Shock is defined as
o Any condition wheren there's decreased tissue perfusion
 That lower tissue perfusion
 Tonicity of blood vessel wall (decreased tonicity) esp of
the artery


Types of shock with dec tonicity
 Neurogenic shock
 Septic shock
 Early - dec tonicity of the blood
vessel wall due to toxin being
secreted by bacteria (endotoxin)
 al
 late
 Anaphylactic shock - allergic reaction
 Hypovolemic - Most important factor in
surgery; decrease in blood volume leads
to hypotension; blood vol -- lose fluid
content --dec BP
 Hemorrhagic shock
Function of the Heart
 If malfunctioning of myocardium esp ischemia,
atherosclerosis of coronary artery ---low CO
 Cardiac compressive shock - pericardial
tamponade
 Heart is normal
 Pericardial cavity is filled up with blood -effusion --limiting distension of ventricle
during diastole --so CO is also low --blood clogged in venous side of circulation
 Patient of a surgeon now
Different Types of Shock
o
Hypovolemic shock --lose volume of blood
 Hemorrhagic shock
 Low preload - than you'll have low CO; low systemic
arteriole pressure; sensed by the carotid sinus, by atrial
receptors, and receptors in kidney
 Now stimulates hypothalamus
 Could also directly stimulate the adrenal medulla
by passing the pituitary causing release of
epineph and noreph --stimulation of heart to
compensate --tachycardia
 Epi and nor also cause vasoconstriction -inc. vascular resistance
 If you touch extremity of injury,
it's cold ---artery is constricted
 Traumatic shock
 Almost same as hypovolemic shock
 In addition, there's an injured tissue/organ; there are
immediate release of mediators (cytokines) ---increases
intravascular coagulation --clogging of blood in that area



Most mediators causes vasodilatation
Inc seepage of plasma outside of blood vessel
Remove dead tissue in brain to remove
cytokines; dead cells secrete these mediators
 With help of monocytes, t cells

Cardiogenic Shock
 Pertaining to the function of heart that's no longer
domain of surgeons
 Pumping action of heart fails; blood clogged behind the
heart
 Preload aread elevated
 Surgery onlyl participates if need for us to improve
perfusion of heart muscle ---cardiac bypass ---use
saphenous vein to bypass obstruction of coronary artery

Cardiac Compressive Shock
 Heart is normal
 But low cardiac return due to extrinsic compression of
heart
 Pericardial cavity filled up with fluid in case of
infecti --pericarditis
 Filled with blood in case of blunt or penetrating
trauma (stab/gunshot) aka pericardial
tamponade

Septic




Neurogenic Shock
 Loss of arterial and venous tones
 Tonicity of veins also decreased
 Pooling of blood in the peripheral venous system
esp in splanchnic vessel ---veins of the GIT tract
 Pooled there
Shock
Due to effect of toxin being released by the bacteri
If gram + , then exotoxin release
If gram -, then endotoxin released
Cellular Changes in patients body if perfusion of blood not optimum
o If you have hypotension, it causes death to the cell because
 Due to heme part of hemoglobin carrying O2 (in cytoplasm of
RBC) not being carried to tissues
 2 organs to maintain good oxygen level
 Brain
 Heart
 Why there's redirection of blood from other tissues to
these 2
 The oxygen is the end electron receptor of ETC (electron
transport chain)
 If you don't have O2 there, than entire ETC chain
stopped (to produce ATP)
 Aerobic metabolism - using glucose
 36 - 2 = 34
Anaerobic metabolism
 8-10 only
 Most metabolism in cell are active processes; so you
need ATP for it to work
Na K membrane pump
 Active process seen in cell membrane
 Continues to pump Na out and pump K in
 If doesn't work, Na continues to enter and small K out
 If Na in, drags in water (too much Na out; if
pump not work, Na keeps going in dragging in
water) ---resulting to cellular swelling ---cell dies
----brain dies

o
Renal response
o If you lose blood, one of the organs
 Perfusion of glomerulus goes down
o Kidney can survive 15-90 minutes if you put kidney in cold temp
 Immersed in ice bag area
 Prolonged hypoperfusion of kidney
 Functional/anatomical changes ---azotemia (elevated
creatinine)
 Important for surgeon to know whether azotemia
 Preload - treat by giving blood and fluid
 Kidney parenchymal damage - don't give
fluid; kidney already working ---kidney
edema
 Poor perfusion of glomerulus
 Use Renal Failure Index to see if preload
 Na of urine
 And plasma creatinine
If < 1, prerenal oliguria
 Kidney still functioning,
poor perfusion of
glomerulus; give fluid
If > 1 acute renal failure (24 hrs)
 Have to give fluid
simultaneously with
antidiuretics; if keep giving
fluid, pt might die of
pulmonary edema
Pulmonary response
o Damage alveolar-capillary interface
 Acute diffuse lung injury
o Seepage of fluid entering the interface
 Alveoli
 Due to mediators, plasma will now fill up the interface, making
it wider; so the O2 transport from alveoli goes to capillary that
will link to hemoglobin not optimum ---hypoxia ---big gap btw
alveolar line ep and epithelium of capillary
 Leekage of proteous fluid into interstium and alveolar space
o
Acute




respi distress syndroome
Oxygen won't go to alveoli
Pt goes to hypoxia
Dec pulmonary compliance
High airway pressure to attain adequate tidal volume
o
Multiple organ failure
 Kidney and lungs
Pathophysiology of Shock
o Hypovolemic -- most common
 Hemorrhagic most common
 Lose blood from the venous side (50%); veins more
superficially located
 If artery involved, pt will most likely die
 Decrease cardiac return
 Low CO
 Low blood pressure

Important of doctor to tell what stage hemorrhagic
shock
 Mild - lose < 20 % of blood loss
 5 liters time .20 ---if lose < 1 liter of
blood, there will be compensation -release of E NE, adrenergic constriction of
blood vessel; cold skin
 Thirsty - good clue that pt in shocking
condition
 Remember bp, pulse rate normal; urine
normal
 Constriction of blood vessel --cold
extremity
 Moderate
 20-40% blood vol lost
 Eiters
 Cold extremity
 Bp still normal, but pt will start to have
low urine output due to aldosterone and
antidiuretic hormone
 Severe
 >40% of blood vol lost
 Only time that bp of patient goes down
 Signs of MI
 Q waves and depressed St
segments
 Why surgeon always ask pt if cold arm, and asks
for urine measurement
Compensatory Mech
o Adrenergic discharge - to compensate to have higher bp
o Hyperventilation
 What happens - you inhale and exhale rapidly
 Longer inhalation and faster exhales
When inhale, thoracic pressure goes down so that lungs
will expand; higher respi rate, longer time of having dec
thoracic pressure - helps venous blood to go from
periphery to go to right side of heart -- better cardiac
return ---better cardiac output
Pt will collapse
 Oxygen level of brain not optimal -- unconscious
 If lie down, better return of blood to heart not against gravity
 Have to elevate the lower extremity

o
o
Release of fluid from interstitium into intervascular space
 In case of shock, inc epinephrine --causes constriction (pre
capillary sphincter);
 True capillaries - carrying fluid oxygen to cell; brings
waste product of cell back to blood
 Vascular shunt -- bypasses the tissue/cell
 Between shunt and true cap, you have
precapillary sphincter; in shock, epinep causes
constriction of sphincter; so instead of going to
tissue, goes to vein and back to heart
immediately
 If that happens, hydrostatic pressure decreases
so hydrostatic pressure in intercellular space
(15%) could go from half side of capillary to
replenish fluid --so better cardiac return
o
Vasoactive hormones and catabolic hormones (catabolize carb, pro,
lipid resulting glycogen to glucose, amino acid,; small solutes; now go
to intercellular space by exocytosis; goes out and oncotic pressure will
increase
 Inc oncotic pressure, by osmosis (40% of our fluids inside cell);
now getting fluid coming from intracell compt to supply
decrease of fluid in vessel
 So neuroendocrine system is reason why you have normal bp
for mild and moderate shock
 But in severe, it can no longer compensate
o
Inc hydrostatic pressure forcing water and protein to go to lymphatics
and replenishing the plasma of the patient
o
Function of kidney
 Important
o
Decompensation of hypovolemic shock
 Relaxation of arteriole, pre capillary spasm
 Instead of constricting pre cap, it now relaxes --bad
 Deterioration of cell membrane function
 Na K pump no longer working; cell dies
o
2 most sensitive signs of hypovolemia
 Cutaneous vasoconstriction
 Oliguria

Most pts usually are alcoholics -- alcohol causes vasodilatation
and inhibits secretion of ADH
 Instead of oliguria, pt will have polyuria
 Smell alchol in breat, put central venous pressure to
check if pt has been corrected or still needs fluid
resucitation
Monitoring Pt In case of shock
o Admit pt
o Have to put 2 or 3 lines and have to use a wider gauge needle (gauge
16,18,19)
o Don't give D5LR, D5NMS
 Better use lactate without dextrose
 Plain NSS witout dextrose  Dextrose causes osmotic diurses
o Put a folicatheter -- monitor urine output hourly
 Normal urine output -- 30 ml/minute (low limit); if lower than
that, then oliguria
 In book 1 ml / minute = 60 ml
 For neonates,
 2.5 ml / minute
o If elderlly, check heart status
 Kidney function --serum, creatine and bum
o
Treat injured tissue or organ
 If need for patient to receive whole blood or packed RBC,
carries O2
Management
o Correct dehydration --give crystalloid
o Disadvantage of giving colloid
 Post resuscitation of HPN
 Inc intravascular volume at the exp
 Depression of albumin synthesis
 Dep of circulation immunoglobulin
 More expensive and less easier to titrate
Position of Patient
o Fowler position - put the foot down; fowler foot - foot down
o Trendulemburg -- put the head down
 Supine and elevate the leg
 Not good they said now; increasing venous return, but
abdominal organ is also pressing the diaphragm so inhalation of
pt compromised; so best position is
o Supine Position
 Elevate lower extremity
If old
o
o
Check heart
Arrythmia -- put in ICU --
Steroids not indicated in case of shock
O2 inhalation but correct vascular volume
o If low RBC, won't work
Causes of Refractory Shock
o Continuing blood loss
o Inadequate replacement of fluid
o Massive trauma or derangement -- just correct fluid but didn't do
debrigma of organ; if still injured, organs will form cytokines; so you
remove dead tissue
o
o
In elderly, heart didn't compensate much --heart failure
Infection -- community acquired (outside bacteria); sensitive to
antibiotic
 If pt stayed in hospital for week, bacteria is now hospital
bourne; resistant to drugs
Traumatic Shock
o Lose blood (plasma)
o In addition, presence of injured tissue (traumatized) -- secretes
mediators which inc pulmonary vascular resistance due to tumor
necroting factor and interleukin 1 - vasoconstriction of pulmonary
vessle
 Inc seepage of fluid; pt perfusion down due to third space loss
(fluid enters into nonfunctional compartment)
 Have microthrombi esp cytokines
o
Treatment
 Have to correct fluid, hypovolemia and debridement - remove
cytokine source
Cardiogenic Shock
o All signs and symptoms of MI
o Increased central venous pressure; blood clogged on right side of
heart
 Put catheter at superior vena cava; make incision in basilic
vein; put catheter and it will end in superior vena cava
 Normal 8-10 cm water
 If < 8, preload down
 Cardiac return not good
 If > 10, preload elevated
 Clogging on the right side of hear
 So incase of hypovolemic, hemorrhagic shock it will be
decreased - lose blood --preload not good ---so < 8
 In cardiogenic shock, elevated due to clogging
 Picture of heart and superior vena cava description
 Put catheter and it ends in sup vena cava; 8-10 < where
water should be
o
o
o
Catheter placed even in pulmonary artery but it's expensive
Put in ICU, give analgesics to relieve pain (major stimuli)
Monitor cardiac function of pt
 Arrythmia - give digitalis, dopamine, etc
o
o
If CO not optimum, refer to cardiologist to place pacemaker
Cardiologis will refer pt for invasive cardio to chec, status of coronary
artery if there's need to do bypass operation
Cardiac Tamponade
 Decreased cardiac compliance on right atrium
 Dec
 Heart not receiving optim blood during diastole - cannot dilate optimally
 Cardiac Signs and symptoms
o Neck vein engorgement
o Distant heart sound (caused by valve closure); if blood not optimum
closure of valves are low
o If cardiac return low, low CO --- hypotension
 Other signs
o Tachycardia, oliguria, cold
o Pulsus paraoxicus - when you inhale, your pulse pressure will be
higher becaue inhalation --- thoracic pressure lower --venous return -so better CO - normal
 But pulsus, when you inhale, filling pericardial cavity - low
ventricular expansion --- so it becomes low pressure

Diagnosis
o Clinical presentation
o History of injury
o Cardinal signs
o Water bottle shape -- req for chest xray

Management
o Bring pt to OR
o Do an anterolateral trachotomy -- depress pericardial cavity --remove
blood there and fix whatever trauma done --cardiac return better -better CO
Emergency
o Use pericardiocentesis
 Use spinal needle; connect it to wide barrel syringe; palpate for
sternum (costal angle) left side; put needle 45 degrees directed
to left shoulder; hook the needle to ECG machine; if you insert
you won't hit the lung due to lingula of the left lung; resistance
of skin, muscle -- no more resistance --now in pericardia;
cavity --pull the plunger == if blood there, aspirate the blood -to make sure in cavity -- push farther after the five; look at
ECG -- if pure RS pronounced -- you're hitting the ventricle -so you pull the needle back out a bit == now you're back in the
right space
 Improves neck vein engorgement
 CO better -- hypotension lessens
 therapeutic
o If no recurrence, just observe the patient; sometimes injured vessel
damaged already


Septic Shock
o Caused by bacterial infection
 Gram positive --exotoxin
o
o
o
o
o

Gram
Usual


Gram negative - endotoxin
negative sepsis more common in surgical pts
source
Genitourinary tract --put folicatheter
Respiratory - pts who've had abdominal surgery; contraction of
diaphragm limited by pain; expansion of basal lobe not
optimum -- atylectesis - pneumonitis ---pneumonia
 Why in ab surgery, tell pt to have pulmonary therapy -deep breathing, nebulization -- to prevent problem in
respi
 Alimentary
 Integumentary
Early Septic Shock
 Have a warm extremity
 Normovolemic
 Only symptoms
 Hypotenision - due to vasodilatation from endotoxin --have dec CO with minimal resitance, inc heart rate, inc
contractility
 Bp of patient -- due to vasodilatation
 Decreased tonicity
Late Septic Shock
 If doctor failed to catch the sepsis, cold extremity
 Pt start to have hypovolemia --inc seepage of fluid outside
blood vessel - -third space loss
 Cause of hypertension
 Inc vascular permeability
 Decrease cardiac output due to in pulmonary vascular
resistance
 Inc peripheral resistance -- cold cyonotic extremity
 Inc peripheral pressure
Treatment
 Identify organ/tissue where infection coming from
 Replace fluid - in late septic - lose fliud from dec CO and third
space loss
 Requesting for culture and sensitivity
 Culture - id bacteria
 Sensitivity -- antibiotic where bacteria is susceptible

Early sign of gram - infection
 Hyperventilation
 Respiratory alkalosis
 Altered sensorium of patient
Neurogenic Shock
o Seen in spinal cord injuries
o Pt normovolemic and sometimes hypovolemic
o Pooling of blood in systemic venules --CO not good -- pulled in
splanchnic area due to spinal cord injury
o Only type of shock wherein you're justified to give vasoconstrictor
immediately
 Decreased tonicity of artery -- so just improtve tonicity by
giving vasoconstriction
o
Treatment
 Give fluid
 Give vasoconstrictor --have to give it
 To improve Cardiac return, elevate the lower extremity