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STUDY OBJECTIVE: The three-dimensional shape of the ultrasound beam produces a thicker scan plane than most users assume. Viewed longitudinally, a needle placed lateral to a vessel just outside the central scanning plane can be displayed incorrectly in the ultrasound image as if placed intravascularly. This phenomenon is called the beam width artefact, also known as the elevation or slice thickness artefact. The goal of this study was to demonstrate the potential negative effect of the beam width artefact on the performance of in-plane ultrasound-guided vascular access procedures, and to provide a solution.DESIGN: Randomized, double-blinded study SETTING: Department of anaesthesiology and intensive care of a teaching hospital PARTICIPANTS: 31 experienced (anesthesiologists and intensivists) and 36 inexperienced (anesthetic nurses) ultrasound users INTERVENTIONS: We developed an acoustic lens that narrows the scan plane to reduce the beam width artefact. The lens was tested in a simulated vascular access study.MEASUREMENTS: The primary endpoint was first pass success. Secondary endpoints were the number of punctures and needle withdrawals, procedure time, needle visibility and operator satisfaction.MAIN RESULTS: First pass success was highly enhanced using the acoustic lens, with a success rate of 92.5% versus 68.7% without the lens (difference 23.8, 95% confidence interval 11.0-35.3, p < 0.001). The total number of punctures needed to obtain intravenous access was also reduced using the lens (1.10 versus 1.38, difference 0.27, 95% CI 0.11-0.43, p = 0.002). Procedure time, needle withdrawals, needle visibility and satisfaction were similar. Both inexperienced and experienced users benefited from the acoustic lens.CONCLUSIONS: The beam width artefact has a significant effect on the performance of ultrasound-guided needle-based procedures. The efficacy of in-plane superficial vascular access procedures can be enhanced by narrowing the imaging plane using an acoustic lens.

OBJECTIVES:Paediatric patients receive less procedural sedation and analgesia (PSA) in the emergency department compared with adults, especially in countries where emergency medicine is at an early stage of development. The objectives of this study were to evaluate the adverse events and efficacy of paediatric PSA in a country with a recent establishment of emergency medicine and to describe which factors aided implementation.METHODS:This is a prospective, multicentre, observational study of paediatric patients undergoing PSA by the first trained emergency physicians (EPs) in The Netherlands. A standardized data collection form was used at all participating hospitals to collect data on adverse events, amnesia, pain scores, and procedure completion. A survey was used to interpret which factors had aided PSA implementation.RESULTS:We recorded 351 paediatric PSA. The mean age was 9.5 years (95% confidence interval: 9.1-10.0). Esketamine was most frequently used (42.4%), followed by propofol (34.7%). The adverse event rate was low (3.0%). Amnesia was present in 86.8%. The median pain score was 2 (out of 10) for patients without amnesia. Procedures were successfully completed in 93.9% of the cases.CONCLUSION:Paediatric PSA provided by the first EPs in The Netherlands showed appropriate levels of sedation and analgesia with a high rate of procedure completion and a low rate of adverse events. Our paper suggests that EPs provided with a proper infrastructure of mentorship, training and guidelines can implement effective paediatric PSA.

Objective: To describe our experience performing ED procedural sedation in a country where emergency medicine (EM) is a relatively new specialty. Methods: This is a prospective observational study of adult patients undergoing procedural sedation by emergency physicians (EPs) or EM residents in eight hospitals in the Netherlands. Data were collected on a standardised form, including patient characteristics, sedative and analgesic used, procedural success, adverse events (classified according to World SIVA) and rescue interventions. Results: 1711 adult cases were included from 2006 to 2013. Propofol, midazolam and esketamine (S+ enantiomer of ketamine) were the most used sedatives (63%, 29% and 8%). We had adverse event data on all patients. The overall adverse event rate was 11%, mostly hypoxia or apnoea. There was no difference in adverse event rate between EPs and EM residents. However, there was a significantly higher success rate of the procedure when EPs did the procedural sedation (92% vs 84%). No moderate (unplanned hospital admission or escalation of care) or sentinel SIVA outcomes occurred ( pulmonary aspiration syndrome, death or permanent neurological deficit). Conclusion: Adverse events during procedural sedation occurred in 11% of patients. There were no moderate or sentinel outcomes. All events could be managed by the sedating physician. In a country where EM is a relatively new specialty, procedural sedation appears to be safe when performed by EPs or trained EM residents and has comparable adverse event rates to international studies.

OBJECTIVE: The optimal use of pulsed wave Doppler tissue imaging (DTI) in predicting left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) was investigated. METHODS: DTI was performed in 69 patients before and 3 months after CRT. Echocardiographic reverse remodeling was observed in 38 patients. LV dyssynchrony was measured with the time to onset or peak systolic velocity in 2- and 6-basal segment models. RESULTS: The time to onset and either the standard deviation of 6 segments of > 20 ms or a delay of > or = 60 ms between any 2 of 6 segments had a similar predictive accuracy (sensitivity, 97% and 95%, respectively; specificity, 74% and 73%, respectively). The time to peak systolic velocity or evaluating 2 segments was less accurate. CONCLUSIONS: Evaluation of 6 segments is necessary to predict LV reverse remodeling after CRT. The time to onset of systolic velocity is superior to the time to peak velocity.