Coagulation abnormalities were common findings in critically ill patients affected by coronavirus infection disease (COVID)-19 and often correlated to more severe illness and poor prognosis.[1] [2] [3] We recently used Rotational Thromboelastometry (ROTEM) to describe severe hypercoagulable profiles and high incidence of symptomatic venous thromboembolic (VTE) events in a small group of COVID-19 patients with acute respiratory failure admitted to intensive care unit (ICU).[4] However, it remains unclear whether COVID-19 patients with mild clinical symptoms, admitted to internal medicine wards (IMWs), present with different coagulation profiles. The primary outcome of this prospective observational study was to investigate the difference in maximum clot firmness (MCF) between IMW and ICU patients, which reflects the extent of hypercoagulability. Secondary outcome was the incidence of symptomatic VTE. The protocol was approved by the local institutional ethical committee and all consecutive patients admitted to ICU (between February 28 and April 7, 2020) and to IMW (between March 27 and April 14, 2020) for acute respiratory failure caused by SARS-CoV-2 infection were considered for enrollment ([Supplementary Material, Fig. S1], online only). Exclusion criteria were: pregnancy, preexisting bleeding or hematological disorders, acquired coagulopathies, < 18 or > 80 years of age, Child's C liver disease, severe chronic kidney disease, active cancer, and ongoing anticoagulant or antiplatelet therapies. The following EXTEM, INTEM, and FIBTEM parameters were measured: clotting time (CT, second); clot formation time (CFT, second); MCF (mm); and ThromboDynamic Index (TDI), the ratio between MCF/(CT + CFT).[5] A hypercoagulable thromboelastometry profile was defined as at least one of ROTEM assays yielding significantly higher MCF values versus healthy controls.[4] [6] Among 89 consecutive eligible patients, 25 were excluded and 64 finally enrolled ([Supplementary Fig. S1], available in the online version). Details on statistical analysis and sample size calculation are reported in [Supplementary Material S1] (available in the online version). No differences in demographic characteristics were observed between ICU and IMW patients ([Table 1]). Sequential Organ Failure Assessment score, incidence of septic shock, and the rate of infection by other respiratory pathogens were significantly higher in ICU patients. Similarly, white blood cells, neutrophils, fibrinogen, C-reactive protein, procalcitonin, ferritin, and fibrinogen levels were significantly higher ([Table 1]). About ROTEM parameters, MCF values in FIBTEM were significantly higher in ICU than in IMW patients; while CT and CFT in EXTEM were longer and TDI lower in more critically ill patients ([Table 2]). Based on the receiver operating characteristic analysis, international normalized ratio, prothrombin time, and activated partial thromboplastin time were strongly predictive of VTE among IMW patients ([Supplementary Table S1] and [Supplementary Fig. S2], available in the online version). On the contrary, lymphocytes and platelet count were highly predictive of ICU 28-day mortality ([Supplementary Table S2] and [Supplementary Fig. S3], available in the online version). Incidence of VTE, 28-day mortality, and length of hospital stay (LOHS) were significantly higher in ICU patients ([Table 1]). Twenty-one (66%) patients required invasive mechanical ventilation and showed rapid onset of symptoms and longer LOHS ([Table 1]). In these patients, CFT was prolonged and TDI in EXTEM was lower, while neutrophils and ferritin levels were significantly higher. No differences in MCF values were observed ([Table 2]). Our study showed that COVID-19 patients with mild respiratory failure admitted to IMW had less severe hypercoagulability and lower incidence of symptomatic VTE as compared with more critically ill patients. Although traditional risk factors associated with adverse outcome of ICU patients (i.e., immobility, hemodynamic instability, etc.) certainly played a fundamental role, these findings might have contributed, at least in part, to the higher 28-day mortality observed in more critically ill patients. Interestingly, traditional coagulative parameters, other than fibrinogen, were similar between ICU and IMW patients and no differences in D-dimer levels were found. These surprising findings would seem to be in contrast with those reported by other published studies.[1] [2] Nonetheless, the high standard deviation of D-dimer values that we observed, added to the relatively small sample size, may justify these differences. On the contrary, IMW patients presented with lower FIBTEM-MCF values as reflected in part by the higher fibrinogen levels observed in ICU patients. FIBTEM test, which is a better indicator of fibrin formation/polymerization and fibrinogen concentration during the acute phase, was maximally expressed in ICU patients. Notably, EXTEM-CT and EXTEM-CFT were slightly shorter and TDI higher in IMW patients, probably due to vitamin K deficiency and impaired liver synthesis and carboxylation of coagulation factors, frequently observed in ICU patients.[7] Our results showed that neither ICU nor IMW patients presented with consumptive coagulopathy (e.g., disseminated intravascular coagulation) often related to the presence of significantly elevated D-dimer levels, reduction of platelet count, prolongation of CTs, antithrombin reduction, or fibrinogen consumption.[4] [8] [9] Our results deserve some comments. Only symptomatic VTE were considered, probably underestimating the real incidence of thrombosis. This is particularly important, since IMW patients received standard thromboprophylaxis with low molecular weight heparin and ICU patients with intermediate dose in agreement with the indication of the treating physician and recent findings.[10] [11] [12] Although some protocols on the use of clinical and analytic parameters, as D-dimer levels, to manage heparin dose were recently published,[10] [11] [12] our data did not allow to assess the impact of adequate dosages of anticoagulants on clotting parameters. Moreover, whether thromboelastometry parameters can be used to monitor the correct dosing of thromboprophylaxis is still a matter of debate. The heterogeneity between ICU and IMW cohorts represents one of the main limitations to interpret our findings. Furthermore, we acknowledge that several clinical variables might have affected the differences in COVID-19-related hypercoagulable state. Moreover, the sample size, especially in the subgroup of IMW patients, could not be representative of all hospitalized COVID-19 patients. In addition, the use of thromboelastometry to assess hypercoagulability could be questioned because of the lack of standardization which can limit the comparison of data between centers. Moreover, it is well known that thromboelastometry evaluates some aspects of coagulation and clot formation but important information including platelet function or the thrombin generation potential can be missed. In conclusion, patients with life-threatening COVID-19 infection and hospitalized in ICU showed more severe hypercoagulability, higher FIBTEM-MCF values, and thrombotic risk as compared with IMW patients. The assessment of hypercoagulability through conventional coagulation tests and ROTEM could be helpful for the identification of more appropriate thromboprophylaxis strategies. Additional studies on different laboratory tests to extensively evaluate hypercoagulability in COVID-19 patients are needed. A.B., L.S., P.S., and P.N. designed the study. C.C., N.S., E.C., F.P., L.C., and M.C. collected data. L.P., A.D.C., E.P., and L.B. analyzed the data. A.B. and L.S. equally contributed to write the manuscript. P.S., P.N., E.S., A.M.C., and R.V. edited the manuscript. ^* These authors equally contributed to this work.

Background: Clinically used general anesthetics, alone or in combination, are damaging to the developing mammalian brain. In addition to causing widespread apoptotic neurodegeneration in vulnerable brain regions, exposure to general anesthesia at the peak of synaptogenesis causes learning and memory deficiencies later in life. In vivo rodent studies have suggested that activation of the intrinsic (mitochondria-dependent) apoptotic pathway is the earliest warning sign of neuronal damage, suggesting that a disturbance in mitochondrial integrity and function could be the earliest triggering events. Methods: Because proper and timely mitochondrial morphogenesis is critical for brain development, the authors examined the long-term effects of a commonly used anesthesia combination (isoflurane, nitrous oxide, and midazolam) on the regional distribution, ultrastructural properties, and electron transport chain function of mitochondria, as well as synaptic neurotransmission, in the subiculum of rat pups. Results: This anesthesia, administered at the peak of synaptogenesis, causes protracted injury to mitochondria, including significant enlargement of mitochondria (more than 30%, P < 0.05), impairment of their structural integrity, an approximately 28% increase in their complex IV activity (P < 0.05), and a twofold decrease in their regional distribution in presynaptic neuronal profiles (P < 0.05), where their presence is important for the normal development and functioning of synapses. Consequently, the authors showed that impaired mitochondrial morphogenesis is accompanied by heightened autophagic activity, decrease in mitochondrial density (approximately 27%, P < 0.05), and long-lasting disturbances in inhibitory synaptic neurotransmission. The interrelation of these phenomena remains to be established. Conclusion: Developing mitochondria are exquisitely vulnerable to general anesthesia and may be important early target of anesthesia-induced developmental neurodegeneration.

Background: General anesthetics induce apoptotic neurodegeneration in the developing mammalian brain. General anesthesia (GA) also causes significant disturbances in mitochondrial morphogenesis during intense synaptogenesis. Mitochondria are dynamic organelles that undergo remodeling via fusion and fission. The fine balance between these two opposing processes determines mitochondrial morphometric properties, allowing for their regeneration and enabling normal functioning. As mitochondria are exquisitely sensitive to anesthesia-induced damage, we examined how GA affects mitochondrial fusion/fission. Methods: Seven-day-old rat pups received anesthesia containing a sedative dose of midazolam followed by a combined nitrous oxide and isoflurane anesthesia for 6 h. Results: GA causes 30% upregulation of reactive oxygen species (n = 3–5 pups/group), accompanied by a 2-fold downregulation of an important scavenging enzyme, superoxide dismutase (n = 6 pups/group). Reactive oxygen species upregulation is associated with impaired mitochondrial fission/fusion balance, leading to excessive mitochondrial fission. The imbalance between fission and fusion is due to acute sequestration of the main fission protein, dynamin-related protein 1, from the cytoplasm to mitochondria, and its oligomerization on the outer mitochondrial membrane. These are necessary steps in the formation of the ring-like structures that are required for mitochondrial fission. The fission is further promoted by GA-induced 40% downregulation of cytosolic mitofusin-2, a protein necessary for maintaining the opposing process, mitochondrial fusion (n = 6 pups/group). Conclusions: Early exposure to GA causes acute reactive oxygen species upregulation and disturbs the fine balance between mitochondrial fission and fusion, leading to excessive fission and disturbed mitochondrial morphogenesis. These effects may play a causal role in GA-induced developmental neuroapoptosis.

The American Society of Anesthesiologists physical status (ASA-PS) is a grading system adopted worldwide by anesthesiologists to classify the overall health status of patients. Its importance is demonstrated not only by its routinely use in clinical practice, but also by its deployment in other healthcare-related environments. However, a weak/moderate inter-observer agreement for ASA-PS has been previously shown and, although definitions and clinical examples of each class were provided by ASA, doubts remain on the individual factors influencing the assignment to an ASA-PS class. The aim of this study was to investigate whether and how an anesthesiologist's experience conditions the classification into a specific ASA-PS class. An online survey presenting 8 fictitious patients was administered to a group of Italian anesthesiologists and residents of different experience. Respondents were asked to assign each one of the 8 patients to a specific ASA-PS class. For the comparisons, anesthesiologists were subdivided into 5 classes according to the experience as anesthesiologists. Six hundred one surveys were correctly completed. The highest mean number of correct answers was obtained by residents, and this number decreased progressively with increasing work experience. The lowest value was recorded in the most experienced group (≥ 20 years of experience). Low inter-reliability and experience-dependence of ASA-PS must be taken into account when evaluating a patient, particularly in settings where wide differences in experience are present.