Can we improve transthoracic echocardiography training in non-cardiologist residents? Experience of two training programs in the intensive care unit

BACKGROUND

To evaluate the diagnostic performances of two training programs for residents with no prior ultrasound experience to reach competences in extended basic critical care transthoracic echocardiography (CCE) including Doppler capabilities.

METHODS

This is a prospective observational study in two intensive care units of teaching hospitals. Group I (five residents) completed a short training program (4-h theory; 3-h practical); group II (six residents) completed a longer training program (6-h theory; 12-h practical). The residents and an expert examined all patients who required a transthoracic echocardiography. Their agreement studied by Cohen's κ coefficient, concordance coefficient correlation (CCC) and Bland-Altman plots was used as an indicator of program effectiveness.

RESULTS

Group I performed 136 CCEs (mean/resident 27; range 22-32; 65 in ventilated patients) in 115 patients (62 men; 64 ± 18 years; Simplified Acute Physiologic Score [SAPS] II 37 ± 18). Group II performed 158 CCEs (mean/resident 26; range 21-31; 65 in ventilated patients) in 108 patients (64 men; 58 ± 17 years; SAPS II 42 ± 22). Both groups adequately assessed left ventricular (LV) systolic function (κ 0.75, 95 % confidence interval [CI] 0.64-0.86; κ 0.77, 95 % CI 0.66-0.88, respectively) and pericardial effusion (κ 0.83, 95 % CI 0.67-0.99; κ 0.76, 95 % CI 0.60-0.93, respectively). Group II appraised severe right ventricular dilatation and significant left-sided valve disease with good to very good agreement (κ 0.80, 95 % CI 0.56-0.96; κ 0.79, 95 % CI 0.66-0.93, respectively). Regarding left ventricular ejection fraction, E/A ratio, E/e' ratio and aortic peak velocity assessed by group II, CCCs were all >0.70 and the bias (mean difference) ±SD on Bland-Altman analysis was 1.3 ± 8.8 %, 0 ± 0.3, 0.4 ± 2.2 and 0.1 ± 0.4 m/s, respectively. Detection of paradoxical septum (κ 0.65, 95 % CI 0.37-0.93), of heterogeneous LV contraction (κ 0.49, 95 % CI 0.33-0.65) and of respiratory variation of the inferior vena cava (κ 0.27, 95 % CI 0.09-0.45), as well as stroke volume measurement (CCC 0.65, 95 % CI 0.54-0.74; bias ± SD -1.4 ± 4.7 cm), was appraised by group II with moderate agreement requiring probably more comprehensive training.

CONCLUSIONS

Although a training program blending 6-h theory and 12-h practical may be adapted to achieve some essential competences, it seems to be insufficiently to perform a complete extended basic critical care transthoracic echocardiography including Doppler capabilities.

Vitronectin dictates intraglomerular fibrinolysis in immune-mediated glomerulonephritis

During human glomerulonephritis, the severity of injuries correlates with glomerular fibrin deposits, which are tightly regulated by the intraglomerular fibrinolytic system. Here, we evaluated the role of vitronectin (VTN; also known as complement S protein), the principal cofactor of the plasminogen activator inhibitor-1 (PAI-1), in a mouse model of acute glomerulonephritis. We found that in mice subjected to nephrotoxic serum, the absence of VTN resulted in a lower glomerular PAI-1 activity and a higher glomerular fibrinolytic activity. Challenged VTN(-/-) mice displayed significantly less fibrin deposits, proteinuria, and renal failure than their wild-type counterparts. Notably, this protective effect afforded by VTN deficiency was still observed after a C3 depletion. Finally, the injection of VTN(+/+) serum in VTN(-/-) mice induced the glomerular deposition of VTN, increased PAI-1 deposition, decreased glomerular fibrinolytic activity, and aggravated glomerular injury. As in mice, abundant glomerular VTN deposits were also observed in patients with severe glomerulonephritis. Here, we show that plasma-exchange therapy, admittedly beneficial in this clinical context, induces a significant depletion in circulating VTN, which might modulate PAI-1 activity locally and accelerate the clearance of fibrin deposits in the glomeruli. Collectively, these results demonstrate that VTN exerts a deleterious role independently from complement, by directing PAI-dependent fibrinolysis in the glomerular compartment.

Hyperemesis gravidarum: une cause rare d'encéphalopathie de Wernicke

INTRODUCTION

Wernicke encephalopathy - most often observed in alcoholic patients - is due to severe thiamine deficiency.

CASE

We report here the case of a 30-year-old woman who presented with hyperemesis and vomiting during the first trimester of pregnancy (hyperemesis gravidarum). Hyperemesis can lead to severe, symptomatic thiamine deficiency and to severe dehydration with prerenal azotemia.

DISCUSSION

Wernicke encephalopathy is a rare complication of hyperemesis gravidarum. It should be diagnosed as early as possible to prevent long-term complications.

Early Differentiation of Shiga Toxin-Associated Hemolytic Uremic Syndrome in Critically Ill Adults With Thrombotic Microangiopathy Syndromes

OBJECTIVES

Thrombotic microangiopathy syndromes are a heterogeneous group of severe diseases that often require ICU admission. Prompt initiation of targeted therapies is required for atypical hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, whereas there is no specific consensus therapy for Shiga toxin-associated hemolytic uremic syndrome. We sought to compare the characteristics of Shiga toxin-associated hemolytic uremic syndrome, atypical hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura patients at admission in the ICU to allow early differentiation of Shiga toxin-associated hemolytic uremic syndrome from other thrombotic microangiopathy syndromes and help to tailor initial treatment.

DESIGN

Retrospective cohort study.

SETTING

Two ICUs part of the French reference center for thrombotic microangiopathy syndromes.

PATIENTS

Adult patients presenting with features of thrombotic microangiopathy syndromes. Other causes than Shiga toxin-associated hemolytic uremic syndrome, atypical hemolytic uremic syndrome, and thrombotic thrombocytopenic purpura were excluded.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

From September 2003 to January 2017, 236 thrombotic microangiopathy syndrome patients were admitted, including 12 Shiga toxin-associated hemolytic uremic syndrome, 21 atypical hemolytic uremic syndrome, and 91 thrombotic thrombocytopenic purpura. Shiga toxin-associated hemolytic uremic syndrome patients were older than other thrombotic microangiopathy syndromes patients (64 yr [interquartile range, 50-72 yr] vs 42 yr [31-54 yr]; p = 0.007) and presented with more frequent digestive symptoms (92% vs 42%; p < 0.001), especially nonbloody diarrhea and vomiting. Biologically, Shiga toxin-associated hemolytic uremic syndrome patients displayed higher fibrinogen (490 mg/dL [460-540 mg/dL] vs 320 mg/dL [240-410 mg/dL]; p = 0.003) and creatinine levels (2.59 mg/dL [2.12-3.42 mg/dL] vs 1.26 mg/dL [0.61-1.90 mg/dL]; p < 0.001), and less marked anemia (hemoglobin level, 9.7 g/dL [8.7-11.9 g/dL] vs 7.7 g/dL [6.3-9.1 g/dL]; p < 0.001). Forty-two percent (n = 5) required renal replacement therapy, and 83% (n = 10) were treated with plasma exchange before the distinction from other thrombotic microangiopathy syndromes could be made.

CONCLUSIONS

Adult Shiga toxin-associated hemolytic uremic syndrome patients are older, present more frequently with digestive symptoms and display higher hemoglobin and fibrinogen levels than other thrombotic microangiopathy syndromes. However, overlap across the three thrombotic microangiopathy syndromes remains substantial, putting forward the need to implement early plasma therapy until thrombotic thrombocytopenic purpura and atypical hemolytic uremic syndrome can be ruled out.

Exome-First Strategy in Adult Patients With CKD: A Cohort Study

Introduction

Exome sequencing (ES) has widened the field of nephrogenomics in adult nephrology. In addition to reporting the diagnostic yield of ES in an adult cohort study, we investigated the clinical implications of molecular diagnosis and developed a clinical score to predict the probability of obtaining positive result.

Methods

From September 2018 we have used ES to prospectively perform a first-tier liberal exploration of adult nephropathies of unknown origin and/or when a genetic kidney disease was clinically suggested. We also analyzed copy number variant using the same assay.

Results

Molecular diagnosis was made in 127 of 538 patients sequenced (diagnostic yield: 24%), comprising 47 distinct monogenic disorders. Eight of these monogenic disorders (17% [8/47]) accounted for 52% of genetic diagnoses. In 98% (n = 125/127) of the patients, the genetic information was reported to have major clinical implications. We developed a 4-value clinical score to predict the probability of obtaining a molecular diagnosis (area under the receiver operating characteristics curve [AUC] 0.726 [95% confidence interval: 0.670-0.782]) (available at http://allogenomics.com/score).

Conclusion

This study reinforces the role of ES as a first-tier exploration for adult chronic kidney disease patients in whom phenotypes are often poor and atypical. Although external validation is required, our clinical score could be a useful tool for the implementation of nephrogenomics in adults.

[Hemolytic and uremic syndrome and related thrombotic microangiopathies: Epidemiology, pathophysiology and clinics]

Thrombotic microangiopathies (TMA) represent an eclectic group of conditions, which share hemolytic anemia and thrombocytopenia as a common defining basis. Remarkable breakthroughs in the physiopathological setting have allowed for a thorough recomposition of the disparate syndromes, which form the constellation of TMA. In this view, clinicians now discriminate thrombocytopenic thrombotic purpura (TTP) defined by a severe deficiency in ADAMTS13, which is rarely associated with a severe renal involvement and the hemolytic and uremic syndrome (HUS) in which renal impairment is the most prominent clinical feature. HUS can result from toxins stemming from bacterial infections of the digestive tract, alternate complement pathway abnormalities, metabolic or coagulation disorders or, lastly, drug and various toxic compounds. The diverse forms of HUS reflect the insights gained in the understanding of the pathophysiological mechanisms underpinning TMA. In this first part, a broad overview of the epidemiological, physiopathological and clinical aspects of HUS and related TMA syndromes is presented.

Retinal Arteriolar Occlusions and Exudative Retinal Detachments in Malignant Hypertension: More Than Meets the Eye

BACKGROUND

Malignant hypertension is macrovascular and microvascular endothelial injury responsible for multiple organ damage. Considering the anatomical and functional homologies between the posterior pole of the eye and the kidney, ophthalmological explorations may inform clinicians on the mechanisms underpinning concurrent kidney injury in this condition. More specifically, we investigated whether the wall-to-lumen ratio (WLR) of retinal arterioles measured by adaptive optics ophthalmoscopy could be correlated to WLR of kidney arterioles as determined by pathology. We sought to estimate the incidence of retinal arteriole occlusion a supposedly uncommon complication of malignant hypertension.

METHODS

All patients hospitalized in our renal Intensive Care Unit for malignant hypertension between 2016 and 2019 were referred to ophthalmological examinations.

RESULTS

Twenty-seven patients were included. Median retinal WLR was 0.39 [0.31-0.47] and was correlated with initial systolic (r = 0.56, P = 0.003) and mean blood pressure (r = 0.46, P = 0.02) upon admission. The retinal WLR was not correlated to renal pathological findings, as assessed by juxtaglomerular WLR (r = 0.38, P = 0.2), ratio of glomerulosclerosis (r = -0.39, P = 0.2), or tubulointerstitial fibrosis (r = -0.45, P = 0.08). Retinal WLR was not associated with neurological or cardiovascular end-organ damage. Branch retinal artery occlusion was detected in 18.5% of patients and exudative retinal detachment (ERD) in 29.6% of patients, without any significant correlation with canonical signs of retinal hypertension including optic disc swelling.

CONCLUSIONS

In the setting of malignant hypertension, we failed to demonstrate a significant relationship between WLR and other meaningful end-organ injuries. However, branch retinal artery occlusion and ERD may have been hitherto underestimated.

Severe HELLP syndrome masquerading as thrombocytopenic thrombotic purpura: a case report

Background

Thrombotic microangiopathies (TMAs) occurring in the postpartum period may be difficult to manage. They present as the combination of mechanical hemolytic anemia and consumption thrombocytopenia due to endothelial dysfunction. The cause of this endothelial aggression can be multiple: thrombocytopenic thrombotic purpura (TTP), HELLP syndrome, antiphospholipid syndrome, atypical hemolytic and uremic syndrome or acute fatty liver of pregnancy. TTP results from a severe deficiency of ADAMTS13, which is a protease cleaving specifically von Willebrand factor chiefly produced by liver cells. There are two main causes, the production of anti-ADAMTS13 auto-antibodies and, more rarely, a genetic deficiency in ADAMTS13. First-line treatment is based on plasma exchange. HELLP syndrome occurs in the third trimester of pregnancy usually in association with preeclampsia and represents a form of TMA characterized by damage to the sinusoidal capillaries of the liver. Prompt delivery is the main treatment. We present a case illustrating the challenges in discriminating between different postpartum TMAs, with a focus on the distinction between TTP and HELLP syndrome. Specifically, we highlight how acute liver failure (ALF) stemming from HELLP may lead to TTP with a spectacular response to plasma exchanges.

Case

A 28-year-old, 33 + 4 weeks pregnant woman presented with severe preeclampsia complicated by ALF in the setting of partial liver necrosis, disseminated intravascular coagulation, microangiopathic hemolytic anemia and acute kidney injury. Greatly diminished levels of ADAMTS13 (< 5%) activity and neurological impairment suggested an initial diagnosis of thrombotic thrombocytopenic purpura (TTP). Therapeutic plasma exchange (TPE) was initiated and complete renal, neurological, hematological and hepatic recovery was observed. Secondary TTP induced by ALF due to HELLP syndrome was the final diagnosis.

Conclusion

Our case addresses the overlapping nature of postpartum TMAs and raises the possibility that HELLP-induced ALF may constitute an additional mechanism resulting in TTP, thereby opening a possible indication for TPE.

Renal diseases secondary to interferon-β treatment: a multicentre clinico-pathological study and systematic literature review

Background

The spectrum of interferon-β (IFN-β)-associated nephropathy remains poorly described and the potential features of this uncommon association remain to be determined.

Methods

In this study we retrospectively analysed the clinical, laboratory, histological and therapeutic data of patients with biopsy-proven renal disease in a context of IFN-β treatment administered for at least 6 months.

Results

Eighteen patients (13 women, median age 48 years) with biopsy-proven renal disease occurring during IFN-β therapy were included. The median exposure to IFN-β (14 patients were treated with IFN-β1a and 4 patients with IFN-β1b) was 67 months (range 23–165 months). The clinical presentation consists in hypertension (HT; 83%), malignant HT (44%), proteinuria (protU) >1 g/g (94%), reduced renal function (78%), biological hallmark suggesting thrombotic microangiopathy (TMA; 61%), oedematous syndrome (17%) or nephritic syndrome (11%). The pathological findings included typical features of isolated TMAs in 11 cases, isolated focal segmental glomerulosclerosis (FSGS) lesions in 2 cases and 5 cases with concomitant TMA and FSGS lesions. An exploration of the alternative complement pathway performed in 10 cases (63%) did not identify mutations in genes that regulate the complement system. The statistical analysis highlighted that the occurrence of IFN-β-associated TMA was significantly associated with Rebif, with a weekly dose >50 µg and with multiple weekly injections. In all cases, IFN-β therapy was discontinued. Patients with TMA lesions received other therapies, including corticosteroids (44%), eculizumab (13%) and plasma exchanges (25%). At the end of a 36-month median follow-up, persistent HT and persistent protU were observed in 61% and 22% of patients, respectively. Estimated glomerular filtration rate <60 mL/min/1.73 m² was present in 61% of patients.

Conclusions

IFN-β-associated nephropathy must be sought in the case of HT and/or protU onset during treatment. When TMA and/or FSGS are observed on renal biopsy, early discontinuation of IFN-β is essential.

Ockham's razor defeated: about two atypical cases of hemolytic uremic syndrome

Background

Medical investigation is a favorite application of Ockham’s razor, in virtue of which when presented with competing hypotheses, the solution with the fewest assumptions should be privileged. Hemolytic uremic syndrome (HUS) encompasses diseases with distinct pathological mechanisms, such as HUS due to shiga-like toxin-producing bacteria (STEC-HUS) and atypical HUS, linked to defects in the alternate complement pathway. Other etiologies such as Parvovirus B19 infection are exceptional. All these causes are rare to such extent that we usually consider them mutually exclusive. We report here two cases of HUS that could be traced to multiple causes.

Cases presentation

Case 1 presented as vomiting and diarrhea. All biological characteristics of HUS were present. STEC was found in stool (by PCR and culture). After initial remission, a recurrence occurred and patient was started on Eculizumab. Genetic analysis revealed the heterozygous presence of a CFHR1/CFH hybrid gene. The issue was favorable under treatment.

In case 2, HUS presented as fever, vomiting and purpura of the lower limbs. Skin lesions and erythroblastopenia led to suspect Parvovirus B19 primo-infection, which was confirmed by peripheral blood and medullar PCR. Concurrently, stool culture and PCR revealed the presence of STEC. Evolution showed spontaneous recovery.

Conclusions

Both cases defy Ockham’s razor in the sense that multiple causes could be traced to a single outcome; furthermore, they invite us to reflect on the physiopathology of HUS as they question the classical distinction between STEC-HUS and atypical HUS. We propose a two-hit mechanism model leading to HUS. Indeed, in case 1, HUS unfolded as a result of the synergistic interaction between an infectious trigger and a genetic predisposition. In case 2 however, it is the simultaneous occurrence of two infectious triggers that led to HUS. In dissent from Ockham’s razor, an exceptional disease such as HUS may stem from the sequential occurrence or co-occurrence of several rare conditions.

IdeS in anti-glomerular basement membrane disease: Is this the new deal?

IdeS, a proteinase from Streptococcus pyogenes, cleaves IgG antibodies with a unique specificity. Herein, the authors report the dramatic efficacy of IdeS on the levels of anti-glomerular membrane autoantibodies in 3 three patients with Goodpasture disease refractory to standard therapy. The levels of anti-glomerular membrane autoantibodies were reduced to near-zero levels within 2 hours of the injection. However, all patients ultimately required permanent hemodialysis as a result of the late intervention in the course of the disease.

MO367: Non-Invasive Diagnosis of Vancomycin-Induced Acute Kidney Injury Using Urine Microscopy

BACKGROUND AND AIMS

Vancomycin stands out both as being a potent cause of AKI (V-AKI) and as one of the most universally prescribed antimicrobial drugs. From a pathophysiological standpoint, it was hitherto believed that V-AKI stemmed from the intracellular accumulation of vancomycin in the proximal tubule, which elicits oxidative stress and ultimately translates in cell apoptosis. Recently, a study has shown that vancomycin in the setting of overt drug overdose, can co-precipitate with uromodulin causing microspheric obstructive aggregates in the tubular lumen both in experimental models and in patients [1]. Further documentation of this novel mechanism has been hindered by the need to procure kidney tissue so as to perform ad hoc immunostaining. Furthermore, it remains to be proven that the presence of vancomycin microspheres represents a reliable marker for V-AKI. Urine based vancomycin-immunostaining may represent a valuable non-invasive approach.

METHOD

The urine of patients presenting with vancomycin overdose determined by plasma trough levels &gt;15 mg/L along with acute kidney injury (according to KDIGO guidelines) were subjected to light microscopic urinalysis. Whenever microscopic urinalysis yielded the presence of casts, immunostaining was performed. Briefly, a pellet of urine was spread on a slide and immunostaining performed with a specific anti-vancomycin antibody (Abbot 6E-4421, 1/1000) prior to repeat microscopic examination. Infrared spectrophotometry was performed to ascertain the nature of the casts by comparing the spectrum to a reference vancomycin spectrum.

Patients were deemed to have V-AKI whenever at least one vancomycin positive cast was observed following immunostaining.

The urine of control patients was subjected to the same procedure: they were defined as patients exposed to vancomycin with or without vancomycin overdose but with no AKI.

RESULTS

A total of 5 patients with vancomycin overdose KDIGO stage 3 AKI were found to exhibit casts with positive vancomycin immunostaining (Fig. 1). On light microscopic urinalysis, vitreous casts devoid of refringence after polarization could be observed in each case. Upon infrared spectrophotometry, the casts displayed a Fourier transform spectrum consistent with vancomycin.

In three of the cases, V-AKI was considered the sole or primary cause of AKI. The patient displayed abundant and markedly stained casts upon anti-vancomycin immunostaining (Fig. 1A). Overt and massive vancomycin overdosing was evidenced in all cases. In one case, the patient concurrently received piperacillin-tazobactam and in another case the patient was exposed to iodinated contrast media. The renal function course was favourable with full recovery in all three instances.

In two cases, competing causes of AKI were either evidenced or not. In one case, the patient displayed septic shock which indicated vancomycin therapy. In another case, the patient was suspected to have immunoallergic intersititial nephritis. The patients exhibited rare casts with only faint staining (Fig. 1B). In both cases, vancomycin overdose could not be documented. V-AKI was deemed a possible concurrent cause of AKI.

None of the 5 control patients yielded casts after light microscopic urinalysis.

CONCLUSION

Vancomycin cast detection on urine microscopy is feasible and can be enhanced by a straightforward immunostaining technique and represents a unique opportunity for a non-invasive diagnosis of V-AKI. Further studies are required to refine diagnostic criteria-based urine immunostaining detection. They also needed to determine whether detection of V-AKI merely reflects impaired vancomycin urinary excretion in the setting of AKI or can be regarded as a sensitive and specific marker of vancomycin-induced tubular obstruction and injury.

IgA Vasculitis in Patients with Inflammatory Bowel Disease: new insights into the role of TNF-α blockers

OBJECTIVE

Association of IgA vasculitis (IgAV) and inflammatory bowel diseases (IBD) is rarely described, mainly during anti-TNF-α therapy. We aimed to describe the association of IgAV and IBD.

METHODS

We retrospectively analyzed the association of IgAV and IBD through the implication of the GETAID and FVSG networks. Characteristics of IBD and IgAV were collected using a standardized case report form.

RESULTS

Forty-three cases were included. IBD (mainly Crohn's disease (CD) in 58%) preceded IgAV in 38 (88%), with median interval of 9.2 (IQR 5.4-15.4) years. In these 38 patients, at IgAV diagnosis, 5 (13%) had active IBD and 28 (74%) were treated with anti-TNF-α for a median duration of 31.5 (IQR 19-56) months. Main IgAV manifestations were purpura all patients (100%), joints in 20/35 (57%), renal in 15/35 (43%) and gastrointestinal in 11/35 (31%) involvement. IgAV was treated with glucocorticoids in 25 (66%), colchicine in 6 (16%), cyclophosphamide in 6 (16%), and anti-TNF-α were discontinued in 15/28 (54%). No IgAV relapse occurred when TNF-α blockers were stopped, vs 23% in patients pursuing it. Conversely, 5 (33%) had IBD flare or complication after anti-TNF-α cessation vs 1 (8%) in those continuing biologics. Anti-TNF-α were resumed in 6 (40%), with subsequent IgAV relapse in 4 (67%).

CONCLUSIONS

This large cohort suggests that TNF-α blockers may promote the onset of IgAV in IBD. Discontinuation of anti-TNF-α was associated with vasculitis remission but increased risk of IBD relapses, whereas continuation of anti-TNF-α was associated with IBD remission but vasculitis relapse.