Towards net zero: critical care

Blood gas sampling in the intensive care unit: A prospective before-and-after interventional study on the effect of an educational program on blood gas testing frequency

BACKGROUND

Blood gas analysis is the most commonly ordered test in the intensive care unit. Each investigation, however, comes with risks and costs to the patient and healthcare system. Evidence suggests that many tests are performed with no appropriate clinical indication.

OBJECTIVES

The primary aim of our prospective interventional study was to investigate the proportion of blood gases undertaken with a valid clinical indication before and after an educational intervention. A secondary aim was to examine sleep interruption secondary to blood gas sampling.

METHODS

A prospective, before-and-after interventional study was conducted across two metropolitan intensive care units in Melbourne, Australia. Adults aged ≥18 years who were admitted to intensive care were eligible for inclusion. Two observation periods were conducted across a 2-week period in May and September 2022 (Periods 1 and 2), where clinicians were encouraged to record the purpose of blood gas sampling and other relevant data via an electronic questionnaire. These data were reviewed with corresponding electronic medical records. In between these periods, an interventional educational program to inform the clinical rationale for blood gas testing was delivered during July and August 2022, including introduction of a clinical guideline.

RESULTS

There were 68 patients with 688 tests included in Period 1 compared to 69 patients with 756 tests in Period 2. There was no significant difference between the median number of blood gas analyses performed per patient before and after the educational intervention (6.0 tests per patient vs 5.0 tests per patient, p = 0.609). However, there was a significant increase in the percentage of tests with a valid clinical indication (49.0% vs 59.7%, p = 0.0025). The most common indications selected were routine measurement, monitoring a clinical value, change in ventilator settings/oxygen therapy, and clinical deterioration. In addition, there were a large number of patients who were awakened upon drawing of a blood sample for analysis (26.1% for Period 1 and 37.6% for Period 2, p = 0.06).

CONCLUSION

The implementation of an educational program resulted in a significant increase in the proportion of blood gases performed with an appropriate clinical indication. There was, however, no reduction in the overall number of blood gases performed.

Past, present, and future of sustainable intensive care: narrative review and a large hospital system experience

Healthcare systems are large contributors to global emissions, and intensive care units (ICUs) are a complex and resource-intensive component of these systems. Recent global movements in sustainability initiatives, led mostly by Europe and Oceania, have tried to mitigate ICUs' notable environmental impact with varying success. However, there exists a significant gap in the U.S. knowledge and published literature related to sustainability in the ICU. After a narrative review of the literature and related industry standards, we share our experience with a Green ICU initiative at a large hospital system in Texas. Our process has led to a 3-step pathway to inform similar initiatives for sustainable (green) critical care. This pathway involves (1) establishing a baseline by quantifying the status quo carbon footprint of the affected ICU as well as the cumulative footprint of all the ICUs in the healthcare system; (2) forming alliances and partnerships to target each major source of these pollutants and implement specific intervention programs that reduce the ICU-related greenhouse gas emissions and solid waste; and (3) finally to implement a systemwide Green ICU which requires the creation of multiple parallel pathways that marshal the resources at the grass-roots level to engage the ICU staff and institutionalize a mindset that recognizes and respects the impact of ICU functions on our environment. It is expected that such a systems-based multi-stakeholder approach would pave the way for improved sustainability in critical care.

The carbon footprint of different modes of birth in the UK and the Netherlands: An exploratory study using life cycle assessment

OBJECTIVE

To compare the carbon footprint of caesarean and vaginal birth.

DESIGN

Life cycle assessment (LCA).

SETTING

Tertiary maternity units and home births in the UK and the Netherlands.

POPULATION

Birthing women.

METHODS

A cradle-to-grave LCA using openLCA software to model the carbon footprint of different modes of delivery in the UK and the Netherlands.

MAIN OUTCOME MEASURES

'Carbon footprint' (in kgCO2 equivalents [kgCO2 e]).

RESULTS

Excluding analgesia, the carbon footprint of a caesarean birth in the UK was 31.21 kgCO2 e, compared with 12.47 kgCO2 e for vaginal birth in hospital and 7.63 kgCO2 e at home. In the Netherlands the carbon footprint of a caesarean was higher (32.96 kgCO2 e), but lower for vaginal birth in hospital and home (10.74 and 6.27 kgCO2 e, respectively). Emissions associated with analgesia for vaginal birth ranged from 0.08 kgCO2 e (with opioid analgesia) to 237.33 kgCO2 e (nitrous oxide with oxygen). Differences in analgesia use resulted in a lower average carbon footprint for vaginal birth in the Netherlands than the UK (11.64 versus 193.26 kgCO2 e).

CONCLUSION

The carbon footprint of a caesarean is higher than for a vaginal birth if analgesia is excluded, but this is very sensitive to the analgesia used; use of nitrous oxide with oxygen multiplies the carbon footprint of vaginal birth 25-fold. Alternative methods of pain relief or nitrous oxide destruction systems would lead to a substantial improvement in carbon footprint. Although clinical need and maternal choice are paramount, protocols should consider the environmental impact of different choices.