S3 L1 - Sepsis, pneumonia and aspiration pneumonia Flashcards
Sepsis
Sepsis
Sepsis is characterised by a life-threatening organ dysfunction due to a dysregulated host response to infection
Serious injury of the body’s own tissues and organs caused when the inflammatory response to infection becomes systemic and overwhelming
Septic shock
Septic shock is a subset of sepsis where particularly profound circulatory, cellular and metabolic abnormalities substantially increase mortality
When a septic patient becomes shocked (catastrophic fall in BP) causing abnormalities such as ischaemia and lactate production
- *Inflammation:**
- 3 changes that occur with inflammation
- What happens to this inflammation with sepsis
Important caveats with sepsis…
- *3 changes that occur with inflammation:**
- Vasodilation
- Capillary leakage
- Amplication of thr immune system
What happens to this inflammation with sepsis:
Initially the inflammation is local, only in the vicinity of the micro-orgnaisms
Sepsis occurs when this inflammatory process becomes overwhelming and occurs throughout the whole body
- *Important caveats with sepsis…**
- Not all infections will become sepsis. Progression depends on many features including,
- Pathogen eg virility
- Patient eg immunosuppressed, age, co-morbidities (diabetes)
- Systemic inflammatory response is not always caused by infection
- Beware the immunocompromised patient who is not showing any features of inflammation
REMEMBER - STEROIDS ARE IMMUNOSUPPRESSANTS
- *Microscopically what happens in sepsis**
- BP equation
- Two reasons for the drop in BP
- Compensation
Microscopically what happens in sepsis
BP equation:
BP=Stroke Volume(SV)xTotal Peripheral Resistance(TPR)xHeart Rate(HR)
Two reasons for the drop in BP:
Leaky capillaries cause a reduction in circulating volume -> This reduces preload and therefore stroke volume (SV)
Vasodilation causes a reduction in total peripheral resistance (TPR)
lower SV x lower TPR x HR = would cause a drop in blood pressure
Compensation:
However, the heart rate rises to try to compensate and maintain the BP. But if not treated early – patient may decompensate
- *Decompensation**
- What is this
- What does this lead to…
Decompensation
What is this
Decompensation – when diseased system is no longer able to compensate eg when the HR can no longer maintain the BP
What does this lead to…
SEPTIC SHOCK
When the blood pressure falls, there is insufficient delivery of oxygen to the organs
Hypoxia causes tissue ischaemia, anaerobic respiration and impaired organ function
If not treated quickly, hypoxia can cause cell death
- *End Organ Damage
- **4 organs in particular are very vulnerable to lack of oxygen, explain the effect of low oxygen to these organs
Kidneys: Acute Kidney Injury
Liver: Decreased synthesis, eg clotting factors
Heart: Type 2 myocardial infarction
Brain: Drowsiness/Confusion
- *Some observations with a septic patient stated below, state the pathophysiology:**
- HR rises
- RR rises
- Urine output drops
- BP falls
How do we very generally assess how ill a patient is?
- HR rises: Attempting to compensate for decreased TPR and decreased SV
- RR rises: The reasons behind this will be taught next year – it is to try to maintain the blood pH
- Urine output drops: Trying to conserve circulating volume
- BP drops: when HR is no longer able to compensate for decreased TPR and decreased SV
**How do we very generally assess how ill a patient is?** NEWS score (higher the score, the more ill the patient is)
- *How do we diagnose sepsis?**
- Name of system
- What are some of the red flags?
Red Flag Sepsis
Treatment of Sepsis
Sepsis Six - aim to deliver all of this in 1 hour
- *Pneumonia**
- Pathogen
- Patient risk factors
- Mechanism of infection
- Symptoms
- Management
- Outcome
- *Aspiration pneumonia**
- Pathogen
- Patient risk factors
- Mechanism of infection
- Management
- Outcome
