Clamping of the Aortic Arch Vessels During Normothermic Regional Perfusion Does Not Negatively Affect Donor Cardiac Function in Donation After Circulatory Death.

BACKGROUND: The hemodynamic effects of aortic arch vessel (AAV) clamping during normothermic regional perfusion (NRP) in donation after circulatory death is unknown. We investigated effects of AAV clamping during NRP compared with no clamping in a porcine model. METHODS: In 16 pigs, hemodynamic parameters were recorded including biventricular pressure-volume measurements and invasive blood pressure. Additionally, blood gas parameters and inflammatory cytokines were used to assess the effect of AAV clamping. The animals were centrally cannulated for NRP, and baseline measurements were obtained before hypoxic circulatory arrest was induced by halting mechanical ventilation. During an 8-min asystole period, the animals were randomized to clamp (n = 8) or no-clamp (n = 8) of the AAV before commencement of NRP. During NRP, circulation was supported with norepinephrine (NE) and dobutamine. After 30 min of NRP, animals were weaned and observed for 180 min post-NRP. RESULTS: All hearts were successfully reanimated and weaned from NRP. The nonclamp groups received significantly more NE to maintain a mean arterial pressure >60 mm Hg during and after NRP compared with the clamp group. There were no between group differences in blood pressure or cardiac output. Pressure-volume measurements demonstrated preserved cardiac function' including ejection fraction and diastolic and systolic function. No between group differences in inflammatory markers were observed. CONCLUSIONS: AAV clamping did not negatively affect donor cardiac function or inflammation after circulatory death and NRP. Significantly less NE was used to support in the clamp group than in the nonclamp group.

A Comparison of Pharyngeal Swabs and Tracheal Secretions for the Diagnosing of COVID-19.

The aim of this study was to compare the test results from patients who, within a short timescale, have been tested for COVID-19 using both a pharyngeal swab and tracheal secretion. Data were collected from the database of AUH, from patients hospitalized between 1 March 2020 and 1 March 2021 who, due to symptoms of COVID-19, were tested by a pharyngeal swab and by tracheal secretion. We found great agreement between oropharyngeal swab and tracheal secretion RT-PCR testing for the diagnosis of COVID-19, with 98.5% of double tests being concordant and only 1.5% being discordant. This finding may advocate a single-test strategy being either an oropharyngeal swab RT-PCR testing or tracheal secretion, although this study revealed 15.9% false negative oropharyngeal swabs.