basic overview of hemodynamics
TRANSCRIPT
-
8/12/2019 Basic Overview of Hemodynamics
1/38
Hemodynamics and Shock
NUCO 4220
Spring 2014
1
-
8/12/2019 Basic Overview of Hemodynamics
2/38
Tissue and Organ Perfusion Influenced by
Amount of O2 in arteries that reaches cell(how much pumped from heart reaches
cells)
2
Factors that Influence MAP
- Heart- Size of vascular bed
- Volume of blood w/in vessels
-
8/12/2019 Basic Overview of Hemodynamics
3/38
MAP (Mean Arterial Pressure)
Mean arterial pressure
SVR x CO (+CVP: often negligible)
OR [(2Xdiastolic) + systolic] / 3 (never calculate)
Norm: 70-110 mmHg
- avg BP (more direct measure than cuff)
- Arterial pressure when heart pumping
- An indicator of perfusion
- MAP > 60 to perfuse kidneys, brain and
coronary arteries (gut takes hit early)
- MAP 101 = good perfusion3
-
8/12/2019 Basic Overview of Hemodynamics
4/38
Arterial Line
2 uses: get blood, getMAP
Change tube q96h
Sterile dressings last
about a wk
*Dont memorize waveform*
jeffreymlevinemd.com 4
-
8/12/2019 Basic Overview of Hemodynamics
5/38
Arterial Line Set Up
aic.cuhk.edu.hk 5
500ml Norm Saline
(not always w/
heparin, risk for HIT)
Pressure Bag to
force fluid against
artery (which pushes
stuff out)
All sit in transducer
holder, leveled at
right atrium
-
8/12/2019 Basic Overview of Hemodynamics
6/38
Transducer placement
6
Plastic holder often onHOB bc always has to be
zeroed to give accurate
read
0 it every shift so dont getatmospheric pressure
Phlebostatic Axis:
4thintercostal space and
mid-axillary (btw interior-
posterior diameter) @
right atrium
-
8/12/2019 Basic Overview of Hemodynamics
7/38
CVP or RA Pressure
MAP = central core BP
CVP/RA = central venouspressure (comes from RA)
Long line inserted subclavian
(jugular/femoral risk infxn)
Tip in RAgives sense of fluid
thats been returned to heart
from body
Ex: low UO, so measure howmuch of bolus circulating well
How much blood to pulmonary
arteries to get oxygenated
Norm: 2-8 7
-
8/12/2019 Basic Overview of Hemodynamics
8/38
CVP
Norm 2-8 mm Hg
Guidelines:
8-12 to avoid hypovolemia
(ex: burn)
>12 if pt on mechanical vent
PEEP volutrauma can
compress capillaries and decr
vol to heart (and CO)
giveextra vol so vessels less likely
to collapse
Level to RA and 0 every shift
8
-
8/12/2019 Basic Overview of Hemodynamics
9/38
Swan Ganz Catheter
nlm.nih.gov 9
RA to RV up into pulm vasculature Risk perforate lung, valve, artery, infxn,
dysrhythmias (block), etc.
-
8/12/2019 Basic Overview of Hemodynamics
10/38
Swan Ganz Catheter
10
Most have 6 ports
Can deliver inotrope
into heart immediately
Can get CVP Only way to continuouslymonitor pulm artery
pressure
-
8/12/2019 Basic Overview of Hemodynamics
11/38
Swan-Ganz Measurements (mmHg)
R Atrium (CVP) Right Ventricle
Systolic 15-30
Diastolic 3-8 Pulmonary Artery
How constricted or dilated is pulm pressure
Pulmonary Wedge (L. Atrium)Indirect 2-15
Wedge off pressure for a moment and get
reflective value of LA (based on build-up in RA?)11
-
8/12/2019 Basic Overview of Hemodynamics
12/38
Pulmonary Artery Pressure
Systolic 15-25
Diastolic 8-15
Mean 10-20
Pulm HTN = PAP > 25
Is pulm system vasoconstricted?
Ex: improve CO by giving fluid, but if still low, getPAP:
High PAP (constricted), fluid cant get throughresistance w/ same vol & speed to produce CO on otherside (tx: vasodilate)
CVP can look good but still low perfusion, giving lots offluids risks pushing into RHF
Also obtained from cardiac cath
12
-
8/12/2019 Basic Overview of Hemodynamics
13/38
Pulmonary Artery Pressure
Heart Failure
Sepsis
Clot Low flow not necessarily r/t constriction
Clot in pulm vasculature would cause low flow
Effectiveness of Tx/ Meds
13
-
8/12/2019 Basic Overview of Hemodynamics
14/38
Mixed Venous Oxygen
% of reduced hgb left after tissue oxygen extraction
How much O2 left on hgb after it blood has circulated
Blood gets O2 in pulm vasculature, pumps to body,
and has lowest O2 right before entering again
SvO2 Normvalue 60 - 80%.
< 60 if cells/organs need more
Ex: in marathon, cells need more O2, so pull free O2 frombody, and wont see immediate drop in SaO2 and SvO2??
but septic pt wont have that O2 reserve and see quick
drop in SaO2
14
-
8/12/2019 Basic Overview of Hemodynamics
15/38
Oxygen Delivery
Hgb
O2 saturation
CO
http://www.bing.com/images/search?q=oxygen+delivery+cells&FORM=BIFD#focal=88d8a54e16da437f9dc6864efb8e19f2&furl=http%3A%2F%2Fwww.oneminutecure.com%2FDissociationHemoglobinOxygen.jpg 15
http://www.bing.com/images/search?q=oxygen+delivery+cells&FORM=BIFDhttp://www.bing.com/images/search?q=oxygen+delivery+cells&FORM=BIFDhttp://www.bing.com/images/search?q=oxygen+delivery+cells&FORM=BIFDhttp://www.bing.com/images/search?q=oxygen+delivery+cells&FORM=BIFD -
8/12/2019 Basic Overview of Hemodynamics
16/38
CO = Heart Rate x Stroke Volume
Heart Rate Stroke Volume (SV)
Fluid from LV left over after
final LV contraction
Amount of vol of blood being
pumped to tissues
Norm CO = 4-8L/min
End-Diastolic Vol minusEnd-Systolic Vol
16
-
8/12/2019 Basic Overview of Hemodynamics
17/38
Stroke Volume
Measurement of Volusing Echocardiogram How much making it out to tissues
Gives info of how circulating, how well its squeezingon inotrope (can actually see contraction/squeeze),see color-coded arterial & venous flow
Used to assess vol response to fluids and meds
Esophageal Doppler***** Probe into esophagus near heart gives good output
Non-invasive Doppler: THE FUTURE
17
-
8/12/2019 Basic Overview of Hemodynamics
18/38
Shock- Side-effect (syndrome/condition) r/t how much vol
circulating to perfuse organs
- Decr blood vol w/o constricted capillary bed can lead toshock- Ex: hemorrhage (losing vol), so if capillary bed doesnt constrict
and MAP doesnt incr, organs will die quickly
- Capillary beds dilate excessively, go into shock bc not enoughtension/resistance to perfuse organs
- Compensate early one (ie capillaries constrict when vol decr),but if doesnt, go into shock fast
It is a widespread abnormal cellular metabolism that occurswhen the human need for oxygenation and tissue perfusion
is not met to the level needed to maintain cell function.All body organs are affected and either work harder to
compensate or fail due to hypoxia
Iggy, Chapter 39, pp 826
-
8/12/2019 Basic Overview of Hemodynamics
19/38
Blood Volume, Capillary Bed & MAP
19
-
8/12/2019 Basic Overview of Hemodynamics
20/38
Hypoperfusion
Cellular hypoxia (w/ build-up of lactic acid) Cell death r/t hypoxia cause incr lactic
Aerobic (with O2) metabolismanaerobic
(without O2) metabolism
lactate and H+ions
lactic acidosis (metabolic)
20
-
8/12/2019 Basic Overview of Hemodynamics
21/38
Lactate
0.51 mmol/L: Normal
2 mmol/L: Slight elevation
25 mmol/L: Mild-moderate
> 5 mmol/L: Lactic acidosis (with low pH)
**Concern when above 2
Get ABG w/ lactatetells to what degreebody didnt or no longer able tocompensating
Lactic acid means no compensationneed to
intervene 21
-
8/12/2019 Basic Overview of Hemodynamics
22/38
Hypoxia Tolerance
22
Heart, Brain, Kidney canttoleratehypoxemia
Skin, Skeletal Muscles can tolerate
hypoxia for awhile
Liver = middle rode tolerance
-
8/12/2019 Basic Overview of Hemodynamics
23/38
4 Types of Shock
Hypovolemic (low vol) Give fluids
Cardiogenic
Ex: MI impairs CO
Distributive (anything that affects periph vasc) Septic
Anaphylactic Neurogenic
Obstructive (rare)23
-
8/12/2019 Basic Overview of Hemodynamics
24/38
Stages of shock (Iggy, Table 39-3) Early (preshock)
MAP decr by 5-10 HR up a little to incr CO and compensate
Some vasoconstriction
Compensatory (**identify & intervene**)
MAP decr 10-15 HR up (whats pt baseline), decr UO
Ned to reverse quickly before tissue death
Progressive Compensatory mechanisms fail
MAP decr 20-40 , severe hypoxemia, poor CO & UO
Refractory Almost impossible to reverse
MODS24
H l i Sh k
-
8/12/2019 Basic Overview of Hemodynamics
25/38
Hypovolemic Shock
Fluid Depletion
25
Extreme dehydration: Dehydration = vol loss (expect incr CO (w/ incr HR & BP)
and capillary constriction
When cant compensate, MAP decr
Blood loss:
Losing O2 carrying capacity
Cant compensate long
Tx:
Pressure bag fluids
Central line (access and CVP read)
If hemorrhage: start fluids before blood arrives (even if not
type & screen yet)
C di i Sh k
-
8/12/2019 Basic Overview of Hemodynamics
26/38
Cardiogenic Shock
Direct Pump Failure
26
So much cardiac damage that pump doesnt work
Low CO, so capillaries need to vasoconstrictor to
maintain circulating vol
Dont give extra vol bc dont have mechanism tohelp w/ CO
Dont give inotrope, bc it make heart squeeze too
much and further cardiac cell death
Tx: cath lab and/or LVAD type pumps until
transplant (if needed)
IABC: Intra aortic counterpulsation
-
8/12/2019 Basic Overview of Hemodynamics
27/38
IABC: Intra-aortic counterpulsation
(Intraaortic balloon pumpIABP)
Cardiac cycle
Increase coronary
perfusion
Decrease afterload
27
http://library.med.utah.edu/kw/pharm/hyper_heart1.htmlhttp://library.med.utah.edu/kw/pharm/hyper_heart1.html -
8/12/2019 Basic Overview of Hemodynamics
28/38
Distributive Shock:
Massive Vasodilation
28
Leaking vessels
Spinal cord injury:
Nerve innervation
affects constriction,cant hold tone
Losing fluid to tissues
-
8/12/2019 Basic Overview of Hemodynamics
29/38
Distributive Shock
Septic Anaphylactic
Epi-pen is vasoconstrictor
Neurogenic
Too many opioids or drugs affecting tone(?)
Tx:
Lots of vasodilation: incr vol (to fill space) orincr CO (to incr pressure)
Potentially get inotrope
Correct underlying condition
29
Sepsis Bundles:
-
8/12/2019 Basic Overview of Hemodynamics
30/38
Sepsis Bundles:Surviving Sepsis Campaign (2008)
Element 1: Measure serum lactate (act if >2)
Element 2: Get blood cultures prior to giving broad-spectrum
antibx
Element 3: Administer antibx w/in 3hrs of ED & 1hr of Non-EDadmit
Element 4: Tx hypotension and lactate w/ fluids. Maintain MAP>
65. Use vasopressors for ongoing hypotension.
- Give liters of fluids, once MAP >65, stop boluses, but continuefluids
Element 5: Maintain CVP > 8mmHg and Mixed Venous O2 > 65%
30
-
8/12/2019 Basic Overview of Hemodynamics
31/38
Sepsis Management BundleEvidence-based goal is to perform all indicated tasks 100% of time w/in first
24 hrs of presentation
1. Administer low dose steroids
r/t inflammatory mediators
2. Maintain glucose control lower limit of norm but
-
8/12/2019 Basic Overview of Hemodynamics
32/38
Assessment CV status1stsign of
shock As MAP drops, pulse
pressure low (lesspalpable)
Renal Decr UO
Respiratory
Incr RR
Metab acidosis so respkicks in to compensate(blow off CO2)
Integumentary
Cool skin, diaphoresis,slow cap refill, 32
Musculoskeletal Tolerates hypoxia well, so
see late changes Decr movement and
strength
CNSalso an early sign
Something off Incr neuron firing: twitch,agitated, anxious
Lab valuesH/H, Lacticacid, K+
Get ABGs after other tasks Adjust K+ quickly (if
hyperkalemia, glucose orCa+ (?) to send K+intracellularly, can give
kaexolate later)
-
8/12/2019 Basic Overview of Hemodynamics
33/38
Management
Oxygen therapyneed O2
IV therapyCrystalloids, Colloids, Blood
Hemodynamic monitoringMAP,CVP, (SV) Drug therapyVasoconstrictors, Inotropes,
Myocardial perfusion agents
Treat underlying condition If anaphylaxis, give epi; if MI, etc.
33
-
8/12/2019 Basic Overview of Hemodynamics
34/38
PracticeWhich client should the nurse evaluate for
neural-induced distributive shock? A. The 25-year-old receiving 500 mg of
penicillin IV.
B. The 47-year-old with sudden-onsetsevere chest pain and dyspnea.
C. The 21-year-old who has received 4
mg of morphine IV for acute pain. D. The 82-year-old who has had severevomiting and diarrhea for 2 days.
34
-
8/12/2019 Basic Overview of Hemodynamics
35/38
35
Case Study
A 53-yr old man is s/p open reduction of right
forearm after falling from a tree while trimmingit. PMH: mild hypertension, 15 # underweight.PSH: smokes two packs of cigarettes anddrinks a six-pack of beer daily. VS : BP,142/90; HR 86; RR 18; O2 Sat 97%. Exam:forearm dressing is dry & intact, fingers arewarm & pink with good cap refill. He responds
to his name, but does not open his eyes.1. Are any indications of shock currently
present?
It is now 15 minutes later BP 140/92; HR 92;
-
8/12/2019 Basic Overview of Hemodynamics
36/38
36
It is now 15 minutes later, BP 140/92; HR 92;
RR 18, O2 Sat 95%. Dressing is dry & intact,
fingers are slightly cool, and cap refill is slightly
slower than baseline assessment. He is awakeand tells you that his right arm hurts and that
he is thirsty. You administer the prescribed
analgesic by injection.
2. Are any indications of shock currently
present? .3. What should you check regarding the
coolness of the fingers?
4. Should you give him sips of water?
15 minutes later VS are BP 132/96; HR 100;
-
8/12/2019 Basic Overview of Hemodynamics
37/38
37
15 minutes later, VS are BP 132/96; HR 100;RR 22. Pain is better but he is very thirsty,light-headed & mildly nauseous. He reports
belcheing. Postop orders state: Remove IVafter 1000 mL has infused, if stable
5. Are any of the changes in VS a cause forconcern?
6. Could the changes in VS be related to eitherhis pain or the analgesic?
7. Where should you look for postop bleeding?
8. Should you remove his IV at this time?
9. Should retake VS in 15 minutes?
-
8/12/2019 Basic Overview of Hemodynamics
38/38
38
10 minutes later: BP, 106/80; HR 112; RR 26,
O2 Sat 90%. You start to check his cap refill,
he says Josey (his wifes name), bring me abucket, I feel sick. He vomits a large amount
of bright red blood.
10. What vital sign changes are consistent with
shock?
11. What stage of shock is present?
12. What is the most likely cause of thebleeding?
13. Is there anything the nurse could have
d diff tl t id tif h k li ?