Publications

info:eu-repo/semantics/published

The determination of oxygen consumption (VO2) in critically ill patients is useful to evaluate metabolic expenditure, to calculate cardiac output and to assess the adequacy of oxygen supply to the tissues by the relationship between oxygen delivery (DO2) and VO2. Only the last application requires a high degree of accuracy in measurement. Highly accurate devices have been developed over the last few years although there are still problems with their use during spontaneous ventilation, mechanical ventilation with high FiO2, and treatment with inhaled nitric oxide (NO). Due to Haldane's transformation and the body's large CO2 stores, VO2 should only be measured in steady-state conditions, avoiding changes in ventilatory conditions or cardiac output. Air leaks should be carefully avoided since measurements would be erroneous. There is generally good agreement between Fick-derived VO2 and VO2 obtained by indirect calorimetry; discrepancies between the two methods in the study of changes in VO2 in response to changes in DO2 could be due to errors in both techniques. There is no strong evidence that mathematical coupling of data alone can account for VO2/DO2 dependency, which can sometimes be observed in critically ill patients.

Type 2 diabetes has reached epidemic proportions in many parts of the world. The disease is projected to continue to increase and double within the foreseeable future. Dysglycaemia develops in the form of hyperglycaemia, hypoglycaemia and marked glucose variability in critically ill adults whether they are known to have premorbid diabetes or not. Patients with such glucose dysregulation have increased morbidity and mortality. Whether this is secondary to cause and effect from dysglycaemia or is just related to critical illness remains under intense investigation. Identification of intensive care unit (ICU) patients with unrecognised diabetes remains a challenge. Further, there are few data regarding the development of type 2 diabetes in survivors after hospital discharge. This commentary introduces the concept of critical illness-induced dysglycaemia as an umbrella term that includes the spectrum of abnormal glucose homeostasis in the ICU. We outline the need for further studies in the area of glucose regulation and for follow-up of the natural history of abnormal glucose control during ICU admission and beyond.

Albumin solutions have been used worldwide for the treatment of critically ill patients since they became commercially available in the 1940s. However, their use has become the subject of criticism and debate in more recent years. Importantly, all fluid solutions have potential benefits and drawbacks. Large multicenter randomized studies have provided valuable data regarding the safety of albumin solutions, and have begun to clarify which groups of patients are most likely to benefit from their use. However, many questions remain related to where exactly albumin fits within our fluid choices. Here, we briefly summarize some of the physiology and history of albumin use in intensive care before offering some evidence-based guidance for albumin use in critically ill patients.

Hemodynamic monitoring plays a fundamental role in the management of acutely ill patients. With increased concerns about the use of invasive techniques, notably the pulmonary artery catheter, to measure cardiac output, recent years have seen an influx of new, less-invasive means of measuring hemodynamic variables, leaving the clinician somewhat bewildered as to which technique, if any, is best and which he/she should use. In this consensus paper, we try to provide some clarification, offering an objective review of the available monitoring systems, including their specific advantages and limitations, and highlighting some key principles underlying hemodynamic monitoring in critically ill patients.