Anaesthesia
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Randomized Controlled Trial Comparative Study
A randomised, single-blind technical study comparing the ultrasonic visibility of smooth-surfaced and textured needles in a soft embalmed cadaver model.
Visibility of the needle tip and shaft is important during ultrasound-guided regional anaesthesia in order to prevent nerve trauma. Tip and shaft visibility is reduced when needles are inserted in-plane at wide angles and out-of-plane at narrow angles to the ultrasound probe. Although textured needles are more reflective than smooth needles, we hypothesised that poor visibility of the tip and shaft still remained using the above angle-probe combinations. ⋯ The median (IQR [range]) proportions of visible needle tips were 83% (67-83 [50-100]%) for the textured Tuohy, 75% (67-83 [33-83]%) for the textured single-shot needle and 33% (33-46 [0-50]%) for the smooth-surfaced Tuohy (p = 0.0007). Median (IQR [range]) needle shaft visibility was rated as 4.0 (3.5-4.7 [3.0-4.9]) for the textured Tuohy, 4.0 (3.8-4.5 [2.7-4.9]) for the textured single-shot needle and 3.0 (2.4-3.3 [2.3-3.5]) for the smooth-surfaced Tuohy (p = 0.015). Nevertheless, visibility was reduced at wide angles in-plane and narrow angles out-of-plane both for needle tips (p = 0.004) and shafts (p = 0.005).
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Ischaemic heart disease remains the leading cause of death worldwide. Novel approaches to improve morbidity and mortality in this population are essential. Cardiac ischaemic postconditioning - the technique of applying alternating cycles of sublethal myocardial ischaemia and reperfusion after a sustained insult - is one cardioprotective strategy that can reduce reperfusion injury. ⋯ Furthermore, confounders such age, sex and medication, as well as a plethora of co-morbidities common in patients with ischaemic heart disease, all impact on the efficacy of postconditioning. This fragility requires the security of outcomes from large-scale human trials to ensure robust applicability to everyday clinical practice, and to provide assurance of an impact on long-term clinical outcome. This review highlights the development of current postconditioning algorithms, the findings from current proof-of-concept trials, and the barriers that may limit its broad uptake into clinical practice.
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Randomized Controlled Trial
Effective local anaesthetic volumes for sciatic nerve blockade: a clinical evaluation of the ED99.
Previous results in volunteers have indicated the effective dose in 99% of subjects (ED99 ) of local anaesthetic volume to be 0.10 ml.mm(-2) of cross-sectional nerve area for sciatic nerve blockade. The objective of this prospective, randomised, double-blind study was to investigate the ED99 of local anaesthetic for ultrasound-guided sciatic nerve blockade in patients undergoing foot surgery, according to Dixon's up-and-down method and probit analysis. ⋯ Thereafter, the volume of local anaesthetic was increased by 0.02 ml.mm(-2). The ED99 volume of local anaesthetic for ultrasound-guided sciatic nerve blockade was calculated to be 0.15 ml.mm(-2) cross-sectional nerve area, which is higher than the previously evaluated ED99 volume in volunteers.
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Randomized Controlled Trial
A randomised controlled trial of periconal eye blockade with or without ultrasound guidance.
We randomly allocated 129 participants with normal eyes to periconal blockade with (n = 69) or without (n = 60) ultrasound guidance before cataract surgery. There was no difference in the rates of complication, 1/69 and 0/60, respectively, p = 1.0. The rate of intraconal needle placement was 1/69 with ultrasound and 12/60 without ultrasound, a relative risk (95% CI) of 0.07 (0.01-0.55), p < 0.0001.
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Randomized Controlled Trial
Haemoconcentration of residual cardiopulmonary bypass blood using Hemosep(®) : a randomised controlled trial.
Cardiac surgery and cardiopulmonary bypass are associated with haemodilution, activation of haemostasis and blood transfusion. We undertook a randomised controlled trial that included 53 patients in order to compare autotransfusion of residual cardiopulmonary bypass blood with residual blood concentrated using the novel Hemosep(®) device. There was no difference in patients' mean (SD) haemoglobin concentration after autotransfusion of unprocessed blood compared with Hemosep; 103.5 (10.2) g.l(-1) vs 106.2 (12.4) g.l(-1), respectively, p = 0.40. ⋯ This was despite Hemosep's reducing the weight of the blood from a mean (SD) of 778.7 (243.0) g to 607.3 (248.2) g, p < 0.001. The haemoglobin concentration in the processed blood increased from a mean (SD) of 87.0 (15.1) g.l(-1) to 103.7 (17.4) g.l(-1), p < 0.001. We conclude that Hemosep is capable of haemoconcentration when employed to process residual cardiopulmonary bypass blood, but that this is insufficient to increase patient haemoglobin.