C:\Documents and Settings\ja2\Dokumenty\DEMONSTRACE\krevní tlak u koně001.jpg Blood pressure measurement •The system pressure values are, for technical reasons, dependent on: •Measuring method used •Non-invasive methods: •auscultatory •oscillometry •ultrasound •photopletysmography •Invasive methods •indirect – Swan-Ganz´s catheter •direct – catheter with a pressure sensor at the end •Methodology •Clinical measurement – in ambulance - practitioner •Home measurement •24hour ambulatory blood pressure monitoring •Austrian Von Basch • „aneroid sfygmomanometr“ •With baloon on wrist •1876 • • • • • • • •Italian physician •Riva Rocci •„mercury sfygmomanometr“ •With cuff on the arm •1896 •Palpatory method •Auscultatory method • • •Russian army surgeon •Nikolaj Korotkoff •1904 • •„mercury sfygmomanometr“ •The cuff on the arm, •stethoscope in the area of the elbow Auscultatory methods •based on detection of Korotkoff phenomenons •„gold standard“ •with comparison on intra-arterial measurement of blood pressure – we will find: lower values for SBP and higher values of DBP • /this is only technical systemic mistake – does not matter/ •According a guidelines for diagnostic of arterial hypertension: we diagnose arterial hypertension: repeated blood pressure increase above 140/90mmHg, demonstrated at least in two out of three measurements using the auscultation method in the clinical setting Oscillometric method •Author: Mr. Marey – the first describe on 1876 •It has been repeatedly demonstrated that the oscillation of BP in the sphygmomanometric cuff is measured during its gradual discharge - the point of maximum oscillation corresponds to the mean arterial pressure measured invasively •Oscillations begin approximately around systolic pressure values and continue after deflation of the cuff = both systolic and diastolic pressure is estimated only indirectly based on empirical derived algorithms •Advantage: Less susceptible to external noise Disadvantage: definitely unreliability in physical activity - distortion by motion artifacts + susceptible to low-frequency mechanical vibrations Ultrasound method •The device includes an ultrasonic vibration generator and an ultrasonic sensor - placement via the brachial artery and under the sphygmomanometric cuff When deflate the cuff, it induces a systolic movement of the arterial wall that causes the Doppler phase shift in the transmitted ultrasound signal; diastolic BP is calculated by a significant reduction in arterial wall motions •Other variant: systolic BP based on blood flow detection - in newborns and small children Digital photoplethysmography •Continuously blood pressure measurement - „beat to beat“ – from digital artery • •Profesor Jan Peňáz – Department of Physiology – Masaryk university in Brno - patent 1969 • •Disadvantage: can not be used in conditions with peripheral vasoconstriction (shock states, vasoneurosis, diabetic angiopathy) 05 •We need than pressure in the cuff corresponded to the pressure of the digital artery •Method: photopletysmography •Recorded photoelectric plethysmogram •The new term: Transmural pressure – Pt (the pressure across the wall of the artery) •BP, Pc (pressure in cuff), Pt •We estimated: BP=Pc - - - Pt=0 - - - photoplethysmogram registered the highest amplitude of oscilation --- we measure the MAP •Step by step increase of Pc, in the moment of the highest amplitude – feed-back loop started for obtained(keeping) the constant volume of the finger Penaz patent •He used the signal from the photocell to control the external cuff pressure and that to keep the finger volume unchanged. This has achieved that pressure in the cuff monitors blood pressure in the artery. Record of breathing and waves in circulatory parameters (Peňáz´s photoplethysmomanometr) obr11 Finapres (Ohmeda, USA) IMG_0869 P2290051 Invasive measurement of blood pressure •The most accurate measurement method of BP – BUT HIGH RISK: - difficult accessibility, risk of infection diseases Usage: BP monitoring in critical states (coronary units, intensive care units); in more complex therapeutic procedures •Indirect - Swan-Ganze catheter - hollow tube, on the vessel side with a hole, the other side connected to the sensor - filled with physiological solution - transfer of pressure changes from the vessel's light towards the sensor – inaccurate •Direct – special sensor – special microsensor on the vessel side - the blood pressure signal is transmitted from it • up-to-date catheters - signal transmission via fiber optics • Important for the diagnosis of all forms of pulmonary hypertension Methodology •Clinical statement •In keeping with a good practice is still auscultation method able to report reliable results • •We must rely on white-coat hypertension versus masked hypertension in some patients There is always higher BP in the case of BP measurement by physician and lower values measured by nurse or technician Methodology 2 •„Home“ blood presure measurement •Advantage: measurement by patients, elimination of white-coat hypertension effect, measurement in long period •Disadvantage: technical problem, correct measurement by patient •Classic oscillometry method – cuff on the arm •Attention on location of measurement on the wrist - in the vertical position - pressure above 15-20 mmHg higher than on the arm, even when in the heart position the SBP is higher by 2-3mmHg than on the arm •Finger position cuff (non digital photoplethysmography) - Higher values of 4 mmHg than on the arm (another characteristic of the pulse curve in the finger artery) •Values at home measurements are always lower than in the clinical setting – Hypertension society recommendation: BP higher than 135/85mmHg - are increased ! Methodology 3 •24 hour ambulatory blood pressure monitoring •Advantage: an overview of absolute values and variability in time-defined periods (! but still intermittent measurement!) •Oscillometric method •Information: SBP, DBP, pulse pressure, mean arterial pressure - profile of absolute values at monitored intervals; average and standard deviation for the period under review; % of the blood pressure parameters above the specified upper limit; calculation of different indexis; determination of variability of blood pressure fluctuation •The number of BP increases in more than 40% of all values in either on night – or day-time interval – dg: arterial hypertension • ABPM values are lower than clinical values - recommendations: • normal: below 135/85 daily and night under 120/70; 24 hour diameters 130/80 mmHg C:\Documents and Settings\ja2\Dokumenty\DEMONSTRACE\ABPM 1002.jpg C:\Documents and Settings\ja2\Dokumenty\DEMONSTRACE\ABPM 2003.jpg Methodology 4 •Continuously blood pressure measurement •Beat to beat record by Penaz method •BP is dynamic parameter • variability of fluctuation of heart rate and blood pressure – regulation by baroreflex – cooperation both parts of autonomic nervous system (symphathetic and parasymphathetic part) •Necessary component in clinical tests - head up table test (on inclined plane) and BP dysregulation in young subjects - dif.dg syncope •BP regulation research - maneuvers – Valsalva etc. ... .. •BP measurement in extreme situations: supersonic airplane pilots – overload condition, the cosmic program – weightlessness condition etc. Blood pressure in children C:\Documents and Settings\ja2\Dokumenty\LUHAČOVICE\grafy002.jpg Age influence on blood pressure in man and female Fölsch et al., Patologická fyziologie, Grada 2003 For children aged 1 to 13 years/aged ≥13 years •Normal BP: <90th percentile // <120/ <80 mmHg •Elevated BP: ≥ 90th percentile to <95th percentile//120/ <80 to 129/ <80 mmHg •or 120/80 mmHg to <95th percentile (whichever is lower) •Stage 1 HTN: : ≥ 95th percentile to <95th percentile+12 mmHg//130/80 to 139/89 mmHg •Or 130/80 to 139/89 mmHg (whichever is lower) •Stage 2 HTN: ≥ 95th percentile +12 mmHg// ≥140/90 mmHg •Or ≥140/90 mmHg (whichever is lower) •Flynn JT, Kaelber DC, Baker-Smith CM, Blowey D, Carroll AE, Daniels SR, et al., for the Subcommittee on Screening and Management of High Blood Pressure in Children. Clinical practice guideline for screening and management of high blood pressure in children and adolescents. Pediatrics. 2017;140(3):e20171904. https://doi.org/10.1542/peds.2017-1904. https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3d_HTML.gif https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3c_HTML.gif https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3a_HTML.gif https://static-content.springer.com/image/art%3A10.1007%2Fs11906-017-0780-8/MediaObjects/11906_2017 _780_Tab3b_HTML.gif Blood pressure •Immediately after birth – high blood pressure: •Stress after delivery, increase concentration of catecholamine and cortizol •After 1st day …….. 70/50 mmHg: •Open of pulmonary and intestine circulation •During pubertas: •Development of regulatory mechanism •Stimulation of external world •Newborn 80/46 mmHg 10.6/6.1 kPa •3 years 100/67 13.3/8.9 •10-11 years 111/58 14.8/7.7 •13-14 years 118/60 15.7/8.0 Blood presure measurement in newborn and children •Korotkoff method – for children over 1 year – use a correct size of cuff • •In the newborns, auscultation phenomena are poorly audible - there may be an underestimation of SBP • •better use the ultrasound method of the blood flow detector •The size of cuff • •Body weight age size of cuff •1 500 g newborn 2.5 cm • 5 kg 3 month 4.5 cm •10 kg 15 month 6 cm •30 kg 9 year 7.5 cm •more than • 30 kg 10 and more years 12 cm Specific features measurement • Pregnant women •Physiological profile of pregnancy - decrease of BP with increase in cardiac output and large decrease of peripheral resistance = special hyperkinetic conditions - Korotkoff phenomena we auscultated even after deflation of the cuff - diastolic BP we estimated in IV phase of Korotkoff phenomena • •Elderly people with atherosclerosis - poor compressibility of the artery wall by a compression cuff - we need to inflate more - so we measure falsely higher SBP values - pseudohypertension • •Obese persons – using the right size of the cuff !!!!! using a standard cuff – overstocking of SBP •Dynamic physical exercise - auscultation method may underestimate SBP by 15 mmHg, during recovery phase - overstatement of up to 30mmHg SBP; DBP less frequently but falsely low - better use for DBP measurement reading from phase IV of Korotkoff sounds Actual blood pressure values are dependent on: •factors that are conditioned by the organism •on the measurement method • •in which conditions the measurements are performed (methodology) • •even on accuracy and reliability of instruments (technical page - necessary tests and calibration of pressure device / 1 year) • •THIS MUST BE ALLOWED TO CONSIDER AT THE MEASUREMENT IN CLINICAL PRACTICE THANK YOU FOR YOUR ATTENTION