1. HYPOVOLEMIC SHOCK University of Medicine and Pharmacy, Iasi
School of Medicine
ANESTHESIA and INTENSIVE CARE
Conf. Dr. Ioana Grigoras
MEDICINE
4th year
English Program
Suport de curs
HYPOVOLEMIC SHOCK

2. HYPOVOLEMIC SHOCK DEFINITION Hemorrhagic shock
syndrom characterized by decreased circulating blood volume (hypovolemia), which results in reduction of effective tissue perfusion pressure and generalized cellular dysfunctions.
Forms:
Hemorrhagic shock
Non-hemorrhagic hypovolemic shock

3. HYPOVOLEMIC SHOCK CAUSES: Hemorrhagic: Non-hemorrahagic:
External blood loss (wounds)
Exteriorization of internal bleeding (hematemesis, melena, epistaxis, hemoptysis,etc.)
Internal bleeding (hemothorax, hemoperitoneum,etc. )
Traumatic shock
Non-hemorrahagic:
Digestive losses (vomiting, diarrhea, nasogastric suction, billiary, digestive fistula, etc )
Renal losses (diabetes mellitus, polyuria caused by diuretics overdose, osmotic substances, polyuric phase of acute renal failure, etc.)
Skin losses (intense physical effort, overheated enviroment, burns, etc.)
Third space losses (peritonites, intestinal oclussion, pancreatits, ascitis pleural effusions, etc.)

4. PATHOPHYSIOLOGY Primary pathophysiological event
(reduction of ventricular filling volumes and pressures)
compensatory phenomena macrocirculatory reaction
time
decompensatory phenomena microcirculatory reaction

5. PATHOPHYSIOLOGY Hypodynamic shock: Macrocirculatory reaction:
sympatho-adrenergic + humoral reaction (ADH, cortizol, SRAA)
EFFECTS: centralisation of the circulation (compensatory effect)
worsening of tisular hypoperfusion (decompensatory effect)
Microcirculatory reaction:
Alterations of capillary exchanges
EFFECTS: transcapilary filling (compensatory effect)
capilary leak (decompensatory effect)
Maldistribution of blood flow
EFFECTS: preferential renal blood flow towards medular region (cortical vasoconstriction)
Abnormal peripheral oxygen extraction
EFFECTS: early - increased (compensatory effect)
late - decreased (decompensatory effect)
Rheologic changes
EFFECTS: ↑ blood viscosity,  blood flow, CID
Endhotelial modifications
EFFECTS: morpho-functional modifications
proinflamatory and procoagulatory status,
altered permeability

6. HYPOVOLEMIC SHOCK CLINICAL SIGNS: Intense thirst Tachycardia Tachypnea
Positive orthostatic test
Small pulse wave
hTA (blood hypotension)
Agitation, anxiety , confusion, coma
Oliguria
Cold extremities
Profuse sweating
Collapsed peripheral veins
Delayed return of color to the nail bed
+ History of hemorrhagic or non-hemorrhagic losses

7. CLASSIFICATION OF HYPOVOLEMIC SHOCK
Class II
Class III
Class IV
Blood loss- ml
< 750ml ml ml
>2000ml
Blood loss-%
<15%
15-30%
30-40%
>40%
Pulse rate
<100/min
< 100/min
/min
>140/min BP N 

Pulse wave amplitude 
Capillary refill +
Respiratory rate
14-20/min
20-30/min
30-40/min
>40/min
Urinary output
>30ml/oră
Oliguria
Oligoanuria
Anuria
Mental status
Mild anxiety
Anxiety
Confused
Lethargy

8. DIFFERENTIAL DIAGNOSIS WITH OTHER FORMS OF SHOCKHR BP CO
CVP
PAOP
SVR
Da-vO2
SvO2
Hypovolemic shock ↑ 
Cardiogenic shock 
Septic shock
↑ N
 N N

9. ABBREVIATIONS: HR – heart rate BP – arterial blood pressure
CO – cardiac output
CVP –central venous pressure
PAOP – pulmonary artery occlusion pressure
SVR – systemic vascular resistance
Da-v O2 – oxygen arterial-venous difference
SvO2 – mixed venous blood oxygen saturation

10. HYPOVOLEMIC SHOCK TREATMENT PRINCIPLES
Initial treatment of shock states
Causative treatment – STOP losses
Volume repletion
Inotropic therapy
Vasomotor therapy

11. TREATMENT OF HYPOVOLEMIC SHOCK
Causative treatment – STOP losses
essential role
surgical treatment (when appropriate)
emergency surgery for ongoing hemorrhage

12. TREATMENT OF HYPOVOLEMIC SHOCK
volume replacement
Vascular access site
Solutions for volume replacement
Rhythm of administration

13. TREATMENT OF HYPOVOLEMIC SHOCK
Volume replacement – SITE of VASCULAR ACCESS
Peripheral vascular access
Multiple access (2-4 veins)
Large peripheral catheters
External jugular vein
Advantages:
Short time of instalation
Requires basic knowledge and simple matherials
Minor complications (hematomas, cutaneous seroma, etc.)
Disadvantages:
The diameter of peripheral catheter must be adapted for peripheral veins dimensions
Vascular access can be lost (restless patient, during transportation); must be changed at hours;
no catecholamines administration (except in emergency for a short time period,until a central venous access is available)
Central venous access
After peripheral vascular access is established and volume replacement is initiated
Reliable and long lasting venous access (7-10 days)
Allows CVP measuring and guiding of treatment
Allows the administration of catecholamines and hypertonic substances
Risk of complication (at instalation – pneumothorax, cervical or mediastinal hematoma, cardiac dysrhytmias; during utilization – infection, gas embolism)

14. TREATMENT OF HYPOVOLEMIC SHOCK
Volume replacement - Solutions for volume replacement
Isotonic crystalloid solutions
Hypertonic crystalloid solutions
Colloid solutions
Whole blood and red blood cells
Fresh-frozen plasma
Platelets

15. TREATMENT OF HYPOVOLEMIC SHOCK
Solutions for volume replacement
-Isotonic crystalloid solutions
Normal saline (NaCl 0,9 %), Ringer solution, lactated Ringer solutions
Advantages:
easy available
cheap
reduced risks
Disadvantages:
Small volume effect (out of 1000ml infused solution – ml remains intravascullarly, the rest is distributed to the interstitial space)
short duration of volume effect
risk of interstitial edema, metabolic hyperchloremic acidosis
-Hypertonic crystalloid solutions
hypertonic saline (NaCl 7,4%)
Efficient blood volume resuscitation with small solution volume (water is atracted from interstitial space )
Avoidance of fluid overload and peripheral edema
may result in acute pulmonary edema

16. TREATMENT OF HYPOVOLEMIC SHOCK
Solutions for volume replacement
Colloid sollutions
Dextrans: Dextran 70, Dextran 40
Gelatines: Gelofusin, Haemacel, Eufusin
Hetastarch: Haes, Voluven, Refortan
Human albumin 5%, 20%
Advantages:
Good volume effect
Long duration of volume effect
Disadvantages:
expensive
risk for anaphylactic reactions
interfere with blood groups determination
can induce/ aggravate coagulation disorders

17. TREATMENT OF HYPOVOLEMIC SHOCK
Solution for volume replacement
Blood and blood products are not volume solutions
Only isogroup isoRh blood
Only after restauration of intravascular volume with cristalloid /colloid solutions;
For correction of oxygen transport
In case of posthemorragic anemia (after volume replacement) or ongoing hemorrhage
In case of massive blood transfusion – add fresh-frozen plasma and platelet concentrate

18. TREATMENT OF HYPOVOLEMIC SHOCK
Volume replacement
RHYTHM OF ADMINISTRATION
Rhytm of administration depends on:
Ongoing losses / stopped losses
Rhytm of losses – rapid (minutes, hours) or slow (days) instalation
For the patient with hypotension – normal saline (2000 ml in the first minutes)
after the first minutes - volume replacement continues depending on the clinical and hymodinamic parameters (BP, HR, etc..)

19. TREATMENT OF HYPOVOLEMIC SHOCK
Volume replacement –
MONITORING THE TREATMENT EFFICIENCY
Clinical parameters
normalisation of BP, HR, pulse amplitude, skin colour and temperature, mental status, urinary output
Hemodynamic parameters
Normalization of CVP, PCPB, DC, RVS, so
Laboratory parameters
Normalization of acid-base balance, liver, renal tests, Hb şi Ht, so

20. TREATMENT OF HYPOVOLEMIC SHOCK
Inotropic support
Only after volume replacement
Used to improve cardiac output
Dobutamine
inotropic positive support
peripheral arterial vasodilatation

21. TREATMENT OF HYPOVOLEMIC SHOCK
Vasopressor therapy
NOT RECOMMENDED (may aggravate peripheral hypoperfusion and metabolic acidosis)
EXCEPTIONS
Only temporary
In case of ongoing hemorrhage, which outruns the possibilities of volume replacement
Only until surgical procedure stops the hemorrhage (emergency surgical treatment)
Noradrenaline, dopamine, adrenaline