PHYSIOLOGY OF BLOOD III Hemoglobine & oxygen delivery ROLE OF HEMOGLOBIN (HB) Transports oxygen in body acido-base buffer 98% of oxygen is bound to Hb allosterically 2% is solved in plasma 135 – 170 g/l in men 120 – 160 g/l in women HEMOGLOBIN • 4 polypeptic chains - subunits 2 chains 2 chains • Each subunit contains 1 heme • 1 hemoglobin binds 1.36ml of O2 • Other chains? Fetal - 22 Adult - 22, 22d (2%) Embryonic - 2z2e, 22e, 2z2 STATE OF THE QUARTER STRUCTURE Deoxyemoglobin – dark red Oxyhemoglobin – light red Reduced hemoglobin ferro- Fe2+ and ferri-hemoglobine Fe3+ Methemoglobin (ferri state)– gray cyanosis Carboxyhemoglobin – light red, CO bound Carbaminohemoglobin – dark red, CO2 bound Other: cyanide (CN-), sulfur monoxide (SO), nitrogen dioxide (NO2), and sulfide (S2-), hydrogen sulfide (H2S) CYANOSIS It is associated with the presence of deoxyhemoglobin in organism Cyanosis – when amount of deHb is more than 50g/l It is about the absolute value What does that mean? Conformational change and O2 binding Oxygen binds to heme and so it brings Fe atom closer to heme, what will lead to conformation change and stabilization of 1 heme unit One Hb subunit will then expose the other subunit (the reason for sigmoid shape curve of oxygen saturation) If one oxygen molecule binds Hb, the second will bind easier HEMOGLOBIN SATURATION CURVE , 2,3 BPG OXYGEN DELIVERY TO ORGANISM O2del=(SVxHR) x Hbconc x 1.36 x SpO2 e.g. HR=70bpm; Hbconc=150g/L; SpO2=98% O2del =(0.07[L] x 70) x 150 [g/L] x 1.36 [ml] x 0.98 = 979,608 ml/min SV – stroke volume [L] HR – heart rate [beats per minute] Hbconc – hemoglobin concentration in blood [g/L] 1,36 – mls of oxygen bound to 1g of hemoglobine SpO2 – % saturation of hemoglobine by oxygen REMEMBER!!!! OXYGEN DELIVERY OXYGEN CONSUMPTION PULSE OXIMETRY pulse oximeters non-invasively measure the arterial oxygen saturation of haemoglobin simple, portable, non-invasive, fast basic examination procedural anaesthesia intensive care & emergency rooms Limitations dyshemoglobinemias hypotension fingernail polish movement visible light interference PULSE OXIMETRY - PRINCIPLE the absorption of light at two different wavelengths by haemoglobin differs depending on the degree of oxygenation of haemoglobin http://www.microchip.com/stellent/idcplg?IdcService =SS_GET_PAGE&nodeId=2723 SpO2 = (O2Hb / (O2Hb + Hb)) x 100% Tremper KK, Barker SJ:Pulse oximetry. Anesthesiology. 1989 Jan;70(1):98-108. PULSE OXIMETRY - PRINCIPLE http://www.microchip.com/stellent/idcplg?IdcService =SS_GET_PAGE&nodeId=2723 Tremper KK, Barker SJ:Pulse oximetry. Anesthesiology. 1989 Jan;70(1):98-108. CONTEC CMS 50D PULSE OXIMETER Arterial saturation of hemoglobin with oxygen value display Heart rate value display ON button Display mode change button Heart rate signal control bar Pletysmograph wave PULSE OXIMETRY Possible waveform readings and interpretation http://www.ebme.co.uk/arts/nellcor/nellcor3.htm OTHER OXIMETERS DETERMINATION OF HB CONTENT 25 ml of capillary blood 15ml of Drabkin solution Change of all hemoglobin forms to methemoglobine and finally to cyanmethemoglobine in alkalic environment Wait Measure absorbance at 540 nm HEMATOCRITE - HCT Ratio of Erythrocytes to Whole blood!!! Whole blood erythrocytes HEMATOCRITE Men: 44 ± 5 % (0.44 ± 0.05) Women: 39 ± 4% (0.39 ± 0.04) Newborn: 55% Gravidity: lower Hct High altitude: higher Hct HEMATOCRITE anemia (lower number of red blood cells) trauma inner bleeding evaluation polycytemia (higher number of red blood cells) response to the treatment of anemia or polycytemia 1 blood transfusion = increase in hemotacrite by 3% dehydratation to or not to give transfusion decision if else healthy, transfusion is administered when hemoglobin is lower than 80g/l and hematocrite lower than 24% HEMATOCRITE Capillary blood to 2/3 of the capillary Free end of the glass capillary to be burned Centrifugation Read and explain the result TEICHMANN CRYSTALS Heating the dried blood in the presence of glacial acetic acid nad NaCl to form hematin. Capillary blood Make it dry Put NaCl and glacial acetic acid, heat Wait Observe under microsope Rhombic crystals, brownish color LEUKOCYTE COUNT As ERY count, only.... Different solution 50 squares Divide by 10 and multiply by 109, get No. of Leu in L of blood Normal values 3,5 – 9 x 109/L blood QUESTIONS?