Diagnostic Approach of the Patient with Fever in ER: Diagnostic Approach of the Patient with Fever in ER 新 光 吳 火 獅 紀 念 醫 院 急 診 醫 學 科 林 秋 梅 92-07-05


Definition of fever: Definition of fever Elevation of body temperature above the normal circadian range, depend on approaching timing Based on individual situation, someone keeps relative low or high body temperature


DDx:Fever, hyperthermia: DDx:Fever, hyperthermia Fever, the balance is shifted to increase the core temperature Hyperthermia is an elevation of body temperature above the hypothalamic set point


Normal body temperature: Normal body temperature Diurnal variation Rectal temperature>0.6o C oral temperature Range: 36.8o C  0.4 o C to 37.7o C Fever: early morning >37.2o C PM >37.7o C


Methods to determine body temperature: Methods to determine body temperature Routine temperature measurements: oral, rectal settings Ear thermometry Intraesophageal infrared thermometry Lethal temperature: 43o C


Metabolic and physiologic responses in fever patient : Metabolic and physiologic responses in fever patient Metabolic rate increases 10~12%/1o C Increased insensible water loss, 300-500ml/m2/o C/day Heart rate increases of up to 15bpm/o C Electrolytes depletion


Pyrogens: Pyrogens Exogenous or endogenous Exogenous pyrogen-microorganism, their products, or toxins Endogenous pyrogens: by host, monocytes /macrophages


Fever inducing cytokines: Fever inducing cytokines Interleukin 1 and 1 - the most pyrogenic Tumor necrosis factor  Interferon Interleukin 6 cytokines>fever develop within 1h


Hypothalamic control of temperature: Hypothalamic control of temperature Body temperature is controlled by the hypothalamus 1. Preoptic anterior hypothalamus 2. Posterior hypothalamus Neurons receive two kinds of signals 1. Peripheral nerves 2. Blood bathing the region Initiate fever-arachidonic acid metabolites-PGE2


Why fever: Why fever Elevation of body temperature increases chance for survival Temperatures in the febrile range appear to increase the phagocytic and bactericidal activity of neurtrophils and the cytotoxic effects of lymphocytes Type III Pneumococci are particularly sensitive to nigh temperature and 41 o C grow poorly and may autolyze


Fever Patterns: Fever Patterns Intermittent fever Remittent fever Hectic fever Sustained fever Recurrent fever(Relapsing) Drug fever


Fever Pattern: Fever Pattern Fever pattern cannot be considered pathognomonic for a particular infection Hyperpyrexia> 41 o C , is an elevation of body temperature above the hypothalamic set point due to insufficient heat dissipation


Fever Patterns: Fever Patterns Fever with extreme fever: gram-negative bacteremia, Legionnaires‘ disease, and bacteremic pyelonephritis Noninfectious cause of extreme pyrexia: heat stroke, intracerebral hemorrhage, hemorrhagic pancreatitis Fever may sometimes absent:seriously ill newborns, elderly patients, uremic patient,significantly malnourished individuals, receiving corticosteroids or contineous treatment with anti-inflammatory or antipyretic agents


Reasons to treat fever: Reasons to treat fever To avoid potentially harmful secondary effects For the patient‘s comfort Methods of lowering temperature 1. Antipyretics a. Aspirin b. Acetaminophen c. Ibuprofen 2. Sponging the body 3. Cooling blankets 4. Turkish message of Weinstein


Accompaniments of fever: Accompaniments of fever Back pain, generalized myalgias, arthralgias, anorexia and somnolence Fever may be reduced by cyclooxygenase inhibitors Chills, CNS response to the thermoregulatory set point‘s call for more heat


FUO(Fever of unknown origin): FUO(Fever of unknown origin) Definition: febrile illness of more than 3 weeks‘ duration >38.3 o C on several determinations with no diagnosis reached after 1 week of study Classic FUO Nosocomial FUO Neutropenic FUO HIV-associated FUO


FUO: FUO Causes 1. Infection 2. Collagen vascular disease 3. Malignancy 4. Others Do not forget: abdominal abscess, endocarditis, hepatobiliary disease, TB, CMV infection


Approach to fever: Approach to fever Rule out common infection 1. Careful history: chronology of symptoms, use of drugs, surgical treatment, exposure 2. Physical examination 3. Basic laboratory screens a. Blood count b. Blood culture c. Urinary dialysis d. Urine culture e. CXR f. Stool examination


Approach to fever: Approach to fever Patterns of fever Alter the course of fever antipyretics, glucocorticords, and antibiotics etc. Reversed body temperature: typhoid fever, disseminated tuberculosis


Treatment of fever: Treatment of fever For comfort Hyperthermia 1.Heat stroke 2.Classic heat stroke 3.Drug-induced hyperthermia 4.Malignant hyperthermia


Definition: Definition Sepsis SIRS Severe Sepsis Septic shock Hypotension Refractory septic shock


Definition: Definition Sepsis: SIRS due to infection Bacteremia: presence of viable bacteria in the bacteria Hypotension: SBP40mmHg from baseline in the absence of other causes of hypotension Infection: microbial inflammatory response to the presence of microorganisms or the invasion of normally sterile host tissue by those organisms


Definition: Definition MODS(Multiple organ dysfunction syndrome): presence of altered organ function in an acutely ill patient such that homeostasis cannot be maintained without intervention Septic shock: sepsis with hypotension despite adequate fluid resuscitation, along with the presence of perfusion abnormalities Severe sepsis: sepsis associated with organ dysfunction, hypoperfusion or hypotension


Definition: Definition Systemic inflammatory response syndrome(SIRS) 1. Variety of causes 2. BT> 38 o C or 90/min 4. RR>20/min or PaCO2 12000 or 10%


Antibiotics using in ER : Antibiotics using in ER Pathogens,infection focus, host factors(Immune factors) Common infection in ER 1. UTI 2. Respiratory tract infection 3. CNS infection 4. Cellulitis


Antibiotics using-UTI: Antibiotics using-UTI Low urinary tract infection 1. Dysuria, low abdominal pain, frequency, urgency 2. E.coli, Proteus, Klebsiella etc 3. Antibiotics: Baktar, amoxicillin ,1 o cephalosporin duration: 3-7 days 4. Urinalysis continuing


Antibiotics using-UTI: Antibiotics using-UTI Upper urinary tract infection 1. Fever, flank pain, dysuria 2. Pyuria, bacturia=75% patient 3. 1 o or 2 o Cephalosporin  aminoglycoside, duration: 7-10 days 4. Renal sonography: intractable s/s,underlying disorder(DM,stone)


Antibiotics using-Respiratory tract infection: Antibiotics using-Respiratory tract infection Pneumonia 1. Cough, fever, sputum or not 2. CXR, clinical manifestations, sputum gram‘s stain 3. Labor pneumonia, interstitial pneumonia, atypical pneumonia, bronchopneumonia infiltration, consolidation, cavity, pleural effusion 4. Underlying disorders


Antibiotics using-Pneumonia: Antibiotics using-Pneumonia Streptococcus, H.influenzae,G(-) etc. Community- acquired pneumonia 1.G(+) Major, e.g. Penicillin agents 2.Young adult, dry cough, CXR-Mycoplasma 3. Fluminant course-3o cephalosporin+ macrolide+ anti-pseudomonas agent continuing


Antibiotic using-respiratory tract infection: Antibiotic using-respiratory tract infection Nosocomial pneumonia 1. Asp. Pneumonia-PCN+GM, or clindamycin+GM 2. G(-)-DM patient, consider K.P infection Empyema –drainage, anti-G(+) aminoglycoside


Antibiotics using-CNS infection: Antibiotics using-CNS infection Bacterial meningitis 1. Aggressive antibiotics-due to prognosis and sequence 2. Penicillin G+3o cephalosporin Vancomycin Viral meningitis 1. Observation, s/s Tx 2. Herpes meningitis- acyclovir continuing


Antibiotic using- CNS infection: Antibiotic using- CNS infection TB meningitis 1. Anti-TB agents 2. Prognosis: variation Fungal meningitis: antifungal agents


Antibiotics using-cellulitis: Antibiotics using-cellulitis Pathogens: common streptococcus, or staphylococcus Cellulitis  fasciitis  pyomyositis  osteomyolitis Progression: rapid means severe infection Antibiotics: PCN G or oxacillin


Pitfalls: Pitfalls Depend on laboratory data Incomplete Hx. PE Atypical presentation 1. Immunocompromised patient 2. Newborn 3. Early sign 4. Dehydration