Papers by Benjamin K Thomson benthomson.org
Canadian medical education journal, Nov 13, 2018
Background: Competency Based Medical Education (CBME) designates physical examination competency ... more Background: Competency Based Medical Education (CBME) designates physical examination competency as an Entrustable Professional Activity (EPA). Considerable concern persists regarding the increased time burden CBME may place on educators. We developed a novel physical examination curriculum that shifted the burden of physical examination case preparation and performance assessment from faculty to residents. Our first objective was to determine if participation led to sustainable improvements in physical examination skills. The second objective was to determine if resident peer assessment was comparable to faculty assessment. We selected physical exam case topics based on the Objectives of Training in the Specialty of Internal Medicine as prescribed by the Royal College of Physicians and Surgeons of Canada. Internal Medicine residents compiled evidence-based physical exam checklists that faculty reviewed before distribution to all learners. Physical exam practice sessions with whole-group demonstration followed by small-group practice sessions were performed weekly. We evaluated this pilot curriculum with a formative OSCE, during which a resident peer and a faculty member simultaneously observed and assessed examinee performance by . Results: Participation in the novel curriculum practice sessions improved OSCE performance (faculty score mean 78.96 vs. 62.50, p<0.05). Peer assessment overestimated faculty scores (76.2 vs. 65.7, p<0.001), but peer and faculty assessments were highly correlated (R 2 = 0.73 (95% CI 0.50-0.87). This novel physical examination curriculum leads to sustainable improvement of physical examination skills. Peer assessment correlated well with the gold standard faculty assessment. This resident-led physical examination curriculum enhanced physical examination skills in a CBME environment, with minimal time commitment from faculty members.
Background: There remains a paucity of evidence for curricula for the transition to practice (TTP... more Background: There remains a paucity of evidence for curricula for the transition to practice (TTP) stage of Competence by Design internal medicine (IM) training programs. Current entrustable professional activities are based on expert consensus rather than robust subspecialty-specific needs assessment. Methods: A scoping review was completed to identify studies with TTP focus. A national survey was conducted to identify transition experiences for general internal medicine physicians. Results were assessed by grounded theory analysis to identify core topics for TTP curricula. Results: Neither scoping review nor national survey identified TTP topics related to the CanMEDS Medical Expert role. Scoping Review: 41 relevant studies were identified. Most (97.6%) were from North America. The most common study types were observational (survey) or curriculum (13/41 31.7% for each). Only two studies were exclusively in IM, and the most common subspecialty studied was surgical (13/41, 31.7%). T...
Clinical Kidney Journal, 2018
Background. De novo antineutrophil cytoplasmic antibody-associated vasculitis typically arises in... more Background. De novo antineutrophil cytoplasmic antibody-associated vasculitis typically arises in post-reproductive years, but can occur during pregnancy. Concerns of treatment-related teratogenicity persist, while efficacy and safety of new therapies including intravenous immunoglobulin (IVIG) and rituximab are uncertain. There remains a paucity of maternal, fetal and pregnancy outcome data in these women, and therefore a lack of guidance on safe treatment for clinicians. Methods. We conducted a systematic review of the literature and a local, retrospective chart review of women with de novo antibody-associated vasculitis (AAV) in pregnancy. Cochrane, Embase and PubMed databases and relevant conference abstracts were searched. Patient demographics, clinical presentation, management and outcomes (maternal, fetal and pregnancy-related) were analyzed. Results. Twenty-seven cases of de novo AAV in pregnancy were included. Women presented were from 5 to 39 weeks' gestation, of which a majority were in the second trimester (median 20 weeks). The median gravida of women was 2 and the median parity was 1. Women were treated with steroids (89%), cyclophosphamide (CYC) (37%), other immunosuppressive agents [azathioprine (AZA), IVIG, plasma exchange (PLEX)] or no therapy (11%). High rates of serious complications, including preeclampsia (29%) and maternal death (7%), were reported; however, most pregnancies resulted in live birth (73%). Prematurity was common; 73% of live births occurred prior to 37 weeks' gestation and 40% prior to 34 weeks' gestation. The majority of infants were born in the third trimester (median 34.5 weeks). Rates of pregnancy termination were high (23%) and only one intrauterine death was reported, shortly after initiation of therapy (4%). Congenital abnormalities were rare, with one infant having a solitary, pelvic kidney (6%) after maternal treatment with steroids, CYC and PLEX. Use of PLEX, IVIG and AZA increased after 2005, whereas CYC use decreased. Remission often occurred postpartum (60%). Conclusions. De novo AAV in pregnancy can result in uncomplicated pregnancies; however, serious maternal risks exist. Further data on potentially pregnancy compatible therapies such as IVIG and rituximab are needed in this population.
Nephrology Dialysis Transplantation, 2013
What reduction in BMI SDS is required in obese adolescents to improve body composition and cardio... more What reduction in BMI SDS is required in obese adolescents to improve body composition and cardiometabolic health? Arch Dis Child 2010; 95: 256-261 24. Reinehr T, Andler W. Changes in the atherogenic risk factor profile according to degree of weight loss. Arch Dis Child 2004; 89: 419-422
Canadian Journal of Kidney Health and Disease, 2019
Background:Bone mineral density (BMD) decreases postrenal transplantation. Evidence demonstrating... more Background:Bone mineral density (BMD) decreases postrenal transplantation. Evidence demonstrating the effects of bisphosphonates on BMD and fracture risk beyond 1-year posttransplant is sparse in existing literature, but remains essential to enhance clinical outcomes in this population.Objective:Our study aimed to systematically review and meta-analyze the current literature on the use of any bisphosphonate in the adult renal transplant population beyond the first year of renal transplant to determine its effect on BMD and fracture incidence.Design:We conducted a systematic review and meta-analysis of primary research literature that included full-text, English-language, original randomized clinical trials (RCTs) and observational studies.Setting:Patient data were primarily captured in an outpatient setting across various studies.Patients:Our population of interest was patients older than 18 years who received deceased/living donor kidney transplantation and any bisphosphonate with ...
Pre to post-dialysis plasma sodium change better predicts clinical outcomes than dialysate to plasma sodium gradient in quotidian hemodialysis
Hemodialysis International, Apr 3, 2013
Sodium balance across a hemodialysis treatment influences interdialytic weight gain (IDWG), pre-d... more Sodium balance across a hemodialysis treatment influences interdialytic weight gain (IDWG), pre-dialysis blood pressure, and the occurrence of intradialytic hypotension, which associate with patient morbidity and mortality. In thrice weekly conventional hemodialysis patients, the dialysate sodium minus pre-dialysis plasma sodium concentration (δDPNa+) and the post-dialysis minus pre-dialysis plasma sodium (δPNa+) are surrogates of sodium balance, and are associated with both cardiovascular and all-cause mortality. However, whether δDPNa+ or δPNa+ better predicts clinical outcomes in quotidian dialysis is unknown. We performed a retrospective analysis of clinical and demographic data from the Southwestern Ontario Regional Home Hemodialysis program, of all patients since 1985. In frequent nocturnal hemodialysis, δPNa+ was superior to δDPNa+ in predicting IDWG (R(2)=0.223 vs. 0.020, P=0.002 vs. 0.76), intradialytic change in systolic (R(2)=0.100 vs. 0.002, P=0.02 vs. 0.16) and diastolic (R(2)=0.066 vs. 0.019, P=0.02 vs. 0.06) blood pressure, and ultrafiltration rate (R(2)=0.296 vs. 0.036, P=0.001 vs. 0.52). In short hours daily hemodialysis, δDPNa+ was better than δPNa+ in predicting intradialytic change in diastolic blood pressure (R(2)=0.101 vs. 0.003, P=0.02 vs. 0.13). However, δPNa+ was better than δDPNa+ in predicting IDWG (R(2)=0.105 vs. 0.019, P=0.04 vs. 0.68) and pre-dialysis systolic blood pressure (R(2)=0.103 vs. 0.007, P=0.02 vs. 0.82). We also found that the intradialytic blood pressure fall was greater in frequent nocturnal hemodialysis patients than in short hours daily patients, when exposed to a dialysate to plasma sodium gradient. These results provide a basis for design of prospective trials in quotidian dialysis modalities, to determine the effect of sodium balance on cardiovascular outcome.
Hemodialysis International, Jun 18, 2013
Interdialytic weight gain (IDWG) is associated with hypertension, left ventricular hypertrophy, a... more Interdialytic weight gain (IDWG) is associated with hypertension, left ventricular hypertrophy, and all-cause mortality. Dialysate sodium concentration may cause diffusion gradients with plasma sodium and influence subsequent IDWG. Dialysis time and frequency may also influence the outcomes of this Na + gradient; these have been overlooked. Our objective was to identify modifiable factors influencing IDWG. We performed a retrospective multivariable regression analyses of data from 86 home hemodialysis patients treated by hemodialysis modalities differing in frequency and session duration to determine factors involved that predict IDWG. Age, diabetic status, and residual renal function did not correlate with IDWG in the univariable analysis. However, using a combination of backwards selection and Akaike information criterion to build our model, we created an equation that predicted IDWG on the basis of serum albumin, age, patient sex, dialysis frequency, and the diffusive balance of sodium, represented by the product of the duration of dialysis and the patient plasma to dialysate Na + gradient. This equation was internally validated using bootstrapping, and externally validated in a temporally distinct patient population. We have created an equation to predict IDWG on the basis of independent factors readily available before a dialysis session. The modifiable factors include dialysis time and frequency, and dialysate sodium. Patient sex, age, and serum albumin are also correlated with IDWG. Further work is required to establish how improvements in IDWG influence cardiovascular and other clinical outcomes.
BMC Nephrology, Aug 13, 2013
Background: Warfarin prescribing patterns for hemodialysis patients with atrial fibrillation vary... more Background: Warfarin prescribing patterns for hemodialysis patients with atrial fibrillation vary widely amongst nephrologists. This may be due to a paucity of guiding evidence, but also due to concerns of increased risks of warfarin use in this population. The literature lacks clarity on the balance of warfarin therapy between prevention of thrombotic strokes and the increased risks of bleeding in hemodialysis patients with atrial fibrillation. Methods: We performed a survey of Canadian Nephrologists, assessing warfarin prescribing practice, and measured the certainty in making these choices. Results: Respondents were consistently uncertain about warfarin use for atrial fibrillation. This uncertainty increased with a history of falls or starting hemodialysis, even when a high CHADS2 or CHA2DS2VASc score was present. The majority of respondents agreed that clinical equipoise existed about the use of oral anticoagulation in hemodialysis patients with atrial fibrillation (72.2%) and that the results of a randomized controlled trial would be relevant to their practice (98.2%). Conclusions: A randomized controlled trial of warfarin use in hemodialysis patients with atrial fibrillation would clarify the risks and benefits of warfarin use in this population.
Scientific Reports, May 2, 2019
the diagnosis and prognosis of chronic kidney disease (CKD) currently relies on very few circulat... more the diagnosis and prognosis of chronic kidney disease (CKD) currently relies on very few circulating small molecules, which can vary by factors unrelated to kidney function. In end-stage renal disease (esRD), these same small molecules are used to determine dialysis dose and dialytic clearance. therefore, we aimed to identify novel plasma biomarkers to estimate kidney function in CKD and dialytic clearance in esRD. Untargeted metabolomics was performed on plasma samples from patients with a single kidney, non-dialysis CKD, esRD and healthy controls. For esRD patients, pre-and post-dialysis plasma samples were obtained from several dialysis modalities. Metabolomics analysis revealed over 400 significantly different features in non-dialysis CKD and ESRD plasma compared to controls while less than 35 features were significantly altered in patients with a single kidney. N,N,Ntrimethyl-L-alanyl-L-proline betaine (tMAp, AURoC = 0.815) and pyrocatechol sulfate (AUROC = 0.888) outperformed creatinine (AURoC = 0.745) in accurately identifying patients with a single kidney. several metabolites accurately predicted esRD; however, when comparing pre-and post-hemodialysis, tMAp was the most robust biomarker of dialytic clearance for all modalities (AURoC = 0.993). This study describes tMAp as a novel potential biomarker of kidney function and dialytic clearance across several hemodialysis modalities. Chronic kidney disease (CKD) is estimated to affect 11-13% of the global population 1 . CKD primarily manifests as a secondary complication of diabetes and hypertension 2,3 . Progressive renal damage is irreversible and therefore, patients with CKD must manage the disease along with associated comorbidities. Complications from comorbidities are further exacerbated by the accumulation of toxins that follows declining renal function. These complications begin when the estimated glomerular filtration rate (eGFR) declines to <60 ml/min per 1.73 m 2 in stage 3, which represents more than half of all CKD patients 4,5 . In advanced CKD, progression to end-stage renal disease (ESRD) requires renal replacement therapy, which can include various hemodialysis (HD) and peritoneal dialysis (PD) modalities or kidney transplantation to sustain life. Patients with late-stage CKD have a 3 to 6-fold increased risk of mortality, which further increases to 8-fold after initiation of dialysis compared to age-matched subjects with normal or moderately decreased kidney function 6 . Kidney transplantation significantly decreases the risk of mortality and is the only treatment that can effectively reverse toxin accumulation 7 . The accumulation of small molecules that are normally cleared by the kidneys is defined as uremia. The European Uremic Toxin Work Group has identified over 90 uremic metabolites 8 . Several of these uremic toxins are gut-derived and recent studies have associated gut-derived metabolites with cardiovascular events in ESRD. Indeed, indoxyl sulfate, p-cresyl sulfate and phenylacetylglutamine are associated with cardiovascular events that contribute to elevated mortality in ESRD . Indoxyl sulfate and p-cresyl sulfate are highly protein bound
Plasma Sodium Setpoint
Asaio Journal, Sep 1, 2013
Stability of predialysis sodium &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;... more Stability of predialysis sodium &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot;setpoint&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;quot; has not been validated in quotidian dialysis patients. We performed a retrospective review of our home hemodialysis program, to determine the effect of transitioning from conventional thrice weekly to home hemodialysis modalities differing in dialysis duration and frequency (n = 87). Mean sodium setpoint remained constant in patients who went home on intermittent hemodialysis, but decreased by 100 days in frequent nocturnal home hemodialysis (FNHD) (140.5-137.1 mM, p = 0.001) and short hours daily hemodialysis (SHD) (140.2-138.7 mM, p = 0.019) patients with a pretransition setpoint greater than dialysate sodium of 140 mM. Slope of predialysis sodium concentration within the first 100 days post-transition (M100) was less than zero in SHD (95% confidence interval [CI], -0.0081 to -0.0351 mM/day) and FNHD (95% CI, -0.0209 to -0.0695 mM/day) patients who started with a pretransition setpoint greater than dialysate sodium concentration of 140 mM. Change in sodium setpoint (SP) was predicted by dialysis frequency and the difference between dialysate sodium concentration and the pretransition predialysis sodium concentration (R = 35.4%, adjusted R = 33.8%, p &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001). Thus, personalizing dialysate sodium concentrations may be associated with a decrease in SP, which is independently associated with increased mortality. Further research is required to determine whether intentional increases in the SP could improve cardiovascular and all-cause mortality.
Journal of Clinical & Experimental Nephrology, 2017
In thrice weekly conventional haemodialysis patients, higher dialysate sodium concentrations may ... more In thrice weekly conventional haemodialysis patients, higher dialysate sodium concentrations may associate with adverse clinical outcomes. Whether increased frequency and duration of haemodialysis in quotidian and nocturnal patients alters these clinical outcomes is unknown. Methods: A randomized crossover study was performed in conventional, quotidian and nocturnal haemodialysis patients. Dialysate sodium (Dial-Na + ) was personalized 3 mmol/L above (DIALHighSOD) or below (DIALLowSOD) the pre-dialysis plasma sodium set point (SP), with 100 days for each crossover study period. Results: Interdialytic weight gain (IDWG)(2.15 vs. 1.90 L, p=0.002), IDWG as % of target weight (IDWG%)(2.78 vs. 2.39%, p=0.002), pre-dialysis systolic (143.3 vs. 138.3 mm Hg, p=0.001), diastolic (78.6 vs. 75.6 mm Hg, p=0.008) and mean arterial pressure (100.2 vs. 96.5 mm Hg, p=0.003), post-dialysis systolic (135.4 vs. 130.0 mm Hg, p=0.04), diastolic (75.8 vs. 72.4 mm Hg, p=0.006) and mean arterial pressure (95.7 vs. 91.6 mm Hg, p=0.009) were higher in DIALHighSOD than DIALLowSOD. Haemodialysis frequency was associated with decreased (R=-0.295, slope=-0.002, p=0.034) IDWG%, while the opposite was seen with haemodialysis duration (R=0.507, slope=0.002, p<0.001). Haemodialysis duration increased intradialytic change in diastolic blood pressure (R=0.280, slope=1.127, p=0.044), while haemodialysis frequency increased post-dialysis diastolic blood pressure (R=0.366, slope=3.464, p=0.008). Conclusions: These results confirm that dialysate sodium concentration alters clinical outcomes in quotidian and nocturnal haemodialysis patients, and that dialysis frequency and duration correlate in opposing fashions in IDWG. Further studies are required to determine the effect of dialysate sodium on cardiovascular outcomes. This trial is registered at UMIN000026102.
Mycobacterium tuberculosis peritonitis in peritoneal dialysis patients: A scoping review
Nephrology, 2021
BackgroundThe clinical syndrome of Mycobacterium tuberculosis (M. tuberculosis) peritoneal dialys... more BackgroundThe clinical syndrome of Mycobacterium tuberculosis (M. tuberculosis) peritoneal dialysis (PD) peritonitis is poorly understood. Whether local tuberculosis (TB) patterns modify the clinical syndrome, and what factors associate with poor outcomes is also unknown.MethodsA scoping review identified published cases of TB PD peritonitis. Cases from low‐ and high‐TB burden areas were compared, and cases that did or did not suffer a poor clinical outcome were compared.ResultsThere were 216 cases identified. Demographics, presentation, diagnosis, treatment and outcomes were described. Significant delays in diagnosis were common (6.1 weeks) and were longer in patients from low‐TB burden regions (7.3 vs. 3.7 weeks). In low‐TB burden areas, slower diagnostic methods were more commonly used like PD fluid culture (64.3% vs. 32.7%), and treatment was less likely with quinolone antibiotics (6.9% vs. 34.1%). Higher national TB incidence and lower GDP per capita were found in cases that su...
Scientific Reports, 2019
The diagnosis and prognosis of chronic kidney disease (CKD) currently relies on very few circulat... more The diagnosis and prognosis of chronic kidney disease (CKD) currently relies on very few circulating small molecules, which can vary by factors unrelated to kidney function. In end-stage renal disease (ESRD), these same small molecules are used to determine dialysis dose and dialytic clearance. Therefore, we aimed to identify novel plasma biomarkers to estimate kidney function in CKD and dialytic clearance in ESRD. Untargeted metabolomics was performed on plasma samples from patients with a single kidney, non-dialysis CKD, ESRD and healthy controls. For ESRD patients, pre- and post-dialysis plasma samples were obtained from several dialysis modalities. Metabolomics analysis revealed over 400 significantly different features in non-dialysis CKD and ESRD plasma compared to controls while less than 35 features were significantly altered in patients with a single kidney. N,N,N-trimethyl-L-alanyl-L-proline betaine (TMAP, AUROC = 0.815) and pyrocatechol sulfate (AUROC = 0.888) outperforme...
Journal of Nephrology & Therapeutics, 2017
In thrice weekly conventional hemodialysis, dialysate sodium prescription can cause intradialytic... more In thrice weekly conventional hemodialysis, dialysate sodium prescription can cause intradialytic plasma sodium shifts, and undesirable symptoms. However, changes in pre-dialysis plasma sodium setpoint are not observed. Whether these clinical observations are observed in quotidian or nocturnal home hemodialysis has not been prospectively evaluated. A randomized crossover study of conventional, quotidian and nocturnal home hemodialysis patients was performed. Dialysate sodium was personalized 3 mmol/L above (HIGHDIALSOD) or below (LOWDialSOD) the SP, with 100 days for each crossover studies period. Results: Plasma Na + decreased during hemodialysis in LOWDialSOD study period (136.8 to 135.0 mmol/L, p=0.002). Pre-Na + SP (137.4 to 136.8 mmol/L, p=0.03) and Pre-Na + SP slope (0.014 to -0.015 mmol/L/day, p=0.009) decreased from HIGHDialSOD to LOWDialSOD study periods. Conclusions: Personalization of Dial-Na + to below SP leads to reductions in plasma sodium concentration during hemodialysis, in conventional, quotidian and nocturnal home hemodialysis patients. Furthermore, sodium set point changes in response to Dial-Na + prescription. This has the potential to lead to adverse outcomes in a patient population that is followed less frequently and stringently than the in-center hemodialysis population.
Patients with end stage renal disease (ESRD) often require hemodialysis treatments in which blood... more Patients with end stage renal disease (ESRD) often require hemodialysis treatments in which blood's water and dissolved solutes undergo diffusion and convection by exposure to an extracorporeal membrane. The leading cause of death in this population is cardiovascular, and how hemodialysis is prescribed alters total sodium balance, a critical determinant of cardiovascular health. We performed retrospective and prospective analysis of data from patients in the Southwestern Ontario Regional Hemodialysis Program. An increased Dialysate sodium (Dial-Na+) to Pre-dialysis plasma sodium (Pre-Na+) concentration difference (DPNa+) leads to adverse clinical outcomes in hemodialysis patients. The post-to pre-dialysis plasma sodium difference (PPNa+) predicts clinical outcomes equally well as DPNa+ so long as Dial-Na+ is within 3 mmol/L of Pre-Na+. Calculation of DPNa+ requires determination of the Pre-Na+, historically thought to be stable in hemodialysis patients and thus termed "setpoint" (SP). However, we determined that SP is modifiable by hemodialysis prescription. Finally, an equation to predict interdialytic weight gain was created, confirming Dial-Na+, dialysis frequency and duration to be modifiable factors affecting IDWG. Further research is required to validate this equation prospectively, and to determine the impact of changes of SP on cardiovascular morbidity and mortality.
Clinical Kidney Journal, 2014
Background. Outside of pregnancy, anti-glomerular basement membrane (GBM) antibody disease is ass... more Background. Outside of pregnancy, anti-glomerular basement membrane (GBM) antibody disease is associated with significant morbidity and mortality. However, there is limited knowledge regarding de novo anti-GBM disease in pregnancy. Methods. A systematic review was performed to identify maternal, pregnancy and fetal outcomes in de novo anti-GBM disease in pregnancy. Studies were selected from PubMed, EMBASE, Cochrane Library databases and conference proceedings, without language restriction. Results. Data from eight patients were derived from seven case reports and one unpublished case. Most (6/8) patients presented after the first trimester. During pregnancy, acute kidney injury (5/8), anemia (5/8), hematuria (8/8) and proteinuria (8/8) were common. When hemodialysis was required antepartum (5/8), renal function recovery to independence of renal replacement was unlikely (2/5). While pulmonary involvement was common (5/8), no permanent damage was reported (0/8). The majority of cases ended in live births (6/8) although prematurity (6/6), intrauterine growth restriction (2/6), small for gestational age (4/6) and complications of prematurity (1/6) were common. When anti-GBM levels were tested in the living newborn, they were detectable (2/5), but no newborn renal or lung disease was reported (0/6). Complications in pregnancy included gestational diabetes (3/8), hyperemesis gravidarum (2/8) and preeclampsia (2/8). Conclusions. Live births can be achieved in de novo anti-GBM disease in pregnancy, but are commonly associated with adverse maternal, pregnancy and fetal outcomes. Only with awareness of common presentations, and management strategies can outcomes be optimized.
American Journal of Kidney Diseases, 2015
The Choice of Dialysate Sodium is Influenced by Hemodialysis Frequency and Duration: What Should It Be and For What Modality?
Seminars in Dialysis, 2014
Cardiovascular disease is the leading cause of mortality in hemodialysis patients. A chronic stat... more Cardiovascular disease is the leading cause of mortality in hemodialysis patients. A chronic state of volume and pressure overload contributes, and central to this is the net sodium balance over the course of a hemodialysis. Of recent interest is the contribution of the dialysate sodium concentration (Dial‐Na+) to clinical outcomes. Abundant evidence confirms that in thrice‐weekly conventional hemodialysis, higher Dial‐Na+ associates with increased intradialytic weight gain, blood pressure, and cardiovascular morbidity and mortality. On the other hand, low Dial‐Na+ associates with intradialytic hypotension in the same patient population. However, the effect of Dial‐Na+ in short hours daily hemodialysis (SHD; often referred to as “quotidian” dialysis), or nocturnal dialysis (FHND) is less well studied. Increased frequency and duration of exposure to a diffusive sodium gradient modulate the way in which DPNa+ alters interdialytic weight gain, predialysis blood pressure, and intradialy...
What Is Single Needle Cannulation Hemodialysis: Is It Adequate?
Blood Purification, 2014
Background: It is important to know the relative clearances obtained when using single-needle ver... more Background: It is important to know the relative clearances obtained when using single-needle versus double-needle cannulation techniques. Method: Twelve hemodialysis treatments were conducted using a machine that is capable of single-needle as well as double-needle cannulation. Single-needle and double-needle blood flow rates, as well as urea clearance, were compared. Results: The measured blood flow rates were 368 ± 11 ml/min, 294 ± 4 ml/min, 200 ± 0 ml/min, and 100 ± 0 ml/min during double-needle hemodialysis and were 201 ± 10.9 ml/min, 173 ± 44.9 ml/min, 103 ± 4.1 ml/min, and 45 ± 4.9 ml/min during single-needle hemodialysis. The hemodialysis urea clearances at similar blood flow rate (approximately 200 ml/min) were 167 ± 4 ml/min and 161 ± 9 ml/min (paired t test; p > 0.05), respectively. Conclusion: The measured blood flow rates and urea clearances during single-needle hemodialysis were approximately half of the measured blood flow rate during double-needle hemodialysis, an...
Frequent Nocturnal Hemodialysis Associates with Improvement of Prolonged QTc Intervals
Nephron Clinical Practice, 2013
Background/Aims: Sudden cardiac death remains the leading cause of death in hemodialysis (HD) pat... more Background/Aims: Sudden cardiac death remains the leading cause of death in hemodialysis (HD) patients. Prolongation of QTc intervals (as measured by the tangent method) increases sudden cardiac death risk in populations without kidney disease. Methods: We performed a retrospective electrocardiograph (ECG) and chart review of HD patients. Our objectives were (1) to establish the effect of one of four different dialysis modalities on interdialytic QTc intervals, (2) to determine the effect of dialysis frequency and time on QTc interval and on the prevalence of borderline or prolonged QTc intervals, and (3) to determine if changes in QTc interval were simultaneous to changes in electrocardiographic left ventricular mass. Results: Frequent nocturnal HD was associated with a decrease in QTc interval for all patients (from 436.5 to 421.3 ms, p = 0.0187) and for patients who initiated dialysis with prolonged QTc (468.2 to 438.2 ms, p = 0.0134). This change happened before changes in left ...
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Papers by Benjamin K Thomson benthomson.org