Editorial for Special Issue "Antimicrobial Therapy in Intensive Care Unit".

Life-threatening infections, either as the initial reason for an admission to the intensive care unit (ICU) or acquired in the ICU, are especially common among critically ill patients [...].

Mortality of intubated patients with COVID-19 during first and subsequent waves: a meta-analysis involving 363,660 patients from 43 countries.

BACKGROUND: We attempted to investigate the change in mortality of intubated patients with coronavirus disease (COVID-19) from first to subsequent waves across several countries. METHODS: We pre-registered our meta-analysis with PROSPERO [Anonymized]. We searched PubMed, Scopus, and gray literature for observational studies reporting data on all-cause mortality of intubated patients with COVID-19 recruited both during first and subsequent waves of the pandemic. We considered studies published after 31 August 2020 up to 12 July 2021. The primary outcome of the meta-analysis was all-cause mortality. We used a random effects model to calculate pooled risk ratio (RR) and 95% confidence intervals (CI). RESULTS: By incorporating data of 363,660 patients from 43 countries included in 28 studies, we found that all-cause mortality of intubated patients with COVID-19 increased from first to subsequent waves (from 62.2% to 72.6%; RR 0.90, 95% CI 0.85-0.94, p < 0.00001). This finding was independent of the geo-economic variation of the included studies and persisted in several pre-specified subgroup and sensitivity analyses. CONCLUSIONS: The robust finding of this meta-analysis suggests that mortality of intubated patients with COVID-19 did not improve over time. Future research should target this group of patients to further optimize their management.

Serum inflammatory and brain injury biomarkers in COVID-19 patients admitted to intensive care unit: A pilot study.

Background: The aim of this study was to measure serum brain injury biomarkers in patients with COVID-19 admitted to intensive care unit (ICU), without evidence of brain impairment, and to determine potential correlations with systemic inflammatory markers, illness severity, and outcome. Methods: In patients admitted to the ICU with COVID-19, without clinical evidence of brain injury, blood S100 calcium-binding protein B (S100B), neuron-specific enolase (NSE) and interleukin-6 (IL-6) were measured on admission. Clinical, routine laboratory data and illness severity were recorded. Comparisons between 28-day survivors and non-survivors and correlations of neurological biomarkers to other laboratory data and illness severity, were analyzed. Results: We included 50 patients, median age 64 [IQR 58-78] years, 39 (78%) males, 39 (78%) mechanically ventilated and 11 (22%) under high flow nasal oxygen treatment. S100B and NSE were increased in 19 (38%) and 45 (90%) patients, respectively. S100B was significantly elevated in non-survivors compared to survivors: 0.15 [0.10-0.29] versus 0.11 [0.07-0.17] µg/L, respectively, (p = 0.03), and significantly correlated with age, IL-6, arterial lactate, noradrenaline dose, illness severity and lymphocyte count. IL-6 was significantly correlated with C-reactive protein, noradrenaline dose and organ failure severity. NSE was correlated only with lactate dehydrogenase. Conclusion: Brain injury biomarkers were frequently elevated in COVID-19 ICU patients, in the absence of clinical evidence of brain injury. S100B was significantly correlated with IL-6, low lymphocyte count, hypoperfusion indices, illness severity, and short-term outcome. These findings indicate a possible brain astrocytes and neurons involvement, also suggesting a broader role of S100B in systemic inflammatory response.

Epidemiology of Candidemia and Fluconazole Resistance in an ICU before and during the COVID-19 Pandemic Era.

The objectives of this study were to investigate the incidence of candidemia, as well as the factors associated with Candida species distribution and fluconazole resistance, among patients admitted to the intensive care unit (ICU) during the COVID-19 pandemic, as compared to two pre-pandemic periods. All patients admitted to the ICU due to COVID-19 from March 2020 to October 2021, as well as during two pre-pandemic periods (2005-2008 and 2012-2015), who developed candidemia, were included. During the COVID-19 study period, the incidence of candidemia was 10.2%, significantly higher compared with 3.2% and 4.2% in the two pre-pandemic periods, respectively. The proportion of non-albicans Candida species increased (from 60.6% to 62.3% and 75.8%, respectively), with a predominance of C. parapsilosis. A marked increase in fluconazole resistance (from 31% to 37.7% and 48.4%, respectively) was also observed. Regarding the total patient population with candidemia (n = 205), fluconazole resistance was independently associated with ICU length of stay (LOS) before candidemia (OR 1.03; CI: 1.01-1.06, p = 0.003), whereas the presence of shock at candidemia onset was associated with C. albicans (OR 6.89; CI: 2.2-25, p = 0.001), and with fluconazole-susceptible species (OR 0.23; CI: 0.07-0.64, p = 0.006). In conclusion, substantial increases in the incidence of candidemia, in non-albicansCandida species, and in fluconazole resistance were found in patients admitted to the ICU due to COVID-19, compared to pre-pandemic periods. At candidemia onset, prolonged ICU LOS was associated with fluconazole-resistant and the presence of shock with fluconazole-susceptible species.

Rapidly improving acute respiratory distress syndrome in COVID-19: a multi-centre observational study.

BACKGROUND: Before the pandemic of coronavirus disease (COVID-19), rapidly improving acute respiratory distress syndrome (ARDS), mostly defined by early extubation, had been recognized as an increasingly prevalent subphenotype (making up 15-24% of all ARDS cases), associated with good prognosis (10% mortality in ARDSNet trials). We attempted to determine the prevalence and prognosis of rapidly improving ARDS and of persistent severe ARDS related to COVID-19. METHODS: We included consecutive patients with COVID-19 receiving invasive mechanical ventilation in three intensive care units (ICU) during the second pandemic wave in Greece. We defined rapidly improving ARDS as extubation or a partial pressure of arterial oxygen to fraction of inspired oxygen ratio (PaO2:FiO2) greater than 300 on the first day following intubation. We defined persistent severe ARDS as PaO2:FiO2 of equal to or less than 100 on the second day following intubation. RESULTS: A total of 280 intubated patients met criteria of ARDS with a median PaO2:FiO2 of 125.0 (interquartile range 93.0-161.0) on day of intubation, and overall ICU-mortality of 52.5% (ranging from 24.3 to 66.9% across the three participating sites). Prevalence of rapidly improving ARDS was 3.9% (11 of 280 patients); no extubation occurred on the first day following intubation. ICU-mortality of patients with rapidly improving ARDS was 54.5%. This low prevalence and high mortality rate of rapidly improving ARDS were consistent across participating sites. Prevalence of persistent severe ARDS was 12.1% and corresponding mortality was 82.4%. CONCLUSIONS: Rapidly improving ARDS was not prevalent and was not associated with good prognosis among patients with COVID-19. This is starkly different from what has been previously reported for patients with ARDS not related to COVID-19. Our results on both rapidly improving ARDS and persistent severe ARDS may contribute to our understanding of trajectory of ARDS and its association with prognosis in patients with COVID-19.

Older adults with severe coronavirus disease 2019 admitted to intensive care unit: prevalence, characteristics and risk factors for mortality.

BACKGROUND: Although older adults are at high risk for severe coronavirus disease 2019 (COVID-19) requiring intensive care unit (ICU) admission, age is often used as a selection criterion in case of ICU beds scarcity. We sought to compare the proportion, clinical features and mortality between patients ≥70 years old and younger ICU patients with COVID-19. METHODS: All patients, consecutively admitted to our COVID ICU, where age was not used as an admission criterion, from March 2020 through April 2021, were included. Demographics, clinical and laboratory characteristics were recorded. Illness severity and Charlson comorbidity Index (CCI) were calculated. Patients≥70 years old were compared to youngers. RESULTS: Of 458 patients (68 [59-76] years, 70% males), 206 (45%) were ≥70 years old. Compared to younger, older patients had higher illness severity scores (APACHE II 18 [14-23] versus 12 [9-16], P<0.001, SOFA 8 [6-10] versus 6 [2-8], P<0.001, CCI 5 [4-6] versus 2 [1-3], P<0.001), increased need for mechanical ventilation (92% vs. 72%, P<0.001) and ICU mortality (74% versus. 29%, P<0.001). Age (HR: 1.045, CI: 1.02-1.07, P=0.001), CCI (HR: 1.135, CI: 1.037-1.243, P=0.006) and APACHE II (HR: 1.070, CI: 1.013-1.130, P=0.015) were independently associated with mortality. Among comorbidities, obesity, chronic pulmonary disease and chronic kidney disease were independent risk factors for death. CONCLUSIONS: When age is not used as criterion for admission to COVID ICU, patients ≥70 years old represent a considerable proportion and, compared to younger ones, they have higher mortality. Age, severity of illness and CCI, and certain comorbidities are independent risk factors for mortality.

Effect of Vitamin C on Clinical Outcomes of Critically Ill Patients With COVID-19: An Observational Study and Subsequent Meta-Analysis.

BACKGROUND: Whether vitamin C provides any benefit when administered in critically ill patients, including those with coronavirus disease (COVID-19), is controversial. We endeavored to estimate the effect of administration of vitamin C on clinical outcomes of critically ill patients with COVID-19 by performing an observational study and subsequent meta-analysis. METHODS: Firstly, we conducted an observational study of critically ill patients with laboratory-confirmed COVID-19 who consecutively underwent invasive mechanical ventilation in an academic intensive care unit (ICU) during the second pandemic wave. We compared all-cause mortality of patients receiving vitamin C ("vitamin C" group) or not ("control" group) on top of standard-of-care. Subsequently, we systematically searched PubMed and CENTRAL for relevant studies, which reported on all-cause mortality (primary outcome) and/or morbidity of critically ill patients with COVID-19 receiving vitamin C or not treatment. Pooled risk ratio (RR) and 95% confidence intervals (CI) were calculated using a random effects model. The meta-analysis was registered with PROSPERO. RESULTS: In the observational study, baseline characteristics were comparable between the two groups. Mortality was 20.0% (2/10) in the vitamin C group vs. 47.6% (49/103; p = 0.11) in the control group. Subsequently, the meta-analysis included 11 studies (6 observational; five randomized controlled trials) enrolling 1,807 critically ill patients with COVID-19. Mortality of patients receiving vitamin C on top of standard-of-care was not lower than patients receiving standard-of-care alone (25.8 vs. 34.7%; RR 0.85, 95% CI 0.57-1.26; p = 0.42). CONCLUSIONS: After combining results of our observational cohort with those of relevant studies into a meta-analysis of data from 1,807 patients, we found that administration vitamin C as opposed to standard-of-care alone might not be associated with lower of mortality among critically ill patients with COVID-19. Additional evidence is anticipated from relevant large randomized controlled trials which are currently underway. SYSTEMATIC REVIEW REGISTRATION: https://www.crd.york.ac.uk/prospero/, identifier: CRD42021276655.

Lactate and Lactate-to-Pyruvate Ratio in Critically Ill COVID-19 Patients: A Pilot Study.

A limited number of coronavirus disease-19 (COVID-19) cases may require treatment in an intensive care unit (ICU). Arterial blood lactate levels are routinely measured in the ICU to estimate disease severity, predict poor outcomes, and monitor therapeutic handlings. A number of studies have suggested that, simultaneously with lactate, pyruvate should also be measured, providing augmented prognostic ability, and a better understanding of the underlying metabolic alterations in ICU patients. Hence, the aim of the present study was to elucidate the relationship between lactate levels and the lactate-to-pyruvate (LP) ratio with the clinical outcome in mechanically ventilated COVID-19 patients. Lactate and pyruvate were serially measured during the first 24 h of ICU stay. A group of ICU non-COVID-19 patients was used as a comparison group. The majority of COVID-19 patients (82.5%) had normal lactate levels and a normal LP ratio on ICU admission (normal metabolic pattern). A small, yet significant, percentage of patients had either elevated lactate levels or a high LP ratio (abnormal metabolic pattern); these patients exhibited a significantly higher risk of ICU mortality compared to the patients with a normal metabolic pattern (72.7% vs. 34.6%, p = 0.04). In our critically ill COVID-19 patients, elevated lactate levels or high LP ratios on admission to the ICU could be associated with poor clinical outcome.

Fewer Intubations but Higher Mortality Among Intubated Coronavirus Disease 2019 Patients During the Second Than the First Wave.

Since changes in pharmacological treatments for severely ill patients with coronavirus disease 2019 have been incorporated into clinical practice, both by their use (corticosteroids and remdesivir) and by stopping them (e.g., hydroxychloroquine), we sought to compare the rate of intubation and mortality of intubated patients in our ICUs between the first and second waves of the pandemic. DESIGN: Single-center, observational. SETTING: Four coronavirus disease 2019 designated ICUs at an urban Greek teaching hospital. PATIENTS: All adult patients with coronavirus disease 2019 consecutively admitted to ICU during the first (n = 50) and second (n = 212) waves of the pandemic. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The percentage of intubated ICU patients dropped from 82% during the first wave to 66% during the second wave (p = 0.042). However, the absolute number of intubated ICU patients was lower during the first than the second wave (41 vs 140 patients). ICU or hospital mortality of intubated patients increased from 39% during the first wave to 60% during the second wave (p = 0.028). The binary logistic regression for hospital mortality as the dependent variable in intubated patients and covariates the age, Acute Physiology and Chronic Health Evaluation II score, cardiovascular comorbidity, lactate, positive end-expiratory pressure, Sequential Organ Failure Assessment score, and wave, distinguished only Acute Physiology and Chronic Health Evaluation II (odds ratio, 1.40 with 95% CI, 1.14-1.72; p = 0.001) as the sole independent predictor of hospital mortality. CONCLUSIONS: Pharmacological adaptations and other measures may have led to fewer intubations over time. However, these changes do not seem to be translated into improved outcomes of intubated patients. Perhaps the same change in the use of drugs and protocols that could cause fewer intubations of ICU patients might be a reason of increased mortality in those patients who are eventually intubated. Furthermore, the relative staff inexperience and overall increase in patients' comorbidities during the second wave could have contributed to increased Acute Physiology and Chronic Health Evaluation II score and mortality of intubated patients.

Elderly adults with COVID-19 admitted to intensive care unit: A narrative review.

BACKGROUND: In the context of the Coronavirus disease 2019 (COVID-19) pandemic, it has been reported that elderly patients are particularly at risk of developing severe illness and exhibiting increased mortality. While many studies on hospitalized elderly patients with COVID-19 have been published, limited information is available on the characteristics and clinical outcomes of those elderly patients admitted to intensive care unit (ICU). AIM: To review the available evidence of the clinical data of elderly patients admitted to the ICU due to COVID-19. METHODS: We searched for published articles available in English literature to identify those studies conducted in critically ill patients admitted to the ICU due to COVID-19, either exclusively designed for the elderly or for the whole ICU population with COVID-19, provided that analyses according to the patients' age had been conducted. RESULTS: Only one study exclusively focusing on critically ill elderly patients admitted to the ICU due to COVID-19 was found. Eighteen additional studies involving 17011 ICU patients and providing information for elderly patients as a subset of the whole study population have also been included in the present review article. Among the whole patient population, included in these studies, 8310 patients were older than 65 years of age and 2630 patients were older than 70 years. Clinical manifestations were similar for all patients; however, compared to younger ones, they suffered from more comorbidities and showed a varied, albeit high mortality. CONCLUSION: In summary, at present, although elderly patients constitute a considerable proportion of critically ill patients admitted to the ICU due to severe COVID-19, studies providing specific information are limited. The evidence so far suggests that advanced age and comorbidities are associated with worse clinical outcome. Future studies exclusively designed for this vulnerable group are needed.

Effect of timing of intubation on clinical outcomes of critically ill patients with COVID-19: a systematic review and meta-analysis of non-randomized cohort studies.

BACKGROUND: Although several international guidelines recommend early over late intubation of patients with severe coronavirus disease 2019 (COVID-19), this issue is still controversial. We aimed to investigate the effect (if any) of timing of intubation on clinical outcomes of critically ill patients with COVID-19 by carrying out a systematic review and meta-analysis. METHODS: PubMed and Scopus were systematically searched, while references and preprint servers were explored, for relevant articles up to December 26, 2020, to identify studies which reported on mortality and/or morbidity of patients with COVID-19 undergoing early versus late intubation. "Early" was defined as intubation within 24 h from intensive care unit (ICU) admission, while "late" as intubation at any time after 24 h of ICU admission. All-cause mortality and duration of mechanical ventilation (MV) were the primary outcomes of the meta-analysis. Pooled risk ratio (RR), pooled mean difference (MD) and 95% confidence intervals (CI) were calculated using a random effects model. The meta-analysis was registered with PROSPERO (CRD42020222147). RESULTS: A total of 12 studies, involving 8944 critically ill patients with COVID-19, were included. There was no statistically detectable difference on all-cause mortality between patients undergoing early versus late intubation (3981 deaths; 45.4% versus 39.1%; RR 1.07, 95% CI 0.99-1.15, p = 0.08). This was also the case for duration of MV (1892 patients; MD - 0.58 days, 95% CI - 3.06 to 1.89 days, p = 0.65). In a sensitivity analysis using an alternate definition of early/late intubation, intubation without versus with a prior trial of high-flow nasal cannula or noninvasive mechanical ventilation was still not associated with a statistically detectable difference on all-cause mortality (1128 deaths; 48.9% versus 42.5%; RR 1.11, 95% CI 0.99-1.25, p = 0.08). CONCLUSIONS: The synthesized evidence suggests that timing of intubation may have no effect on mortality and morbidity of critically ill patients with COVID-19. These results might justify a wait-and-see approach, which may lead to fewer intubations. Relevant guidelines may therefore need to be updated.

Effect of Early vs. Delayed or No Intubation on Clinical Outcomes of Patients With COVID-19: An Observational Study.

Background: Optimal timing of initiation of invasive mechanical ventilation in patients with acute hypoxemic respiratory failure due to COVID-19 is unknown. Thanks to early flattening of the epidemiological curve, ventilator demand in Greece was kept lower than supply throughout the pandemic, allowing for unbiased comparison of the outcomes of patients undergoing early intubation vs. delayed or no intubation. Methods: We conducted an observational study including all adult patients with laboratory-confirmed COVID-19 consecutively admitted in Evangelismos Hospital, Athens, Greece between March 11, 2020 and April 15, 2020. Patients subsequently admitted in the intensive care unit (ICU) were categorized into the "early intubation" vs. the "delayed or no intubation" group. The "delayed or no intubation" group included patients receiving non-rebreather mask for equal to or more than 24 h or high-flow nasal oxygen for any period of time or non-invasive mechanical ventilation for any period of time in an attempt to avoid intubation. The remaining intubated patients comprised the "early intubation" group. Results: During the study period, a total of 101 patients (37% female, median age 65 years) were admitted in the hospital. Fifty-nine patients (58% of the entire cohort) were exclusively hospitalized in general wards with a mortality of 3% and median length of stay of 7 days. Forty-two patients (19% female, median age 65 years) were admitted in the ICU; all with acute hypoxemic respiratory failure. Of those admitted in the ICU, 62% had at least one comorbidity and 14% were never intubated. Early intubation was not associated with higher ICU-mortality (21 vs. 33%), fewer ventilator-free days (3 vs. 2 days) or fewer ICU-free days than delayed or no intubation. Conclusions: A strategy of early intubation was not associated with worse clinical outcomes compared to delayed or no intubation. Given that early intubation may presumably reduce virus aerosolization, these results may justify further research with a randomized controlled trial.

Hospital Resources May Be an Important Aspect of Mortality Rate among Critically Ill Patients with COVID-19: The Paradigm of Greece.

For critically ill patients with coronavirus disease 2019 (COVID-19) who require intensive care unit (ICU) admission, extremely high mortality rates (even 97%) have been reported. We hypothesized that overburdened hospital resources by the extent of the pandemic rather than the disease per se might play an important role on unfavorable prognosis. We sought to determine the outcome of such patients admitted to the general ICUs of a hospital with sufficient resources. We performed a prospective observational study of adult patients with COVID-19 consecutively admitted to COVID-designated ICUs at Evangelismos Hospital, Athens, Greece. Among 50 patients, ICU and hospital mortality was 32% (16/50). Median PaO2/FiO2 was 121 mmHg (interquartile range (IQR), 86-171 mmHg) and most patients had moderate or severe acute respiratory distress syndrome (ARDS). Hospital resources may be an important aspect of mortality rates, since severely ill COVID-19 patients with moderate and severe ARDS may have understandable mortality, provided that they are admitted to general ICUs without limitations on hospital resources.

Clinical Study of Hyperglycemia and SARS-CoV-2 Infection in Intensive Care Unit Patients.

BACKGROUND/AIM: Reports indicate that coronaviridae may inhibit insulin secretion. In this report we aimed to describe the course of glycemia in critically ill patients with severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection. PATIENTS AND METHODS: We studied 36 SARS-CoV-2 patients (with no history of diabetes) in one intensive care unit (ICU). All the patients were admitted for hypoxemic respiratory failure; all but four required mechanical ventilation. The mean (±SD) age of the patients was 64.7 (9.7) years; 27 were men; the mean (±SD) duration of ICU stay was 12.9 (8.3 days). RESULTS: Twenty of 36 patients presented with hyperglycemia; brief intravenous infusions of short-acting insulin were administered in six patients. As of May 29 2020, 11 patients had died (seven with hyperglycemia). In 17 patients the Hyperglycemia Index [HGI; defined as the area under the curve of (hyper)glycemia level*time (h) divided by the total time in the ICU] was <16.21 mg/dl (0.90 mmol/l), whereas in three patients the HGI was ≥16.21 mg/dl (0.90 mol/l) and <32.25 mg/dl (1.79 mmol/l). CONCLUSION: In our series of ICU patients with SARS-CoV-2 infection, and no history of diabetes, a substantial number of patients had hyperglycemia, to a higher degree than would be expected by the stress of critical illness, lending credence to reports that speculated a tentative association between SARS-CoV-2 and hyperglycemia. This finding is important, since hyperglycemia can lead to further infectious complications.