Anaesthesia
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Randomized Controlled Trial Comparative Study
Ultrasound-guided catheterisation of the subclavian vein: freehand vs needle-guided technique.
The objective of this prospective, randomised study was to examine the impact of a multi-angle needle guide for ultrasound-guided, in-plane, central venous catheter placement in the subclavian vein. One hundred and sixty patients were randomly allocated to two groups, freehand or needle-guided, and then 159 catheterisations were analysed. Cannulation of the first examined access site was successful in 96.9% of cases with no significant difference between groups. ⋯ Use of the needle guide reduced the access time from a median (IQR [range]) of 30 (18-76 [6-1409]) s to 16 (10-30 [4-295]) s; p = 0.0001, and increased needle visibility from 31.8% (9.7%-52.2% [0-96.67]) to 86.2% (62.5%-100% [0-100]); p < 0.0001. A multi-angle needle guide significantly improved aligning the needle and ultrasound plane compared with the freehand technique when cannulating the subclavian vein. Use of the guide resulted in faster access times and increased success at the first and second attempts.
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During and after cardiac surgery with cardiopulmonary bypass, high concentrations of oxygen are routinely administered, with the intention of preventing cellular hypoxia. We systematically reviewed the literature addressing the effects of arterial hyperoxia. Extensive evidence from pre-clinical experiments and clinical studies in other patient groups suggests predominant harm, caused by oxidative stress, vasoconstriction, perfusion heterogeneity and myocardial injury. ⋯ Current evidence is insufficient to specify optimal oxygen targets. Nevertheless, the safety of supraphysiological oxygen suppletion is unproven. Randomised studies with a variety of oxygen targets and inclusion of high-risk patients are needed to identify optimal oxygen targets during and after cardiac surgery.
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Controlled Clinical Trial
Accuracy of conventional digital palpation and ultrasound of the cricothyroid membrane in obese women in labour.
Success of cricothyroidotomy depends on accurate identification of anatomical neck landmarks. Anaesthetists palpated the cricothyroid membrane of 28 obese and 28 non-obese women in labour (cut-off BMI 30 kg.m(-2) ) and marked the entry point for device insertion with an ultraviolet invisible pen. Ultrasonography was used to mark the midpoint of the cricothyroid membrane and the distance between the two marks was measured. ⋯ Increased neck circumference in obese patients was significantly associated with inaccuracy in locating the cricothyroid membrane. Percutaneous identification of the cricothyroid membrane in obese women in labour was poor. Pre-procedural ultrasound may help improved the identification of neck landmarks for cricothyroidotomy.