Fever ppt by DR GIRISH JAIN

FEVER PPT BY DR GIRISH JAIN.

1. FEVER DR GIRISH JAIN, JR1 RESPIRATORY MEDICINE DEPARTMENT MAHATMA GANDHI MEDICAL COLLEGE, JAIPUR

2. Most common presenting symptom to clinician. May associated with other symptom eg chills, rigor , bodyache , generalised weakness, headache, anorexia etc

3. Pyrexia –Greek- pyr meaning fire. Febrile- Latin- febris meaning fever.

4. Normal temperature regulation in body Normally heat is continuously produced in body and being lost to surroundings. Rate of heat production= rate of heat loss, person is said to be in heat balance. When there is disturbance of equilibrium between the two, then body temperature may rise-fever, or fall-hypothermia.

5. No single core temperature can be considered normal, there is always a range. Core temperature is normally maintained within a range of 36.0 C-37.5C(97 F-99.5 F).

6. At 6 AM 37.0C(98.6 F) At 6 PM 37.6 C(99.6F)- increased BMR & muscle activity. An a.m. temperature of >37.2°C (>98.9°F) An p.m. temperature of >37.7°C (>99.9°F) defines a fever

7. Normal diurnal variation-1 F -Temperature Rectal>Oral> Axillary

8. Temperature regulation- Preoptic area of anterior hypothalamus Physiological thermostat

9. Factors Determining Rate of Heat Production a. Basal metabolic rate of body b. Muscle activity c. Effect of thyroid hormones d. Effect of epinephrine and norepinephrine .

10. Method of Heat Loss from Body a. Radiation: Loss of heat from body in form of infrared rays. b. Conduction: Heat is conducted from body to objects in contact with it, e.g. chair, bed, etc.

11. c. Convection: Heat is lost from body by air currents surrounding it. d. Evaporation: Evaporation of water (sweat) from body surface serves as an important protective mechanism in reducing body temp .

12. Fever:- Is an elevation of body temperature above normal circadian variation as a result of change in thermoregulatory centre, located in anterior hypothalamus.

13. Relation with Pulse, Resp. , BMI With every 1°F rise of temp >100 F Pulse rate increases 10, Respiratory rate by 4 BMR by 7 Oxygen consumption increases by 13%.

14. Stages of fever 4 successive stages - 1 . Prodrome nonspecific complaints , mild headache, fatigue , general malaise , aches and pains. 2 . Temperature rises generalized shaking with chills and feeling of being cold Vasoconstriction, piloerection precede onset of shivering skin is pale

15. 3. Flush cutaneous vasodilation occurs and skin becomes warm, flushed 4. Defervescence Initiation of sweating.

16. Pathogenesis of fever Pyrogen -Any substance that cause fever Exogenous pyrogens -derived from outside the patient: microbial products, microbial toxins, or whole microorganisms

17. Eg - Lipopolysaccharide ( endotoxin ) of gram-negative bacteria. - Enterotoxins of Staphylococcus aureus They induce host cells, i.e , blood leukocytes, tissue macrophages to produce endogenous pyrogens ( e.g., interleukin-1).

18. Pyrogenic cytokines- include IL-1, IL-4, IL-6, TNF, ciliary neurotropic factor (CNTF), IFN-alpha. Endogenous pyrogens increase set point hypothalamic thermoregulatory center through prostaglandin E2.

19. Mechanisms of fever

20. The effects of fever Metabolic effects: Increased need for oxygen Increases heart rate Increases respiration Increased use of body proteins as an energy source During fever body switches from using glucose (an excellent medium for bacterial growth) to metabolism based on protein and fat breakdown

21. The effects of fever It enhance immune function Increases motility and activity of WBC Stimulates the interferon production and activation of T cells Inhibits growth of some microbial agents: Many microbial agents that cause infection and grow at normal body temperatures.

22. Celcius Fareinheit Hypothermia <35 C <95 F Subnormal 35-36.7 95-97 Normal 36.7-37.2 98-99 Mild Fever 37.2-37.8 99-100 Moderate Fever 37.8-39.4 100-103 High Fever 39.4-40.5 103-105 Hyperpyrexia >40.5 >105

23. Types of fever Continous fever -Temperature remains above normal throughtout the day -Does not fluctuate more than 1 C in 24 hrs. Eg lobar pneumonia, UTI, infective endocarditis , brucellosis

24. Remittent fever Temperature remains above normal throughout the day Fluctuate more than 1 C in 24 hrs. Eg typhoid , viral upper respiratory tract, legionella , and mycoplasma infections

25. Intermittant fever Temperature is present for some hours in a day and remits to normal for remaining time. Daily spike-Quotidian Every alternate day-Tertian Every third day- Quartan Eg malaria , kala-azar , septicemia

26. Hetic /Septic Temperature variation between peak and nadir is more than 5 C. Eg septicemia

27. Pel Ebstein fever Bouts of febrile and afebrile periods Temperature takes 3 days to rise, remains high for 3 days and remits in 3 days, followed by apyrexia for 9 days. Eg Hodgkin lymphoma

28. Low grade fever Temperature present daily, mainly in evening for several days but usually does not exceed 37.8 C. Eg tuberculosis

29. Aseptic fever- Malignancies Acute Myocardial Infacrtion Sarcoidosis , Chronic renal failure Collagen vascular diseases Drug fever Radiation sickness Post surgical patients

30. Drug fever Prolonged fever Relative bradycardia and hypotension Perisist 2-3 days even after drug is withdrawn Eg penicillins,procainamide,propylthoiuracil, sulphonamides,anticonvulsant

31. Fever with Relative Bradycardia 1. Typhoid fever 2. Meningitis 3. Viral fever (Influenza) 4. Brucellosis 5. Leptospirosis 6. Drug induced fever

32. Fever with rigors Malaria Kala azar UTI Septicemia Infective endocarditis Collection of pus in body Lobar pneumonia Cholangitis pyleonephritis

33. Fever with rash 1. Rash appearing on 1st day of fever— Chicken pox. 2. Rash appearing on 4th day of fever— Measles. 3. Rash appearing on 7th day of fever— Typhoid.

34. Fever with membrane in throat Diphtheria Infectious mononucleosis Agranulocytosis

35. Fever with delerium Encephalitis Tyhpoid Meningitis Hepatic encephalopathy

36. Hyperpyrexia When body temperature > 105 F. Cause 1 Pontine haemorhrage 2 Rheumatic fever 3 Menigococcal meningitis 4 Cerebral malaria 5 Septicimia 6 Enchephalitis

37. Pyrexia of unknown origin Persistance of temperature > 101.2 F > 3 weeks duration Faliure to reach diagnosis even after 1 week of evaluation

38. Causes Abcesses - subphrenic /liver/retroperitoneal UTI Endocarditis , hepatobiliary infections, osteomylitis HIV Parasitic infections Malignancy Collagen vascular disease Factitious fever Hyperthyroidism Sarcoidosis

39. Malignancies associated with PUO Hodgkin’s disease NHL Leukaemia Hepatoma Renal cell carcinoma Ca colon

40. Neuroleptic malignant syndrome Characterized by- -Lead pipe muscle rigidity - Extrapyramidal side effects -Autonomic dysregulation -Hyperthermia.

41. Cental D2 receptor blockage - elevated hypothalamic set point. Block of nigrostriatel pathway - muscle rigidity.

42. Cause Succinylcholine Phenothiazines Haloperidol Fluoxetine , loxapine Tricyclic benzodiazepines Metoclopramide , domperidone

43. Management by cold sponging Dantrolene (central muscle relaxent ) Drug of choice- bromocriptene

44. Thank you...