Fever for 3rd year.

A medical lecture on fever for 3rd year students of Sulaimaneyah university college of medicine.

1. FEVER / HYPERTHERMIA
Dr.Mohamad Shaikhani.

2. Normal & variations:
•The mean oral temperature is 36.8+/- 0.4C (98.2+/- 0.7_F), with
low levels at 6 A.M.& higher levels at 4 to 6 P.M.
•In women who menstruate, the A.M. temperature is generally
lower in the 2 weeks before ovulation; it then rises by about 0.6 C
( 1 F) with ovulation& remains at that level until menses occur.
•Body temperature is elevated in the postprandial state.
•Elderly individuals have a reduced ability to develop fever, even
in severe infections.

3. Common Sites for Temperature MeasurementCommon Sites for Temperature Measurement
UsesUsesConsConsProsProsSiteSite
Most common site in
adults and children
over 5.
Affected by eating,
drinking, etc.
Temperature varies
within oral cavity.
Hard to keep
thermometer in place,
esp. if edentulous.
Easy access
Familiar
Minimally invasive
Oral cavityOral cavity
Often requested by MDs as
the 'most accurate'
site for core
temperature.
Site records highest temp
in body. Lags behind
other core sites when
temp is changing
rapidly.
Preferred by MDs.RectumRectum
Most common site in
children under 5.
Sometimes used
during surgery.
Reflects skin temperature.
Not always a good
indicator of core
temperature.
Must be held in place.
Takes long time to
reach equilibrium.
Easy access
Familiar
Minimally invasive.
Preferred by
American Academy of
Pediatrics for use in
infants.
AxillaAxilla
Commonly used in
hospitals and clinics.
Requires thorough training
and attention to
technique.
Easy access
Familiar
Minimally invasive.
Two sites available.
Reflective of brain
temperature.
EarEar
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4. Body Normal TemperatureBody Normal Temperature
36.8 cMouth
36.4 cAxilla
37.7 cRectum
36.8 cEar
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5. Electronic/Disposable Thermometer



Skill 31-1: Step 6C(7). Thermometer tip in
axilla.
View

6. Fever
•Elevation of body temperature that exceeds the normal
daily variation& occurs in conjunction with an increase in
the hypothalamic set point
•The processes of heat conservation (vasoconstriction)&
heat production (shivering / increased metabolic activity)
continue until the temperature of the blood bathing the
hypothalamic neurons matches the new thermostat setting.

7. Fever
•The daily highs& lows of normal temperature are exaggerated
in most fevers, but reversed in typhoid fever& disseminated
TB.
•Temperature-pulse dissociation (relative bradycardia) occurs
in typhoid fever, brucellosis, leptospirosis, some drug-induced
fevers, and factitious fever.
•In newborns,elderly, CRF&patients taking glucocorticoids,
fever may not be present despite infection, or core
temperature may be hypothermic.
•Hypothermia is observed in patients with septic shock,
hypothyroidism & cold exposure.

8. characteristic patterns.
•Of clinical benefit only in malaria.
•Relapsing fevers, febrile episodes are separated by intervals of
normal temperature:
•Tertian:when paroxysms occur on the first& third daysas in
Plasmodium vivax
•Quartan fevers associated with paroxysms on the first & fourth
days,seen with P. malariae.
•Borrelia infections& rat-bite fever, both associated with days of
fever followed by a several-day afebrile period& then a relapse of
days of fever.
•Pel-Ebstein fever, fevers lasting 3 to 10 days followed by afebrile
periods of 3 to 10 days, is classic for Hodgkin’s disease& other
lymphomas.
•Cyclic fever, fevers occur every 21 days& accompany cyclic
neutropenia.
• Hectic Fever: Daily elevated temperature (>38 C or 100.4 F).

9. Continuous fever

10. Remittent:

11. Intermittent:

12. Undulant:

13. Relapsing:

14. Irregular:

15. How to Classify Fever?
•Fever can be classified in two
ways:
1- Continued, Intermittent,
Remittent, Relapsing.
2- Acute, Chronic.
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16. Types
examplescharactertype
Typhoid fever, typhus, drug fever,
malignant hyperthermia.
Does not remitContinued
Pyogenic infection, lymphoma,
military T.B.
Temperature falls to
normal everyday
Intermittent
Not characteristic for any
particular disease.
Daily fluctuation >2c
.temperature dos not
return to normal
Remittent
Malaria:
tertian-3days pattern, fever peaks
every other day (plas. Vivax,
plas.ovale), quatrain-4day
pattern . fever peaks every
third day (p.malaria)
lymphoma:
HODJKIN lymphoma
Pyogenic infection
Temperature returns to
normal for days before
rising again
Relapsing
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17. Hyperpyrexia:
•A fever of >41.5C (>106.7 F).
•Can develop in patients with severe
infections but most commonly in patients
with CNS hemorrhages, tumor, or
intrinsic hypothalamic malfunction.

18. HYPERTHERMIA
•Hyperthermia is characterized by an unchanged (normothermic)
setting of the thermoregulatory center in conjunction with an
uncontrolled increase in body temperature that exceeds the body’
ability to lose heat.
•Heat stroke
•Drug-induced hyperthermia by MAOIs, tricyclic antidepressants,
& amphetamines,phencyclidine (PCP), LSD, or cocaine.
•Malignant hyperthermia occurs in individuals with an inherited
abnormality of skeletal-muscle sarcoplasmic reticulum that
causes a rapid increase in intracellular calcium levels in response
to halothane& other inhalational anesthetics or to succinylcholine.

19. HYPERTHERMIA
•The neuroleptic malignant syndrome (NMS) with neuroleptic use
(antipsychotic phenothiazines, haloperidol, prochlorperazine,
metoclopramide) or the withdrawal of dopaminergic drugs
characterized by “lead-pipe” muscle rigidity, extrapyramidal side
effects, autonomic dysregulation& hyperthermia.
• The serotonin syndrome, seen with (SSRIs), MAOIs& other
serotonergic medications, has many overlapping features,
including hyperthermia, distinguished by diarrhea, tremor,
myoclonus rather than the leadpipe rigidity of NMS.
•Thyrotoxicosis&pheochromocytoma can also cause increased
thermogenesis.

22. FUO or PUO:
•Classical FUO.
•HIV FUO.
•Neutropenic FUO.
•Nosocomial FUO.
•Fever >38 c persisting for >3 weeks with
no clear diagnosis with one week
intelligent& intensive investigation.

23. Causes of FUO:
•BIG 3
–Infection
–Neoplasm
–Autoimmune diseases
•Little 6
–Drug fever
–Granulomatous diseases
–Regional enteritis
–Familial Mediterranean fever
–Pulmonary emboli
–Factitious fever

24. Treatment:
•Oral aspirin & acetaminophen are equally effective in
reducing fever.
•NSAIDs as indomethacin / ibuprofen are also excellent
antipyretics.
•As effective antipyretics, glucocorticoids; cyclooxygenase
inhibitors, reducing PGE2 synthesis & block the transcription
of the mRNA for the pyrogenic cytokines.

25. Treatment:
•Treating fever& its symptoms does no harm or slow the
resolution of common viral& bacterial infections.
•Reducing fever with antipyretics also reduces systemic
symptoms of headache, myalgias& arthralgias.
•Oral aspirin& NSAIDs effectively reduce fever but can
adversely affect platelets &GIT, so acetaminophen is
preferred as an antipyretic.
•In children, acetaminophen must be used because aspirin
increases the risk of Reye’s syndrome.
•If the patient cannot take oral antipyretics, parenteral
preparations of NSAIDs& rectal suppository can be used.

26. Treatment:
•Treatment of fever in some groups of patients is specially
recommended.
•Fever increases the demand for oxygen (i.e., for every increase
of 1C over 37C, there is a 13% increase in oxygen
consumption) aggravating preexisting cardiac,
cerebrovascular, or pulmonary insufficiency.
•Elevated temperature can induce mental
changes/hallucinations in patients with or without organic
brain disease.
•Children with a history of febrile or nonfebrile seizure should
be aggressively treated to reduce fever.
•In hyperpyrexia, the use of cooling blankets facilitates the
reduction of temperature; but should not be used without oral
antipyretics.
• In hyperpyretic patients with CNS disease or trauma,
reducing core temperature reduces the ill effects of high
temperature on the brain

27. Treatment: Hyperthermia
•Antipyretics& attempt to lower the already normal hypothalamic
set point is of little use.
•Physical cooling with sponging, fans, cooling blankets&ice baths
should be initiated immediately with IVF &appropriate
pharmacologic agents.
• Internal cooling can be achieved by gastric or peritoneal lavage
with iced saline.
•In extreme circumstances, hemodialysis or even cardiopulmonary
bypass with cooling of blood may be performed

28. Treatment: Malignant hyperthermia
•Immediate cessation of anesthesia & use of IV dantrolene.
• Procainamide should also be used because of the likelihood of
VF.
•Dantrolene also is indicated in NMS& in drug-induced
hyperthermia& may even be useful in the hyperthermia of the
serotonin syndrome& thyrotoxicosis.
•NMS may also be treated with bromocriptine, levodopa,
amantadine, or nifedipine or by induction of muscle paralysis
with curare / pancuronium.
•Tricyclic antidepressant overdose may be treated with
physostigmine.