Associations between nutritional energy delivery, bioimpedance spectroscopy and functional outcomes in survivors of critical illness.

BACKGROUND: Patients who survive critical illness frequently develop muscle weakness that can impact on quality of life; nutrition is potentially a modifiable risk factor. The present study aimed to explore the associations between cumulative energy deficits (using indirect calorimetry and estimated requirements), nutritional and functional outcomes. METHODS: A prospective single-centre observational study of 60 intensive care unit (ICU) patients, who were mechanically ventilated for at least 48 h, was conducted. Cumulative energy deficit was determined from artificial nutrition delivery compared to targets. Measurements included: (i) at recruitment and ICU discharge, weight, fat-free mass (bioimpedance spectroscopy) and malnutrition (Subjective Global Assessment score B/C); (ii) at awakening and ICU discharge, physical function (Physical Function in Intensive Care Test-scored) and muscle strength (Medical Research Council sum-score (MRC-SS). ICU-acquired weakness was defined as a MRC-SS score of less than 48/60. RESULTS: The median (interquartile range) cumulative energy deficit compared to the estimated targets up to ICU day 12 was 3648 (2514-5650) kcal. Adjusting for body mass index, age and severity of illness, cumulative energy deficit (per 1000 kcal) was independently associated with greater odds of ICU-acquired weakness [odds ratio (OR) = 2.1, 95% confidence interval (CI) = 1.4-3.3, P = 0.001] and malnutrition (OR = 1.9, 95% CI = 1.1-3.2, P = 0.02). In similar multivariable linear models, cumulative energy deficit was associated with reductions in fat-free mass (-1.3 kg; 95% CI = -2.4 to -0.2, P = 0.02) and physical function scores (-0.6 points; 95% CI = -0.9 to -0.3, P = 0.001). CONCLUSIONS: Cumulative energy deficit from artificial nutrition support was associated with reduced functional outcomes and greater loss of fat-free mass in ventilated ICU patients.

Impact of increasing overnight intensive care unit registrar staffing on duration of intubation of elective cardiac surgery patients.

It is unclear whether increases to overnight junior medical staffing levels can improve ICU patient outcomes. We conducted a retrospective cohort study before and after the introduction of a third overnight ICU registrar at a 24-bed metropolitan ICU in February 2012. We hypothesised that this change would be associated with decreased intubation time for elective cardiac surgery patients and an increase in the proportion of these patients being extubated during the overnight period. All elective cardiac surgery patients were included from two temporally matched six-month periods (May to October) in 2011 and 2012. The primary outcome was median duration of intubation, and the secondary outcome was proportion of patients extubated during the 'overnight' period (2200 to 0700). A total of 142 and 188 patients were included in the control and intervention cohorts, respectively. Median (IQR) intubation time was 8.7 (6.6 to 14.5) hours in the control cohort and 8.2 (6.0 to 13.4) hours in the intervention cohort, with no significant difference between groups (P=0.40). The proportion of elective cardiac surgery patients extubated during the overnight period was similar, 54.2% in the control group compared to 50.0% in intervention group (P=0.45). In our unit, increasing overnight ICU registrar staffing levels was not associated with a significant reduction in duration of intubation for elective cardiac surgery patients or a reduction in the proportion of these patients extubated overnight. This is likely due to factors other than medical staffing levels influencing timing of extubation of these patients.