Determination of access blood flow from ionic dialysance: theory and validation

BACKGROUND

Several noninvasive techniques have been recently developed for calculating blood flow rate of vascular access in hemodialyzed patients from the on-line measurement of recirculation ratio by injecting a saline bolus when the blood lines are reversed. Here we describe a new noninvasive method based on ionic dialysance measurements without the need of a saline bolus.

METHODS

Mathematical modeling allows to calculate blood flow in vascular access (QA) from the recirculation ratio (Rrev) measured when the blood lines are reversed, without the need to stop ultrafiltration, by using the formula: QA = (QB - QF) 1 - Rrev/Rrev where QB is the blood flow at the dialyzer inlet and QF the ultrafiltration rate. Because the ionic dialysance takes recirculation into account, we tested a new method to assess QA from the measurement of ionic dialysance at normal (D) and reverse (Drev) positions of the blood lines for the same QB. Assuming the absence of access recirculation at normal position of the blood lines, mathematical modeling provides the following relationship: QA = (D - QF)Drev/D - Drev. The estimation of QA from measurement of ionic dialysance (QA-ID) was compared in 28 patients to the estimation of QA by ultrasound dilution technique (QA-US).

RESULTS

The two methods were strongly correlated (QA-ID = 1.24 * QA-US, r2 = 0.86, P < 0.0001). The difference between QA-ID and QA-US was 107 +/- 387 ml/min (mean +/- SD).

CONCLUSIONS

Our method provides a valuable estimation of the vascular access flow and is fully noninvasive, easy to perform (no need of bolus injection and of accurate measurement of QB) and totally inexpensive. Consequently this method is suitable for monitoring access blood flow in hemodialyzed patients in order to predict access thrombosis and to treat significant stenotic lesions before thrombosis.

Smartphone EEG and remote online interpretation for children with epilepsy in the Republic of Guinea: Quality, characteristics, and practice implications

PURPOSE

Children with epilepsy in low-income countries often go undiagnosed and untreated. We examine a portable, low-cost smartphone-based EEG technology in a heterogeneous pediatric epilepsy cohort in the West African Republic of Guinea.

METHODS

Children with epilepsy were recruited at the Ignace Deen Hospital in Conakry, 2017. Participants underwent sequential EEG recordings with an app-based EEG, the Smartphone Brain Scanner-2 (SBS2) and a standard Xltek EEG. Raw EEG data were transmitted via Bluetooth^™ connection to an Android^™ tablet and uploaded for remote EEG specialist review and reporting via a new, secure web-based reading platform, crowdEEG. The results were compared to same-visit Xltek 10-20 EEG recordings for identification of epileptiform and non-epileptiform abnormalities.

RESULTS

97 children meeting the International League Against Epilepsy's definition of epilepsy (49 male; mean age 10.3 years, 29 untreated with an antiepileptic drug; 0 with a prior EEG) were enrolled. Epileptiform discharges were detected on 21 (25.3%) SBS2 and 31 (37.3%) standard EEG recordings. The SBS2 had a sensitivity of 51.6% (95%CI 32.4%, 70.8%) and a specificity of 90.4% (95%CI 81.4%, 94.4%) for all types of epileptiform discharges, with positive and negative predictive values of 76.2% and 75.8% respectively. For generalized discharges, the SBS2 had a sensitivity of 43.5% with a specificity of 96.2%.

CONCLUSIONS

The SBS2 has a moderate sensitivity and high specificity for the detection of epileptiform abnormalities in children with epilepsy in this low-income setting. Use of the SBS2+crowdEEG platform permits specialist input for patients with previously poor access to clinical neurophysiology expertise.

Epilepsy and traditional healers in the Republic of Guinea: A mixed methods study

PURPOSE

The purpose of this study was to characterize the reasons, extent, and impact of traditional medicine use among people with epilepsy (PWE) in the Republic of Guinea.

METHODS

Guinea is a low-income country in sub-Saharan Africa (SSA) with limited healthcare resources. People with epilepsy and their caregivers were seen at a public referral hospital in Conakry, the capital city, where they completed semi-structured interviews with physicians regarding their beliefs about epilepsy, medical care, and engagement with traditional healers.

RESULTS

Of 132 participants (49% children, 44% female, 55% with a university-educated head of household), 79% had seen a traditional healer, and 71% saw a traditional healer before seeing a medical provider for their epilepsy. Participants were treated by a traditional healer for a mean of 39 months before seeing a medical provider. By contrast, 58% of participants reported taking antiepileptic drugs (AEDs) regularly; 46% reported having undergone a head computed tomography (CT) scan; 58% reported having had an electroencephalogram, and 4% reported having had a brain magnetic resonance imaging (MRI) scan.

CONCLUSIONS

Traditional healers in Guinea provide frontline care for PWE in Guinea with considerable delays in AED initiation, even among a cohort of PWE actively seeking medical care. Engaging with these healers is critical for both influencing community perceptions and appropriately managing epilepsy throughout the country.

Epilepsy stigma in the Republic of Guinea and its socioeconomic and clinical associations: A cross-sectional analysis

OBJECTIVE

We aim to quantify the degree of epilepsy stigma perceived by people living with epilepsy (PLWE) in the Republic of Guinea (2019 gross national income per capita, 930 USD) and analyze the demographic, social, and clinical factors associated with epilepsy stigma in this setting.

METHODS

A prospective convenience cohort of PLWE was recruited at the Ignace Deen Hospital in Conakry and evaluated by U.S. and Guinean neurology-trained physicians. A survey instrument exploring demographic, social, and clinical variables was designed and administered. The primary outcome measure was the Stigma Scale of Epilepsy (SSE), a 24-item scale with scores ranging from 0 (least stigma)-100 (most). Regression models were fit to assess associations between SSE score and pre-selected demographic, social, and clinical variables of interest.

RESULTS

249 PLWE (112 female; mean age 20.0 years; 22 % from rural locales; 14 % of participants >16 years old with no formal schooling; 11 % seizure-free for >=6 months) had an average SSE score of 46.1 (standard deviation = 14.5) points. Children had an average SSE score of 45.2, and adults had an average score of 47.0. There were no significant differences between self- and guardian-reported SSE scores (means = 45.8 and 46.5, respectively), p = .86. In univariate analyses, higher stigma scores were associated with more seizures (p = .005), more depressive symptoms (p = .01), and lower household wealth (p = .03). In a multivariable model including sex, educational level, household wealth, generalized tonic-clonic seizures, seizure frequency, and seizure-related burns, only higher seizure frequency (β = -2.34, p = .03) and lower household wealth (β = 4.05, p = .03) were significantly associated with higher SSE scores.

CONCLUSION

In this Guinean cohort of people living with poorly-controlled epilepsy, there was a moderate degree of perceived stigma on average. Stigma was associated with higher seizure frequency and lower household wealth-both potentially modifiable factors.

School status and its associations among children with epilepsy in the Republic of Guinea

BACKGROUND

In low-income countries (LICs), there are multiple barriers for children with epilepsy (CWE) to attend school. We examined potentially modifiable associations with poor school performance in CWE in the West African Republic of Guinea.

METHODS

Children with epilepsy of school age were recruited using public announcements and a clinical register of people with epilepsy at the Ignace Deen Hospital in Conakry in 2018. A team of Guinean and U.S. neurologists and neurologists-in-training interviewed each CWE and parent for his/her epilepsy history, household finances, educational attainment level, and perceived stigma using the Stigma Scale of Epilepsy (SSE). Each child was also tested using the Wechsler Nonverbal Scale of Ability (WNV). Low school performance was defined as either not attending school or being held back a grade level at least once. Potential predictors of low school performance were analyzed.

FINDINGS

Of 128 CWE (mean age: 11.6 years, 48.4% female), 11.7% (n = 15) never attended school, 23.3% (n = 30) dropped out, and 64.8% (n = 83) were currently enrolled. Of CWE attending school, 46.9% (n = 39) were held back a grade level. Overall, 54 children were defined as low performers (LPs) (42%). ;Greater than 100 lifetime seizures (odds ratio (OR) = 8.81; 95% confidence interval (CI) = 2.51, 37.4; p = 0.001) and lower total WNV score (OR = 0.954; 95% CI = 0.926, 0.977; p < 0.001) were significantly associated with poor school performance in separate models, when controlling for potential confounders. Given the strong relationship between seizure freedom and school performance, we estimated that 38 additional CWE (33.6%) could become high performers (HPs) if all CWE were adequately treated to achieve the lifetime seizure category of <10 seizures and could be cognitively intact again. Models examining SSE and household wealth quintile were not significantly associated with school performance.

CONCLUSIONS

Higher lifetime seizures and lower WNV score were significantly associated with low school performance in CWE in Guinea. In spite of our conservative definition of high school performance (attending without failing) and risk of referral bias at an academic center where patients were allowed to self-refer, we demonstrate that seizure control in this setting could increase the number of CWE who could attend and stay in school.

Socioeconomic associations of poorly controlled epilepsy in the Republic of Guinea: cross-sectional study

OBJECTIVE

To explore the socioeconomic factors associated with epilepsy in the Republic of Guinea.

METHODS

People living with epilepsy (PLWE) were prospectively recruited at Ignace Deen Hospital, Conakry, in 2018. An instrument exploring household assets as a measure of wealth was designed and administered. Multivariate logistic regression models with fixed effects were fitted to assess the associations of sociodemographic and microeconomic factors with self-reported frequency of seizures in the prior month and regular intake of antiseizure medications (ASMs). Participants were stratified by age group: children (<13 years), adolescents (13-21) and adults (>21).

RESULTS

A total of 285 participants (mean age 19.5 years; 129 females; 106 children, 72 adolescents, 107 adults, median household size 8) had an average of 4.2 seizures in the prior month. 64% were regularly taking ASMs. Direct costs of epilepsy were similar across income strata, averaging 60 USD/month in the lowest and 75 USD/month in the highest wealth quintiles (P = 0.42). The poorest PLWE were more likely to spend their money on traditional treatments (average 35USD/month) than on medical consultations (average 11 USD/month) (P = 0.01), whereas the wealthiest participants were not. Higher seizure frequency was associated with a lower household education level in adolescents and children (P = 0.028; P = 0.026) and with being male (P = 0.009) in children. Adolescents in higher-educated households were more likely to take ASMs (P = 0.004). Boys were more likely to regularly take ASMs than girls (P = 0.047).

CONCLUSIONS

Targeted programming for children and adolescents in the households with the lowest education and for girls would help improve epilepsy care in Guinea.

[Heart and sports: modifications of electrocardiogram, late potentials and echocardiography. Study of 75 sportsmen and 46 witnesses]

The authors report the results of prospective study, which compared 75 sports subjects and 45 witnesses. All subjects were male, the differentiating parameter being the type of sport practiced. This work analysed surface Electrocardiogramme, thransthoracic echocardiography and high amplification ECG. The statistical study used the student test t compare means and the Chi2 test for the percentages, the signification limit was fixed to 5%. Clinically, our two series didn't show a significant statistical difference, concerning: age, weight, height or arterial pressure. On the electrocardiographical level, the sport's men have a lower cardiac frequency (p = 0.005), a larger PR space (p = 0.05), an important Sokolow parameter (p < 0.005), and repolarisation disorders represented, essentially by negative T waves (p = 0.02) and an upper movement of ST segment in V2-V3 (p < 0.005). Echocardiography showed a dilatation of the right cavities: right auricular (p = 0.0125) and right ventricular (p = 0.025). Move over, it has been showed that the sport's men left ventricular walls were tabor (septal wall, p = 0.0125), (posterior wall, p = 0.025), despite a difference in the values of the left ventricular telediastolic diameter (4 mm average in the two series). The signification limit was not reached and it was also showed that the left auricular was also dilated (p = 0.025). The study of the delayed Potentials, tried to bring an explication to certain sudden deaths of sport's men which are to date unexplained and which could have a rhythmical origin? It is also to be noted that sport's men present more delayed ventricular Potentials. However, the statistical signification was not reached (p = 0.07).

[Silent myocardial infarction and antiphospholipid antibody syndrome]

We describe a case of 18-year-old woman followed for 3 years for systemic lupus erythematosis (SLE) complicated of a nephrectomy. Having like only factor of cardiovascular risk a balanced arterial hypertension. The patient was hospitalized because of choreo-athetosic's movement. We discovered fortuitously during this hospitalization an inferior myocardial necrosis as well as a mitral regurgitation. Coronary angiography was normal and the ventriculography showed an akinesy in the inferior territory. Biology made it possible to pose the diagnosis of antiphospholipid antibody syndrome (APS) on (SLE). We suppose that surgery started myocardial necrosis and underline through this case interest of early identification and appropriate treatment of APS as well as a narrow monitoring particularly in young patients candidates to surgery.

[Correlation between transthoracic and transesophageal echocardiography and surgery in mitral stenosis]

This prospective study was designed to analyse transthoracic and transesophageal echocardiographic findings in the morphological study of the mitral valve and to compare them with surgical findings. This study was based on a series of 60 consecutive patients (38 men and 22 women with a mean age of 36.3 +/- 4.2 years) undergoing open heart surgery for pure or very predominant symptomatic mitral stenosis between November 1993 and December 1994. All patients were investigated by transthoracic and transesophageal echocardiography an average of 3 days before the surgical operation. Qualitative analysis of the mitral valve was rigorously performed according to a 4-point severity score taking into account mobility, thickness and degree of valve calcification as well as the condition of the subvalvular apparatus. The global echocardiographic score corresponded to the sum of the scores for these 4 elements. Transesophageal echocardiographic data and surgical findings were identical: global score: 9.3 vs 9.5, mobility: 2.8 vs 2.9, thickness: 2.6 vs 2.5, calcifications: 1.7 vs 1.8, condition of the subvalvular apparatus: 2.2 vs 2.3. The degree of valve damage was overestimated by transthoracic echocardiography compared to surgical data: global score: 10.4 vs 9.5 (p < 0.05), mobility: 3.1 vs 2.9 (p < 0.05), thickness: 2.8 vs 2.5 (p < 0.01), calcifications: 2.1 vs 1.8 (p < 0.01), but the difference was not significant for the condition of the subvalvular apparatus: 2.4 vs 2.3. In conclusion, surgical findings in pure or very predominant mitral stenosis are more closely correlated with transesophageal echocardiographic data than with transthoracic echocardiography, which tends to overestimate the severity of anatomical lesions, particularly valvular calcification.

[Predictive indices of the persistence of left ventricular dilatation after valve replacement for chronic aortic insufficiency. Echocardiographic study]

The objective of this study was to define the echocardiographic indices predictive of persistence of left ventricular dilatation one year after valve replacement for chronic aortic incompetence. Thirty four consecutive patients (32 men and 2 women, age: 35.6 +/- 10 years) operated for post-rheumatic chronic aortic incompetence, were included in this series. All patients were investigated by echocardiography less than 15 days before and one, six and twelve months after surgery. The parameters studied consisted of measurement of ventricular diameter, shortening fraction and ejection fraction as well as aortic incompetence Doppler indices (jet-left ventriculr outflow tract diameter, jet-left ventricular outflow tract diameter/subaortic diameter ratio, half-pressure time, aortic isthmus end-diastolic velocity). Preoperative echocardiographic data and the results one year after valve replacement were compared for each patient. The left ventricle remained more dilated at one year in patients with a preoperative end-diastolic diameter > 80 mm, an end-systolic diameter > 55 mm, a shortening fraction < 25%, an ejection fraction < 50%, a jet diameter > 16 mm, a jet diameter/subaortic diameter ratio > 65% or a half-pressure time < 350 ms. In conclusion; an end-diastolic diameter > 80 mm, an end-systolic diameter > 55 mm, a shortening fraction < 25%, a jet diameter > 16 mm, a jet diaméter/subaortic diameter ratio > 65% and a half-pressure time < 350 ms appear to represent the main predictive factors of the persistence of ventricular dilatation one year after aortic valve replacement for chronic aortic incompetence.

[Hydatid cyst of the heart. Contribution of two-dimensional echocardiography. Apropos of 2 cases surgically treated]

The authors report the cases of two young Moroccan patients with hydatic cysts of the heart diagnosed by echocardiography. The clinical, radiological and electrocardiographic signs were non-specific. Two-dimensional echocardiography provided a rapid anatomical diagnosis. There were no other visceral localisations of the hydatid disease. In the second case, the hydatid serology was positive and the vascular relations to the tumour were determined preoperatively by coronary angiography. Surgical ablation was performed in both cases. These two cases illustrate the diagnostic value of two-dimensional echocardiography in hydatid cyst of the heart and underline the absolute necessity of surgical ablation before complications develop.

[Muscle bridge and myocardial ischemia. Study of 6 cases]

The authors analyse the clinical and therapeutic aspects of myocardial bridges in a series of 6 male patients between the ages of 41 and 61 years. In every cases, the presenting signs were ischaemic order: one myocardial infarction, three cases of unstable angina and two case of stable angina. On coronary angiography, these muscle bridges involved the left anterior descending artery in all cases. The causal relationships between muscle bridges and myocardial ischaemia are discussed. Among the various factors incriminated, spasm, tachycardia and thrombosis appear to play an important role. Depending on the case, treatment modalities consist of beta-blockers, platelet antiaggregants and calcium channel blockers. Surgical treatment is reserved for patients who remain symptomatic despite medical treatment.

[Early surgery in acute endocarditis complicated by cardiac insufficiency; the Moroccan experience]

The aim of this review of 20 cases was to identify the surgical indications in heart failure complicating the acute phase of left heart valve endocarditis, to determine the optimal timing of surgery and to evaluate the early and medium term postoperative prognosis. Between January 1985 and May 1990, 20 patients (14 men and 6 women with an average age of 29 +/- 7 years) with native left heart valve endocarditis underwent surgery in the acute phase complicated by heart failure. The were 9 aortic regurgitations and 2 mixed mitral and tricuspid regurgitations. The haemodynamic status of the patients was poor before surgery: 15 NYHA class IV and 5 class III. The average time from the onset of heart failure to surgery was 21 days. The surgical procedure was monovalvular replacement in 14 cases, double valve replacement in 4 cases and 2 isolated mitral valvuloplasties. Two patients died in the first postoperative month of irreducible low output syndrome. One patient was reoperated early for dehiscence of a mechanical valve prosthesis. Late complications included 2 cerebrovascular accidents and one reoperation for degeneration of a bioprosthesis. There were no late fatalities. Seventeen of the 18 survivors are regularly followed up with an average of 80 months follow-up: 12 NYHA class I and 5 class II. The most useful prognostic factor was the preoperative haemodynamic status.(ABSTRACT TRUNCATED AT 250 WORDS)

[Effort phlebitis of the upper limb. Presentation of 2 cases and review of the literature]

Effort phlebitis, which represented the principal aetiological form of deep vein thromboses of the upper limb, has become rare, while secondary forms, especially iatrogenic, are more frequent. The authors report two documented cases of effort phlebitis of the upper limb in two manual labourers aged 38 and 40 years. The aetiopathogenic and clinical features and clinical course of this disease are analysed.

[Mobile and obstructive thrombus of the left atrium. Value and risks of transesophageal echocardiography. Report of a case and review of the literature]

Authors report the observation of a young woman of 30 years hospitalised for degeneration of a mitral biologic prosthesis. Transthoracic echocardiography visualizes a voluminous mass of the left auricle of which the character free and destitute of all parietal attachment, doesn't have can be established that by transoesophageal echocardiography that detects another thrombus also free and mobile of the left auricule, unrecognised by transthoracic way. The operative indication is carried in emergency but the patient dies suddenly some hours after this exam. From this observation and a revue of the literature, the contribution and risks possible transoesophageal echocardiography in the exploration of the mobile thrombi of the left auricle, are analysed. Account-held of the potential gravity of homodynamic and embolic complications, the emergency of the surgical indication is underlined.

[Predictive factors of atrial fibrillation in mitral stenosis. Clinical and echocardiographic study]

The objective of this study was to define the predictive factors of atrial fibrillation in pure or very predominant mitral stenosis in a series of 472 consecutive patients divided into 2 groups according to the presence (group I: n = 113) or absence (group II: n = 359) of permanent atrial fibrillation. Univariate analysis showed that predictive factors for atrial fibrillation in mitral stenosis are age (40.3 +/- 9 years vs 31.4 +/- 9.5, p < 0.0001), history of commissurotomy or mitral angioplasty (13 cases vs 10, p < 0.01), functional class III or IV (36 cases vs 43, p < 0.01), history of valvular heart disease (8.4 +/- 7.3 years vs 6.4 +/- 9.2, p < 0.05), left atrial diameter (53.3 +/- 10.3 mm vs 46.5 +/- 8.5, p < 0.0001) and mitral surface area (1.1 +/- 0.4 cm2 vs 1.3 +/- 0.4, p < 0.0001). On multivariate analysis, age and left atrial dilatation were independent predictive factors of atrial fibrillation in mitral stenosis.

[Predictive factors of thromboembolic complications in mitral stenosis in sinus rythm]

The authors analyse the predisposing factors to the development of thromboembolic complications in mitral stenosis in sinus rhythm and propose preventive therapeutic measures. Eighty five consecutive patients with pure or very predominant mitral stenosis in sinus rhythm were included in this study and divided into two groups according to the presence (Group I: n = 27, age: 34.2 +/- 8.31 years) or absence (Group II: n = 58, age: 32.6 +/- 9.7 years) of thromboembolic complications. No significant difference was observed between the two groups for age, sex and functional class. Patients of group I had a more dilated left auricle (57.3 +/- 4.5 vs 48.4 +/- 4.7 mm; p < 0.001) and a smaller mitral surface area (0.8 +/- 0.15 vs 1.1 +/- 0.21 cm2, p < 0.05). The spontaneous left intra-atrial contrast phenomenon was more frequently observed in patients with thromboembolic complications (23 out of 27) than in those not presenting this complication (17 out of 58), (p < 0.001). This phenomenon was the only independent predictive factor on multivariate analysis. In conclusion, left atrial dilatation, the severity of mitral stenosis and especially the presence of spontaneous contrast are the main predictive factors of the development of thromboembolic complications in mitral stenosis in sinus rhythm. Patients presenting one or several of these factors may benefit from prophylactic anticoagulant treatment.