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

Design

• RCT, computer generated randomisation
• Non-blinded

Setting

• Single general ICU, Israel
• May – December 2007

Population

• 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

Intervention

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

Control

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

Outcome

• 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

Strengths

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

Weaknesses

• 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 longer 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