Sepsis

Question 1

Sepsis Definition

Answer 1

LIFE-THREATENING ORGAN DYSFUNCTION caused by DYSREGULATED HOST RESPONSE to INFECTION

Question 2

Septic Shock Definition

Answer 2

Identified w/ CLINICAL construct of SEPSIS w/ PERSISTING HYPOTENTION req. VASOPRESSORS to MAINTAIN MAP > 65 mmHg + having SERUM LACTATE > 2mmol/L DESPITE ADEQUATE VOL. RESUSCITATION

Question 3

qSOFA

Answer 3

1. HYPOTENSION = SYSTOLIC < 100 mmHg
   
   2. ALTERED MENTAL STATUS
   3. TACHYPNOEA = RR > 22 per minute

SCORE ≥ 2 criteria suggests GREATER RISK of POOR OUTCOME

Question 4

Presentation (x5)

Answer 4

General:

• FEVER > 38°C = CHILLS, RIGORS, FLUSHES, COLD SWEATS, NIGHT SWEATS etc.
• HYPOTHERMIA < 36°C = esp. in ELDERLY & V. YOUNG CHILDREN (remember IMMUNOSUPPRESSED)
• TACHYCARDIA > 90 bpm
• TACHYPNOEA > 20 per minute
• ALTERED MENTAL STATUS = esp. in ELDERLY
• HYPERGLYCAEMIA > 8 mmol/L in absence of diabetes

Inflammatory Variables:

• LEUCOCYTOSIS (WCC > 12 000/mL)
• LEUCOPENIA (WCC < 4 000/mL)
• NORMAL WCC w/ > 10% IMMATURE FORMS
• HIGH CRP
• HIGH PROCALCITONIN

Haemodynamic Variables:

• ARTERIAL HYPOTENSION (SYSTOLIC < 90 mmHg / MAP < 70 mmHg)
• SvO2 > 70% (O2 sats)

Organ Dysfunction Variables:

• ARTERIAL HYPOXAEMIA (PaO2/FiO2 < 50 mmHg)

• OLIGURIA (< 0.5 mL/kg/h)
• CREATININE INCREASE COMPARED to BASELINE
• COAGULATION ABNORMALITIES (PT > 1.5 or APTT > 60s)
• ILEUS
• THROMBOCYTOPENIA (< 150 000/mL)
• HYPERBILIRUBINAEMIA

Tissue Perfusion Variables:

• HIGH LACTATE
• SKIN MOTTLING + REDUCED CAPILLARY REFILL

Question 5

Management

Answer 5

Sepsis 6:

1. BLOOD CULTURES - microbiological diagnosis + if SPIKE in TEMP., TAKE 2 SETS
2. BLOOD LACTATE LVLS - GENERALISED HYPOPERFUSION/SEVERE SEPSIS/POORER PROGNOSIS
3. MEASURE URINE OUTPUT - RENAL DYSFUNCTION
4. IV ANTIBIOTICS - WORKING DIAGNOSIS from Hx + exam, LOCAL ANTIBIOTIC GUIDELINES; consider allergy, previous MRSA, ESBL, CPE, antibiotic toxicity/interactions
5. IV FLUID CHALLENGE - 30 mL/kg
6. O2 - aim sats. 94 - 98%

Question 6

HDU/ITU Referral

Answer 6

HDU referral if:

• LOW BP RESPONSIVE to FLUIDS
• LACTATE > 2 DESPITE FLUID RESUSCITATION
• ELEVATED CREATININE
• OLIGURIA
• LIVER DYSFUNCTION, BILIRUBIN, PT, PLATELETS (PlT)
• BILATERAL INFILTRATES, HYPOXAEMIA

ITU referral if:

• SEPTIC SHOCK
• MULTI-ORGAN FAILURE
• Req. SEDATION + INTUBATION + VENTILATION

Question 7

What can affect sepsis presentation?

Answer 7

Host: age, co-morbidities, immunosuppression, previous surgery (splenectomy)

Organism: gram +ve, gram -ve, virulence factors, bioburden

Environment: occupation, travel, hospitalisation

Question 8

Pathophysiology

Answer 8

UNCONTROLLED INFLAMMATORY RESPONSE

PT. w/ SEPSIS have FEATURES CONSISTENT w/ IMMUNOSUPPRESSION

* LOSS of DELAYED HYPERSENSITIVITY
* INABILITY to CLEAR INFECTION
* PREDISPOSITION to NOSOCOMIAL INFECTION

CHANGE of SEPSIS SYNDROME OVER TIME

* Initially, INCREASE in IMFLAMMATORY MEDIATORS
* Later, SHIFT TOWARD ANTI-INFLAMMATORY IMMUNOSUPPRESSIVE PHASE
* Depends on health of pt.

Question 9

Pathogenesis (x3)

Answer 9

1. Release of bacterial toxins - bacterial invasion source of dangerous toxins e.g. MAMP (LTA, muramyl dipeptides), superantigens, LPS
2. Release of mediators - effects of infection due to endotoxins + exotoxins, mediator release (pro-inflammatory + compensatory anti-inflammatory)
3. Effects of specific excessive mediators - imbalance bwtn pro-inflammatory & compensatory anti-inflammatory mediators can result in septic shock w/ multi-organ failure + death OR immuno-paralysis w/ uncontrolled infection + multi-organ failure