No, the glycaemic target in the critically ill should not be < or = 6.1 mmol/l

Continuous renal replacement therapy: a potential source of calories in the critically ill

Background: Overfeeding can lead to multiple metabolic and clinical complications and has been associated with increased mortality in the critically ill. Continuous venovenous hemofiltration (CVVH) represents a potential source of calories that is poorly recognized and may contribute to overfeeding complications.Objective: We aimed to quantify the systemic caloric contribution of acid-citrate-dextrose regional anticoagulation and dextrose-containing replacement fluids in the CVVH circuit.Design: This was a prospective study in 10 critically ill adult patients who received CVVH from April 2014 to June 2014. Serial pre- and postfilter blood samples (n = 4 each) were drawn and analyzed for glucose and citrate concentrations on each of 2 consecutive days.Results: Participants included 5 men and 5 women with a mean ± SEM age of 61 ± 4 y (range: 42-84 y) and body mass index (in kg/m²) of 28 ± 2 (range: 18.3-36.2). There was generally good agreement between data on the 2 study days (CV: 7-11%). Mean ± SEM pre- and postfilter venous plasma glucose concentrations in the aggregate group were 152 ± 10 and 178 ± 9 mg/dL, respectively. Net glucose uptake from the CVVH circuit was 54 ± 5 mg/min and provided 295 ± 28 kcal/d. Prefilter plasma glucose concentrations were higher in patients with diabetes (n = 5) than in those without diabetes (168 ± 12 compared with 140 ± 14 mg/dL; P < 0.05); however, net glucose uptake was similar (46 ± 8 compared with 61 ± 6 mg/min; P = 0.15). Mean ± SEM pre- and postfilter venous plasma citrate concentrations were 1 ± 0.1 and 3.1 ± 0.2 mmol/L, respectively. Net citrate uptake from the CVVH circuit was 60 ± 2 mg/min and provided 218 ± 8 kcal/d.Conclusions: During CVVH there was a substantial net uptake of both glucose and citrate that delivered exogenous energy and provided ∼512 kcal/d. Failure to account for this source of calories in critically ill patients receiving nutrition on CVVH may result in overfeeding.

Review: Does hypoglycaemia cause cardiovascular events?

Strict glycaemic control is strongly advocated in people with type 2 diabetes to prevent vascular disease. However, the outcomes of two large clinical trials have indicated the potential dangers of pursuing this policy in those at high risk of cardiovascular disease, with an excess of fatal vascular events being associated with a higher frequency of severe hypoglycaemia. Hypoglycaemia secondary to insulin and sulphonylurea therapy is often associated with serious morbidity; anecdotal evidence has long implicated hypoglycaemia as a potential cause of myocardial ischaemia or a cardiac arrhythmia. Hypoglycaemia provokes sympatho-adrenal activation and counterregulatory hormone secretion, which exert pronounced cardiovascular effects. Although well tolerated in healthy people, the superimposition of these profound physiological effects on a diseased coronary vasculature and a dysfunctional cardiac conductive system may induce serious or even fatal cardiovascular events. These risks should influence therapeutic targets and the approach to diabetes management in people with diabetes with established vascular disease in whom exposure to severe hypoglycaemia could be dangerous.

Current world literature

This bibliography is compiled by clinicians from the journals listed at the end of this publication. It is based on literature entered into our database between 1 February 2008 and 31 January 2009 (articles are generally added to the database about two and a half months after publication). In addition, the bibliography contains every paper annotated by reviewers; these references were obtained from a variety of bibliographic databases and published between the beginning of the review period and the time of going to press. The bibliography has been grouped into topics that relate to the reviews in this issue.