Summary Using biased‐coin sequential allocation, we sought to determine the effective time interval in 90% of healthy parturients to achieve a target endpoint end‐tidal oxygen of ≥ 90% using standard flow rate facemask and high‐flow nasal oxygen. Eighty healthy parturients were randomly assigned to standard facemask (n = 40) or high‐flow nasal oxygen (n = 40) groups; half of the parturients in the high‐flow nasal oxygen group also used a simple no‐flow facemask to minimise air entrainment. The effective time interval for 90% of parturients to achieve the target endpoint for standard facemask was 3.6 min (95%CI 3.3–6.7 min), but could not be estimated for the high‐flow nasal oxygen groups with or without an additional simple facemask, as eight minutes was insufficient to achieve the target endpoint for 55% and 92% of parturients, respectively. Furthermore, after three minutes, the target endpoint was reached by 71% in the standard facemask group vs. 0% in the high‐flow nasal oxygen groups. After four minutes, the target endpoint was reached by 100% in the standard facemask, 80% in the high‐flow nasal oxygen with simple facemask and 67% in the high‐flow nasal oxygen groups. Beyond four minutes, there was no improvement in pre‐oxygenation success using high‐flow nasal oxygen. In conclusion, under the conditions of our study, the effective time interval for 90% of parturients to achieve an end‐tidal oxygen ≥ 90% for standard flow rate facemask was estimated to be 3.6 min, but could not be estimated for high‐flow nasal oxygen groups even after eight minutes.

Objectives To determine the efficacy and safety of sildenafil citrate to improve outcomes in pregnancies complicated by early-onset, dismal prognosis, fetal growth restriction (FGR). Eligibility: women ≥ 18 years, singleton, 18 + 0–27 + 6 weeks’ gestation, estimated fetal weight < 700 g, low PLFG, and ≥ 1 of (i) abdominal circumference < 10th percentile for gestational age (GA); or (ii) reduced growth velocity and either abnormal uterine artery Doppler or prior early-onset FGR with adverse outcome. Ineligibility criteria included: planned termination or reversed umbilical artery end-diastolic flow. Eligibility confirmed by placental growth factor (PlGF) < 5 th percentile for GA measured post randomization. Women randomly received (1:1) either sildenafil 25 mg three times daily or matched placebo until either delivery or 31 + 6 weeks. Primary outcome: delivery GA. The trial stopped early when Dutch STRIDER signalled potential harm; despite distinct eligibility criteria and IRB and DSMB support to continue, because of futility. NCT02442492 [registered 13/05/2015]. Results Between May 2017 and June 2018, 21 (90 planned) women were randomised [10 sildenafil; 11 placebo (1 withdrawal)]. Baseline characteristics, PlGF levels, maternal and perinatal outcomes, and adverse events did not differ. Delivery GA: 26 + 6 weeks (sildenafil) vs 29 + 2 weeks (placebo); p = 0.200. Data will contribute to an individual participant data meta-analysis.

The eight 304 TL pass tubes in the Varian V-2100B magnet power supply have been replaced with high voltage power transistors. The inadequate protection against high voltage surges in a previous circuit has been corrected, using a fast acting SCR clamp. In addition, further circuit modifications have reduced ripple and thus extended the useful regulating range of the power supply.

No abstract