Dynamics of disease characteristics and clinical management of critically ill COVID-19 patients over the time course of the pandemic: an analysis of the prospective, international, multicentre RISC-19-ICU registry

Background

It remains elusive how the characteristics, the course of disease, the clinical management and the outcomes of critically ill COVID-19 patients admitted to intensive care units (ICU) worldwide have changed over the course of the pandemic.

Methods

Prospective, observational registry constituted by 90 ICUs across 22 countries worldwide including patients with a laboratory-confirmed, critical presentation of COVID-19 requiring advanced organ support. Hierarchical, generalized linear mixed-effect models accounting for hospital and country variability were employed to analyse the continuous evolution of the studied variables over the pandemic.

Results

Four thousand forty-one patients were included from March 2020 to September 2021. Over this period, the age of the admitted patients (62 [95% CI 60–63] years vs 64 [62–66] years, p < 0.001) and the severity of organ dysfunction at ICU admission decreased (Sequential Organ Failure Assessment 8.2 [7.6–9.0] vs 5.8 [5.3–6.4], p < 0.001) and increased, while more female patients (26 [23–29]% vs 41 [35–48]%, p < 0.001) were admitted. The time span between symptom onset and hospitalization as well as ICU admission became longer later in the pandemic (6.7 [6.2–7.2| days vs 9.7 [8.9–10.5] days, p < 0.001). The PaO₂/FiO₂ at admission was lower (132 [123–141] mmHg vs 101 [91–113] mmHg, p < 0.001) but showed faster improvements over the initial 5 days of ICU stay in late 2021 compared to early 2020 (34 [20–48] mmHg vs 70 [41–100] mmHg, p = 0.05). The number of patients treated with steroids and tocilizumab increased, while the use of therapeutic anticoagulation presented an inverse U-shaped behaviour over the course of the pandemic. The proportion of patients treated with high-flow oxygen (5 [4–7]% vs 20 [14–29], p < 0.001) and non-invasive mechanical ventilation (14 [11–18]% vs 24 [17–33]%, p < 0.001) throughout the pandemic increased concomitant to a decrease in invasive mechanical ventilation (82 [76–86]% vs 74 [64–82]%, p < 0.001). The ICU mortality (23 [19–26]% vs 17 [12–25]%, p < 0.001) and length of stay (14 [13–16] days vs 11 [10–13] days, p < 0.001) decreased over 19 months of the pandemic.

Conclusion

Characteristics and disease course of critically ill COVID-19 patients have continuously evolved, concomitant to the clinical management, throughout the pandemic leading to a younger, less severely ill ICU population with distinctly different clinical, pulmonary and inflammatory presentations than at the onset of the pandemic.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13054-022-04065-2.

Machine learning using the extreme gradient boosting (XGBoost) algorithm predicts 5-day delta of SOFA score at ICU admission in COVID-19 patients

Background

Accurate risk stratification of critically ill patients with coronavirus disease 2019 (COVID-19) is essential for optimizing resource allocation, delivering targeted interventions, and maximizing patient survival probability. Machine learning (ML) techniques are attracting increased interest for the development of prediction models as they excel in the analysis of complex signals in data-rich environments such as critical care.

Methods

We retrieved data on patients with COVID-19 admitted to an intensive care unit (ICU) between March and October 2020 from the RIsk Stratification in COVID-19 patients in the Intensive Care Unit (RISC-19-ICU) registry. We applied the Extreme Gradient Boosting (XGBoost) algorithm to the data to predict as a binary outcome the increase or decrease in patients' Sequential Organ Failure Assessment (SOFA) score on day 5 after ICU admission. The model was iteratively cross-validated in different subsets of the study cohort.

Results

The final study population consisted of 675 patients. The XGBoost model correctly predicted a decrease in SOFA score in 320/385 (83%) critically ill COVID-19 patients, and an increase in the score in 210/290 (72%) patients. The area under the mean receiver operating characteristic curve for XGBoost was significantly higher than that for the logistic regression model (0.86 vs. 0.69, P < 0.01 [paired t-test with 95% confidence interval]).

Conclusions

The XGBoost model predicted the change in SOFA score in critically ill COVID-19 patients admitted to the ICU and can guide clinical decision support systems (CDSSs) aimed at optimizing available resources.

Hypoalbuminemia in COVID-19: assessing the hypothesis for underlying pulmonary capillary leakage

BACKGROUND

Since the first observations of patients with COVID-19, significant hypoalbuminaemia was detected. Its causes have not been investigated yet.

OBJECTIVE

We hypothesized that pulmonary capillary leakage affects the severity of respiratory failure, causing a shift of fluids and proteins through the epithelial-endothelial barrier.

METHODS

One hundred seventy-four COVID-19 patients with respiratory symptoms, 92 admitted to the intermediate medicine ward (IMW) and 82 to the intensive care unit (ICU) at Luigi Sacco Hospital in Milan, were studied.

RESULTS

Baseline characteristics at admission were considered. Proteins, interleukin 8 (IL-8) and interleukin 10 (IL-10) in bronchoalveolar lavage fluid (BALF) were analysed in 26 ICU patients. In addition, ten autopsy ultrastructural lung studies were performed in patients with COVID-19 and compared with postmortem findings in a control group (bacterial pneumonia-ARDS and H1N1-ARDS). ICU patients had lower serum albumin than IMW patients [20 (18-23) vs 28 (24-33) g L^-1 , P < 0.001]. Serum albumin was lower in more compromised groups (lower PaO₂ -to-FiO₂ ratio and worst chest X-ray findings) and was associated with 30 days of probability of survival. Protein concentration was correlated with IL-8 and IL-10 levels in BALF. Electron microscopy examinations of eight out of ten COVID-19 lung tissues showed loosening of junctional complexes, quantitatively more pronounced than in controls, and direct viral infection of type 2 pneumocytes and endothelial cells.

CONCLUSION

Hypoalbuminaemia may serve as severity marker of epithelial-endothelial damage in patients with COVID-19. There are clues that pulmonary capillary leak syndrome plays a key role in the pathogenesis of COVID-19 and might be a potential therapeutic target.

Implications of early respiratory support strategies on disease progression in critical COVID-19: a matched subanalysis of the prospective RISC-19-ICU cohort

BACKGROUND

Uncertainty about the optimal respiratory support strategies in critically ill COVID-19 patients is widespread. While the risks and benefits of noninvasive techniques versus early invasive mechanical ventilation (IMV) are intensely debated, actual evidence is lacking. We sought to assess the risks and benefits of different respiratory support strategies, employed in intensive care units during the first months of the COVID-19 pandemic on intubation and intensive care unit (ICU) mortality rates.

METHODS

Subanalysis of a prospective, multinational registry of critically ill COVID-19 patients. Patients were subclassified into standard oxygen therapy ≥10 L/min (SOT), high-flow oxygen therapy (HFNC), noninvasive positive-pressure ventilation (NIV), and early IMV, according to the respiratory support strategy employed at the day of admission to ICU. Propensity score matching was performed to ensure comparability between groups.

RESULTS

Initially, 1421 patients were assessed for possible study inclusion. Of these, 351 patients (85 SOT, 87 HFNC, 87 NIV, and 92 IMV) remained eligible for full analysis after propensity score matching. 55% of patients initially receiving noninvasive respiratory support required IMV. The intubation rate was lower in patients initially ventilated with HFNC and NIV compared to those who received SOT (SOT: 64%, HFNC: 52%, NIV: 49%, p = 0.025). Compared to the other respiratory support strategies, NIV was associated with a higher overall ICU mortality (SOT: 18%, HFNC: 20%, NIV: 37%, IMV: 25%, p = 0.016).

CONCLUSION

In this cohort of critically ill patients with COVID-19, a trial of HFNC appeared to be the most balanced initial respiratory support strategy, given the reduced intubation rate and comparable ICU mortality rate. Nonetheless, considering the uncertainty and stress associated with the COVID-19 pandemic, SOT and early IMV represented safe initial respiratory support strategies. The presented findings, in agreement with classic ARDS literature, suggest that NIV should be avoided whenever possible due to the elevated ICU mortality risk.

Lanadelumab demonstrates rapid and sustained prevention of hereditary angioedema attacks

Background

Lanadelumab demonstrated efficacy in preventing hereditary angioedema (HAE) attacks in the phase 3 HELP Study.

Objective

To assess time to onset of effect and long‐term efficacy of lanadelumab, based on exploratory findings from the HELP Study.

Methods

Eligible patients with HAE type I/II received lanadelumab 150 mg every 4 weeks (q4wks), 300 mg q4wks, 300 mg q2wks, or placebo. Ad hoc analyses evaluated day 0‐69 findings using a Poisson regression model accounting for overdispersion. Least‐squares mean monthly HAE attack rate for lanadelumab was compared with placebo. Intrapatient comparisons for days 0‐69 versus steady state (days 70‐182) used a paired t test for continuous endpoints or Kappa statistics for categorical endpoints.

Results

One hundred twenty‐five patients were randomized and treated. During days 0‐69, mean monthly attack rate was significantly lower with lanadelumab (0.41‐0.76) vs placebo (2.04), including attacks requiring acute treatment (0.33‐0.61 vs 1.66) and moderate/severe attacks (0.31‐0.48 vs 1.33, all P ≤ .001). More patients receiving lanadelumab vs placebo were attack free (37.9%‐48.1% vs 7.3%) and responders (85.7%‐100% vs 26.8%). During steady state, the efficacy of lanadelumab vs placebo was similar or improved vs days 0‐69. Intrapatient differences were significant with lanadelumab 300 mg q4wks for select outcomes. Lanadelumab efficacy was durable—HAE attack rate was consistently lower vs placebo, from the first 2 weeks of treatment through study end. Treatment emergent adverse events were comparable during days 0‐69 and 70‐182.

Conclusion

Protection with lanadelumab started from the first dose and continued throughout the entire study period.

Myocardial edema in paroxysmal permeability disorders: The paradigm of Clarkson's disease

PURPOSE

Paroxysmal Permeability Disorders (PPDs) comprise a variety of diseases characterized by recurrent and transitory increase of endothelial permeability. Idiopathic Systemic Capillary Leak Syndrome (ISCLS) is a rare PPD that leads to an abrupt massive shift of fluids and proteins from the intravascular to the interstitial compartment. In some cases, tissue edema may involve the myocardium, but its role in the development of shock has not been elucidated so far.

MATERIALS AND METHODS

Assessment of cardiac involvement during ten life-threatening ISCLS episodes admitted to ICU.

RESULTS

Transthoracic echocardiographic examination was performed in eight episodes, whereas a poor acoustic window prevented cardiac ultrasound assessment in two episodes. Myocardial edema was detected by echocardiography in eight episodes and marked pericardial effusion in one-episode. Cardiac magnetic resonance showed diffuse myocardial edema in another episode. In one case, myocardial edema caused fulminant left ventricular dysfunction, which required extracorporeal life support. The mean septum thickness was higher during the shock phase compared to the recovery phase [15.5 mm (13.1-21 mm) vs. 9.9 mm (9-11.3 mm), p = .0003]. Myocardial edema resolved within 72 h.

CONCLUSIONS

During early phases of ISCLS, myocardial edema commonly occurs and can induce transient myocardial dysfunction, potentially contributing to the pathogenesis of shock.

[Analysis of corneal and conjunctival sensitivities and its related factors of premature babies]

Objective: To analyse the corneal and conjunctival sensitivities of premature babies and to study the relevant influencing factors. Methods: Cross-sectional study. One hundred premature infants born at Women's Hospital School of Medicine Zhejiang University between May 2015 and September 2015 were enrolled, among which 51 were male (51%) and 49 were female (49%), the mean gestational age was (30.93±1.75)w, the mean corrected gestational age was (33.65±1.53)w, the mean birth weight was (1 592±336)g. The thresholds of cornea and conjunctiva of infants' left or right eyes were measured with Cochet-Bonnet aesthesiometer at 8-10 o'clock every morning when they naturally woke up, the minimum length of nylon wire that induced three successive times of eye-blink responses was recorded. Paired sample t test was used to compare the corneal and conjunctival sensitivities, the ocular surface sensitivities of preterm infants of different gender were compared using independent samples t-test, Pearson correlation and multiple linear regression analysis was conducted to analyze the correlation of corneal and conjuncitval sensitivities with gestational age, birth weight, age and corrected gestational age. Results: The mean corneal sensitivity was (44.85±5.53) mm and the mean conjunctival sensitivity was (23.50±5.48)mm in premature babies, corneal sensitivity was significantly higher than conjunctival sensitivity (t=25.620, P<0.001). No statistical significance was found between male and female preterm infants in corneal sensitivity [(44.80±5.83) mm vs. (44.90±5.25) mm, t=-0.085, P=0.933] and conjunctival sensitivity[(23.14±5.83) mm vs. (23.88±5.13) mm, t=-0.673, P=0.502]. Pearson correlation analysis showed that corneal sensitivity was significantly associated with conjunctival sensitivity in prematurity(r=0.676, P<0.001). There was significant correlation between corneal sensitivity and age, corrected gestational age (r=0.238, P=0.017; r=0.679, P<0.001), however no significant correlation was found between corneal sensitivity and gestational age, birth weight in preterm infants (r=0.067, P=0.510; r=-0.179, P=0.075). There was significant correlation between conjunctival sensitivity and corrected gestational age (r=0.490, P<0.001), however no significant correlation was found between conjunctival sensitivity and gestational age, birth weight and age in preterm infants (r=0.078, P=0.439; r=-0.096, P=0.344; r=0.151, P=0.133). Multiple linear regression revealed that corneal sensitivity(Y1) was positively correlated with corrected gestational age(X), the regression equation was Y1=2.45X-37.52, the conjunctical sensitivity(Y2) was also positively correlated with corrected gestational age(X), the regression equation was Y2=1.75X-35.41. Conclusions: The corneal sensitivity is higher than conjunctival sensitivity in premature babies.No statistical significance is found between male and female preterm infants in corneal sensitivity and conjunctival sensitivity. The corneal sensitivity and conjunctival sensitivity are correlated with corrected gestational age in preterm infants. The corneal and conjunctival sensitivities of premature babies tend to increase along with the increase of corrected gestational age. (Chin J Ophthalmol, 2018, 54: 115-119).

Primary PCI is associated with different cardiac autonomic patterns in relation to the site of myocardial infarction

AIM

Reflex alterations of cardiac autonomic modulation have been described after acute myocardial infarction (AMI). The non-homogeneous autonomic innervation of the heart gives reason of different patterns of autonomic modulation depending upon the site of AMI. Conflicting data are available on cardiac autonomic modifications after primary percutaneous coronary intervention (pPCI). We evaluated cardiac autonomic changes in patients with ST-elevation myocardial infarction (STEMI) after pPCI, either within 24h after revascularization (T0) and at clinical stability (T1, 6±2days), taking into account the site of infarction.

METHODS AND RESULTS

We enrolled 33 consecutive patients with STEMI treated with pPCI (25 males, mean age 61±12.1yr); 15 had an anterior wall STEMI (ANT) and 18 had an inferior wall STEMI (INF). ECG and respiration were recorded at T0 and at T1. Cardiac autonomic modulation was evaluated by means of symbolic analysis of heart rate variability. At T0, At T0, 0V% (marker of sympathetic modulation) was higher in INF compared to ANT [31% (18-43) vs 18% (7-32), p=0.014]. Moreover, ANT had a higher 2LV%, index of vagal modulation, compared to INF [8% (7-15) vs 5% (2-8), p=0.006].

CONCLUSION

After pPCI, these preliminary results suggest that patients with INF were characterized by a sympathetic predominance, while ANT by a predominant vagal modulation. Our data suggest that pPCI can be associated with specific autonomic patterns, which are different for ANT and INF STEMI, according to the different autonomic innervation. Future ad hoc studies are needed to confirm these preliminary observations.

Differential Diagnosis and Management Issues of Idiopathic Angiooedema and their Resolution

Angiooedema is a local and self-limiting swelling of the subcutaneous and sub mucosal tissues, produced by vasoactive peptides that temporary increase the vascular permeability. It is recognized that recurrent angiooedema exposes patients to the risk of fatalities and reduced quality of life, being in some circumstances associated with a critical condition. Angiooedema can occur with or without wheals. The first symptom is urticaria, the second is a distinct nosologic entity. In absence of an identifiable cause, recurrent angiooedema without wheals can be defined as idiopathic and marked"idiopathic histaminergic angiooedema" when it is responsive to anti histamine treatment, and "idiopathic non-histaminergic angiooedema" when it is not. Furthermore, idiopathic non-histaminergic angiooedema can be diagnosed as hereditary or sporadic by family history. In this review, we summarize the approaches to diagnose and treat different forms of idiopathic angiooedema.

Presentation, diagnosis and treatment of angioedema without wheals: a retrospective analysis of a cohort of 1058 patients

BACKGROUND

The first classification of angioedema without wheals was recently reported and comprises different forms of the disease distinguished by aetiology, mediator of oedema and inheritance.

METHODS

In total, 1725 consecutive patients with angioedema without wheals were examined at our centre between 1993 and 2012. We excluded from the analysis 667 patients because of incomplete data or because angioedema was related to a specific factor.

RESULTS

According to the new classification of angioedema, the 1058 patients included in this analysis were diagnosed with hereditary (HAE; n = 377) or acquired angioedema (AAE; n = 681). The former group included HAE with C1-inhibitor (C1-INH) deficiency (C1-INH-HAE; n = 353) and HAE with normal C1-INH levels (n = 24), of which six had a factor XII mutation (FXII-HAE) and 18 had disease of unknown origin (U-HAE). The AAE group included disease with C1-INH deficiency (C1-INH-AAE; n = 49), AAE related to angiotensin-converting enzyme inhibitor treatment (n = 183), idiopathic histaminergic (IH-AAE; n = 379) and idiopathic nonhistaminergic angioedema (InH-AAE; n = 70). We compared hereditary and AAE with uncertain aetiopathogenesis: the FXII-HAE and U-HAE groups pooled (FXII/U-HAE) versus InH-AAE. The median age at onset of FXII/U-HAE and InH-AAE was 26 and 38 years, respectively. In addition, 56% of patients with FXII/U-HAE and 81% of those with InH-AAE reported more than five attacks per year (median duration of 48 h). The location of angioedema in patients with FXII/U-HAE versus those with InH-AAE was the following: face, 70% versus 86%; tongue, oral cavity or larynx, 55% versus 68%; limbs, 70% versus 56%; and gastrointestinal mucosa, 50% versus 20%. Prophylaxis with tranexamic acid was effective in all six patients with U-HAE and in 37 of 38 with InH-AAE who were started on this treatment.

CONCLUSION

Our findings in this cohort of patients with angioedema provide new information on the clinical characteristics, diagnosis and treatment of this disease.

One night on-call: sleep deprivation affects cardiac autonomic control and inflammation in physicians

BACKGROUND

Sleep loss is associated with increased cardiovascular morbidity and mortality. It is known that chronic sleep restriction affects autonomic cardiovascular control and inflammatory response. However, scanty data are available on the effects of acute sleep deprivation (ASD) due to night shifts on the cardiovascular system and its capability to respond to stressor stimuli. The aim of our study was to investigate whether a real life model of ASD, such as "one night on-call", might alter the autonomic dynamic response to orthostatic challenge and modify the immune response in young physicians.

METHODS

Fifteen healthy residents in Internal Medicine were studied before and after one night on-call at Rest and during a gravitational stimulus (head up-tilt test, HUT). Heart rate variability (HRV), blood pressure variability (BPV) and baroreflex sensitivity (BRS) were analyzed during Rest and HUT before and after ASD. Plasmatic hormones (epinephrine, norepinephrine, cortisol, renin, aldosterone, ACTH) and tissue inflammatory cytokines were measured at baseline and after ASD.

RESULT

HRV analysis revealed a predominant sympathetic modulation and a parasympathetic withdrawal after ASD. During HUT, the sympathovagal balance shifted towards a sympathetic predominance before and after ASD. However, the magnitude of the autonomic response was lower after ASD. BPV and BRS remained unchanged before and after ASD as the hormone levels, while IFN-γ increased after ASD compared to baseline.

CONCLUSION

In summary, one night of sleep deprivation, at least in this real-life model, seems to affect cardiovascular autonomic response and immune modulation, independently by the activation of the hypothalamic-pituitary axis.

Assembly of the mitochondrial membrane system. Analysis of structural mutants of the yeast coenzyme QH2-cytochrome c reductase complex

Coenzyme QH2-cytochrome c reductase is a multisubunit complex of the mitochondrial respiratory chain. Mutants of Saccharomyces cerevisiae with lesions in cytochromes b, c1, the non-heme iron protein, and the noncatalytic subunits have been used to study several aspects of the assembly of the complex. Strains with mutations in single subunits exhibit a variety of different phenotypes. Mutants in the 17-kDa (core 3) subunit grow normally on a nonfermentable substrate indicating that this component is not essential for either enzymatic activity or assembly of the enzyme. Mutations in all the other subunits express a respiratory-deficient phenotype and the absence of detectable enzyme activity. Among the respiratory-defective strains, some have mature cytochrome b (non-heme iron protein and cytochrome c1 mutants), while other mutants lack spectrally detectable cytochrome b and have reduced levels of the apoprotein (mutants in the 44-, 40-, 14-, and 11-kDa core subunits). Mutations in single subunits exert different effects on the concentrations of their partner proteins. These may be summarized as follows: 1) No substantial loss in the 44- or 40-kDa core subunits is seen in single mutants; 2) the concentration of cytochrome c1 is also relatively unaffected by mutations in the other subunits except for the cytochrome b mutant which has 60% of the wild type level of cytochrome c1; 3) all the single mutants have only 15-20% of the normal amount of non-heme iron protein; 4) mutations in the non-heme iron protein have no appreciable effect on the concentrations of the other subunits; 5) mutations in single subunits cause parallel decreases in the concentrations of cytochrome b, the 14-, and the 11-kDa subunits. These results indicate that the synthesis or stability of a subset of subunits depends on the presence of other subunit polypeptides of the complex. At present we favor the idea that the observed changes in the concentrations of some subunits are due to higher turnover rates of the proteins in a partially assembled complex. Based on the mutant phenotypes, a tentative model for the assembly of coenzyme QH2-cytochrome c reductase is proposed. According to this model it is envisioned that the subunits interact with one another in the lipid bilayer. Maturation of apocytochrome b occurs after it is assembled with the nonstructural subunits to form a core structure. This intermediate complex interacts with the non-heme iron protein to form the active holoenzyme.

Assembly of the mitochondrial membrane system. Characterization of COR1, the structural gene for the 44-kilodalton core protein of yeast coenzyme QH2-cytochrome c reductase

The respiratory deficiency of yeast strains previously assigned to complementation group G7 has been ascribed to the absence in the mutants of functional cytochrome b. Since G7 mutants are capable of synthesizing the apoprotein, the primary effect of the mutations is to prevent maturation of this electron carrier. The recombinant plasmid pG7/T1 with a 6.7-kilobase pairs (kb) insert of wild type yeast nuclear DNA has been selected from a genomic library by transformation of a G7 mutant to respiratory competency. The genetically active region of the pG7/T1 insert has been subcloned on a 3-kb fragment of DNA which has been shown to contain an open reading frame encoding a protein of 50,236 Mr. In situ disruption of the reading frame causes a deficiency in cytochrome b. The strain with the disrupted gene fails to complement G7 mutants thereby confirming the correct identification of the gene henceforth referred to as COR1. The carboxyl-terminal half of the COR1 gene has been fused to the amino-terminal half of the Escherichia coli trpE gene in the high expression vector pATH2. This plasmid construct promotes a high level of expression of the trpE/COR1 hybrid protein. Antibodies against the purified hybrid protein react with a 44 kDa protein subunit of yeast coenzyme QH2-cytochrome c reductase corresponding to the largest core subunit of the complex. These data indicate that the yeast nuclear gene COR1 codes for the 44-kDa core protein and that the latter is required for the conversion of apocytochrome b to mature cytochrome b.