Interpreting ABGs (or the ABCs of ABGs) Suneel Kumar MD.
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Transcript of Interpreting ABGs (or the ABCs of ABGs) Suneel Kumar MD.
![Page 1: Interpreting ABGs (or the ABCs of ABGs) Suneel Kumar MD.](https://reader030.fdocuments.us/reader030/viewer/2022032805/56649ef25503460f94c040e6/html5/thumbnails/1.jpg)
Interpreting ABGsInterpreting ABGs(or the ABCs of ABGs)(or the ABCs of ABGs)
Interpreting ABGsInterpreting ABGs(or the ABCs of ABGs)(or the ABCs of ABGs)
Suneel Kumar MDSuneel Kumar MD
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Arterial Blood Gases• Written in following manner:
pH/PaCO2/PaO2/HCO3
– pH = arterial blood pH
– PaCO2 = arterial pressure of CO2
– PaO2 = arterial pressure of O2
– HCO3 = serum bicarbonate concentration
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Oxygenation• Hypoxia: reduced oxygen
pressure in the alveolus (i.e. PAO2)
• Hypoxemia: reduced oxygen pressure in arterial blood (i.e. PaO2)
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Hypoxia with Low PaO2
• Alveolar diffusion impairment
• Decreased alveolar PO2
– Decreased FiO2
– Hypoventilation– High altitude
• R L shunt• V/Q mismatch
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Hypoxia with Normal PaO2
• Alterations in hemoglobin– Anemic hypoxia– Carbon monoxide poisoning– Methemoglobinemia
• Histotoxic hypoxia– Cyanide
• Hypoperfusion hypoxia or stagnant hypoxia
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Alveolar—Arterial Gradient
• Indirect measurement of V/Q abnormalities
• Normal A-a gradient is 10 mmHg• Rises with age• Rises by 5-7 mmHg for every 0.10
rise in FiO2, from loss of hypoxic vasoconstriction in the lungs
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Alveolar—Arterial Gradient
A-a gradient = PAO2 – PaO2
• PAO2 = alveolar PO2 (calculated)
• PaO2 = arterial PO2 (measured)
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Alveolar—Arterial Gradient
PAO2 = PIO2 – (PaCO2/RQ)
• PAO2 = alveolar PO2
• PIO2 = PO2 in inspired gas
• PaCO2 = arterial PCO2
• RQ = respiratory quotient
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Alveolar—Arterial Gradient
PIO2 = FiO2 (PB – PH2O)• PB = barometric pressure (760 mmHg)• PH2O = partial pressure of water vapor
(47 mmHg)
RQ = VCO2/VO2
• RQ defines the exchange of O2 and CO2 across the alveolar-capillary interface (0.8)
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Alveolar—Arterial Gradient
PAO2 = FiO2 (PB – PH2O) – (PaCO2/RQ)
Or
PAO2 = FiO2 (713) – (PaCO2/0.8)
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Alveolar—Arterial Gradient
• For room air:PAO2 = 150 – (PaCO2/0.8)
• And assume a normal PaCO2 (40):
PAO2 = 100
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Acid-Base
• Acidosis or alkalosis: any disorder that causes an alteration in pH
• Acidemia or alkalemia: alteration in blood pH; may be result of one or more disorders.
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Six Simple Steps1. Is there acidemia or alkalemia?2. Is the primary disturbance respiratory
or metabolic?3. Is the respiratory problem acute or
chronic?4. For metabolic, what is the anion gap?5. Are there any other processes in
anion gap acidosis?6. Is the respiratory compensation
adequate?
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Henderson-Hasselbach Equation
pH = pK + log [HCO3/PaCO2] x K(K = dissociation constant of CO2)
Or
[H+] = 24 x PaCO2/HCO3
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Henderson-Hasselbach Equation
pH7.207.307.407.507.60
[H+]6050403020
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Step 1:Acidemia or Alkalemia?
• Normal arterial pH is 7.40 ± 0.02– pH < 7.38 acidemia– pH > 7.42 alkalemia
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Step 2:Primary Disturbance
• Anything that alters HCO3 is a metabolic process
• Anything that alters PaCO2 is a respiratory process
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Step 2:Primary Disturbance
• If pH, there is either PaCO2 or HCO3
• If pH, there is either PaCO2 or HCO3
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Step 3:Respiratory
Acute/Chronic?• Acute:
CO2 by 10 pH by 0.08
• Chronic:CO2 by 10 pH by 0.03
• Changes in CO2 and pH are in opposite directions
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Step 4:For Metabolic, Anion Gap?
Anion gap = Na+ - (Cl- + HCO3-)
– Normal is < 12
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Increased Anion Gap• Ingestion of drugs or toxins
– Ethanol– Methanol– Ethylene glycol– Paraldehyde– Toluene– Ammonium chloride– Salicylates
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Increased Anion Gap• Ketoacidosis
– DKA– Alcoholic– Starvation
• Lactic acidosis• Renal failure
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Step 4:For Metabolic, Anion
Gap?
• If + AG, calculate Osm gap:
Calc Osm = (2 x Na+) + (glucose/18) + (BUN/2.8) + (EtOH/4.6)
Osm gap = measured Osm – calc Osm
Normal < 10 mOsm/kg
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Nongap Metabolic Acidosis
• Administration of acid or acid-producing substances– Hyperalimentation– Nonbicarbonate-containing IVF
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Nongap Metabolic Acidosis
• GI loss of HCO3
– Diarrhea– Pancreatic fistulas
• Renal loss of HCO3
– Distal (type I) RTA– Distal (type IV) RTA– Proximal (type II) RTA
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Nongap Metabolic Acidosis
• Calculate urine anion gap:Urine AG = (Na+ + K+) – Cl-
– Positive gap indicates renal impaired NH4
+ excretion
– Negative gap indicates normal NH4+
excretion and nonrenal cause
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Nongap Metabolic Acidosis
• Urine Cl- < 10 mEq/l is chloride responsive and accompanied by “contraction alkalosis” and is “saline responsive”
• Urine Cl- > 20 mEq/l is chloride resistant, and treatment is aimed at underlying disorder
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Step 5: Any other process with elevated
AG?• Calculate gap, or “gap-gap”:
Gap = Measured AG – Normal AG (12)
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Step 5: Any other process with elevated
AG?• Add gap to measured HCO3
– If normal (22-26), no other metabolic problems
– If < 22, then concomitant metabolic acidosis
– If > 26, then concomitant metabolic alkalosis
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Step 6: Adequate respiratory
compensation?Winter’s Formula
Expected PaCO2 = (1.5 x HCO3) + 8 ± 2
– If measured PaCO2 is higher, then concomitant respiratory acidosis
– If measured PaCO2 is lower, then concomitant respiratory alkalosis
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Step 6: Adequate respiratory
compensation?• In metabolic alkalosis, Winter’s
formula does not predict the respiratory response– PaCO2 will rise > 40 mmHg, but not
exceed 50-55 mmHg– For respiratory compensation, pH will
remain > 7.42
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Clues to a Mixed Disorder
• Normal pH with abnormal PaCO2 or HCO3
• PaCO2 and HCO3 move in opposite directions
• pH changes in opposite direction for a known primary disorder
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Case 1• A 24 year old student on the 6
year undergraduate plan is brought to the ER cyanotic and profoundly weak. His roommate has just returned from a semester in Africa. The patient had been observed admiring his roommate's authentic African blowgun and had scraped his finger on the tip of one of the poison darts (curare).
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Case 1
138 10026
7.08/80/37
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Case 1• What is the A-a gradient?
A-a gradient = [150 – 80/0.8] - 37A-a gradient = 13
• Acidemia or alkalemia?• Primary respiratory or metabolic?• Acute or chronic?
PCO2 by 40 would pH by 0.32
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Case 1• What is the anion gap?
AG = 138 – (100 + 26)AG = 12
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Case 1
• Acute respiratory acidosis
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Case 2• A 42 year old diabetic female who
has been on insulin since the age of 13 presents with a 4 day history of dysuria which has progressed to severe right flank pain. She has a temperature of 38.8ºC, a WBC of 14,000, and is disoriented.
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Case 2
135 99
124.8
7.23/25/113
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Case 2• What is the A-a gradient?
A-a = [150 – 25/0.8] – 113 = 6• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 135 – (99 + 12) = 24
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Case 2• What is the gap?
Gap = 24 – 12 = 12Gap + HCO3 = 12 + 12 = 24
– No other metabolic abnormalities
• Is the respiratory compensation appropriate?Expected PCO2 = (1.5 x 12) + 8 ± 2 =
24 ± 2– It is appropriate
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Case 2
• Acute anion gap metabolic acidosis (DKA)
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Case 3• A 71 year old male, retired
machinist, is admitted to the ICU with a history of increasing dyspnea, cough, and sputum production. He has a 120 pack-year smoking history, and quit 5 years previously. On exam he is moving minimal air despite using his accessory muscles of respiration. He has acral cyanosis.
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Case 3
135 93
30
7.21/75/41
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Case 3• What is the A-a gradient?
A-a = [150 – 75/.8] – 41 = 15• Acidemic or alkalemic?• Primary respiratory or metabolic?• Acute or chronic?
– Acute PCO2 by 35 would pH by 0.28
– Chronic PCO2 by 35 would pH by 0.105• Somewhere in between
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Case 3• What is the anion gap?
AG = 135 – (93 + 30) = 12
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Case 3
• Acute on chronic respiratory acidosis (COPD)
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Case 3b• This same patient is intubated and
mechanically ventilated. During the intubation he vomits and aspirates. He is ventilated with an FiO2 of 50%, tidal volumes of 850 mL, PEEP of 5, rate of 10. One hour later his ABG is 7.48/37/215.
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Case 3b• Why is he alkalotic with a normal
PCO2?– Chronic compensatory metabolic
alkalosis and acute respiratory alkalosis
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Case 4• A 23 year old female presents to
the Emergency Room complaining of chest tightness and light-headedness. Other symptoms include tingling and numbness in her fingertips and around her mouth. Her medications include Xanax and birth control pills, but she recently ran out of both.
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Case 4
135 10922
7.54/22/115
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Case 4• What is the A-a gradient?
A-a = [150 – 22/.8] – 115 = 8• Acidemia or alkalemia?• Primary respiratory or metabolic?• Acute or chronic?
– Acute CO2 by 18 would pH by 0.144
• What is the anion gap?AG = 135 – (109 + 22) = 4
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Case 4
• Acute respiratory alkalosis (panic attack)
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Case 5• 72 year old woman admitted from
a nursing home with one week history of diarrhea and fever.
133 1185
7.11/16/94
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Case 5• What is the A-a gradient?
A-a = [150 – 16/.8] – 94 = 36• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 133 – (118 + 5) = 10• Is respiratory compensation
adequate?PCO2 = (1.5 x 5) + 8 ± 2 = 16 ± 2
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Case 5
• Non anion gap metabolic acidosis (diarrhea)
• Compensatory respiratory alkalosis
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Case 6
• A 27 year old pregnant alcoholic with IDDM is admitted one week after stopping insulin and beginning a drinking binge. She has experienced severe nausea and vomiting for several days.
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Case 6
136 70
19
7.58/21/104
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Case 6• What is the A-a gradient?
A-a = [150 – 21/.8] – 104 = 20• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 136 – (70 + 19) = 47• What is the gap?
Gap = 47-12 = 35
Gap + HCO3 = 54
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Case 6
• Primary respiratory alkalosis (pregnancy)
• Anion gap metabolic acidosos (ketoacidosis)
• Nongap metabolic alkalosis (vomiting)
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Case 7• 35 year old male presents to the
ER unconscious.
145 70
23
7.61/24/78
Creat 6.1
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Case 7• What is the A-a gradient?
A-a = [150 – 24/.8] – 78 = 42• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 145 – (70 + 23) = 52
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Case 7
• What is the gap?
Gap = 52 - 12 = 40
Gap + HCO3 = 63–Nongap metabolic alkalosis
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Case 7
• Respiratory alkalosis• Anion gap metabolic acidosis
(renal failure)• Nongap metabolic alkalosis
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Bonus Case #1
• 51 year old man with polysubstance abuse, presented to ER with 3-4 day h/o N/V and diffuse abdominal pain. Reports no EtOH or cocaine in 2 weeks. He has been taking “a lot” of aspirin for pain. Denies dyspnea, but has been tachypneic since arrival.
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Bonus Case #1
• Afebrile, P 89, R 20, BP 142/57. Lethargic but arrousable, easily aggitated. Lungs clear, and abdomen is soft with mild tenderness in LUQ and LLQ.
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Bonus Case #1126
3.4
93
11
58
1.8218
UA 1+ ketones
Acetone negative
Lactate 6.9
EtOH 0
Osm 272
7.46/15/107
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Bonus Case #1• What is the A-a gradient?
A-a = [150 – 15/.8] – 107 = 25• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 126 – (93 + 11) = 22Anion gap metabolic acidosis
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Bonus Case #1• What is the gap?
Gap = 22 - 12 = 10
Gap + HCO3 = 21Nongap metabolic acidosis
• What is the osmolar gap?Calc Osm = 2x126 + 218/18 +
58/2.8Calc Osm = 265
Osm gap = 272 – 265 = 7
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Bonus Case #1
• Respiratory alkalosis (aspirin)• Anion gap metabolic acidosis
(aspirin)• Nongap metabolic acidosis
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Bonus Case # 2
• 20 year old college student brought to the ER by his fraternity brothers because they cannot wake him up. He had been in excellent health until the prior night.
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Bonus Case #2
• Afebrile, P 118, R 32, BP 120/70. Anicteric sclerae, pupils 8mm and poorly responsive to light. Fundoscopic exam with slight blurring of discs bilaterally and increased retinal sheen. Remainder of exam unremarkable.
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Bonus Case #2142
4.3
98
10
14 108
UA negative
EtOH 45
Osm 348 7.22/24/108
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Bonus Case #2• What is the A-a gradient?
A-a = [150 – 24/.8] – 108 = 12• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 142 – (98 + 10) = 34Anion gap metabolic acidosis
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Bonus Case #2• What is the gap?
Gap = 34 - 12 = 22
Gap + HCO3 = 32
Nongap metabolic alkalosis
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Bonus Case #2• What is the osmolar gap?
Calc Osm = 2x142 + 108/18 + 14/2.8 + 45/4.6
Calc Osm = 305Osm gap = 348 - 305 = 43
• Is the respiratory compensation adequate?
PCO2 = (1.5 x 10) + 8 ± 2 = 23 ± 2
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Bonus Case #2
• Anion gap metabolic acidosis with elevated osmolar gap (methanol)
• Nongap metabolic alkalosis• Compensatory respiratory
alkalosis
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Bonus Case #3
• A 23 year old man presents with confusion. He has had diabetes since age 12, and has been suffering from an intestinal flu for the last 24 hours. He has not been eating much, has vague stomach pain, stopped taking his insulin, and has been vomiting. His glucose is high.
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Bonus Case #3
130 80
10
7.20/25/68
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Bonus Case #3
• What is the A-a gradient?A-a = [150 – 25/.8] – 68 = 51
• Acidemia or alkalemia?• Primary respiratory or metabolic?• What is the anion gap?
AG = 130 – (80 + 10) = 40Anion gap metabolic acidosis
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Bonus Case #3
• What is the gap?
Gap = 40 - 12 = 28
Gap + HCO3 = 38
Nongap metabolic alkalosis
• Is the respiratory compensation adequate?
PCO2 = (1.5 x 10) + 8 ± 2 = 23 ± 2
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Bonus Case #3
• Anion gap metabolic acidosis (DKA)
• Metabolic metabolic alkalosis (emesis)
• Compensatory respiratory alkalosis
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Pulmonary Artery CathetersSuneel Kumar MD
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History
• In 1929, German surgical trainee Werner Forssman experimented on human cadavers
• Found that it was easy to guide a urologic catheter from arm veins into the right atrium
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History
• Forssmann went as far as to dissect the veins of his own forearm and guided a urologic catheter into his right atrium
• Used fluoroscopic control and a mirror
• Was able to walk to get a chest x-ray
• For his trouble, he was fired
• Eventually was awarded the Nobel Prize in 1956
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History
• Jeremy Swan and William Ganz from Cedars-Sinai developed a balloon-guided catheter placement
• Published in NEJM in August 1970• Idea came to Swan while watching sail
boats moving quickly on a calm day• Neither the physicians nor the
manufacturer were able to patent the balloon catheter
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Functional Cardiac Anatomy
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Uses of PA and Arterial Catheters• Allows assessment of both RV and LV
during diastolic and systolic phases
• Allows use of PCWP which is used to reflect the degree of pulmonary congestion
• Allows in assessment of blood flow (CO) and tissue oxygenation (SvO2)
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Use of PA Catheter
• To establish diagnosis
• To guide therapy
• To monitor response to therapy
• To assess determinants of tissue oxygenation
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Indications • Diagnosis of shock• Differentiate high vs
low pressure pulmonary edema
• Diagnosis of PPH • Assessment of
response to medications for PPH
• Diagnosis of valvular heart disease, intracardiac shunts, cardiac tamponade, and PE
• Monitoring and management of complicated AMI
• Assessing hemodynamic response to therapies
• Management of MOF and/or severe burns
• Management of hemodynamic instability after cardiac surgery
• Aspiration of air emboli
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Indications
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Contraindications
• Tricuspid or pulmonic valve mechanical protheses
• Right heart mass (thrombus or tumor)
• Tricuspid or pulmonic valve endocarditis
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Approaches to Access
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Approaches to Access
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Approaches to Access
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Approaches to Access
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Insertion Technique
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Proper Position
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Coiled PA Catheter
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Distal Cath Tip
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Lung Zones of West
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Lung Zones of West
PA > Pa > Pc
Pa > PA > Pc
Pa > Pc > PA
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Static Column of Blood to LA
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During Diastole:
• Tricuspid and mitral valves are open
• Blood leaves the atria and fill the ventricles
• Pressure between the atria and ventricles equalize
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At End-Diastole:
• Mean RA pressure equalizes with the RV end-diastolic pressure
• PA diastolic and PCWP equalize with the LV end-diastolic pressure
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Mean RA = RV EDP
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PA EDP and PCWP = LV EDP
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CVP/RA Waveform
• Three positive waves:– a wave (usually
largest)– c wave (may not be
seen)– v wave
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CVP/RA Waveform
• a wave is with atrial contraction• c wave is with closure of tricuspid valve• v wave is with blood filling atrium with tricuspid valve
is closed
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CVP/RA Waveform
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CVP/RA Waveform and EKG
• a wave in PR interval• c wave at end of QRS,
in RST junction• v wave after T wave
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Measuring Mean CVP
• Final filling of the ventricle occurs during atrial contraction (a wave)
• Therefore, average the a wave on the CVP/RA waveform
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Measuring the Mean CVP
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RV Waveform
• Sharp upstroke during systole, and downstroke during diastole
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RV Waveform
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RV Waveform
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RV to PA
• As the catheter goes past the pulmonic valve:– The systolic pressure is about the same
and now has a dicrotic notch (from closure of pulmonic valve)
– The diastolic pressure increases
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RV to PA
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PA Waveform
• PA systole within T wave• PA diastole at end of QRS
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PCWP Waveform
• Inflation of the balloon stops forward blood flow
• Creates a static column of blood between the catheter tip and the LA
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PCWP Waveform
• Has a waveform characteristic of the RA, primarily with a waves and v waves
• Mean PCWP is close to PA diastolic pressure
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PCWP Waveform and EKG
• a wave near end or after QRS
• v wave well after T wave
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Mean PCWP Measurement
• Final filling of the left ventricle occurs during atrial contraction
• Therefore, measure the average of the a wave
• Measure at the end of expiration
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Mean PCWP Measurement
12 + 6 / 2 = 9
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PCWP at End Expiration
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Waveform Review
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Calculating Cardiac Output
• Cardiac output done by thermodilution
• Known saline bolus (5-10 mL) at known temperature (usually < 25oC) injected via the proximal lumen
• Thermistor at end of SC catheter measures the change in temperature
• Change in temperature is inversely proportional to the CO
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Calculating Cardiac Output
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Calculating Cardiac Output
• Stewart-Hamilton formula:
CO = (vol of injectate) x (blood temp – injectate temp) x (computation constant) / (change in blood temp as a function of time, or AUC)
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Types of Shock
CO PCWP SVR
Cardiogenic
Hypovolemic /
Septic / Distributive N/
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Cardiogenic Shock
• Severely decreased cardiac output
• Extracardiac obstructive shock (e.g. cardiac tamponade) has equalization of pressures
• RAP = RV diastolic = PA diastolic = PCWP
• RA with minimal x and y descents, and elevation in mean RAP
• Loss of PA respiratory variations
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Constrictive Pericarditis
• Limited early diastolic filling
• Causes a plateau in the RV pressure
• “Square root sign”
• RAP has a “M” or “W” configuration
• a and v waves accentuated with rapid x and y descents
• Due to rheumatic disease, TB, metastatic carcinoma, prior chest XRT, or open heart surgery
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Constrictive Pericarditis
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Hypovolemic Shock
• Due to decreased blood volume
• Usually from hemorrhage or volume depletion
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Distributive / Septic Shock
• Due to peripheral vasodilation
• Other causes include anaplylaxis, neurogenic shock, Addisonian crisis, toxic shock syndrome, cirrhosis, and myxedema coma
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Information from PA Catheter
• Directly:– CVP– PA pressure– PCWP– CO
– SvO2
• Calculated:– Stoke volume/
index– Cardiac index– Systemic vascular
resistance (SVR)– Pulmonary vascular
resistance (PVR)– Oxygen delivery
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Formulas
• SVR = (MAP – CVP) / CO
• PVR = (MPAP – PCWP) / CO
• SV = CO / HR
• CaO2 = (1.39 x Hb x SaO2) + (0.003 x PaO2)
• DO2 = CaO2 x CO
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Normal Values
• SvO2• Stoke volume• Stroke index• Cardiac output• Cardiac index• MAP• CVP• PCWP• PA pressures• SVR• PVR
60-75%
50-100 mL/beat
25-45 mL/beat/m2
4-8 L/min
2.5-4.0 L/min/m2
70-110 mmHg
2-6 mmHg
8-12 mmHg
15-30 / 0-10 mmHg
900-1400 dynes.sec/cm5
40-150 dynes.sec/cm5
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Case # 1
• A 65 year old man with COPD required intubation for respiratory failure. He was placed on AC.
• Shortly after intubation, he developed hypotension and a SG catheter was placed, but a PCWP could not be obtained.
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Case # 1
• RA 4, sat 76%
• RV 45/0, sat 76%
• PA 45/20, mean 28, sat 77%
• PCWP ???
• BP 90/60, mean 70
• CO 5.7
• SVR 928
• 7.44 / 34 / 110, sat 99%
• Mixed venous 7.38 / 42 / 44, sat 77%
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Case # 2
• A 58 year old male is admitted to the CCU as a r/o MI.
• Developed respiratory distress.
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Case # 2
• RA 6, sat 65%
• RV 55/0, sat 66%
• PA 55/30, mean 45, sat 66%
• PCWP ???, sat 91%
• BP 110/80, mean 90
• CO 5.0
• SVR 1,344
• 7.44 / 35 / 80, sat 91%
• Mixed venous 7.40 / 40 / 36, sat 66%
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Case # 2
![Page 147: Interpreting ABGs (or the ABCs of ABGs) Suneel Kumar MD.](https://reader030.fdocuments.us/reader030/viewer/2022032805/56649ef25503460f94c040e6/html5/thumbnails/147.jpg)
Case # 3
• A 55 year old female is admitted with chest pain and shock.
• The EKG shows acute ischemic changes in the inferior limb leads.
• What is the diagnosis, and how would you treat her?
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Case # 3
• RA 14, sat 55%• RV 30/15, mean 20, sat 55%• PA 30/11, mean 20, sat 55%• PCWP • BP 90/60, mean 70• CO 2.5• SVR 1,792• 7.38 / 35 / 85, sat 90%• Mixed venous 7.34 / 41 / 32, sat 55%
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Case # 4
• A 50 year old male presents with syncope and shock.
• Room air ABG is obtained.
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Case # 4
• RA 15, sat 48%• RV 45/0, sat 48%• PA 45/20, mean 28, sat 49%• PCWP 7• BP 50/50, mean 60• CO 2.5• SVR 1,440• 7.32 / 32 / 59, sat 89%• Mixed venous 7.28 / 38 / 28, sat 49%
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Case # 5
• A 65 year old male with a two day history of weakness, dizziness, and dyspnea on exertion.
• On physical, noted to have a resting tachycardia.
• Chest x-ray shows a mediastinal mass.
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Case # 5
• RA 20, sat 71%• RV 45/19, sat 71%• PA 45/20, mean 28, sat 72%• PCWP 20, sat 96%• BP 90/70, mean 77• CO 4.0• SVR 1,140• 7.39 / 38 / 85, sat 96%• Mixed venous 7.38 / 40 / 40, sat 72%
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Case # 6
• A 112 year old male presents with tachypnea, confusion, and hypotension.
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Case # 6
• RA 2, sat 69%
• RV 42/0, sat 69%
• PA 45/15, mean 25, sat 70%
• PCWP 8, sat 85%
• BP 70/40, mean 50
• CO 6.5
• SVR 592
• 7.55 / 32 / 50, sat 85%
• Mixed venous 7.40 / 38 / 37, sat 70%
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Case # 7
• A 45 year old alcoholic with abdominal pain and hypotension.
• Chest x-ray shows a large, globular heart and a left pleural effusion.
• The Hct 45%.
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Case # 7
• RA 1, sat 49%
• RV 20/0, sat 49%
• PA 20/10, mean 13, sat 49%
• PCWP 4
• BP 80/50, mean 60
• CO 3.0
• SVR 1,576
• 7.34 / 30 / 80
• Mixed venous 7.31 / 38 / 28, sat 49%
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Case # 8
• 24 hours later, the prior patient in Case #7 becomes tachypneic.
• What complication has occurred?
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Case # 8
• RA 4, sat 64%• RV 45/0, sat 64%• PA 45/25, mean 32, sat 65%• PCWP 12• BP 110/70, mean 85• CO 6.1• SVR 1,064• 7.46 / 32 / 55, sat 89%• Mixed venous 7.40 / 31 / 35, sat 65%
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Case # 9
• A 98 year old male with confusion and hypotension.
• What kind of shock does he have?
![Page 160: Interpreting ABGs (or the ABCs of ABGs) Suneel Kumar MD.](https://reader030.fdocuments.us/reader030/viewer/2022032805/56649ef25503460f94c040e6/html5/thumbnails/160.jpg)
Case # 9
• RA 12, sat 47%• RV 40/12, sat 48%• PA 40/30, mean 33, sat 49%• PCWP 29, sat 90%• BP 80/50, mean 60• CO 2.5• SVR 1,536• 7.30 / 45 / 60, sat 90%• Mixed venous 7.26 / 50 / 28, sat 49%
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Case # 10
• 35 year old female with an abnormal chest x-ray and dyspnea on exertion.
• What is the diagnosis?
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Case # 10
• RA 8, sat 84%
• RV 60/0, sat 85%
• PA 45/20, mean 28, sat 86%
• PCWP 10, sat 99%
• BP 120/80, mean 95
• CO 9.4
• SVR 744
• 7.40 / 40 / 99, sat 99%
• Mixed venous 7.38 / 42 / 54, sat 86%
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Case # 11
• A 38 year old female presents with chest pain and dyspnea.
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Case # 11
• RA 8, sat 65%
• RV 110/10, sat 66%
• PA 90/50, mean 63, sat 67%
• PCWP 12, sat 98%
• BP 110/70, mean 83
• CO 3.2
• SVR 1,872
• 7.41 / 30 / 90, sat 98%
• Mixed venous 7.37 / 33 / 37, sat 67%
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Case # 12
• 18 year old female presents with exertional syncope.
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Case # 12
• RA 15, sat 78%
• RV 110/27, sat 90%
• PA 80/40, mean 60, sat 91%
• PCWP 28
• BP 120/80, mean 95, sat 99%
• CO 20
• SVR 800
• 7.40 / 40 / 99, sat 99%
• Mixed venous 7.38 / 42 / 79, sat 91%
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Suggested Websites
• www.pacep.org
• http://www.edwards.com/Products/PACatheters/CatheterizationTechniques.htm
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