Lecture 17 - Approach To Infective Fever Flashcards Preview

Block 4 - Heamatology > Lecture 17 - Approach To Infective Fever > Flashcards

Flashcards in Lecture 17 - Approach To Infective Fever Deck (43)
1

Discomfort due to fever: for each 1degree celcius elevation of body temp

- metabolic rate increases 10-15%
- insensible water loss increases 300-500ml/m2/day
- o2 consumption icnrased by 13%
- heart rate increases 10-15/min

2

Antipyretic management

- paracetamol usually first line used - well toletared with minimal side effects

- adult: 1000mg q 4h
- can be hepatotoxic in high doses, can upset stomach
- restrict to a maximum of 4g/day

3

Associated symptoms of fever

- shaking chills
- ear pain, ear drainage, hearing loss
- visual and eye symptoms
- sore throat
- abdominal symptoms
- back pain, joint, skeletal pain

4

Physical exam for fever

- vital signs
- neurological exam
- skin lesion, mucous membrane
- eyes
- ENT
- lymphadenopathy
- lungs/heart
- abdominal region:
- MSK

5

Lab exam

- FBC
- EUC
- LFT
- ESR
- CRP
- Urinalysis
- blood, urine
- skin test: TB
- serology
- ANA

6

Imaging

- CXR
- ultrasonography
- radiographic contrast study
- radionuclide scan
- CT/MRI

7

Invasive proceduress

- Bone marrow
- skin lesion
- lymph node
- liver
- temporal artery

8

Indication for hospitalisation

- patients who are clinically unstable or at risk for rapid deterioration
- major alterations of immunity
- need for IV antimicrobials or orhter fludis
- advanced age

9

Causes of Pyrexia of unknown cause (PUO)

- infection: half
- neoplasm
- non-infectious inflammatory disease
- miscellaneous cause
- undiagnosed

10

Infections commonly associated with PUO

- localized pyogenic infection
- systemic bacterial infection: TB
- fungal infection
- intravascular infection for patients with catheters
- viral infection
- parasitic infection

11

Malignancies commonly associated with PUO

- hodgkins disease
- NHL
- Leulkemia
- renal cell carcinoma
- hepatoma
- Colon carcinoma
- Atrial myxoma

12

Non-infectious inflammatory diseases with PUO

- collagen vascular/hypersensitivity diseases: lupus, still's disease, termporal arteritis

- Granulomatous disease: Crohn's disease, sarcoidosis, idiopathic granulomatous disease

13

Misclellaneous causes of PUO

- drug fever
- factictious fever
- Familial mediterranean fever
- recurrent pulmonary emboli
- subacute thyroiditis

14

Drug fever

- contamination of the drug with a pyrogen or MO
- pharmacologic action of the drug itself
- allergic reaction to drug

15

Immunocompromised host

- neutropenia: leukemia therapy, BMT, myelofibrosis, cyclophosphamide, alcoholism -> Staph, E Coli, klebsiella, pseudomonas, enterococci, candida
- T cell suppression: leukemia, lymphoma, transplant, AIDS, steroids, Cyclosporin A -> Herpes, TB, legionella, nocardia, cryptococcus, pneumocystis
- Illness related: CLL, myeloma, splenectomy -> pneumococcus, neisseria, mycoplasma, enterovirus, Giardia

16

Definition of fever in febrile neutropenia

- Single oral temp >38.3
- temperature of >38 on two occsions separated by 1 hour

- if temp is between 37-38, repeat termp in 1 hour to see if the above criteria for treatment are met

17

Definition of neutropenic sepsis

- Hypotension and/or tachycardia in the presence of a neutrophil count less than 1x10^9 and infection
- patients with neutropenic sepsis will not necessarily have a fever
- patients with neutropenic sepsis have a high mortality without prompt appropriate treatment

18

DEfinition of neutropenia in febrile neutropenia

- Absolute neutrophil count

19

Neutropenia

- normal ANC: 2
- neutropenia: ANC

20

When does neutropenia occur

- most chemotherapy agents/protocols cause neutropenia nadir at 10-14 days
- but can see anytime from a few days after chemotherapy to up to 4-6 weeks later depending on agents used

21

Epidemiology

- more than 60% febrile neutropenia episodes are due to infection
- 20% of patients with ANC

22

Duration of neutropenia and risk

- 14 days: high risk

23

Common microbes

- Gram +: staph aureaus, staph epidermidis, E faecalis, Corynecacterium

- Gram -: e.coli, klebiella, pseudomonas aeruginosa

- Fungi: candia, aspergillus

24

Splenectomy: think what organisms?

- strep pneumonia
- neisseria meningitidis
- H. Influenzae

25

Splenectomy/hyposplenism carries an increased risk of overwhelming sepsis

- Sickle cell disease, Coeliac disease
- GvHD
- ITP
- splenic irradiation
- surgical removal

26

Caused of infection after splenectomy

- strep pneumonia

- H.influenza
- Meningococcus
- Salmonella spp
- Dog butes
- Babesia microti
- p. Malaria

27

Preventative measures

- vaccinate before splenectomy with: pneumococcal, meningococcal, H. Influenza
- penicillin prophylaxis
- early empirical therapy
- alert bracelet

28

Examination

- be prepared to find no signs of inflammation

- look in mouth: periodontium, pharynx
- lungs
- abnomen for tenderness - RLQ
- perineum, including anus (no rectal exam)

29

Skin exam

- ask for tenderness
- bone marrow aspiration sites
- vascular catheter access sites
- and tissues around nailes
- rashes

30

Investigations

- FBC
- biochemistry
- microbiology
- radiology

31

Lumbar puncture

- should be considered if a CNS infection is suspected and thrombocytopenia is absent or manageable

32

Skin lesion

- aspiration or biopsy of skin lesion suspected of being infectes should be performed for cytologic testing, gram staining, culture

33

- Imaging

- CXR,
- high resolutoin CT chest only if persistent fevers with pulmonary symptoms after initiation of empiric Abx
- CTA if suspect PE
- CT for abdomen for necrotizing enterocolitis or typhilitis

34

Oral antibiotics

- for patients who are low risk for developing infection-related complications during neutropenia
- oral ciprofloxaxin plus amoxicillin/clavulanate
- oral ciprofloxacin plus clindamycin for penicillin allergy

- this is rare: most patient will receive IV antibiotics

35

- if inpatient and high risk

- empiric antimicrobial therapy after blood cultures
- must be initiated within 1 hour

36

- 3 approached for IV empiric therapy

- IV mono therapy
- IV dual therapy
- combination therapy: mono or dual therapy + vancomycin

37

When temp does not go away

- non-bacterial infection
- bacterial resistance to first line therapy
- slow response to drug in use
- super infection
- inadequate dose
- drug fever
- cell wall deficient bacteria
- infection at an avascular site
- disease-related fever

38

Antifungals

- easy to initiate, difficult to stop
- pulmonary aspergillosis/Sinusitis, Hepatic candidiasis
- CT chest and abdomen
- CT sinuses
- cultures of suspicious skin lesions

39

Antifungals

- voriconazole or amphotericin for high risk option

- fluconazole: only candida
- itraconazole
- echinocandins

40

Infective fevers in transplantation

- Bone marrow or peripheral transplant

- solid organ transplant
- other tissue transplant

41

BM and PBSC transplantation: why does infection occur

- disease itself may be a risk of infection
- patient needs to be immunosuppressed before transplant
- prolonged period of neutropenia
- GvHD
- general support measured complicated by infectin

42

Risk period for infection after transplantation

- neutropenic phase: generally 3 weeks
- 1-3 months: acute immunosuppresion
- 4-12 months: chronic immunosuppression

43

Further infectious complications: days 30-100

- pneumonia: interstitial
- bacterial sepsis with prolonged neutropenia
- fungaemia, dissemination, chronic hepatic candidiasis
- reactivation of latent virus: CMV, BK