Infection

Question 1

What type of infections do neutrophils play a role in?

Answer 1

• Bacterial
• Fungal

Question 2

What type of infections do monocytes play a role in?

Answer 2

Fungal

Question 3

What type of infections do eosinophils play a role in?

Answer 3

Parasitic

Question 4

What type of infections do T lymphocytes play a role in?

Answer 4

• Fugal
• Viral
• PJP

Question 5

What type of infections do B lymphocytes play a role in?

Answer 5

Bacterial

Question 6

What supportive factors are aimed at reducing sepsis in haematological malignancy?

Answer 6

• Prophylaxis
• Growth factors e.g. G-CSF
• Stem cell rescue/transplant
• Protective environment e.g. laminar flow rooms
• Intravenous immunoglobulin replacement
• Vaccination

Question 7

What prophylaxis can help reduce sepsis in haematological malignancy?

Answer 7

• Antibiotics (ciprofloxacin)
• Anti-fungal (fluconazole or itraconazole)
• Anti-viral (aciclovir)
• PJP (co-trimoxazole)

Question 8

What is the cause of neutropenia?

Answer 8

Marrow failure proves a higher risk than immune destruction

Question 9

How is the degree of neutropenic risk classified?

Answer 9

Neutrophils

• <0.5x10^9 = significant risk
• <0.2x10^9= high risk

Question 10

What duration of neutropenia carries a high risk?

Answer 10

• Neutropenic >7 days
• In AML therapy and stem cell transplantation there is profound neutropenia ~14-21 days

Question 11

What are additional risk factors for infection?

Answer 11

• Disrupted skin / mucosal surfaces
  
  • Hickman line, venflons
• Altered flora/ antibiotic resistance
  
  • Prophylactic antibiotics
• Lymphopenia
  
  • Disease process e.g. Lymphoma
  • Treatment eg Fludarabine, ATG
  • Stem cell transplantation, GVHD
• Monocytopenia
  
  • Hairy cell leukaemia
  • Chemotherapy

Question 12

What is the pattern of bacterial causes of febrile neutropenia?

Answer 12

• Gram-positive bacteria (60-70%)
• Gram-negative bacilli (30-40%)
• These patterns may now relate to antibiotic prophylaxis, emerging infections, use of lines etc

Question 13

What gram positive bacteria are implicated in febrile neutropenia?

Answer 13

• Staphylococci: MSSA, MRSA, coagulase negative
• Streptococci: viridans
• Enterococcus faecalis/faecium

Question 14

What gram negative bacteria are implicated in febrile neutropenia?

Answer 14

• Escherichia coli
• Klebsiella spp: ESBL
• Pseudomonas aeruginosa
• Enterobacter spp

Question 15

What are possible sites of infection in haematological patients?

Answer 15

• Respiratory tract
• Gastrointestinal (Typhlitis)
• Dental sepsis
• Mouth ulcers
• Skin sores
• Exit site of central venous catheters
• Perianal (avoid PRs!)

Question 16

What type of infection are immunocompromised patients particularly at risk of?

Answer 16

Fungal

Question 17

Give examples of fungal infections.

Answer 17

• Candida
• Aspergillus

Question 18

What can fungal infections in immunocompromised patients lead to?

Answer 18

Life threatening deep seated infection

Question 19

What contributes to the risk of fungal infection?

Answer 19

Monocytopenia and monocyte dysfunction

Question 20

Where are fungal infections likely to affect?

Answer 20

• Lung
• Liver
• Sinuses
• Brain

Question 21

How does neutropenic sepsis present?

Answer 21

• Fever with no localised signs ( single reading of 38.5 or 2 readings of 38, 1 hour apart)
• Rigors
• Chest infection/ pneumonia
• Skin sepsis - cellulitis
• Urinary tract infection
• Septic shock

Question 22

What is the timeline of sepsis?

Answer 22

• Signs of systemic inflammation (SIRS)
• Presumed infection and organ dysfunction
• Severe sepsis/ septic shock

Question 23

What action should be taken for sepsis?

Answer 23

Sepsis 6

Question 24

What are the sepsis 6?

Answer 24

• Administer high flow oxygen
• Take blood cultures, other cultures, consider source control
• Give appropriate IV antibiotics within ONE hour
• Measure serum lactate concentration
• Start IV fluid resuscitation
• Assess/measure urine output

Question 25

What does delay in sepsis treatment lead to?

Answer 25

Every hour’s delay in administering antibiotics increases chance of mortality by 8%

Question 26

How is neutropenic fever investigated?

Answer 26

• History and examination Blood culture: Hickman line & peripheral
• CXR
• Throat swab & other clinical sites of infection
• Sputum if productive
• FBC, renal and liver function, coagulation screen

Question 27

How should neutropenic sepsis be managed?

Answer 27

• ABC resuscitation
• Broad spectrum IV antibiotics (tazocin, gentamicin)
• If a gram positive organism is identified add vancomycin or teicoplanin
• If no response at 72 hours add I.V. antifungal treatment e.g. Caspofungin - empiric therapy
• CT chest/abdo/pelvis to look for source
• Modify treatment based on culture results

Question 28

When may patients be severely lymphopenic?

Answer 28

• Stem cell transplant recipients, especially allogeneic
• Recipients of Total-Body Irradiation (TBI)
• Graft vs Host Disease
• Nucleoside analogues (fludarabine) or ATG
• Lymphoid malignancy e.g Lymphoma, CLL, ALL

Question 29

What infections are severly lymphopenic patients at particular risk of?

Answer 29

• Atypical pneumonia
  
  • Pneumocystis Jirovecii (PJP)
  • CMV
  • RSV
• Viral
  
  • Shingles (Varicella Zoster)
  • Mouth ulcers (Herpes simplex)
  • Adenovirus
  • EBV (PTLD)
• Fungal
  
  • Candida, aspergillus, mucormycosis
• Atypical mycobacteria
  
  • Skin lesions, pulmonary and hepatic involvement