TYPES OF HYPOXIA AND COMMON CAUSES

TYPES OF HYPOXIA AND COMMON CAUSES I. HYPOXEMIC (DECREASED TISSUE OXYGEN TENSION) A. HYPOXEMIC HYPOXIA (INADEQUATE ARTERIAL OXYGEN TENSION) CAUSES: A. V/Q MISMATCH (EX: COPD, PATIENT LAYING ON THEIR SIDE, PE) B. SHUNT (EX: ATELECTASIS, PULM. EDEMA) C. HYPOVENTILATION (EX: DRUG INDUCED) B. ANEMIC HYPOXIA (DEFICIENT OXYGEN-CARRYING CAPACITY OF THE BLOOD) CAUSES: A. ANEMIA (DECREASED HEMOGLOBIN) B. CARBON MONOXIDE POISONING C. SULFHEMOGLOBIN AND METHEMOGLOBIN ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care TYPES OF HYPOXIA AND COMMON CAUSES CONTINUED C. CIRCULATORY HYPOXIA (DECREASE PERIPHERAL CAPILLARY BLOOD FLOW) CAUSES: A. DECREASED CARDIAC OUTPUT B. VASCULAR INSUFFICIENCY (SEPSIS) D. HISTOTOXIC HYPOXIA (DECREASED UTILIZATION OF OXYGEN AT THE CELL LEVEL) CAUSES: A. CYANIDE POISONING B. ALCOHOL POISONING (RARE) ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care CONTENT VS TENSION (PaO2) A. CONTENT= TOTAL AMOUNT OF OXYGEN CARRIED IN BLOOD NORMAL = 20.7 VOL% CALCULATION: CaO2 = [%sat x l.39 x content] + [PaO2 x 0.003] EXAMPLES/NORMAL NORMAL Hb% = 15 GM%, 0.98 02 SAT = PaO2 = 100mmHg [1.39 X 0.98 x 15] + [100 x 0.003] = 20.7 vol.% ANEMIA Hb%, %sat = 98%, PaO2 = 100mmHg [1.39 x 0.98 x 10] + [100 x 0.003] = 14.2 vol.% HYPOXEMIA Hb% =15 gm%, %Sat=85%, PaO2=50mmHg »[1.39 x 0.85 x 15] = [50 x 0.003] = 18.0vol% NORMAL MIXED VENOUS CONTENT = 15% ARTERIAL VENOUS DIFFERENCE (A-V) = 5VOL% ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care CONTENT VS TENSION (PaO2) CONTINUED B. TENSION (PaO2) = AMOUNT OF OXYGEN DISSOLVED IN BLOOD NORMAL = 100mmHg [100 x 0.003] = 0.3% PaO2 = 1.5% OF THE TOTAL O2 CARRIED IN THE BLOOD ONLY Hg O2 CONTENT CARRIES 19.2 VOL% VS PaO2 CONTENT CARRYING 1.5 VOL% AS YOU CAN SEE PaO2 ISN'T ALWAYS THE MOST IMPORTANT OXYGENATION INDICATOR ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care ASSESSMENT: A. HYPOXIA , THE PATIENT PRESENTS WITH: A. AGITATION, PERSONALITY CHANGE B. HEADACHE, NAUSEA C. INCREASE IN PULSE D. INCREASE FREQUENCY OR SOB E. CYANOSIS: POOR SIGN, IF PRESENT IS MEANS SOMETHING. IF IT IS ABSENT IT DOES NOT MEAN MEAN ANYTHING ABOUT OXYGENATION STATUS. MAY BE A LOW Hct / Hb , SKIN COLOR, LIGHTING. B. HYPERCAPNEA PATIENT PRESENTS WITH: SOMNOLENT CAN NOT CONCENTRATE ASTERIXIS ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care A. X Y OXYGEN THERAPY G E THREE CLINICAL GOALS OF O2 THERAPY N 1. TREAT HYPOXEMIA 2. 3. DECREASE WORK OF BREATHING (WOB) DECREASE MYOCARDIAL WORK B. T H FACTORS THAT DETERMINE WHICH SYSTEM TO USE E 1. PATIENT COMFORT 2. THE LEVEL OF FIO2 THAT IS NEEDED R 3. THE REQUIREMENT THAT THE FIO2 BE CONTROLLED A BE CONTROLLED WITHIN A CERTAIN RANGE. P 4. THE LEVEL OF HUMIDIFICATION AND OR NEBULIZATION Y ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care HIGH FLOW VS LOW O2 SYSTEMS 1. HIGH FLOW SYSTEM DEFINED: THE GAS FLOW OF A DEVICE THAT IS ADEQUATE TO MEET ALL INSPIRATORY REQUIREMENTS. BY PROVIDING THE COMPLETE INSP. VOLUME, THE HIGH FLOW SYSTEM DELIVERS IT'S FIO2 VERY ACCURATELY. HIGH FLOW SYSTEMS CAN DELIVERY BOTH HIGH AND LOW CONCENTRATIONS OF O2. A. B. C. D. VENTURI MASK VENTURI TYPE NEBULIZERS (FAIL > .50 FIO2) HIGH FLOW BLENDER SYSTEM THE NEW GAS INJECTION NEBULIZER (GIN) WORKS FOR ALL FIO2S. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care HIGH FLOW VS LOW O2 SYSTEMS CONTINUED 2. LOW FLOW SYSTEM DEFINED: IS ONE THROUGH WHICH O2 IS DELIVERED TO SUPPLEMENT THE PATIENTS VT. THE FINAL FIO2 IS DETERMINED BY PROPORTIONATE MIXING OF THE NUMBER OF LITERS OF 100% OXYGEN BEING DELIVERED AND THE NUMBER OF THE PATIENT'S VOLUME OF ROOM AIR THE PATIENT BREATHS IN TO MIX WITH IT. FOR THE SAME OXYGEN FLOW THROUGH EITHER DEVICE, THE FINAL FIO2 WILL BE HIGHER IF THE VE IS LOW (HYPOVENTILATION) AND LOWER IF THE VE IS HIGH (HYPERVENTILATION). A. B. C. CANNULA SIMPLE MASK RESERVOIR OR NON-REBREATHER (HIGHEST FIO2) ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care COMPLICATIONS OF O2 THERAPY 1. RETROLENTAL FIBROPLASIA (RLF) DANGER IF PAO2 > 150 mmHg EFFECT: BLINDNESS DUE TO VASOCONSTRICTION AND ISCHHEMIA. (PREMATURE INFANTS ONLY) 2. OXYGEN TOXICITY ONSET PROPORTIONAL TO FIO2 & DURATION 100% > 24 HOURS. 50% FOR GREATER THAN 3 WEEKS. EFFECT: CONSOLIDATION (DECREASING PaO2S) & FIBROSIS. VICIOUS CIRCLE INCREASE FIO2 INCREASED DAMAGE/FIBROSIS, DECREASING PAO2 ETC. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care COMPLICATIONS OF O2 THERAPY Cont. 3. ABSORPTION ATELECTASIS 100% FIO2 BREATHING ASSOCIATED WITH DECREASED VENTILATION. (EX: OBSTRUCTION, MUCOUS PLUGGING, HYPOVENTILATION, ETC.) MAY OCCUR WITHIN 30 MIN. EFFECT: LUNG COLLAPSE WITH CONCOMITANT DECREASE IN PAO2. 4. DECREASED HYPOXIC DRIVE DECREASED VE DUE TO ALLEVIATION OF DRIVE OCCURS ONLY IN PATIENTS WHO ARE CHRONIC CO2 RETAINERS. EFFECT: HYPOVENTILATION WITH ACIDEMIA, IF UNCORRECTED CAN RESULT IN DEATH. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care O2 DELIVERY DEVICES Cont. EQUIPMENT NASAL CANNULA FLOW 1/2 - 6 L/M FIO2 .24 - 44*** SPECIAL NOTES 6 L/M MAX. *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care O2 DELIVERY DEVICES Cont. EQUIPMENT FLOW FIO2 SPECIAL NOTES SIMPLE O2 MASK (WITHOUT BAG) 6 - 10 L/M .35 - 55*** USE 5 L/M MINIMUM *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. O2 DELIVERY DEVICES Cont. EQUIPMENT FLOW FIO2 SPECIAL NOTES RESERVOIR MASK (MASK WITH BAG) 10-15 L/M .60 -80*** PAGE RT IF USED (BAG TO NOT COLLAPSE) *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care O2 DELIVERY DEVICES Cont. EQUIPMENT FLOW FIO2 SPECIAL NOTES VENTI MASK 3 L/M 6 L/M .24, 26, 31, .35, .40, .50 READ ENCLOSED INSTRUCTIONS *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care O2 DELIVERY DEVICES Cont. EQUIPMENT FLOW FIO2 SPECIAL NOTES NEBULIZER 8 L/M OR > .28, .30, .35 .40, .50, 70 1.0*** MIST MUST BE VISIBLE *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care O2 DELIVERY DEVICES Cont. EQUIPMENT FLOW FIO2 SPECIAL NOTES 12 -15 L/M 1.0 ANESTHESIA BAG *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. USE AT 12 L/M MIN. POTENTIAL OF BAROTRAUMA OR ASPHYXIATION ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care O2 DELIVERY DEVICES Cont. EQUIPMENT NASAL CANNULA SIMPLE O2 MASK (WITHOUT BAG) FLOW 1/2 - 6 L/M 6 - 10 L/M FIO2 .24 - 44*** .35 - 55*** SPECIAL NOTES 6 L/M MAX. USE 5 L/M MINIMUM RESERVOIR MASK (MASK WITH BAG) VENTI MASK 10-15 L/M 3 L/M 6 L/M .60 -80*** .24, 26, 31, .35, .40, .50 PAGE RT IF USED (BAG TO NOT COLLAPSE) READ ENCLOSED INSTRUCTIONS MIST MUST BE VISIBLE USE AT 12 L/M MIN. POTENTIAL OF BAROTRAUMA OR ASPHYXIATION ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care NEBULIZER 8 L/M OR > 12 -15 L/M ANESTHESIA BAG *** SHOWS THAT FIO2 VARIES WITH DIFFERENT F, VT, INSPIRATORY FLOW RATES. .28, .30, .35 .40, .50, 70 1.0*** 1.0 OXYGEN DISASSOCIATION CURVE SHIFT TO THE LEFT IN O2 CURVE 1. CAUSES: pH, CO2, 2-3 DPG, { O2 AFFINITY } TEMP. 2. RESULTS: O2 SAT. FOR AND PaO2 BUT RESULTING IN IN LESS GRADIENT TO MOVE O2 TO TISSUE. (CARRIES MORE O2 BUT MORE DIFFICULT TO RELEASE IT AT TISSUE LEVEL) 3. EXAMPLES: STORED BLOOD LOSES 2-3 DPG A SHIFT TO THE LEFT RESULTS FROM THIS. HYPERVENTILATION, HYPOTHERMIA. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care OXYGEN DISASSOCIATION CURVE CONTINUED SHIFT TO THE RIGHT IN O2 CURVE 1. CAUSES: pH, CO2, { O2 AFFINITY } TEMP. 2-3 DPG, 2. RESULTS: O2 SAT FOR ANY PaO2 BUT RESULTING IN MORE GRADIENT TO MOVE O2 INTO THE TISSUES. 3. EXAMPLES: HYPOVENTILATION, FEVER, METABOLIC ACIDOSIS. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care BOHR EFFECT BOHR EFFECT: AS BLOOD CIRCULATES FROM ARTERIAL TO VENOUS THE DISSOCIATION CURVE SHIFTS TO THE RIGHT (BECAUSE INCREASED CO2) WHICH FACILITATES DUMPING OF O2 AT THE TISSUE LEVEL. THIS DECREASES HEMOGLOBIN AFFINITY FOR O2. HALDANE EFFECT: WHEN HEMOGLOBIN CARRYING O2 (HbO2) LOSES ITS O2, IT WILL FACILITATE THE UPTAKE OF H+ ( HHb) WITH OUT ANY CHANGE IN pH. THUS HEMOGLOBIN ACTS AS A BUFFER. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care HALDANE EFFECT: BOHR EFFECT: AS BLOOD CIRCULATES FROM ARTERIAL TO VENOUS THE DISSOCIATION CURVE SHIFTS TO THE RIGHT (BECAUSE INCREASED CO2) WHICH FACILITATES DUMPING OF O2 AT THE TISSUE LEVEL. THIS DECREASES HEMOGLOBIN AFFINITY FOR O2. HALDANE EFFECT: WHEN HEMOGLOBIN CARRYING O2 (HbO2) LOSES ITS O2, IT WILL FACILITATE THE UPTAKE OF H+ ( HHb) WITH OUT ANY CHANGE IN pH. THUS HEMOGLOBIN ACTS AS A BUFFER. ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care HYPOXIA AND O2 DELIVERY DEVICES The End For more informatio n contact your local RCP By Terry Smith BS RRT ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care RCSW • • You can pass this program on for others use. You should transfer all files to the other person. If you choose to use it longer than the 30 day evaluation period (as shareware) please do one of the following in support of my writing it, and encouraging future topics to be written. – If you are not a member of the AARC please join and support your – – – – – – organization. We need all RCPs support. If you are a member, convince a RCP to join the AARC. If you do not regularly sign on the RCSW BBS system (at least once a week checking your mail at least) please start. Donate equipment or money to the RCSW BBS RCSW PO 242 Seahurst, WA 98062 – Use this program at your own risk. If you complete one of the above I will consider you a registered user. If you have not completed one of the four things after 30 days of use please delete this program. (or just do one). © TERRY’S TIPS FOR OXYGEN USAGE AND HYPOXIA copyrighted 1993 Terry Smith BS RRT ©Terry’s Tips On Oxygen Devices Terry Smith RRT Respiratory Care