Singer: The tight calorie control study (TICACOS): a prospective, randomized, controlled pilot study of nutritional support in critically ill patients

Singer et al. Intensive Care Med 2011; 37(4):601-609.

Clinical Question

  • Does nutritional support guided by measurements of resting energy expenditure (REE), compared with a weight-based regimen, improve survival in critically ill patients


  • RCT, computer generated randomisation
  • Non-blinded


  • Single general ICU, Israel
  • May – December 2007


  • Adult patients who were mechanically ventilated with an expected ICU stay >3 days
  • Important exclusion criteria: FiO2 >0.6; on renal replacement therapy; head trauma with GCS <8; open heart surgery
  • 944 patients screened of whom 130 eligible


  • Tight calorie group: energy goal determined by daily REE measurements using Deltrac II metabolic monitor


  • Energy goal based on pre-admission weight (25kcal/kg/day)


  • Primary outcome: hospital mortality
    • 32.3% in tight calorie group vs. 47.7% in control group, P=0.058
  • Secondary outcomes
    • comparing tight calorie group to control group
      • Mean target energy (kcal/day) 1,976 vs. 1,950
      • Mean energy delivered (kcal/day) 2,086 vs. 1,480, P=0.0
      • Received parental nutrition during the 1st three days of the study 26% vs. 9%, P=0.02
      • Length of ventilation 16.1 vs. 10.5 days, P=0.03
      • ICU stay 17.2 vs. 11.7 days, P=0.004

Authors Conclusions

  • Nutritional support guided by REE may be associated with a lower mortality


  • Appropriate primary outcome
  • Used protocol to maintain glucose <150mg/dL in all patients
  • Intention to treat analysis


  • Non-blinded
  • Single centre
  • Small number of patients
  • No Power calculation
  • Groups treated differently
    • In the intervention group the dietician in charge of the study was responsible for achieving the energy targets whereas in the control group this was the responsibility of the ward staff
    • In the intervention group they consistently exceeded the target energy delivery whereas in the control group they consistently failed to achieve the target energy delivery
  • Conflicting results with longerĀ length of mechanical ventilation and ICU length of stay in the intervention group, but lower mortality. Is this biologically plausible?
  • Non-nutritional energy was not taken into account
  • Conflicts of interest not reported

The Bottom Line

  • The poor study design with major differences in the way the two study groups were treated invalidates the results and we are unable to tell if nutritional support guided by REE improves outcomes compared with a weight based regimen.
  • Having a dedicated dietician improved achievement of target nutrition


Full text pdf / abstract / doi:Ā 10.1007/s00134-011-2146-z

Editorial, Commentaries or Blogs

  • None listed


Summary author: @DavidSlessor
Summary date: 1 May 2014
Peer-review editor: @stevemathieu75

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