Influenza

OVERVIEW

  • caused by influenza A and B viruses

CLINICAL FEATURES

  • fever (>38 C)
    +/- one systemic symptoms (myalgia)
    +/- one respiratory symptoms
    -> 70% chance of having influenza

INVESTIGATIONS

  • nasopharyneal viral swab

MANAGEMENT

Active Treatment

  • neuraminidase inhibitors are of no benefit unless started within 48 hrs of patient developing symptoms
  • even if started within 48 hours -> will only shorten duration of illness by 1 day
  • does reduce incidence of complications
  • resistance has emerged
  • oseltamivir 75mg Q12 hrly for 5/7 or until swab negative (2mg/kg)
  • zanamivir 10mg INH Q12 hrly for 5/7

Prophylaxis

  • current influenza vaccine prior to winter
  • vaccination for at risk groups – health care workers, > 65 years, Aboriginal/Maori/PI > 50 years, specific chronic diseases
  • can use neuraminidase inhibitors after exposure

SWINE-ORIGIN INFLUENZA VIRUS

  • SOIV = H1N1 = sub-type of influenza A -> caused the pandemic of 2009
  • caused 17,000 deaths by the start of 2010
  • infection caused any of the influenza viruses endemic in pigs

Particular important characteristics:

  • complete dominance over the seasonal influenza viruses
  • severely effected = pregnant, children < 2, respiratory condition, immunosuppression, obesity
  • case fatality rate of 1.3%
  • respiratory conditions = obesity, asthma, COPD
  • immunocompromised = solid organ transplant, bone marrow transplant, cancer

Pulmonary Complications

  • death (typically aged 15-60 yrs)
  • pneumonia
  • superinfection (MRSA, Streptococcus pneumoniae, S. aureus, streptococcus pyogenes, H. influenzae, Streptococcus mitis, atypical pneumonia, Aspergillus)
  • VAP (Pseudomonas aeruginosa, Acinetobacter baumannii, MRSA, E. coli)
  • ARDS
  • PE

Extra-pulmonary Complications

  • pericarditis
  • myocarditis
  • renal failure
  • elevated CK -> rhabdomyolysis
  • encephalitis/cerebritis -> seizures

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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