fever.ppt presentation in simple words easy to understand

Fever ppt

1. Capt Ankur APPROACH TO FEVER AND PUO Moderator: Lt Col Avinash Mishra Cl Spl (Med), 187 MH

2. OUTLINE Definitions Pathophysiology of fever Types of fever Causes of fever Approach to a case of fever Serological diagnosis of typhoid PUO- Definitions and approach Factitious fever Drug fever

3. DEFINITION Fever is defined as an a.m. temperature >37.2°C (>98.9°F) or p.m. temperature >37.7°C (>99.9°F) Based on normal circadian variation of temperature which is 0.5°C (>0.9°F) In patients recovering from febrile illness this daily variation can be as much as 1.0°F Harrison’s Principles of Internal Medicine, 20 th edn

4. Fever Fever is an elevation of body temperature that exceeds the normal daily variation and occurs in conjunction with an increase in the hypothalamic set point (e.g., from 37°C to 39°C). Once the hypothalamic set point is raised, mechanisms to raise body temperature to reach that level come into action Harrison’s Principles of Internal Medicine, 20 th edn

5. FEVER Fever is a tightly controlled elevation in body temperature above the normal range in response to a central nervous system change in the set point Goldman’s Cecil Medicine, 24 th edn

6. FEVER Fever is an elevation in temperature - usually a sign of an infectious or inflammatory condition, although it may also result from thyrotoxicosis , heat stroke, neoplasia , drugs, and many other entities Sapira’s Art and Science of bedside diagnosis, 4 th edn

7. Pathophysiology

8. TYPES OF FEVER

9. Continuous fever Temperature remains above baseline through out the day and fluctuates not more than 1 ° F in 24h. eg. Lobar pneumonia, IE, enteric fever

10. Remittent fever Temperature remains above baseline throughout the day but fluctuates more than 1 ° F in 24h

11. Intermittent fever Temperature elevation is present only for certain periods, cycles back to normal Quotidian- Periodicity of 24h eg. P falciparum Tertian- Periodicity of 48h eg. P vivax / ovale Quartan- Periodicity of 72h eg. P malariae

12. Pel Ebstein fever: Fever lasting for 3-10days followed by afebrile period of 3-10days. Eg. Hodgkins lymphoma Cyclic neutropenia : fever every 21 days Step ladder pattern: Enteric fever

13. Causes Infectious Malignancy Autoimmune Miscellaneous

14. HISTORY TAKING Fever Onset Duration Intensity Periodicity Chills/ rigors Rash Convalescence Associated symptoms

15. Associated symptoms Respiratory- sore throat, cough, sinus pain, wheeze, dyspnea (eg. Sinusitis, pneumonia, acute bronchitis) Genitourinary- dysuria, loin pain, discharge PV/PU (eg. UTI, PID) Abdomen- diarrhea, pain abdomen, wt loss (eg. AGE, food poisoning) CNS- headache, altered sensorium, focal deficit (eg. Meningitis, encephalitis, cerebral malaria) Musculoskeletal- joint pain, swelling/ effusion (eg. Osteomyelitis, infective arthritis, reactive arthritis) Skin rash

16. Personal and social history Animals/ birds in the house Unpasteurized milk Sexual and other high risk behavior Family history Tb, leprosy, recent h/o cholera, typhoid Travel history Based on IP; 1-10d- Malaria, dengue, salmonella 10-21d- Typhoid, brucella, hep A Wks- months- HIV, Amoebiasis

17. APPROACH TO A CASE WITH FEVER

18. Examination Rule out sepsis RED FLAGS Altered mental state Headache/ stiff neck Petechiae/ purpura Immunosuppressant Co morbidities: Cancer, HIV, organ transplant recipient

19. Identify the focus of infection, if any Relevant investigations and treatment Acutely ill febrile patient (Assess ABC) Rule out sepsis (qSOFA > 2/3) Treatment guidelines for antimicrobial use in clinical syndromes, ICMR 2017 Assess the clinical syndrome Consider risk factors, geography and season and associated symptoms

20. FEVER with Rash/ thrombocytopenia (Rubella, chicken pox, scrub typhus) 2. Neutropenia (MDS, cancer chemotherapy, post HSCT) 3. Jaundice (Leptospira, malarial hepatopathy , brucella) 4. ARDS (Aspiration pneumonia, necrotizing pancreatitis, burns with secondary sepsis) Encephalopathy (Bacterial meningitis, viral meningoencephalitis , cerebral malaria) 7. MODS/ Sepsis (Severe systemic infection- pneumonia, urosepsis ) 8. Acute Undifferentiated Fever Treatment guidelines for antimicrobial use in clinical syndromes, ICMR 2017

21. INVESTIGATIONS CBC PBS for e/o sepsis ESR, CRP (when suspecting occult infection) LFT RFT with electrolytes Urinalysis CXR RDTs at admission (i) Malaria card test (kit must use HRP/LDH) Malaria is ruled out with two negative RDTs (ii) Dengue for NS1 Ag, IgM, IgG {NS1 Ag Day 1 – 5 of illness} (iii) Typhidot IgM, IgG {Sensitivity 95- 97%} (iv) H1N1 PCR Treatment guidelines for antimicrobial use in clinical syndromes, ICMR 2017

22. Treatment guidelines for antimicrobial use in clinical syndromes, ICMR 2017 Rapid test suggest diagnosis MALARIA Inj Artesunate 2.4mg/kg at admission, 12h, 24h, then OD for 5 days DENGUE Supportive care for bleeding and electrolyte abnormalities Other drugs ?? TYPHOID Inj Ceftriaxone 100mg/kg/d

23. Other drugs ?? RDTs suggest Malaria

24. Treatment guidelines for antimicrobial use in clinical syndromes, ICMR 2017

25. Serological diagnosis of typhoid WIDAL Typhidot IgM, IgG Gold standard : Laboratory confirmed culture positivity followed by microbiological identification API Recommendations for the Management of Typhoid Fever, JAPI, Nov 2015

26. WIDAL Not recommended before one week, might be falsely positive Single WIDAL no value Demonstrate rise in Ab titers ( 4 fold rise ) over 10- 14 days Usually O - Ab take 6- 8 days to appear and H - Ab 10- 12 days after disease onset Presumptive diagnosis may be considered if anti – O >1:80 and anti – H > 1:160 (Difficult to have a definite cutoff since it varies between areas and between times in given areas) Limited sensitivity (57%) and specificity (83%) especially in endemic areas (1) (1) Sherwal et al, A comparative study of Typhidot and Widal in patients with typhoid: JIACM 2004; 2 API Recommendations for the Management of Typhoid Fever, JAPI, Nov 2015

27. ADVANTAGES Inexpensive Good for screening in large patient population in endemic regions despite mixed results DISADVANTAGES Limited sensitivity and specificity Sensitivity: 47- 77% Specificity: 50- 92% (1) Prior antimicrobial treatment may affect antibody response Over diagnosis if relied upon solely especially in endemic areas False positive results: Malaria, bacteremia , typhus, cirrhosis May be negative in 30% of culture proven cases of enteric fever (1) API Recommendations for the Management of Typhoid Fever, JAPI, Nov 2015

28. Typhidot IgM, IgG Rapid dot Enzyme Immunoassay Based on antibodies against Outer Membrane Protein (OMP) Becomes positive right in the first week Sensitivity 95%, specificity 75% API Recommendations for the Management of Typhoid Fever, JAPI, Nov 2015

29. ADVANTAGES Simple, rapid High sensitivity and specificity IgM is more sensitive than culture (93%) High NPV, PPV High NPV makes it suitable for use in areas of high endemicity Can be used even in the first week of fever DISADVANTAGES IgG can persist for > 2years after typhoid infection, hence IgG alone cannot differentiate acute and convalescent cases False positives: previous infection API Recommendations for the Management of Typhoid Fever, JAPI, Nov 2015

30. Rx DOC- Paracetamol Aspirin and other NSAIDS must be specially avoided Risk of GI Bleed and anti platelet action Reye’s syndrome in pediatric population If oral acceptance is poor, consider parenteral NSAIDS/ rectal suppositories

31. FUO An illness of >3 weeks’ duration with Fever of ≥38.3°C (≥101°F) on two occasions and An uncertain diagnosis despite 1 week of inpatient evaluation Petersdorf and Beeson, 1961

32. FUO FUO is defined as 1. Fever ≥38.3°C (≥101°F) on at least two occasions 2. Illness duration ≥3 weeks 3. No known immunocompromised state 4. Diagnosis remains uncertain after thorough history-taking, physical examination, and obligatory investigations Harrison’s Principles of Internal Medicine, 20 th edn

33. Obligatory investigations CBC with ESR, CRP RFT with electrolytes (Electrolytes, creatinine) LFT with enzymes (Total protein, ALP, ALT, AST) Urinalysis and urine culture Blood cultures ( n = 3) Chest x-ray USG Abdomen S. LDH, CK S. Ferritin ANA, Rheumatoid factor, SPEP/ UPEP Tuberculin skin test (TST) or interferon γ release assay (IGRA) Harrison’s Principles of Internal Medicine, 20 th edn

34. Causes of FUO

35. APPROACH TO FUO

36. apiindia.org/medicine_update_2013/chap11.pdf

37. apiindia.org/medicine_update_2013/chap11.pdf

38. apiindia.org/medicine_update_2013/chap11.pdf

39. Approach to FUO

40. Hyperpyrexia Fever > 41.5°C (>106.7°F) Seen in Severe infections and CNS hemorrhages Fever due to infectious diseases rarely exceed 106°F This natural “thermal ceiling” is mediated by neuropeptides functioning as central antipyretics

41. Hyperthermia (Heat stroke) Uncontrolled increase in body temperature (T >104 . F) that exceeds the body’s ability to lose heat The setting of the hypothalamic thermoregulatory center is UNCHANGED Types Classical : Involves passive exposure to high environmental heat Exertional: Following strenuous exercise/ work in hot/ humid environment

42. Fever vs Hyperthermia(Heat stroke) Differentiation is critical as hyperthermia can be rapidly fatal and does not respond to antipyretics Dx H/o events preceding rise in temperature Exposure to high environmental heat/ strenuous exercise Intake of drugs that interfere with thermoregulation Skin Fever- Usually cold due to vasoconstriction and shunting (Heat conservation mechanisms) Hyperthermia- Hot and DRY (Due to failure of heat losing mechanisms) Response to usual doses of antipyretics Fever/ hyperpyrexia- Resolution/ reduction in temperature Hyperthermia- No response to antipyretics

43. FACTITIOUS FEVER Fever eng i nee r ed b y th e p a tien t b y manipulating the thermometer and/or temperature chart apparently to obtain medical care Uncommon and typically presents in young women with a medical and nursing background Eg. dipping of thermometers into hot drinks to fake fever This factitious disorder is usually medical but may relate to a psychiatric illness with reports of depressive illness

44. Clues to Dx Patient looks well Absence of temperature-related changes in pulse rate Temp > 41°C Absence of sweating during the period of fever Normal ESR, CRP Useful methods for the detection of factitious fever include Supervised/ observed temperature recording Measuring the temperature of freshly voided urine FACTITIOUS FEVER

45. DRUG FEVER Febrile reaction induced by a drug without additional clinical features like skin eruption Febrile response temporally coincides with drug administration Disappearance of fever after discontinuation of the suspected drug is the cornerstone of diagnosis Other clues- eosinophilia, transaminitis Before stopping the offending/ suspected drug, risk- benefit ratio should be assessed Drugs: Antimicrobials, anticholinergics, anticonvulsants

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