Nonocclusive mesenteric infarction in hemodialysis patients

Perioperative Hypotension in Chronic Kidney Disease Patients with Dialysis Undergoing Noncardiac Surgery: A Retrospective Cohort Study

BACKGROUND

Patients with chronic kidney disease who require maintenance dialysis suffer excess morbidity and mortality for reasons that are not clearly elucidated. There are few targets for intervention to improve their outcomes. The authors hypothesized that perioperative hypotension is more common in patients receiving dialysis.

METHODOLOGY

A retrospective cohort study was conducted of adult patients who had inpatient noncardiac surgery lasting greater than 2 h with general anesthesia between January 2012 and December 2021 at the Cleveland Clinic (Cleveland, Ohio). Using International Classification of Diseases codes and dialysis documentation in the electronic medical record, was derived age, American Society of Anesthesiologists (Schaumburg, Illinois) Physical Status, surgery type, and propensity score (predicting dialysis dependence) matched groups of patients (1) with dialysis-dependent chronic kidney disease, (2) with nondialysis chronic kidney disease, and (3) without kidney disease. The primary outcomes were total area under the curve of mean arterial pressure (MAP) less than 65 mmHg during the surgery and postoperative MAP less than 70 mmHg during 48 h after surgery.

RESULTS

Three 1:1:1 matched groups of 1,886 patients (total, 5,658 patients) from an overall cohort of 123,761 were derived. Cases with dialysis-dependent kidney disease had a greater intraoperative area under the curve of MAP less than 65 mmHg (difference in medians, 18.4 mmHg-min 98.75% CI, 11.3 to 25.6; P < 0.001) when compared to patients who had nondialysis kidney disease and when compared to patients without kidney disease (difference in medians, 15.5 mmHg-min; 98.75% CI, 6.6 to 24.4; P < 0.001). Patients receiving preoperative dialysis were also more likely to have postoperative MAP less than 70 mmHg compared to patients with nondialysis kidney disease (rate ratio, 1.52; 98.75% CI, 1.48 to 1.57; P < 0.0001) and compared to patients without kidney disease (rate ratio, 1.43; 98.75% CI, 1.38 to 1.47; P < 0.0001).

CONCLUSIONS

Perioperative hypotension is more severe and common among patients who undergo chronic maintenance dialysis compared to similar patients without dialysis dependence. The management of hemodynamics in this population comes with unique considerations that warrant further systematic evaluation.

EDITOR’S PERSPECTIVE

Fulminant Non-occlusive Mesenteric Ischemia After Head Trauma: Report of Two Cases

There have been no case reports of non-occlusive mesenteric ischemia (NOMI) following head trauma. Our two patients with non-surgical traumatic intracerebral hemorrhage succumbed to NOMI one week after the injury. Both were women over age 80 years and were clinically improving before NOMI occurred. One patient had been eating since admission, while the other had not, which prompted the initiation of enteral nutrition on day 5. The patients shared many characteristics: 1) over age 80 years; 2) minor brain contusion; 3) constipation for a week; 4) minimal abdominal symptoms; 5) rapidly developing leukocytosis, hyperglycemia, hypernatremia, and elevated blood urea nitrogen; 6) massive diarrhea with a small amount of blood on the same day that laboratory data became abnormal; and 7) fever and shock developed shortly after diarrhea appeared. Because of the fulminant worsening of the condition, shock status, and old age, surgical intervention was considered high risk and not performed in either patient. In retrospect, if NOMI had been diagnosed earlier when the acute pancreatitis-like symptoms began, surgical intervention may have saved their lives. Clinicians should be aware that NOMI can occur after relatively minor head trauma, which can cause death if the diagnosis is delayed.

A Case of Nonocclusive Mesenteric Ischemia During Bioradiotherapy With Cetuximab

Nonocclusive mesenteric ischemia (NOMI) causes mesenteric ischemia and intestinal necrosis despite the absence of organic obstruction, such as thrombi and emboli in mesenteric blood vessels, and it has an extremely poor prognosis. We report a case of NOMI developed during bioradiotherapy (BRT) with cetuximab for cervical lymph node metastasis of tongue cancer. The patient was a 73-year-old man who underwent right radical neck dissection for neck lymph node metastasis after tongue cancer surgery. Postoperatively, the patient received BRT with cetuximab. On the 34th day after BRT, the patient had abdominal distension and a decreased level of consciousness. Contrast-enhanced computed tomography revealed mesenteric ischemia without thrombi and extensive intestinal emphysema. The patient was diagnosed with NOMI. Furthermore, he had septic shock and was treated with vasopressors and antibacterial agents; however, the condition of the patient did not improve, and he died on the same day.

Construction of an Early Alert System for Intradialytic Hypotension before Initiating Hemodialysis Based on Machine Learning

Introduction

Intradialytic hypotension (IDH) is prevalent and associated with high hospitalization and mortality rates. The purpose of this study was to explore the risk factors for IDH and use artificial intelligence to establish an early alert system before hemodialysis sessions to identify patients at high risk of IDH.

Materials and Methods

We obtained data on 314,534 hemodialysis sessions conducted at Sichuan Provincial People's Hospital from the renal disease treatment information system. IDH was defined as a systolic blood pressure drop ≥20 mm Hg, a mean arterial pressure drop ≥10 mm Hg during dialysis, or the occurrence of clinical hypotensive events requiring nursing intervention. After pre-processing, the data were randomly divided into training (80%) and testing (20%) sets. Four interpolation methods, three feature selection methods, and 18 machine learning algorithms were used to construct predictive models. The area under the receiver operating characteristic curve (AUC) was the main indicator for evaluating the performance of the models, while Shapley Additive ExPlanation was used to explain the contribution of each variable to the best predictive model.

Results

A total of 3,906 patients and 314,534 dialysis sessions were included, of which 142,237 cases showed IDH (incidence rate, 45.2%). Nineteen parameters were identified through artificial intelligence feature screening. They included age, pre-dialysis weight, dry weight, pre-dialysis blood pressure, heart rate, prescribed ultrafiltration, blood cell counts (neutrophil, lymphocyte, monocyte, eosinophil, lymphocyte, and platelet counts), hematocrit, serum calcium, creatinine, urea, glucose, and uric acid. Random forest, gradient boosting, and logistic regression were the three best models, and the AUCs were 0.812 (95% confidence interval [CI], 0.811-0.813), 0.748 (95% CI, 0.747-0.749), and 0.743 (95% CI, 0.742-0.744), respectively.

Conclusion

Our dialysis software-based artificial intelligence alert system can be used to predict IDH occurrence, enabling the initiation of relevant interventions.

Identifying survival protective factors for chronic dialysis patients with surgically confirmed acute mesenteric ischemia

BACKGROUND

Mesenteric ischemia is significantly more common in end-stage kidney disease patients undergoing chronic dialysis than in the general population and is associated with high morbidity and mortality. However, reports on prognostic factors in this population are limited.

AIM

To elucidate the in-hospital outcomes of acute mesenteric ischemia in chronic dialysis patients and to analyze protective factors for survival.

METHODS

The case data of 426 chronic dialysis patients who were hospitalized in a tertiary medical center for acute mesenteric ischemia over a 14-year period were retrospectively reviewed. Of these cases, 103 were surgically confirmed, and the patients were enrolled in this study. A Cox regression analysis was used to evaluate the protective factors for survival.

RESULTS

The in-hospital mortality rate among the 103 enrolled patients was 46.6%. Univariate analysis was performed to compare factors in survivors and nonsurvivors, with better in-hospital outcomes associated with a surgery delay (defined as the time from onset of signs and symptoms to operation) < 4.5 d, no shock, a higher potassium level on day 1 of hospitalization, no resection of the colon, and a total bowel resection length < 110 cm. After 1 wk of hospitalization, patients with lower white blood cell count and neutrophil counts, higher lymphocyte counts, and lower C-reactive protein levels had better in-hospital outcomes. Following multivariate adjustment, a higher potassium level on day 1 of hospitalization (HR 1.71, 95%CI 1.19 to 2.46; P = 0.004), a lower neutrophil count (HR 0.91, 95%CI 0.84 to 0.99; P = 0.037) at 1 wk after admission, resection not involving the colon (HR 2.70, 95%CI 1.05 to 7.14; P = 0.039), and a total bowel resection length < 110 cm (HR 4.55, 95%CI 1.43 to 14.29; P = 0.010) were significantly associated with survival.

CONCLUSION

A surgery delay < 4.5 d, no shock, no resection of the colon, and a total bowel resection length < 110 cm predicted better outcomes in chronic dialysis patients with acute mesenteric ischemia.

Isolated cecal necrosis: Report of two cases

Isolated cecal necrosis is a rare variant of ischemic colitis. Diagnosis is difficult because of nonspecific clinical and radiological findings. It especially affects patients with comorbidities affecting mesenteric perfusion.

Disaster Diagnoses in Geriatric Patients with Abdominal Pain

Care of geriatric patients with abdominal pain can pose significant diagnostic and therapeutic challenges to emergency physicians. Older adults rarely present with classic signs, symptoms, and laboratory abnormalities. The incidence of life-threatening emergencies, including abdominal aortic aneurysm, mesenteric ischemia, perforated viscus, and other surgical emergencies, is high. This article explores the evaluation and management of several important causes of abdominal pain in geriatric patients with an emphasis on high-risk presentations.

An update review of intradialytic hypotension: concept, risk factors, clinical implications and management

Intradialytic hypotension (IDH) is a frequent and serious complication of chronic haemodialysis, linked to adverse long-term outcomes including increased cardiovascular and all-cause mortality. IDH is the end result of the interaction between ultrafiltration rate (UFR), cardiac output and arteriolar tone. Thus excessive ultrafiltration may decrease the cardiac output, especially when compensatory mechanisms (heart rate, myocardial contractility, vascular tone and splanchnic flow shifts) fail to be optimally recruited. The repeated disruption of end-organ perfusion in IDH may lead to various adverse clinical outcomes affecting the heart, central nervous system, kidney and gastrointestinal system. Potential interventions to decrease the incidence or severity of IDH include optimization of the dialysis prescription (cool dialysate, UFR, sodium profiling and high-flux haemofiltration), interventions during the dialysis session (midodrine, mannitol, food intake, intradialytic exercise and intermittent pneumatic compression of the lower limbs) and interventions in the interdialysis period (lower interdialytic weight gain and blood pressure–lowering drugs). However, the evidence base for many of these interventions is thin and optimal prevention and management of IDH awaits further clinical investigation. Developing a consensus definition of IDH will facilitate clinical research. We review the most recent findings on risk factors, pathophysiology and management of IDH and, based on this, we call for a new consensus definition of IDH based on clinical outcomes and define a roadmap for IDH research.

The effect of BCM guided dry weight assessment on short-term survival in Chinese hemodialysis patients : Primary results of a randomized trial - BOdy COmposition MOnitor (BOCOMO) study

BACKGROUND

Lack of accurate and effective assessment tools of fluid status is one of the major challenges to reach proper dry weight (DW) in chronic hemodialysis (HD) population. The aim of this randomized study was to evaluate the effect of bioimpedance guided DW assessment on long-term outcomes in Chinese HD patients. Eligible patients were randomly assigned (1:1) to two groups in each center, the control group and body composition monitor (BCM) group. In the BCM group, DW has been evaluated by bioimpedance technic every 2 months during follow-up. The primary composite endpoint consisted of death, acute myocardial infarction, cerebral infarction, cerebral hemorrhage, and peripheral vascular disease.

METHODS

A total of 445 patients were recruited from 11 hemodialysis centers from Beijing, Tianjin and Shijiazhuang cities from Jan 1, 2013 to Dec 31, 2014. They were randomized into either BCM group or control group. All patients have been followed up for 1 year or until Dec 31, 2014 or censoring.

RESULTS

At baseline, there were no significant differences between two groups in terms of demographic parameters, dialysis vintage, percentage of vascular access, and comorbid conditions. At the end of the study, 18 (4.04%) patients had died (11 in control group and 7 in BCM group). Kaplan-Meier survival analysis showed no significant difference in survival rates between two groups (log-rank test P = 0.07). However, there was an increasing trend of survival rates in BCM group compared to the control group. In the multivariable Cox analysis, there was a nonsignificant trend toward less primary composite end points in the BCM group in the adjusted analysis, the hazard ratio was impressive (0.487, 95% CI 0.217-1.091, P = 0.08).

CONCLUSION

Bioimpedance technic has been applied to assess fluid status for decades and has been proved to be a promising tool for clinical practice. Although short-term outcomes were not improved in the randomized, controlled trial, the ascending trend in survival has been observed. Further studies are needed to investigate the survival benefit of bioimpedance method in DW assessment in a larger sample with longer follow-up period.

TRIAL REGISTRATION

ClinicalTrials.org, NCT01509937. Registered 13 January 2012.

Quantitative evaluation of superior mesenteric artery calcification in hemodialysis patients undergoing aortic valve replacement

OBJECTIVE

Postoperative acute mesenteric ischemia (AMI) in the long-term hemodialysis (HD) patients could be a disastrous complication leading to high mortality. The objective is to evaluate the association between the presence of superior mesenteric artery calcification (SMAC) and early and late outcomes after aortic valve replacement (AVR) in HD patients.

METHODS

Between April 2003 and December 2018, the enrolled 46 HD patients (19 women; mean age 72 years) who underwent AVR for severe aortic valve stenosis were retrospectively reviewed. 25 patients (54.3%) who had severe calcifications of superior mesenteric artery (SMA) were defined as the SMAC group, and the calcification extent of SMA was evaluated on preoperative non-contrast CT using Agaston calcium score [calcification area (cm²) × max CT value (HU)]. The operative outcomes were compared with those of the non-SMAC group comprising 21 patients (45.7%).

RESULTS

The following factors in SMAC group were statistically higher compared with those of the non-SMAC group: age (73.6 ± 7.2 vs 69.3 ± 7.1 years; p = 0.04), celiac artery calcification (76.4% vs 17.6%; p < 0.001), calcium score of SMA (692.3 ± 300.0 vs 123.5 ± 180.7; p < 0.001), the incidence of AMI (24.0% vs 4.7%; p = 0.001), and hospital mortality (16.0% vs 0%; p = 0.02). In multivariate analysis, the presence of SMAC was significantly associated with AMI (OR 3.8, p = 0.05) and hospital mortality (OR 2.4, p = 0.02). Calcium score of SMA in patients complicated with AMI was significantly higher than those without AMI (815.7 ± 300.5 vs 366.9 ± 351.2; p < 0.01).

CONCLUSION

Quantitative evaluation of SMAC could be a predictive marker of incidence of AMI after AVR in HD patients.

Particular aspects of gastroenterological disorders in chronic kidney disease and end-stage renal disease patients: a clinically focused review

Besides renal disease, gastrointestinal (GI) disorders are frequently reported in patients with chronic kidney disease (CKD) and end-stage renal disease (ESRD). Related gastrointestinal symptoms tend to increase as the renal disease progresses. Also, in patients with ESRD, the modality of dialysis is related to particular forms of GI disorders.The kidney can interact with the digestive organs through functional endogenous systems such as the 'kidney-colon axis' and the 'kidney-liver axis'. Digestive diseases are one of the visible manifestations of the disturbance between hemostatic, hemodynamic and immunological balance in such patients.No clear management guidelines currently exist for many of the gastrointestinal problems that accompany renal failure. This review aims to describe the particular aspects of GI diseases present in CKD/ESRD. We focus our discussion in the specificities of epidemiology, diagnosis, and prognosis of such disorders between the different segments of the digestive system.

Dataset supporting blood pressure prediction for the management of chronic hemodialysis

Hemodialysis (HD) is a treatment given to patients with renal failure. Notable treatment-related complications include hypotension, cramps, insufficient blood flow, and arrhythmia. Most complications are associated with unstable blood pressure during HD. Physicians are devoted to seeking solutions to prevent or lower the incidence of possible complications. With advances in technology, big data have been obtained in various medical fields. The accumulated dialysis records in each HD session can be gathered to obtain big HD data with the potential to assist HD staff in increasing patient wellbeing. We generated a large stream of HD parameters collected from dialysis equipment associated with the Vital Info Portal gateway and correlated with the demographic data stored in the hospital information system from each HD session. We expect that the application of HD big data will greatly assist HD staff in treating intradialytic hypotension, setting optimal dialysate parameters, and even developing an intelligent early-warning system as well as providing individualized suggestions regarding dialysis settings in the future.

Clinical features and outcomes of nonocclusive mesenteric ischemia after cardiac surgery: a retrospective cohort study

Nonocclusive mesenteric ischemia after cardiac surgery is a life-threatening complication requiring emergent intervention. However, because of its rarity, the clinical features and outcomes of nonocclusive mesenteric ischemia remain unknown. The present study aimed to clarify patients' backgrounds, clinical features and mortality of nonocclusive mesenteric ischemia after cardiac surgery, using a Japanese national inpatient database. We identified patients undergoing cardiac or thoracic aortic surgery between July 2010 and March 2017, using the Japanese Diagnosis Procedure Combination database. We calculated the incidence proportion of nonocclusive mesenteric ischemia and examined treatment options (bowel resection and interventional radiology) and patients' discharge status (in-hospital mortality and destination of discharge). We identified 221,900 eligible patients to find 568 (0.26%) patients with bowel ischemia in the same admission. Of these, 124 (0.06%) patients developed nonocclusive mesenteric ischemia, and in-hospital mortality after nonocclusive mesenteric ischemia was 77%. Treatment options for nonocclusive mesenteric ischemia included bowel resection alone (n = 34), interventional radiology (n = 15), or both (n = 15); 27, 10, and 8 patients died, respectively. Seven patients (5.6%) were discharged to home. Among 60 patients without bowel resection or interventional radiology, 50 patients died. In multivariable regression analysis, older age, preoperative hemodialysis, preoperative circulatory support, and hypothermic cardiopulmonary bypass were associated with NOMI. The present study showed that nonocclusive mesenteric ischemia after cardiac surgery was very rare. Mortality following nonocclusive mesenteric ischemia was very high even if patients underwent bowel resection or interventional radiology.

Revascularization Strategies in Patients with Chronic Kidney Disease and Acute Coronary Syndromes

PURPOSE OF REVIEW

Chronic kidney disease (CKD) is a highly prevalent condition that increases the incidence and complexity of acute coronary syndrome (ACS). The purpose of this review is to summarize current evidence, uncertainties, and opportunities in the management of patients with CKD and ACS, with a focus on revascularization.

RECENT FINDINGS

Patients with CKD have been systematically under-represented or excluded from clinical trials in ACS. Available data, however, demonstrates that although patients with CKD and ACS benefit from revascularization, they are also less likely to receive recommended medical and revascularization therapies when compared to patients with normal kidney function. Despite the increased short-term risk of major morbidity and mortality, patients with CKD and ACS should be considered for an early invasive strategy while also trying to mitigate the risks of procedural related complications. Until evidence emerges from randomized clinical trials, the decision about revascularization strategy should involve multi-disciplinary collaboration, heart team consensus, and patient shared decision-making.

Non-occlusive mesenteric ischaemia associated with anorexia nervosa

Non-occlusive mesenteric ischaemia (NOMI) is a life-threatening condition that requires emergent intervention and anorexia nervosa is a chronic eating disorder that requires careful medical and nutritional management. A 54-year-old woman with a history of anorexia nervosa and undergoing chronic haemodialysis developed abdominal pain and called an ambulance. On arrival, she was in shock and abdominal examination was consistent with diffuse peritonitis. Computed tomography scan suggested ischaemia from the distal ileum to the ascending colon. Emergency laparotomy revealed NOMI from the distal ileum to the transverse colon. The treatment strategy included staged operations and careful medical management to optimise nutritional support and electrolyte management with survival of the patient. NOMI and anorexia nervosa are both difficult to manage. Meticulous interdisciplinary management can result in a good outcome.

Hepato-splanchnic circulatory stress: An important effect of hemodialysis

The gastro-intestinal tract is being increasingly recognized as the site of key pathophysiological processes in the hemodialysis patient. Intestinal dysbiosis, increased intraluminal toxin production, and increased intestinal permeability are commonly observed processes which contribute to the pathogenesis of cardiovascular disease and thus elevated mortality. The acute circulatory effects of dialysis itself may contribute significantly to the development of gastrointestinal dysfunction as a result of both local and distant effects. Additionally, the liver, a relatively unknown entity in this process, has a substantial role as a functional barrier between the portal and systemic circulation and in the metabolism of pathogenic gut-derived uremic toxins. Here we summarize the evidence for acute gastro-intestinal and hepatic effects of hemodialysis and identify gaps in knowledge to date which require further study.

The Relationship between Intradialytic Hypotension and Hospitalized Mesenteric Ischemia: A Case-Control Study

BACKGROUND AND OBJECTIVES

Mesenteric ischemia is a rare but devastating condition caused by insufficient blood supply to meet the demands of intestinal metabolism. In patients with ESKD, it can be difficult to diagnose and has a >70% mortality rate. Patients on hemodialysis have a high prevalence of predisposing conditions for mesenteric ischemia, but the contribution of intradialytic hypotension, a potential modifiable risk factor, has not been well described.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

We used data from the US Renal Data System to identify 626 patients on hemodialysis with a hospitalized mesenteric ischemia event (cases). We selected 2428 controls in up to a 1:4 ratio matched by age, sex, black race, incident dialysis year, diabetes mellitus, coronary artery disease, and peripheral artery disease. We used six different definitions of intradialytic hypotension on the basis of prior studies, and categorized patients as having had intradialytic hypotension if ≥30% of hemodialysis sessions in the 30 days before the event met the specified definition.

RESULTS

The proportion of patients with intradialytic hypotension varied depending on its definition: from 19% to 92% of cases and 11% to 94% of controls. Cases had a higher adjusted odds (1.82; 95% confidence interval, 1.47 to 2.26) of having had intradialytic hypotension in the preceding 30 days than controls when using nadir-based intradialytic hypotension definitions such as nadir systolic BP <90 mm Hg. To examine a potential dose-response association of intradialytic hypotension with hospitalized mesenteric ischemia, we categorized patients by the proportion of hemodialysis sessions having intradialytic hypotension, defined using the Nadir90 definition (0%, 1%-9%, 10%-29%, 30%-49%, and ≥50%), and found a direct association of proportion of intradialytic hypotension with hospitalized mesenteric ischemia (P-trend<0.001).

CONCLUSIONS

Patients with hospitalized mesenteric ischemia had significantly higher odds of having had intradialytic hypotension in the preceding 30 days than controls, as defined by nadir-based definitions.

Occurrence and severity of non-occlusive mesenteric ischemia (NOMI) after cardiovascular surgery correlate with preoperatively assessed FGF-23 levels

Purpose

To evaluate the value of preoperatively assessed fibroblast growth factor 23 (FGF-23) levels and to correlate FGF-23 with angiographic findings in non-occlusive mesenteric (NOMI) ischemia using a standardized scoring system.

Materials and methods

Between 2/2011 and 3/2012 a total of 865 patients (median age: 67 years) underwent cardiovascular surgery during this ethics committee approved, prospective study. 65 of these patients had clinical suspicion of NOMI and consequently underwent catheter angiography of the superior mesenteric artery. Images were assessed using a standardized reporting system (Homburg-NOMI-Score). These data were correlated to following preoperative parameters of kidney function: cystatin C, creatinine, FGF-23 and estimated glomerular filtration rate (eGFR), and outcome data (death, acute renal failure) using linear and logistic regressions, as well as nonparametric tests.

Results

Significant correlations were found between FGF-23 and the angiographic appearance of NOMI (p = 0.03). Linear regression analysis showed no significant correlation to the severity of NOMI with creatinine (p = 0.273), cystatin C (p = 0.484), cystatin C eGFR (p = 0.914) and creatinine eGFR (p = 0.380). Logistic regression revealed a significant correlation between death and the Homburg-NOMI-Score (p<0.001), but not between development of NOMI and acute renal failure (p = 0.122). The ROC Analysis yielded an area under the curve of 0.695 (95% CI: 0.627–0.763) with a sensitivity of 0.672 and specificity of 0.658.

Conclusions

FGF-23 significantly correlates with the severity of NOMI, which is in contrast to other renal function parameters. The applied scoring system allows to predict mortality in NOMI patients.

Coronary Artery Bypass Surgery in End-Stage Renal Disease Patients

The number of patients requiring hemodialysis is continuously increasing around the world. Hemodialysis affects patient quality of life and it is also associated with a higher risk for cardiovascular events. In addition to traditional risk factors for cardiovascular events such as hypertension, hyperlipidemia, and diabetes, hemodialysis is associated with hyperphosphatemia, chronic inflammation, vascular calcification, and anemia which accelerate atherosclerosis, vascular stiffness, and cardiac ischemia. Treatment strategy for coronary revascularization in this progressive disease remains controversial. However, a systematic treatment including medical therapy and complete revascularization through a less invasive strategy should be considered in addressing this problem. This review discusses the epidemiology, vascular pathology and current treatment options in patients with end-stage renal disease requiring coronary revascularization.

Non-occlusive mesenteric ischemia localized in the transverse colon: a case report

Background

Non-occlusive mesenteric ischemia (NOMI) is ischemia of the mesentery that is caused by hypoperfusion or vasospasm without any thrombosis. NOMI is difficult to diagnose by physical examination alone. Although angiographic examination of the superior mesenteric artery (SMA) is the usual diagnostic method used, it is an invasive examination. Usually, a long range of the bowel becomes discontinuously necrotic in NOMI. Here, we report a rare case of NOMI localized in the transverse colon that was diagnosed by computed tomography (CT) angiography which is a minimally invasive examination.

Case presentation

A 72-year-old woman was referred to our hospital for further treatment of abdominal pain that developed 1 day before presentation. Contrast-enhanced abdominal CT scan revealed attenuated enhancement of the transverse colon. CT angiography showed SMA irregularities due to vasospasm. The middle colic artery could not be detected by CT angiography. No occlusion due to thrombus or embolism in the SMA and superior mesenteric vein was observed. Based on the findings, NOMI was suspected, and emergency laparotomy was performed, which revealed a segmentally necrotic transverse colon. The necrotic bowel was resected, and stomas were created.

Conclusion

The presence of hypotension in the patient necessitated the use of CT angiography, which proved very useful in the early diagnosis of the present case. Thus, if intestinal ischemia is suspected, even in case of a short segment, CT angiography should be performed.

Ischemic Bowel Syndrome in Patients with Spinal Cord Injury: A Nationwide Study

Purpose

The aim of this study was to determine whether spinal cord injuries (SCI) is associated with increased risk of ischemic bowel syndrome (IBS) in an Asian population by analyzing data from the National Health Insurance Research Database (NHIRD) in Taiwan.

Methods

Patients aged ≥20 years in the inpatient database with newly identified SCI from 2000 to 2011 were selected as the SCI cohort. For the non-SCI cohort, patients were selected based on a 1:4 risk-set sampling. Hospitalization with a new diagnosis of IBS during the follow-up was the main outcome measure. We used the standard univariable and multivariable Cox proportional hazard regression models to determine adjusted subhazard ratios (SHR) and 95% confidence interval (CI) in the SCI and non-SCI cohorts.

Results

Patients with SCI were at significant risk for IBS, with an adjusted SHR (aSHR) of 1.25, 95% CI = 1.04–1.51. Multivariable analysis showed individuals with SCI were associated with a greater risk of IBS than individuals without SCI among males (aSHR = 1.47, 95% CI = 1.16–1.86), all age groups (≤49 y: aSHR = 2.15, 95% CI = 1.24–3.74; 50–65 y: aSHR = 1.82, 95% CI = 1.15–2.88; >65 y: aSHR = 1.39, 95% CI = 1.11–1.74) and those without comorbidities (aSHR = 1.41, 95% CI = 1.04–1.93). Comorbidities including diabetes, hypertension, heart failure, coronary artery disease (CAD), Stroke, and end stage renal disease (ESRD) significantly increased the risk of IBS.

Conclusion

Patients hospitalized for SCI have increased risks of developing IBS. Though the mechanism that predisposes SCI patients to IBS is unclear, we suggest that physicians promptly identify and treat correctable risk factors.

Dialytic hemodynamics are associated with changes in gait speed

INTRODUCTION

Functional impairment and reduced mobility are prevalent in patients on chronic hemodialysis (HD). The impact of HD on physical performance and mobility needs evaluation.

METHODS

We measured gait speed in a cohort of chronic HD patients both pre and post an HD session. We collected demographic and laboratory data and dialytic hemodynamic parameters for the HD session. Participants completed the Falls Efficacy Scale International (FES-I) survey to assess concern for falling. We used linear regression analysis to tests for associations between our predictor variables of intra-dialytic hemodynamic change and change in gait speed from pre to post HD (primary outcome) and FES-I score (secondary outcome).

FINDINGS

Twenty-eight participants completed the study. The mean (SD) age was 64.0 (10.5) years. The majority were male (71.4%), had hypertension (85.7%) and diabetes (57.1%). The mean (SD) change in gait speed from pre to post dialysis was -0.06 (0.08) m/s. A greater decrease in gait speed was associated with greater decrease in SBP and DBP from pre to post HD (p = 0.02 and p = 0.04, respectively) and greater maximum drop in SBP and DBP during HD (p = 0.01 and p <0.01, respectively). The association between maximum drop in SBP and DBP and gait speed remained significant after adjustment for covariates. There was no association between BP change and FES-I score.

DISCUSSION

Our results suggest that HD patients who have greater decrease in BP during HD are at risk for decreased gait speed post HD.

Diagnosis of non-occlusive acute mesenteric ischemia in the intensive care unit

Background

Non-occlusive mesenteric ischemia (NOMI) is a common complication and accounts for a major cause of death in critically ill patients. The diagnosis of NOMI with respect to the eventual indications for surgical treatment is challenging. We addressed the performance of the diagnostic strategy of NOMI in the intensive care unit, with emphasis on contrast-enhanced abdominal CT-scan.

Methods

This was a retrospective monocenter study. Patients with clinically suspected acute mesenteric ischemia were included if a comprehensive diagnostic workup was carried out including surgical and/or endoscopic digestive explorations. Patients with evidence of occlusive mesenteric ischemia were excluded. A definite diagnosis of NOMI only relied on surgical or endoscopic findings. Abdominal CT-scans were reviewed by two radiologists blinded from the final diagnosis.

Results

A diagnosis of NOMI could be definitely confirmed or ruled out through surgical or endoscopic explorations of the digestive tract in 147 patients. With respect to their clinical characteristics, only a history of atrial fibrillation was an independent predictor of NOMI (odds ratio 8.3, 95% confidence interval 2.0–35.2, p = 0.004). Among them, 114 patients (75 with and 39 without NOMI) had previously been subjected to contrast-enhanced abdominal CT-scan. Portal venous gas, pneumatosis intestinalis and, to a lesser extent, abnormal contrast-induced bowel wall enhancement were poorly sensitive, but exhibited good specificities of 95, 85 and 71%, respectively. Nineteen out of 75 patients (25.3%) without any suggestive radiological signs finally exhibited mesenteric ischemia, including ten with intestinal necrosis.

Conclusions

The performance of abdominal CT-scan for the diagnosis of NOMI is limited. Radiological signs of advanced-stage ischemia are good predictors of definite mesenteric ischemia, while their absence should not be considered sufficient to rule out the diagnosis.

Electronic supplementary material

The online version of this article (doi:10.1186/s13613-016-0213-x) contains supplementary material, which is available to authorized users.

Computer Aided Detection System for Prediction of the Malaise during Hemodialysis

Monitoring of dialysis sessions is crucial as different stress factors can yield suffering or critical situations. Specialized personnel is usually required for the administration of this medical treatment; nevertheless, subjects whose clinical status can be considered stable require different monitoring strategies when compared with subjects with critical clinical conditions. In this case domiciliary treatment or monitoring can substantially improve the quality of life of patients undergoing dialysis. In this work, we present a Computer Aided Detection (CAD) system for the telemonitoring of patients' clinical parameters. The CAD was mainly designed to predict the insurgence of critical events; it consisted of two Random Forest (RF) classifiers: the first one (RF₁) predicting the onset of any malaise one hour after the treatment start and the second one (RF₂) again two hours later. The developed system shows an accurate classification performance in terms of both sensitivity and specificity. The specificity in the identification of nonsymptomatic sessions and the sensitivity in the identification of symptomatic sessions for RF₂ are equal to 86.60% and 71.40%, respectively, thus suggesting the CAD as an effective tool to support expert nephrologists in telemonitoring the patients.

Recent advances in near-infrared fluorescence-guided imaging surgery using indocyanine green

Near-infrared (NIR) fluorescence imaging has better tissue penetration, allowing for the effective rejection of excitation light and detection deep inside organs. Indocyanine green (ICG) generates NIR fluorescence after illumination by an NIR ray, enabling real-time intraoperative visualization of superficial lymphatic channels and vessels transcutaneously. The HyperEye Medical System (HEMS) can simultaneously detect NIR rays under room light to provide color imaging, which enables visualization under bright light. Thus, NIR fluorescence imaging using ICG can provide for excellent diagnostic accuracy in detecting sentinel lymph nodes in cancer and microvascular circulation in various ischemic diseases, to assist us with intraoperative decision making. Including HEMS in this system could further improve the sentinel lymph node mapping and intraoperative identification of blood supply in reconstructive organs and ischemic diseases, making it more attractive than conventional imaging. Moreover, the development of new laparoscopic imaging systems equipped with NIR will allow fluorescence-guided surgery in a minimally invasive setting. Future directions, including the conjugation of NIR fluorophores to target specific cancer markers might be realistic technology with diagnostic and therapeutic benefits.

Intradialytic Blood Pressure Abnormalities: The Highs, The Lows and All That Lies Between

BACKGROUND

Frequent blood pressure (BP) measurements are necessary to ensure patient safety during hemodialysis treatments. Intradialytic BPs are not optimal tools for hypertension diagnosis and cardiovascular risk stratification, but they do have critical clinical and prognostic significance. We present evidence associating intradialytic BP phenomena including fall, rise and variability with adverse clinical outcomes and review related pathophysiologic mechanisms and potential management strategies.

SUMMARY

Observational studies demonstrate associations between intradialytic hypotension, hypertension and BP variability and mortality. Lack of consensus regarding diagnostic criteria has hampered data synthesis, and prospective studies investigating optimal management strategies for BP phenomena are lacking. Mechanistic data suggest that cardiac, gut, kidney and brain ischemia may lie on the causal pathway between intradialytic hypotension and mortality, and endothelial cell dysfunction, among other factors, may be an important mediator of intradialytic hypertension and adverse outcomes. These plausible pathophysiologic links present potential therapeutic targets for future inquiry. The phenomenon of intradialytic BP variability has not been adequately studied, and practical clinical measures and treatment strategies are lacking.

KEY MESSAGES

Intradialytic BP phenomena have important prognostic bearing. Clinical practice guidelines for both intradialytic hypotension and hypertension exist, but their underlying evidence is weak overall. Further research is needed to develop consensus diagnostic criteria for intradialytic hypotension, hypertension and BP variability and to elucidate optimal treatment and prevention strategies for each BP manifestation.

Effect of fluid loading on left ventricular volume and stroke volume variability in patients with end-stage renal disease: a pilot study

Purpose

The aim of this study was to investigate fluid loading-induced changes in left ventricular end-diastolic volume (LVEDV) and stroke volume variability (SVV) in patients with end-stage renal disease (ESRD) using real-time three-dimensional transesophageal echocardiography and the Vigileo-FloTrac system.

Patients and methods

After obtaining ethics committee approval and informed consent, 28 patients undergoing peripheral vascular procedures were studied. Fourteen patients with ESRD on hemodialysis (HD) were assigned to the HD group and 14 patients without ESRD were assigned to the control group. Institutional standardized general anesthesia was provided in both groups. SVV was measured using the Vigileo-FloTrac system. Simultaneously, a full-volume three-dimensional transesophageal echocardiography dataset was acquired to measure LVEDV, left ventricular end-systolic volume, and left ventricular ejection fraction. Measurements were obtained before and after loading 500 mL hydroxyethyl starch over 30 minutes in both groups.

Results

In the control group, intravenous colloid infusion was associated with a significant decrease in SVV (13.8%±2.6% to 6.5%±2.6%, P<0.001) and a significant increase in LVEDV (83.6±23.4 mL to 96.1±28.8 mL, P<0.001). While SVV significantly decreased after infusion in the HD group (16.2%±6.0% to 6.2%±2.8%, P<0.001), there was no significant change in LVEDV.

Conclusion

Our preliminary data suggest that fluid responsiveness can be assessed not by LVEDV but also by SVV due to underlying cardiovascular pathophysiology in patients with ESRD.

Shenfu injection for intradialytic hypotension: a systematic review and meta-analysis

Objective. To evaluate the effectiveness and safety of Shenfu injection (SFI) for intradialytic hypotension (IDH). Methods. A systematic review of data sources published as of April 2014 was conducted. These included the Cochrane Central Register of Controlled Trials (2014 issue 4), Pubmed, Embase, CBM, CNKI, VIP, and Wangfang Data. Randomized controlled trials (RCTs) involving SFI for treatment and prevention of IDH were identified. Two researchers independently selected articles, extracted data, assessed quality, and cross checked the results. Revman 5.2 was used to analyze the results. Results. Eight RCTs were included. The meta-analysis indicated that compared with conventional therapies alone, SFI could elevate systolic blood pressure (SBP), increase the clinical effective rate, decrease the incidence of hypotension, increase serum albumin (ALB) levels, and reduce C-reactive protein (CRP) levels without serious adverse effects. GRADE Quality of Evidence. the quality of SBP, the effective rate, ALB, and CRP were low, and hypotension incidence and DBP were very low. Conclusions. SFI is more effective than conventional therapies for prevention and treatment of IDH. However, a clinical recommendation is not warranted due to the small number of studies included and low methodology quality. Multi-center and high-quality RCTs with large sample sizes are needed to provide stronger evidence.

Isolated cecal necrosis: our surgical experience and a review of the literature

OBJECTIVE

Isolated cecal necrosis is a rare cause of ischemic colitis. Ischemic colitis is further divided into two groups: occlusive mesenteric ischemia and non-occlusive mesenteric ischemia. The aim of this study was to investigate the cause of isolated cecal necrosis.

MATERIAL AND METHODS

We operated on 3 male and 3 female patients with a mean age of 60.3±18.7 (38-85) years with a preliminary diagnosis of acute appendicitis between 2007 and 2012. Four of these patients were on hemodialysis, 1 patient had an aortofemoral bypass, and 1 patient had coronary artery disease with atrial fibrillation.

RESULTS

The diagnosis was made intraoperatively in all cases. Five patients died postoperatively. One patient survived.

CONCLUSION

In the case of right lower quadrant pain, the possibility of isolated cecal necrosis should be kept in mind, especially in patients on hemodialysis, elderly patients with diabetes, and heart disease; surgical strategies should be planned accordingly, and it should be understood that a high mortality rate will be inevitable.

Clinical outcomes and prognostic factors after surgery for non-occlusive mesenteric ischemia: a multicenter study

BACKGROUND

To date, no large-scale study has been undertaken to understand the clinical features of non-occlusive mesenteric ischemia (NOMI) after surgery. We thus performed a multicenter investigation to clarify the clinical outcomes and prognostic factors of NOMI.

PATIENTS AND METHODS

Clinical databases from 22 Japanese facilities were reviewed for evaluation of patients who received surgery for NOMI between 2004 and 2012. NOMI patients (n = 51) were divided into two groups: group I (n = 28) consisted of patients who survived, and group II (n = 23) consisted of patients who did not survived. Prognostic factors were compared between the two groups.

RESULTS

NOMI surgery represented 0.04% of the total number of operations performed in this time period. The overall mortality rate for NOMI surgery was 45%. Hemodialysis was a significant negative prognostic factor (p = 0.027). Preoperative elevation of transaminases, potassium, and white blood cell count, as well as metabolic acidosis and colon ischemia was poor prognostic factors. The mean Physiological and Operative Severity Score for the enumeration of Mortality and Morbidity (POSSUM) score of group I versus group II was 54.5 ± 3.6 and 85.2 ± 4.1, respectively (p < 0.001).

CONCLUSIONS

Currently, NOMI surgery has a 45% mortality rate. POSSUM scores can be used to predict the clinical outcome of patients who receive NOMI surgery.

Transient extensive hepatic portal venous gas following hypotension in a dialysis patient

A 68-year-old woman developed abdominal pain during a haemodialysis session and was transferred to our hospital. Although initial CT scan at former hospital detected extensive hepatic portal venous gas (HPVG), repeated CT scan on admission performed 2 h after the initial scan demonstrated a marked decrease in HPVG. Although HPVG is associated in some cases with bowel necrosis and high mortality, HPVG completely resolved within 18 h with only conservative treatment in presented case. Because recent increased use of CT scan allows early and highly sensitive detection of HPVG, not only in bowel necrosis, but also in non-life-threatening cases, we usually face a clinical dilemma whether to perform exploratory laparotomy. No previous studies have evaluated the duration of HPVG in detail, although this case suggests the value of CT scan follow-up in relatively stable patient even when the course of HPVG is short.

Detection of patients at high risk for non-occlusive mesenteric ischemia in hemodialysis

BACKGROUND

Nonocclusive mesenteric ischemia (NOMI) is an emerging condition in hemodialysis (HD) patients not widely studied.

MATERIALS AND METHODS

A retrospective study was conducted between 2003 and 2011. NOMI cases were recorded, and demographic, clinical, biochemical, and HD parameters were collected. This group was compared with a control group (n = 93). Risk factors, prognosis, and survival were analyzed.

RESULTS

There were 57 episodes of NOMI (incidence, 2.29 episodes per 100 patients/y). Cecum was the most frequently affected segment. Nineteen patients (33%) underwent surgery. Twenty-six patients (59%) did not survive the acute episode. Cecal damage was the only protective factor associated with mortality (relative risk [RR], 0.712; P = 0.044). The incidence of NOMI was related to erythropoietin resistance index, diabetes mellitus, and longer time on HD compared with control group (RR, 6.92, P = 0.009; RR, 9.98, P = 0.005; and RR, 1.017, P < 0.001, respectively). Mortality in survival NOMI patients was higher at 4-y follow-up compared with that in the control group (log-rank, 15.5; P < 0.0001).

CONCLUSIONS

NOMI is associated with erythropoietin resistance index, diabetes mellitus, and longer time on HD. Hypotension must be avoided in these high-risk patients to prevent NOMI.

A randomized controlled trial of long term effect of BCM guided fluid management in MHD patients (BOCOMO study): rationales and study design

BACKGROUND

Bioimpedance analysis (BIA) has been reported as helpful in identifying hypervolemia. Observation data showed that hypervolemic maintenance hemodialysis (MHD) patients identified using BIA methods have higher mortality risk. However, it is not known if BIA-guided fluid management can improve MHD patients' survival. The objectives of the BOCOMO study are to evaluate the outcome of BIA guided fluid management compared with standard care.

METHODS

This is a multicenter, prospective, randomized, controlled trial. More than 1300 participants from 16 clinical sites will be included in the study. The enrolment period will last 6 months, and minimum length of follow-up will be 36 months. MHD patients aged between 18 years and 80 years who have been on MHD for at least 3 months and meet eligibility criteria will be invited to participate in the study. Participants will be randomized to BIA arm or control arm in a 1:1 ratio. A portable whole body bioimpedance spectroscopy device (BCM-Fresenius Medical Care D GmbH) will be used for BIA measurement at baseline for both arms of the study. In the BIA arm, additional BCM measurements will be performed every 2 months. The primary intent-to-treat analysis will compare outcomes for a composite endpoint of death, acute myocardial infarction, stroke or incident peripheral arterial occlusive disease between groups. Secondary endpoints will include left ventricular wall thickness, blood pressure, medications, and incidence and length of hospitalization.

DISCUSSIONS

Previous results regarding the benefit of strict fluid control are conflicting due to small sample sizes and unstable dry weight estimating methods. To our knowledge this is the first large-scale, multicentre, prospective, randomized controlled trial to assess whether BIS-guided volume management improves outcomes of MHD patients. The endpoints of the BOCOMO study are of utmost importance to health care providers. In order to obtain that aim, the study was designed with very careful important considerations related to the endpoints, sample size, inclusion criteria, exclusion criteria and so on. For example, annual mortality of Beijing MHD patients was around 10%. To reach statistical significance, the sample size will be very large. By using composite endpoint, the sample size becomes reasonable and feasible. Limiting inclusion to patients with urine volume less than 800 ml/day the day before dialysis session will limit confounding due to residual renal function effects on the measured parameters. Patients who had received BIS measurement within 3 months prior to enrolment are excluded as data from such measurements might lead to protocol violation. Although not all patients enrolled will be incident patients, we will record the vintage of dialysis in the multivariable analysis.

Mesenteric ischemia in patients with end-stage renal disease: a nationwide longitudinal study

BACKGROUND AND AIMS

Mesenteric ischemia is an uncommon disorder associated with an extremely high mortality rate. Only limited studies have evaluated this lethal disease among patients with end-stage renal disease (ESRD). The objective of this study was to evaluate the risks of mesenteric ischemia among ESRD patients and compare the incidence between two dialysis modalities.

METHODS

Records of all ESRD patients older than 20 years of age from 1998 to 2007 and a control group consisting of 1 million records were retrieved from the Taiwan National Health Insurance Research Database. Hospitalizations for mesenteric ischemic events were retrieved using ICD-9-CM diagnosis codes and ICD-9-CM operation codes from inpatient claims.

RESULTS

Among 55,807 incident ESRD patients who received hemodialysis or peritoneal dialysis, there were 458 mesenteric ischemic events, corresponding to an incidence rate of 2.7 per 1,000 patient-years. Multivariate Cox regression analysis indicated that the independent risk factors were old age (HR 1.42 per 10 years), diabetes (HR 2.85), peripheral vascular disease (HR 2.66), atrial fibrillation (HR 2.15), heart failure (HR 1.65), chronic pulmonary disease (HR 1.41), neoplasm (HR 1.54), peptic ulcer disease (HR 1.86), and peritoneal dialysis (HR 1.51, all p < 0.05). There was no effect of dialysis modality on the mesenteric ischemia mortality rate.

CONCLUSION

The risk of mesenteric ischemia for ESRD patients was 44.1 (95% confidence interval 13.4-106.2, p < 0.001) times higher than that of the general population. Compared to hemodialysis, peritoneal dialysis was associated with a higher risk of mesenteric ischemia.

Non-obstructive mesenteric ischemia: a potentially lethal complication after cardiovascular surgery: report of two cases

We report two cases of non-obstructive mesenteric ischemia (NOMI), a rare but potentially lethal complication after cardiovascular surgery, which was successfully managed. In both cases (a 74-year-old chronic hemodialysis patient who underwent emergency aortic valve replacement and coronary artery bypass graft (CABG), and a 74-year-old patient who underwent emergency abdominal aortic aneurysm operation), NOMI occurred early postoperatively (on day 8 and 22, respectively). They suffered from severe abdominal pain, confusion, and metabolic acidosis. Contrast-enhanced multi-detector CT (MDCT) scan and subsequent selective mesenteric angiography revealed characteristic signs of NOMI, for which selective papaverine infusion through the angiography catheter was performed. It was effective in both cases to halt progressive bowel ischemia and bided our time to perform a hemicolectomy of the necrotic segment. Contrast-enhanced MDCT scan and subsequent selective angiography are vital for diagnosis. If the condition does not improve after selective papaverine infusion, exploratory laparotomy and resection of necrotic intestinal segment should be performed immediately.

The risks of high ultrafiltration rate in chronic hemodialysis: implications for patient care

As dialytic practice has evolved, hemodialysis (HD) adequacy has come to be defined in terms of small molecule clearance. A growing body of evidence suggests that fluid dynamics, specifically ultrafiltration rate (UFR), bear clinical and physiological significance and should perhaps play a more central role in titrating HD therapy. Three recent studies have shown an independent association between higher UFR and mortality. Further work is needed to determine whether this relationship represents a direct toxic effect of rapid fluid perturbations or whether this association is a consequence of confounding on the basis of large interdialytic weight gain, as each would prompt a different therapeutic response. This mounting evidence builds the case that fluid management should play a more central role in the dialytic prescription and that more individualized approaches to fluid management should be encouraged.

[Diagnosis and management of acute mesenteric ischemia]

The prevalence of significant splanchnic arterial stenoses is increasing, but remains mostly asymptomatic due to abundant collateral circulation. Acute insufficiency of mesenteric arterial blood flow accounts for 60 to 70% of cases of mesenteric ischemia and results mostly from a superior mesenteric embolus. Despite major advances have been achieved in understanding the pathogenic mechanisms of bowel ischemia, its prognosis remains dismal with mortality rates about 60%. The diagnosis of acute mesenteric ischemia depends upon a high clinical suspicion, especially in patients with known risk factors. Rapid diagnosis is essential to prevent intestinal infarction. However, early signs and symptoms of mesenteric ischemia are non specific, and definitive diagnosis often requires radiologic examinations. Early and liberal implementation of angiography has been the major advance over the past 30 years which allowed increasing diagnostic accuracy of acute mesenteric ischemia. CT and MR-based angiographic techniques have emerged as alternatives less invasive and more accurate to analyse splanchnic vessels and evaluate bowel infarction. The goal of treatment of patients with acute mesenteric ischemia is to restore intestinal oxygenation as quickly as possible after initial management that includes rapid hemodynamic monitoring and support. Surgery should not be delayed in patients suspected of having intestinal necrosis.

Rapid fluid removal during dialysis is associated with cardiovascular morbidity and mortality

Patients receiving hemodialysis have high rates of cardiovascular morbidity and mortality that may be related to the hemodynamic effects of rapid ultrafiltration. Here we tested whether higher dialytic ultrafiltration rates are associated with greater all-cause and cardiovascular mortality, and hospitalization for cardiovascular disease. We used data from the Hemodialysis Study, an almost-7-year randomized clinical trial of 1846 patients receiving thrice-weekly chronic dialysis. The ultrafiltration rates were divided into three categories: up to 10 ml/h/kg, 10-13 ml/h/kg, and over 13 ml/h/kg. Compared to ultrafiltration rates in the lowest group, rates in the highest were significantly associated with increased all-cause and cardiovascular-related mortality with adjusted hazard ratios of 1.59 and 1.71, respectively. Overall, ultrafiltration rates between 10-13 ml/h/kg were not associated with all-cause or cardiovascular mortality; however, they were significantly associated among participants with congestive heart failure. Cubic spline interpolation suggested that the risk of all-cause and cardiovascular mortality began to increase at ultrafiltration rates over 10 ml/h/kg regardless of the status of congestive heart failure. Hence, higher ultrafiltration rates in hemodialysis patients are associated with a greater risk of all-cause and cardiovascular death.

Morbidity and mortality following colorectal surgery in patients with end-stage renal failure: a population-based study

PURPOSE

The risk of abdominal surgery in patients with end-stage renal failure is poorly defined. Our objective was to describe outcomes of colorectal surgery in dialysis patients from a population-based perspective.

METHODS

We analyzed the 1993 to 2007 Nationwide Inpatient Sample to identify patients hospitalized for colorectal surgery. The effect of renal failure on mortality, complications, length of stay, and charges was evaluated using logistic regression models.

RESULTS

Between 1993 and 2007, there were 755,343 admissions for colorectal surgery in the Nationwide Inpatient Sample database; 5806 patients (0.77%) were receiving dialysis treatment (87.4% hemodialysis, 4.9% peritoneal dialysis, 7.7% method not specified). Patients undergoing dialysis had an increased risk of mortality (22.1% vs 2.8%; adjusted OR 4.83; 95% CI 4.58-5.31) and complications (52.1% vs 34.0%; adjusted OR 2.04; 95% CI 1.90-2.17). Dialysis patients undergoing nonelective procedures had a 2-fold higher mortality rate than patients having had elective surgery (25.5% vs 10.3%; adjusted OR 2.01; 95% CI 1.65-2.43). In nonelective surgery, independent predictors of mortality included procedures with an end-stoma (adjusted OR 1.86; 95% CI 1.58-2.18), age over 60 (adjusted OR 1.73; 95% CI 1.43-2.08), total colectomy (adjusted OR 1.68; 95% CI 1.27-2.22), vascular insufficiency as surgical indication (adjusted OR 1.58; 95% CI 1.32-1.90), nonprivate insurance coverage (adjusted OR 1.38; 95% CI 1.07-1.77) and malnutrition (adjusted OR 1.26; 95% CI 1.01-1.59).

CONCLUSIONS

Patients receiving dialysis treatment have an increased risk of morbidity and mortality following colorectal surgery. Elective procedures are associated with a 10% rate of mortality in this population. Dialysis patients are especially susceptible to infectious and pulmonary complications after colorectal resection. Additional studies are necessary to refine risk stratification in this high-risk patient population.

Gastrointestinal disorders and renal failure: exploring the connection

Gastrointestinal complications are known to commonly occur in patients with renal failure. Uremia and dialysis have long been speculated to increase the risk of lesions in the gastrointestinal tract and accessory organs. In addition, gastrointestinal procedures such as gastrointestinal bypass surgery and the administration of colonoscopy preparations can lead to the development of renal complications. Results from studies that have attempted to define the association between renal dysfunction and gastrointestinal complications are, however, conflicting and limited by small and varied sample populations. No clear management guidelines currently exist for many of the gastrointestinal problems that accompany renal failure. This Review examines the existing data on gastrointestinal complications in patients with chronic kidney disease and end-stage renal disease and aims to outline the etiology and management of common gastrointestinal disorders in such patients.