Surgery 2.1 (6-9) - Sheet1 Flashcards
Question
Answer
In the event of a vasodilatory shock, the immune cells elaborate soluble mediators that do what THREE three things to eradicate the pathogens?
Enhance macrophage and PMN killing effector
mechanism, increase procoagulant activity, increase fibroblast activity to localize invaders and increase microvascular blood flow to enhance delivery of killing forces
Define “PMN killing effector”
A polymorphonuclear
Vasodilatory shock is a syndrome initiated by what?
The host’s innate immune response
What stages occur from severe infection to
septic shock?
Systemic inflammatory response syndrome to sepsis to severe sepsis to septic shock.
If left untreated, what can septic shock lead to?
Multiple organ dysfunction syndrome or even death
What are the mortality rates for sepsis?
16-20%
What are the mortality rates for septic shock?
20-50%
What causes are for such a large variation in the mortality rates for septic shock?
The type of infectious organism, the underlying illness or
complication, the timing and the kind of antimicrobial therapy
and degree of system failure present
What is an infection that is widespread throughout the bloodstream called?
Sepsis (or septicemia)
What can sepsis lead to?
Severe symptoms and a life threatening conditions called “septic
shock”
How does sepsis occur?
Sepsis occurs when pathogenic microorganisms cross host
barriers and overwhelm defenses
Name four gram negative bacteria key pathogens
E. Coli, K. Pneumonia, P.
Aeruginosa and N. meningitides
What kind of Gram positive organisms have been noted as causative
agents for sepsis?
S. aeurus, coagulas- negative staphylococcus, S. Pneumonia, Strept. Pyogenes, Enterococcus Rickettsia, viruses, fungi, and
polymicrobial sepsis
What are the most likely causes of sepsis in neonates?
Group B strept., E.coli bearing a pathogenic K1 capsule, Klebsiella sp. and Enterobactes sp
What are some symptoms patients experience as sepsis turns to severe sepsis?
Organ dysfunction, hypoperfusion and hypotension
What are some examples of the “perfusion abnormalities” observed as the disease progresses to sever sepsis?
Confusion or altered mental status, elevated plasma lactate
lvls and oliguria (decrease urine output <30cc)
Define sepsis
A systemic inflammatory response to infection
Define severe sepsis
Sepsis with one or more dysfunctional
organ system
Define Systemic Inflammatory Response Syndrome (or SIRS)
A syndrome in which inflammatory mediators are released secondary to an infectious and/or traumatic insult
Patients will present with TWO of these four conditions if afflicted by Systemic Inflammatory Response Syndrome
- Body temperature can increase above 38oC or drop below 36oC -Tachycardia (>90 bpm) - Tachypnea (>20 Breaths/min) - WBC >12k or <4k
Define Compensatory Anti-inflammatory Response Syndrome
or CARS
A syndrome in which anti-inflammatory mediators
release overcompensates for the systemic inflammatory
response to an infection and/or traumatic insult leading to a
state of immune suppression
Define severe sepsis
Sepsis-associated with lactic acidosis,
oliguria and acute alteration of mental status
What conditions may be present in a case of “moderate sepsis”?
- body temperature >38oC or <36oC
- HR >90
- RR >20 or PCO2 <32
- WBC >12k
- Urine output: 1cc/1kg/hr
Define septic shock
Sepsis-induced hypotension despite
adequate fluid resuscitation with multiple organ dysfunction
(MODS). Hypotension and hyperperfusion secondary to
pathophysiological alteration.
How can you diagnose sepsis?
Evidence of infection and systemic signs of inflammation
How can you diagnose severe sepsis?
Hypoperfusion with signs of organ dysfunction
How can you diagnose septic shock?
Significant evidence of hypoperfusion and systemic
hypotension
What are the immediate things you are doing to spot vasodilatory shock in a patient?
- Aggressive search for infection
- Inspection of all wounds
- Evaluation of all intravascular catheter or other foreign body
- Obtaining appropriate culture
- Adjunctive imaging studies
What are the eight diagnostic assessments for vasodilatory shock?
- Complele blood count and differential
- Coagulation status
- Serum electrolyte level renal and hepatic
function - Arterial blood gas analysis
- Elevated serum lactate level
- Urinalysis and culturing
- Gram staining
- Blood culture
How does vasodilatory shock manisfestate?
Enhanced cardiac output, peripheral vasodilation, fever, Leukocytosis, Hyperglycemia, Tachycardia, confusion, malaise, oliguria, or hypotension
How can you treat vasodilatory shock?
Fluid resuscitation and restoration of circulatory blood
volume with balanced salt solutions, empiric antibiotics, surgical drainage, Vasopressors (like catecholamines, arginine vasopressin) and intensive insulin therapy
What are “empiric antibiotics”?
Typically broad-spectrum antibiotics, in that they treat both a multitude of either Gram-positive and/or Gram-negative bacteria
What is “immune modulation”?
Modulating your own immune response
List the 8 expensive types of immune modulation you’ve been taught
- Anti-endotoxin antibodies
- Anti-cytokine antibodies
- Cytokine receptor antagonist
- Immune enhancers
- Non-isoform specific nitric oxide synthase
inhibitor - Oxygen radical scavenger
- Activated protein C (promotes fibrinolysis and
inhibits thrombosis and inflammation) - Corticosteroids (still controversial)
Why is the form of immune modulation known as “corticosteroids” still controversial?
The role of corticosteroid therapy remains controversial - specifically whether corticosteroids actually reduce mortality. Despite recent meta-analyses, no clear guidance exists on corticosteroid indications and which patients truly benefit
What four things need to be completed within three hours to ensure a patient survives sepsis campaign bundles?
Measure lactate level; obtain blood cultures prior to administration of antibiotics, administer broad spectrum antibiotics and administer 30mL/kg crystalloid for hypotension or lactate less than 4 mmol/L
What three things need to be completed within six hours to ensure a patient survives sepsis campaign bundles?
Apply vasopressers to maintain a mean arterial pressure (MAP equal to or more than 65 mm Hg; in the event of persistant arterial hypotension despite volume resuscitation ensure you measure central venous pressure and measure central venous oxygen saturation; and remeasure lactate if initial lactate was elevated
What is considered elevated levels of lactate during sepsis
CVP or more than or equal to 8mm HG and SCVO of more than or equal to 70 per cent and normalisation of lactate
During neurogenic shock, why does tissue perfusion diminish?
This is the result of loss of vasomotor
tone to peripheral arterial beds.
During neurogenic shock, does vascular capacitance increase or decrease?
Increase
During neurogenic shock, does venous return increase or decrease?
Decrease
During neurogenic shock, does cardiac output increase or decrease?
Decrease cardiac output
What impact is there to the spinal cord during neurogenic shock?
Usually secondary to spinal cord injury from vertebral body
fracture of the cervical or high thoracic region
What happens to sympathetic regulation during neurogenic shock?
Disruption of sympathetic regulation of peripheral vascular
tone
What is “mulitple secondary injury mechanism”?
Vascular compromise to the spinal cord with loss of
autoregulation, vasospasm, and thrombosis
What are the impacts of multiple secondary injury mechanism?
Loss of cellular membrane integrity and impaired energy
metabolism
What happens to free radicals during multiple secondary injury mechanism?
They are released
What are the three spinal causes of neurogenic shock?
Spinal cord trauma, spinal cord neoplasm and spinal/epidural anesthetic
What are the eight manisfestation of neurogenic shock?
- Bradycardia
- Hypotension
- Cardiac dysrhythmia
- Reduced cardiac output
- Decreased peripheral vascular resistance
- Warm extremities
- Motor and sensory deficit
- Radiographic evidence of vertebral fracture.
What is “bradycardia”?
Abnormally slow heart action
What is the collequial term for “hypotension”?
Low blood pressure
How can you treat neurogenic shock?
- Restoration of intravascular volume
- Vasoconstrictors
- Phenylephrine
- Operative attempt to stabilized vertebral fracture and dopamine
What is “Phenylephrine”?
A selective α1-adrenergic receptor agonist of the phenethylamine class used primarily as a decongestant
What is the most common cause of “obstructive shock”?
The presence of tension pneumothorax (the progressive build up of air within the chest’s pleural space)
What is “cardiac tamponade”?
The pressure on the heart that occurs when blood or fluid builds up in the space between the heart muscle and the outer covering sac of the heart
What is a “pulmonary embolism”?
A sudden blockage in a lung artery
“IVC” is an underrecognized entity of thrombosis presentations. What does it stand for?
The Inferior Vena Cava
What is main cause of “pneumothorax”?
A penetrating wound in the thoracic cavity
What can be a common cause of “spontaneous pneumothorax”?
The patient may be a smoker with TB
What are the five classic ways to diagnose obstructive shock during a clinical presentation?
- Respiratory distress
- Hypotension
- Diminished breath sounds
- Hyperresonance to percussion
- Jugular vein distention
What is “jugular vein distention”?
When the jugular vein is visible, it’s known as jugular vein distention
What is hyperresonance to percussion?
Hyperresonance on percussion indicates too much air is present within the lung tissue
When conduction and x-ray to diagnose obstructive shock, what are you looking for?
A shift of mediastinal structures to unaffected side
with tracheal deviation.
What are the “mediastinal structures”?
The trachea; the esophagus; the “great vessels” like the arch of the aorta; thoracic portions of the left common carotid and the left subclavian arteries; Veins like the innominate veins and the upper half of the superior vena cava; the thymus; phrenic and vagus nerves and left recurrent nerves; and the thoracic duct. Some lymph glands can be classifed as “mediastinal structures” too.
How can you treat obstructive shock?
Pleural space decompression with large caliber needle
What kind of tube insertion can be used to treat obstructive shock?
Thoracotomy tube insertion (closed system) at 4th ICS AAL
Definine “cardiac tamponade”
The accumulation of fluid in the pericardial sac to
obstruct blood flow to the ventricles
What are the four main causes of cardiac tamponade?
- Penetration trauma
- Blunt cardiac rupture (this is rare)
- Heart failure
- Uremia
What are some common symptoms of “cardiac tamponade”?
Dyspnea, orthopnea, cough, peripheral
edema, chest pain, tachycardia, muffled
heart tones, jugular venous distention and
elevated CVP
What is “CVP”?
A measure of blood volume and venous return
How can you diagnose cardiac tamponade?
An echocardiography and a two dimensional or trans-esophageal echocardiography (known as a 2D echo)
Define “shock”
Shock is defined as inadequate perfusion to maintain normal
organ function
What is the goal when treating shock?
The restoration of adequate organ perfusion and tissue oxygen
When is resuscitation complete?
When oxygen debt is repaid, tissue acidosis is corrected and aerobic metabolism is restored
What is “etiology”?
The cause, set of causes, or manner of causation of a disease or condition
What are the most common types of shock in a surgical setting?
Hemorrhagic shock, septic shock and traumatic shock
Why is the fast and efficient use of resusication so important?
Expedient operative resuscitation is mandatory to limit the
magnitude of activation of multiple mediator systems and to
abort the microcirculatory changes which may evolve
insidiously into the cascade that ends in irreversible
hemorrhagic shock
What is “compensated shock”?
Compensated shock exists when inadequate tissue perfusion
persists despite normalization of blood pressure and heart
rate
What is “occult hypoperfusion”?
Hypoperfusion in the presence of normal vital signs
Why is occult hypoperfusion worrying in an ICU setting?
It can lead to a significant increase in infection rate mortality in
major trauma patients
What are the “global” endpoints for resuscitation?
Vital signs cardiac output, pulmonary artery wedge pressure oxygen delivery and consumption lactate and base deficit
What are three ways you can treat resuscitation?
Emergency surgical exploration, rapid decompression of pericardium and explore and repair the injury
Define “traumatic shock”
A systemic response after trauma
How can “traumatic shock” be magnified?
A pro-inflammatory response
How many times more likely do patients failing to reverse their lactic acidosis within 12
hours of admission develop an infection compared to those who are normalized?
At least three times more
What happens if prolonged shock is not treated?
Anaerobic metabolic tissue acidosis and
oxygen debt accumulate
What is “hypovolemic shock”?
Hypovolemic shock - also known as hemorrhagic shock - is a life-threatening condition that results when you lose more than 20 percent of your body’s blood or fluid supply.
What is the “pericardium”?
The membrane enclosing the heart, consisting of an outer fibrous layer and an inner double layer of serous membrane.
Define “oxygen debt”
A temporary oxygen shortage in the body tissues
