Elevation of creatine kinase is associated with worse outcomes in 2009 pH1N1 influenza A infection

Intensive Care Medicine, 05/03/2012

Borgatta B et al. – Creatine kinase (CK) is a biomarker of severity in pH1N1 infection. Elevation of CK was associated with more complications and increased intensive care unit (ICU) length of stay (LOS) and healthcare resources.


  • A prospective multicenter register included all adults admitted for severe acute respiratory insufficiency (SARI) with confirmed pH1N1 in 148 ICUs.
  • Clinical data including demographics, comorbidities, laboratory information, organ involvement, and prognostic data were registered.
  • Post hoc classification of subjects was determined according to CK level.
  • Data are expressed as median (interquartile range).


  • Five hundred and five (505) patients were evaluable.
  • Global ICU mortality was 17.8 % without documented differences between breakpoints.
  • CK ≥500UI/L was documented in 23.8 % of ICU admissions, being associated with greater renal dysfunction: acute kidney injury (AKI) was more frequent (26.1 versus 17.1 %, p<0.05) and twofold requirement of RRT [11 versus 5.6 %, p<0.05; odds ratio (OR)=2.09 (95 % confidence interval [CI] 1.01-4.32)].
  • Increase of CK ≥1,000UI/L was associated with two or more quadrant involvement on chest X-ray (63.2 versus 40.2 %, p<0.01) and increased intubation risk (73.9 versus 56.7 %, p=0.07) and duration of mechanical ventilation (median 15days versus 11 days, p<0.01).
  • As a result, CK ≥1,000UI/L was associated with 5 extra days of ICU and hospital LOS.

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