The carbon footprint of acute care: how energy intensive is critical care?

OBJECTIVES: Climate change has the potential to threaten human health and the environment. Managers in healthcare systems face significant challenges to balance carbon mitigation targets with operational decisions about patient care. Critical care units are major users of energy and hence more evidence is needed on their carbon footprint. STUDY DESIGN: The authors explore a methodology which estimates electricity use and associated carbon emissions within a Critical Care Unit (CCU). METHODS: A bottom-up model was developed and calibrated which predicted the electricity consumed and carbon emissions within a CCU based on the type of patients treated and working practices in a case study in Cornwall, UK. RESULTS: The model developed was able to predict the electricity consumed within CCU with an error of 1% when measured against actual meter readings. Just under half the electricity within CCU was used for delivering care to patients and monitoring their condition. CONCLUSIONS: A model was developed which accurately predicted the electricity consumed within a CCU based on patient types, medical devices used and working practice. The model could be adapted to enable it to be used within hospitals as part of their planning to meet carbon reduction targets.

Psychological outcomes in critically ill patients receiving renal replacement therapy: a matched-pairs analysis.

We conducted a single-centre observational study over five years to assess the impact of renal replacement therapy on the psychological health of survivors of critical illness. We hypothesised that the added burden of renal replacement would increase the prevalence and severity of anxiety, depression and stress reactions in these patients, compared with matched pairs (matched for age, sex and APACHE II score) who did not receive renal replacement. Participants completed postal questionnaires. A total of 342 patients with acute kidney injury received renal replacement. One hundred and seventy-nine (52.3%) survived to hospital discharge, and 161 (47.1%) were alive at 90 days. Seventy-seven (47.8% of survivors) completed questionnaires. We found 77 matches for the Hospital Anxiety and Depression Scale analysis and 72 for the Impact of Events Scale analysis. Clinically relevant symptoms of psychiatric morbidity were common, with anxiety and depression affecting 49 (63.6%) patients and stress reactions affecting 24 (33.3%) patients. Mean scores (95% CI) were 11.4 (9.6-13.2) and 20.1 (15.7-24.6), respectively. On multivariate analysis, we found no significant differences between renal replacement patients and controls, in either the frequency or severity of these symptoms.

Changing practice with changing research: results of two UK national surveys of intensive insulin therapy in intensive care patients.

We conducted two telephone surveys of all United Kingdom adult intensive care units in 2007/8 and 2010 to assess practice with regard to intensive insulin therapy for glycaemic control in critically ill patients, and to assess the change in practice following publications in 2008 and 2009 that challenged the evidence for this therapy. Of 243 units that had a written policy for intensive insulin therapy in 2007/8, 232 (96%) still had a policy in 2010. One hundred and six (46%) units had updated their policy in response to new evidence, whereas 126 (54%) stated that it had remained the same. Where intensive care units had changed their policy, we found a significant increase in target limits and a wider target range. Regional variations in practice were also seen. Across seven regions, the percentage of units where the glycaemic control policy had been updated since 2007/8 varied from nil to 78.9%.

Evaluation of the Haemoglobin Colour Scale and comparison with the HemoCue haemoglobin assay.

OBJECTIVE: To evaluate the Haemoglobin Colour Scale developed by WHO for estimating haemoglobin concentration and to compare the results obtained using it and the HemoCue assay with those determined using a reference method, the Technicon H3 analyser. METHODS: The Colour Scale and HemoCue assay were used to test 408 blood samples. Subsequently, Bland-Altman plots were determined and the proximity of the test results to those obtained using the reference method was determined. FINDINGS: The mean difference between the Haemoglobin Colour Scale and the reference method was 0.19 g/dl (95% confidence interval: 3.50 g/dl below to 3.11 g/dl above); the corresponding value for the HemoCue assay was 0.50 g/dl (1.16 g/dl below to 0.16 g/dl above). Only 46.08% of the results obtained by means of the Colour Scale were within 1.0 g/dl of the reference method, whereas 95.34% of the HemoCue results fell within this limit; 22.79% of the Colour Scale results but none of the HemoCue results lay more than 2.0 g/dl from the reference method. CONCLUSION: The Haemoglobin Colour Scale test is too inaccurate for general use, particularly if devices such as the HemoCue are available.