Occurrence Of Intradialytic Hypotension Research Articles

Intradialytic eating practices and health outcomes among hemodialysis patients, cross-sectional study

Intradialytic eating practices is a subject of debate among hemodialysis patients and is associated with a variety of clinical implications. This study aimed to investigate eating practices during hemodialysis and their influence on health outcome, including various symptoms experienced during dialysis, intradialytic hypotension, dialysis adequacy, and malnutrition. A cross-sectional study was conducted on hemodialysis patients. A structured questionnaire was used to collect information related to sociodemographic, medical history, lifestyle, dialysis, and eating practices. The occurrence of intradialytic hypotension was determined according to the patients' blood pressure measured at the beginning and end of the session, and dialysis adequacy was determined based on the ultrafiltration rate of the patients. Malnutrition was evaluated using renal inpatient screening tool (renal iNUT), and biochemical data was recruited from the patient's hospital records. A total of 260 hemodialysis patients participated in this study. The mean age was 51.29±15.92, and half of the participants were females. The findings showed no significant association between intradialytic eating practices and symptoms developed during dialysis session, intradialytic hypotension, or malnutrition (p>0.05). According to Chi-square test, a statistically significant association was found between eating practices and dialysis adequacy (p=0.037), hemoglobin level (p<0.001), and phosphorous level (p=0.003). Eating practices were not associated with symptoms that developed during dialysis sessions, intradialytic hypotension, or malnutrition, according to our findings. However, findings reveal that it is possible that eating practices may affect the adequacy of dialysis.

Antihypertensive Drug Treatment and the Risk for Intrahemodialysis Hypotension.

Antihypertensive medications are often prescribed to manage hypertension in hemodialysis (HD) patients, and intradialytic hypotension (IDH) is a common complication in these patients. We investigated the risk of IDH in incident HD patients who initiated treatment with antihypertensive drugs in monotherapy. The study was conducted as an emulation of a randomized clinical trial in 4072 incident HD patients who started anti-hypertensive drug treatment between January 2016 to December 2019. The primary outcome was the occurrence of IDH during HD sessions. The Gener alised Estimating Equation (GEE) analysis was adjusted by inverse probability treatment weighting (IPTW). Calcium channel blocker (CCB) use was associated with an IDH incidence rate of 7.4 events per person-year (95% CI: 6.2-8.6). Compared to CCB use, use of beta and alpha-beta blockers was strongly associated with a higher likelihood of IDH (OR [95% CI] 2.27 [1.50-3.43]). Use of angiotensin converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (OR [95% CI] 1.71 [1.14-2.57]) and diuretics (OR [95% CI] 1.52 [1.07-2.16]) were also associated with higher likelihood of IDH compared to CCB use. The study suggests that using beta and alpha-beta blockers, ACE inhibitors or angiotensin II receptor blockers, and diuretics may increase the risk of IDH in HD patients compared to CCB use.

#500 Monitoring relative blood volume and calf bioimpedance in hemodialysis patients

Abstract Background and Aims Measurements of relative blood volume (RBV, %) are used to monitor the relative change in blood plasm during hemodialysis (HD). Continuous measurement of calf extracellular volume (cECV) during HD allows the calculation of relative change in cECV (RCE). RCE was defined as the ratio of cECV to its initial value, cECV0 (RCE = 100 × cECV/cECV0, %). The aim of our study was to investigate the relationship between RBV, RCE and the occurrence of intradialytic hypotension (IDH). Method Fifty-five HD patients were studied. We reduced the HD target weight stepwise by 0.1 to 0.2 kg per HD session until clinically defined IDH symptoms occurred. RBV was monitored using the blood volume monitor (BVM, Fresenius Medical Care, Germany). Whole body bioimpedance spectroscopy (wBIS) provided whole body ECV (wECV) and intracellular volume (wICV) pre and post HD. Continuous calf bioimpedance (Hydra 4200, Xitron Technologies, San Diego, CA USA) provided cECV during HD. Pre HD overhydration (OH) was calculated according to whole body composition model (Chamney et al, Am J Clin Nutr 2007; 85:80). Total number of HD sessions in all patients were divided into three groups according to the pre HD OH: 1) normal OH (NOH, OH &amp;lt; 1 L), 2) moderate OH (MOH, 1 ≤ OH &amp;lt; 4 L) and 3) severe OH (SOH, OH ≥ 4 L). Furthermore, patients were stratified by the presence or absence of IDH in each hydration group. Ultrafiltration rate (UFR), pre HD body weight, body mass index (BMI) were measured. Minimal RBV (RBVMin) and minimal RCE (RCEMin) in each HD session were recorded. These measures represent maximum reduction of fluid in the intravascular and interstitial spaces, respectively. Reducing cECV can be considered as refilling fluid from interstitial transferring to intravascular space driving by ultrafiltration. The difference between RCEMin and RBVMin was defined as vascular refilling capacity. Linear mixed-effect logistic regression (LMELR) analysis was applied to explore relationships between IDH with RBVMin, RCEMin, wECV and BMI. Results We studied 621 HD sessions in 55 patients. MOH was present in 57%, SOH in 22% and NOH in 21% of total number of HD sessions respectively. There were significant differences in age, UFR, RBVMin, RCEMin, pre HD wECV, BMI between three groups, while the IDH rate did not differ significantly (Table 1). RBVMin was inversely correlated with UFR (Fig. 1) in all measurements. Pre HD wECV was the only factor associated with IDH in overall measurement. Pre HD wECV was significantly lower in IDH than in non-IDH patients in the NOH group (Fig. 2). In the MOH group, UFR and RCEMin-RBVMin were higher in IDH than in non-IDH patients (Fig. 3a and Fig. 3b). In the SOH group, Pre HD OH is the major factor associated with IDH (Fig. 4). Conclusion This study found that the major factors leading to IDH are 1) lower hydration status; 2) relative higher UFR; and 3) the limited refilling capacity. RBVMin correlated with UFR, but it did not predict IDH. Combined analysis of RBV and calf bioimpedance may provide a means to quantitate the fluid transport between intravascular and interstitial compartments and could add to an early IDH warning system.

Ambient temperature and the occurrence of intradialytic hypotension in patients receiving hemodialysis.

Intradialytic hypotension (IDH) is a common hemodialysis complication causing adverse outcomes. Despite the well-documented associations of ambient temperatures with fluid removal and pre-dialysis blood pressure (BP), the relationship between ambient temperature and IDH has not been adequately studied. We conducted a cohort study at a tertiary hospital in southern Taiwan between 1 January 2016 and 31 October 2021. The 24-h pre-hemodialysis mean ambient temperature was determined using hourly readings from the weather station closest to each patient's residence. IDH was defined using Fall40 [systolic BP (SBP) drop of ≥40mmHg] or Nadir90/100 (SBP <100 if pre-dialysis SBP was ≥160, or SBP <90mmHg). Multivariate logistic regression with generalizing estimating equations and mediation analysis were utilized. The study examined 110400 hemodialysis sessions from 182 patients, finding an IDH prevalence of 11.8% and 10.4% as per the Fall40 and Nadir90/100 criteria, respectively. It revealed a reverse J-shaped relationship between ambient temperature and IDH, with a turning point around 27°C. For temperatures under 27°C, a 4°C drop significantly increased the odds ratio of IDH to 1.292 [95% confidence interval (CI) 1.228 to 1.358] and 1.207 (95% CI 1.149 to 1.268) under the Fall40 and Nadir90/100 definitions, respectively. Lower ambient temperatures correlated with higher ultrafiltration, accounting for about 23% of the increased IDH risk. Stratified seasonal analysis indicated that this relationship was consistent in spring, autumn and winter. Lower ambient temperature is significantly associated with an increased risk of IDH below the threshold of 27°C, irrespective of the IDH definition. This study provides further insight into environmental risk factors for IDH in patients undergoing hemodialysis.

Prediction of intradialytic hypotension using pre-dialysis features-a deep learning-based artificial intelligence model.

Intradialytic hypotension (IDH) is a serious complication of hemodialysis (HD) that is associated with increased risks of cardiovascular morbidity and mortality. However, its accurate prediction remains a clinical challenge. The aim of this study was to develop a deep learning-based artificial intelligence (AI) model to predict IDH using pre-dialysis features. Data from 2007 patients with 943220 HD sessions at seven university hospitals were used. The performance of the deep learning model was compared with three machine learning models (logistic regression, random forest and XGBoost). IDH occurred in 5.39% of all studied HD sessions. A lower pre-dialysis blood pressure (BP), and a higher ultrafiltration (UF) target rate and interdialytic weight gain in IDH sessions compared with non-IDH sessions, and the occurrence of IDH in previous sessions was more frequent among IDH sessions compared with non-IDH sessions. Matthews correlation coefficient and macro-averaged F1 score were used to evaluate both positive and negative prediction performances. Both values were similar in logistic regression, random forest, XGBoost and deep learning models, developed with data from a single session. When combining data from the previous three sessions, the prediction performance of the deep learning model improved and became superior to that of other models. The common top-ranked features for IDH prediction were mean systolic BP (SBP) during the previous session, UF target rate, pre-dialysis SBP, and IDH experience during the previous session. Our AI model predicts IDH accurately, suggesting it as a reliable tool for HD treatment.

Correlation of NO and ET-1 Levels with Blood Pressure Changes in Hemodialysis Patients after Arteriovenous Fistula Surgery.

Hemodialysis (HD) is the most common renal replacement therapy for patients with end-stage renal disease (ESRD) and can significantly reduce mortality and improve the quality of life of patients. The occurrence of intradialytic hypotension and intradialytic hypertension are important risk factors for death and disability during dialysis in patients with ESRD, yet their etiology remains unclear, and some studies suggest that nitric oxide (NO) and endothelin-1 (ET-1) may play an important role in these hemodynamic alterations. For this purpose we examined the changes in NO and ET-1 levels during hemodialysis in 30 patients on maintenance hemodialysis (MHD) after arteriovenous fistula surgery. Thirty dialysis patients were divided into group I (stable blood pressure during dialysis), group II (Intradialytic hypotension) and group III (Intradialytic hypertension) according to the change of blood pressure (BP) during hemodialysis, with 10 cases in each group. BP of MHD patients were measured Pre-dialysis (Pre-D), at 1 h of dialysis (1h-D), at 2 h of dialysis (Mid-D, 2h-D), at 3 h of dialysis (3h-D), and at the end of dialysis (Post-D); and blood samples were taken from the arterial end at Pre-D, Mid-D, and Post-D to measure NO and ET-1 levels. The results of the analysis showed that as dialysis proceeded and ended, the NO levels in the three groups gradually decreased, with significant differences compared with those before dialysis (p < 0.05); the ET-1 levels in group III gradually increased, with significant differences compared with those before dialysis (p < 0.05), while the increasing trend of ET-1 levels in group I and group II was not significant. The increasing trend of MAP in group I was not significant (p > 0.05); MAP in group II showed a gradual decrease and MAP in group III showed an increasing trend, and the difference between MAP after dialysis and before dialysis was significant (p < 0.05). Correlation analysis showed a significant positive correlation between ET-1 levels and MAP in Group III at Mid-D (r = 0.847, p = 0.002). This shows that serum ET-1 and NO levels are significantly higher than normal in MHD patients after arteriovenous endovascular fistula surgery, and both ET-1 and NO levels are changing during dialysis, and there may be a link between their changes and blood pressure changes. It is suggested that the blood pressure fluctuations that occur during dialysis in MHD patients may be related to endothelial cell dysfunction.

Intra-Dialytique Hypotension: Prevalence and Associated Factors in 2 Haemodialysis Centres in Senegal

Introduction: This study aimed to assess the prevalence of Intra-dialytic hypotension (IDH) according to the European Best Practice Guidelines (EBPG) definition in relation to the number of haemodialysis sessions and the number of chronic haemodialysis patients and to identify its associated factors. Patients and Methods: We conducted an observational, multicentre and looking-forward study of descriptive and analytical purposes over a 4-week period. The study included all patients with regular chronic haemodialysis with at least two sessions per week and a duration of 180 minutes, who consented to participate in the study and were over 15 years of age. Data collection was done with pre-established forms. The following data were collected: blood pressure before each session, at 30, 60, 120, 180 and 240 minutes of each session; socio-demographic data; dialysis data; clinical, paraclinical, therapeutic data and nursing interventions. Results: The mean age of the patients was 43.84 ± 12.10 years. Among 568 haemodialysis sessions recorded in 50 patients, IDH was noted in 12 haemodialysis sessions, representing a prevalence of 2.11%. Fatigue was found in 5 sessions with IDH episodes (41.66%) followed by yawning (25%), nausea ± vomiting (16.66%) and cramps (16.66%). As nursing interventions, Trendelenburg position and normal saline administration were performed in all IDH episodes. High blood pressure, inter-dialytic weight gain greater than 3 kg, Uf/H > 10 ml/kg/H, anaemia and hypoalbuminaemia were associated with the occurrence of IDH. Conclusion: The prevalence of IDH according to the EBPG definition is low. However, it is an important cause of morbidity and mortality, especially cardiovascular involvement, and the factors associated with its presence have been clearly identified.

Correlation between body composition measurement by bioelectrical impedance analysis and intradialytic hypotension.

To explore the correlation between body composition measurement by bioelectrical impedance analysis (BIA) and intradialytic hypotension (IDH). The clinical data of 127 patients with end-stage renal disease (ESRD) who underwent regular dialysis in the Blood Purification Center of the Second Affiliated Hospital of Chongqing Medical University were retrospectively analyzed. According to the occurrence of IDH, the patients were divided into IDH group and intradialytic normotension group. The difference in body composition measured by BIA and its relationship with IDH were compared between the two groups. Compared with intradialytic normotension group, the intracellular water (ICW) ratio (P = 0.009), extracellular water (ECW) ratio (P = 0.029), total body water (TBW) ratio (P = 0.012), protein ratio (P = 0.010), soft lean mass (SLM) ratio (P = 0.011), fat-free mass (FFM) ratio (P = 0.012) and skeletal muscle mass (SMM) ratio (P = 0.009) in IDH group were significantly decreased. However, the fat mass (FM) ratio (P = 0.016), percentage body fat (PBF) ratio (P = 0.001), extracellular water/total body water (ECW/TBW) ratio (P = 0.036), extracellular water/total body water in trunk (ECW/TBWT) ratio (P = 0.045) and visceral fat area (VFA) (P = 0.003) in IDH group were significantly increased when compared with intradialytic normotension group. In addition, there was a positive correlation between systolic blood pressure (SBP) during IDH and ECW ratio, ECW/TBW ratio, and ECW/TBWTR ratio before dialysis. The body composition of dialysis patients is closely related to the occurrence of IDH. Strengthening the body composition management of dialysis patients outside the hospital may reduce the occurrence of IDH and improve the long-term prognosis of dialysis patients.

Association between quality of life and various aspects of intradialytic hypotension including patient-reported intradialytic symptom score

BackgroundThere is increasing awareness that, besides patient survival, Quality of Life (QOL) is a relevant outcome factor for patients who have a chronic disease. In haemodialysis (HD) patients, intradialytic hypotension (IDH) is considered one of the most frequent complications, and this is often accompanied by symptoms. Several studies have investigated QOL in dialysis patients, however, research on the association between intradialytic symptoms and QOL is minimal. The goal of this study was to determine whether the occurrence of IDH has an influence on the perception of QOL.MethodsDuring 3 months, haemodynamic data, clinical events, and interventions of 2623 HD-sessions from 82 patients were prospectively collected. The patients filled out a patient-reported intradialytic symptom score (PRISS) after each HD session. IDH was defined according to the EBPG as a decrease in SBP ≥20 mmHg or in MAP ≥10 mmHg associated with a clinical event and need for nursing interventions. Patient’s self-assessment of QOL was evaluated by the 36-Item Short-Form Health Survey.ResultsThere were no significant associations between the mental summary score or the physical summary score and the proportion of dialysis sessions that fulfilled the full EBPG definition. A lower PRISS was significantly associated with the proportion of dialysis sessions that fulfilled the full EBPG definition (R = − 0.35, P = 0.0011), the proportion of dialysis sessions with a clinical event (R = − 0.64, P = 0.001), and the proportion of dialysis sessions with nursing interventions (R = − 0.41, P = 0.0001). The physical component summary and mental component summary were significantly negatively associated with the variable diabetes and positively with PRISS (P = 0.003 and P = 0.005, respectively). UF volume was significantly negatively associated with mental health (P = 0.02) and general health (P = 0.01).ConclusionsOur findings suggest that the EBPG definition of IDH does not capture aspects of intradialytic symptomatology that are relevant for the patient’s QOL. In contrast, we found a significant association between QOL and a simple patient-reported intra-dialytic symptom score, implying that how patients experience HD treatment influences their QOL.

Hypertonic Mannitol for the Prevention of Intradialytic Hypotension: A Randomized Controlled Trial

Intradialytic hypotension (IDH) is a common complication at the initiation of hemodialysis (HD) therapy, is associated with greater mortality, and may be related to relatively rapid shifts in plasma osmolality. This study sought to evaluate the effect of an intervention to minimize intradialytic changes in plasma osmolality on the occurrence of IDH. Double-blind, single-center, randomized, controlled trial. Individuals requiring initiation of HD for acute or chronic kidney disease. Mannitol, 0.25g/kg/h, versus a similar volume of 0.9% saline solution during the first 3 HD sessions. The primary end point was average decline in systolic blood pressure (SBP). The secondary end point was the proportion of total sessions complicated by IDH (defined as a decrease≥ 20mm Hg from the pre-HD SBP). Exploratory end points included biomarkers of cardiac and kidney injury. 52 patients were randomly assigned and contributed to 156 study visits. There were no significant differences in average SBP decline between the mannitol and placebo groups (15±11 vs 19±16mm Hg; P= 0.3). The proportion of total sessions complicated by IDH was lower in the mannitol group compared to placebo (25% vs 43%), with a nominally lower risk for developing an episode of IDH (OR, 0.38; 95% CI, 0.14-1.00), though this finding was of borderline statistical significance (P= 0.05). There were no consistent differences in cardiac and kidney injury biomarker levels between treatment groups. Modest sample size and number of events. In this pilot randomized controlled trial studying patients requiring initiation of HD, we found no difference in absolute SBP decline between those who received mannitol and those who received saline solution. However, there were fewer overall IDH events and a nominally lower risk for dialysis sessions being complicated by IDH in the mannitol group. A larger multicenter randomized controlled trial is warranted. Government funding to an author (Dr Mc Causland is supported by National Institute of Diabetes and Digestive and Kidney Diseases grant K23DK102511). Registered at ClinicalTrials.gov with study number NCT01520207.

Vasopressin and prevention of hypotension during hemodialysis.

Context:The occurrence of intradialytic hypotension (IDH) during hemodialysis (HD) continues to be a main problem in patients with ESRD (end-stage kidney disease). It also negatively affects health-related quality of life. We aimed to determine vasopressin effect in decreasing IDH.Evidence Acquisition:We reviewed clinical and experimental literature in a variety of sources, including PubMed, Current Content, Scopus, Embase, and Iranmedex regarding the possible effect of vasopressin administration in prevention of hypotension during HD to clarify its mechanism, efficacy, and safety.Results:Although arginine vasopressin is widely recognized for its anti-diuretic properties, it is also a well-recognized vasoconstrictor. It has been shown that the vasopressin release (as it would normally be expected) does not increase in the majority of HD patients with recurrent dialysis hypotension. In addition, it has also been reported that vasopressin secretion (due to the osmotic stimulation) is the most important mechanism in blood pressure control in ESRD patients receiving hypertonic solution for IDH. Therefore, it is suggested that vasopressin administration may improve hemodynamic stability among ESRD patients during HD. There are few clinical trials about this issue, suggesting that administration of exogenous vasopressin may be significantly associated with a decreased incidence of IDH as well as cardiovascular stability in ESRD patients in need of volume removal during HD.Conclusions:Vasopressin insufficiency may have an important role in the pathogenesis of hemodynamic instability during HD and administration of exogenous vasopressin is significantly associated with a lower incidence of IDH.

The dialysis staff workload and the blood volume tracking system during the hemodialysis sessions of hypotension-prone patients.

Intradialytic hypotension (IDH) represents a common hemodialysis (HD) complication. Blood volume tracking (BVT) is a tool regulating the relative blood volume changes and potentially reducing the occurrence of IDH. The aim of this study was to evaluate the ability of BVT to reduce the staff workload associated to IDH. Ten hypotension-prone HD patients were treated each with 39 conventional HD (HD) sessions and then switched to 39 HD sessions with BVT (HD-BVT). The staff interventions related to IDH were monitored by a trained staff. Dialysis sessions complicated by IDH and staff interventions were affected by BVT (HD: 102 and 127 vs. HD-BVT: 57 and 59, respectively, for both p<0.001). The time consumed by staff in IDH management was decreased by HD-BVT (1416 vs. 578 min, p<0.001). The effectiveness of BVT to reduce the frequency of IDH leads to a reduction of the dialysis staff workload with fewer staff interventions, allowing for major work-time saving.

Pre to post‐dialysis plasma sodium change better predicts clinical outcomes than dialysate to plasma sodium gradient in quotidian hemodialysis

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.

Absolute Blood Volume in Hemodialysis Patients: Why Is It Relevant, and How to Measure It

Intradialytic hypotension (IDH) is the most common complication during hemodialysis and is associated with significant morbidity. It occurs as a consequence of a reduction in blood volume during ultrafiltration. Today, devices for monitoring relative blood volume (i.e. the intradialytic blood volume as a fraction of the blood volume at the start of the dialysis treatment) are routinely available and have been used to analyze the relationship between changes in relative blood volume and the occurrence of IDH in an attempt to derive critical thresholds that, when observed, would help avoid hypotensive episodes during the treatment. However, the results have been unsatisfactory in many patients. Here we illustrate the importance of absolute blood volume in hemodialysis patients, summarize the acute physiologic mechanisms involved in the preservation of adequate circulation during ultrafiltration, and outline why hemodialysis patients are often particularly vulnerable to reductions in blood volume. We then discuss the shortcomings of relative blood volume measurements, make a case for the superiority of absolute blood volume measurements, and introduce the reader to a mathematical concept that allows relative blood volume devices to be used for the estimation of absolute blood volume. Finally, we discuss the implications of absolute blood volume beyond IDH and propose a paradigm shift in the approach to dry weight attainment.

Association of intradialytic hypotension and convective volume in hemodiafiltration: results from a retrospective cohort study

BackgroundHemodiafiltration (HDF), as a convective blood purification technique, has been associated with favorable outcomes improved phosphate control, removal of middle-molecules such as Beta2-microglobulin and the occurrence of intradialytic hypotension (IDH) as compared to diffusive techniques. The aim of this retrospective cohort study in dialysis patients receiving HDF in one urban dialysis facility in Mexico City was to investigate the occurrence of IDH during HDF treatments with varying convective volume prescriptions.MethodsSubjects were stratified into equal groups of percentiles of convective volume prescription: Group 1 of 0 to 7.53 liters, group 2 of 7.54 to 14.8 liters, group 3 of 14.9 to 16.96 liters, group 4 of 16.97 to 18.9 liters, group 5 of 21 to 19.9 liters and group 6 of 21.1 to 30 liters. Logistic Regression with and without adjustment for confounding factors was used to evaluate factors associated with the occurrence of IDH.Results2276 treatments of 154 patients were analyzed. IDH occurred during 239 HDF treatments (10.5% of all treatments). Group 1 showed 31 treatments (8.2%) with IDH whereas group 6 showed IDH in only 15 sessions (4% of all treatments). Odds Ratio of IDH for Group 6 was 0.47 (95% CI 0.25 to 0.88) as compared to Group 1 after adjustment.ConclusionsIn summary the data of this retrospective cohort study shows an inverse correlation between the occurrence of IDH and convective volume prescription. Further research in prospective settings is needed to confirm these findings.

Mathematical Modeling of Thermal and Circulatory Effects During Hemodialysis

Intradialytic hypotension (IDH) is one of the most common complications of hemodialysis (HD) treatment. The initiating factor of IDH is a decrease in blood volume, which is related to an imbalance between ultrafiltration (UF) and refilling rate. Impaired reactivity of resistance and capacitance vessels in reaction to hypovolemia plays possibly a major role in the occurrence of IDH. These vessels also fulfill an important function in body temperature regulation. UF-induced cutaneous vasoconstriction would result in a reduced surface heat loss and an increase in core temperature. To release body heat, skin blood flow is increased at a later stage of the HD treatment, whereby possibly IDH can occur. The aim of the study is to develop a mathematical model that can provide insight into the impact of thermoregulatory processes on the cardiovascular (CV) system during HD treatment. The mathematical procedure has been created by coupling a thermo-physiological model with a CV model to study regulation mechanisms in the human body during HD + UF. Model simulations for isothermal versus thermoneutral HD + UF were compared with measurement data of patients on chronic intermittent HD (n = 13). Core temperature during simulated HD + UF sessions increased within the range of measurement data (0.23°C vs. 0.32 ± 0.41°C). The model showed a decline in mean arterial pressure of -7% for thermoneutral HD + UF versus -4% for isothermal HD + UF after 200 min during which relative blood volume changed by -13%. In conclusion, simulation results of the combined model show possibilities for predicting circulatory and thermal responses during HD + UF.

Is there an association between intradialytic hypotension and serum magnesium changes?

Intradialytic hypotension (IDH) is the most common complication of hemodialysis (HD). The aim of this study was to investigate the significance of intradialytic changes of serum magnesium (sMg) and its relation to IDH. We considered 58 patients undergoing HD. Serum magnesium was measured at start, after 2 hours, and at the end of the HD sessions. Total sMg concentration corrected for albumin was according to Krolles proposed formula. Blood pressure was measured every 30 min. Data were analyzed by SPSS.15. A P value of less than 0.05 was considered as significant. Occurrence of IDH among HD patients was 27.6% (16/58). Serum magnesium decreased significantly during HD session (P<0.05). Comparing corrected sMg in IDH group with non-IDH group showed that: corrected sMg was 0.66 ± 0.14 mmol/L vs. 0.84 ± 0.26 mmol/L at the start of dialysis (P=0.43), 0.62 ± 0.17 mmol/L vs. 0.74 ± 0.23 mmol/L (P=0.04) at 2 hours, and 0.61 ± 0.12 mmol/L vs. 0.72 ± 0.22 mmol/L (P=0.03) at the end of dialysis. Intradialytic hypotension episodes were significantly related to a decrease in sMg during dialysis (P=0.02). There was a significant decrease in sMg levels during dialysis. Intradialytic hypotension was significantly related to lowered sMg levels during dialysis.

Artificial neural networks improve the prediction of Kt/V, follow-up dietary protein intake and hypotension risk in haemodialysis patients.

Artificial neural networks (ANN) represent a promising alternative to classical statistical and mathematical methods to solve multidimensional non-linear problems. The aim of the study was to compare the performance of ANN in predicting the dialysis quality (Kt/V), the follow-up dietary protein intake and the risk of intradialytic hypotension in haemodialysis patients with that predicted by experienced nephrologists. A combined retrospective and prospective observational study was performed in two Swiss dialysis units (80 chronic haemodialysis patients, 480 monthly clinical observations and biochemical test results). Using mathematical models based on linear and logistic regressions as background, ANN were built and then prospectively compared with the ability of six experienced nephrologists to predict the Kt/V and the follow-up protein catabolic rate (PCR) and to detect a Kt/V < 1.30, a follow-up PCR < 1.00 g/kg/day and the occurrence of hypotension. ANN compared with nephrologists gave a more accurate correlation between estimated and calculated Kt/V and follow-up PCR (P<0.001). The same superiority of ANN was also seen in the ability to detect a Kt/V < 1.30, a follow-up PCR < 1.00 g/kg/day and the occurrence of hypotension expressed as a percentage of correct answers, sensitivity, specificity and predictivity. The use of ANN significantly improves the ability of experienced nephrologists to estimate the Kt/V and the follow-up PCR and to detect a Kt/V < 1.30, a follow-up PCR < 1.00 g/kg/day and the occurrence of intradialytic hypotension.