Anaesthesia and intensive care
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Anaesth Intensive Care · May 2024
The influence of needleless connectors and inserted catheters on flow rates through vascular introducer sheaths.
SummaryA vascular introducer sheath is often used for rapid volume replacement. However, common manipulations such as the addition of needleless connectors to infusion ports and the insertion of catheters or other devices through the introducer sheath may impede flow. In this study we utilised a rapid infuser to deliver room-temperature normal saline through two introducer sheath configurations with and without the addition of needleless connectors and the placement of catheters through the introducer sheaths. ⋯ These findings indicated that both needleless connectors and the placement of catheters through vascular introducer sheaths substantially reduced potential flow rates. Even 'large' vascular introducer sheaths capable of delivering high flow rates could be rendered minimally effective for rapid fluid administration when used in this way. Clinicians should consider these impediments to flow when rapid fluid administration is required, and obtain alternative vascular access if necessary.
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Anaesth Intensive Care · Mar 2024
Observational StudyObservational study of the effect of ketamine infusions on sedation depth, inflammation, and clinical outcomes in mechanically ventilated patients with SARS-CoV-2.
Severely ill patients with COVID-19 are challenging to sedate and often require high-dose sedation and analgesic regimens. Ketamine can be an effective adjunct to facilitate sedation of critically ill patients but its effects on sedation level and inflammation in COVID-19 patients have not been studied. This retrospective, observational cohort study evaluated the effect of ketamine infusions on inflammatory biomarkers and clinical outcomes in mechanically ventilated patients with SARS-CoV-2 infection. ⋯ Regarding inflammatory biomarkers, ketamine was associated with a reduction in ferritin (P = 0.02) and lactate (P = 0.01), but no such association was observed for C-reactive protein (P = 0.27), lactate dehydrogenase (P = 0.64) or interleukin-6 (P = 0.87). No significant association was observed between ketamine administration and mortality (odds ratio 0.971; 95% confidence interval 0.501 to 1.882; P = 0.93). Ketamine infusion was associated with improved sedation depth in mechanically ventilated COVID-19 patients and provided a modest anti-inflammatory benefit but did not confer benefit with respect to mortality or intensive care unit length of stay.
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Anaesth Intensive Care · Mar 2024
A weighing method for measuring nitrous oxide leakage from hospital manifold-pipeline networks.
Nitrous oxide is a potent greenhouse gas and ozone-depleting agent with a long atmospheric lifetime. Several previous reports indicate that over half of supplied nitrous oxide is wasted from leaking manifold-pipeline systems infrastructure prior to patient use, and that remediating leaks can have significant environmental benefits. We describe an accurate, simple and cost-effective cylinder weighing method to quantify nitrous oxide leak from the manifold-pipeline network at our tertiary non-obstetric facility. ⋯ This was only 16.5% of actual cylinder depletion (11,686 l; 21.88 kg), indicating that 83.5% (9754 l; 18.26 kg) of nitrous oxide had leaked to the atmosphere (376 ml/minute; 22.6 l/hour; 542 l/day). The fraction of nitrous oxide wasted was consistent with a retrospective analysis of the previous 2-year period at the site that compared purchasing records with estimated clinical use. If maintained over a year, the leak would be equivalent to 101 tonnes of carbon dioxide per annum.