SHOCK AND RESUSCITATION - depts.washington.edu depts by ert554898

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									            SHOCK AND
          RESUSCITATION

     Hugh M. Foy, MD
Harborview Medical Center
 University of Washington
         Shock and Resuscitation
Goal: understand the pathophysiology of shock
               and it’s treatment

• Objectives:
  – Be able to categorize types of shock
  – Understand mechanisms of adapting to
    volume loss of blood loss
  – Demonstrate shock treatment:
    • lines, sites, types of fluid
    • End points of resuscitation
    • Complications of treatment
         SHOCK: Definition
• Commonly misused
  – “psychogenic”
  – Webster: 12 different definitions
     • 4: “the state of profound depression of the vital processes
       associated with reduced blood volume and pressure and
       caused usually by severe esp. crushing injuries,
       hemorrhage, or burns.”


  “The rude unhinging of the machinery of life” Gross 1872
           Types of Shock
• “Classic”   Blalock 1937

  –   Hematogenic
  –   Neurogenic
  –   Vasogenic
  –   Cardiogenic
       Classification of Shock
•   Low Cardiac Output states
     – Hypovolemic shock
         • volume loss
         • Internal volume loss
     – Cardiac shock
         • Impaired inflow
         • Primary pump
           dysfunction
         • Impaired outflow
     – Low peripheral resistance
       states
         • Neurogenic shock
              – Loss of sympathetic
                tone
         • Vasogenic Shock
              – Septic
              – Anaphylactic

                        Carrico: ACS Early Care of the Injured Patient 4th Ed.
   The Circulatory System
• Components:
  – Heart (pump)
  – Blood Vessels
  – Blood
              Circulation and
                 Electricity
• Circulation
   – The flow of blood
• Electricity
   – The flow of electrons
• Ohms law: V= IR
   (Voltage = Current x
     Resistance)
   BP = CO x SVR
      • (Cardiac Output x System
        Vascular Resistance)
    Circulation Schematic

• The Pump (heart)
  – 2 sided
     • Anatomically looks
       parallel, BUT:
     • Physiologically and
       in Actuality
        – Supplies 2
          systems
          connected in
          series
The Heart:

                2-Sided Pump
  • Right Side
     – Compliant, flexible
     – Low pressure,
       variable volume
  • Left Side
     – Stiff, strong
     – High pressure,
       fixed volume

             Like the colon?
    The Circulatory System
• Multiple Parallel
  Circuits
   – Organized
     teleologically:
      • Prioritized supply
          – Closest circuits get
            supplied first and
            foremost
              » Coronaries,
                 Brain, Kidneys
          – Distal circuits get
            shut down when
            volume low
              » Gut/Muscle,
                 Skin
                Circulatory Control
                   Mechanisms
•   Closest, fastest
     –   Carotid Bodies (Baroreceptors)
          •   Stimulate Sympathetic Nervous
              System
•   Mid-level
     –   Kidneys- Juxtaglomerular
         Apparatus
          •   Sense low flow and stimulate
              Renin resulting in
              vasoconstriction (splancnic)
•   Down-line
     –   Adrenal Cortex
          •   Senses need for more Sodium
              and Fluid Re-absorbtion to deal
              with upright posture volume
              needs
SHOCK


              Acute Volume Loss
  • Shock - Classes:

        I       0-15% blood loss
        II      15-30%        blood loss
        III     30-40%        blood loss
        IV      >40% blood loss
    Response to Volume Loss
Type % blood loss   HR     BP    Postural   Cap Ref


•   I   0-15%       nl     nl     maybe       nl
•   II 15-30%       +      maybe   yes        nl
•   III 30-40%      +++    decr   moot       incr
•   IV    >40%      ++++   <60Sys  “         incr
 Shock Resuscitation Study
                      Shires, et al
• Bled dogs 40% blood
  volume
  – 100% mortality
    untreated
• Bled, then gave back
  blood
  – 80% mortality
  – Autopsy study
     • Swollen muscle cells
       despite total volume
       loss
     • Tagged RBCs, Na+,
       K+, Alb., and repeated
       the experiment
Shires Shock Study


                     Results
  • Na+ leaked into cells
  • K+ leaked out of
    cells
  • Albumin leaked into
    interstitial space
  • Water followed Na+
  • Translocated fluid 3
    times the shed blood
  • Measured
    composition of
    transloc. fluid
Shires Shock Study


                Conclusions
   • Translocated Fluid composition is LR
   • Inadequate O2 delivery shuts down Na+/K+
     pumps, making cells leaky

   • Repeated the Experiment:
      – Gave Shed Blood plus 3 times volume of LR
         • Mortality decreased from 80 to 30%
          Treatment of Shock
• Recognize Type of
  Shock
       • If definite pump failure
         and cardiogenic shock
         institute cardiac
         protocols
• Otherwise: 2 large bore,
  upper extremity      lines
  and:
   – Volume
   – Volume
   – Volume
When in doubt, try a little
  more volume
        Treatment of Shock
• Goal: Restore
  perfusion
• Method: Depends on
  type of Shock
  – Basically 2 kinds:
     • Hypovolemic
       (hemorrhagic, septic,
       neurogen.)
     • Cardiogenic
       (Impedence or primary
       Cardiac Failure)
            Treatment:
         Cardiogenic Shock
• Oxygen by nasal cannula
• IV access
   – Pain medication
   – Nitrates prn-
      • may need unloading only
        after volume status
        addressed
   – Treat arrythmias
   – CPR as needed
      Treatment of Shock
• Prioritized approach
• Must address and treat sequentially:
  – PRELOAD
  – AFTERLOAD
  – PUMP
• QUESTIONs:
  – What type of fluid
  – How Much
  – End Point of Resuscitation
       Resuscitation Fluids
•   Blood
•   Lactated Ringers
•   Normal Saline
•   Colloids
•   Hypertonic Saline
•   Blood Substitutes
    Treatment: Hemorrhagic
            Shock
• Large bore access
   – 2 upper extremity IVs
   – 16 gauge or larger
• Bolus therapy
   – 20 cc/kg
   – Adults- 2 liters
• Monitor Effect
• Repeat if necessary
• After 2nd bolus: need
  blood txn
   – 10cc/kg
    End Points of Resuscitation:
• Restoration of normal vital signs
• Adequate Urine output
    – 0.5 - 1.0 cc/kg/hr
•   Tissue Oxygenation measurement
•   Adequate Cardiac Index
•   Normalization of Oxygen delivery DO2I
•   Normal Serum Lactate levels

none proven helpful, some deleterious

Englehart; Curr Op Crit Care; Vol 12(6), Dec 06, p 579-574
    Evolution in Treatment
          Strategies
• Auto transfusion (“Cell Saver”)
• Hyperdynamic “Supranormal”
  Resuscitation (Shoemaker)
• Less is More - Mattox
• Trauma Vaccine - Vedder, et al.
• Hypertonic Saline
• Glue Grant-
  – standardization, endpoints, genetics
Alternatives to Transfusion:
• Autotransfusion
  – Safe, warm, better 2-3
    DPG levels
  – Coagulation factors
    present
  – 2 methods
     • Passive collection and
       anti-coagulant (chest
       tubes)
     • “Cell Saver”- washes
       Red Cells
         – Contamination and
           Time issues in
           trauma




•Expensive, fussy, too slow in trauma,
•Okay in elective, clean cases
        Hyperdynamic
  “Supranormal” Resuscitation
 • Swan Ganz Catheter
 • Measure ratio of O2 delivery
   and consumption
 • Push fluid resuscitation until
   no longer “flow dependent”
 • Massive Edema can be lethal
     – (DaNang Lung, ARDS, MSOF, SIRS,
       Abdominal Comp. Syn.



Multiple synergistic factors: some influenced by ventilator strategy
                     Mattox in Houston
                    Q: Is less fluid better?
• Randomized pts. QOD
         • LR vs 250 cc. Hypertonic Saline/Dextran
         • 3% increase in survival in HSD (not significant)
         • Trend in increase survival in penetrating trauma
           victims only
         • Prospective trial showed only a trend in
           improvement, with low n of 48 pts
         • May be beneficial with head injuries only

•   Ann Surg 1991;213:482-491
•   Am J Surg 1989;157:528-34
“We’ll see”
          Trauma Vaccine Trials
• Shock-
“Ischemia-Reperfusion Injury”
    * WBCs “up-regulated”
           adhere to endothelium
    * Damaged endothelium leaky
          Create massive edema
Blocking adherence -mAb 60.3
    -neutropenia protective against ARDS
    - WBC surface adhesion molecules when blocked
    decreases the edema and injury
          - animal data encouraging
Human Trials unsuccessful

Vedder, et al: Blood, 15 2002, Vol 100, No. 6, pp 2077-80
HYPERTONIC SALINE WITH
    DEXTRAN (HSD)
     7.5%saline with 6% dextran-70
• Less volume and
  weight to carry
• May reduce mortality
• Limits secondary
  brain injury
• Less activation of
  inflammatory cells
           Harborview Study
• Double blind, randomized study
• N = 209
• Endpoint: ARDS free survival
   – 250 ml 7.5% HTS/ 6% Dextran70 vs LR
• Findings:
   – No difference in population overall
   – Improvement in sickest patients (19%)
       • > 10 units PCs required

• Bulger et al: Arch Surg. 2008; 143(2); 139-148
Shock-Treatment Algorithm
Transcutaneous O2 Sat
     Monitoring
   Tissue Oxygenation Measurements
                                          *StO2 <75 severe shock

                                                 78% MODS
                                                 91% Dead
                                              StO2 <75% in 1st hr.

                                          * StO2 >75
                                               88%
                                            MODS free survival

                                          Similar to Base Deficit
                                          measurement
Cohn SM, Nathens AB, Moore FA, Rhee P, Puyana JC, Moore EE, Beilman GJ.
J Trauma. 2007 Jan;62(1):44-54; discussion 54-5.
         Blood Transfusion
• Blood Banks safer
• Some risk
  unavoidable
   – New viruses are
     inevitable
   – False negative
     screening tests
• Independent risk
  factor for MSOD
• Time for cross-match
  delays Rx
The Search for
  Alternatives continues
Alternatives to Transfusion:
• Blood Substitutes:
  – Immediately available, storage easier, no need
    for compatibility testing, disease free
  – Polymerized, Stroma-free Hemoglobin
     •   50 gm in 500 ml
     •   No adverse effects up to 6 units
     •   Slight increase in Bilirubin
     •   Studies small, more needed
                       Gould:J Am Coll Surg 1998: 187:113-122
Shock and Resuscitation:


                     SUMMARY
  •   The Circulation is a Circuit
  •   Volume is most often the answer
  •   Lactated Ringers still the standard
  •   More is better than less, maybe
  •   New techniques:
      – Hypertonic Saline-
         • okay in Head Injury
         • Less immunosuppression
         • Helpful in the sickest patients
      – Better Indicators & Endpoints of Resuscitation

								
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