D-dimer levels for Risk Stratification in Patients with Suspected COVID-19 - A Prospective Observational Study

BACKGROUND

Elevated D-dimer levels have been observed in COVID-19 and are of prognostic value, but have not been compared to an appropriate control group.

METHODS

Observational cohort study including emergency patients with suspected or confirmed COVID-19. Logistic regression defined the association of D-dimer levels, COVID-19 positivity, age, and gender with 30-day-mortality.

RESULTS

953 consecutive patients (median age 58, 43% women) presented with suspected COVID-19: 12 (7.4%) patients with confirmed SARS-CoV-2-infection died, compared with 28 (3.5%) patients without SARS-CoV-2-infection. Overall, most (56%) patients had elevated D-dimer levels (≥0.5mg/l). Age (OR 1.07, CI 1.05-1.10), D-dimer levels ≥0.5mg/l (OR 2.44, CI 0.98-7.39), and COVID-19 (OR 2.79, CI 1.28-5.80) were associated with 30-day-mortality.

CONCLUSION

D-dimer levels are effective prognosticators in both patient groups.

Nutritive characteristics of perennial ryegrass cultivars: have they changed over time?

Improvement in nutritive characteristics resulting from breeding perennial ryegrass (PRG) cultivars used in Australia from the 1970s to the present day was quantified in a grazed field experiment in south-western Victoria. The experiment was sown in May 2014 with measurements undertaken over 3 years. The experiment contained 36 PRG treatments (cultivar–endophyte combinations), which were replicated four times, with herbage nutritive characteristics measured at each grazing. The treatments differed in estimated metabolisable energy (ME), crude protein and neutral detergent fibre (NDF) concentrations at each harvest date. The decade of cultivar release had little effect on the ME or the NDF concentration of the cultivars released from 1970s onward. Early season diploids had a lower ME concentration than did later-maturing diploid cultivars (11.0 vs 11.4 MJ/kg DM), predominantly due to a lower ME concentration in late spring and early summer (10.3 vs 11.1 MJ/kg DM). The tetraploid cultivars had a higher ME concentration (11.8 vs 11.4 MJ/kg DM) and a lower NDF (480 vs 505 g/kg DM) concentration than did the mid- and late-season diploid cultivars. These differences are likely to be of economic importance at the farm level.

P2532Incidence and outcome of perioperative myocardial infarction/injury after non-cardiac surgeries diagnosed by high-sensitivity cardiac troponin I

Background

In order to differentiate perioperative myocardial infarction/injury (PMI) after non-cardiac surgery from preexisting cardiomyocyte injury from chronic disorders, recent studies have shown the importance of using an acute absolute increase as a criterion for PMI. For high-sensitivity troponin T (hs-cTnT), PMI defined as an absolute increase of 14ng/L (the 99th percentile) has been shown to be strongly associated with 30-day mortality. Until now, no data on hs-cTnI are available. This is a major unmet clinical need, as relevant differences between hs-cTnT and hs-cTnI have recently been identified and, as worldwide hs-cTnI is more commonly used as compared to hs-cTnT. We hypothesized that applying the same criterion to hs-cTnI, would reveal a similar association with outcomes.

Purpose

To evaluate the incidence and outcome of PMI diagnosed by hs-cTnI after non-cardiac surgery.

Methods

We included prospectively consecutive high cardiovascular risk patients undergoing non-cardiac surgery. Hs-cTnI concentrations were measured before surgery and, daily after surgery, for three days. PMI was defined as an absolute rise of ≥26ng/L (the 99th percentile of the assay studied) from baseline values. The primary outcome was major adverse cardiovascular events (MACE), a composite of cardiovascular death, myocardial infarction, acute heart failure and arrhythmias, and the secondary outcome was all-cause mortality, within 30 days and one year.

Results

We included 2,018 patients submitted to 2,551 surgeries. Patients had median age of 73 years (IQR 68–79) and 56% were male. After surgery, 231 patients (9%, 95% CI 8–10%) fulfilled PMI diagnostic criterion. Patients with PMI had higher rates of MACE than patients without PMI, at 30 days (13% vs. 2%; P<0.001) and, at one-year follow-up (25% vs. 8%; P<0.001). All-cause mortality was also higher in PMI patients within 30 days and one year (9% vs. 1.5% and, 22% vs. 8%, respectively; P<0.001). In multivariate cox regression analysis, PMI showed a hazard ratio (HR) of 4.7 (95% CI, 2.9–7.6; P<0.001) within 30 days, and a HR of 2.7 (95% CI, 2.0–3.7; P<0.001) within one year for the occurrence of MACE. For total mortality, PMI showed a HR of 3.8 (95% CI, 2.1–6.8; P<0.001) within 30 days and a HR of 2.0 (95% CI, 1.4–2.7; P<0.001) after one year.

Conclusion

PMI is frequent and associated with high rates of MACE and mortality in short- and long-term follow-up after non-cardiac surgery, regardless of the high-sensitivity troponin assay used for diagnosis.

Acknowledgement/Funding

Swiss Heart Foundation, University basel, Abbott, Astra zeneca, Forschungsfond Kantonsspital Aarau, Cardiovascular Research Foundation Basel, FAPESP

Intrapleural topical application of cisplatin with the surgical carrier Vivostat increases the local drug concentration in an immune-competent rat model with malignant pleuromesothelioma

OBJECTIVE

We sought to investigate whether intrapleural topical application of cisplatin with a surgical carrier has a prolonged local tissue level in comparison with cisplatin solution while reducing systemic toxicity.

METHODS

Forty immune-competent Fischer rats were inoculated with 10(6) mesothelioma cells. Ten days later, left pneumonectomy with tumor debulking was performed. Twenty animals underwent local application of cisplatin solution (100 mg/m2), whereas the same quantity of cisplatin was topically applied as a gel with the Vivostat (Vivolution) system in 20 other animals. In each group 5 subgroups of 4 animals were defined according to the harvesting time of blood and tissue samples (2, 4, 24, and 72 hours and 1 week) after local therapy. Platinum concentrations in serum and tissue and systemic toxicity were analyzed.

RESULTS

Platinum concentrations in tissue were significantly higher in the gel group (group 1) than in the solution group (group 2) at 1, 3, and 7 days after therapy (1510, 1224, and 1069 pg/mg for group 1 vs 598, 382, and 287 pg/mg for group 2; P = .007, P = .005, and P = .0002, respectively). Laboratory findings showed renal insufficiency in the animals of the solution group at 1 week, with values of 98 mmol/L versus 7.7 mmol/L for urea and 410 mumol/L versus 43 mumol/L for creatinine (P = .02 and P = .01, respectively), which was confirmed by means of pathologic analysis.

CONCLUSIONS

Intrapleural administration of cisplatin with the carrier Vivostat significantly provides sustained higher platinum concentrations up to 1 week in tissue in comparison with application of cisplatin solution without conferring systemic toxicity in this model.

Concentration of rocuronium in cerebrospinal fluid of patients undergoing cerebral aneurysm clipping †

BACKGROUND

This study assessed the concentration of rocuronium in the cerebrospinal fluid (CSF) of patients undergoing cerebral aneurysm clipping, and investigated whether the mode of administration (single bolus vs continuous infusion) influenced the CSF concentration.

METHODS

Twenty patients with subarachnoid haemorrhage were randomly allocated to receive a bolus dose (bolus group), or a bolus followed by a continuous infusion of rocuronium (infusion group) (n=10 for each group). Arterial blood and ventricular CSF were sampled 2 h after the rocuronium bolus. Samples were analysed by liquid chromatography electrospray ionization-tandem mass spectrometry.

RESULTS

Rocuronium could be detected in all the CSF samples. The mean (range) CSF concentration was 2.2 (0.9-4.6) ng x ml(-1) in the bolus group and 12.4 (2.4-34.6) ng x ml(-1) in the infusion group; P<0.01.

CONCLUSIONS

This study demonstrated that rocuronium, normally not considered to cross the blood-brain barrier, is regularly found in the CSF of patients undergoing cerebral clipping; continuous infusion of the drug led to higher plasma and CSF concentrations than after a single bolus dose.

Different patterns of mast cell activation by muscle relaxants in human skin

BACKGROUND

Activation of mast cells and systemic release of histamine are major side effects of intravenously administered muscle relaxants. In the current study, dermal microdialysis was used for the investigation of mast cell activation by muscle relaxants. Dermal microdialysis enabled simultaneous assessment of mediator release, vascular reactions, and sensory effects induced by intradermal application of muscle relaxants without systemic side effects.

METHODS

Succinylcholine, the isoquinolines cisatracurium, atracurium, and mivacurium, and the steroids pancuronium, vecuronium, rocuronium, and rapacuronium were tested in human volunteers (n = 6 each). After intradermal insertion of microdialysis capillaries (0.4 mm diameter, cutoff 3,000 kd) and a 60-min equilibration period, the muscle relaxants were delivered via the capillaries for 30 min, followed by a 30-min washout period. Dialysate was sampled at 15-min intervals, and histamine, mast cell tryptase, and protein extravasation were determined. Changes in skin blood flow were measured using a laser Doppler imager. Potency and efficacy were derived from nonlinear fittings of the dose-response curves.

RESULTS

For succinylcholine and the isoquinolines, dose-response curves for the vascular and sensory effects paralleled the histamine and tryptase release. In contrast, aminosteroids evoked a rapid histamine release that was accompanied by a delayed increase in tryptase.

CONCLUSIONS

Dermal microdialysis has been successfully used to simultaneously assess mediator release, vascular reactions, and sensory effects. The different pattern of tryptase release by isoquinolines and aminosteroids suggests different mechanisms of mast cell activation.

[Fatal brain edema after ingestion of ecstasy and benzylpiperazine]

HISTORY AND ADMISSION FINDINGS

A 23-year-old woman was hospitalized with headache, malaise and somnolence 11 hours after ingestion of A2 (benzylpiperazine), 7 hours after ingestion of ecstasy (MDMA), and large volume of fluids. On admission she had bradycardia (heart rate 48/min), hypertension (blood pressure 154/95 mm Hg), and reduced consciousness with diminished tendon reflexes and non-reacting pupils (Glasgow Coma Score 6).

INVESTIGATIONS

Serum sodium was markedly decreased (115 mmol/l [normal 135-145]) with low plasma osmolality (246 mosm/kg [normal 280-300]). Other laboratory findings were within normal limits.

TREATMENT AND COURSE

The patient had severe hypervolaemic hypotonic hyponatraemia. 40 minutes after admission she seized twice and was intubated. Brain CT scan showed massive cerebral oedema with beginning tonsillar herniation. Serum sodium concentration returned to normal within 38 hours, but the patient deteriorated neurologically with increasing tonsillar herniation detected in a second brain CT scan. The patient died 57 hours after admission.

CONCLUSION

13 cases of MDMA-associated severe hyponatraemia are reported. Intake of fluids after MDMA ingestion may lead to potentially fatal hypervolaemic hypotonic hyponatraemia with cerebral oedema. Symptoms appear about 8 hours (range 4-18) after MDMA ingestion. Even low doses of MDMA and fluids may lead to a serious outcome. The only risk factor is female gender. Measurement of serum sodium and brain CT scan is recommended in all patients with altered mental status after MDMA consumption.

Rapid detection of the CYP2D6*3, CYP2D6*4, and CYP2D6*6 alleles by tetra-primer PCR and of the CYP2D6*5 allele by multiplex long PCR

BACKGROUND

Interindividual differences in CYP2D6 activity range from total absence of metabolism of certain drugs to ultrafast metabolism and can produce adverse effects or lack of therapeutic effect under standard therapy. Several mutations have been described in the CYP2D6 gene that abolish CYP2D6 activity. However, four mutations explain the majority of the poor metabolizers. We describe four single-tube assays to detect these mutations.

METHODS

Three tetra-primer PCR assays were developed to detect the mutations in the CYP2D6*3, *4, and *6 alleles. In these single-tube assays, the CYP2D6 locus is amplified directly, followed by the allele-specific amplification on this new template. In addition, a multiplex long PCR was developed to genotype the CYP2D6*5 allele. Two long PCR amplifications for detection of the deletion of CYP2D6 (*5) and for detection of the CYP2D6 gene region were combined in one tube.

RESULTS

Analysis of 114 alleles showed no CYP2D6*3 allele, and allele frequencies of 28.1% for CYP2D6*4, 2.6% for CYP2D6*5, and 0. 9% for CYP2D6*6. Re-analysis of the DNA samples by restriction fragment length polymorphism and sequencing analysis confirmed these results. Furthermore, re-analysis of sequenced genomic DNA by tetra-primer PCR analysis (7-11 times) always showed identical results.

CONCLUSIONS

Our set of single-tube assays allows rapid and reproducible genotyping of the majority of CYP2D6 poor metabolizers.

Physiologic effects of anesthesia induced and maintained by intravenous administration of a climazolam-ketamine combination in ponies premedicated with acepromazine and xylazine

OBJECTIVE

To examine the physiologic and pharmacokinetic effects of a technique of total intravenous anesthesia in ponies.

ANIMALS

6 healthy ponies.

PROCEDURE

Ponies were premedicated with acepromazine (0.03 mg/kg of body weight, IV) and xylazine (1.0 mg/kg, IV). Two minutes later, anesthesia was induced with ketamine (2.0 mg/kg, IV) followed by climazolam (0.2 mg/kg, IV). Anesthesia was maintained for 120 minutes by an infusion of climazolam (0.4 mg/kg/h) and ketamine (6.0 mg/kg/h). Oxygen (5 L/min) was supplemented. 20 minutes after the infusion was stopped sarmazenil (0.04 mg/kg, IV) was administered. Cardiovascular and respiratory function measurements were taken before and after premedication, and during anesthesia. Plasma cortsol, ACTH, and catecholamine concentrations were used to assess adrenal and pituitary gland function Ketamine and climazolam kinetics were calculated, on the basis of plasma drug concentrations.

RESULTS

There were no significant changes from pre-xylazine values in heart rate, respiratory rate, arterial blood pressure, cardiac index, systemic vascular resistance, or arterial PO2, PCO2, and pH. Plasma cortisol concentration decreased during anesthesia, but plasma ACTH and catecholamine concentrations did not change. Recovery was fairly smooth, but some excitement and ataxia were noted in 2 ponies.

CONCLUSION

Ketamine-climazolan infusion appeared suitable for maintenance of anesthesia in ponies, although recovery was not ideal in 2 of 6 ponies.

Development of a gas chromatography-mass spectrometry method for determination of ketamine in plasma and its application to human samples

A sensitive and precise gas chromatography-mass spectrometry method with selected ion monitoring has been developed for identification and quantification of the phencyclidine derivative ketamine in human plasma. The assay is based on an alkaline extraction from aqueous to organic solvent from plasma and an efficient gas chromatographic separation on a DB-5 capillary column. The analytical procedure has a coefficient of variation of 0.7-6.2% and from 1.3 to 8.7% within-day and from day-to-day analysis, respectively. The low level of sensitivity was 10 ng/ml. It was used to measure low plasma concentrations in volunteers during ketamine-induced experimental psychosis. The method is not enantio selective.

Plasma triglycerides and three lipoprotein cholesterol fractions are independent predictors of the extent of coronary atherosclerosis

BACKGROUND

The lipoprotein system has manifold links to atherosclerotic disease. LDL cholesterol is related to lesion formation and growth. The cholesterol of HDLs is indicative of protection against atherosclerosis. The status of triglycerides and of subfractions of high-density lipoproteins as risk factors is less certain. Also, the magnitude of the atherogenic/protective power of these factors is not known.

METHODS AND RESULTS

Five hundred patients (418 men and 82 women) were enrolled in an angiographic study. A total of 1006 coronary lesions with > or = 50% narrowing were recorded as study end points. By extent of atherosclerosis, defined as the number of > or = 50% lesions, the study subjects were allocated to one of four ordered categories with 0, 1 to 3, 4 to 6, or 7 to 10 lesions, respectively. Subfractions of HDL cholesterol were determined by a dual precipitation method. By a polychotomous logistic regression model, it was found that, besides age and sex, LDL cholesterol, HDL2 cholesterol, HDL3 cholesterol, and triglycerides were independently predictive (P < .05) of the extent of coronary atherosclerosis. An increase in age by 10 years was associated with an increase of the odds ratio for falling into a higher-extent category by a factor of 1.64, and the same increase of the odds ratio was obtained by increasing LDL cholesterol by 0.92 mmol/L or triglycerides by 1.01 mmol/L and by decreasing HDL2 cholesterol by 0.20 mmol/L or HDL3 cholesterol by 0.46 mmol/L. The less sensitive coronary end point, presence of atherosclerosis (ie, observation of > or = 1 lesion of > or = 50%) depended significantly on age, sex, LDL cholesterol, and HDL2 cholesterol, but not on HDL3 cholesterol or triglycerides.

CONCLUSIONS

In addition to LDL, HDL2, and HDL3 cholesterol, triglycerides also proved independently predictive of the extent of coronary atherosclerosis.

Relation of cyclosporine blood levels to adverse effects on lipoproteins

Hyperlipidemia is common in renal allograft recipients. To elucidate the role of cyclosporine in posttransplant hyperlipidemia, we measured lipids, lipoprotein lipids, and apolipoproteins of thirty-five renal allograft recipients and evaluated their relation to trough cyclosporine blood levels. All patients were on a triple immunosuppressive regimen with equal doses of prednisone and azathioprine, and had stable graft function. Cyclosporine blood levels were significantly correlated to total plasma cholesterol (P = 0.028), low-density lipoprotein cholesterol (P = 0.022), apolipoprotein B (P = 0.017), and the cholesterol/high-density lipoprotein cholesterol ratio (P < 0.002), but not to plasma triglycerides. Significant inverse correlations were found between cyclosporine blood levels and high-density lipoprotein cholesterol (P = 0.034), high-density lipoprotein3 cholesterol (P = 0.025), and apolipoprotein A-1 (P = 0.047), but not high-density lipoprotein2 cholesterol. The independent relation of cyclosporine blood levels to each of the measured lipid parameters was investigated by a stepwise regression model including age, body mass index, interval from transplantation, diabetes mellitus, plasma creatinine, and intake of diuretics and beta-blockers. After correction for these 7 variables, cyclosporine blood levels remained significantly associated with high-density lipoprotein cholesterol, high-density lipoprotein3 cholesterol, apolipoprotein A-1, apolipoprotein B, low-density lipoprotein cholesterol, and the cholesterol/high-density lipoprotein cholesterol ratio. These data suggest that cyclosporine causes atherogenic dyslipidemia.

Relation of the level of high-density lipoprotein subfractions to the presence and extent of coronary artery disease

Plasma lipid profiles, including high-density lipoprotein (HDL) subfractions HDL2 and HDL3, were obtained in 115 men undergoing coronary angiography to assess the relation of lipid levels to coronary artery disease (CAD). CAD was present in 87 patients (76%) and absent in 28 (24%). The largest difference between the 2 groups were observed for HDL2 cholesterol, with a mean of 0.13 mmol/liter (5 mg/dl) in patients with CAD compared with 0.25 mmol/liter (10 mg/dl) in those without CAD (p less than 0.005). Smaller differences were found for HDL3 (1.02 mmol/liter [39 mg/dl] vs 1.19 mmol/liter [46 mg/dl]; p less than 0.005) and HDL (1.15 vs 1.42 mmol/liter [45 vs 55 mg/dl]; p less than 0.001) cholesterol, and apolipoprotein A-1 (1.37 vs 1.50 g/liter; p less than 0.01) and plasma triglycerides (1.79 vs 1.38 mmol/liter [159 vs 122 mg/dl]; p less than 0.05). No significant difference was found for plasma and low-density lipoprotein cholesterol, and apolipoprotein B levels. Simple regression analysis revealed that the most powerful independent variable associated with the extent of CAD was HDL2 cholesterol (Spearman rho = 0.311; p less than 0.001). Stepwise multiple regression analysis proved HDL2 cholesterol and age to be the strongest predictors of extent of CAD. The level of HDL2 cholesterol was reasonably well correlated with HDL cholesterol (r2 = 0.6; p less than 0.0001), but less so with plasma apolipoprotein A-1 (r2 = 0.4; p less than 0.0001). The data add to the growing body of information demonstrating an important association of HDL (and more specifically HDL2) with CAD in men.