Infraglottic versus supraglottic jet-ventilation for endobronchial ultrasound-guided transbronchial needle aspiration: A randomised controlled trial.

BACKGROUND: For endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) under general anaesthesia, both rigid bronchoscopy and laryngeal masks (LMAs) with superimposed high-frequency jet ventilation can be used. Despite the fact that in Europe rigid bronchoscopy for EBUS-TBNA is still widely used, an increasing number of centres use jet ventilation via the LMA for this procedure. To our knowledge no clinical trials have ever been made to compare these two methods. This trial aimed to evaluate whether patients recover from the procedure more quickly when a LMA is used for ventilation compared with rigid bronchoscopy where muscle relaxants and deep anaesthesia are required. OBJECTIVES: We wanted to test the hypothesis that there is no difference in the postoperative recovery of patients in the postanaesthesia care unit (PACU) after EBUS-TBNA with jet ventilation via a rigid bronchoscope and a LMA. Secondary outcomes were the difference of duration of anaesthesia, the diagnostic outcome of the procedure and drug quantities for both groups. DESIGN: Prospective randomised single blinded two centre controlled trial. SETTING: Two centres in Austria participated. Patients were enrolled from December 2016 until January 2018. PATIENTS: Ninety patients for elective EBUS-TBNA were enrolled and assigned to one of two intervention groups. Two patients were excluded before and eleven patients were excluded after EBUS-TBNA. Seventy-seven were analysed. INTERVENTIONS: Patients assigned to group 1 were ventilated with a LMA; those assigned to group 2 were ventilated via a rigid bronchoscope. Vital signs, drug dosage, duration of anaesthesia, recovery, PACU stay and Aldrete score at the PACU were recorded. MAIN OUTCOME MEASURES: The primary endpoint was an integral over time of a modified Aldrete score. Secondary endpoints were the durations of the interventions, the recovery from anaesthesia and PACU stay, initial and mean Aldrete values at PACU, the effect site concentration of Propofol according to the Schnider pharmacokinetic model, the peak ultiva rates and the diagnostic outcome. RESULTS: We were not able to show any significant difference regarding the postoperative recovery criteria based on the Aldrete score, the durations measured and the diagnostic outcomes. Vital signs remained stable and in an equal range in both groups. There were no differences in the mean effect site propofol concentration and the peak ultiva rates. CONCLUSION: EBUS-TBNA under general anaesthesia using a LMA with SHJV is equal to rigid bronchoscopy with superimposed high-frequency jet ventilation for the variables analysed. TRIAL REGISTRATION: ISRCTN (ISRCTN58911367).

Combining spatial information and optimization for locating emergency medical service stations: A case study for Lower Austria.

OBJECTIVES: Emergency medical services have been established in many countries all over the world. Good first care improves the outcome of patients in terms of hospital stay duration, chances of full recovery and of treatment costs. In this paper, we present an integrated approach combining spatial information and integer optimization for emergency medical service location planning. The research is motivated by a recent call for bids to restructure the location of emergency medical services in the Austrian federal state of Lower Austria by the local state government. METHODS: Our framework allows for constraints on the places where an emergency care physician is stationed, accounting for the fact that - for economical reasons - it might not be feasible to arbitrarily place emergency care physicians. We use maximum coverage linear programs to get accurate solutions for the problem instances (depending on the maximum allowed number of emergency care physicians and the constraints of their placement). We optimize for the maximum number of covered residents given certain parameters. The travelling distances are calculated by means of a digital road graph. Moreover we analyze the coverage of the day population as there are significant shifts in the number of persons present at daytime. For every problem instance we have calculated the ten best solutions and examined the variance among them. For the demand point aggregation we have used a cell grid. RESULTS: Using our method we can show that with less emergency care physicians more residents can be covered. This is highly applicable to low populated areas where the coverage becomes better. There is little variance from the best to the second best solution: There are only small changes (usually only one cell is shifted) between the best and the second best solution. The coverage of the day population - except for a few problem instances - is always better than the coverage of the residents (reflecting the fact that many residents commute to more densely populated areas). CONCLUSIONS: In our study, we show that our solutions provide better coverage of residents with fewer emergency care physicians than the current status quo.