How much underfeeding can the critically ill adult patient tolerate?

Critical illness leads to significant metabolic alterations that should be considered when providing nutritional support.Findings from key randomized controlled trials(RCTs)indicate that underfeeding(<70%of energy expenditure[EE])during the acute phase of critical illness(first 7 days of intensive care unit[ICU]admission)may not be harmful and could instead promote autophagy and prevent overfeeding in light of endogenous energy production.However,the optimal energy target during this period is unclear and full starvation is unlikely to be beneficial.There are limited data regarding the effects of prolonged underfeeding on clinical outcomes in critically ill patients,but recent studies show that oral food intake is suboptimal both in the ICU and following discharge to the acute care setting.It is hypothesized that provision of full nutrition(70–100%of EE)may be important in the recovery phase of critical illness(>7 days of ICU admission)for promoting recovery and rehabilitation;however,studies on nutritional intervention delivered from ICU admission through hospital discharge are needed.The aim of this review is to provide a narrative synthesis of the existing literature on metabolic alterations experienced during critical illness and the impact of underfeeding on clinical outcomes in the critically ill adult patient.

Ventilation practices in burn patients—an international prospective observational cohort study

Background:It is unknown whether lung-protective ventilation is applied in burn patients and whether they benefit from it.This study aimed to determine ventilation practices in burn intensive care units(ICUs)and investigate the association between lung-protective ventilation and the number of ventilator-free days and alive at day 28(VFD-28).Methods:This is an international prospective observational cohort study including adult burn patients requiring mechanical ventilation.Low tidal volume(V_(T))was defined as V_(T)≤8 mL/kg predicted body weight(PBW).Levels of positive end-expiratory pressure(PEEP)and maximum airway pressures were collected.The association between V_(T) and VFD-28 was analyzed using a competing risk model.Ventilation settings were presented for all patients,focusing on the first day of ventilation.We also compared ventilation settings between patients with and without inhalation trauma.Results:A total of 160 patients from 28 ICUs in 16 countries were included.Low V_(T) was used in 74%of patients,median V_(T) size was 7.3[interquartile range(IQR)6.2–8.3]mL/kg PBW and did not differ between patients with and without inhalation trauma(p=0.58).Median VFD-28 was 17(IQR 0–26),without a difference between ventilation with low or high V_(T)(p=0.98).All patients were ventilated with PEEP levels≥5 cmH_(2)O;80%of patients had maximum airway pressures<30 cmH_(2)O.Conclusion:In this international cohort study we found that lung-protective ventilation is used in the majority of burn patients,irrespective of the presence of inhalation trauma.Use of low V_(T) was not associated with a reduction in VFD-28.Trial registration:Clinicaltrials.gov NCT02312869.Date of registration:9 December 2014.