Transcript Slide 1
Case Studies Medical Gas Therapy Case Study #1 Mr. Johnson arrives in the ER after a car accident. He is 25 years old and has no Hx of lung disease. His RR is 12 bpm and his Vt is approximately 1L/min. Mr. Johnson is on a nonrebreathing mask at approximately 70% FiO2. You obtain an ABG and the results are: pH 7.39 pCO2 34 HCO3- 20 PaO2 200 To obtain a PaO2 of 100 mmHg on Mr. Johnson, what FiO2 would you need to put him on?? Formula PaO2 (current) = PaO2 (desired) FiO2(current) new FiO2 (X) 200 mmHg = 100 mmHg .70 X SOLVE FOR X X = 35% What device do I put him on to achieve approximately 35% FiO2?? Cannula – what flow? 4 LPM Why?? 4 lpm X 4% = 16% 16% + RA (21%) = 37% What other device would work? Simple Mask – delivers 35% to 50% Partial Rebreather delivers 35% to 60% Air Entrainment Mask (venti mask) delivers 24% - 50% If I put Mr. Johnson on a venti mask, on the above FiO2 (35%), with a flow of 6 lpm, what would his total flow be?? Do the Magic Box to Obtain your Air:Oxygen Ratio 21 X 35 100 X Do the Magic Box to Obtain your Air:Oxygen Ratio 21 65 35 100 14 Air:Oxygen Ratio 65:14 AIR O2 Air:Oxygen Ratio (Simplify) 5:1 AIR O2 Add them together: 5+1 = 6 Multiply by lpm at the flowmeter: 6X6=36 TOTAL FLOW AT THE PATIENT’S AIRWAY IS: 36 LPM What is Mr. Johnson’s Ve? Formula: Ve = RR X Vt Formula: Ve = 12 X 1 (lpm) Formula: Ve = 12 lpm CASE STUDY #2 MRS. WADE Mrs. Wade is admitted to the ER with SOB. She has a Hx of smoking 4 packs of cigarettes a day for 40 years. She has been diagnosed with exacerbation of COPD. What is Mrs. Wade’s pack year HX? Pack Year HX Formula: # of packs/day X #of years smoked Mrs. Wade’s Pack Year HX: 4 X 40 = 160 pack years With Mrs. Wade being SOB and considering her Hx, what would you do to relieve her SOB? Put her on O2… What kind of O2 device would you use? Nasal Cannula (NC) at what flow?? Be safe with 2 lpm… What will happen to Mrs. Wade if you put her on 100% FiO2 ?? She will lose her Respiratory Drive What do you recommend now?? ABG?? Her ABG results are: pH 7.35 PCO2 80 HCO3 33 PaO2 55 Why is her PaO2 so low? What is the normal range for a patient who has COPD? 55-65 mmHg Mrs. Wade is still short of breath. She said she needs more air. What is a safe FiO2 range for her?? To obtain a PaO2 of 65 on her, what do I need to increase my FiO2 to?? She is currently on 2 lpm NC. What is her current FiO2?? 4% X 2 lpm =8% 8% + RA (21%)=29% She is on 29% FiO2 with a PaO2 of 55 mmHg. Formula PaO2 (current) = PaO2 (desired) FiO2(current) new FiO2 (X) 55 mmHg = 65 mmHg .29 X SOLVE FOR X X = 34% Since we don’t want to go over 34% FiO2, what device do we need to use? We would put her on a venti mask to supply her with more flow at an FiO2 of 30% and a 3lpm from the flowmeter. WHY?? What is her total flow?? Do the Magic Box to Obtain your Air:Oxygen Ratio 21 X 30 100 X Do the Magic Box to Obtain your Air:Oxygen Ratio 21 70 30 100 9 AIR:O2 RATIO IS: 70:9 OR 8:1 8+1=9 9 x 3 lpm = 18 Her total flow is 18 lpm Pictures of Oxygen Devices and Patients… THE END