Lecture 17 - Approach To Infective Fever Flashcards
1
Q
Discomfort due to fever: for each 1degree celcius elevation of body temp
A
- 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
Q
Antipyretic management
A
- 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
Q
Associated symptoms of fever
A
- shaking chills
- ear pain, ear drainage, hearing loss
- visual and eye symptoms
- sore throat
- abdominal symptoms
- back pain, joint, skeletal pain
4
Q
Physical exam for fever
A
- vital signs
- neurological exam
- skin lesion, mucous membrane
- eyes
- ENT
- lymphadenopathy
- lungs/heart
- abdominal region:
- MSK
5
Q
Lab exam
A
- FBC
- EUC
- LFT
- ESR
- CRP
- Urinalysis
- blood, urine
- skin test: TB
- serology
- ANA
6
Q
Imaging
A
- CXR
- ultrasonography
- radiographic contrast study
- radionuclide scan
- CT/MRI
7
Q
Invasive proceduress
A
- Bone marrow
- skin lesion
- lymph node
- liver
- temporal artery
8
Q
Indication for hospitalisation
A
- 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
Q
Causes of Pyrexia of unknown cause (PUO)
A
- infection: half
- neoplasm
- non-infectious inflammatory disease
- miscellaneous cause
- undiagnosed
10
Q
Infections commonly associated with PUO
A
- localized pyogenic infection
- systemic bacterial infection: TB
- fungal infection
- intravascular infection for patients with catheters
- viral infection
- parasitic infection
11
Q
Malignancies commonly associated with PUO
A
- hodgkins disease
- NHL
- Leulkemia
- renal cell carcinoma
- hepatoma
- Colon carcinoma
- Atrial myxoma
12
Q
Non-infectious inflammatory diseases with PUO
A
- collagen vascular/hypersensitivity diseases: lupus, still’s disease, termporal arteritis
- Granulomatous disease: Crohn’s disease, sarcoidosis, idiopathic granulomatous disease
13
Q
Misclellaneous causes of PUO
A
- drug fever
- factictious fever
- Familial mediterranean fever
- recurrent pulmonary emboli
- subacute thyroiditis
14
Q
Drug fever
A
- contamination of the drug with a pyrogen or MO
- pharmacologic action of the drug itself
- allergic reaction to drug
15
Q
Immunocompromised host
A
- 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
Q
Definition of fever in febrile neutropenia
A
- 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
Q
Definition of neutropenic sepsis
A
- 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
Q
DEfinition of neutropenia in febrile neutropenia
A
- Absolute neutrophil count
19
Q
Neutropenia
A
- normal ANC: 2
- neutropenia: ANC
20
Q
When does neutropenia occur
A
- 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
Q
Epidemiology
A
- more than 60% febrile neutropenia episodes are due to infection
- 20% of patients with ANC
22
Q
Duration of neutropenia and risk
A
- 14 days: high risk
23
Q
Common microbes
A
- Gram +: staph aureaus, staph epidermidis, E faecalis, Corynecacterium
- Gram -: e.coli, klebiella, pseudomonas aeruginosa
- Fungi: candia, aspergillus
24
Q
Splenectomy: think what organisms?
A
- 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
