Shock

B. Mladosievicova

Definition

State of acute generalized circulatory failure causing inadequate tissue perfusion

The effects of shock are initially reversible,

but rapidly become irreversible, resulting

in multiorgan failure (MOF) and death

Shock left untreated may be

fatal.

It must be recognized and

treated immediately

Shock at cellular level

• oxygen delivery to the cells is not sufficient to sustain cellular activity

• the central role of microcirculation in providing oxygen to the cells

Microcirculatory dysfunction leads to

• dysfunction of cell membranes, breakdown of cellular metabolism

• Reduced oxygen and nutrients delivery in cells – LA – decreased cellular pH- release of strong enzymes, RMO – loss of cell integrity – loss of cells in brain, heart– irreversibility of shock

Finfer SR,

NEJM 2013

Activating hematologic system

Activating CVS

Activating renal system

5/11/2017 10

Hypovolemic Shock

Hemorrhagic/Traumatic

Blood (external, internal)

Fluid (GIT,kidneys...)

Plasma - burn

increased: Hb, Ht, plasma proteins -

from haemoconcentration

The most common causes of HS

External blood loss: penetrating trauma, GI bleeding disorders

Internal blood loss: organ injury, abd. aortic aneurysma

Hypovolemic shock -phases

• Compensation (latent)

• Decompensation

• Irreversible

Compensatory period able to compensate blood loss to 20%

• Releasing of catecholamines

• Constriction of arteriols and veins, shift of blood to arterial region

• Centralisation of blood to heart and brain from splanchnic tissues, skin, kidneys (activation of RAAS – retention of Na, water, increased osmolality, releasing of ADH - oliguria), decreased HP, higher oncotic pressure in capillaries

Hypoperfusion – ischemic triggers releasing of

TNF-alpha, IL-1,IL-2,IL-6,IL-8. Metabolites of arachidonic acids,

lysosomal ee,, vasoactive mediators (k, h, s)

Decompensation

• If centralisation longer than 1-2 hours

• If blood loss is more than 20-30%

• METABOLIC FAILURE OF CELLS - MA

Blood loss BP(mmHg) Heart rate (bpm) Diuresis 10-15% normal normal normal

15-30% <100 > 100 oliguria

30-40% < 90 > 120 anuria

Shock starts when

systolic BP<100 and heart rate >100

Hypovolemic = decreased circulating volume

hypotension (rapid 25% volume loss)

rapid pulse (measurable on a. radialis means 90 SBP,

only on a.carotis 70 SBP)

Compression of nail (more than 5 s – means

hypoperfusion)

tachypnea

anxiety

irritability

• reduced level of consciousness - apathy

- coma

• oliguria - urine production less than 400ml/d

• cool skin, pale, thirst, hypothermia

Blood loss

• Closed femoral fracture 300-2000 mL

• Closed costal fracture 150 mL pre each

• Closed fracture of tibie 500 mL

• Open wound 10x10 cm 500 mL

• Haemothorax 2000mL

• State of circulation is modified by fear, cold, pain!!!

Cardiogenic shock

is a life-threatening condition that occurs in

response to reduced cardiac output in the

presence of adequate intravascular volume

and results in tissue hypoxia

Cardiogenic shock

hypoperfusion is usually associated with

increased central venous pressure,

hepatomegaly can be clinically apparent

CARDIOGENIC SHOCK - MI (7% of pts),

heart failure,

arrhythmias

Decreased contractility- reduced cardiac output –

decreased coronary perfusion- further ischemia- necrosis

SBP <90 mm Hg persistent more than 30 min.

urine output < 20 ml/HOUR

peripheral vasoconstriction – oliguria, cool ext.,pale skin...

impaired mental status

ECG, invasive haemodyn. monitoring

Spiral of cardiogenic shock

Management of PTS with cardiogenic shock

- improving myocardial contractility (inotropy –

dopamine…)

- decreasing afterload (vasodilators)

- increasing myocardial oxygen supply

- decreasing “ “ demand

- correcting hypoxia, met. acidosis

- diuretics

- mechanical assist devices – intraaortic ballon pump

reduction of pain, anxiety

5/11/2017 12

Obstructive Shock

Massive pulmonary

Embolism

Cardiac Tamponade

Dissecting of aorta or

aneurysma

Aortic stenosis

11/24/2016 11

Distributive Shock

caused by loss of vasomotor controlvolume remains unchaged, vascular bed

enlarges, CO is high

Septic (mainly – LPS of G negative bact. -

peritonitis, abscess, pneumonia) ATB

Anaphylactic (massive Ag-Ab reactions

no more than 1-2 hours after exposure)

EPINEPHRIN

Neurogenic (sympathetic tone loss –

vasodilation- decreased venous return –

hypotension, bradycardia) ATROPINE

S SEPTIC SHOCK

M (sepsis + hypotension)

- SEPSIS -

systemic inflammatory response syndrome (SIRS)

induced by infection – old definition

Sepsis should be defined as life-threatening organ

dysfunction caused by a dysregulated host response to

infection. For clinical operationalization, organ dysfunction

can be represented by an increase in the Sequential [Sepsis-

related] Organ Failure Assessment (SOFA) score of 2

points or more, which is associated with an in-hospital

mortality greater than 10%.

•

Septic shock

• a subset of sepsis in which particularly profound circulatory, cellular, and metabolic abnormalities are associated with a greater risk of mortality than with sepsis alone.

• trauma, surgical pts

• DM

• malignancies (+ immunosupressive therapy)

• cirrhosis

• urinary tract, GI infections

• newborns

• in the elderly

SIRS (at least 2 signs)

• > 38°C or <36°C

• tachycardia > 90 bpm

• tachypnoe > 20/min or PaCO2 < 4.3 kPa

• Le > 12 x 109/l or < 4 x 109/l

Infectious Noninfectious

bacterial diabetic complications cholecystitis pneumonia urogenital meningitis etc.

acute intestinal ischemia pancreatitis autoimunne diseases burns aspiration drug reactions cocain/amphetamine MI

Causes of SIRS

Septic shock develops in less than one half of patients with bacteremia. It occurs in about 40% of those patients with gramnegative bacteremia and about 20% of patients with Staphylococcus aureus bacteremia.

Septic shock

• Fever

• Chills

• Sweating

• Altered mental status

- Anxiety

- Agitation

• Head and neck infections - earache, sore throat, sinus pain or congestion, nasal congestion or exudate, swollen

lymph glands • Chest and pulmonary infections - cough (productive),

pleuritic chest pain, dyspnea

• Abdominal and GI infections - abdominal pain, nausea, vomiting, diarrhea • Pelvic and genitourinary infections - pelvic or flank pain,

vaginal or urethral discharge, dysuria, frequency, urgency • Bone and soft tissue infections - focal pain or tenderness,

focal erythema, edema

Management of pts with clinical

signs and symptoms

Ventilation Infusion Pump function

COMPLICATIONS OF SHOCK

IF PERFUSION PRESSURE IS < 50 mm Hg

BRAIN DEATH

FOCAL MYOCARDIAL NECROSIS, HF

CONGESTION OF SPLEEN

STRESS ULCERS IN STOMACH

VASODILATION AND SPLANCHNIC POOLING

NECROSIS OF INTESTINE

ACUTE TUBULAR NECROSIS OF KIDNEY

NECROSIS OF LIVER

ADULT RESPIRATORY DISTRESS SYNDROME (ARDS)

FEVER

Practice questions

What is the first sign of a shock?

What is the most common type of shock in

ICU?

Syncope

• a transient, self-limited loss of consciousness [with an inability to maintain postural tone that is followed by spontaneous recovery.

• It excludes seizures, coma, shock, or other states of altered consciousness.

• Most causes of syncope are benign • In a small subset - several serious heart

conditions, such as bradycardia, tachycardia or blood flow obstruction (e.g. valvular defect), can also cause syncope

50% of the population may experience

a syncopal event during their lifetime

Syncope (fainting)

rapid drop in blood pressure or heart rate

Prior syncope symptoms

• faintness, dizziness, or light-headedness, vertigo, weakness, diaphoresis, epigastric discomfort, nausea, blurred or faded vision, pallor, or paresthesias

• Red flag symptoms - Exertional onset, chest pain, dyspnea, low back pain, palpitations, headache focal neurologic deficits, diplopia, ataxia, or dysarthria

Treatment

depends on the cause or precipitant of the syncope: • Situational syncope – neurally mediated – vasovagal -

patient education regarding the condition • Orthostatic syncope - Patient education;,

mineralocorticoids, and other drugs (eg, midodrine); elimination of drugs associated with hypotension; intentional oral fluid consumptionadditional therapy in the form of thromboembolic disease (TED) stockings

• Cardiac arrhythmic syncope - Antiarrhythmic drugs or pacemaker placement

• Cardiac mechanical syncope – if valvular disease is present, surgical correction

Hypotension (< 100/60)

Cardiac (Low Output) Vascular origins

Arrhythmias

Structural

Disease

Hypovolemia

Systemic

Vasodilation

Obstructive

• pulmonary

embolism

• bradycardia

• tachycardia

• fibrillation

• valvular disease

• ischemic heart disease

• pericardial disease

• cardiac tamponade

• congenital disease

• obstructive

cardiomyopathy

• dilated cardiomyopathy

• primary pulmonary

• hypertension

• hemorrhage

• diarrhea

• dehydration

• orthostatic

volume shifts

• drugs (diuretics)

• sepsis

• anaphylaxis

• neurogenic

• autonomic dysfunction

• drugs