Anaesthesia and intensive care
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Anaesth Intensive Care · Sep 2013
Type 2 diabetes mellitus, independent of insulin use, is associated with an increased risk of cardiac complications after vascular surgery.
Previous reports on the prognostic value of diabetes mellitus for cardiac complications after vascular surgery show divergent results, especially in regards to the role of type 2 diabetes as a cardiac risk factor, which remains unclear. The aim of this study was to assess the impact of type 2 diabetes on 30-day cardiac complications after vascular surgery. Patients undergoing elective vascular surgery between 2002 and 2011 were included in this retrospective cohort study. ⋯ In multivariate analysis, type 2 diabetes was associated with a significantly increased risk of 30-day cardiac complications (odds ratio 1.80; 95% confidence interval 1.25 to 2.60). Results were similar for type 2 diabetes patients managed with (odds ratio 1.84; 95% confidence interval 1.01 to 3.37) and without (odds ratio 1.79; 95% confidence interval 1.19 to 2.70) insulin. Type 2 diabetes is an independent risk factor for cardiac complications after vascular surgery and should be treated as such in preoperative cardiac risk stratification.
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Anaesth Intensive Care · Sep 2013
A preliminary evaluation of plasma b-type natriuretic peptide as a screening test for left ventricular diastolic dysfunction in non-cardiac intensive care.
Left ventricular filling and thus diastolic function are frequently monitored and managed in critical care. However, scant data exist regarding possible screening tests for diastolic dysfunction in the intensive care unit (ICU). The present study aimed to evaluate plasma b-type natriuretic peptide (BNP) as a marker of diastolic dysfunction in a single-centre cohort of 'non-cardiac' ICU patients. ⋯ BNP correlated independently with E/e' (R=0.425; P=0.015) (E/e': peak early transmitral velocity [E]/early diastolic mitral annular velocity [e']) but not left ventricular ejection fraction (P=0.8), illness severity (Acute Physiological and Chronic Health Evaluation II; P=0.3) or fluid balance (P=0.4). Diastolic dysfunction was common in this cohort of non-cardiac ICU patients and was independently associated with a significantly higher BNP. The potential application as a screening test for diastolic dysfunction is likely to require a threshold lower than previously proposed for heart failure.
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Anaesth Intensive Care · Sep 2013
Binding of local anaesthetics to the lipid emulsion Clinoleic™ 20%.
Lipid emulsions have been used to treat cardiovascular collapse due to local anaesthetic toxicity. However, there are few data available on the comparative efficiency of the partitioning properties of available lipid emulsions in clinical use. This in vitro study compared the buffering properties of the lipid emulsions Clinoleic™ 20% (Baxter, Old Toongabbie, NSW) and Intralipid® 20% (Fresenius Kabi, Pymble, NSW) using both bupivacaine (Marcain® 0.5%, AstraZeneca, North Ryde, NSW) and ropivacaine (Naropin® 1%, AstraZeneca, North Ryde, NSW). ⋯ Bupivacaine was more effectively bound by the lipid agents, with a 40% reduction in initial concentration. Ropivacaine demonstrated a 20% reduction in concentration with the addition of lipid agents. Importantly, there was no significant difference between Intralipid and Clinoleic in terms of their buffering behaviour, suggesting equivalent binding efficacy.
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Cricothyroidotomy is infrequently performed in the intensive care unit but may be a lifesaving procedure. The aim of this study was to determine the number of attempts required by trainees to gain adequate skills for a successful cricothyroidotomy (defined as lung inflation <60 seconds). The effect of training on time to completion of cricothyroidotomy was also studied. ⋯ Age, years of postgraduate practice and level of seniority appeared to be associated with earlier success. Consecutive attempts on a manikin led to an improvement in the time to completion of cricothyroidotomy and rate of a successful outcome (<60 seconds). We recommend that clinicians undergo at least five training attempts on a manikin to gain proficiency in cricothyroidotomy.
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Anaesth Intensive Care · Sep 2013
Phenytoin loading doses in adult critical care patients: does current practice achieve adequate drug levels?
Phenytoin is regularly employed in the critically ill for prophylaxis against or treatment of seizure disorders. No prior studies have examined current dosing practices in an Australasian intensive care unit (ICU) setting. The aims of this study were to: a) describe the adequacy of contemporary dosing in respect to free and total serum phenytoin concentrations; b) identify factors associated with therapeutic drug concentrations; and c) examine the accuracy of predictive equations that estimate free concentrations in this setting. ⋯ Twenty-six patients (49%) had suboptimal trough free concentrations, although this subgroup was significantly heavier and therefore received a lower per kilogram dose (12.8 [3.1] vs 16.3 [3.4] mg/kg, P=0.001). In multivariate analysis, larger weight adjusted doses (P=0.018), higher albumin concentration (P=0.034) and receiving phenytoin for an indication other than seizure (P=0.035), were associated with a greater likelihood of adequate concentrations. In conclusion, phenytoin dosing remains complex in critically ill patients, although lower per kilogram loading doses are strongly associated with free concentrations below the desired target.