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
HYPOVOLEMIC SHOCK
DEFINITION
 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
HYPOVOLEMIC SHOCK
CAUSES:
• Hemorrhagic:
 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.)
PATHOPHYSIOLOGY
Primary pathophysiological event
(reduction of ventricular filling volumes and pressures)
compensatory phenomena
time
decompensatory phenomena
macrocirculatory reaction
microcirculatory reaction
PATHOPHYSIOLOGY
Hypodynamic shock:
 Macrocirculatory reaction:
• sympatho-adrenergic + humoral reaction (ADH, cortizol, SRAA)
o EFFECTS: centralisation of the circulation (compensatory effect)
worsening of tisular hypoperfusion (decompensatory effect)
 Microcirculatory reaction:
• Alterations of capillary exchanges
o EFFECTS: transcapilary filling (compensatory effect)
capilary leak (decompensatory effect)
• Maldistribution of blood flow
o EFFECTS: preferential renal blood flow towards medular region (cortical
vasoconstriction)
• Abnormal peripheral oxygen extraction
o EFFECTS: early - increased (compensatory effect)
late - decreased (decompensatory effect)
• Rheologic changes
o EFFECTS: ↑ blood viscosity,  blood flow, CID
• Endhotelial modifications
o EFFECTS: morpho-functional modifications
proinflamatory and procoagulatory status,
altered permeability
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
CLASSIFICATION OF HYPOVOLEMIC
SHOCK
Class I
Class II
Class III
Class IV
Blood loss- ml
< 750ml
750-1500ml
1500-2000ml
>2000ml
Blood loss-%
<15%
15-30%
30-40%
>40%
Pulse rate
<100/min
< 100/min
120-140/min
>140/min
BP
N
N


Pulse wave
amplitude
N



Capillary refill
N
+
+
+
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
DIFFERENTIAL DIAGNOSIS
WITH OTHER FORMS OF SHOCK
HR BP
CO
CVP




↑
↑


↑
↑
↑
↑

N


↑
Hypovolemic
shock
↑
Cardiogenic
shock
↑ 
Septic shock
↑
 ↑N N
PAOP SVR
Da-vO2 SvO2
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
HYPOVOLEMIC SHOCK
TREATMENT PRINCIPLES
• Initial treatment of shock states
• Causative treatment – STOP losses
• Volume repletion
• Inotropic therapy
• Vasomotor therapy
TREATMENT OF HYPOVOLEMIC SHOCK
• Causative treatment – STOP losses
– essential role
– surgical treatment (when appropriate)
– emergency surgery for ongoing hemorrhage
TREATMENT OF HYPOVOLEMIC SHOCK
• volume replacement
– Vascular access site
– Solutions for volume replacement
– Rhythm of administration
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 24-48
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
Advantages:
– Reliable and long lasting venous access (7-10 days)
– Allows CVP measuring and guiding of treatment
– Allows the administration of catecholamines and hypertonic substances
Disadvantages:
– Risk of complication (at instalation – pneumothorax, cervical or mediastinal hematoma, cardiac
dysrhytmias; during utilization – infection, gas embolism)
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
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 – 250-300ml 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%)
• Advantages:
– Efficient blood volume resuscitation with small solution volume (water is atracted
from interstitial space )
– Avoidance of fluid overload and peripheral edema
• Disadvantages:
– may result in acute pulmonary edema
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
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
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 15-30 minutes)
– after the first 15-30 minutes - volume replacement
continues depending on the clinical and hymodinamic
parameters (BP, HR, etc..)
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
TREATMENT OF HYPOVOLEMIC SHOCK
• Inotropic support
– Only after volume replacement
– Used to improve cardiac output
– Dobutamine
• inotropic positive support
• peripheral arterial vasodilatation
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