IntroductionVenous sampling for blood gas analysis has been suggested as an alternative to arterial sampling in order to reduce pain. The main objective was to compare pain induced by venous and arterial sampling and to assess whether the type of sampling would affect clinical management or not.MethodsWe performed an open-label randomised multicentre prospective study in four French EDs during a 4-week period. Non-hypoxaemic adults, whose medical management required blood gas analysis, were randomly allocated using a computer-generated randomisation list stratified by centres with an allocation ratio of 1:1 using random blocks to one of the two arms: venous or arterial sampling. The primary outcome was the maximal pain during sampling, using the visual analogue scale. Secondary outcomes pertained to ease of sampling as rated by the nurse drawing the blood, and physician satisfaction regarding usefulness of biochemical data.Results113 patients were included: 55 in the arterial and 58 in the venous sampling group. The mean maximal pain was 40.5 mm±24.9 mm and 22.6 mm±20.2 mm in the arterial group and the venous group, respectively, accounting for a mean difference of 17.9 mm (95% CI 9.6 to 26.3) (p<0.0001). Ease of blood sampling was greater in the venous group as compared with the arterial group (p=0.02). The usefulness of the results, evaluated by the prescriber, did not significantly differ (p=0.25).ConclusionsVenous blood gas is less painful for patients than ABG in non-hypoxaemic patients. Venous blood gas should replace ABG in this setting.Trial registration numberNCT03784664.

Funding Acknowledgements Type of funding sources: None. Introduction Atrial wall perforation is a rare but serious complication of transeptal puncture in AF catheter ablation procedure. In patients with uninterrupted anticoagulation associated to non-fractionated heparin bolus this may lead to cardiac tamponade and dramatic consequences. Urgent surgical drainage and repair is mandatory in the most dramatic cases. We report the successful closure of such complication by an Amplatzer vascular plug leading to a rapid and total recovery in 3 patients. Methods Three patients (male, 43, 77 and 84 yo) referred for persistent atrial fibrillation ablation (1 RF and 2 cryoablations). After transeptal puncture, they became severely hypotensive with echographic evidence of tamponade. Results Heart perforation with massive leakage of contrast in the pericardial space was evident. The perforation was anterior near aorta in one, on the posterior wall of the right atrium in one and on the posterior wall of the left atria though the right atria in one. After heparin antagonization by protamin, the pericardial space was drained percutaneously (1 to 3 l drained and in 1 reinjected through a "cell saver" system). Rapidly, a 0,035 J guide wire was passed through the perforation and an Amplatzer vascular Plug 2 (4 mm in 2 patients and 6 mm in one) was released resulting in an immediate closure of the leak and recovery of the patient after completion of the pericardial drainage. The drainage was monitored 24h and patients were discharged on Day 2 with a good evolution over a median follow-up of 1.5 year. CT scan at 3 and 6 month showed total recovery. Conclusion In patients with left atrial wall perforation and tamponade related to failed transeptal puncture in patients under uninterrupted oral anticoagulation for AF ablation, rapid release of a closure device and pericardial evacuation allowed to successfully manage the cardiac tamponade and avoid a surgical option.