Anaesthesia and intensive care
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Anaesth Intensive Care · Mar 2019
Conservative versus conventional oxygen therapy for cardiac surgical patients: A before-and-after study.
Avoiding hypoxaemia is considered crucial in cardiac surgery patients admitted to the intensive care unit (ICU). However, avoiding hyperoxaemia may also be important. A conservative approach to oxygen therapy may reduce exposure to hyperoxaemia without increasing the risk of hypoxaemia. ⋯ Moreover, more ABG samples were hyperoxaemic or severely hyperoxaemic during conventional treatment ( P < 0.001). Finally, there was no difference in ICU or hospital length of stay, ICU or hospital mortality or 30-day mortality between the groups. Our findings support the feasibility and physiological safety of conservative oxygen therapy in patients admitted to ICU after cardiac surgery.
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Anaesth Intensive Care · Mar 2019
Observational StudyCan the blood gas analyser results be believed? A prospective multicentre study comparing haemoglobin, sodium and potassium measurements by blood gas analysers and laboratory auto-analysers.
Blood gas analysers are point-of-care testing devices used in the management of critically ill patients. Controversy remains over the agreement between the results obtained from blood gas analysers and laboratory auto-analysers for haematological and biochemistry parameters. We conducted a prospective analytical observational study in five intensive care units in Western Australia, in patients who had a full blood count (FBC), urea, electrolytes and creatinine (UEC), and a blood gas performed within 1 h of each other during the first 24 h of their intensive care unit admission. ⋯ There was no statistically significant difference between the results of the blood gas and laboratory auto-analysers for haemoglobin (mean difference -0.35 g/L, 95% confidence interval (CI) -1.20 to 0.51, P = 0.425). Although the mean differences between the two methods were statistically significant for sodium (mean difference 1.49 mmol/L, 95% CI 1.23-1.76, P < 0.0001) and potassium (mean difference 0.19 mmol/L, 95% CI 0.15-0.24, P < 0.0001), the mean biases on the Bland-Altman plots were small and independent of the magnitude of the measurements. The two methods of measurement for haemoglobin, sodium and potassium agreed with each other under most clinical situations when their values were within or close to normal range suggesting that routine concurrent blood gas and formal laboratory testing for haemoglobin, sodium and potassium concentrations in the intensive care unit is unwarranted.
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Anaesth Intensive Care · Mar 2019
Randomized Controlled TrialComparison of the EasyWarm® self-heating blanket with the Cocoon forced-air warming blanket in preventing intraoperative hypothermia.
The importance of preventing hypothermia in the perioperative period cannot be overemphasised. The use of active warming devices is advocated and practised widely. The forced-air warming (FAW) blanket is currently a popular modality. ⋯ Similarly, the difference between average temperatures at 1, 2 and 3 h was not statistically significant. We found the EasyWarm® blanket to be as effective as the Cocoon FAW blanket in preventing intraoperative hypothermia. Due to its ease of use, the EasyWarm® blanket may have an additional benefit in preoperative warming of patients.
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Anaesth Intensive Care · Mar 2019
Randomized Controlled TrialAdding low concentrations of clonidine to ropivacaine for transversus abdominis plane blocks does not reduce plasma ropivacaine levels, suggesting a lack of vasoconstrictor effect.
Clonidine has been used successfully to prolong the duration of action of local anaesthetics in peripheral nerve blocks, but its mechanism of action in this setting remains unclear. Some studies suggest that clonidine exerts a vasoconstrictor effect, limiting the washout of local anaesthetic from its site of deposition. We investigated this potential vasoconstrictor effect, using plasma ropivacaine concentrations as a surrogate measure of vasoconstriction, in patients who received transversus abdominis plane (TAP) blocks with and without clonidine. ⋯ These findings indicate that clonidine at a concentration of 1.35 μg/mL added to ropivacaine for TAP blocks did not produce a reduction in plasma ropivacaine concentrations. This suggests a lack of vasoconstrictor effect during TAP blocks. Further studies should evaluate whether vasoconstriction occurs when clonidine is used at higher concentrations or for other blocks.