Anaesthesia and intensive care
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Anaesth Intensive Care · Nov 2016
Accuracy of dispersing tramadol capsules for oral administration in young children.
Tramadol is used in children aged <12 years for analgesia, particularly for those at risk of obstructive sleep apnoea undergoing adenotonsillectomy. The Australian Therapeutic Goods Administration have strongly recommended that oral tramadol drops (100 mg/ml) not be used in children <12 years because of the risk of inadvertent overdose. The total mass of drug in a 10 ml bottle is 1000 mg. ⋯ Despite the dose variability of this method of preparing tramadol, we consider it sufficiently accurate for clinical use. We also consider it safe, as even at the highest dose prepared, the variability would be unlikely to contribute to clinically significant side-effects or toxicity. Moreover, the maximal dose that could be administered is limited to the size of the capsule (50 mg).
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Anaesth Intensive Care · Nov 2016
Sequencing of genes involved in the movement of calcium across human skeletal muscle sarcoplasmic reticulum: continuing the search for genes associated with malignant hyperthermia.
The genetic basis of malignant hyperthermia (MH) is not fully characterised and likely involves more than just the currently classified mutations in the gene encoding the skeletal muscle ryanodine receptor (RYR1) and the gene encoding the α1 subunit of the dihydropyridine receptor (CACNA1S). In this paper we sequence other genes involved in calcium trafficking within skeletal muscle in patients with positive in vitro contracture tests, searching for alternative genes associated with MH. ⋯ These four variants have very low minor allele frequencies and while it is tempting to speculate that they have a role in MH, they remain at present variants of unknown significance. Nevertheless they provide the basis for a new set of functional studies, which may indeed identify novel players in MH.
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Anaesth Intensive Care · Nov 2016
The effect of dabigatran on the kaolin-activated whole blood thromboelastogram.
Dabigatran is a direct thrombin inhibitor, which is increasingly likely to be encountered in patients presenting for surgery. This study examines whether there is a consistent effect of dabigatran on the thromboelastogram (TEG) and whether this correlates with the effects of dabigatran on traditional coagulation parameters. ⋯ Despite the moderate to high correlation between the TEG R-time and the TCT and APTT, there appeared to be no consistent effect of dabigatran on the TEG. These findings suggest that use of kaolin-activated whole blood TEG does not add additional benefit to traditional coagulation tests when monitoring the effect of dabigatran.
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Anaesth Intensive Care · Nov 2016
Balancing the risks and benefits of using emergency diagnostic radiocontrast studies to diagnose life-threatening illness in critically ill patients: a decision analysis.
Diagnosis of many life-threatening illnesses, including acute pulmonary embolism, aortic dissection, and ischaemic bowel disease, requires confirmatory radiological imaging with radiocontrast. It is well established that radiocontrast can induce acute kidney injury, especially in patients with pre-existing renal impairment. The decision to proceed with a radiological study with radiocontrast to confirm or exclude a life-threatening, but potentially reversible, illness in patients with renal impairment is difficult. ⋯ In critically ill patients presenting with a life-threatening illness with hypotension requiring vasopressors or inotropes, the risk of CIN (defined by an increment in plasma creatinine of 40 µmol/l) and the associated attributable mortality after using 50 to 100 ml of radiocontrast was about 30% and 4%, respectively, for patients with baseline plasma creatinine concentrations <400 µmol/l. The risk of CIN and its associated attributable mortality increased substantially and exceeded 80% and 10%, respectively, if patients also had diabetes mellitus and their baseline plasma creatinine concentrations were >400 µmol/l. In the latter high-risk patients, using a radiocontrast study to diagnose or exclude a life-threatening illness could only be justified if the life-threatening illness was readily treatable and the pre-test probability of having such disease was greater than 15%-20%.
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Anaesth Intensive Care · Nov 2016
Defining a reference range for vital signs in healthy term pregnant women undergoing caesarean section.
Early warning systems (EWS), used to identify deteriorating hospitalised patients, are based on measurement of vital signs. When the patients are pregnant, most EWS still use non-pregnant reference ranges of vital signs to determine trigger thresholds. There are no published reference ranges for all vital signs in pregnancy. ⋯ This study defined a reference range for vital signs in healthy term pregnant women undergoing CS. Study findings suggest that currently used criteria for EWS triggers, based on non-pregnant values, may be too extreme for timely detection of deteriorating pregnant patients. Further research examining the modified HR triggers of ≤50 and ≥110 /minute in pregnant women and their relationship to clinical outcomes is required.