A randomized, open-label, adaptive, proof-of-concept clinical trial of modulation of host thromboinflammatory response in patients with COVID-19: the DAWn-Antico study.

BACKGROUND: The peak of the global COVID-19 pandemic has not yet been reached, and many countries face the prospect of a second wave of infections before effective vaccinations will be available. After an initial phase of viral replication, some patients develop a second illness phase in which the host thrombotic and inflammatory responses seem to drive complications. Severe COVID-19 disease is linked to high mortality, hyperinflammation, and a remarkably high incidence of thrombotic events. We hypothesize a crucial pathophysiological role for the contact pathway of coagulation and the kallikrein-bradykinin pathway. Therefore, drugs that modulate this excessive thromboinflammatory response should be investigated in severe COVID-19. METHODS: In this adaptive, open-label multicenter randomized clinical trial, we compare low molecular weight heparins at 50 IU anti-Xa/kg twice daily-or 75 IU anti-Xa twice daily for intensive care (ICU) patients-in combination with aprotinin to standard thromboprophylaxis in hospitalized COVID-19 patients. In the case of hyperinflammation, the interleukin-1 receptor antagonist anakinra will be added on top of the drugs in the interventional arm. In a pilot phase, the effect of the intervention on thrombotic markers (D-dimer) will be assessed. In the full trial, the primary outcome is defined as the effect of the interventional drugs on clinical status as defined by the WHO ordinal scale for clinical improvement. DISCUSSION: In this trial, we target the thromboinflammatory response at multiple levels. We intensify the dose of low molecular weight heparins to reduce thrombotic complications. Aprotinin is a potent kallikrein pathway inhibitor that reduces fibrinolysis, activation of the contact pathway of coagulation, and local inflammatory response. Additionally, aprotinin has shown in vitro inhibitory effects on SARS-CoV-2 cellular entry. Because the excessive thromboinflammatory response is one of the most adverse prognostic factors in COVID-19, we will add anakinra, a recombinant interleukin-1 receptor antagonist, to the regimen in case of severely increased inflammatory parameters. This way, we hope to modulate the systemic response to SARS-CoV-2 and avoid disease progressions with a potentially fatal outcome. TRIAL REGISTRATION: The EU Clinical Trials Register 2020-001739-28 . Registered on April 10, 2020.

Delayed and prolonged coma after acute disulfiram overdose.

We report the case of a 35-year-old man presenting with a delayed and prolonged coma due to an intentional overdose with disulfiram without simultaneous alcohol ingestion. The clinical features--comprising a severe toxic encephalopathy with coma and convulsions, in combination with a quadriparesis outlasting the loss of consciousness--are summarized, and the physiopathology is reviewed.

The histopathological spectrum of malignant hyperthermia and rhabdomyolysis due to RYR1 mutations.

OBJECTIVE: The histopathological features of malignant hyperthermia (MH) and non-anaesthetic (mostly exertional) rhabdomyolysis (RM) due to RYR1 mutations have only been reported in a few cases. METHODS: We performed a retrospective multi-centre cohort study focussing on the histopathological features of patients with MH or RM due to RYR1 mutations (1987-2017). All muscle biopsies were reviewed by a neuromuscular pathologist. Additional morphometric and electron microscopic analysis were performed where possible. RESULTS: Through the six participating centres we identified 50 patients from 46 families, including patients with MH (n = 31) and RM (n = 19). Overall, the biopsy of 90% of patients showed one or more myopathic features including: increased fibre size variability (n = 44), increase in the number of fibres with internal nuclei (n = 30), and type I fibre predominance (n = 13). Abnormalities on oxidative staining, generally considered to be more specifically associated with RYR1-related congenital myopathies, were observed in 52%, and included unevenness (n = 24), central cores (n = 7) and multi-minicores (n = 3). Apart from oxidative staining abnormalities more frequently observed in MH patients, the histopathological spectrum was similar between the two groups. There was no correlation between the presence of cores and the occurrence of clinically detectable weakness or presence of (likely) pathogenic variants. CONCLUSIONS: Patients with RYR1-related MH and RM exhibit a similar histopathological spectrum, ranging from mild myopathic changes to cores and other features typical of RYR1-related congenital myopathies. Suggestive histopathological features may support RYR1 involvement, also in cases where the in vitro contracture test is not informative.

Molecular genetic detection of susceptibility to malignant hyperthermia in Belgian families.

Malignant hyperthermia is an autosomal dominant myopathy triggered by volatile anesthetics or succinylcholine in susceptible persons. While in vitro contracture testing (IVCT) is the gold standard to establish malignant hyperthermia (MH) susceptibility, genetic analysis is increasingly used to diagnose this condition. This work aimed to determine the frequency and distribution of ryanodine receptor (RYR1) mutations in the Belgian MH-population as investigated by IVCT in our centre, as well as the discordance rates between the 2 techniques. Sequence analysis of 16 RYRI-exons in 29 selected families resulted in the detection of 10 mutations (4 Gly341Arg, 2 Arg614Leu, and 1 Cys35Arg, Arg614Cys, Arg2163Cys and Arg2435His). Discordance between IVCT and mutation analysis was observed in only 6 out of 96 individuals from 4 different families. No mutation-positive/ IVCT-negative diagnosis was found. Genetic evaluation of RYR1-mutations can secure a diagnosis and aid in genetic counselling of individual family members but only in those families in which significant clinical information is present, as well as phenotyping by IVCT has been realized.

A survey of obstetric an aesthesia practice in Flanders.

The use of locoregional anaesthesia in obstetrics in Flanders was assessed by a postal questionnaire sent to the directors of the anaesthesia departments of the 72 hospitals with an obstetric unit. 59 (82%) answers were returned. In the group of parturients who had a vaginal delivery a neuraxial technique was requested by 65% of the patients and consisted of epidural analgesia in 84%, and combined spinal epidural analgesia in 16%. Test doses are used in labour in 67%. To perform the block--spinal as well as epidural--the sitting position is somewhat preferred over the left lateral (55 versus 45%). For caesarean section general anaesthesia was used in only 5% of the deliveries, whereas spinal, single or as a part of a CSE technique, was preferred in 80%; the epidural technique was applied in 15%. There is no clear preference in technique for postoperative analgesia after caesarean delivery as both parenteral and epidural analgesia are used in 50% of the cases.

The changing face of malignant hyperthermia: less fulminant, more insidious..

Modern anaesthetic techniques have resulted in the clinical presentation of malignant hyperthermia to be more often indolent and/or insidious than truly fulminant, as previously known in the anaesthetic community. We present four recently referred cases to illustrate this point: one late-onset case, two patients with slowly progressive hypercapnia as the sole sign and a fourth patient with postoperative myalgias and elevated creatine kinase. We also discuss the reasons for the shift in typical clinical presentation. The more insidious character of malignant hyperthermia is most likely due to the lower triggering potency of modern volatile anaesthetics, the mitigating effects of several intravenous drugs (neuromuscular blocking agents, alpha 2 adrenergic receptor agonists, beta adrenergic blockade) or techniques (neuraxial anaesthesia) and the routine use of end-tidal CO2 monitoring leading to the early withdrawal of triggering drugs. Awareness among anaesthetists of this change in presentation is important since the clinical diagnosis is often more doubtful and, if corroborative evidence is not sought, the diagnosis may be delayed or missed altogether.

Compound RYR1 heterozygosity resulting in a complex phenotype of malignant hyperthermia susceptibility and a core myopathy.

Malignant hyperthermia (MH) is a potentially fatal pharmacogenetic myopathy triggered by exposure to volatile anesthetics and/or depolarizing muscle relaxants. Susceptibility to MH is primarily associated with dominant mutations in the ryanodine receptor type 1 gene (RYR1). Recent genetic studies have shown that RYR1 variants are the most common cause of dominant and recessive congenital myopathies - central core and multi-minicore disease, congenital fiber type disproportion, and centronuclear myopathy. However, the MH status of many patients, especially with recessive RYR1-related myopathies, remains uncertain. We report the occurrence of a triplet of RYR1 variants, c.4711A>G (p.Ile1571Val), c.10097G>A (p.Arg3366His), c.11798A>G (p.Tyr3933Cys), found in cis in four unrelated families, one from Belgium, one from The Netherlands and two from Canada. Phenotype-genotype correlation analysis indicates that the presence of the triplet allele alone confers susceptibility to MH, and that the presence of this allele in a compound heterozygous state with the MH-associated RYR1 variant c.14545G>A (p.Val4849Ile) results in the MH susceptibility phenotype and a congenital myopathy with cores and rods. Our study underlines the notion that assigning pathogenicity to individual RYR1 variants or combination of variants, and counseling in RYR1-related myopathies may require integration of clinical, histopathological, in vitro contracture testing, MRI and genetic findings.

Recent advances in the diagnosis of malignant hyperthermia susceptibility: how confident can we be of genetic testing?

Malignant hyperthermia (MH) is a condition that manifests in susceptible individuals only on exposure to certain anaesthetic agents. Although genetically heterogeneous, mutations in the RYR1 gene (19q13.1) are associated with the majority of reported MH cases. Guidelines for the genetic diagnosis for MH susceptibility have recently been introduced by the European MH Group (EMHG). These are designed to supplement the muscle biopsy testing procedure, the in vitro contracture test (IVCT), which has been the only means of patient screening for the last 30 years and which remains the method for definitive diagnosis in suspected probands. Discordance observed in some families between IVCT phenotype and susceptibility locus genotype could limit the confidence in genetic diagnosis. We have therefore assessed the prevalence of 15 RYR1 mutations currently used in the genetic diagnosis of MH in a sample of over 500 unrelated European MH susceptible individuals and have recorded the frequency of RYR1 genotype/IVCT phenotype discordance. RYR1 mutations were detected in up to approximately 30% of families investigated. Phenotype/genotype discordance in a single individual was observed in 10 out of 196 mutation-positive families. In five families a mutation-positive/IVCT-negative individual was observed, and in the other five families a mutation-negative/IVCT-positive individual was observed. These data represent the most comprehensive assessment of RYR1 mutation prevalence and genotype/phenotype correlation analysis and highlight the possible limitations of MH screening methods. The implications for genetic diagnosis are discussed.

Haemodynamic monitoring. Problems, pitfalls and practical solutions.

The synthesis of adenosine triphosphate (ATP) depends on the coordinated interaction of oxygen delivery and glucose breakdown in the Krebs cycle. Cellular oxygen depots are non-existent, therefore the peripheral cells are totally dependent on the circulation for sufficient oxygen delivery. Shock is the clinical manifestation of cellular oxygen craving. The commonly measured variables--blood pressure, heart rate, urinary output, cardiac output and systemic vascular resistance--are not sensitive or accurate enough to warn of impending death in acutely ill patients nor are they appropriate for monitoring therapy. Calculated oxygen transport and oxygen consumption parameters provide the best available measures of functional adequacy of both circulation and metabolism. In order to optimise oxygen delivery (DO2), 4 interacting factors must be taken into account: cardiac output, blood haemoglobin content, haemoglobin oxygen saturation and avidity of oxygen binding to haemoglobin. For viscosity reasons, the optimal haemoglobin concentration is in the vicinity of 90 to 100 g/L, but for optimising the oxygen transport 100 to 115 g/L or a haematocrit of 30 to 35% seems better. The p50 (the pO2 at which haemoglobin is 50% saturated) describes the oxygen-haemoglobin dissociation curve; normally its value is +/- 27 mm Hg. It can be influenced by attaining normal body temperature, pH, pCO2 and serum phosphorous levels. In order to obtain an arterial blood saturation (SaO2) of more than 90% with acceptable haemodynamics, the ventilation mode and inspired oxygen fraction (FiO2) must be adapted; care must be taken not to stress the labile circulation with haemodynamic compromising ventilation techniques [e.g. high positive end expiratory pressure (PEEP) levels, inverse-ratio ventilation, etc.]. The factor most amenable to manipulation is the cardiac output, with its 4 determinants--preload, afterload, contractility and heart rate. In daily clinical practice, heart rate should be between 80 and 120 beats/min; small variations are acceptable. Important deviations must be treated by chemically [isoprenaline (isoproterenol)] or electrically (pacing techniques) accelerating the heart, or with the different antiarrhythmic drugs. A wide variety of agents is available to decrease the preload: diuretics [especially furosemide (frusemide)], venodilators like nitroglycerin (glyceryl trinitrate), isosorbide dinitrate (sorbide nitrate) and sodium nitroprusside, ACE inhibitors, phlebotomy, and haemofiltration techniques (peritoneal or haemodialysis, continuous arteriovenous haemofiltration). To increase the preload, volume loading using a rigid protocol ('rule of 7 and 3'), preferably with colloids, or vasopressor agents [norepinephrine (noradrenaline), epinephrine (adrenaline), dopamine] are useful. Arterial vasopressors are needed to improve perfusion pressure of 'critical' (coronary and cerebral) arteries. Afterload can be decreased by arterial vasodilators. Predominantly arterial dilators are hydralazine and clonidine, while sodium nitroprusside, nitroglycerin and isosorbide dinitrate have combined arterial and venous dilating actions.(ABSTRACT TRUNCATED AT 400 WORDS)

The influence of labetalol on arterial blood gas data, pulmonary haemodynamics and pulmonary shunting.

The arterial oxygen and carbon dioxide tensions, pulmonary and systemic haemodynamics and pulmonary shunting and mechanics were measured during the first 30 min after intravenous labetalol administration. Thirty patients, recovering in the intensive care unit after neurosurgical interventions were randomly divided in 2 groups of 15 patients, receiving either labetalol or placebo. In the labetalol treated group the arterial oxygen tension decreased from 553.6 +/- 16.8 to 529.3 +/- 19.8 mmHg 5 min after the injection of labetalol. A concomitant increase in arterial carbon dioxide tension from 40.1 +/- 1.1 to 45.5 +/- 1.3 mmHg was noticed. Pulmonary vascular resistance decreased from 159.6 +/- 14.7 to 116.7 +/- 11.7 dynes.sec.cm-5 and pulmonary shunting increased from 4.8% +/- 1.4% to 8.1% +/- 2.4% 5 min following injection. All these changes were statistically significant for p less than 0.01. After 30 min all values had returned to their initial level. No changes were registered in the control group. As airway resistance appeared not to be affected by the labetalol administration it may be concluded that the observed changes in blood gas data are most likely due to a transient decrease of the pulmonary vascular resistance with a concomitant increase in pulmonary shunting.

Acute poisoning with amphetamines (MDEA) and heroin: antagonistic effects between the two drugs.

A case of oral ingestion of large doses of both the amphetamine-derivative 3,4-methylene dioxyethamphetamine (MDEA) and heroin is reported. Despite high serum levels of both drugs, the patient did not present with the classic signs and symptoms normally seen during intoxication with these drugs. The patient recovered after symptomatic treatment. The possibility that opposite pharmacological properties of the two drugs prevented the patients death is discussed.

Slower recovery of muscle phosphocreatine in malignant hyperthermia-susceptible individuals assessed by 31P-MR spectroscopy.

Our aim was to develop an exercise protocol using 31P-magnetic resonance spectroscopy (31P-MRS), which can discriminate between malignant hyperthermia-susceptible (MHS) individuals and controls. MRS spectra of the forearm muscles were recorded at rest, during and after a standardized exercise protocol in 10 MHS patients and compared with spectra obtained in 10 controls. There was no difference in resting intracellular pH (pHi) or PCr/(Pi+PCr) ratio between the groups (PCr = phosphocreatine, Pi = inorganic phosphorus). At the end of the exercise and during the initial recovery phase, the pHi and PCr/(Pi+PCr) ratio were significantly lower in the MHS group ([pHi: 6.37 (0.07) for MHS vs 6.70 (0.05) for controls, P < 0.005; PCr/(Pi+PCr): 0.784 (0.017) for MHS vs 0.954 (0.020) for controls, P < 0.0005]). For PCr/(Pi+PCr), complete separation between the two groups was observed during the initial recovery phase. The mean recovery time of PCr/(Pi+PCr) was 0.57 min for the control group and 1.28 min for the MHS group. The slower recovery of PCr/(Pi+PCr) is likely to be caused by a combination of several factors, including the lower pHi in MHS subjects at the start of recovery (inhibiting ATP production) and excessive sarcoplasmic calcium overload (causing continued enzyme activation and ATP consumption). Our exercise protocol can be a valuable adjunct to discriminate between MHS and non susceptible subjects.

Malignant hyperthermia susceptibility in a patient with concomitant motor neuron disease.

Laboratory confirmation of a clinical suspicion of malignant hyperthermia (MH) susceptibility by the standard in vitro contracture test remains inconclusive in patients reacting only to caffeine or halothane (called 'Equivocal') or in patients with concomitant neuromuscular disease. The detection of point mutations in the ryanodine receptor gene potentially provides additional information in these cases. The diagnostic value of the Gly341 Arg mutation in a patient reacting in vitro only to caffeine was reported previously by Quane et al. (1994). The present report describes a patient with motor neuron disease carrying the Gly341 Arg mutation, expanding the diagnostic value of this mutation to the group of patients with neuromuscular diseases.

Gly341Arg mutation indicating malignant hyperthermia susceptibility: specific cause of chronically elevated serum creatine kinase activity.

We report on three families with the Gly341Arg ryanodine receptor gene (RYR1) mutation. Thirteen individuals were heterozygote carriers of the Gly341Arg mutation and had clearly positive in vitro contracture tests, indicating malignant hyperthermia susceptibility. Nine Gly341Arg mutation positive individuals from two families had elevated serum creatine kinase (CK) activity at rest (up to six times the normal upper limit). Their clinical and neurological examinations as well as detailed muscle histology were normal. The third family did not show increased CK activity. These findings indicate that the Gly341Arg mutation can be a specific cause of chronically elevated serum CK activity in asymptomatic individuals.

Lazarus sign and extensor posturing in a brain-dead patient. Case report.

A man was declared brain dead after having sustained a gunshot wound to the head. All clinical criteria for the diagnosis of brain death were met. The electroencephalogram was isoelectric, and four-vessel angiography demonstrated the absence of cerebral blood flow. However, stereotypic spontaneous movements were observed which persisted for several hours. The possible mechanism is discussed and a short review of the literature is given.

Discordant light microscopic, electron microscopic, and in vitro contracture study findings in a family with central core disease.

We report a family that was referred to our laboratory after a fatal malignant hyperthermia (MH) accident during general anesthesia. Postmortem study of different muscles of the proband pointed retrospectively to the presence of central core disease (CCD). Of the 8 family members investigated by histology and in vitro contracture testing (IVCT) 5 were found to be MH-susceptible. Neurological examination was completely normal. Histologically, these 5 patients showed a highly variable proportion (6-89%) of cores in type 1 fibers on light microscopy. In 3 patients definite central cores were found, in 1 patient multicore disease was diagnosed, and 1 patients presented with a mixed central/paracentral form. Electron microscopy could detect cores in only 4 out of 5 patients. These results demonstrate the difficulty to diagnose central or multicore disease and suggest that mixed forms within the same family may occur. The one histologically dubious patient in this family shows that the most sensitive test for the diagnosis of this myopathy might be the IVCT.

An image analysis study of vastus lateralis muscle fibers in malignant hyperthermia susceptible patients.

We studied the correlation between the in vitro contracture test (IVCT) performed in malignant hyperthermia (MH) and the muscle fiber type composition in 29 human vastus lateralis (VL) biopsy samples (from 12 women and 17 men) using a semiautomated image analyzer. Relative number, lesser diameter, global area, and spatial distribution of the muscle fibers were measured. In these and in 26 additional VL muscle biopsy samples of patients with other myopathies, we compared our morphometric data with the observations made by the pathologist. Among the MH group, type 1 fibers were larger in both malignant hyperthermia susceptible (MHS) men and women reaching statistical significance only in the latter. The relative number and global area were unchanged. In MHS patients relative number and global area of type 2A fibers were smaller. No changes in the parameters of type 2B fibers were found. In a minority of sections (14%) clustering was observed. Sex-related alterations in type 2 fiber characteristics were found between MHS patients. However, our findings do not clearly point towards a syndrome-induced alteration of size, number, global area, or distribution of type 1, 2A, and 2B muscle fibers in VL of MH patients. By morphometric analysis, we found several additional biopsy samples that met the interpretation of "abnormal" size and number of muscle fibers in human malignant hyperthermia than were reported by the pathologist.

Differential diagnosis of anesthesia induced rhabdomyolysis. A case report.

A four year old boy suffered from a prolonged cardiac arrest during anesthesia. Laboratory examination subsequently demonstrated extensive rhabdomyolysis. The possibility of an underlying muscle disease in this family was investigated by muscle biopsy, histological examination and in-vitro contracture testing. The latter test result was consistent with malignant hyperthermia susceptibility. This case history illustrates the differential diagnosis of anesthesia induced rhabdomyolysis.

Transcranial Doppler sonography in subarachnoid hemorrhage.

Ten patients presenting a subarachnoid hemorrhage (SAH) due to rupture of a middle cerebral or an anterior communicating aneurysm are presented. Transcranial Doppler (TCD) values are obtained at different time intervals after SAH. The correlation of TCD values, vasospasm and clinical course is discussed.