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Principles of Surgery - PGY 1 and PGY 2
SHOCK – EVIDENCE BASED
Sandro Rizoli, MD, FRCSC, PhD, FACS
Associate Professor Surgery and Critical Care Medicine
De Souza Trauma Research Chair
CIHR New Investigator
GOAL
1. Preparation for the exams
2. Theoretical basis for practice
MASTER PLAN
1.
2.
3.
4.
5.
Definition
Classification
History
Pathophysiology
Hypovolemic Shock
• Therapy
• Novel ideas
6. Septic shock
• Definition
• Current guidelines
QUESTION #1
With regards to the distribution and composition of the body
fluid compartments, which of the following statements is/are correct?
a) Most intracellular water is in skeletal muscle.
b) The major intracellular cation is sodium.
c) The major intracellular anions are proteins and phosphates.
d) The major extracellular cation is sodium.
DEFINITION
• Inadequate tissue perfusion
• Imbalance between substrate supply (DO2)
and demand (VO2) at a cellular level
• Dysfunction of cellular biochemistry
cell membrane pump dysfunction
intracellular edema
leak intracellular contents
inadequate regulation intracellular pH
DEFINITION
• Initially reversible
• Cell death – organ damage – failure MO – death
• Mortality:
septic shock = 35-40% mortality
cardiogenic shock = 60-90% mortality
hemorrhagic = variable mortality
DETERMINANTS TISSUE PERFUSION
CO = HR x stroke volume (preload+contractility+afterload)
DO2 = CaO2 x cardiac output
VO2 = (CaO2 - CvO2) x cardiac output
O2 content = (1.38 x Hg) x O2 sat + (0.03 X PaO2 )
SVR = vessel length, blood viscosity, vessel diameter
CLASSIFICATION
1. Hypovolemic – decreased pre-load
hemorrhage/fluid loss
2. Distributive – sepsis, vasodilatory, pancreatitis,
anaphylaxis, Addison, SIRS
3. Cardiogenic – pump failure
heart, arrhythmias, obstructive
(PE, pneumotx, tamponade, pulm. hypert.)
4. Neurogenic – hypotension NOT tachyc, vasoconstriction
CLASSIFICATION
PCWP
Hypovolemic
Distributive
Cardiogenic
CO
SVR
SVO2
History Shock Resuscitation
Time
Focus
Resusc
Outcome
WW I
WW II
wound toxins
IV repletion
Vietnam
IV + EC repletion
70-80’s
organ support
none
early death
blood
ARF
colloid
blood
ARDS
crystalloid
ICU
ARDS, MOF
Trauma
QUESTION #2
Metabolic effects of the neuroendocrine response to injury
include which of the following events?
a) Gluconeogenesis.
b) Glycogen synthesis.
c) Lipolysis.
d) Proteolysis.
e) Hypoglycemia.
PATHOPHYSIOLOGY I
Hypovolemia
(decresase C.O.)
Vasoconstriction
Tachycardia
Decrease blood flow
• Splanchnic
• Loss gut barrier
• Renal redistribution
• Renin-angiotensin-aldost
Fall transmemb potential
Na-K pump
Cellular dysfunction
PATHOPHYSIOLOGY I
Intracellular water
Na=9.9
K=173
Cl=3.9
6%
Na=18.4
K=162
Cl=11.1
Extracellular water
49%
QUESTION #3
Which of the following is/are elevated during acute response
to injury?
a) Glucagon.
b) Glucocorticoids.
c) Cathecolamines.
d) Insulin.
e) Thyroid stimulating hormone (TSH).
PATHOPHYSIOLOGY II
hypovolemia
tissue injury
pain
fear
sympathoadrenal
response
catechol
BP, HR
contractility
vasoconstriction
hypoxia
endoth – macrophages cytokines, PAF, eicosanoid,
neutrophils
ROS, coagulation
reperfusion injury
SIRS/MODS
translocation
hypothalamichypophysealadrenal
response
cortisol, glucagon
hypermetabolic
state
CONSEQUENCES
1. Acidemia – low pH, lactate, BE
2. Ischemic organs
3. SIRS
4. MODS
QUESTION #4
Which of the following statements accurately characterizes
fluid shifts in hemorrhagic shock?
a) Loss of IV volume is fully compensated by interstitial fluid moving
into the vascular space.
b) Intracellular fluid volume decreases as fluid shifts from the IC
to the EC compartment to compensate for the IV loss.
c) There is movement of interstitial fluid into the IC space even though
full compensation of IV losses has not yet occurred.
d) Transmembrane potential falls resulting in increased Na permeability
and influx of Na into the cell.
HYPOVOLEMIC SHOCK
Classification
• Up to 15% (compensated)
HR<100, RR 14-20, N urine/BP, anxious
• 30% (up to 1500ml)
• 40%
• >40%
HYPOVOLEMIC SHOCK
Management
1.
2.
3.
4.
ABCDE – oxygen + 2L NS or RL
Identify source bleeding
Control bleeding
Resuscitate until perfusion corrected
Massively transfused patients
Control Bleeding - Surgery
Direct control of bleeding
- surgery
- cauterization
- topical agents
- angio-embolization
Fluids
Restore circulating volume
crystalloids vs. colloids
SAFE trial:
NEJM 2004; 350:2247
NEJM 2007; 357:874 - TBI severe 42% vs 22%
Blood
Replace blood losses
- RBC
- other blood products
TRICC trial:
NEJM 1999; 340:409
J Trauma 2004; 57:563
Crystalloid Side Effects
• Abdominal compartment syndrome
• Extremity compartment syndrome
•
•
•
•
Pro inflammatory
Increased organ dysfunction (ARDS)
Increased hospital stay
Longer ventilation days
Diffuse Coagulopathy
•
•
•
•
•
•
dilution
consumption
hypothermia
platelet dysfunction
excessive fibrinolysis
DIC (????)
Triangle of Death
massive
transfused
(10-20U RBC)
hypothermia
death
acidosis
coagulopathy
Damage control resuscitation:
• 5% massively bleeding
• Restrict crystalloids
• Reconstituted whole blood
RBC 1:1 FFP (:1 platelet)
Evidence 1FFP:1RBC
Borgman (J.Trauma 2007;63:805)
•
•
•
Retrospective chart review
246 at US Combat Army Hospital
≥10U RBC/24h (including whole blood)
mortality
1:8
1:2
1:1
65%
34%
19%
death by exsanguination
92%
78%
37%
Evidence 1FFP:1RBC
Borgman (J.Trauma 2007;63:805)
• Survivorship bias
• Crystalloids
1:8
1:1
mortality
65%
19%
crystalloids
1.8L/h
0.5L/h
Evidence 1FFP:1RBC
Kashuk (J. Trauma 2008, 65:261)
• Retrospective (Civilian - Denver)
• 133 patients; >10 RBC in 6h
• 1:1 NO survival benefit
• Crystalloids NOT risk factor coagulopathy
• Temperature risk factor (ISS ??)
Guidelines – ATLS (95% patients)
Endpoints Trauma Room
Fluid resuscitation
Endpoints
2L crystalloids
search bleeding
repeat bolus
start RPBC
blood pressure
heart rate
urine output
85% inadequate tissue O2
Current Resuscitation
Endpoints – ICU
Global
Regional
supranormal DO2
mixed venous O2 sat
RVEDV - LVP
base deficit
lactate
gastric tonometry
skin/brain blood flow
THERAPY
GOAL-DIRECTED SUPRANORMAL VALUES
Shoemaker (late 80’s)
post op, trauma pre-op patients
Boyd & Hayes (1999)
no improvement overall
reduced mortality if 8-12h (8RCT)
92% survival if achieved 24h
93% mortality if not and lactate high >24h
598 patients
• penetrating
• BP  90 mmHg
STANDARD
n = 309
• 870 cc p.h.
• 1608 cc ER
NO FLUID
n = 289
• 90 cc p.h.
• 280 cc ER
62% survived
70% survived
TIMING for fluids
1. Bleeding – surgical hemostasis
2. NO TBI – allow hypotension
HYPOVOLEMIC SHOCK
Management
1. ABCDE – oxygen + 2L NS
2. Identify & control bleeding
3. Resuscitate until perfusion corrected
Massively transfused patients
1. Blood-based resuscitation
2. Reconstituted whole blood (1:1 RBC:FFP)
3. Restrict crystalloid
QUESTION #5
Which one or more of factors determines cardiac output?
a) End-diastolic volume.
b) Afterload.
c) Contractility.
d) Heart rate.
e) Ventricular interaction.
QUESTION #6
Which factors directly affect oxygen delivery?
a)
b)
c)
d)
e)
Blood transfusions.
Oxygen consumption (VO2).
Cardiac output (CO).
Fraction of inspired oxygen (FiO2).
Metabolic alkalosis.
SEPTIC SHOCK
SIRS
Sepsis
documented infection
Severe sepsis
lactic acidosis, oliguria (<0.5ml/h), mental,
platelet <100,000, cap refill ≥ 3sec, mottled
Septic shock
hypotension despite fluids (40-60 ml/Kg)
DEFINITION SIRS
At least two of:
• RR>20 or PaCO2<32mmHg
• HR>90
• Temperature >380C or <350C
• WBC>12,000 or <4,000
THERAPY
1. FLUIDS **
2. DIAGNOSIS
3. SOURCE CONTROL
4. ANTIBIOTICS
THERAPY
1. FLUIDS **
CVP 8-12
MAP  65
U.O.  0.5cc/h
SvO2  70% (or SVCO2)
Rivers NEJM 2001
control
CVP, MAP, U.O.
0 to 6h
7 to 72h
intervention
CVP, MAP, U.O., SvO2
more fluid
more blood
more inotropes
more fluid
more blood
more inotropes
MORE DEATHS
THERAPY
5. PRESSOR (2nd line, nor, epi or dopamine)
6. INOTROPES (dobutamine)
Heart Rate Contractility Constriction
Dopamine
Epi
Norepi
Phenylephrine
++
+++
++
0
++
+++
++
0
++
++
+++
+++
THERAPY
7. STEROIDS (ACTH, low raise <9mcg/dl + hemod effect)
8. rhAPC (PROWESS = APACHE>25, MOD x2
ADDRESS = not for low risk death)
THERAPY
9. TRANSFUSION TRIGGER
10. PROTECTIVE VENTILATION
TV 6ml/k; PP<30, PEEP
11. SEDATION, PARALYSIS
12. NUTRITION, GLUCOSE CONTROL
CONCLUSIONS
1. Shock
• Definition, classification
• Overview physiopathology
2. Hypovolemic shock
• Stop bleeding then volume
• Damage control resuscitation
3. Septic shock
• Definition
• Current guidelines