Sepsis

Question 1

What is sepsis?

Answer 1

A condition where the body launches a large immune response to an infection that causes systemic inflammation and affects the functioning of the organs of the body

Question 2

Pathophysiology of sepsis

Answer 2

Bacteria/pathogens recognised by macrophages, lymphocytes and mast cells

Cells release cytokines (interleukins, TNF) which activate other parts of immune system

Immune activation leads to further release of chemicals e.g. NO causing vasodilation

Cytokines cause endothelial lining to become permeable - fluid leaks into extracellular space -> oedema

Activation of coagulation system -> thrombocytopenia, haemorrhages, inability to form clots -> DIC

Lactate rises due to hypoperfusion -> starves tissues of oxygen so they switch to anaerobic respiration -> waste product of this is lactate

Question 3

What is “septic shock”?

Answer 3

Systolic blood pressure less than 90 despite fluid resuscitation

Hyperlactaemia (lactate > 4 mmol/L)

Question 4

What constitutes severe sepsis?

Answer 4

When sepsis is present and results in organ dysfunction:

Hypoxia

Oliguria

AKI

Thrombocytopenia

Coagulation dysfunction

Hypotension

Hyperlactaemia (> 2 mmol/L)

Question 5

Risk factors for sepsis

Answer 5

Very young or old patients (under 1 or over 75 years)

Chronic conditions such as COPD and diabetes

Chemotherapy, immunosuppressants or steroids

Surgery or recent trauma or burns

Pregnancy or peripartum

Indwelling medical devices such as catheters or central lines

Question 6

Signs of sepsis

Answer 6

Signs of potential sources such as cellulitis, discharge from a wound, cough or dysuria

Non-blanching rash can indicate meningococcal septicaemia

Reduced urine output

Mottled skin

Cyanosis

Arrhythmias such as new onset atrial fibrillation

Question 7

Investigations in sepsis

Answer 7

FBC (to assess cell count including white cells and neutrophils)

U&Es( to assess kidney function and for AKI)

LFTs (to assess liver function and for possible source of infection)

CRP (to assess inflammation)

Clotting (to assess for DIC)

Blood cultures (to assess for bacteraemia)

Blood gas (to assess lactate, pH and glucose)

Question 8

Investigations to locate source of infection in sepsis

Answer 8

Urine dipstick and culture

CXR

CT scan if intra-abdominal infection or abscess suspected

LP for meningitis or encephalitis

Question 9

Sepsis Six

Answer 9

Three tests:
Blood lactate
Blood cultures
Urine output

Three treatments:
Oxygen to maintain sats 94-98%
Empirical broad spectrum antibiotics
IV fluids

Question 10

What is neutropenic sepsis?

Answer 10

Medical emergency

Sepsis in a patient with a low neutrophil count of less than 1 x 109/L

Question 11

Which medications can cause neutropenia?

Answer 11

Usually anti-cancer or immunosuppressant treatment

Anti-cancer chemotherapy

Clozapine (schizophrenia)

Hydroxychloroquine (rheumatoid arthritis)

Methotrexate (rheumatoid arthritis)

Sulfasalazine (rheumatoid arthritis)

Carbimazole (hyperthyroidism)

Quinine (malaria)

Infliximab (monoclonal antibody use for immunosuppression)

Rituximab (monoclonal antibody use for immunosuppression)

Question 12

Treatment of neutropenic sepsis

Answer 12

Immediate broad spectrum antibiotics e.g. piperacillin with tazobactam (tazocin)