Date post: | 01-Jun-2015 |
Category: |
Education |
Upload: | bethelhem-berhanu |
View: | 2,473 times |
Download: | 3 times |
SHOCK Part II
Bethelhem Berhanu
Shock
CardiogenicHypovolaemic
Anaphylactic
Distributive
Neurogenic
Classification of Shock
Septic
Hypovolemic Shock
• most common • reduced circulating volume Hemorrhagic shock
Non Hemorragic hypovolemic shock
Vomiting DiuresisDiarrhoea Burns
External or Internal
Pathophysiology of Hypovolemic shock
Hypovolemia
↓Venous Return
Multiorgan failure
Organ dysfunction
Perfusion failure &Tissue hypoxia
Hypotension
↓Cardiac output
↓Preload
BP = CO x TPR
CO = SV x HR
Bodily responses
Physiologic responses- sympathetic activity – tachycardia and SVRHyperventilationcollapse of venous capacitance vesselsstress hormonesAttempt to replace intravascular volume loss
The body will prioritize – Brain and heartSeverity ~ magnitude and the rate of fluid loss
“TENNIS STAGING”15,15-30,30-40,40
American College of Surgeons, 1989
Postural Drop
Clinical Manifestations
• Anxiety - lethargy• Tachypnea• Tachycardia – weak, thready pulse• Normal → Orthostatic drop → Hypotension• Delayed Capillary refill• Cool clammy skin• Oliguria• Thirst
Mild (<20% Blood Volume)
Moderate (20–40% Blood Volume)
Severe (>40% Blood Volume)
Cool extremities
Increased capillary refill time
Diaphoresis
Collapsed veins
Anxiety
Same, plus:
Tachycardia
Tachypnea
Oliguria
Postural changes
Same, plus:
Hemodynamic instability
Marked tachycardia
Hypotension
Mental status deterioration (coma)
Treatment principles: Hypovolemic Shock
• control ongoing loss
• rapid reexpansion of the circulating intravascular blood volume
• GOAL: restore blood volume and improve tissue perfusion and oxygenation
Control bleeding• Direct pressure on the site of wound, Gauze• Elevation• Pressure points -• Tourniquets - • Surgical Methods
• Artery forceps (Spencer Well’s forceps)• Ligation• Cauterisation• Splenectomy – splenic rupture, Hysterectomy for post
partum bleeding
Treatment contd.
• ABC … – Supplemental Oxygen – Endotracheal intubation
• Secure a large bore IV line for fluid resuscitation – Median cubital vein, saphenous vein and
sometimes the internal jugular and subclavian veins
– In pediatric patient - intraosseus line
Re-expansion of Intravascular volume
Fluid TherapyCrystalloid solutions –
0.9% saline Ringer Lactate
Colloid solutions – 5% albumin, gelatins, hetastarch 20 ml/kg in 5 – 15 minutes – repeat upto 60 ml/kg Blood transfusion – 1 unit of blood in 20 minutes
>40% of blood loss (class IV) If the patient is anemic ( Hg < 8g/dl)
We may need to supplement fresh frozen plasma and platelates
Treatment contd.
• Improved perfusion : Warmth Strong pulses Better capillary refill improved mental status Lower HR BP – ideally 90+(agex2) higher Urine output.
Septic Shock
• Septicemia - Presence of microbes or their toxins in blood
• Sepsis – Systemic inflammatory response syndrome (SIRS) that has a proven or suspected microbial etiology
• Severe sepsis – Hypoperfusion with signs of organ dysfunction – Lactic acidosis, oliguria etc.
• Septic shock - Sepsis + hypotension (ABP<90 mmHg systolic, or 40 mmHg less than patient's normal BP) for at least 1 hr despite adequate fluid resuscitation;
Sepsis
Severe Sepsis
Septic shock
MODS
Death
Sepsis and organdysfunction, hypoperfusion,or hypotension
Sepsis-inducedhypotension
Septic, contd.• Importance??
– The most common of the distributive types,– The leading cause of Deaths in ICU in the US. – Increasing in occurrence
• Increased life support for high risk patients• Increase in invasive procedures• Growing number of the immunocompromised
– HIV– Chemotherapy
• PREDISPOSING FACTORS - examples–Extended hospitalization–Advanced age–Debilitating illness–Immunodeficiency disorder–Disseminated malignancy
Septic, contd.
Septic, contd.
• Focus of infection– Pneumonia, UTI, Meningitis, skin and soft tissue
infections, GI infections, etc.
• Gram –ve bacteria (70%) – LPS – Lipid A• Peptidoglycan & lipoteichoic acid of gram +ves• Polysaccharide surface of Candida
Septic, contd.
LPS LBP
LPS
ENDOTHELIAL CELL
Bacteria
LPS
LBP LPS
CD 14
MONOCYTE, MACROPHAGESNEUTROPHILS
soluble CD 14
TNF-AIL-1
Cellular chemotaxisEndotherlial injuryActivation of coagulation cascade
Septic, contd.
• The syndrome of septic shock – Systemic vasodilation (hypotension)– Diminished myocardial contractility– Widespread endothelial injury and activation,
causing systemic leukocyte adhesion and pulmonary alveolar capillary damage (ARDS)
– Activation of the coagulation system, culminating in DIC
Septic Shock Hemodynamics
Warm (hyperdynamic) shock
hypotensive
tachycardia
tachypnea
bounding pulse
warm, well perfused extremities
skin flushed, moist
Cold (hypodynamic) shock
hypotensive
tachycardia
tachypnea
narrow, thready pulse
cold, poorly perfused extremities
skin pale, dry
Principles of treatment:Septic shock
• Ventilatory support• IV fluids – crystalloids or colloids - Fill the tank
• Vasoactive agents – Norepinephrine, Dopamine etc.
• Draw blood for culture – before Antibiotics
• Remove septic focus – Resect a gangrenous bowel, Drain an abscess
• Early empirical antibiotic therapy
Neurogenic Shock
• Cause – high spinal cord injury, spinal anaesthesia
• Pathophysiology - Interruption of sympathetic vasomotor input
• extremities are warm• Rx – IV fluids
• norepinephrine or a pure -adrenergic agent (phenylephrine)
Hypovolemic shock
• History – • Trauma• tearing type of chest pain• hematemesis, melena, severe diarrhea
• P/E – Obvious bleeding• Cool clammy skin• sweating• Narrow pulse pressure• Delayed capillary refill• Anxious, confused
Cardiogenic shock
• History - chest pain, shortness of breath, diaphoresis, syncope etc.
• Symptoms of Hypoperfusion plus • Raised JVP • gallop• Rales – Basal creptations • Beck’s triad
Septic shock
• History – Sx of underlying infection• P/E
– Evidences of Infection – Warm extermities– Bounding pulse– Wide pulse pressure– Brisk capillary refill– Obtunded
References • Harrison’s principles of internal medicine-
18th edition• ACS surgery: principles & practice• Mannipal manual of surgery• Robbin’s basic pathology• Shwartz principles of surgery• Davidson’s principles and practice of medicine• World Wide Web
QUESTIONS?