Spotlight: The situation in a German COVID-19 hospital

Severe COVID-19 | 443

In a multivariate Cox model, older age, chronic cardiac disease (adjusted HR 1.76) and chronic pulmonary disease (2.94) were independently associated with in-hospital mortality. This was also seen for higher concentrations of interleukin-6 and D-dimer, highlighting the role of systemic inflammation and endothelial-vascular damage in the development of organ dysfunction. COVID-19 characteristics may vary considerably by location. In a United States cohort of 2215 adults who were admitted to ICUs at 65 sites, 784 (35.4%) died within 28 days (Gupta 2020). However, mortality showed an extremely wide variation among hospitals, ranging from 6.6% to 80.8%. Factors associated with death included older age, male sex, obesity, coronary artery disease, cancer, acute organ dysfunction, and, importantly, admission to a hospital with fewer intensive care unit beds. Of note, patients admitted to hospitals with fewer than 50 ICU beds versus at least 100 ICU beds had a higher risk of death (OR 3.28; 95% CI, 2.16-4.99). Another large prospective observational study in the United Kingdom presented clinical data from 20,133 patients, admitted to (or diagnosed in) 208 acute care hospitals in the UK until April 19 (Docherty 2020). Median age was 73 years (interquartile range 58-82) and 60% were men. Co-morbidities were common, namely chronic cardiac disease (31%), diabetes (21%) and nonasthmatic chronic pulmonary disease (18%). Overall, 41% of patients were discharged alive, 26% died, and 34% continued to receive care. 17% required admission to high dependency or intensive care units; of these, 28% were discharged alive, 32% died, and 41% continued to receive care. Of those receiving mechanical ventilation, 17% were discharged alive, 37% died, and 46% remained in hospital. Increasing age, male sex, and co-morbidities including chronic cardiac disease, non-asthmatic chronic pulmonary disease, chronic kidney disease, liver disease and obesity were associated with higher mortality in hospital.

The Klinik Mühldorf am Inn Hospital was designated as a COVID-19 clinic on March 16, 2020, in order to keep other facilities free for emergencies and elective care. From that day, a total of 276 SARS-CoV-2 positive and 730 suspected cases were treated there. The largest number of symptomatic patients was admitted at the end of March, and the highest number of simultaneously treated SARS-CoV-2 positive patients was 100 patients on April 6, 2020. In total, 18.5% of these in-patients received intensive care during their hospital stay. The peak of intensive care patients was highest on April 10, 2020 with 17 patients. Due to timely preparation, no triage decisions about withholding ventilation treatments had to be made. All COVID-19 patients who had to be

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treated in the hospital until July 15th, 2020, and who were in need of mechanical ventilation received it. A total of 51 COVID-19 patients required intensive care treatment (18.5% of all COVID-19 in-patients) and 37 patients (13.4%) were ventilated during their intensive care stay. Seven patients were directly intubated and invasively ventilated without a non-invasive ventilation (NIV) attempt after administration of oxygen through a nasal cannula or mask alone. In total, 9/37 patients did not wish to be intubated. In 16 patients, a prone positioning was carried out, including one patient under NIV. Management and mechanical ventilation

The cardinal COVID-19 symptom leading to intensive care admission is hypoxemic respiratory failure with tachypnea (> 30/min). Initially, in order to protect staff from aerosols as much as possible, intubation and invasive mechanical ventilation was preferred over non-invasive ventilation (NIV) and nasal high-flow (HFNC). Likewise, due to lack of knowledge and experience, recommendations on how to deal with these patients were not homogeneous, and ARDS ventilation was the preferred technique (Griffiths 2019). According to the ARDS recommendations, patients should be ventilated with a tidal volume (VT) of < 6ml/kg standardized body weight, a peak pressure of < 30 cmH2O and a PEEP based on the ARDS network table. In one study, these ventilator settings were used except for the lower PEEP/higher FiO2 table. The driving pressure should not exceed 15 mbar. In addition, prone positioning was recommended in case of a PaO2/FiO2 < 150 for more than 16 hours (Ziehr 2020). Quickly it became obvious that acute respiratory distress syndrome (ARDS) in COVID-19 is not the same as ARDS. COVID-19 in patients with ARDS – CARDs –appears to include an important vascular insult that potentially mandates a different treatment approach than customarily used for ARDS. It may be helpful to categorize patients as having either type L or H phenotype and accept that different ventilatory approaches are needed, depending on the underlying physiology (Marini 2020). In type L (low lung elastance, high compliance, low response to PEEP), infiltrates are often limited in extent and initially characterized by a ground-glass pattern on CT that signifies interstitial rather than alveolar edema. Many patients do not appear overtly dyspneic and may stabilize at this stage without deterioration. Others may transit to a clinical picture more characteristic of typical ARDS: Type H shows extensive CT consolidations, high elastance (low compliance) and high PEEP response. Clearly, types L and H are the conceptual extremes of a spectrum that includes intermediate stages.