Sepsis profoma Flashcards
What is sepsis?
A life-threatening organ dysfunction secondary to a dysregulated host response to infection
i.e. immune system overreacts to an infection & starts to damage self tissues & organs through systemic inflammation.
What is septic shock?
The subset of sepsis in which underlying circulatory & cellular or metabolic abnormalities are profound enough to increase mortality substantially
- Septic shock involves persistent hypotension. - Can lead to organ failure and death.
What is septicemia?
a bacterial infection that enters the bloodstream.
Sepsis is a complication of septicemia.
Epidemiology for sepsis
YEPI – young, elderly,pregnant,immunodeficient.
Pathophysiology of sepsis
Caused by systemic inflammation
Immune system activation:
- innate immune system is activated by antigens binding to host’s toll-like receptors on APCs e.g. leukocytes & macrophages.
- Activation of the innate immune system leads to:
1. Pro-inflammatory cytokines e.g. TNF-α, IL-1 & IL-6 are released. These activate immune cells
2. ROS, nitric oxide (NO) & proteases are released, causing bacterial killing. NO is responsible for vasodilation and has been implicated in sepsis-induced mitochondrial dysfunction
3. The complement system is activated - this mediates activation of leukocytes so they can:
- Directly attack the organism (phagocytes, cytotoxic T cells).
- Identify the pathogen for attack by others (antigen presenting cells, B lymphocytes).
- Remember it for future infection (memory cells, B lymphocytes.
- Increased production & chemotaxis of T helper cells
Endothelium & coagulation system:
- Activated endothelium allows:
1. Adhesion & migration of stimulated immune cells.
2. Becomes porous to large molecules such as proteins, resulting in tissue oedema
- There is an increase in pro-coagulant factors & reduced circulating levels of natural anticoagulants
- This leads to microthrombi forming.
Pathophysiology of septic shock
Inflammation & organ dysfunction:
- Vasodilation & increased capillary permeability - leading to a reduction in circulating volume.
- Hypovolaemia & reduced left ventricle contracting = hypotension.
- Heart rate increases to compensate but this becomes exhausted = hypoperfusion & shock.
- Organs may become hypoxic because:
- Impaired tissue oxygen delivery is exacerbated by pericapillary oedema
- These abnormalities may lead to lactic acidosis, cellular dysfunction, & multi-organ failure.
Warning signs of sepsis in adults
Difficult to spot sepsis - symptoms can be similar to flu, gastroenteritis or a chest infection.
Altered metal state -e.g. slurred speech or confusion.
Fever or hypothermia - NEVER rule out sepsis on the basis of a normal temp.
Tachycardic - racing heart (more than 90 bpm) NOTE: In pregnancy, heart rate is usually 10-15 bpm faster. And older people can present with arrthymias rather than tachycardia.
Tachypnoeic - breathless (more than 20 breathes per min)
Low oxygen saturation** - if you are unable to measure it, think septic shock.
Low urine output - suggests intravascular volume depletion and/or acute kidney injury.
Poor capillary refill, mottling & ashen skin - signs of circulatory insufficiency.
Cyanosis - blue skin or lips.
Nausea, vomiting, diarrhoea
Warning signs in children
Fever - more than 38°C
Hypothermic- less than 36°C
Tachyponea - fast breathing
Tachycardia - fast heart rate
Altered mental state e.g. drowsiness, delirium, lethargy, floppiness.
Decreased peripheral perfusion (cold shock) - cold peripheries, prolonged capillary refill, weak pulses.
Decreased urine output
Mottling of skin, ashen appearance, cyanosis- signs of circulatory insufficiency.
Warning signs in infants
Apnoea, grunting & nasal flaring - temporary cessation of breathing.
Bradycardia - heart rate is lower than the 10th percentile for their age.
Altered mental state e.g. irritability, non-responsiveness to social queues, poor handling.
Weak high-pitched or continuous cry.
Change in activities & feeding - not feeding.
Temperature instability
Dry nappies- decreased urine output.
Investigations for sepsis
Blood tests- take immediately before antibiotics:
- blood culture
- full blood count– thrombocytopenia. High WBC count but this is not accurate and should instead focus on organs not working.
- U&E (inc. creatinine) - looks for renal dysfunction
- LFTs
- Clotting screen - prothrombin time, partial thromboplastin time & fibrinogen.
- CRP- high but not specific to sepsis.
Urine output
- Measure hourly
- Anyone who has not passed urine for the past 12-18 hours is severely at risk of sepsis.
ECG
- Rule out differential diagnoses e.g. myocardial infarction
- Detect arrhythmias- commonly seen in old people instead of tachycardia.
Blood gas:
-Arterial CO₂
- Serum lactate - persistent levels >2 mmol/L is bad- Suggests muscle degeneration.
- Determines the severity of sepsis.
- Marker of stress
- Highlights the possibility of hypoperfusion.
- Can be normal - consider patient’s NEWS score too.
- Serum glucose - may be elevated, w/ or w/out diabetes, due to stress response.
Other tests- focus on identifying pathogen that caused sepsis
- urine analysis
- chest x-ray
- HIV screen
- cultures from joint fluid & urine
- echocardiogram (ultrasound of heart)
Management for sepsis
Sepsis 6 + 2:
Give 3:
- high- flow oxygen
- give fluid challenge
- give IV antibiotics - w/in 1 hour of sepsis or septic shock recognition. Do not wait for blood culture results.
Take 3:
- take appropriate cultures- before antibiotics are started
- measure lactate
- measure urine output
Consider 2:
- assess fetal state & consider delivery or evacuation of retained products of conception
- Consider thrombo-prohylaxis
Failure to respond within hour = critical care.
- Systolic blood pressure persistently below 90 mmHg.
- Reduced level of consciousness despite resuscitation.
- Respiratory rate over 25breaths per minute or a new need for mechanical ventilation.
- Lactate not reduced by more than 20% of initial value within 1hour.
Prognosis of sepsis
- sepsis leads to death
- Sepsis survivors suffer w/ additional morbidities e.g. higher risk of readmissions, CVD, cognitive impairment & death
- ~60% of sepsis survivors have at least onerehospitalisation
- 1 in 6 have severe persistent impairments e.g. inability to bathe/dress alone, cognitive impairment, depression, PTSD.
