The febrile adult presenting to the ED

see also:

• sepsis, SIRS and septic shock
• infectious diseases
• fever - the febrile response to infections
• NSW CEC Sepsis Kills program
• NSW CEC adult sepsis pathway chart (pdf)

• the following features in particular demand triage category of 1 or 2 and urgent resuscitation, investigations & empirical Rx:
  • shock (systolic BP < 90, MAP < 65 or serum lactate > 4) - see sepsis, SIRS and septic shock
  • the comatose patient/stupor
  • cyanosis
  • profound SOB
  • continuous seizures
  • severe dehydration
  • petechial rash in a febrile patient - see meningococcaemia
  • headache and neck stiffness - see meningitis

• new onset of confusion or decreased mental state
• temp > 38.5degC or temp < 35.5
• HR < 50 or HR > 120
• systolic BP < 100 mmHg
• SaO2 < 95%
• see sepsis, SIRS and septic shock

• age > 65yrs
• immunocompromised (eg. on chemotherapy, organ transplant recipient or on steroids)
• fevers / rigors
• recent surgery
• implanted device
• fall
• signs or symptoms of infection:
  • skin - cellulitis or wound
  • urine - dysuria, frequency, malodour
  • abdominal pain
  • chest - cough or SOB
  • neuro - headache, neck stiffness, or mental state change

• early senior medical consult and resuscitation as per sepsis / septicaemia

• early medical assessment
• iv access, FBE, U&E, blood cultures
• iv fluids
• iv antibiotics within 60 minutes preferably if considered possible sepsis

• examine and Ix for sources of infections:
  • chest
  • abdomen
  • meningitis
  • skin
  • urine
  • joints / bone
• BUT be aware of 3 main traps:
  • focal symptoms and signs may not be present or obvious early in the course of infection:
    • rash in measles
    • cough in pneumonia
    • diarrhoea in gastroenteritis
  • localised features may be misleading:
    • diarrhoea may reflect septicaemia or appendicitis
    • RIF or RUQ pain may be due to pneumonia, pyelonephritis, etc
    • crepitations or effusion in the lung may be due to subdiaphragmatic conditions
    • early meningococcal rash may look like early measles rash
  • fever or delirium may be caused by non-infective causes such as:
    • intracerebral event such as subarachnoid haemorrhage (SAH), subdural haemorrhage, stroke (CVA)
    • drug toxicity or overdose
    • alcohol or opioid withdrawal

• often do not mount much of a febrile response & fever may be absent in 20-30% with serious infections
• infections often present with non-specific or atypical presentations
• a temperature higher than 38degC is highly suggestive of a serious infection
• UTI and pneumonia are the most frequent infections but focal symptoms are frequently absent
• urinalysis & CXR will identify ~50% of occult infections
• any unexplained fever in persons > 50yrs age should be regarded as being bacterial and should generally be admitted to hospital
• most elderly patients who are not NFR and who have a delirium should have:
  • FBE, U&E, glucose
  • ECG to exclude AMI
  • CT brain
  • CXR
  • urine culture
  • bladder scan to exclude retention
  • consider a lactate level / VBG

• often present with multiple problems, many of which cause fever
• the commonest infection is pneumonia
• non-infectious causes of fever which usually require admission:
  • subarachnoid haemorrhage
  • alcohol withdrawal
  • alcoholic hepatitis
• admit if no obvious cause found

• most who present with fever have a serious infection such as:
  • cellulitis, pneumonia, vertebral osteomyelitis, infective endocarditis (including SBE)
• it is said that infective endocarditis (including SBE) is the cause of fever in 10-15% of intravenous drug users (IVDU) or injection drug use (IDU) patients who present to ED with a fever!¹⁾
• often have mixed organisms often Gram +ve and Gram -ve including anaerobes (eg. Klebsiella, Enterobacter, Serratia, Proteus) 
• soft tissue infections where endocarditis is not suspected usually require IV flucloxacillin 2g 6h + IV gentamicin 5-7mg/kg/d as a single daily dose
• a fever > 38.5degC in a pt who has used IV drug within past 5 days is sufficient indication for admission

• in general, IDDM pts, esp. if over 50yrs age, with fever & no source should be Ix and admitted
• foot infections tend to be mixed flora including anaerobes so usually require admission for:
  • ampicillin + gentamicin + metronidazole
  • exclusion of underlying osteomyelitis and surgical opinion

• ie. if febrile and absolute neutrophil count < 500/uL or <1000/uL and falling rapidly
• must be admitted for IV antibiotics regardless of their clinical appearance, as infections may become fulminant within hours, & clinical manifestations are frequently modified.
• see Sepsis in the oncology patient - febrile neutropenia

• should generally be admitted for IV antibiotics

• transplant pts or those with HIV / AIDS
• have a lower threshold for admission

• watch for imported infections such as malaria, typhoid fever, both of which need early diagnosis
• fever in a pt returning from malaria-endemic region should be considered malaria until proven otherwise
• see the febrile returned traveller

• animal handlers - zoonoses
• close contacts of meningococcal cases

• at higher risk of pyelonephritis so low threshold for admission if UTI
• avoid antibiotics not safe in pregnancy such as trimethoprim, tetracyclines, metronidazole
• certain viral infections may effect the fetus:
• contact with varicella when no PH exposure warrants serology & zoster Ig within 72hrs

• even in the absence of fever may be an early symptom of staph. or strept. bacteraemia
• also consider myositis or necrotizing fasciitis

• may be the sole presentation of sepsis, esp. in the elderly

• unexplained vomiting, esp. with headache or abdominal pain should raise concern
• do not attribute it to gastroenteritis in the absence of diarrhoea
• consider CNS infections & occult sepsis

• obviously meningitis is a concern and if not contraindicated, CT +/- LP should be considered
• if CSF is normal then before just attributing it to a viral infection, consider:
  • pneumonia, bacterial enteritis, cerebral abscess or prodromal bacterial meningitis

• regard as meningococcal until proven otherwise
• don't forget toxic shock syndrome - eg. tampons

• unlikely to be due to viral hepatitis & is more likely to be due to either of:
  • bacteraemia, cholangitis, pyogenic liver abscess, or non-vital infections such as malaria

• consider epiglottitis, retropharyngeal abscess, quinsy, infectious mononucleosis

• should be regarded as indicators of sepsis eg. abscesses, bacteraemia, endocarditis, cholangitis, pyelonephritis

• should be regarded as bacterial

• meningococcaemia
• falciparum malaria
• bacterial meningitis
• postsplenectomy sepsis
• toxic shock syndromes
• infections in the febrile neutropenic
• infective infective endocarditis (including SBE)
• necrotizing soft tissue infections
• space-occupying lesions of head & neck
• focal intracranial infections

• in general, admit if:
  • sick enough to warrant blood cultures
  • age > 50yrs, diabetic, alcoholic, IV drug user, immuno-compromised, or overseas traveller
  • those with clinical alarm bells as above
• if discharging home:
  • ensure you have current contact details clearly documented
  • ensure pt is seen by a doctor within 24-72hrs or earlier if:
    • T > 39degC then see within 24hrs
    • LP performed and normal then see within 6-12hrs