School of Medicine SUNYAB PGY452 Respiratory Lectures March 26 2015 Daniel D Swartz Ph D Lecture 6 Blood Gas Transport Reading Assignment Berne Levy chapter 23 pages 459 467 Transport of O2 and CO2 in the Blood 20 3vol Erythropoietin EPO increase RBC Hb oxygen content Post surgical patients Blood doping train at altitude will increase EPO however increase viscocity increase resistance Figure 18 6 70 of iron found in the body is located in the heme of red blood cells Each heme can bind one oxygen molecule Fetal hemoglobi n consist of two alpha chains and two gamma chains Figure 18 8a Pvco2 46 pH 7 38 Temp 38 Reversible reaction in the lung carboxyhemoglo bin buffer Carbonic acid 7 23 70 Buffer Paco2 40 pH 7 40 Temp 37 OXYGEN CONTENT mlO2 100ml blood Oxygen Dissociation Curve 98 bound to Hb 2 dissolved Venous Arterial OXYGEN CONTENT mlO2 100ml blood 98 O2 2 First oxygen 60 mmHg Second oxygen 10 mmHg Exercise Third oxygen 10mmHg OXYGEN SATURATION Anemia same as normal just less Hb CO poisoning treat with hyperbaric chamber Hyperbaric chamber bends nitrogen accumulation Anaerobic infections gangrene Fig 23 6 B L CO binds 200X stronger than oxygen EFFECT OF CARBON MONOXIDE CO AND ANEMIA ON OXYGEN CONTENT CO poisoning oxygen dissociates more difficult Anemia many causes of anemia Fig 23 7 B L Oxygen consumption at rest 250ml O2 min Exercise cardiac output 25 L min 5X venous oxygen content 3X Oxygen consumption is then 15X normal Oxygen consumption at exercise 4L O2 min Spleen stores RBCs to release when needed in other animals seals Arterial blood can not be change from 20 vol Remove 3 oxygen Hb 3X increase 15 5 vol Conformational change releases oxygen more easily pCO2 40 ph 7 40 t 37 arterial blood pCO2 46 ph 7 37 t 38 venous blood Cv02 ph Fig 23 5 B L Linear curve for CO2 52 vol 48 vol venous R Respiratory Quotient or Respiratory Exchange Ratio It is the amount of CO2 produced divided by the amount of O2 consumed It is dependent on caloric intake and ranges between 0 7 only fatty acids metabolized and 1 only carbohydrates metabolized R 0 8 for only protein metabolism For a normal diet in a person at rest R 0 8 with 200ml of CO 2 being produced each minute and 250 ml of O2 being consumed 200 ml CO2 250 ml O2 0 8 R Chap 22 pg 445 Alveolar Gas Equation R Respiratory Quotient or Respiratory Exchange Ratio It is the amount of CO2 produced divided by the amount of O2 consumed It is dependent on caloric intake and ranges between 0 7 only fatty acids metabolized and 1 only carbohydrates metabolized R 0 8 for only protein metabolism For a normal diet in a person at rest R 0 8 with 200ml of CO2 being produced each minute and 250 ml of O2 being consumed 200 ml CO2 250 ml O2 0 8 R
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