Synergy with Critical Care Assessment: Cellular Homeostasis, Oxygenation and Technology - PowerPoint PPT Presentation

Loading...

PPT – Synergy with Critical Care Assessment: Cellular Homeostasis, Oxygenation and Technology PowerPoint presentation | free to view - id: 124a22-ZWEwZ



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Synergy with Critical Care Assessment: Cellular Homeostasis, Oxygenation and Technology

Description:

Discuss the role Oxygen Delivery plays in cellular homeostasis ... changes are transmitted to the pulmonary vasculature and affect blood flow. ... – PowerPoint PPT presentation

Number of Views:260
Avg rating:3.0/5.0
Slides: 66
Provided by: amu2
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Synergy with Critical Care Assessment: Cellular Homeostasis, Oxygenation and Technology


1
Synergy with Critical Care AssessmentCellular
Homeostasis, Oxygenation and Technology
2
Our Next Step
ASSESS OXYGEN DELIVERY!
3
Oxygen Delivery Objectives
  • Discuss the role Oxygen Delivery plays in
    cellular homeostasis
  • Identify discuss the main components of oxygen
    delivery and how we assess them
  • Identify various technologies on the market used
    to measure oxygen delivery
  • Case Study

4
Oxygen Delivery (DO2)
Johnsons conceptual model of oxygenation,
Wagner, Johnson Kidd (2006)
5
Failure of the Oxygen Delivery System SHOCK!
  • momentary pause in the act of death
  • John Collins Warren, 1800s
  • a rude unhinging of the machinery of life
  • Samuel Gross, 1872
  • pushing back the edge of death Mikhail, 1999

6
Optimal DO2 Aerobic Metabolism
7
Suboptimal DO2 Anaerobic Metabolism
8
Oxygen Delivery DO2
  • Which tissues are most effected by ? DO2?
  • Cardiomyocytes
  • Neurons
  • Kidney Liver (15-20 minutes)
  • Less effected
  • Skeletal muscle (60-90 minutes)
  • Hair Nails? (Leach Treacher, 2002)
  • Individual Organ DO2 measurement would be ideal
  • Optimizing DO2 EARLY Better Outcomes

9
Oxygen Delivery What are the components?
Oxygen Delivery DO2
Cardiac Output
CaO2
Stroke Volume
Heart Rate
PaO2
SaO2
Hgb
Preload
Afterload
Contractility
Synchrony
CVP PCWP
PVR SVR
EF
10
Oxygen Delivery SIMPLIFIED
  • Engine CO

Cargo Oxygen (4)
Cargo Cars Hemoglobin
Failure of any part of this train poor DO2.
What examples come to mind?
11
Oxygen Delivery DO2
  • DO2 is dependent on oxygen content (determines
    quality) in arterial blood (CaO2) CO
    (determines quantity)
  • FICK Formula for DO2 DO2 CO X CaO2 X 10
  • CaO2 (Hgb x 1.34 x SaO2) (PaO2 x .003)

Solubility coefficient for oxygen in plasma
ml of O2 that can be bound by 1 gm Hgb
12
Oxygen Delivery DO2
  • Simplified Formula
  • D02 CO X (Hgb X 1.34 X Sa02) X 10
  • (Notice that for practical purposes the PaO2 is
    removed?)
  • Normal 700 1400 ml/min.
  • How can we manipulate this? (Hint What are the
    three main components of the formula?)

13
Oxygen Delivery Lets break it down!
  • DO2
  • CO X CaO2 X 10
  • CaO2
  • Normal 20 mL O2/dL
  • PaO2
  • SaO2
  • Hgb
  • CO
  • HR
  • Preload
  • Afterload
  • Contractility

14
CaO2 ReviewPaO2
  • 2 of Oxygen dissolved in plasma
  • Reflects the tension (pressure) exerted by O2
    when dissolved in plasma
  • Little value in a PaO2 gt 90mmHg due to oxyhgb
    dissociation curve.
  • Did you know??? If PaO2 were
    our bodys only source of
    oxygen, we would need a C.O.
    of 120 l/minute to support life!

15
CaO2 ReviewPaO2
Law Bukira (1999)
16
CaO2 ReviewSO2
  • Measurement of the amount of oxygen bound to Hgb
    98
  • Hgb 4 iron-porphyrin groups (heme) attached to
    a protein (globin)
  • Each heme molecule can carry one O2 molecule ( 4
    per Hgb)
  • At rest, tissues only extract 25
  • SpO2 How does it work? Red infrared light,
    absorbed by hgb and transmitted through
    photodetector. Amount type of light
    transmittted through tissue is converted to a
    digital value.

17
CaO2 ReviewSpO2
  • Several Technical Limitations very dependent
    upon good blood flow (pressors?), sickle cell
    crisis, temp, light
  • Where is the best place for an SpO2?
  • Clinical Alert SpO2 overestimates SaO2 (Sequin,
    et al, 2000)
  • Once SaO2 falls lt80, accuracy for pulse ox ?s
  • Need SpO2 gt96 to ensure SaO2 gt90
  • Why is my ABG Sat different than my monitor sat??
  • Besides OxyHgb, SpO2 also measures
    Carboxyhemoglobin
    Methemoglobin
  • Masimo Radical 7 Co-oximeter

18
CaO2 ReviewHGB
  • Theoretically, increasing Hgb would increase DO2
  • Hgb gt 10 g/dL increased blood viscosity can
    impair blood flow
  • Increasing evidence of blood transfusions shows
    increased morbidity and mortality among open
    heart patients
  • Will a transfusion immediately improve DO2?
  • May take 18-24 hours to restore its 2,3 DPG An
    organic phosphate which alters affinity of Hgb
    for O2
  • 1 Unit PRBCs 500
  • Artificial Blood? (7.6 billion in U.S.) (Sarkar,
    S. 2008)

19
DO2 CO X CaO2 X 10Cardiac Output
  • The heart alone of all the viscera cannot
    withstand injury. This is to be expected because
    when the main source of strength is destroyed,
    there is no aid that can be brought to the other
    organs which depend on it. (Aristole 384BC
    322BC)

20
DO2 CO X CaO2 X 10
21
Oxygen Delivery
  • Cardiac Output Our 1st Responder!
  • Determined By
  • Preload (CVP PAWP)
  • Afterload (SVR PVR)
  • Contractility (EF)
  • Traditionally determined via PAC Thermodilution
    or CCO
  • New Technologies
  • Less Invasive
  • Non-Invasive

22
Cardiac Output/ Cardiac Index
  • Cardiac Output Amount of blood ejected from
    heart in 1 minute.
  • Normal 4-8L/Min
  • Cardiac Index Amount of blood ejected from heart
    in 1 minute/ BSA
  • Normal 2.5-4.5 L/Min

23
Continuous Cardiac Output
  • 10 cm Thermal filament lies b/t RA RV
  • Heats .02 degrees C and cools Sending signals to
    thermister at tip of PAC
  • Continuous Real Time
  • Value updated q 3-6 minutes/ time averaged

24
DO2CO Preload, Afterload, Contractility
  • Filling Pressures
  • AKA volume (indirectly)
  • Right Ventricular End Diastolic Volume
  • Left Ventricular End Diastolic Volume
  • Starlings Law of the heart
  • Effect of preload on CO.

25
Starlings Law The Heart is a Demand Pump
Preload determines the force and efficiency of
systolic ejection. Factors influencing preload
1. Total blood volume. 2. Distribution of blood
volume (venous tone). 3. Atrial Kick.
26
Preload Measurements
  • CVP
  • Normal 2-6 mm Hg
  • What is patients goal?
  • PAWP
  • Normal 6-12
  • Risks with wedging
  • PAWP/ PAD Relationship
  • PAD is generally to or within 4mm Hg higher
    than PAWP
  • PAWP can NEVER physiol. be gt PAD!!!
  • High Preload Causes
  • Fluid Overload
  • Heart failure
  • Myocardial infarction
  • Pericardial effusion or cardiac tamponade
  • Low Preload Causes
  • Absolute and Relative Hypovolemia
  • Treatments
  • Too Low?
  • Fluids
  • Blood if anemic
  • Treat cause of fluid loss
  • Too High?
  • Diuretics
  • Inotropes

What are we assuming here???
27
Preload Measurements Is there more than CVP
Wedge??
  • Pressure does not always volume
  • Ventricular compliance is dynamic
  • Volumetric parameters have been shown to reflect
    preload status more accurately (Cheatham, et al
    1998)
  • RVEF PAC can offer
  • SVO2
  • Stroke volume 60 100ml
  • End diastolic volume
  • Normal RVEDV 100-160ml
  • End systolic volume
  • Normal RVESV 50-100ml
  • RV ejection fraction
  • 40 - 60
  • Calculation of EF
  • EF SV
  • EDV

28
DO2CO Preload, Afterload, Contractility
  • Systemic vascular resistance
  • SVR
  • Resistance to ejection for left
    side of heart
  • MAP- CVP/CO 80
  • Normal 800-1200
  • Pulmonary vascular resistance
  • PVR
  • Resistance to ejection from right side of heart
  • Normal 50-250

29
DO2CO Preload, Afterload, Contractility
  • Defined as the ability to shorten and develop
    tension
  • A calculated value
  • Normal LVEF 60-70
  • Calculated values estimate the work of the heart
    (i.e., LVSWI, EF)
  • Echo, Nuclear Scan, RVEF PAC

30
Got Contractility???
31
Hemodynamic Monitoring Impedance for Accuracy
  • Transducer
  • HOB Elevation
  • PAC Zone Placement
  • Respiratory Variation
  • Waveform Interpretation
  • SCDS!

32
Hemodynamic Monitoring Transducer 1Priority
  • Does your transducer speak the same language as
    you? (translator)
  • Level / Zero at 4th ICS, MAL
  • For every inch the transducer is above/below the
    phlebostatic axis, the measurement is gt or lt2mmHg
    true value

33
Hemodynamic Monitoring Square Wave Test
  • How accurate is the system sensing pressure?
  • Fast Flush square wave test
  • Most frequent problem is empty flush bag or not
    pumped to 300mmHg

34
Hemodynamic Monitoring Patient Position
  • Measurements can be reliably measured with HOB _at_
    0 - 60 with patient supine (AACN 7 studies)
  • Measurements should be avoided in any side lying
    position
  • Allow 5 minutes b/t changes in position

35
Hemodynamic Monitoring Respiratory
Influences
  • Intrathoracic pressures changes are transmitted
    to the pulmonary vasculature and affect blood
    flow.
  • Spontaneous Breathing Decreases intrathoracic
    pressure. Take reading at top (Peak for patient)
    just before inspiratory dip.
  • Positive pressure ventilation Increases
    pressures. Take reading in valley of wave (Valley
    for vented) just before the upstroke.

36
Hemodynamic Monitoring Appropriate Catheter
Placement
37
Hemodynamic Monitoring Appropriate Catheter
Placement
38
Hemodynamic Monitoring Appropriate Catheter
Placement
  • Tip of catheter must be positioned below the
    level of the LA/ Lung Zone 3
  • In zone 3 arterial and venous pressures will
    exceed alveolar pressures accurate PAWP
  • Placement in zones 1 2 false high PAWP
  • Lateral CXR is best way to confirm ( but is this
    realistic???)
  • If PAWP gt PAD likely that catheter tip in zones 1
    or 2

39
Hemodynamic Monitoring Impedance for Accuracy
  • Killu, et al (2007)
  • 43 patients w/ PACs and SCDs
  • Findings CO measurements consistently lower
    while SCDs inflating
  • Theory cooler blood from lower limbs sent to PA
    during inflation of SCDs causes a lower temp
    reading therefore lower CO reading

40
Waveform Interpretation Review of Research
  • 1. Digital display from monitor (most common
    least accurate)
  • 2. Freeze framing respiratory pattern with wedge
    (cursor)
  • 3. Graphic strip recording of ECG CVP/ Wedge
    Most accurate
  • 3 Different Ways / One is most accurate!

41
Hemodynamic Monitoring Impedance for Accuracy
Studies evaluating physician and nursing
knowledge of HD waveform interpretations are
TROUBLING!
42
Hemodynamic Monitoring Impedance for Accuracy
  • AACN (1998)
  • These findings suggest that knowledge clinical
    competence in HD monitoring may be inadequate to
    ensure patient safety quality patient care
  • Zellinger (1995)
  • Found a 30 incidence of technical errors with
    PAWP readings. Errors were due to incorrect
    catheter transducer placement, incorrect
    zoning/ referencing, and pressure
    over/underdampening
  • AACN, SCCM, ACCP, ATS (1997)
  • Efforts must be taken to assure that this
    monitoring technology is being applied correctly
    and that effective QI programs r/t PAC are in
    place.

43
And the beat goes on..
  • Last several years of research and technology has
    been focused on the invention of less
    non-invasive hemodynamic monitoring capabilities.

44
DO2 Technologies
  • RVEF PAC Continuous end-diastolic volume
  • measures RVED volumes and offers an improved
    assessment of preload recruitable CO
  • provides continuous EF, SV, SVO2 (EF drops
    before any other clinical s/s)
  • Technology Uses ECG in correlation w/
    beat-to-beat changes in temperature that occur
    b/t contractions of the heart.
  • Limitations Uses with heart failure patients?
    (RVEF vs LVEF), Inaccurate with ectopy and high
    HR

45
DO2 Technologies
  • Esophageal Doppler Cardiac Output Monitoring
  • NG tube type probe inserted into esophagus 40cm
    aligned to measure aortic blood flow
  • Measures SV and HR adjusted CO, Flow Time and
    Peak Velocity
  • Simple less invasive
  • Usually requires patient sedation
  • Cannot be used with esophageal varices

46
Esophageal Doppler Cardiac Output Monitoring
47
DO2 Technologies
  • Capnography CO2 Measurement of Cardiac Output
  • Completely non-invasive
  • Rebreathing circuit attached to vent
  • Assesses the change in exhaled CO2 during
    rebreathing and normal breathing (PetCO2)
  • Uses modified Fick Equation
  • Concept The amount of a substance taken up or
    produced by an organ is the product of the flow
    of blood through the organ
  • Limitations need a controlled ventilated patient
    (OR), Only measures blood flow that participates
    in gas exchange (QS/QT)

48
Capnography CO2 Measurement of Cardiac Output
49
DO2 Technologies
  • Gastric Tonometry
  • Principle Gut is referred to as canary of the
    body. Responds to subtle perfusion deficits.
  • Modified NG tube w/ gas permeable balloon at end
  • CO2 diffuses from mucosal layer of stomach into
    balloon
  • Gives values every 10 minutes
  • Value gt45 hypoperfusion in tissue beds
  • Limitations Tube feeds

50
DO2 Technologies
  • Bioimpedance Cardiography
  • Non-invasive, Electrodes placed on jugulars,
    chest
  • Uses a low-amplitude, high frequency alternating
    signal to calculate impedance of the flow of
    electricity through the chest.
  • Derives parameters CO, CI, SV, SVR (calculated
    with pts MAP CVP)
  • Limitations Pts must be very still, no ectopy,
    strong signals

51
BioZ ICG Monitor
52
DO2 Technologies
  • Arterial Pressure-Based CO (APCO)
  • Attaches to A-Line
  • Takes age, sex, BSA into account
  • Assesses pulse pressure (SBP DBP) variations to
    determine SV
  • HR X SV CO
  • Stroke Volume Variation (pulses paradoxus) gt
    10-15 fluid responsive pt
  • Limitations Majority studies done on controlled
    MV patients, but newer data is out.

53
DO2 Technologies Doppler
  • Ultrasound device
  • Measures blood flow across Aortic
    and Mitral Valves
  • Beat-to-beat CO and SV measurements
  • Simple to use/ portable
  • Data available 2 - 6 minutes
  • Need gt 100 patients to be proficient

54
USCOM Doppler
55
DO2 TechnologiesNICOM Noninvasive CO Monitor
  • Uses chest Bioimpedance Bioreactance
    technology (an analysis of frequency related
    effects greater noise elimination)
  • Measurements include CO, CI, SV, SVV, SVI,
    Thoracic Fluid Content, NIBP
  • Advantages Studied on pts at rest as well as
    exercising

56
Oxygen Delivery What if you dont have fancy
equipment?? Can be challenging.
  • LOC
  • Skin color
  • Peripheral Edema (lbs?)
  • Capillary refill (children maybe, elderly - no)
  • Heart Rate BP (Late)
  • Skin Temperature (Late)
  • Urine Output (Late)
  • Ultimately we must monitor oxygenation end points
    to determine if our delivery is sufficient!

57
Time for a DO2 Case Study
58
80 y/o male admitted to the ICU post-op CABG to
LAD, Circumflex and RCA. Currently the patient is
receiving sodium nitroprusside and nitroglycerin.
59
250cc Albumin was administered to increase urine
output
60
250cc Albumin was repeated
61
Frank-Starling Curve for this patient with SV
EDV Data
EF 30 10pm
Stroke Volume
EF 24 9pm
EF31 8pm
EF 38 7pm
EDV
62
Dobutamine 6 mcg/kg/min was started
63
DO2 Questions to ask yourself
  • Is the DO2 meeting the patient needs at this time
    (global as well as regional)?
  • Is the DO2 occurring with adequate perfusion
    pressure?
  • Is the patient able to use the oxygen being
    delivered?
  • If you answer no, then what interventions are
    needed?

64
Nursing Survivor???
65
Even with an optimal DO2, your patient can still
be in trouble.
We can lead a horseto water, but
After lunch Oxygen Consumption
About PowerShow.com