Fever Flashcards
What determines core body temp
- core body temp
- t emp of blood surrounding hyppothalamus (test is v invasive)
*very different than skip temp
what is responsible fpr thermoregulation
- hypothamalus
- maintains core body temp at 37 C via neg feedback between thermoregulatory center in hypothalamus and thermosensitive neuron in skin and CNS
- compensatory physiologic mechanisms and behavioural adapt help to return temp to normal
why must you refer an infant with a fever
- infants < 3 months have an immature thermoreg system & are incompletely vaccinated
*hard to get a fever so if they have one something is likely very wrong
Describe the heat dissipating phase
- mech of maintain homeostasis
- peripheral vasodilation to promote heat loss: skin feels hot, flushing,
- sweating (cholinergic
- head ache
- behavioural: remove clothing, adjust air conidtioning, seeking shade from hot sun
Describe the Heat-generating Phase
- peripheral vasocontriction to prevent heat loss -> inc HR, malaise (general feeling of unwell)
- involuntary skeletal muscle contraction -> shivering, chills
- increase catabolism
- behavioural: wearing additional chlothing, rub hands together
how does normal body temp vary daily
- according to circadian rhythms
- lowest in AM
- highest late afternoon (4-5)
*varies daily be 0.5-1 C
what is normal temp range
rectally
tympanically
orally
axillary
temporally
Rectally: 36.6 - 38
Tympanic: 35.7-38
Oral: 35.5 - 37.5
Axillary 34.7 - 37.2
Temporal 36.6 - 37.8
prevalence of fever
- 30% f children presenting to pediatricians have fever as complaint
- leader cuase of ER visits udner 15
- afftects 70% ICU
what temperature is:
fever
high fever
hyperrexia
Fever: T > 38 (rectally ( remove 0.6 or oral)
High fever: T > 40.5 oral
Hyperpyrexia: T > 41.1 C
What temp is fever
rectally
tympanically
orally
axillarly
temporally
Rectally: > 38C
Tympanically >38
Oral > 37.5
Axillary > 37.2
Temporal *depends on pt age and device used (prov over 37.8
what causes a fever?
Pyrogens
- Exogenous
- Microorganisms and toxins
- Induce formation and release of endogenous pyrogens (act to inc PGE2)
- ex: gram -ve bacteria have exogenous pyrogens, fungi, virus, clood prod, drugs (amphotericin B) or excipients (EDTA)
- Endogenous
- Polypeptides produced by host cell macrophages, monocytes and other cells in response to or from damaged tissu
- IL-1α & IL-1β, TNFα, IL-6, CNF and IFN-Υ (act to increase PCE2 -> inc set point)
- their release causes symptoms such as nyalgias and arthralgias (muscle aches and pains)
- Polypeptides produced by host cell macrophages, monocytes and other cells in response to or from damaged tissu
Pathophysiology
- Inection, toxins, injury, ifnlammation
- Immune Response mediators
- IL-1 IL-2 TFN IFN
- Leukocytes
- monocytes, neutrophils, lymphocutes
- endothelium, glial cells, mesenchymal cells
- Pyrogenic Cytokines
- IL-1, TNF, IFN
- Hypothalamic endothelium
- production of PGE2 **treat fever with inhibitors of PGE2
- rise in cAMP
- Elevated Set point
- activation of vasomotor centre neurons
- peripheral vasocontriction and heat production
an increase in body temp may be _____ or _____
- idopathic or the result of infectious and other pathologic processes, systemic response to certain drugs and vigrous activity
What are the ifnectious causes of Fever
Airway: Pharyngitis, sinusitis, dental infection
- Respiratory system: Pneumonia, bronchitis
- Circulatory system: Endocarditis, myocarditis
- Central nervous system :Meningitis, encephalitis
Endocrine system : Prostatitis
Renal/urinary tract: Cystitis, pyelonephritis
- Gastrointestinal tract: Pancreatitis, C. difficile colitis
- Integument: Cellulitis, necrotizing fasciitis
What are the non infectious causes of fever
CNS inflammation
Malignancies & Neoplasms
Tissue Damage
Dehydration
Metabolic Disorders
Immunologically-Mediated Conditions: Antigen-Antibody Reactions -> Drug Fevers (drug-induced hyperthermia)
What is hyperthermia
- uncontrolled elevation in body temp without elevation of the hypothalamic set point
*represents a malfunctioning of the normal thermoregulatory process at hypothalamic level
- usually caused by inadephate heat dissipating in response to warm env
*young children and early adults prony to heat stroke
- Antipyretic agents not efective in lowering body temp **Can be rapidly fatal
if have hypothermia treatmeith w/ NSAID will do NOTHING
what is drug induced hyperthermia
- accounts for 3-5% of all ADR (not common
- occurs in 10% hospitalized pat (bc usuall on many drugs)
- body unable to maintain core temp (ranges from 38.8-40 but could reach 42.2)
- foten goes unrecognized bc of inconsistent signs and symptoms
- management = disc suspected drug (failure to do so can cause substancial borbidity and mortabilty
caused by: antineoplastis, cardobascular agents, CNS agents, anti-infectives, other agents
what are the 5 categories of drugs that can induce fever
- antiinfectives
antineoplastics
cadiovasucular agents
CNS agents
- other agents
aspects to aplying PPCP to fever
- demographics: name, age, weight *always ask if consult is for that person or somebody else
- SCHOLAR: gives info about cheif complaints
- HAIMS: tells aobt patient
Scholar for fever
- Symptoms
- main and assocaited symptoms
- Characteristics
- QOL
- Daily activities
- did he go to day care are pthers around him sick
- Histroy
- happened in past
- what as done then
- where ddi you measure temp what was temp
- has fever fluctuated in this episode or used in medication
- Pmset
- when did this episode fever begin
- what time did yu measure
- when did this episode fever begin
- location
- whre is problem
- Agrvsting factors
- what akes symptoms worse
- Remitting factors
- what maeks feel better
wha signs and symptoms typically accompany fever
headache
•backache
•diaphoresis
•clammy skin
•flushing
•tachycardia
•chills
•somnolence
•arthralgia
•myalgia
•irritability/ crying
•anorexia
•generalized malaise
•tachypnea
how do most children tolerate fever
- well
- if continue to be alert, play formally
and stay hydrated fever is not great concern
Collecting HAMS for fever
- Health Status
- condition, wellnes (immunizations), diagnostics, physical assessemnt
- obtain accurate temp measurement: pat age, time of day, level of physical & emotional stress
- Allergies/intolerances
- drugs or env
- Medication histroy
- Rx, OTCs, NHPs, Recreational
- Socail histroy
- lifestyle (daycare, school, diet, water)
- beliefs, goals and preferences
- socioeconomic factors
what is bold standard for measuring body temp
- rectal: consistenyl estimates core body temp
CI: recent anorectal surgery, injury, pathology, premature infants, severe hemorrhoids
- can produce BM in infants
What is traditionally most popular method to measure body temp
CI: lethargy, confusion, when nasal breathing is difficult
- wait over 10 min after oral cavity has been heated or cooled (after smoking, or ice cream)
use of tympanic for measuring temp
- alternative to rectal and roal methods: convenient, noninvasive, quick ( <2 sec)
- dec accuracy with inproper palcement; expensive
- COP does not reccomend t for less than 2 y/o (others say less than 6 months)
^bc ear canal not large enough for daimeteer -> cant get reading in
non contact infrared, axillary and temp strips as methods to take temp
Non contact
- alternative to rectal and oral method
- convenient and non invasive, quick
- prone to error
Axillary
- unreliable and elast accurace -> used to screen for fever
- acessible, safe, less, frightening
- affected by hypotension, cutaneous vasodilation, prior cooling of patient
- ust be helf under armpit for up to 5 min
Temp strips
- contain liq crystals that register temp by changing colours
- nor accurate and not reccommended for temp measurement
Chosing temp method for:
- Birth to 2 years:
- rectal (gold standard)
- axillary
- Over 2 years - 5 years
- recetal
- axillary, tympanic (or temporal artery if in hospital for screening
- Older than 5
- oral
- axillary, tympanic
what hermometer would you recommend for someone on a budget
digital probe
When you believe a patient has a fever how would you assess them
- analyze ifno collected and identify any real or potential drug therapy problems
*medications need to be Indicated, effective safe and something they can adhere to
*look for red flags
*most feveres are self limiting but can cause a lot of discomfort, could indicate underlying pathologic condition that required prompt medical evaluation
what are exclusions for fever self treatment that would warrent emergeny referral to hospital
Age < 3 months
- Presence of stiff neck (pot meningitis), seizure, localizedpain, redness, swelling or heat
- New wheeze/cough
- Recent cancer therapy (could be caused by the agent)
- Child appearing very ill, excessively fussy, irritable, crying inconsolably or other symptom(s) worrying theparents/caregivers (e.g., difficult to rouse, confused or delirious)
what are exclusions for fever self treatment that would warrent referal to primary care provider
- Age 3-6 months (esp if not fully vaccinated)
- High fever
- Persistent wheeze/cough
- New onset rash and fever
- Dehydration/vomiting (if serious could have suke in fontanel, tearless crying, ask colour of urine of child)
- Recent surgery or dental procedure
- Recent travel (pot food poisoning)
- Recent consumption of raw or undercooked meat or fish
- Recent initiation of new medication
- Fever has not resolved after 72 h
What pateints with fever can safely self treat?
Fever lasting 3 days or less, fever less than 40.5 and no red flags present
*must have all 3 of these
reasons against OTC treatment of fever
- Fever is usually benign andself-limited
- Fever is an important defensemechanism that enhances theimmune system
- The possible elimination of avaluable diagnostic or prognostic sign
- Possible AE’s of antipyretic medications
reasons for treatment of fever w/ OTC
Enhanced QOL: relieve symptoms associated with fever that may cause substantial discomfort
- Treatment of fever does little harm and has not been shown to clinically alter the course of common bacterial and viral infections
when treating children you must
treat the child not the number
- a child w/ fever temp but not presenting symptoms would not really be candidate for OTC whereas somebody with a lower fever but really presenting symptoms would
what are non pharmacologic strategies for treating fever
- revove excess clothing/ bedding
- inc fluid intake (inc clear fluid by 1-2 oz/hour or 2-4 oz/hour if adult)
- avoid physical exertion
maintain ambient temp at 20-21 C
- sponde with tepid/cold water
(ONLY if give medication to lower set point because this will only decrease the skin temp. if you do this without giving an antipyretic they will feel hotter because their body is trying to compensate more)
- apple ice packs or cooling blankets (again same as above)
Treating fever with Acetaminophen
dose
max daily dose
onset
time to peak
duration
adv
other into
- Dose:
- Child: 10-15 mg/kg q4-6h PRN
- Adult: 1000mg
- Max daily dose
- neonates 60 mg/kg
- older infants/children 75 mg/kg *5 doses in a day
- adult: 4000 mg
- Onset
- <1 hr
- TIme to peak effects
- 2-4 hr
- Duration of effect
- for pain & fever: 4-6 hr
- Adverse effects
- uncommon with infrequent and recommended self care dose
- Other info/concerns
- **Acetaminophen is leading cause of acute liver failture
- hepetotoxicity in acute overdose or w/ therapeutic doses in certain conditions: chronic alc use (> 3 drinks/day, malnutrition, concurrent use of drugs inducing CYP450 enzymes
- **Acetaminophen is leading cause of acute liver failture
Treating fever with Ibuprofen
dose
max daily dose
onset
time to peak
duration
adv
- Dose
- child: 5-10 mg/kg q6-8h prn
- adult: 400
- Max daily dose
- child: 40 mg/lg
- adult: 1200
- Onset:
- <1 hr
- Time to peak effect
- 2-4 hours
- Duration of effect
- pain: 406 hr, fever 6-8 hr
- Adv effects
- Uncommon with infrequent use and recommended self care dose
- Other info/concerns:
- CVD: hypertension
- HI: dyspepsia, abdominal pain, nephrotoxicity in children with: pre-existing renal disease, dehydration, concurrent nephrotoxic agents
**if you gave ibuprofen to a dehydrated chld they can get renal failure
what is combogesic
- combination of 325 mg acetaminophen and 97.5 mg ibuprofen
*inly indicated in adults and not yet indicated for fever
what is the mechanism of action of aspirin and toher NSAIDs
- block cyclooygenases which stop prostaglandind from being rpoduced both centrally and in periphery
- acetaminophen MOA not well understood - not an NSAID and deos NOT stop prostaglandin synthesis peripherally, but does work as a cyclooxygnase inhibitor
teating children with naproxen
- Dose
- Children 12 years and older: 220 mg q8-12h
- adults: same
- Max daily dose
- 440 mg (self care)
- Onset
- <1 hr
- Duration of effect:
- 7-12 hr
- Adverse effects
- dyspepsia, NV, abdominal pain, dizziness, headache
- Other info/concerns
- avoid use in fever for <12 years of age
- nephrotoxicity in children with pre exisitng renal disease, dehydration, nephrotoxic agents, CVD
Treatment of fever with aspirin
- ONLY for adults *dont give to children bc of Reyes
*only treats pain? ask
- Dose
- 325-650 mg q4-6 h
- Max daily dose
- 4000 mg
- Onset
- <1 hr
- Duration of effect
- 4-6 hr
- Adverse effects:
- Dyspepsia, tinnitus, plateley dysfunction, GI mucosal damage
- Other info/concerns
- avoid in < 18 bc those with viral illness may get Reyes syndrome
- avoid in pat with renal failure, peptidic ulcer disease, heart failure and ASA sensitive asthma
*
Infrant drops vs children liquid tylenol
* infrant drop = 80 mg/mL childrens liquid =160mg/5mL (32 mg/mL)
*caused a lot of unintended overdosing
acetaminophen vs ibuprofen
- basically equal efficacy
- acetaminophen for a while was 1st choide becuase had more safety data, now have lots for both
- ibuprofen may be more efefctive in treating fever: some evidence that it lowers temp faster and for longer duration
- inbuprofen also seems better at reducing “distress” in treatment of fever in children
- ibuprofen also seems to be better with respect ot temp control within 4 hours of first dose
what is said about combining acetaminophen and ibuprofen?
- combo antipyretics dont work faster but are longer acting in the first 24 hours
- canadian piediatric says: adding acetaminophen (paracetamol) to ibuprofen does not reduce fever faster than ibuprofe alone in children. Over 24 h children receieving the combo spend 2.5 - 4.4 hours without fever than children who took either drug alone
* AAP and CPS do NOT recommend because: risk of overdose, risk of dosing errors and inc adv effects
- insufficient evidence to show combo therapy is effective in improving overall comfort level
- it is okay to initate treatment with one but then switch fully to the toher if parients fever does not respond well to initial agent
Febrile Seizures
* fi ahve them is grounds for referral
- occur once within first 24 hours period in febrile child with no underlying neurological history of infection
- incidence: 2-5% of febrile episodes n children aged 6 months -5 years
- neurological damage or permanent seizure disorders are RARE
*antipyretics often recommended for children in this age group, no role for anticonvulsants
*given an antipyretic at 1st sign of fever MAY prevent recurrent febrile seizures
Steps for implementing treatment of fever
- Address medication and health related problems
- initiate, modify, disc or administer mediation therapy
- proivde education and self management training
- contribute to coordination of care
- schedule follow up care as needed to achieve goals of therapy
how shoudl you educate a patient in taking mediactoin for fever
- if not providing mediaction, explain expceted source of illness and outline red flags that would necessitate reassessment
- explain how to optimally take med (calc amount for them, say shake well if susp, throw out dosing cup and give syringe)
- discuss how to manage issues that amy arise
- eucate on implementarion of diet, exercise, other lifestyle changes
- provide tools to empower the patient to become advocate for theri health
educating on SAFE use of acetaminophen
S: Signifiacne of acetaminophen toxicity
“well tolerated but if you take too much can get liver damage”
A: Limit alcohol consumption
*again heptotoxicity
F: find all sources of acetaminophen in regimen
*acetaminophen is in 470 products, make sure ntohing else taking ahs it
E: avoid exceeding the max daily dose
*acet overdoses accounts for ~50% of all cases of acute liver failure
* if child has temp that last 3 days or if child has temp and is less than 6 motnhs
SEE DOCTOR IMMEDIATELY
How can you help manage fever phobia
- inform that it will take 72 H to get over it
tell them what temperature to watch out for
- only should really be testing temp 2-3 x/day
How to monitor and evalure fever
- Fever Reduction
- desired outcome = temp reduction
- should change after otc in 1-2 h
- minotor max 2-3 times a day, if child acting fine dont worry too much
- Discomfort
- desired outcome = 50% reduction
- time frame for chane = 2-3 hours after OTC
- monitor daily
- Side effects
- desired outcome = none
- could happen thoguhout course of therapy -> minitor daily
*Rph to follow up 2-3 days
