ABSTRACT
BACKGROUND: In the absence of lung biopsy, there are various algorithms for the diagnosis of invasive pulmonary aspergillosis (IPA) in critically ill patients that rely on clinical signs, underlying conditions, radiological features and mycology. The aim of the present study was to compare four diagnostic algorithms in their ability to differentiate between probable IPA (i.e., requiring treatment) and colonisation. METHODS: For this diagnostic accuracy study, we included a mixed ICU population with a positive Aspergillus culture from respiratory secretions and applied four different diagnostic algorithms to them. We compared agreement among the four algorithms. In a subgroup of patients with lung tissue histopathology available, we determined the sensitivity and specificity of the single algorithms. RESULTS: A total number of 684 critically ill patients (69% medical/31% surgical) were included between 2005 and 2020. Overall, 79% (n = 543) of patients fulfilled the criteria for probable IPA according to at least one diagnostic algorithm. Only 4% of patients (n = 29) fulfilled the criteria for probable IPA according to all four algorithms. Agreement among the four diagnostic criteria was low (Cohen's kappa 0.07-0.29). From 85 patients with histopathological examination of lung tissue, 40% (n = 34) had confirmed IPA. The new EORTC/MSGERC ICU working group criteria had high specificity (0.59 [0.41-0.75]) and sensitivity (0.73 [0.59-0.85]). CONCLUSIONS: In a cohort of mixed ICU patients, the agreement among four algorithms for the diagnosis of IPA was low. Although improved by the latest diagnostic criteria, the discrimination of invasive fungal infection from Aspergillus colonisation in critically ill patients remains challenging and requires further optimization.
Subject(s)
Invasive Pulmonary Aspergillosis , Aspergillus , Cohort Studies , Critical Illness , Humans , Invasive Pulmonary Aspergillosis/diagnosis , Invasive Pulmonary Aspergillosis/microbiology , Sensitivity and SpecificityABSTRACT
High-flow oxygen therapy (high flow nasal cannula, HFNC), in which an oxygen-air gas mixture is applied at flow rates between 30 and 70â¯L/min, is a technically simple and highly effective procedure for the treatment of hypoxemic respiratory insufficiency. Furthermore, HFNC can be used during bronchoscopy for oxygenation, before intubation for preoxygenation, and after extubation to avoid reintubation. The high gas flow prevents the patient from inspiring ambient air, allowing precise adjustment of an inspiratory oxygen fraction; furthermore, a positive end-expiratory pressure is built up by a resulting dynamic pressure, mucociliary clearance is improved by humidification and warming of the air breathed and the work of breathing is reduced by flushing the upper airways. Compared with conventional oxygen therapy, aerosol formation is not increased by HFNC; therefore, this procedure can also be used for patients with coronavirus disease 2019 (COVID-19). In hypercapnic respiratory failure the data are inconclusive and in this case noninvasive ventilation should currently be preferred instead of HFNC. It is important to remember that patients treated with HFNC are critically ill and therefore require continuous monitoring. It must be ensured that an escalation of therapy, e.g. to intubation and invasive ventilation, can be performed at any time.
ABSTRACT
Mit der High-Flow-Sauerstofftherapie („high flow nasal cannula“ [HFNC]), bei der ein Sauerstoff-Luft-Gasgemisch mit Flüssen zwischen 30 und 70 l/min appliziert wird, steht ein technisch einfaches und hocheffektives Verfahren zur Therapie einer respiratorischen Insuffizienz zur Verfügung. Des Weiteren kann die HFNC während einer Bronchoskopie zur Oxygenierung, vor einer Intubation zur Präoxygenierung und nach Extubation zur Vermeidung einer Re-Intubation verwendet werden. Durch die hohen Gasflüsse wird vermieden, dass der Patient Umgebungsluft inspiriert, sodass eine präzise Einstellung einer inspiratorischen Sauerstofffraktion möglich ist, des Weiteren wird durch einen entstehenden Staudruck ein positiver endexspiratorischer Druck aufgebaut, durch die Anfeuchtung und Erwärmung der Atemluft die mukoziliäre Clearance verbessert sowie die Atemarbeit durch Auswaschen der oberen Atemwege verringert. Im Vergleich zur konventionellen Sauerstofftherapie ist die Aerosolbildung durch eine HFNC nicht erhöht, sodass dieses Verfahren auch bei COVID-19 eingesetzt werden kann. Beim hyperkapnischen Lungenversagen liegen bisher keine konklusiven Daten für die Effekte der HFNC vor, hier sollte bevorzugt eine nichtinvasive Beatmung statt einer HFNC erfolgen. Bei der Anwendung darf nicht vergessen werden, dass die mit HFNC behandelten Patienten kritisch krank sind und daher kontinuierlich überwacht werden müssen. So muss sichergestellt sein, dass jederzeit eine Eskalation z. B. auf eine Intubation und invasive Beatmung erfolgen kann.