Venous Needle Dislodgement Research Articles

Automation and innovation in home hemodialysis machines.

In this review, we discuss the timeline of innovation and technologic development in home hemodialysis (HHD) in the United States and the legislative approvals that accompanied them. The most recently FDA-approved home hemodialysis devices provide features that include on-demand and batch dialysate generation, access disconnect for venous needle dislodgement, touchscreen interface with visual and auditory prompts and animations, drop-in sterilized cartridges with prestrung tubing, hot water disinfection of tubing allowing extended-use, dialysate flow rates as high as 500 ml/min, as well as remote treatment monitoring capabilities. Furthermore, wearable/portable dialysis devices are currently under development to simplify dialysis delivery to patients with end-stage kidney disease. Home hemodialysis devices providing longitudinal hemodialysis across different clinical settings, virtual reality headsets for more personalized training, automated patient support, as well as wearable device development and innovations give hope for a future where home hemodialysis is more accessible and seamless.

The development and testing of a prototype venous needle dislodgement detection device.

Inadvertent venous needle dislodgement (VND), from graft or arterio-venular fistula, can lead to haemorrhage resulting in a serious life-threatening complication and in some cases death by exsanguination. This paper eloquently articulates the development and testing of a novel Arduino based VND detection device. The VND detector is subjected to four testing protocols to critically analyse the efficiency of VND detection within a 12-second window. Implementation of statistical analytic methods to the obtained results successfully demonstrated the VND detector's ability to detect VND within 12 seconds.

Real-Time Internet of Medical Things System for Detecting Blood Leakage during Hemodialysis Using a Novel Multiple Concentric Ring Sensor.

Venous needle dislodgement (VND) is a major healthcare safety concern in patients undergoing hemodialysis. Although VND is uncommon, it can be life-threatening. The main objective of this study was to implement a real-time multi-bed monitoring system for VND by combining a novel leakage-detection device and IoMT (Internet of Medical Things) technology. The core of the system, the Acusense IoMT platform, consisted of a novel leakage-detection patch comprised of multiple concentric rings to detect blood leakage and quantify the leaked volume. The performance of the leakage-detection system was evaluated on a prosthetic arm and clinical study. Patients with a high risk of blood leakage were recruited as candidates. The system was set up in a hospital, and the subjects were monitored for 2 months. During the pre-clinical simulation experiment, the system could detect blood leakage volumes from 0.3 to 0.9 mL. During the test of the IoMT system, the overall success rate of tests was 100%, with no lost data packets. A total of 701 dialysis sessions were analyzed, and the accuracy and sensitivity were 99.7% and 90.9%, respectively. Evaluation questionnaires showed that the use of the system after training changed attitudes and reduced worry of the nursing staff. Our results show the feasibility of using a novel detector combined with an IoMT system to automatically monitor multi-bed blood leakage. The innovative concentric-circle design could more precisely control the warning blood-leakage threshold in any direction to achieve clinical cost-effectiveness. The system reduced the load on medical staff and improved patient safety. In the future, it could also be applied to home hemodialysis for telemedicine during the era of COVID-19.

Venous Needle Dislodgement and Access-Bloodline Separation

Serious hemodialysis therapy complications are venous needle dislodgement and access-bloodline separation. In 2020, the American Nephrology Nurses Association (ANNA) brought together a task force to update the information and resources developed by the 2012 ANNA Venous Needle Dislodgement Task Force along with the development of additional resources, if needed. The 2020-2021 ANNA Venous Needle Dislodgement Task Force conducted a literature review, requested information from ANNA members, and tested taping techniques. This article discusses the results of the literature review, information requests, and taping technique testing, and provides resources on venous needle dislodgement and access-bloodline dislodgement, along with practice recommendations.

Hemodialysis taping styles and their effect on reducing the chance of venous needle dislodgement.

Vascular access complications are common among hemodialysis patients, although most are not immediately life-threatening. However, inconsistent taping techniques and incompatible detection mechanisms may lead to venous needle dislodgement (VND), which can lead to catastrophic blood loss. Taping technique does not always meet the recommended best practice and there may be no available protocol for new staff. Three commonly used taping patterns (the Chevron, butterfly, and overlapping styles) were tested in a mechanical engineering laboratory to determine the forces that each method was capable of withstanding. While all taping styles were confirmed to have an adhesive force stronger than the inherent force from the venous jet flow of blood, the overlapping style was found to have limited capability beyond this minimum criterion. Both the butterfly and Chevron styles demonstrated excellent holding capability, with elongation of dislodgement particularly noted for the butterfly style, and slightly stronger hold noted for the Chevron style. The Chevron style may be better suited to lateral movements from all directions, due to the taping direction. We recommend that either the Chevron or butterfly style is used for dialysis needle taping, with the butterfly better suited to home dialysis (where monitors may be used) and the Chevron better suited for in-care patients who may present erratic movements. The overlapping style is not recommended for use.

The Integrated Program of Needle Dislodgement Bleeding Alarm System Is Associated with a Decreased Incident of Venous Needle Dislodgement or Bleeding

The Integrated Program of Needle Dislodgement Bleeding Alarm System Is Associated with a Decreased Incident of Venous Needle Dislodgement or Bleeding

P1562IMPLEMENTATION FOR INTEGRATED PROGRAM OF HEMODIALYSIS VASCULAR ACCESS PUNCTURE TRAINING AND AN ALARM SYSTEM MAY REDUCE THE INCIDENT OF VENOUS NEEDLE DISLODGMENT AND BLEEDING

Abstract Background and Aims A puncture of vascular access is commonly used in clinical treatment, such as hemodialysis or central venous catheters. At this time, leakage or infection associated with Venous needle dislodgement(VND) is a high risk of fatality, especially for patients with restlessness, impaired cognition, isolation, or home dialysis. In general dialysis procedures, medical personnel relies on patient reports and caregivers to manually inspect the site of dialysis puncture and detect the occurrence of needle removal and blood transfusion. There are some devices for detecting the presence of needle dislodgement in the market. Still, there are no large-scale reports for the integrated program for nursing training and device implantation. This study aims to conduct a program for an integrated training course and the VND device and hopes to reduce the incidence of needle removal and blood leakage. Method This study was divided into two phases, the control phase, and the study period. In the first phase, the abnormal events of ou venous needle dislodgement and blood leakage was recorded in the hemodialysis unit room during the first three months. Before the study period, we introduced an integrated program, including the standard process of fistula puncture, care during hemodialysis, an inspection of the venous puncture site, and an alarm system. In the study period, we also conducted the standard program and collected the data of the events of venous dislodgement or bleeding. Results The control phase was conducted during the three months from July 2019 to September 2019, and the study period was performed in November 2019. A total of 62 patients completed the study. During the control period, there were a total of 2087 dialysis treatments, of which 30 patients had venous needle dislodgement or bleeding. There were a total of 70 events of venous needle dislodgement or bleeding occurred, and the incidence rate was 3.3 events per 100 sessions. After the conduction of the integrated program and implantation of the alarm system in November 2019, there were a total of 682 dialysis sessions, and 15 events of venous needle dislodgement or bleeding occurred. The incidence rate was 2.2 events per 100 courses. Conclusion This study introduced venous needle dislodgement or bleeding alarm system in the hemodialysis unit. Compared with the traditional method, after the integrated care program, including fistula puncture, care, inspection, introduction, and use of the alarm system, venous needle dislodgement or bleeding dropped from 3.3 to 2.2 per 100 sessions. Therefore, through standardized training and program, it may be related to the decrease in the incidence of venous needle dislodgement or bleeding. This training mode can be worth promoting to more dialysis units to improve the quality of patient care. More follow-up studies are needed to provide multiple evidence.

P1563THE ANALYSIS OF RISK FACTORS FOR THE PATIENTS EXPERIENCED VENOUS NEEDLE DISLODGEMENT OR BLEEDING DURING DIALYSIS

Abstract Background and Aims A puncture of vascular access is commonly used in clinical treatment, such as hemodialysis or central venous catheters. At this time, leakage or infection associated with Venous needle dislodgement(VND) is a high risk of fatality, especially for patients with restlessness, impaired cognition, isolation, or home dialysis. At present, a few studies believe that many risk factors are associated with venous needle dislodgment and bleeding, including difficult needle fixation, restlessness, unconsciousness, or abnormal movement. However, only a few studies are focusing on patient disease, medication, and other risk assessments. Therefore, this study aims to explore the risk factors of patients with venous needle dislodgment and bleeding and hope to establish the risk classification. Method This study was a prospective study conducted in the hemodialysis room of Tainan Regional Hospital. Before starting to collect the venous needle dislodgment and bleeding data, we performed a training program for medical and nursing staff, including venous puncture, fixation, puncture site assessment, and management. During the three months from July 2019 to 2019/9, we collected clinical data were collected, including patient sex, gender, diseases, records of dialysis access blockage, anticoagulant dose, and a high-risk assessment record (eight risk factors). Finally, we analyzed the data and compared the data between the two groups of patients who experienced needle dislodgement and bleeding. We applied statistical software STATA, chi_square, z-test. P<0.05 was defined as significant. Results Seventy patients were included in this study, with an average age of 63.23 (± 1.2 years) and 45 males (64.28%). In 2019 / 7-9, there were a total of 32 patients with 72 venous needle dislodgment and bleeding. The patients with the condition as below were considered high-risk patients. In terms of gender, whether it is a high risk, diabetes, high blood pressure, whether to use sleeping pills, diabetic hypotension, whether to use warfarin or to use anticoagulant doses are all not statistically significant. The proportion of patients with vascular-access and undergoing percutaneous transluminal angioplasty was 35.2% (11) in high-risk patients and 10.3% (4) in low-risk patients, p <0.01. Conclusion Before data collection in this study, a standardized training program was performed for medical care and vascular access monitoring. However, there were no new risk factors were found. This research model can provide a new direction for further research.

P1559PERFORMANCE EVALUATION OF REAL-TIME MULTI-BED MONITORING SYSTEM FOR BLOOD LEAKAGE IN DIALYSIS

Abstract Background and Aims In HD treatment, venous needle dislodgement (VND) is a major concern in healthcare systems worldwide. Although VND is not an extremely common occurrence, it could be life-threatening or even cause death. The report of the Taiwan Patient Safety Reporting System listed the dislodgement of needles, catheters, and similar devices as third among thirteen common incident types that threaten patient safety. Hospitals are jointly liable for the blood leakage and have to provide emergency treatment such as emergency hemostasis, blood transfusion, Erythropoietin (EPO) injection and hospitalization. To a worse extent, hospitals, physicians and paramedics have to face criminal charges and the claims raised by the patients’ families. This study employed digital technology to develop a real-time multi-bed monitoring system to detect fluid leakage and control the state of multi-bed blood leakage simultaneously, allowing paramedics to respond to and solve issues swiftly. The research evaluated the IoT system for the leakage detector system with multi-bed monitoring interface by clinical trials. Method Our research used the Acusense IoT platform, which is a multi-bed monitoring system that includes leakage detection device, IoT gateway, and cloud analysis system to monitor multiple HD patients in real-time. Any single IoT gateway can be utilized to pair with eight blood leakage detection devices and collects data with multi-point Bluetooth 4.2, and the information gathered by IoT gateway will be uploaded to database via WiFi. The selecting criteria for participants, who has low risk of blood leakage and the participants who did not have blood leakage within two months, were all excluded from our analysis. Before a clinical trial, 20 nurses were trained to use the leakage detection system for two times. And then we have set this platform on different areas for 1 month. For the results of blood leakage detection system in the clinical settings, we calculated accuracy, recall, precision, and averaged F score, which are the most common metrics for evaluating the performance of binary classification. Results In this study, a total of 50 subjects with an average age and standard deviation (SD) of 62.2 and 9.1 were recruited from the Tainan Municipal An-Nan Hospital (TMANH) in Taiwan. After deploying Acusense IoT platform in clinical workflow, there were a total of 682 dialysis sessions and 15 events of venous needle dislodgement or bleeding occurred of which 13 were detected by the device. The performance metrics reach 99.7% accuracy, 100% recall, 99.7% precision, and 99.9% Averaged F-measure. There are no adverse reactions to patients. It indicates that the proposed blood leakage detection system showed favorable performance, and was proven to be capable of accurately detecting blood leakage. Conclusion The blood leakage detector combined with information system realizes the multi-bed monitoring system and provides support for real-time clinical decision support system. When venous needle dislodgement happens, the monitoring system will timely warn nurse to increase the relationship between doctors and patients. It may result in the prevention of VND, and decreased hospitalization to reduce the side effects of hemodialysis.

Detection of Needle Dislodgement Using Extracorporeal Pressure Signals: A Feasibility Study.

Venous needle dislodgement (VND) during dialysis is a rarely occurring adverse event, which becomes life-threatening if not handled promptly. Because the standard venous pressure alarm, implemented in most dialysis machines, has low sensitivity, a novel approach using extracted cardiac information to detect needle dislodgement is proposed. Four features are extracted from the arterial and venous pressure signals of the dialysis machine, characterizing the mean venous pressure, the venous cardiac pulse pressure, the time delay, and the correlation between the two pressure signals. The features serve as input to a support vector machine (SVM), which determines whether dislodgement has occurred. The SVM is first trained on a set of laboratory data, and then tested on another set of laboratory data as well as on a small data set from clinical hemodialysis sessions. The results show that dislodgement can be detected after 12-17 s, corresponding to 24-143 ml blood loss. The standard venous pressure alarm used in clinical routine only detects 50% of the VNDs, whereas the novel method detects all VNDs and has a false alarm rate of 0.12 per hour, provided that the amplitude of the extracted cardiac pressure signal exceeds 1 mmHg. The results are promising; however, the method needs to be tested on a larger set of clinical data to better establish its performance.

A prototype line clamp for venous access bleeding in hemodialysis: A prospective cohort study.

Venous needle dislodgement (or venous port disconnection) during hemodialysis (HD) may lead to catastrophic blood loss, particularly during unsupervised home HD. A prototype venous line clamp was developed for use in conjunction with the Redsense blood loss sensor. We hypothesize that this prototype device will provide additional safety to dialysis without excessive burden. This was a single-center, prospective cohort study. Participants kept a log of bleeding, troubleshooting and clamp deployment events, and completed questionnaires before device first use and after device final use. The primary outcome was appropriate device function, evaluated by review of bleeding and clamp deployment events. The secondary outcomes were patient/nursing staff expectations and experience of the device. Fourteen patients used the device during a combined total of 214 HD treatments. Five participants (36%) had experienced a bleeding or disconnection event prior to study recruitment. All vascular access types were represented. The device was tested during incenter HD (n = 7 patients) and home HD (n = 7 patients). There were eight clamp deployment events, three of which were in the setting of minor bleeding at the venous access site. No other bleeding events were reported. The main troubleshooting issues were related to cumbersome device connections. Participants perceived additional safety with the device (median score 4.25 out of 5; range 1-5). However, the amount of additional work created was variable, and large in some cases (median score 2 out of 5; range 0-4.5). There was no association between HD vintage and device burden (P = 0.55). This "proof of concept" study confirmed that a clamp on the venous line, operating in conjunction with a venous access blood detector, is feasible regardless of HD location or vascular access type. The device improved patient safety perception during HD but was burdensome. Design modifications could improve future device iterations.

Diagnosis, Treatment, and Prevention of Hemodialysis Emergencies.

Given the high comorbidity in patients on hemodialysis and the complexity of the dialysis treatment, it is remarkable how rarely a life-threatening complication occurs during dialysis. The low rate of dialysis emergencies can be attributed to numerous safety features in modern dialysis machines; meticulous treatment and testing of the dialysate solution to prevent exposure to trace elements, toxins, and pathogens; adherence to detailed treatment protocols; and extensive training of dialysis staff to handle medical emergencies. Most hemodialysis emergencies can be attributed to human error. A smaller number are due to rare idiosyncratic reactions. In this review, we highlight major emergencies that may occur during hemodialysis treatments, describe their pathogenesis, offer measures to minimize them, and provide specific interventions to prevent catastrophic consequences on the rare occasions when such emergencies arise. These emergencies include dialysis disequilibrium syndrome, venous air embolism, hemolysis, venous needle dislodgement, vascular access hemorrhage, major allergic reactions to the dialyzer or treatment medications, and disruption or contamination of the dialysis water system. Finally, we describe root cause analysis after a dialysis emergency has occurred to prevent a future recurrence.

Assistive technology using integrated flexible sensor and virtual alarm unit for blood leakage detection during dialysis therapy.

Blood leakages and blood loss are both serious complications during dialysis therapies. According to dialysis survey reports, these events are life-threatening issues for nephrology nurses, medical staff, and patients. When venous needle dislodgement occurs, it takes only <2.5 min of reaction time for blood loss in an adult patient, resulting in mortality. As an early-warning design, a wireless assistive technology using an integrated flexible sensor and virtual alarm unit was developed to detect blood leakage during dialysis therapies. The flexible sensor was designed using a screen print technique with printing electronic circuits on a plastic substrate. A self-organising algorithm was used to design a virtual alarm unit, consisting of a virtual direct current grid and a virtual alarm driver. In other words, this warning device was employed to identify the blood leakage levels via wireless fidelity wireless network in cloud computing. The feasibility was verified, and commercialisation designs can also be implemented in an embedded system.

Detection of venous needle dislodgement during haemodialysis using fractional order shape index ratio and fuzzy colour relation analysis.

Venous needle dislodgement (VND) is a life-threatening complication during haemodialysis (HD) treatment. When VND occurs, it only takes a few minutes for blood loss in an adult patient. According to the ANNA (American Nephrology Nurses' Association) VND survey reports, VND is a concerning issue for the nephrology nurses/staff and patients. To ensure HD care and an effective treatment environment, this Letter proposes a combination of fractional order shape index ratio (SIR) and fuzzy colour relation analysis (CRA) to detect VND. If the venous needle drops out, clinical examinations show that both heart pulses and pressure wave variations have a low correlation at the venous anatomic site. Therefore, fractional order SIR is used to quantify the differences in transverse vibration pressures (TVPs) between the normal condition and meter reading. Linear regression shows that the fractional order SIR has a high correlation with the TVP variation. Fuzzy CRA is designed in a simple and visual message manner to identify the risk levels. A worst-case study demonstrated that the proposed model can be used for VND detection in clinical applications.

Improving patient safety and avoiding incidents in renal units

The Renal Association Patient Safety Project has identified that renal patients have been exposed to incidents and risks from failure of dialysis equipment or disposables, or from use error. Blood loss on haemodialysis, particularly from venous needle dislodgement, as well as haemolysis associated with haemodialysis, are risks for potential fatal outcomes. Solutions to these incidents and risks have been formulated and circulated, and guidelines for water treatment quality have been developed. Renal patients are susceptible to infection and also are at risk when admitted as acutely ill. Attention to the influence of ‘human factors’ on safety of renal patient care should be emphasised, especially in communication, handover and team-working. Incident reporting through hospital reporting systems within a ‘no blame’ culture is essential in order to learn from incidents. Incidents and risks related to medical devices should also be reported to the Medicines and Healthcare Products Regulatory Agency (MHRA). Sharing of incidents, risks, solutions and best practice can be rapidly achieved through the Renal Association Patient Safety Project and is being further developed in a multidisciplinary approach through collaboration with the British Renal Society and the Association of Renal Technologists.

Prevalence of Detectable Venous Pressure Drops Expected with Venous Needle Dislodgement

Venous needle dislodgement (VND) is a potentially fatal complication during hemodialysis (HD) treatment and the venous pressure monitor is the most widely used device for its detection. VND can only be detected by the venous sensor if the resulting pressure drop exceeds the difference between the actual venous pressure and the lower alarm limit. In clinical practice, the lower alarm limit is usually set 30-40mmHg below the actual venous pressure to avoid a disproportionate high number of nuisance alarms. The aim of this study was to quantify the number of fistulas and grafts in a group of HD patients where venous pressure monitoring can be expected to detect VND. We determined intra-access pressures in 99 chronic HD patients. Sixty-five (65.7%) had a fistula and 34 (34.3%) had a prosthetic graft as a vascular access. Mean intra-access pressure (Pa ) in fistulas was 32.6±23.5mmHg, whereas in grafts mean Pa was 60.9±19.5mmHg. Nineteen (29.2%) of the fistulas and 32 (94.1%) of the grafts exhibited an intra-access pressure above 40mmHg. Therefore, in our study nearly all grafts but only 29% of fistulas would fulfill the requirement for venous pressure monitoring to detect VND.

Non-cladding optical fiber is available for detecting blood or liquids

Serious accidents during hemodialysis such as an undetected large amount of blood loss are often caused by venous needle dislodgement. A special plastic optical fiber with a low refractive index was developed for monitoring leakage in oil pipelines and in other industrial fields. To apply optical fiber as a bleeding sensor, we studied optical effects of soaking the fiber with liquids and blood in light-loss experimental settings. The non-cladding optical fiber that was used was the fluoropolymer, PFA fiber, JUNFLON™, 1mm in diameter and 2m in length. Light intensity was studied with an ordinary basic circuit with a light emitting source (880nm) and photodiode set at both terminals of the fiber under certain conditions: bending the fiber, soaking with various mediums, or fixing the fiber with surgical tape. The soaking mediums were reverse osmosis (RO) water, physiological saline, glucose, porcine plasma, and porcine blood. The light intensities regressed to a decaying exponential function with the soaked length. The light intensity was not decreased at bending from 20 to 1cm in diameter. The more the soaked length increased in all mediums, the more the light intensity decreased exponentially. The means of five estimated exponential decay constants were 0.050±0.006 standard deviation in RO water, 0.485±0.016 in physiological saline, 0.404±0.022 in 5% glucose, 0.503±0.038 in blood (Hct 40%), and 0.573±0.067 in plasma. The light intensity decreased from 5V to about 1.5V above 5cm in the soaked length in mediums except for RO water and fixing with surgical tape. We confirmed that light intensity significantly and exponentially decreased with the increased length of the soaked fiber. This phenomena could ideally, clinically be applied to a bleed sensor.

Study of light transmission through gauze pad effected by blood or liquids to detect needle dislodgement

Serious accidents during hemodialysis such as a large amount of blood loss are often caused by venous needle dislodgement. To develop a bleeding sensor based on a photo sensor for monitoring the needle sites, we studied effects of liquids and porcine blood on light transmission through a thin gauze pad with a basic photo sensor. The photo sensor consisted of an ordinary electrical circuit, a light emitting diode (LED, lambda max = 645 nm), a photo diode (PD), and a thin gauze pad placed between the LED and PD that were tightly attached to the edges of a plastic clip. The light transmitted through the gauze pad, soaked with liquids or porcine blood dropped on it, was measured with a digital voltmeter. The liquids were reverse osmosis water, physiological saline, glucose in water at 5, 10, 20, 40 and 50%, porcine plasma, and porcine blood (Hct 40, 30 and 20%). The liquids on a tight-weave gauze pad, significantly increased the voltage (light transmission) from 0.412 +/- 0.003 V (SD) to 0.794 +/- 0.025 V (minimum, by reverse osmosis water) and to 0.945 +/- 0.011 V (maximum, by 50% glucose). The porcine blood significantly decreased the voltage from 0.412 to 0.195 +/- 0.030 V in Hct 40%, to 0.334 +/- 0.035 in Hct 30%, to 0.397 +/- 0.007 V in Hct 20%. The higher the concentration of glucose, the more the light transmission increased. The higher concentration of Hct, the more the light transmission decreased. Similar results were also shown for the loose-weave pad. Using two types of gauze pads, we confirmed that liquids significantly increased light transmission through gauze pad, but porcine blood decreased light transmission. This opposite response can be used to distinguish liquids from blood on a gauze pad.

A new safety device for hemodialysis

Accidental venous needle dislodgement during hemodialysis may cause serious bleeding including a sometimes fatal outcome. The venous pressure gauge of the dialysis monitor does not react when dislodgement occurs. A sensor patch put as an adhesive over the venous needle puncture site connected to an alarm unit by an optic fiber has been clinically tested in 5 dialysis departments. A small amount of blood on the sensor activates a light and sound alarm. A simple questionnaire was filled out by the nurses at each dialysis concerning their feeling of safety when the new device was used. Forty-one patients, mean age 65 years, have tested the new safety device. Two hundred test dialyses were studied, after exclusion of 13 tests. One hundred seventy-nine tests reacted positively on blood. In another 6 dialyses, a warning light appeared on the alarm unit indicating a failure in the sensor patch. Thus, the alarm functioned in 92.5% of all tests. After a small modification of the sensor patches there were only 2 dialyses (2/71) without an activated alarm on blood, i.e., 97.2% positive alarm reactions. The answers of the nurses indicated that they had an increased feeling of safety when using the new safety device, with a mean value of 3.4 points on a visual scale from 0 to 5 where 5 meant very much increased safety. In a situation when the dialysis monitors today do not react on bleedings from venous needle dislodgements, the new alarm safety device fulfils a known shortage in routine dialysis safety. In situations where supervision during a dialysis session may be insufficient as, for example, in home hemodialysis and self-care dialysis or in other situations when the patient is sleeping, the device may be life saving.

Venous needle dislodgement during hemodialysis: An unresolved risk of catastrophic hemorrhage

Venous line disconnection or needle dislodgement during hemodialysis with resultant hemorrhage is a potentially lethal event. The risk is compounded by the frequent failure of standard dialysis machines to detect the event, as blood flow through the venous needle typically creates enough back pressure to prevent venous pressure alarms even if the needle is completely out of the patient's AV access. Manufacturers are well aware of the risk and device literature contains specific warnings about it. The FDA publishes reports on its website about these events; so far this year there have been seven reported events with five deaths. Informal sources indicate that the actual (unreported) occurrence is much more frequent; we are aware of four additional events within our region alone. Efforts to reduce the risk include protocols requiring the access needles to always be visible, and use of enuresis detection devices. Anecdotal experience with these efforts suggests they are not highly effective. Protocols requiring documentation of more frequent needle site checks or alternate methods of securing the needles have not been formally evaluated. However, such efforts do not address the primary problem: there is a need for an engineered solution to this problem. Requirements for such a solution include: reliable detection of needle position and blood flow discrepancies, a useful alarm, and feedback to stop the blood pump. Persistence of this problem raises issues of regulatory oversight.