ذكرك وذكره الذاكرون وكلما غفل عن‬ ‫ذكرك وذكره الغافلون عدد خلقك ورضا نفسك وزنة‬ ‫عرشك ومداد كلماتك‬ COMMON CONVERSION FACTORS There are a few other points of correctness worth considering Unit symbols do not have a plural form, i.e. ‘70 cms’ is incorrect, it is ‘70 cm’. 70 cm 70 cms There are a few other points of correctness worth considering Whilst unit symbols are typically an abbreviation (cm for centimetre, for example), they are not followed by a full-stop except at the end of a sentence, i.e. ‘150 cm tall’, not ‘150 cm. tall’. 150 cm 150 cm. tall tall There are a few other points of correctness worth considering Values should always be specified numerically and with symbols for units, i.e. ‘15 A’, not ‘fifteen 15 A fifteen amps’, ‘fifteen A’ or amps’, ‘15 amps’. ‘fifteen A’ or ‘15 amps’. There are a few other points of correctness worth considering There should always be a space between the value and the unit with the exception of angles. Therefore, even though the symbol is the same, be careful with degrees; a temperature is 15 °C (not 15°C) but an angle is 45°, not 45 °. 15 °C 15°C There are a few other points of correctness worth considering Unit symbols do not have a plural form, i.e. ‘70 cms’ is incorrect, it is ‘70 cm’. Whilst unit symbols are typically an abbreviation (cm for centimetre, for example), they are not followed by a full-stop except at the end of a sentence, i.e. ‘150 cm tall’, not ‘150 cm. tall’. Values should always be specified numerically and with symbols for units, i.e. ‘15 A’, not ‘fifteen amps’, ‘fifteen A’ or ‘15 amps’. There should always be a space between the value and the unit with the exception of angles. Therefore, even though the symbol is the same, be careful with degrees; a temperature is 15 °C (not 15°C) but an angle is 45°, not 45 °. Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Measurement & Monitoring Clinical Monitoring A. Prof. Dr. Tarik Sarhan By Tarik Saber Sarhan A Professor of Anesthesiology, Intensive Care, and Pain Management, Faculty of Medicine, Al-Azhar University A Professor of Emergency Medicine and Intensive Care, IMC, KSA A Professor of Anesthesiology, and Intensive Care, AMC, KSA Head of MBBCh Program, Faculty of Medicine, Al-Azhar University Director of Medical Education and Training Unit Microsoft Certified Innovative Educator and trainer Mendeley International Advisor Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Introduction Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Monitoring is a human right. By Anesthetist relies on his/her natural senses to monitor the patient. Simple aids as stethoscope & sphygmomanometer help the anesthetist and may safe the patient. It is important to use monitor for Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Safety. By Conduct of anesthesia. ICU practice. Assessment of critical conditions. Research work. What’s monitor ? Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Monitor is a Latin By word “monere” which means “to warn” Any monitor consists of Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Sensor Electrodes e.g.: ECG Transducers By Processing Device : System for data collection, amplification, modification and interpretation. Display/Recorder Analogue Digital Graph Simple classification of monitoring devices Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Class sensor data collect. interpret. By I Human Human Human II Device Human Human III Device Device Human IV Device Device Device Invasive vs non-invasive Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Non-invasive e.g. ECG By Minimally invasive e.g. I.V cannula Invasive e.g. Arterial cannula Highly invasive e.g. Brain, heart cannula Limitation of monitoring Measurement & Monitoring A. Prof. Dr. Tarik Sarhan 1) Delay. 2) Danger. By 3) Decrease skill. 4) Doubt of results. 5) Distracting set up. Standards for Basic Anesthetic Monitoring Measurement & Monitoring A. Prof. Dr. Tarik Sarhan ASA Standard Monitoring By ASA STANDARD I Measurement & Monitoring A. Prof. Dr. Tarik Sarhan 1.“Qualifiedanesthesia personnel shall be present in the room By throughout the conduct of all general anesthetics, regional anesthetics, and monitored anesthesia care.” STANDARD II-V Measurement & Monitoring A. Prof. Dr. Tarik Sarhan During all anesthetics, the patient’s oxygenation, By ventilation, circulation and temperature shall be continually evaluated.  Pulse Oximetry (ASA Standards … And …) Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Capnography (Standard ……) By Electrocardiogram (Standard.......) Noninvasive Blood Pressure (Standard ……) Temperature (Standard ……)  Pulse Oximetry (ASA Standards II And IV) Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Capnography (Standard III) By Electrocardiogram (Standard IV—circulation) Noninvasive Blood Pressure (Standard IV) Temperature (Standard V) Pulse Oximetry (ASA Standards II And IV)  Objectives  Understand oximetry assesses oxygen saturation of hemoglobin Measurement & Monitoring  Understand oximetry can show effectiveness of interventions A. Prof. Dr. Tarik Sarhan  Know oximetry is a routine vital sign  Know procedures of application and reading oximetry Determine sights for application of oximetry By   Describe possible troubleshooting  Understanding that hemoglobin reflects light differently with and without oxygen  Objectives Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Introduction Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Introduction Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Pulse oximeters measure how much By of the hemoglobin in blood is carrying oxygen (oxygen saturation). Pulse Oximetry Measurement & Monitoring A. Prof. Dr. Tarik Sarhan measure the percentage of hemoglobin with By oxygen attached Pulse Oxygen oximeter saturation over 95% = normal simple, rapid, safe, and noninvasive Pulse oximeters are in common use because Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Non-invasive Simple to use By Cheap to buy and use Cost-effectiveness over ABG Can be very compact Require no warm-up time Detects hypoxaemia earlier than you using your eyes to see cyanosis. Pulse oximeter Measurement & Monitoring A. Prof. Dr. Tarik Sarhan technology By PHYSICAL PROPERTIES USED IN PULSE OXIMETRY  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Pulse oximetry uses light to By work out oxygen saturation. Light is emitted from light sources which goes across the pulse oximeter probe and reaches the light detector. Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan If a finger is placed in between the light source and the light detector, the light will now have to pass through the finger to.reach the detector Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Part of the light will be absorbed by the finger and the part not absorbed reaches the light detector. By Physical property: Amount of light absorbed is proportional to the concentration of the light absorbing Measurement & Monitoring A. Prof. Dr. Tarik Sarhan substance By Hemoglobin (Hb) absorbs light. The amount of light absorbed is proportional to the concentration of Hb in the blood Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Physical property Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Different "colors" of light have their own wavelength.  Physical property Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Physical property Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Now let us see the absorbance graph of oxy Hb and the absorbance graph of deoxy Hb together so you can compare them. Note how each of them absorbs light of different wavelengths very differently.  Physical property Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By One is a red light which has a wavelength of approximately , 660 nm. The other is an infrared light which has a , wavelength of940 nm. Physical property : oxyhemoglobin absorbs more infrared light than red light & deoxyhemoglobin absorbs more red Measurement & Monitoring A. Prof. Dr. Tarik Sarhan light than infrared light By All light is composed of waves. The distance between the "tips" of the waves is equal to the wavelength.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By The pulse oximeter uses two lights to analyze hemoglobin. Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  blood Pulse oximeters measure pulsatile Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Skin and other tissues also absorb some light. The potential to get confused because it doesn't know how much light is absorbed by blood and how much is absorbed by the tissues surrounding blood.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Fortunately, there is a clever solution to the problem. The pulse oximeter wants to only analyse arterial blood, ignoring the other tissues around the blood. Luckily, arterial blood is the only thing pulsating in the finger. Everything else is non pulsating. Any "changing absorbance" must therefore be due to arterial blood.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By On the other hand, the pulse oximeter knows that any absorbance that is not changing , must be due to non pulsatile things such as skin and other "non arterial" tissues.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By So the final signal picture reaching the pulse oximeter is a combination of the "changing absorbance" due to arterial blood and the "non changing absorbance" due to other tissues.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By The pulse oximeter is able to use some clever mathematics to extract the "changing absorbance" signal from the total signal.After the subtraction, only the "changing absorbance signal" is left, and this corresponds to the pulsatile arterial blood. In this way, the pulse oximeter is able to calculate the oxygen saturation in arterial blood while ignoring the effects of the surrounding tissues.  % Saturation Deoxy−Hb Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Clinical Considerations Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Value one of the most essential monitors for routine use in anesthesia and intensive care. Measurement & Monitoring A. Prof. Dr. Tarik Sarhan measures O2 saturation of Hb in arterial blood. By measures heart rate. gives an idea about tissue perfusion by pulse waveform. High signal waves >>> high pulse pressure e.g., peripheral vasodilatation or high cardiac output. Low signal waves >>> low pulse pressure e.g., peripheral vasoconstriction or low cardiac output PLETH trace (Pleth) Plethysmographic Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Pulse oximeters often show the pulsatile By change in absorbance in a graphical form. This is called the "plethysmographic trace " or more conveniently, as "pleth."  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan The pleth is an extremely By important graph to see. It tells you how good the pulsatile signal is  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan The pleth is an extremely important By graph to see. If the quality of the pulsatile signal is poor then the calculation of the , oxygen saturation may bewrong.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan The pleth is an extremely important graph to see. By A poor pleth tracing can easily fool the computer into wrongly calculating the oxygen saturation. As human beings, we like to believe what is good, so when we see a nice saturation like 99 , % we tend to believe it, when actually the patients actual saturation may be much lower. So always look at pleth first, before looking at oxygen saturation. Never look only at oxygen saturation! Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan SOURCES OF ERROR Problems with pulse oximeter Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Pulse Oximetry Erroneous readings may result from Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Bright ambient light (cover clip) Patient motion By Poor perfusion Nail polish Venous pulsations Abnormal hemoglobin  Problem of too much ambient light Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By If the ambient light is too strong the LED light signal gets "submerged" in ,.the noise of the ambient light. This can lead to erroneous readings  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Therefore, it is important to minimise the amount of ambient light falling on the detector. One can try and move away strong sources of room light. One can also try and cover the pulse oximeter probe and finger with a cloth etc.  Problem of movement Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Which such a small signal, it is easy to see how errors can occur. Pulse oximeters are very vulnerable to motion, such as a patient moving his hand. As the finger moves, the light levels change dramatically. Such a poor signal makes it difficult for the pulse oximeter to calculate oxygen saturation.  Measurement & Monitoring Extremely low SpO2 with no dyspnea. A. Prof. Dr. Tarik Sarhan   A 93 year-old man was hospitalized for a non-ST elevation myocardial infarction after an episode of gastroenteritis. He lived independently, shopping for himself and driving his car without incident. He was a lifetime non-smoker and drank one beer per week. His past medical history was notable for essential tremor, hypothyroidism, benign prostatic hypertrophy, stage 4 chronic renal disease but not on dialysis, glaucoma, and venous thromboembolism three years ago. On examination, he was in no acute distress and looked much younger than stated age. His temperature was 97.1 °F, pulse 80 beats per minute, blood pressure 125/60 mmHg, respiratory rate 16 per minute, and a SpO2 of 93% on baseline supplemental oxygen of 2 L/min. Exam only notable for a mild resting hand tremor. By  He underwent a dipyridamole-99mTc-sestamibi nuclear perfusion study. Upon returning from the stress test to his room, vital signs taken by a nursing student using a wall-mounted pulse oximeter revealed a pulse rate of 228 beats per minute and SpO2 reading of 73%. He was placed on high flow oxygen by face mask and a Rapid-Response Medical Team was called. Due to the persistently low SpO2, he was placed on 100% oxygen using a non-rebreather mask but the SpO2 remained between 40 and 70% and the heart rate on the monitor remained above 200 beats per minute. His measured blood pressure was 135/80 mmHg. He denied any chest pains or any change in his breathing. He appeared nervous but was not cyanotic. His lungs were clear to auscultation. An EKG rhythm strip was obtained and shows a baseline heart rate of 60 beats per minute with smaller spikes between the QRS complexes, best seen in lead II (Fig. 4). These low voltage spikes are due to his hand tremor and the measured SpO2 with the finger probe was considered to be spuriously low due to the hand tremor. This assumption was consistent with the observation that the pulse reading of ≥200 beats per minute by the oximeter was similar to the tremor rate on the EKG. Using a different pulse oximeter in which the probe was placed on his forehead, the pulse rate was 65 beats per minute and the simultaneous SpO2 was 100% while breathing high flow oxygen through a non-rebreather mask. For confirmation, an arterial blood gas obtained on 100% non-rebreather mask revealed a pH of 7.36, PaCO2 of 41 mmHg, PaO2 of 302 mmHg, and a SaO2 of 100%. At the time that the arterial blood gas was obtained, the simultaneous SpO2 reading using the finger probe was 48%. In retrospect, auscultation of the heart beat and/or palpation of a radial pulse revealing that the heart rate was not >200 beats per minute would have quickly indicated that the pulse oximetry reading of the SpO2 was inaccurate.  Problem of electromagnetic interference Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Electrical equipment such as surgical diathermy emit strong electric waves which may be picked up by the wires of the pulse oximeter. These waves make small currents form in the wires, confusing the pulse oximeter which assumes these currents come from the light detector. During diathermy use, one should be cautious about interpreting pulse oximeter readings.  Problem of poor peripheral perfusion Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By A good peripheral blood flow makes the arteries in fingers nicely pulsatile. As discussed before, it is the pulsatile change in absorbance that is used in the calculation of oxygen saturation.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By When the peripheral perfusion is poor (e.g. in hypotension), the arteries are much less pulsatile. The change in absorbance is therefore less and the pulse oximeter may then find the signal inadequate to correctly calculate oxygen saturation.  Conditions that prevent pulsatile blood flow will negate the use of a pulse oximeter to monitor blood-oxygen saturation. Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Reduced cardiac output Occlusion of the artery upstream of the capillary bed being By monitored (most commonly by a blood pressure cuff) Vasoconstriction, which prevents blood flow into peripheral capillaries. Severe shock can cause loss of pulse oximeter signal and return of the pulse oximeter signal may be the first sign that cardiac output or perfusion is recovering. Problem of Colored dyes and nail polish Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Light-absorbing material, such as dirt or nail polish, on the patient’s body part that the pulse oximeter is on can also be a source of interference. This can be overcome by removing the contaminant, moving the probe, or changing the orientation of the probe side to side, such that the light does not pass through the nail polish. Usually, only blue, purple, black, and metallic nail polishes cause difficulty  Fingernail polish Earlier reports of pulse oximeters noted that Measurement & Monitoring A. Prof. Dr. Tarik Sarhan fingernail polish, particularly black, blue, and green color, can lower SpO2 by up to 10%. More recent studies with newer models of pulse By oximeters found that fingernail polish has only a minor effect on SpO2 readings; i.e., black and brown fingernail polish displayed the greatest reduction in the SpO2 reading but by an average decrease of ≤2% Problem of Colored dyes and nail polish Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By The dye, methylene blue, if in the patients circulation, will artificially lower the displayed oxygen saturation.  Problem of abnormal hemoglobins Measurement & Monitoring A. Prof. Dr. Tarik Sarhan Abnormal hemoglobin can affect pulse oximeter readings. Carbon monoxide combines with hemoglobin to form carboxy hemoglobin By (carboxy Hb). Most pulse oximeters cannot separately detect carboxy Hb. Instead, it considers carboxy Hb as oxy hemoglobin. This is dangerous as carboxy Hb doesn't carry oxygen, and the artificially high oxygen saturation displayed may wrongly reassure everyone. Another abnormal hemoglobin , called methemoglobin causes the , saturation to falsely show readings towards about85% Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  CO toxicity May be due to exposure from a variety of sources including propane- Measurement & Monitoring powered engine, natural gas, automobile exhaust, portable A. Prof. Dr. Tarik Sarhan generators, gas log fireplaces, kerosene heaters, fire smoke, and paint strippers and spray paints as dichloromethane in these products gets metabolized to CO. By The principal pathogenic mechanism of CO poisoning is the strong avidity of CO for Hb (240× greater than O2), forming carboxy-Hb (COHb), reducing the O2 carrying capacity of Hb and precipitating tissue hypoxemia. CO can also impair myoglobin and mitochondrial function; increase guanylate cyclase activation which can lead to vasodilation and hypotension; and augment lipid peroxidation causing microvascular impairment and reperfusion injury.  CO-oximetry Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Measurement & Monitoring When Joe Kiani and Mohamed Diab looked at the same pulse A. Prof. Dr. Tarik Sarhan oximetry signal differently than anyone had before, they created new possibilities. By employing advanced signal processing techniques– including parallel engines and adaptive filters–they believed they By could find the true arterial signal that would allow accurate monitoring of arterial oxygen saturation and pulse rate, even during the most challenging conditions. Signal Extraction Technology®, or Masimo SET®, assumes that both the arterial and venous blood can move and uses parallel signal processing engines–DST®, FST®, SST™, and MST™–to separate the arterial signal from sources of noise (including the venous signal) to measure SpO2 and pulse rate accurately, even during motion.  Measurement & Monitoring A. Prof. Dr. Tarik Sarhan After six years of dedicated and focused research and development, By Masimo SET® debuted in 1995 at the Society for Technology in Anesthesia and won the prestigious Excellence in Technology Innovation Award. Thereafter, skeptical clinicians around the world sought to compare Masimo SET® to the best pulse oximetry technologies other companies had to offer. But in study after study, the signal processing of Masimo SET®consistently resulted in significantly fewer false alarms and true alarm detection. Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Cerebral Oximetry Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Cerebral Oximetry Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Pulse Oximeter Types Finger Tip Hand Held Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By “Table Top” This does not endorse any company, all pictures are intended for educational purposes only Transmission probes oximeter Types of pulse Reflection Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  Pulse oximeter probes can Measurement & Monitoring A. Prof. Dr. Tarik Sarhan be either By Disposable Reusable Sensors for Pulse Oximeters Measurement & Monitoring A. Prof. Dr. Tarik Sarhan By Standard finger sensors Wrap around sticker sensors Wrap around silicone sensors Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan Measurement & Monitoring By A. Prof. Dr. Tarik Sarhan  CAPNOGRAPHY CO2 Monitoring A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Differentiate between oxygenation and ventilation Capnography Define end-tidal CO2 Learning Objectives Identify phases of a normal capnogram Recognize patterns of hypoventilation, hyperventilation and bronchospasm……..etc A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation and Ventilation WHAT IS THE DIFFERENCE? A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation and Ventilation Two completely different and separate functions Oxygenation is the transport of O2 via the Ventilation is the bloodstream to the exhaling of CO2 via cells the respiratory tract Oxygen is required Carbon dioxide is a for metabolism byproduct of metabolism A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation and Ventilation Ventilation Oxygenation (capnography) O2 (oximetry) Cellular Metabolism CO2 A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation Measured by pulse oximetry (SpO2) Noninvasive measurement Percentage of oxygen in red blood cells Changes in ventilation take minutes to be detected Affected by motion artifact, poor perfusion and some dysrhythmias A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation Pulse Oximetry Sensors Pulse Oximetry Waveform A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Ventilation Measured by the end-tidal CO2 Partial pressure (mmHg) of CO2 in the airway at the end of exhalation Breath-to-breath measurement provides information within seconds Not affected by motion artifact, poor perfusion or dysrhythmias A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Ventilation Capnography Lines Capnography waveform A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation versus Ventilation  Monitor your own SpO2 and EtCO2  SpO2 waveform is in the second channel  EtCO2 waveform is in the third channel A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation versus Ventilation  Monitor your own SpO2 and EtCO2  SpO2 waveform is in the second channel  EtCO2 waveform is in the third channel A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation versus Ventilation  Now hold your breath  Note what happens to the two waveforms SpO2 EtCO2 How long did it take the EtCO2 waveform to go flat line? How long did it take the SpO2 to drop below 90%? A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation versus Ventilation How long did it take the SpO2 to drop below 90%? How long did it take the EtCO2 waveform to go flat line? A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Contrasting Pulse Ox with Capnography Pulse oximetry measure oxygen going OUT from the heart Capnography measures what is coming BACK from the periphery Two Different Concepts A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Oxygenation and Ventilation Oxygenation Ventilation Oxygen for Carbon dioxide metabolism from metabolism EtCO2 measures SpO2 measures exhaled CO2 at % of O2 in RBC point of exit Reflects change in Reflects change in oxygenation within ventilation within 5 minutes 10 seconds A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  What is Capnography? ❑“Capnos” = Greek for smoke ❑ From the “fire of life” ➔ metabolism ❑ CO2 is the waste product of metabolism A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnography Basics Carbon Dioxide (CO2) Produced by all living cells Diffused into the bloodstream Transported to the lungs Perfused into the alveoli Exhaled through the airway A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Measuring Exhaled CO2 Colorimetric Capnometry Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Measuring Exhaled CO2 Colorimetric Capnometry Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Measuring Exhaled CO2 Colorimetric Capnometry Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 (EtCO2)  Carbon dioxide can be measured  Arterial blood gas is PaCO2  Normal range: 35-45mmHg  Mixed venous blood gas PeCO2  Normal range: 46-48mmHg  Exhaled carbon dioxide is EtCO2  Normal range: 35-45mmHg A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal Carbon Dioxide Assessment indicates whether carbon dioxide is present in reasonable A amounts between the ET colorimetric tube and carbon ventilation device. After 6-8 positive- dioxide pressure the detector specially-treated paper inside the detector should turn from purple to yellow A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 Assessment Might give a false- positive reading if the patient has carbon dioxide trapped in the stomach Colorimetric Sensitive to extremes of temperature and CO2 humidity; it may be detector less reliable if vomitus or other secretions Limitation get inside it. The paper inside the device degrades over time, resulting in a less reliable A.Prof. Dr.Tarik Sarhan reading. A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 Assessment is a “spot-check” device; you may use it during initial confirmation of ET Colorimetric tube placement, CO2 but you should detector replace it as soon as possible with a Limitation more accurate and reliable quantitative device. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnometer provides quantitative information, in real time, by displaying a numeric reading of exhaled carbon dioxide levels. It uses a special adapter, which attaches between the advanced airway device and ventilation device Because it provides quantitative data, the capnometer is more reliable than the colorimetric co2 detector. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnography provides a graphic representation of exhaled carbon dioxide levels. It performs the same function and attaches in the same way as the capnometer. The two types of capnographers are waveform and digital/waveform. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 (EtCO2) Reflects changes in Ventilation movement of air in and out of the lungs Diffusion exchange of gases between the air-filled alveoli and the pulmonary circulation Perfusion circulation of blood A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 (EtCO2) Monitors changes in Ventilation asthma, COPD, airway edema, foreign body, stroke Diffusion pulmonary edema, alveolar damage, CO poisoning, smoke inhalation Perfusion shock, pulmonary embolus, cardiac arrest, severe dysrhythmias A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 (EtCO2) The cells use the oxygen and produce carbon dioxide (CO2) as a waste product. The CO2 , like the oxygen , goes through a series of steps before it is expelled out of the body. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  End-tidal CO2 (EtCO2) A Capnograph measures how much carbon dioxide is present in the patients breath. They are an essential piece of monitoring and you can find them in areas such as operating rooms, recovery, critical care, wards, and ambulances. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Advantages of capnography Helps assess a variety of problems , from the cell all the way to the breathing equipment Non invasive Rapid Provide continuous measurement Physically small A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Principles Use of Infrared Waves A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Use of infrared waves Capnography uses infrared waves to measure CO2. Infrared waves are waves that are invisible to the eye and have a lower frequency than visible light. The frequency is below red light, which is why it is called “infra” red. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Use of infrared waves Infrared is absorbed by gases that have “two or more different atoms”. Oxygen gas has two atoms which are not different. Therefore, oxygen does not absorb infrared waves. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Use of infrared waves Carbon dioxide gas, unlike oxygen gas, has atoms that are different. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Use of infrared waves Therefore, because carbon dioxide gas has different atoms, it absorbs infrared waves A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Use of infrared waves A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Main stream versus Side Stream A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnograph analyzers are either main stream or side stream. In "main stream" analyzers, the analyzer is directly near the CO2 expired by the patient. The main stream analyser is "attached" to the patient. The analyser is connected to the monitor by long electrical wires. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnograph analyzers are either main stream or side stream In "side stream" analysers, the analyser is away from the CO2 expired from the patient. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnograph analyzers are either main stream or side stream A long narrow tube is connected to the patient end. A pump keeps suctioning a small quantity (e.g. 150 mL per minute) of the patients respiratory gases. This sample of gases flows across the analyser, which is located away from the patient. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnograph analyzers are either main stream or side stream Unfortunately the suction tubing doesn't only suck CO2. It also sucks in expensive anesthetic gases. To avoid wastage of the expensive anaesthetic agents, the sampled gas is returned (green arrows) to the patient anesthetic breathing system. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Main Stream and Side Stream Compared Response time: In side stream analysers, the gases have to travel in the sampling tube before reaching the sensor. This delay (transit time), makes side stream analysers have a slower response time than main stream analysers, which don’t have any delay due to transit time. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Main Stream and Side Stream Compared Weight at patient end: In a side stream analyser, only a thin tube is connected at the patient end. Therefore, the patient end is light. On the other hand, a main stream analyser is located directly at the patient end and is much more bulkier than a simple side stream sampling tube. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Main Stream and Side Stream Compared Monitoring from facemask The thin tube of side stream analysers can be easily attached to the face mask of awake / sedated patients , giving some feedback of their respiration. Main stream analysers are more difficult to use in this way as they are more bulky A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Main Stream and Side Stream Compared Removal of gases: Obstruction: Side stream analysers continuously suction gases for analysis. This can range from The tubing of a approximately 50 – 150 side stream mL/min, and if the patient has small breathes (e.g. neonates analyser can get / paediatrics) the removed blocked or kinked. sample volume may become significant. Main stream Main stream analysers do not remove any gases, so do not analysers do not have this problem. have this problem. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnographic Waveform A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnographic Waveform  Capnograph detects only CO2 from ventilation  No CO2 present during inspiration  Baseline is normally zero C D A B E Baseline A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase I Dead Space Ventilation  Beginning of exhalation  No CO2 present  Air from trachea, posterior pharynx, mouth and nose  No gas exchange occurs there  Called “dead space” A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase I Baseline A B Baseline I Beginning of exhalation A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase II Ascending Phase  CO2 from the alveoli begins to reach the upper airway and mix with the dead space air  Causes a rapid rise in the amount of CO2  CO2 now present and detected in exhaled air Alveoli A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase II Ascending Phase C Ascending Phase Early Exhalation II A B CO2 present and increasing in exhaled air A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase III Alveolar Plateau  CO2 rich alveolar gas now constitutes the majority of the exhaled air  Uniform concentration of CO2 from alveoli to nose/mouth A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase III Alveolar Plateau Alveolar Plateau C D III A B CO2 exhalation wave plateaus A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase III End-Tidal  End of exhalation contains the highest concentration of CO2  The “end-tidal CO2”  The number seen on your monitor  Normal EtCO2 is 35-45mmHg A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase III End-Tidal C D End-tidal A B End of the the wave of exhalation A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase IV Descending Phase  Inhalation begins  Oxygen fills airway  CO2 level quickly drops to zero Alveoli A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnogram Phase IV Descending Phase C D Descending Phase A B IV Inhalation E Inspiratory downstroke returns to baseline A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Capnography Waveform Normal Waveform 45 0 Normal range is 35-45mm Hg A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography Capnography By Dr.Tarik Sarhan , Lecturer , Faculty of Medicine A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Re breathing A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  “shark fin” pattern A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Relaxant Notches A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  "Surgeon Notches"So before you blame the notches on the muscle relaxant, have a look at the chest to see if the surgeons are leaning / pressing on it ! A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography "Cardiac Notches" (cardiac oscillations) A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography   Determination of end-tidal CO2 (ETco2 ) concentration to confirm adequate ventilation is mandatory during all anesthetic procedures. A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  Well that is it for this session on capnography. Hope you enjoyed it and learnt something. See you soon in another session....... A.Prof. Dr.Tarik Sarhan A.Prof. Dr.Tarik Sarhan Capnography Capnography  ‫وصل اللهم وسلم وبارك على سيدنا محمد‬ ‫وعلى اله وصحبه كلما ذكرك الذاكرون‬ ‫وغفل عن ذكره الغافلون‬ ‫واخر دعوانا أن الحمد هلل رب العالمين‬ ‫‪Capnography By Dr.Tarik Sarhan , Lecturer , Faculty of Medicine‬‬ Capnography By Dr.Tarik Sarhan , Lecturer , Faculty of Medicine ABP Monitoring Professor Dr Tarik Sarhan Associate Professor of Anesthesiology, Intensive Care, and Pain Management, Faculty of Medicine, Al-Azhar University A Professor of Emergency Medicine and Intensive Care, IMC, KSA A Professor of Anesthesiology and Intensive Care, AMC, KSA Head of MBBCh Program, Faculty of Medicine, Al-Azhar University Director of Medical Education and Training Unit Microsoft Certified Innovative Educator and Trainer Mendeley International Advisor Al-Azhar International Excellence Bureau AZEX member Introduction Introduction The primary function of the circulatory system is to maintain a constant supply of blood flow to all organs to allow them to maintain aerobic metabolism and their function.  Introduction CVS Resistance As Basic Pump, The Conduits, The Blood Flows Heart Blood Vessels Through The Microcirculation. Introduction The arterial walls are muscular and elastic in the absence of vascular disease. Blood flows through the arteries in a pulsatile fashion as a result of pressure differences between the systolic and diastolic phase Introduction This flow pattern causes the arteries to alternately expand and contract, resulting in the pulse that we can feel with our fingertips Systemic Arterial Blood Pressure  Pumping action of the heart Systemic arterial blood Circulating arterial pressure is created by blood volume Muscle tone of blood vessel walls  Importance of arterial blood pressure Essential Provides for oxygen adequate delivery perfusion for energy of tissues demonds  ABP monitoring Importance Mean ABP reflects cardiac output. Gives an important data about patient cardiovascular status May help to define approach to treatment.  Systolic pressure Diastolic pressure The maximum The lowest pressure pressure within the within the large large arteries when arteries during heart the heart muscle muscle relaxation contracts to propel between beating. blood through the body.  Mean arterial Pulse pressure(PP) pressure (MAP) The difference Calculated from between systolic the systolic and and diastolic diastolic values blood pressure MAP = DAP + 1/3 valu pulse pressure. Mean BP = Diastolic BP + 1/3 (Systolic BP - Diastolic BP) Blood pressure measurement First used during anaesthesia in 1901. Now it is part of the minimum standard of patient monitoring and should be measured in all patients undergoing, and recovering from, general anaesthesia, regional anaesthesia and sedation. In combination with other monitoring, it will help detect 93% of adverse events occurring under anaesthesia. Noninvasive Arterial Blood Pressure Monitoring  Intermittent, non-invasive blood pressure measurement require three key components Inflatable cuff for occluding the arterial supply to the distal limb Method for determining the point of systolic and diastolic blood pressures Method for measuring pressure.  Several Noninvasive technologies have been developed to measure these pulsations and translate them into the blood pressure readings we are familiar with. Pulse detection ① While awaiting a cuff or manometer reading, systolic pressure can be estimated by the location at which a pulse can be palpated For example, if you can only obtain a carotid pulse, then the systolic pressure is at least 60 mm Hg. Similarly, a radial pulse usually begins to be palpable at about 80 mm Hg. Pulse detection Whenever you are palpating a pulse, make sure to use only the tips of your index and middle fingers: the artery in your thumb is large enough that you can mistake your own pulse for that of the patient. Unfortunately, palpation of pulses to estimate blood pressure is unreliable even when performed by experienced providers. ❷ Palpation (Pulse detection) Made practical in 1896, was among the first techniques used for measuring blood pressure noninvasively. In this technique, a blood pressure cuff connected to a manometer is placed around a limb and a distal artery is palpated. The cuff is inflated about 20 mm Hg above the point where the pulse becomes absent. As the cuff is slowly deflated, the manometer reading at the point of pulse return is noted as the systolic pressure. Alternatively, the first “tick” in needle movement on an aneroid manometer or the point at which an SPO2 waveform returns can be noted as the systolic pressure. Palpation The equipment required is simple and inexpensive. This method tends to underestimate systolic pressure, however, because of the insensitivity of touch and the delay between flow under the cuff and distal pulsations. Palpation does NOT provide a diastolic pressure or MAP. Unfortunately, palpation of pulses to estimate blood pressure is unreliable even when performed by health care providers.  ❸ Auscultation The most frequently used method for noninvasive blood pressure monitoring. Auscultation, or “listening,” adds a stethoscope to the cuff and manometer. Auscultation Dr. Nikolai Korotkoff developed this technique and described five distinct sounds that can be heard as a cuff is deflated over an occluded artery. These sounds result from the turbulent return of blood flow in the artery. The first sound : a clear snapping or tapping sound, and the manometer reading is noted as the systolic pressure. The second : a murmur that is heard for most of cuff deflation. The third : a return of a clear, tapping sound. The second and third sounds have no known clinical significance. The fourth sound occurs within 10 mm Hg above the diastolic pressure. The fifth sound is silence as cuff pressure drops below diastolic pressure. This disappearance of sound is recorded as the diastolic pressure.  Auscultation The limitation of this method is dependence on proper technique and the differences in audio and visual acuity among clinicians. Despite these limitations, a cuff, manometer, and stethoscope should be readily available as a backup for automated systems. As an anesthesia technician, you may need to obtain this backup equipment promptly should a monitor fail.  used by the majority of anesthesia and critical care automatic blood presssure monitors. The oscillatory Arterial pulsations create pressure technique variations (oscillations) that are transferred from the cuff to pressure transducers inside the monitor.  Systolic pressures are normally derived from the first significant oscillation detected, The oscillatory while diastolic technique pressures are calculated from the last. MAP is measured at the peak amplitude measured.  Unlike auscultation The techniques, oscillatory oscillometers may have difficulty technique providing accurate readings in patients with arrhythmias.  The speed, accuracy of oscillometric devices have greatly improved, The oscillatory and they have technique become the preferred noninvasive blood pressure monitors worldwide. The oscillatory technique ASA guidelines recommend that the time interval between repeated measurements be no longer than 5 minutes while the delivery of anesthesia or sedation occurs. Some providers prefer a shorter interval such as 3 minutes. In general, should the interval need to be less than 3 minutes for a prolonged period of time, continuous blood pressure measurement through placement use of invasive blood pressure monitoring is indicated.  Pitfalls of cuff systems Relies on a pulse of regular rate and rhythm for accurate measurement. Appropriately sized cuff should be used. Accidental movement of the limb will impair measurement. Limb should be level with heart. The cuff should not be compressed external, i.e. it should not be placed on the lower limb when the patient is placed in the lateral position. It is not possible to measure very low pressures accurately. Pitfalls of cuff systems Tissues, including nerves, can be damaged due to compression. Often painful for the awake patient. The initial reading requires especially high inflation pressures. The cuff  The American Heart Association (AHA) size guidelines  Using the correct cuff size is essential for accurate readings. A cuff that is too small will Cuff Size result in false high readings, and one that is too large will result in false low readings.  Proper cuff placement is also critical for accurate readings. In general, proper placement is approximately 1 inch above the elbow for an arm cuff, 5 inch below Cuff the elbow when using the forearm. Placement Most manufacturers include an “artery” marker in the center of the bladder. Placing this marker directly over the artery to be occluded results in even compression of the artery and helps limit artifact. Doppler Probe When a Doppler probe is substituted for the anesthesiologist’s finger, arterial blood pressure measurement becomes sensitive enough to be useful in obese patients, pediatric patients, and patients in shock  Liquid Manometers Mercury is used as it has 13.6 times the density of water. (A systolic pressure of 120 mm of mercury equates to 1.62 m of water as 7.5 mm Hg = 10 cm H2O).  Aneroid Gauge An aneroid gauge commonly replaces the mercury column as it is more robust and avoids the problems associated with mercury toxicity. They are susceptible to loss of accuracy over time and hence require regular calibration.  Electronic systems A change in air pressure causes movement of a diaphragm. That movement is then detected and displayed electronically. This system is utilized by automated, non-invasive blood pressure measuring systems Troubleshooting Problems will usually present as an inability to obtain a reading. The basic troubleshooting questions to answer are as follows: Is the cuff the correct size? Is the cuff placed correctly? Are all connections tight? Is a member of the surgical team leaning against the cuff? Does the patient have excess muscle movement? Troubleshooting If this sequence does not solve the problem, consider replacing the blood pressure cuff first. >>> not solve the problem>>> replace the tubing that connects the cuff to the monitor >>> Not Solved>>> the problem may be internal to the monitor or related to the physical status of the patient >>> Consider a different cuff location, monitor, or technique. Continuous, invasive blood pressure monitoring  This is the gold standard of blood pressure measurement giving accurate beat-to-beat Invasive Blood information. Pressure Display the information both numerically and graphically. Monitoring In general, systolic pressure will be slightly higher and diastolic pressure slightly lower (5–10 mm Hg), than non-invasive measurements.  Rapid changes in blood pressure are anticipated Cardiovascular Instability It is useful when Large Fluid Shifts Pharmacological Effects Cardiothoracic , vascular,pheo and neurosurgery  Non-invasive blood pressure monitoring is not possible or likely to be inaccurate Obesity Arrhythmias Extensive Burns Long-term measurement in sick patients is required as it avoids the problem of repeated cuff inflation (causing localized tissue damage) and allows repetitive sampling for blood gases and laboratory analysis. Critically ill patients. Elective Hypotension  The basic principle is to provide a solid column of liquid connecting arterial blood to a pressure transducer Requires: Intra-arterial cannula Tubing Transducer Microprocessor Display Screen Mechanism for zeroing and calibration Continuous invasive BP monitors Selection of Artery for Cannulation The radial artery is commonly cannulated because of its superficial location and substantial collateral flow Ulnar artery catheterization is usually more difficult than radial catheterization because of the ulnar artery’s deeper and more tortuous course. The brachial artery is large and easily identifiable in the antecubital fossa The femoral artery is prone to atheroma formation and pseudoaneurysm but often provides excellent access. The femoral site has been associated with an increased incidence of infectious complications and arterial thrombosis. The dorsalis pedis and posterior tibial arteries are some distance from the aorta and therefore have the most distorted waveforms. Technique of Radial Artery Cannulation  Hematoma Bleeding Vasospasm Arterial Thrombosis Skin Necrosis Nerve Damage Infection Necrosis Of Extremities Or Digits Unintentional Intraarterial Drug Injection. Factors associated with an increased rate of complications Prolonged Cannulation Repeated Insertion Attempts The Use Of Larger Catheters In Smaller Vessels The Use Of Vasopressors Hyperlipidemia Clinical Considerations Because intraarterial cannulation allows continuous beat-to-beat blood pressure measurement, it is considered the optimal blood pressure monitoring technique. The quality of the transduced waveform, however, depends on the dynamic characteristics of the catheter–tubing–transducer system. False readings can lead to inappropriate therapeutic interventions.  ‫واخر دعوانا أن الحمد لله رب العالمين‬ ‫وصل اللهم وسلم وبارك على سيدنا محمد وعلى آله‬ ‫وصحبه كلما ذكرك وذكره الذاكرون وكلما غفل عن‬ ‫ذكرك وذكره الغافلون عدد خلقك ورضا نفسك وزنة‬ ‫عرشك ومداد كلماتك‬  ‫بسم هللا الرحمن الرحيم‬ ‫الحمد هلل ‪...‬والصالة والسالم‬ ‫على سيدنا رسول هللا وعلى آله‬ ‫وصحبه ومن وااله‬ Electrocardiogram (ASA STANDARD IV—CIRCULATION) A. Professor Dr Tarik Saber Sarhan  The electrocardiogram (ECG or EKG) Record of the electrical activity of the heart over time. “12-lead” ECG is traditionally used for diagnostic purposes, Most anesthesia and critical care monitoring >>>> either a three-wire or a five-wire. Standard nomenclature RA Right arm RL Right leg LA Left arm LL Left leg V Any of the six cardiac lead positions Three-wire ECG Three-wire ECG Three-wire ECG The most basic of ECG monitoring systems.