Peritoneal dialysis (PD) technique training: what features influence learning time?

BACKGROUND: Within peritoneal dialysis (PD) complications, peritonitis remains a primary challenge for the long-term success of the technique. Proper technique training is essential, since it reduces peritonitis rates, but the adequacy of training has not been standardized. Furthermore, factors influencing training duration have not been well identified. METHODS: We retrospectively analyzed all consecutive training sessions of incident PD patients in our Unit from January 2001 to December 2018. RESULTS: Our analysis included 135 patients, 25.9% were diabetic and median Charlson index (CCI) was 4 (IQR 2-6). Above 13 sessions was chosen as the cut off between usual and prolonged training, as it was our cohort's 75th percentile: 23% (31) had an extended training duration as per our study definition and 77% (104) had a usual training duration. The number of training sessions required increased with age (Spearman Rho 0.404; p = 0.000001), diabetic status (p = 0.001), unemployment status (p = 0.046) and CCI (Spearman Rho 0.369; p = 0.00001). Neither gender, cohabitation status, scheduled PD start, education level nor referral origin, were significant factors impacting training duration. Requiring longer training (> 13 sessions) was a significant risk factor for higher peritonitis risk, but extended training was not related to a shorter technique survival. CONCLUSION: Number of PD training sessions depends on the patient's age and comorbidities, but is not related to social, educational or employment status. Prolonged training duration was a statistically significant predictor of higher peritonitis risk, but it was not related to shorter permanence in PD in our series. Identifying these patients since the training period would be useful to adapt training schedule as an early prevention strategy to minimize the risk of peritonitis and plan a preemptive retraining.

Resuming peritoneal dialysis after catheter removal due to complicated peritonitis.

BACKGROUND: Causes of non-resuming peritoneal dialysis (PD) after complicated peritonitis requiring peritoneal catheter (PC) removal remain poorly studied. METHODS: We reviewed all peritonitis episodes in our center between 1997 and 2017. Patients who restarted PD after PC removal (Group 1) were compared to those who did not (Group 2), identifying the causes. RESULTS: Of 284 peritonitis episodes, PC was removed in 48 patients (16.9%). In 18 (37.5%) patients PC was reinserted, and PD successfully resumed in all, with a median duration of PD afterwards of 14.1 months. In other 30 (62.5%) reinsertion of PC was not attempted. Causes of non-reinsertion were: transfer to hemodialysis 76.6% (n = 23), death 16.7% (n = 5) and transplantation 6.7% (n = 2). Hemodialysis switch was due to non-medical reasons in 47.8% (n = 11) including fear of peritonitis, family decision and social dependence. Group 1 was younger (p = 0.041), with lower Charlson index (p = 0.045) and higher men proportion (p = 0.049). Group 1 had a better patient survival than group 2 (survival at 24 months: 67% and 53%, respectively; log-rank test p: 0.01). There were no differences in survival between groups when adjusted for significant basal characteristics. CONCLUSIONS: Resuming PD after severe peritonitis requiring PC removal is feasible but a high proportion of patients do not restart PD for non-medical reasons, usually older patients with higher Charlson index. A properly structured interview would be a useful tool that could improve return to technique in these patients.

Arteriovenous fistulae after renal biopsy: diagnosis and outcomes using Doppler ultrasound assessment.

BACKGROUND: Percutaneous renal biopsy (PRB) is an important technique providing relevant information to guide diagnosis and treatment in renal disease. As an invasive procedure it has complications. Most studies up to date have analysed complications related to bleeding. We report the largest single-center experience on routine Doppler ultrasound (US) assessment post PRB, showing incidence and natural history of arteriovenous fistulae (AVF) post PRB. METHODS: We retrospectively analysed 327 consecutive adult PRB performed at Ramon Cajal University Hospital between January 2011 and December 2014. All biopsies were done under real-time US guidance by a trained nephrologist. Routine Doppler mapping and kidney US was done within 24 h post biopsy regardless of symptoms. Comorbidities, full blood count, clotting, bleeding time and blood pressure were recorded at the time of biopsy. Post biopsy protocol included vitals and urine void checked visually for haematuria. Logistic regression was used to investigate links between AVF, needle size, correcting for potential confounding variables. RESULTS: 46,5% were kidney transplants and 53,5% were native biopsies. Diagnostic material was obtained in 90,5% (142 grafts and 154 native). Forty-seven AVF's (14.37%) were identified with routine kidney Doppler mapping, 95% asymptomatic (n = 45), 28 in grafts (18.4%) and 17 natives (9.7%) (p-value 0.7). Both groups were comparable in terms of comorbidities, passes, cylinders or biopsy yield (p-value NS). 80% were <1 cm in size and 46.6% closed spontaneously in less than 30 days (range 3-151). Larger AVF's (1-2 cm) took a mean of 52 days to closure (range 13-151). Needle size was not statistically significant factor for AVF (p-value 0.71). CONCLUSIONS: Contrary to historical data published, AVF's are a common complication post PRB that can be easily missed. Routine US Doppler mapping performed by trained staff is a cost-effective, non-invasive tool to diagnose and follow up AVF's, helping to assess management.

URI-CADS: A Fully Automated Computer-Aided Diagnosis System for Ultrasound Renal Imaging.

Ultrasound is a widespread imaging modality, with special application in medical fields such as nephrology. However, automated approaches for ultrasound renal interpretation still pose some challenges: (1) the need for manual supervision by experts at various stages of the system, which prevents its adoption in primary healthcare, and (2) their limited considered taxonomy (e.g., reduced number of pathologies), which makes them unsuitable for training practitioners and providing support to experts. This paper proposes a fully automated computer-aided diagnosis system for ultrasound renal imaging addressing both of these challenges. Our system is based in a multi-task architecture, which is implemented by a three-branched convolutional neural network and is capable of segmenting the kidney and detecting global and local pathologies with no need of human interaction during diagnosis. The integration of different image perspectives at distinct granularities enhanced the proposed diagnosis. We employ a large (1985 images) and demanding ultrasound renal imaging database, publicly released with the system and annotated on the basis of an exhaustive taxonomy of two global and nine local pathologies (including cysts, lithiasis, hydronephrosis, angiomyolipoma), establishing a benchmark for ultrasound renal interpretation. Experiments show that our proposed method outperforms several state-of-the-art methods in both segmentation and diagnosis tasks and leverages the combination of global and local image information to improve the diagnosis. Our results, with a 87.41% of AUC in healthy-pathological diagnosis and 81.90% in multi-pathological diagnosis, support the use of our system as a helpful tool in the healthcare system.

Reversed diastolic intrarenal flow in page kidney following renal biopsy.

Page's kidney is a condition that occurs due to external renal compression, usually caused by a subcapsular haematoma, generating a renal compartmental syndrome with parenchymal damage and renal perfusion alteration. Classically associated with renal trauma, Page's kidney can also arise after invasive renal procedures, such as renal biopsies or percutaneous nephrostomies. Clinically, it can trigger hypertension due to activation of the renin-angiotensin system induced by hypoperfusion secondary to renal parenchymal compression and can also present with varying degrees of renal function impairment. Furthermore, severe acute renal failure may be found particularly in patients with solitary kidneys or renal transplants. We present two cases of Page's kidney after renal biopsy and their PoCUS ultrasound findings. We would like to highlight the reversed diastolic flow on Doppler ultrasound in this entity, a pattern we have found in all two cases.

Routine Kidney Graft Ultrasound After Elective Ureteric Stent Removal: Does it Help?

Transplantation (KTx) is considered to be the best renal replacement therapy, and improving its outcomes remains a primary challenge. KTx ureteral stenting has been used to prevent urological complications, but there is no consensus on the timing of stent removal, and literature regarding routine ultrasonography after ureteric stent removal (RUSUS) to detect complications is lacking. Point-of-care ultrasound has been gaining drive in the medical community in recent years, including nephrologists. We aimed to define the incidence of urological complications diagnosed with RUSUS, if those findings changed patient's management and ultrasound utility. Contrary to previously published data, in our cohort RUSUS allowed a timely diagnosis and early treatment of urological complications, a key factor for successful transplantation. KTx point-of-care ultrasound is a cost-effective and reproducible test that provides relevant information to guide clinical decisions, seeming most efficient when performed approximately 2 weeks post ureteral stent removal. Interventional nephrologists can promptly perform these examinations, reducing waiting times and improving graft and patient's survival.

Renal Transplant Artery Stenosis and Kinking: An Unusual Association.

Renal artery stenosis of the kidney allograft associated with kinking is not a frequent finding. As a correctable cause of graft dysfunction, it is important to diagnose it as soon as possible to avoid further graft damage and improve graft and patient survival. As pulsed wave Doppler ultrasound mapping of the graft's renal arteries is essential to diagnose possible alterations, point of care ultrasound (POCUS) is a highly useful tool for early diagnosis. We present a case in which nephrologists performed this examination promptly allowing a timely diagnosis and treatment plan.

Assisted PD throughout Europe: advantages, inequities, and solution proposals.

BACKGROUND: Peritoneal dialysis provides several benefits for patients and should be offered as first line kidney replacement therapy, particularly for fragile patients. Limitation to self-care drove assisted peritoneal dialysis to evolve from family-based care to institutional programs, with specialized care givers. Some European countries have mastered this, while others are still bound by the availability of a volunteer to become responsible for treatment. METHODS: A group of leading nephrologists from 13 European countries integrated real-life application of such therapy, highlighting barriers, lessons learned and practical solutions. The objective of this work is to share and summarize several different approaches, with their intrinsic difficulties and solutions, which might helpperitoneal dialysis units to develop and offer assisted peritoneal dialysis. RESULTS: Assisted peritoneal dialysis does not mean 4 continuous ambulatory peritoneal dialysis exchanges, 7 days/week, nor does it exclude cycler. Many different prescriptions might work for our patients. Tailoring PD prescription to residual kidney function, thereby maintaining small solute clearance, reduces dialysis burden and is associated with higher technique survival. Assisted peritoneal dialysis does not mean assistance will be needed permanently, it can be a transitional stage towards individual or caregiver autonomy. Private care agencies can be used to provide assistance; other options may involve implementing PD training programs for the staff of nursing homes or convalescence units. Social partners may be interested in participating in smaller initiatives or for limited time periods. CONCLUSION: Assisted peritoneal dialysis is a valid technique, which should be expanded. In countries without structural models of assisted peritoneal dialysis, active involvement by the nephrologist is needed in order for it to become a reality.

Assisted peritoneal dialysis (asPD): age is not the key.

BACKGROUND: Peritoneal dialysis (PD) has multiple advantages over other dialysis modalities. As a home-based therapy, it allows patients to keep their autonomy, avoid frequent hospital visits and carry on with their usual lifestyle. However, as a self-care therapy, dependency has been traditionally considered a contraindication. However, assistance to perform PD (asPD) can be provided regardless of the patient's age and the duration of such help. This paper is aimed at reporting on assisted PD use in a Spanish Center, and is the first report on asPD from this country. METHODS: We retrospectively reviewed the electronic medical records of all patients consecutively treated with PD between May 1997 and December 2020 in our PD Unit. Assisted PD was defined as PD treatment requiring the help of another person. On the basis of the duration of dependency, we divided our cohort into: Group 1: Patients totally dependent at the start of PD treatment; Group 2: self-care patients that developed total dependency during follow up; Group 3: patients who needed short-term PD assistance. Group 4, consisting of 175 self-care PD, served as the control group. RESULTS: Seventy-three percent of patients who required asPD did so during their follow up, showing that an important proportion of patients may require some help even if they were autonomous at the beginning of PD. Even for short time periods, asPD should be an option, as up to 44% of autonomous PD patients became dependent for different reasons over time. Spouses were the most frequent caregivers and absence or loss of caregiver was a main reason for switching to hemodialysis. Fourteen percent of the patients received asPD as palliative care, with clinical symptoms and perceived well-being as the main treatment goals, with adequate results. The need for support and the quality of life were periodically discussed by patients, family members and hospital staff. CONCLUSION: Assisted PD is a safe option for dependent patients, young or elderly, and may result less expensive for our healthcare system, even when caregivers receive a financial incentive.

Spontaneous peritoneal dialysis catheter expulsion: A case series.

There are a significant number of mechanical complications related the peritoneal dialysis (PD) catheter and early diagnosis is key. Between them, the spontaneous extrusion of the catheter is quite uncommon but it should be included among the possible complications of the technique, given that it can be related to frequent situations in PD patients like abdominal wall issues, past immunosuppression or PD fluid leakage. In 25 years our Unit had three cases, probably related to peritoneal fluid leakage, exit site infection and past steroid treatment. Careful examination of abdominal wall preimplantation, adequate break-in period to allow maturation and early detection of exit site infection to start treatment in a timely fashion could help to prevent this rare complication. The complete extrusion of the catheter does not preclude from continuing PD treatment.

Megacalycosis: Sonographic findings of a rare clinical condition.

Recurrent UTI's represent a challenge for physicians and anatomic abnormalities should be investigated thoroughly in this setting. Not all urinary tract dilatations mean obstruction. Several entities can mimic hydronephrosis without actual interruption of urinary flow. Uniform calyceal dilatation without dilatation of pelvis and ureter suggests megacalycosis.

Incoercible Vomiting in a Polycystic (ADPKD) Patient on Peritoneal Dialysis.

Although gastrointestinal symptoms are not uncommon in PD patients due to several causes, such as infusion volume with early satiety, constipation, or peritonitis, sometimes the differential diagnosis is more challenging for nephrologists. We present the case of a woman with end-stage renal disease due to autosomal dominant polycystic kidney disease on PD who presented with swollen legs and incoercible vomiting. After ruling out constipation and infection, an abdominal CT was done, revealing extrinsic compression of the intrahepatic inferior cava vein (ICV) and massive venous thrombosis from ICV to bilateral iliofemoral deep veins. In addition, CT also showed displacement and extrinsic compression of the stomach, pylorus, and duodenum due to an enlarged liver cyst. Percutaneous drainage and sclerosis of the cyst compressing the stomach was performed, anticoagulation was started, and the patient clinically improved with complete resolution of symptoms.

Safety of renal biopsy bleeding prophylaxis with desmopressin.

BACKGROUND: Percutaneous renal biopsy (PRB) is invasive, and bleeding-related complications are a concern. Desmopressin (DDAVP) is a selective type 2 vasopressin receptor-agonist also used for haemostasis. AIM: To evaluate the side effects of intravenous (IV) weight-adjusted desmopressin preceding PRB. METHODS: This was a retrospective study of renal biopsies performed by nephrologists from 2013 to 2017 in patients who received single-dose DDAVP pre-PRB. RESULTS: Of 482 PRBs, 65 (13.5%) received DDAVP (0.3 µg/kg); 55.4% of the PRBs were native kidneys. Desmopressin indications were altered platelet function analyser (PFA)-100 results (75.3% of the patients), urea >24.9 mmol/L (15.5%), antiplatelet drugs (6.1%) and thrombocytopaenia (3%). Of the 65 patients, 30.7% had minor asymptomatic complications, and 3 patients had major complications. Pre-PRB haemoglobin (Hb) <100 g/L was a risk factor for Hb decrease >10 g/L, and altered collagen-epinephrine (Col-Epi) time was a significant risk factor for overall complications. Mean sodium decrease was 0.6 ± 3 mmol/L. Hyponatraemia without neurological symptoms was diagnosed in two patients; no cardiovascular events occurred. CONCLUSION: Hyponatraemia after single-dose DDAVP is rare. A single IV dose of desmopressin adjusted to the patient's weight is safe as pre-PRB bleeding prophylaxis.

Relapsing peritonitis and taurolidine peritoneal catheter lock: One center experience.

BACKGROUND: Relapsing peritonitis due to the development of a biofilm in the catheter's lumen remains an important complication of peritoneal dialysis therapy that endangers technique continuity. Taurolidine catheter lock has proven efficient reducing infection rates in permanent hemodialysis catheters based on its biocidal activity and biofilm detachment effect. Efficacy evidence on its use in peritoneal dialysis catheters is lacking. METHODS: We retrospectively analyzed all relapsing peritonitis episodes from June 2018 until October 2019 in our center. Patients were identified and data were collected from our electronic renal registry and patient's records. RESULTS: Six patients were identified during the study period. Most patients (66.6%) were on automated peritoneal dialysis and the median duration of peritoneal dialysis before the episode of taurolidine was started was 43.66 ± 29.64 months. Mean taurolidine doses were 10 (range: 9-11) and 83.3% (five patients, with peritonitis caused by Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, and Corynebacterium propinquum) had a favorable response and microbial eradication without relapses after taurolidine treatment. Only one patient relapsed by the same organism (Corynebacterium amycolatum) due to non-adherence to the antibiotic treatment prescribed. None of the patients experienced any relevant adverse events, with only two out of six presenting mild transient abdominal discomfort. CONCLUSION: We believe that peritoneal catheter taurolidine lock could be considered in cases of relapsing or refractory peritonitis, as it could prevent catheter removal and permanent switch to hemodialysis in selected cases, although literature is scarce and further studies are needed.

Taurolidine Peritoneal Dialysis Catheter Lock to Treat Relapsing Peritoneal Dialysis Peritonitis.

Peritonitis remains a primary challenge for the long-term success of peritoneal dialysis (PD) technique and one of the main reasons for catheter removal. Prevention and treatment of catheter-related infections are major concerns to avoid peritonitis. The use of taurolidine catheter-locking solution to avoid the development of a biofilm in the catheter's lumen has obtained good results in hemodialysis catheters for reducing infection rates, although there is scarce literature available regarding its utility in PD. We describe the case of a woman in her 60s who developed relapsing peritonitis due to Pseudomonas aeruginosa, with no possibility of removing peritoneal dialysis catheter because she was not a suitable candidate for hemodialysis. After the fourth peritonitis episode caused by Pseudomonas species, the use of taurolidine catheter-locking solution was initiated. She received a total of 9 doses, with a favorable microbiological and clinical outcome and no further relapses more than 10 months after taurolidine PD catheter lock treatment was started. We report the successful elimination of an aggressive bacteria after taurolidine PD catheter lock use, with no relevant adverse events.

Utility of Peritoneal Scintigraphy in Peritoneal Dialysis Patients: One Center Experience.

Background: Peritoneal dialysis (PD) is the RRT of choice in 15% of patients with CKD and has multiple advantages over hemodialysis. PD leaks can prompt technique failure and dropout. Use of peritoneal scintigraphy (PS) for diagnosis of PD leaks has declined in favor of more complex and expensive tests. We analyzed the utility of PS for PD leak diagnosis in our center. Methods: We retrospectively analyzed all PS done in our center from January 2000 until December 2018, inclusive, in all patients on PD with a suspected dialysate leak. Results: A total of 39 PS procedures were done in 36 patients on PD in the study period. Of those, 81% were male and 11% had CKD due to polycystic kidney disease. During this period, 23 leaks were diagnosed, showing an incidence of 6% (three episodes per patient per year). In all cases with negative PS, other tests did not confirm a peritoneal dialysate leak. Conclusions: PS is a safe, inexpensive, reproducible, and highly effective diagnostic tool for peritoneal dialysate leaks that allows nephrologists to tailor or stop PD therapy if required. In our opinion, it should be the first-line imaging test to diagnose PD leaks with minimum exposure to radiation, contrast, or other substances that could irritate the peritoneal membrane. We believe PS should be considered as the initial test of choice to diagnose this PD complication as soon as possible, minimizing technique failure and dropout due to leaks.

Port-a-Cath device: A solution for peritoneal dialysis patients with exhausted access.

With aging population and chronic kidney disease burden increasing worldwide, the need for renal replacement therapy is rising and our patients are getting more complex due to comorbidities and long-standing kidney disease. Deteriorated vascular capital is a frequent feature we have to deal with these days, making even obtaining routine blood tests a hard task. We present two case reports of peritoneal dialysis patients without a peripheral vein access were a Port-a-Cath (Port-a-Cath® Deltec® Smiths Medical) was placed to sort out long-term access. Port-a-Cath manipulation was simple, safe and had no complications neither at implantation nor during its use. We believe that Port-a-Cath placement is an option to be considered when coping with end-stage venous access.

Consensus document for ultrasound training in the specialty of Nephrology. / Documento de consenso para la formación en ecografía en la especialidad de Nefrología.

Ultrasound is an essential tool in the management of the nephrological patient allowing the diagnosis, monitoring and performance of kidney intervention. However, the usefulness of ultrasound in the hands of the nephrologist is not limited exclusively to the ultrasound study of the kidney. By ultrasound, the nephrologist can also optimize the management of arteriovenous fistula for hemodialysis, measure cardiovascular risk (mean intimate thickness), implant central catheters for ultrasound-guided HD, as well as the patient's volemia using basic cardiac ultrasound, ultrasound of the cava inferior vein and lungs. From the Working Group on Interventional Nephrology (GNDI) of the Spanish Society of Nephrology (SEN) we have prepared this consensus document that summarizes the main applications of ultrasound to Nephrology, including the necessary basic technical requirements, the framework normative and the level of training of nephrologists in this area. The objective of this work is to promote the inclusion of ultrasound, both diagnostic and interventional, in the usual clinical practice of the nephrologist and in the Nephrology Services portfolio with the final objective of offering diligent, efficient and comprehensive management to the nephrological patient.

Diagnostic and Interventional Nephrology in Spain: A snapshot of current situation.

BACKGROUND:: Diagnostic and Interventional Nephrology has been a rising field in recent years worldwide. Catheter insertion, renal biopsy, renal ultrasound, and peritoneal dialysis catheter or permanent dialysis catheter insertion are vital to our specialty. At present, many of these procedures are delegated to other specialties, generating long waiting lists and limiting diagnosis and treatment. METHODS:: An online survey was emailed to all Nephrology departments in Spain. One survey response was allowed per center. RESULTS:: Of 195 Nephrology departments, 70 responded (35.8%). Of them, 72.3% (52) had ultrasound equipment, 77.1% insert temporary jugular catheters, and 92.8% femoral. Up to 75.7% (53 centers) perform native renal biopsies, of which 35.8% (19) are real-time ultrasound guided by nephrologists. Transplant kidney biopsies are done in 26 centers, of which 46.1% (12) by nephrologists. Tunneled hemodialysis catheters are inserted in 27 centers (38.5%), peritoneal catheter insertion in 18 (31.6%), and only 2 centers (2.8%) perform arteriovenous fistulae angioplasty. In terms of ultrasound imaging, 20 centers (28.5%) do native renal ultrasound and 16 (22.8%) transplanted kidneys. Of all units 71.4% offer carotid ultrasound to evaluate cardiovascular risk, only in 15 centers (21%) by nephrologists. AVF ultrasound scanning is done in 55.7% (39). CONCLUSION:: Diagnostic and Interventional Nephrology is slowly spreading in Spain. It includes basic techniques to our specialty, allowing nephrologists to be more independent, efficient, and reducing waiting times and costs, overall improving patient care. Nowadays, more nephrologists aim to perform them. Therefore, appropriate training on different techniques should be warranted, implementing an official certification and teaching programs.