The rationale for the use of low molecular weight heparin for hemodialysis treatments

Does Dietary Intake Differ in Kidney Failure Patients With Sarcopenia and Frailty Treated by Hemodialysis

Background: Inadequate nutrition is common for both sarcopenia and frailty. We investigated whether hemodialysis patients with sarcopenia and frailty have reduced dietary intakes. Methods: Dietary intake, and physical activity were analyzed, along with body composition and relevant clinical data. Results: We studied 51 hemodialysis patients; 52.9% male, age 60 ± 15 years; 33.3% sarcopenic, and 72.5% frail. Dietary protein and calories were similar for sarcopenic and non-sarcopenic patients 0.68 (0.38-3.5) vs. 0.68 (0.18-2.9) g protein/kg/day and 19.2 (8.2-77.5) vs. 15.2 (6.2-38.5) kcal/kg/day. More sarcopenic patients had low physical activity (88.2% vs. 58.8%, X2 4.6, p = .03). Frail and non-frail patients had similar intakes 0.67 (0.28-3.5) versus 0.83 (0.18-1.6) g protein/kg/day and 15.5 (8.1-77.5) vs. 18.8 (6.2-45.4) kcal/kg/day. Sarcopenia was associated with age [Odds ratio (OR) 1.09, 95% confidence interval (CI) [1.02, 1.18], p = .017], body mass index [OR 0.84, 95% CI [0.71, 0.99], p = .042] and lack of exercise [OR 7.62, 95% CI [1.16, 50.29], p = .035]. Frailty was associated with female gender [OR 17.79, 95% CI [2.09, 151.59], p = .008], age [OR 1.13, 95% CI [1.04, 1.22], p = .006], and dialysis vintage [OR 1.55, 95% CI [1.06, 2.26], p = .024]. Conclusion: Hemodialysis patients with sarcopenia and frailty did not have lower dietary protein and calorie intake. Frailty was associated with age and sarcopenia with a sedentary lifestyle.

Characteristics of Frailty in Haemodialysis Patients

Background: Both frailty and cachexia increase mortality in haemodialysis (HD) patients. The clinical frailty score (CFS) is a seven-point scale and less complex than other cachexia and frailty assessments. We wished to determine the characteristics of frail HD patients using the CFS. Methods: Single centre cross-sectional study of HD patients completing physical activity questionnaires with bioimpedance measurements of body composition and hand grip strength (HGS). Results: We studied 172 HD patients. The CFS classified 54 (31.4%) as frail, who were older (70.4±12.2 vs 56.2 ± 16.1 years, p < 0.001), greater modified Charlson co-morbidity (3 (2–3) versus 1.5 (0–3), p < 0.001), and body fat (33 (25.4–40.2) versus 26.2 (15.8–34) %, p < 0.01), but lower total energy expenditure (1720 (1574–1818) versus 1870 (1670–2194) kcal/day, p < 0.01), lean muscle mass index (9.1 (7.7–10.1) versus 9.9 (8.9–10.8) kg/m2), and HGS (15.3 (10.3–21.9) versus 23.6 (16.7–34.4) kg), both p < 0.001. On multivariable logistic analysis, frailty was independently associated with lower active energy expenditure (odds ratio (OR) 0.98, 95% confidence limits (CL) 0.98–0.99, p = 0.001), diabetes (OR 5.09, CL 1.06–16.66) and HGS (OR 0.92, CL 0.86–0.98). Discussion: Frail HD patients reported less active energy expenditure, associated with reduced muscle mass and strength. Frail patients were more likely to have greater co-morbidity, particularly diabetes. Whether physical activity programmes can improve frailty remains to be determined.

Peri-dialytic hypoglycaemia with haemodialysis and on-line post-dilutional haemodiafiltration

INTRODUCTION

We wished to determine whether peri-dialytic hypoglycaemia is a clinical risk in contemporary dialysis patients using glucose containing dialysate.

METHODS

We measured blood glucose pre- and post-haemodialysis or haemodiafiltration, using 5.5 mmol/L glucose dialysate, and body composition by bioimpedance.

RESULTS

239 patients were studied, mean age 65±15.4 years, 59.4% male, 46.4% diabetes, 81.6% treated by haemodiafiltration, Five haemodiafiltration patients (2.1%) had hypoglycaemia, with 82 (33%) a blood glucose <5.5 mmol/L, with fewer diabetics (19.8 vs 74.7%, p=0.001, and %body fat 27.7(20.6-32.6) vs 34.7(26.6-42.8)%, p=0.001. Low post-dialysis blood glucose was negatively associated with glycated haemoglobin (OR 0.94 (0.84-0.97), p=0.004), weight (OR 0.94 (0.89-0.98), p=0.009), and % body fat (OR 0.92 (0.86-0.98), p=0.013).

CONCLUSIONS

Although hypoglycaemia occurred in 2%, 33% had a blood glucose below dialysate glucose. Low post-dialysis glucose was associated with lower glycated haemoglobin and body fat, suggesting nutritional status is important in determining the risk of peri-dialytic hypoglycaemia.

Application of the Clinical Frailty Score and body composition and upper arm strength in haemodialysis patients

Background

To improve outcomes, simple screening tests are required to detect patients at increased risk of mortality. As patients with muscle weakness and wasting are at increased risk of death, we wished to review the use of the Clinical Frailty Score (CFS).

Patients and methods

Dialysis staff graded haemodialysis (HD) patients attending for routine outpatient sessions using the CFS, a functional scoring scale, for patients who require help with their instrumental activities of daily living, classified as clinically frail with scores >4, which were compared with contemporaneous Stoke–Davies comorbidity scores, post-HD body composition measured by bioimpedance, hand grip strength (HGS) and standard laboratory investigations.

Results

The results from 2089 patients (60.2% male) were reviewed, with 890 (42.6%) classified as frail. Frail patients were older [mean ± standard deviation (SD) 71.5 ± 15.6 versus 59.1 ± 15.6 years) and female (50.7% versus 37.3%) and had greater comorbidity {median 2 [interquartile range (IQR) 1–3] versus 1 [0–2]}, body mass index (BMI) (26.0 ± 6.7 versus 25.5 ± 5.4 kg/m²),  C-reactive protein (CRP) [8 (IQR 3–20) versus 5 (2–11) mg/L], lower serum albumin (37.6 ± 4.7 versus 40.1 ± 4.7 g/L),  lean BMI (8.9 ± 1.7 versus 9.7 ± 1.6 kg/m²) and HGS [13.4 (IQR 9.6–18.8) versus 20.9 (14.5–29) kg] (all P < 0.001). Frailty was independently associated in a multivariable logistic model with age {odds ratio [OR] 2.33 [95% confidence limit (CL) 2.01–2.7]}, body fat mass [OR 1.02 (CL 1.01–1.03)], log CRP [OR 1.63 (CL 1.28–2.07)] (all P < 0.001) and comorbidity [OR 1.45 (CL 1.17–1.8); P = 0.001] and negatively associated with albumin [OR 0.95 (CL 0.92–0.98) and HGS [OR 0.91 (CL 0.9–0.93)] (both P < 0.001).

Conclusion

Frail patients are at increased risk of mortality and, as such, simple reliable screening tools are required to rapidly detect patients at risk. The CFS is a useful screening tool that can be readily performed by dialysis staff to identify frail patients. Frailty in HD patients was associated with increasing age, comorbidity, fat weight and inflammation and reduced muscle strength and muscle mass. There is an overlap between frailty and both sarcopenia and protein energy wasting, which requires additional assessments, potentially including body composition, strength, dietary assessments and laboratory investigations. In addition, as the CFS offers a scale, patient trajectories can potentially be serially monitored over time, thus allowing patient-specific interventions or holistic care plans.

Expanded hemodialysis: Is anticoagulation of the dialysis circuit different from online hemodiafiltration and high-flux hemodialysis?

Expanded hemodialysis (HDx) has a high capacity for removing medium and medium-large molecules; however, there are no specific recommendations during HDx for anticoagulation of the dialysis circuit. We aimed to evaluate the differences in the efficacy of anticoagulation procedures using the venous port and 40 mg enoxaparin in HDx compared to high-flux hemodialysis (HF-HD) and postdilution online hemodiafiltration (HDF). We compared anticoagulant activity in 11 patients in HDx, HF-HD, and HDF under similar dialysis conditions. In the 33 dialysis sessions, 40 mg enoxaparin was administered through the venous port, and pre- and postdialysis antifactor Xa activity (aXa) and activated partial thromboplastin time (APTT), postdialysis clotting time of the vascular access, visual clotting score of the dialyzer, and any complications with the extracorporeal circuit or bleeding were registered. APTT postdialysis in HDx was not significantly different from that in HF-HD and HDF. Postdialysis aXa in HDx was not significantly different from that in HF-HD and HDF. We found no significant differences in visual clotting score of the dialyzer. Enoxaparin administered through the venous port was sufficient for anticoagulation within the extracorporeal circuit in HDx, HF-HD, and HDF. There were no differences in postdialysis aXa or APTT, most likely because when low molecular-weight heparin is applied through venous port, lesser enoxaparin concentration reaches the dialyzer. Thus, we conclude that the dose of enoxaparin administered through the venous port should not be adjusted according to dialysis technique.

Anticoagulation in hemodialysis: A narrative review

Systemic anticoagulation in maintenance hemodialysis (HD) has historically been considered necessary to maintain the extracorporeal circuit (ECC) and preserve dialysis efficiency. Unfractionated heparin (UFH) is the most commonly used anticoagulant due to low cost and staff familiarity. Despite widespread use, there is little standardization of heparin dosing protocols in the United States. Although the complication rates with UFH are low for the general population, certain contraindications have led to exploration in alternative anticoagulants in patients with end-stage kidney disease (ESKD). Here we review the current evidence regarding heparin dosing protocols, complications associated with heparin use, and discuss alternatives to UFH including anticoagulant-free routine HD.

Efficacy of enoxaparin in preventing coagulation during high-flux haemodialysis, expanded haemodialysis and haemodiafiltration

Background

Low-molecular-weight heparins (LMWHs) are easily dialysable with high-flow membranes; however, it is not clear whether the LMWH dose should be adjusted according to the membrane type and dialysis technique. This study aimed to evaluate the influence of the dialyser on anticoagulation of the extracorporeal dialysis circuit.

Methods

Thirteen patients received the same dose of LMWH through the arterial port via three dialysis techniques: high-flux haemodialysis (HF-HD), online haemodiafiltration (HDF) and expanded haemodialysis (HDx). All dialysis was performed under similar conditions: duration, 4 h; blood flow, 400 mL/min; and dialysate flow, 500 mL/min. Antifactor Xa (aXa) activity and activated partial thromboplastin time (APTT) were measured before and after the dialysis. Clotting time of the vascular access site after haemodialysis, visual clotting score of the dialyser and any complications with the extracorporeal circuit or bleeding were registered.

Results

Post-dialysis aXa activity in HF-HD (0.26 ± 0.02 U/mL) was significantly different from that in HDF (0.21 ± 0.02 U/mL, P = 0.024), and there was a trend in HDx (0.22 ± 0.01 U/mL, P = 0.05). APTT post-dialysis in HF-HD (30.5 ± 0.7 s) was significantly different from that in HDx (28.2 ± 0.64 s, P = 0.009) and HDF (28.8 ± 0.73 s, P = 0.009).

Conclusions

AXa activity in HDF was significantly lower than that in HF-HD, possibly because of more losses of LMWH through the dialyser. Given the higher anticoagulant loss in HDF and probably in HDx than in HF-HD, the enoxaparin dose administered may be adjusted according to the dialysis technique.

Association Between Low-Molecular-Weight Heparin and Risk of Bleeding Among Hemodialysis Patients: A Retrospective Cohort Study

Background:

Low-molecular-weight heparins (LMWH) replaced unfractionated heparin (UFH) in multiple indications. Although LMWH efficacy in hemodialysis was demonstrated through multiple studies, their safety remains controversial. The potential bioaccumulation in patients undergoing chronic hemodialysis raised the question of bleeding risk among this population.

Objective:

The aim of this study was to evaluate bleeding risk among patients with chronic hemodialysis receiving LMWH or UFH for the extracorporeal circuit anticoagulation.

Design:

We conducted a retrospective cohort study on data extracted from the Régie de l’assurance maladie du Québec (RAMQ) and Med-Echo databases from January 2007 to March 2013.

Setting:

Twenty-one hemodialysis centers in the province of Québec, Canada.

Patients:

Chronic hemodialysis patients.

Measurements:

Bleeding risk evaluated by proportional Cox model for time-dependent exposure using demographics, comorbidities, and drug use as covariates.

Methods:

Minor, major, and total bleeding events identified using International Classification of Diseases, Ninth Revision (ICD-9)/International Classification of Diseases, Tenth Revision (ICD-10) codes in the RAMQ and Med-Echo databases. Exposure status to LMWH or UFH was collected through surveys at the facility level.

Results:

We identified 5322 prevalent and incident patients with chronic hemodialysis. The incidence rate for minor, major, and total bleeding was 9.45 events/1000 patient-year (95% confidence interval [CI]: 7.61-11.03), 24.18 events/1000 patient-year (95% CI: 21.52-27.08), and 32.88 events/1000 patient-year (95% CI: 29.75-36.26), respectively. We found similar risks of minor adjusted hazard ratio (HR: 1.04; 95% CI: 0.68-1.61), major (HR: 0.83; 95% CI: 0.63-1.10), and total bleeding (HR: 0.90; 95% CI: 0.72-1.14) when comparing LMWH with UFH.

Limitations:

Potential misclassification of patients’ exposure status and possible underestimation of minor bleeding risk.

Conclusion:

LMWH was not associated with a higher minor, major, or total bleeding risk. LMWH did not increase the risk of bleeding compared with UFH for the extracorporeal circuit anticoagulation in hemodialysis. The convenience of use and predictable effect made LMWH a suitable alternative to UFH in hemodialysis.

Successful Recovery from Spontaneous Spinal Epidural Hematoma in a Patient Undergoing Hemodialysis

Patient: Male, 70

Final Diagnosis: Spontaneous spinal epidural hematoma

Symptoms: Abdominal pain • chest pain • complete paraplegia

Medication: —

Clinical Procedure: Conservative management

Specialty: Nephrology

Compatibility of Injectable Anticoagulant Agents in Ethanol; In Vitro Antibiofilm Activity and Impact on Polyurethane Catheters of Enoxaparin 400 U/mL in 40% v/v Ethanol

Background and Objectives

Interdialytic lock solutions should maintain catheter patency and prevent catheter infections. We aimed to determine in which conditions injectable anticoagulant agents (IAAs) combined with ethanol are compatible and to assess the antibiofilm activity of the selected combination and its effects on dialysis catheters (DC).

Methods

The solubility and compatibility of unfractionated heparin (UFH), low molecular weight heparins (LMWHs), heparinoids and fondaparinux (50 to 2,500 U/mL) in 30 to 70% ethanol were determined by visual observation. The stability of enoxaparin in ethanol and the ethanol content were assessed by high performance liquid chromatography (HPLC) and titrimetric control, respectively. The bactericidal effect was determined on 24h-old biofilms embedded in silicone-DC. The integrity of polyurethane-DC immersed in anticoagulant-ethanol was assessed by gas chromatography-mass spectrometry (GC-MS) and compared with previously published results.

Results

The compatibility of IAAs and ethanol varied according to IAA type and concentration, and ethanol content. UFH in 40% ethanol was not compatible, whatever the UFH concentration used. Established limits of compatibility of enoxaparin, nadroparin, dalteparin and tinzaparin in 40% ethanol were 1350, 575, 307 and 207 U/ml, respectively, and up to 300 U/ml for danaparoid and 1 mg/mL for fondaparinux. Enoxaparin 400 U/mL in 40% ethanol (Enox/Eth) eradicated biofilm after 4 hours of exposure for Staphylococcus epidermidis, Pseudomonas aeruginosa and Candida albicans and after 24 hours for Klebsiella pneumoniae and S. aureus. Aliphatic carbonate and alcohol compounds were released by polyurethane-DC after Enox/Eth exposure, as after 40% ethanol or saline exposure. There was no significant difference between the amounts released after 30 minutes of exposure to Enox/Eth and 15 days to saline.

Conclusions

A 40% ethanol solution can be combined with all IAAs but UFH. Enox/Eth was effective as an anti-biofilm agent with minor impacts on DC integrity and could be a useful interdialytic lock solution.

Considerations for Systemic Anticoagulation in ESRD

In the setting of end-stage kidney disease, the incidence and risk for thrombotic events are increased and use of anticoagulants is common. The incidence of bleeding, however, is also a frequent issue and creates additional challenges in the management of anticoagulation therapy. Patients with end-stage renal disease are typically excluded from large clinical trials exploring the use of anticoagulants, which limits our knowledge of optimal management approaches. Furthermore, varying degrees of renal failure in addition to conditions that alter the pharmacokinetics of various anticoagulants or pharmacodynamic response may warrant alternative approaches to dosing. This review will explore systemic chronic anticoagulation therapy in the setting of chronic kidney disease where hemodialysis is required. Agents discussed include vitamin K antagonists, low-molecular-weight heparins, fondaparinux, oral factor Xa antagonists, and direct thrombin inhibitors. Clinical challenges, approaches to dosing regimens, and tools for measuring responses and reversal will be explored.

Does the presence of an arteriovenous fistula alter changes in body water following hemodialysis as determined by multifrequency bioelectrical impedance assessment?

Multifrequency bioelectrical impedance assessments (MFBIAs) aid clinical assessment of hydration status for hemodialysis (HD) patients. Many MFBIA devices are restricted to whole body measurements and as many patients dialyze using arteriovenous fistulas (AVFs), we wished to determine whether AVFs affected body water measurements. We reviewed pre- and post-HD segmental MFBIA measurements in 229 patients attending for midweek HD sessions. Up to 144 were dialyzed with a left arm AVF (L-AVF), 42 with a right arm AVF (R-AVF), and 43 by central venous access catheter (CVC). Water content and lean tissue were greater in the left compared to right arm in those patients with L-AVFs both pre and post dialysis (pre 2.1 ± 0.7 vs. 2.0 ± 0.7 L, and post 1.9 ± 0.6 vs. 1.8 ± 0.6 L and pre 2.65 ± 0.9 vs. 2.56 ± 0.8 kg, and post 2.34 ± 0.8 vs. 2.48 ± 0.8 vs. 2.34 ± 0.8 kg, respectively) and were also greater in the right compared to left arm for those patients dialyzing with R-AVFs (pre-HD 1.92 ± 0.5 vs. 1.86 ± 0.6 L and post-HD 1.79 ± 0.5 vs. 1.7 ± 0.5 L, and pre-HD 2.47 ± 0.6 vs. 2.38 ± 0.7 kg and post-HD 2.3 ± 0.74 vs. 1.28 ± 0.7 kg, respectively), all Ps < 0.05. There were no significant differences in arm volumes or composition pre or post dialysis in those dialyzing with CVCs. Segmental MFBIA detects differences in arm water and lean mass in patients with AVFs. The presence on an AVF increases the water content in the ipsilateral arm both pre and post HD. This increased water content of the fistula arm will not be detected by whole body bioimpedance devices.