Use of an interactive contouring module was an effective method to teach preclinical medical students about radiation oncology, with no significant difference in knowledge gained compared with a traditional didactic lecture; however, higher engagement among students completing the contouring module led to improved retention of knowledge of radiation side effects and greater interest in radiation oncology. These data suggest a potential benefit of integrating an interactive radiation oncology module into the preclinical medical school curriculum.
High-dose nitric oxide is a novel treatment associated with improved oxygenation and decreased tachypnea in pregnant patients with severe coronavirus disease 2019 (COVID-19).
IntroductionPostoperative acute kidney injury (AKI) is a common complication in cardiac surgery. Levels of intravascular haemolysis are strongly associated with postoperative AKI and with prolonged (>90 min) use of cardiopulmonary bypass (CPB). Ferrous plasma haemoglobin released into the circulation acts as a scavenger of nitric oxide (NO) produced by endothelial cells. Consequently, the vascular bioavailability of NO is reduced, leading to vasoconstriction and impaired renal function. In patients with cardiovascular risk factors, the endothelium is dysfunctional and cannot replenish the NO deficit. A previous clinical study in young cardiac surgical patients with rheumatic fever, without evidence of endothelial dysfunction, showed that supplementation of NO gas decreases AKI by converting ferrous plasma haemoglobin to ferric methaemoglobin, thus preserving vascular NO. In this current trial, we hypothesised that 24 hours administration of NO gas will reduce AKI following CPB in patients with endothelial dysfunction.MethodsThis is a single-centre, randomised (1:1) controlled, parallel-arm superiority trial that includes patients with endothelial dysfunction, stable kidney function and who are undergoing cardiac surgery procedures with an expected CPB duration >90 min. After randomisation, 80 parts per million (ppm) NO (intervention group) or 80 ppm nitrogen (N2, control group) are added to the gas mixture. Test gases (N2or NO) are delivered during CPB and for 24 hours after surgery. The primary study outcome is the occurrence of AKI among study groups. Key secondary outcomes include AKI severity, occurrence of renal replacement therapy, major adverse kidney events at 6 weeks after surgery and mortality. We are recruiting 250 patients, allowing detection of a 35% AKI relative risk reduction, assuming a two-sided error of 0.05.Ethics and disseminationThe Partners Human Research Committee approved this trial. Recruitment began in February 2017. Dissemination plans include presentations at scientific conferences, scientific publications and advertising flyers and posters at Massachusetts General Hospital.Trial registration numberNCT02836899.
Background
There is an increasing interest in safely delivering high dose of inhaled nitric oxide (NO) as an antimicrobial and antiviral therapeutics for spontaneously breathing patients. A novel NO delivery system is described.
Methods
We developed a gas delivery system that utilizes standard respiratory circuit connectors, a reservoir bag, and a scavenging chamber containing calcium hydroxide. The performance of the system was tested using a mechanical lung, assessing the NO concentration delivered at varying inspiratory flows. Safety was assessed in vitro and in vivo by measuring nitrogen dioxide (NO
2
) levels in the delivered NO gas. Lastly, we measured the inspired and expired NO and NO
2
of this system in 5 healthy subjects during a 15-min administration of high dose NO (160 parts-per-million, ppm) using our delivery system.
Results
The system demonstrated stable delivery of prescribed NO levels at various inspiratory flow rates (0–50 L/min). The reservoir bag and a high flow of entering air minimized the oscillation of NO concentrations during inspiration on average 4.6 ppm for each 10 L/min increment in lung inspiratory flow.
The calcium hydroxide scavenger reduced the inhaled NO
2
concentration on average 0.9 ppm (95% CI -1.58, −0.22;
p
= .01). We performed 49 NO administrations of 160 ppm in 5 subjects. The average concentration of inspired NO was 164.8
10.74 ppm, with inspired NO
2
levels of 0.7
0.13 ppm. The subjects did not experience any adverse events; transcutaneous methemoglobin concentrations increased from 1.05
0.58 to 2.26
0.47%.
Conclusions
The system we developed to administer high-dose NO for inhalation is easy to build, reliable, was well tolerated in healthy subjects.
The majority of articles using the MDRD equation to estimate GFR did so using values where the estimate is quite unstable (eGFR >60 mL/min per 1.73 m(2)), thereby limiting the validity of the claims. Urologists should reconsider the use of MDRD for comparing estimates of GFR in patients with normal renal function in published articles.
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