Background Atrial fibrillation (AF) is common in intensive care unit (ICU) patients and is associated with poor outcomes. Different management strategies exist, but the evidence is limited and derived from non‐ICU patients. This international survey of ICU doctors evaluated the preferred management of acute AF in ICU patients. Method We conducted an international online survey of ICU doctors with 27 questions about the preferred management of acute AF in the ICU, including antiarrhythmic therapy in hemodynamically stable and unstable patients and use of anticoagulant therapy. Results A total of 910 respondents from 70 ICUs in 14 countries participated in the survey with 24%–100% of doctors from sites responding. Most ICUs (80%) did not have a local guideline for the management of acute AF. The preferred first‐line strategy for the management of hemodynamically stable patients with acute AF was observation (95% of respondents), rhythm control (3%), or rate control (2%). For hemodynamically unstable patients, the preferred strategy was observation (48%), rhythm control (48%), or rate control (4%). Overall, preferred antiarrhythmic interventions included amiodarone, direct current cardioversion, beta‐blockers other than sotalol, and magnesium in that order. A total of 67% preferred using anticoagulant therapy in ICU patients with AF, among whom 61% preferred therapeutic dose anticoagulants and 39% prophylactic dose anticoagulants. Conclusion This international survey indicated considerable practice variation among ICU doctors in the clinical management of acute AF, including the overall management strategies and the use of antiarrhythmic interventions and anticoagulants.

BACKGROUND: Transcutaneous measurements of CO 2 and O 2 (P tcCO 2 , P tcO 2 ) are noninvasive and allow for continuous monitoring in adults with exacerbation of COPD, but substantial accuracy issues may exist. We investigated agreement between results of arterial blood gas analysis and transcutaneous measurements of CO 2 and O 2 in patients with COPD. METHODS: Adult subjects were monitored after acute admission to a respiratory intermediate care unit or ICU due to exacerbation of COPD and with ongoing noninvasive ventilation or immediately following extubation. Monitored variables were continuous transcutaneous measurement and simultaneous routine arterial blood gas analysis. Agreement between measurements was assessed by calculating bias with 95% limits of agreement for single-point estimates of P tcCO 2 versus P aCO 2 and versus P aO 2 , and for changes in transcutaneous measurements between 2 time points (DP tcCO 2 and DP tcO 2 ). We considered limits of agreement within 6 7.5 mm Hg to be acceptable. RESULTS: A total of 57 transcutaneous measurements were made in 20 subjects for comparison with concurrent arterial blood gas analysis at 36 time points. The bias (limits of agreement) for P tcCO 2 and P tcO 2 was 2.5 mm Hg (-10.6 to 15.6 mm Hg) and 11.2 mm Hg (-28.2 to 50.6 mm Hg), respectively. The bias for DP tcCO 2 and DP tcO 2 was 2.3 mm Hg (-3.8 to 8.3 mm Hg) and -5.3 mm Hg (-37.5 to 27 mm Hg), respectively. CONCLUSIONS: P tcCO 2 and P tcO 2 did not accurately reflect results from arterial blood gas analyses in this study of mostly hypercapnic subjects. Agreement between changes in CO 2 during the monitoring period was acceptable, however, and transcutaneous monitoring may be used for continuous monitoring of P CO 2 in conjunction with arterial blood gas analysis for reference.

Background: Melatonin is widely employed as a hypnotic in various patient groups.In intensive care patients, melatonin seems to be increasingly used due to potential clinical effects and a favourable safety profile.Objectives: We aimed to investigate the extend of usage and clinical practice of melatonin therapy in intensive care departments in Denmark.Design: Data from regional hospital pharmacies and the Danish Intensive Care Database were used to estimate defined daily dose and defined daily dose per 1000 ICU admission days. Also, related expenses in the period 2015-2019. Finally, a questionnaire describing the clinical practice of melatonin therapy was provided to all Danish intensive care departments. Principal Observations: The usage of melatonin in intensive care departments in Denmark increased from 21,300 DDD (200.0 DDD per 1000 ICU admission days) in 2015 to 52,170 DDD (560.7 DDD per 1000 ICU admission days) in 2019. A total of 32 ICU departments participated in the study (97% of all Danish ICU departments). All included ICU departments employed melatonin as a hypnotic. Nineteen percent of included departments administered melatonin to all admitted patients, whereas 25% of departments rarely administered melatonin. Magistral melatonin 3-mg tablets was the most employed drug dose/formulation. Increased doses of melatonin were administered in selected patients. Melatonin was considered safe by prescribing clinicians. Conclusions: Melatonin is widely and increasingly used in Danish intensive care departments. The more than doubled usage of melatonin in the study period advocates for further studies employing validated outcomes of sleep and other patientrelevant outcomes.Editorial Comment: This study documents that melatonin is frequently used as a hypnotic in Danish intensive care units during recent years despite a shortage of reliable evidence to support a recommendation to treat with melatonin in this context. These results support a need for conducting clinical trials to determine whether or not there is a beneficial effect of melatonin treatment in critically ill patients.