Mortality in COVID-19 is not merely a question of resource availability

After the initial outbreak of COVID-19 in Wuhan, China, in December, 2019, the first 16 cases of COVID-19 in Germany were identified between Jan 27, and Feb 11, 2020.¹ Although these 16 cases were contained successfully, further introductions of COVID-19 into Germany by tourists returning from Austria and super-spreading events, such as the carnival festivities in mid-February, led to a nationwide spread of the virus within a few weeks. Seeing the developments in Italy and Spain, with an exponential surge of intensive care unit (ICU) admissions, a rapidly increasing death toll, and partial overwhelming of local health-care systems, German authorities introduced physical distancing and other lockdown measures in the second half of March, 2020, at a time when fewer than 1000 of more than 30 000 ICU beds were occupied with patients with COVID-19. As a result of these measures, the German health-care system, which has one of the highest numbers of ICU beds per capita worldwide,² has not been overwhelmed by the COVID-19 pandemic, with at least 40% of all registered ICU beds available even at the height of the epidemic in April, 2020.

This situation offers the opportunity to study the outcomes of a large group of patients with COVID-19 in a health-care system with sufficient resources for treating every patient with all therapeutic options of modern intensive care medicine. To this end, Christian Karagiannidis and colleagues³ evaluated a cohort comprising 10 021 patients diagnosed with COVID-19 who were admitted to 920 hospitals across Germany between Feb 26, 2020, and April 19, 2020. Data were retrieved from a large group of German statutory health insurance funds, accounting for approximately one-third of the total population.

Despite the availability of intensive care resources for all patients, Karagiannidis and colleagues found a high mortality of 22% in hospitalised patients (2229 of 10 021). The median age of patients in the studied cohort of 72 years (IQR 57–82) was higher than in other published COVID-19 cohorts. For example, a median age of 63 years (52–75) was reported in the New York cohort,⁴ which comprised 2634 patients with definite outcomes of discharge or death, and a median age of only 47 years (35–58) was reported in an early Chinese cohort.⁵ Albeit in an older population, the mortality reported by Karagiannidis and colleagues was similar to that reported in New York (21%),⁴ but was higher than that in the younger patients in China (1·4%).⁵ Karagiannidis and colleagues found a high mortality of 72% (280 of 388) in patients aged 80 years and older who required mechanical ventilation. An even higher mortality of 97% was reported for patients older than 65 years and requiring mechanical ventilation in the New York cohort.⁴ The proportion of patients requiring mechanical ventilation was similar in the German and New York cohorts (17% and 20%, respectively). Of note, the median length of hospital stay differed between these two cohorts (10 days [5–19] in the German cohort and 4 days [2–7] in the New York cohort), which might reflect the different strains on the two health-care systems.

Karagiannidis and colleagues' findings support the strong association of poor outcomes with demographic characteristics (older age and male sex) and comorbidities described in previous studies,4, 5 with a mortality rate of up to 73% in patients requiring both mechanical ventilation and dialysis.

Although the high mortality observed in this study could be considered disheartening, the data presented by Karagiannidis and colleagues were obtained during the first wave of COVID-19, when reliable data on the therapeutic effectiveness of potential treatments were scarce. Interventions such as early administration of remdesivir to patients not yet requiring mechanical ventilation⁶ and administration of dexamethasone later in the course of the disease to patients requiring supplemental oxygen or on mechanical ventilation⁷ could improve outcomes for future patients. A histopathological study has shown a high prevalence of alveolar capillary microthrombi in patients with COVID-19,⁸ which is consistent with an elevation of ventilated but not perfused lung units observed in mechanically ventilated patients with COVID-19-associated acute respiratory distress syndrome.⁹ Conceivably, anticoagulant treatment could become an important therapeutic measure for treating patients with severe disease in the future.¹⁰ The optimal timing of intubation is still being debated, as is the optimal strategy for adjusting positive end-expiratory pressure in patients on invasive mechanical ventilation.

Despite these potential therapeutic advances, COVID-19 remains a life-threatening disease, even if sufficient resources for maximum intensive care therapy are available for all patients affected by the disease.

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