The introduction of a sound reduction bundle in the intensive care unit and its impact on sound levels and patients

BACKGROUND

ICU outcomes are continuing to improve. However, this has not been matched by similar improvements of the ICU bedspace environment, which can detrimentally impact on patient outcomes. Excessive sound and noise, especially, has been linked with adverse and potentially preventable patient outcomes and staff errors. There are many sources of sound in the ICU, with alarms from bedside equipment frequently listed as a main source. The number of alarms is increasing in parallel with the introduction of new and more sophisticated technologies to monitor and support patients. However, most alarms are not accurate or critical and are commonly ignored by staff.

OBJECTIVE

The objective of this study was to evaluate the impact of a sound reduction bundle on sound levels, number of alarms, and patients' experience and perceived quality of sleep in the ICU.

METHODS

This was a pre-post, quasi-experimental study investigating the impact of three study interventions implemented sequentially (staff education, visual warnings when sound levels exceeded the preset levels, and monitor alarm reconfigurations). Effects of staff education were evaluated using pre-education and post-education questionnaires, and the impact on patients was evaluated via self-report questionnaires. A sound-level monitor was used to evaluate changes in sound levels between interventions. Alarm audits were completed before and after alarm reconfiguration.

RESULTS

Staff knowledge improved; however, sound levels did not change across interventions. The number of monthly monitor alarms reduced from 600,452 to 115,927. No significant differences were found in patients' subjective rating of their experience and sleep.

CONCLUSION

The interventions did not lead to a sound-level reduction; however, there was a large reduction in ICU monitor alarms without any alarm-related adverse events. As the sources of sound are diverse, multidimensional interventions, including staff education, alarm management solutions, and environmental redesign, are likely to be required to achieve a relevant, lasting, and significant sound reduction.

More Frequent Use of Glucose Alarms Is Associated with Continuous Glucose Monitoring-Specific Diabetes Education: Findings from the Dia·Link Diabetes Panel

The associations of continuous glucose monitoring (CGM)-specific diabetes education with real-world utilization of glucose alerts and alarms were assessed in current CGM-users with type 1 or type 2 diabetes. A cross-sectional online survey was conducted in Germany assessing utilization (use and responses) of different alerts and alarms. Ordinal logistic regression analyses were conducted to analyze associations between utilization and participation in CGM-specific education. Data from 453 participants were analyzed (86.2% type 1 diabetes). Participants who received CGM-specific education were more likely to regularly use low-glucose alerts (odds ratio [OR] = 5.43, P < 0.001), low-glucose alarms (OR = 2.03, P = 0.027), and rate of change alerts (OR = 4.20, P = 0.009), and were more likely to immediately react to low-glucose alerts (OR = 5.23, P < 0.001) and rate of change alerts (OR = 3.75, P = 0.018). CGM-specific education has the potential to increase utilization of and response to alerts and alarms. This may help to implement more preventive elements regarding glucose management in everyday life.

Left Ventricular Assist Device Emergencies: Diagnosis and Management

Durable left ventricular assist devices (LVADs) are a virtually limitless advanced therapy option for an increasingly growing population of patients with end-stage advanced heart failure. As of 2019, 30% to 40% of all patients diagnosed with heart failure were categorized as New York Heart Association class III or IV. In 2018 more than 3.2 million office visits and 1.4 million emergency department visits carried a primary diagnosis of heart failure. Given the rapid growth of the LVAD population, facility in the diagnosis and management of common perioperative and outpatient LVAD emergencies has become of paramount importance in a variety of clinical settings.

Rehabilitation professionals' perspectives and experiences with the use of technologies for violence prevention: a qualitative study

BACKGROUND

There is growing public policy and research interest in the development and use of various technologies for managing violence in healthcare settings to protect the health and well-being of patients and workers. However, little research exists on the impact of technologies on violence prevention, and in particular in the context of rehabilitation settings. Our study addresses this gap by exploring the perceptions and experiences of rehabilitation professionals regarding how technologies are used (or not) for violence prevention, and their perceptions regarding their efficacy and impact.

METHODS

This was a descriptive qualitative study with 10 diverse professionals (e.g., physical therapy, occupational therapy, recreation therapy, nursing) who worked across inpatient and outpatient settings in one rehabilitation hospital. Data collection consisted of semi-structured interviews with all participants. A conventional approach to content analysis was used to identify key themes.

RESULTS

We found that participants used three types of technologies for violence prevention: an electronic patient flagging system, fixed and portable emergency alarms, and cameras. All of these were perceived by participants as being largely ineffective for violence prevention due to poor design features, malfunction, limited resources, and incompatibility with the culture of care. Our analysis further suggests that professionals' perception that these technologies would not prevent violence may be linked to their focus on individual patients, with a corresponding lack of attention to structural factors, including the culture of care and the organizational and physical environment.

CONCLUSIONS

Our findings suggest an urgent need for greater consideration of structural factors in efforts to develop effective interventions for violence prevention in rehabilitation settings, including the design and implementation of new technologies.

Multisensory alarm to benefit alarm identification and decrease workload: a feasibility study

The poor design of conventional auditory medical alarms has contributed to alarm desensitization, and eventually, alarm fatigue in medical personnel. This study tested a novel multisensory alarm system which aims to help medical personnel better interpret and respond to alarm annunciation during periods of high cognitive load such as those found within intensive care units. We tested a multisensory alarm that combined auditory and vibrotactile cues to convey alarm type, alarm priority, and patient identity. Testing was done in three phases: control (conventional auditory), Half (limited multisensory alarm), and Full (complete multisensory alarm). Participants (N = 19, undergraduates) identified alarm type, priority, and patient identity (patient 1 or 2) using conventional and multisensory alarms, while simultaneously completing a cognitively demanding task. Performance was based on reaction time (RT) and identification accuracy of alarm type and priority. Participants also reported their perceived workload. RT was significantly faster for the Control phase (p < 0.05). Participant performance in identifying alarm type, priority, and patient did not differ significantly between the three phase conditions (p = 0.87, 0.37, and 0.14 respectively). The Half multisensory phase produced the lowest mental demand, temporal demand, and overall perceived workload score. These data suggest that implementation of a multisensory alarm with alarm and patient information may decrease perceived workload without significant changes in alarm identification performance. Additionally, a ceiling effect may exist for multisensory stimuli, with only part of an alarm benefitting from multisensory integration.

Intermittent-scanned continuous glucose monitoring with low glucose alarms decreases hypoglycemia incidence in middle-aged adults with type 1 diabetes in real-life setting

OBJECTIVE

There is limited real-life data demonstrating that hypo-/hyperglycemic alarms added to continuous glucose monitoring (CGM) improve metabolic control in adults with type 1 diabetes (T1D). We evaluated the usefulness of switching from a flash or intermittent-scanned continuous glucose monitoring (is-CGM) device without low or higher glucose alarms to a is-CGM device with alarms to prevent hypoglycemia in adults with T1D.

METHODS

Individuals with T1D and fearful of hypoglycemia, prone to hypoglycemia unawareness, and/or experiencing severe hypoglycemia while using is-CGM Free Style Libre 1 (FSL1) were switched to FSL2 with individually-programmable low glucose alarms. The primary endpoint was the changes in % time below range (TBR%) <70 mg/dl [3.9 mmol/l] and <54 mg/dl [3.0 mmol/l] after 12 weeks on FSL2 compared with FSL1. Secondary endpoints were changes in % time in range (TIR% 70-180 mg/dl [3.9-10.0 mmol/l]), % time above range (TAR%) >180 [10.0 mmol/l], mean interstitial glucose, glycemic management indicator (GMI), interstitial glucose coefficient of variation (CV%), hemoglobin A1c, and sensor's scans/day.

RESULTS

We included 108 individuals (57.4 % men), aged 58.2 ± 17.3 [95 % CI: 55.0 to 61.5] years, with mean diabetes duration 25 ± 14.6 [95 % CI: 22.1 to 27.7] years. Among individuals, 40 (37.0 %) had hypoglycemia awareness with Clarke's score ≥4 and 19 (17.5 %) had a history of severe hypoglycemia. The median low glucose alarm threshold was 70 [IQR: 65-70] mg/dl (3.9 [IQR: 3.6-3.9] mmol/L). By comparison of first 12 weeks on FSL2 vs. last 12 weeks on FSL1, TBR% <70 mg/dl decreased from 4.5 ± 4.4 to 2.3 ± 2.8 % (p < 0.001), TBR% <54 mg/dl decreased from 1.4 ± 2.2 to 0.3 ± 0.9 % (p < 0.001). TIR% was not significantly different (51.5 ± 14.9 vs. 52.9 ± 16 % (p = 0.13)), nor was TAR% (43.8 ± 16.2 vs. 44.7 ± 16.5 % (p = 0.5)). CV% decreased from 39.4 ± 6.9 to 37.9 ± 6.1 % (p < 0.001). Those at risk for hypoglycemia (TBR >4 % and >1 %, respectively, at baseline) showed a significant decrease in the incidence of hypoglycemia <70 and <54 mg/dl (p < 0.0001). Patients' satisfaction with hypoglycemia alarms was high, since all individuals opted to pursue using individual alarm beyond the study period.

CONCLUSION

Switching from FSL1 to FSL2 with low glucose alarms reduced the frequency of hypoglycemia in middle-age adults with T1D, particularly in those who were prone to hypoglycemia awareness or severe hypoglycemia.

A prospective and randomized study comparing the use of alarms, desmopressin and imipramine in the treatment of monosymptomatic nocturnal enuresis

BACKGROUND

Monosymptomatic enuresis (MNE) results from a pathogenic triad that may include lack of vasopressin secretion during sleep, reduced functional bladder capacity and inability to wake up during sleep. The treatment of MNE can be performed through behavioral therapy, use of alarms or medications such as desmopressin and imipramine.

OBJECTIVE

To compare the effectiveness of different treatments of MNE.

STUDY DESIGN

Prospective and randomized study comparing different intervention and a control group (receiving only behavior therapy) for MNE.

INCLUSION CRITERIA

age between 5 and 16 years old, with MNE, evaluated at the pediatric urology outpatient clinic of Hospital Infantil Menino Jesus. At first visit children were submitted to behavior therapy (urotherapy) for 3 months, children were subsequently characterized according to the ICCS as non-responders, partial responders, or full responders. Those partial responders or non-responders received a patient ID and were randomized to four groups: Alarm Group (G1), Desmopressin Group - DDAVP (G2), Imipramine Group (G3) and Control (G4). All groups were monitored monthly, for a period of 6 months. After 6 months, the children were reevaluated for MNE.

RESULTS

93 patients were enrolled. Mean age was 10.96 years with a standard deviation of 2.28 years, 59,1% were male. All groups had improvement in the number of dry nights (Table). Taking in account success the population full responders and partial responders: Alarm Group (G1) achieve success in 100% of cases, Desmopressin Group - DDAVP (G2) in 63.6% of cases, Imipramine Group (G3) in 73.7% of cases (Table 3). No drugs side effects were observed in both groups (G2 and G3), there was no dropout in patients who used alarms.

DISCUSSION

Our data suggests that the use of alarms is the most effective treatment of ENM with superior results when compared to imipramine and DDAVP. The small number of participants is a weakness of the study, as well as the lack of a voiding diary at the end of the study.

CONCLUSION

All therapeutics options utilized in the treatment of MNE are safe, effective and has a low rate of abandonment.

Extension of Tablo TrEatmeNt Duration (XTEND) study: successful 24 h prolonged therapy with Tablo in critical patients

Background

The Tablo® Hemodialysis System (Tablo) is an all in one, easy-to-learn device featuring integrated water purification, on demand dialysate production and two-way wireless data transmission and is approved for use in the acute, chronic, and home settings. Prior reports have demonstrated Tablo’s ability to achieve clinical goals, seamlessly integrate into hospitals and reduce cost across a wide range of treatment times. Extension of the Tablo cartridge to 24 h allows prolonged therapy and even greater flexibility for prescribers in the acute setting. The objective is to report on the first ever experience with Tablo prolonged therapy between 12 and 24 h in critically ill patients treated at a single-center ICU.

Methods

Nursing staff were trained during a single training session on Tablo prolonged therapy. After a run-in period of five treatments, Tablo data were collected via real-time transmission to a cloud-based, HIPAA compliant platform and reviewed by site staff. Dialysis treatment delivery, clinically significant alarms, and clotting events were recorded. Sub-group analysis between COVID-19 positive and negative patients were reported.

Results

One hundred (100) consecutive Tablo prolonged treatments had a median prescribed treatment time of 24 h and a median achieved treatment time of 21.3 h. Median cartridge usage was 1.3 per treatment. The dialysis treatment time was delivered in 91% of treatments, with 6% ending early due to an alarm, and 3% ending due to clotting.

Clinically significant alarms occurred at a median rate of 0.5 per treatment hour with a resolution time of 18 s. Median blood pump stoppage time related to these alarms was 2.3 min per treatment. Blood pump stoppage time was higher in the COVID-19 subgroup when compared to the non-COVID-19 subgroup.

Conclusion

Tablo successfully achieves prescribed treatment time with minimal therapy interruptions from alarms or cartridge changes. This data demonstrates the effectiveness of Tablo in achieving personalization of treatments necessary for unstable patients and enabling successful delivery of extended therapy with minimal clotting. Tablo’s prolonged therapy meets the needs of critically patients, including COVID-19 positive patients, requiring renal replacement therapy for greater than 12 h.

Key stakeholder perceptions of select forward mobile equipment pedestrian alarms

INTRODUCTION

Workplace interactions between pedestrians and industrial mobile equipment often result in workplace fatalities. Employers are normally required to provide pedestrian warning alarms for reverse travel only, though forward travel accidents may comprise as much as 50% of all related fatalities.

METHOD

This study was conducted to compare unique configurations of common pedestrian warning alarms to determine whether worker role or equipment configuration were significant independent variables of worker perception of forward alarm irritation and excellent warning characteristics, and whether forward alarms are perceived to be important.

RESULTS

While worker role was not found to be a significant variable, select alarm configuration properties were found to be significant. Practical Applications: The results of the study suggest that a combination of broadband and light emitting diode devices are preferential to all other configurations studied.

An inherently dangerous fluid warmer design

A Hotline® fluid warmer is a device commonly used by anesthesia providers in the operating room to warm and infuse blood products and large fluid volumes. The purpose of the fluid warmer is to counter heat loss, which occurs under anesthesia. Despite normal checks performed prior to its use, we discovered a breach in the fluid warming set attached to the Hotline® fluid warmer during blood administration. The breach contaminated the patient's sterile intravenous line. We describe the quality and safety processes we undertook in detail. We discuss the notion that monitoring alarms are an important safety feature of most modern devices utilized by anesthesia providers. We believe the Hotline® fluid warmer lacks a crucial monitor for detecting a breach within the fluid warming set, and therefore recommend the addition of an alarm to improve this device's safety.

A Practical Approach to Counseling Persons with Diabetes on Use of Optional CGM Alarms

Advances in glucose monitoring technologies have led to the development of different types of continuous glucose monitoring (CGM) platforms: traditional CGM and flash CGM. Both platforms provide critical glucose data that enable persons with diabetes (PwDs) to make more informed decisions in their self-management. Until recently, a key advantage of traditional CGM over flash CGM was the availability of automatic alarms that warn users about current or impending hypoglycemia and hyperglycemia. However, with the introduction of the FreeStyle Libre 2 (FSL2) system (Abbott Diabetes Care, Alameda, CA), PwD can now utilize flash CGM with the option to set low and high glycemic thresholds and receive alarms when these thresholds are crossed. In addition, having the option to use or not use the alarms may attract previous traditional CGM users who grew fatigued by constant alarms. However, despite the additional layer of safety that alarms provide, many PwD are reluctant to switch from self-monitoring of blood glucose to CGM due to concerns about how alarms could impact the quality of their daily lives. This reluctance is heightened by their perceptions that use of alarms is mandatory. Because the functionality of the FSL2 alarms differs from current traditional CGM devices, it is important that clinicians become familiar with these differences. Moreover, clinicians will be challenged to help PwD overcome their concerns about the use of alarms. This article presents a comprehensive description of the FSL2 alarms function and provides guidance to clinicians when counseling PwDs about the strengths, limitations, and various ways that the FSL2 alarms can be used in daily diabetes self-management.

Integrating Continuous Glucose Monitoring Into Clinical Practices and Patients' Lives

Numerous studies have demonstrated the clinical benefits of continuous glucose monitoring (CGM) in individuals with diabetes. Within ongoing innovations in CGM technology, individuals now have an expanding array of options that allow them to select the device that meets their individual needs and preferences. Although demand for CGM in primary care continues to grow, many clinicians are reluctant to prescribe this technology due to their unfamiliarity with the various devices, uncertainty about which devices are best suited to each patient and the feasibility of using CGM. This article reviews the features and functionality of the most recent commercially available CGM devices and provides guidance for integrating CGM use into clinical practices.

Contribution of alarm noise to average sound pressure levels in the ICU: An observational cross-sectional study

OBJECTIVES

To explore sound levels, alarm frequencies and the association between alarms and sound levels.

DESIGN

A single center observational cross-sectional study.

SETTING

Four intensive care units.

MAIN OUTCOME MEASURES

Contribution of alarms: red (life threatening), yellow (indicate excess of limits) and blue (technical) to sound pressure levels dB(A) at nursing stations.

RESULTS

Mean sound pressure levels differed significantly between day (56.1 ± 5.5), evening (55.1 ± 5.7) and night periods 53.6 ± 5.6; p < 0.01. 175,996 alarms were recorded of which 149,764 (85%) were yellow, 18,080 (10%) were red and 8,152 (5%) were blue. The mean sound levels without alarms (background) is 56.8 dB(A), with only red: 56.0 dB(A), only yellow: 55.6 dB(A), only blue: 56.0 dB(A) and mixed alarms: 56.3 dB(A). Yellow alarms (b = -0.93; 95% CI: -1.26 to -0.6; p < 0.001) were weakly but significantly associated with mean sound levels and lead to a slight decrease in noise level (1 dB), Red alarms (b = -0.3; 95% CI: -1.237 to 0.63; p = 0.52). The R Square of the model with all alarms was 0.01 (standard error of estimate, 6.9; p < 0.001).

CONCLUSIONS

Sound levels were high during all day-periods. Alarms exceeding limits occurred most frequently. However, the contribution of alarms to sound levels measured at the nursing station is clinically limited.

Preventing Falls in Hospitalized Patients: State of the Science

Falls in hospitalized patients are a pressing patient safety concern, but there is a limited body of evidence demonstrating the effectiveness of commonly used fall prevention interventions in hospitals. This article reviews common study designs and the evidence for various hospital fall prevention interventions. There is a need for more rigorous research on fall prevention in the hospital setting.

Real-World Hypoglycemia Avoidance with a Continuous Glucose Monitoring System's Predictive Low Glucose Alert

BACKGROUND

Programmable and fixed auditory and/or vibratory threshold alerts are essential features of real-time continuous glucose monitoring (rtCGM) systems that provide users time to intervene before the onset of clinical hypoglycemia or hyperglycemia. A sixth-generation rtCGM system from Dexcom, Inc. (G6) includes a new alert that is triggered when an algorithm predicts that an estimated glucose value ≤55 mg/dL will occur within 20 min, allowing users more time to act to avoid hypoglycemia. We examined whether this predictive low glucose alert provided added benefit to traditional low threshold alerts.

METHODS

We analyzed glucose values from an anonymized sample of 1424 patients who transitioned to G6 from the preceding fifth-generation system (G5) with no predictive alert. Users with the low threshold alert setting of 70 or 80 mg/dL were evaluated separately. Receiver users, those who disabled the predictive low glucose alert, or those with <30 days of data immediately before or after the transition to G6 were excluded.

RESULTS

Percent time <54, ≤55, <70, and >250 mg/dL fell significantly after the transition to G6, independent of low threshold alert setting. Time in range improved for G6 users with a low threshold alert setting of 70 mg/dL.

CONCLUSIONS

Advance warning provided by predictive low glucose alerts may further reduce hypoglycemia among rtCGM-experienced users.

What's all that noise-Improving the hospital soundscape

Hospital noise levels regularly exceed those recommended by the World Health Organization (WHO). It is uncertain whether high noise levels have adverse effects on patient health. High levels of noise increase patient sleep loss, anxiety levels, length of hospital stay, and morbidity rates. Staff conversation and auditory medical alarms are amongst the leading noise producing stimuli, with combinations of stimuli accounting for much of the high noise levels. The Hospital Consumer Assessment of Healthcare Providers and Systems survey shows a slight improvement in overall hospital noise levels in the United States, indicating a minor reduction in noise levels. Alarm ambiguity, alarm masking and inefficient alarm design contributes to a large portion of sounds that exceed the environmental noise level in the hospital. Improving the hospital soundscape can begin by training staff in noise reduction, enforcing noise reduction programs, reworking alarm design and encouraging research to evaluate the relative effects of noise producing stimuli on the hospital soundscape.

Perils of intraoperative neurophysiological monitoring: analysis of "false-negative" results in spine surgeries

BACKGROUND CONTEXT

Although some authors have published case reports describing false negatives in intraoperative neurophysiological monitoring (IONM), a systematic review of causes of false-negative IONM results is lacking.

PURPOSE

The objective of this study was to analyze false-negative IONM findings in spine surgery.

STUDY DESIGN

This is a retrospective cohort analysis.

PATIENT SAMPLE

A cohort of 109 patients with new postoperative neurologic deficits was analyzed for possible false-negative IONM reporting.

OUTCOME MEASURES

The causes of false-negative IONM reporting were determined.

MATERIALS AND METHODS

From a cohort of 62,038 monitored spine surgeries, 109 consecutive patients with new postoperative neurologic deficits were reviewed for IONM alarms.

RESULTS

Intraoperative neurophysiological monitoring alarms occurred in 87 of 109 surgeries. Nineteen patients with new postoperative neurologic deficits did not have an IONM alarm and surgeons were not warned. In addition, three patients had no interpretable IONM baseline data and no alarms were possible for the duration of the surgery. Therefore, 22 patients were included in the study. The absence of IONM alarms during these 22 surgeries had different origins: "true" false negatives where no waveform changes meeting the alarm criteria occurred despite the appropriate IONM (7); a postoperative development of a deficit (6); failure to monitor the pathway, which became injured (5); the absence of interpretable IONM baseline data which precluded any alarm (3); and technical IONM application issues (1).

CONCLUSIONS

Overall, the rate of IONM method failing to predict the patient's outcome was very low (0.04%, 22/62,038). Minimizing false negatives requires the application of a proper IONM technique with the limitations of each modality considered in their selection and interpretation. Multimodality IONM provides the most inclusive information, and although it might be impractical to monitor every neural structure that can be at risk, a thorough preoperative consideration of available IONM modalities is important. Delayed development of postoperative deficits cannot be predicted by IONM. Absent baseline IONM data should be treated as an alarm when inconsistent with the patient's preoperative neurologic status. Alarm criteria for IONM may need to be refined for specific procedures and deserves continued study.

Compliance with Washington State's requirement for residential carbon monoxide alarms

Carbon monoxide (CO) poisoning is responsible for significant morbidity and mortality in the US. In response, a majority of states have passed legislation in recent years requiring the installation of residential CO alarms. There is, however, no published information evaluating compliance with such laws. Employees of a Seattle medical center were surveyed in 2008 regarding home use of CO and smoke alarms. Washington State enacted legislation requiring residential CO alarms by all residences by January 1, 2013. The survey was repeated in mid-2016 to evaluate compliance. In 2016, a total of 354 employees completed the survey and their responses were compared to an equal number of 2008 survey respondents matched by home ownership and ZIP code. Residential CO alarm use rose from 37% to 78% (p < 0.0001). Among homeowners, 78% had alarms while 80% of renters had them. Homeowners with the highest compliance (96%) had purchased their homes since January 1, 2013 while those with the lowest compliance (73%) had purchased them earlier. A majority (79%) of renters without alarms reported the reason was that their landlord did not provide one, a violation of the law. Only one-half to two-thirds of all equipped homes had the required number of either CO or smoke alarms. Use of residential CO alarms increased significantly in this study population three years after law required them. Areas for further improvement include education of landlords, tenants, and longtime homeowners about the law, as well as public education regarding the number of CO and smoke alarms needed.

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Washington State has required residential carbon monoxide alarms since 2013.

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A survey on use of home CO alarms was conducted in 2008 and 2016.

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Residential CO alarm use increased from 41% to 78% overall.

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For the 20% of renters without alarms, most said their landlord didn't provide one.

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Use of home CO alarms increased significantly but further improvement is possible.

Reduction of clinically irrelevant alarms in patient monitoring by adaptive time delays

The problem of high rates of false alarms in patient monitoring in anesthesiology and intensive care medicine is well known but remains unsolved. False alarms desensitize the medical staff, leading to ignored true alarms and reduced quality of patient care. A database of intra-operative monitoring data was analyzed to find characteristic alarm patterns. The original data were re-evaluated to find relevant events and to rate the severity of these events. Based on this analysis an adaptive time delay was developed that individually delays the alarms depending on the grade of threshold deviation. The conventional threshold algorithm led to 4893 alarms. 3515 (71.84 %) of these alarms were annotated as clinically irrelevant. In total 81.0 % of all clinically irrelevant alarms were caused by only mild and/or brief threshold violations. We implemented the new algorithm for selected parameters. These parameters equipped with adaptive validation delays led to 1729 alarms. 931 (53.85 %) alarms were annotated as clinically irrelevant. 632 alarms indicated the 645 clinically relevant events. The positive predictive value of occurring alarms improved from 28.16 % (conventional algorithm) to 46.15 % (new algorithm). 13 events were missed. The false positive alarm reduction rate of the algorithm ranged from 33 to 86.75 %. The overall reduction was 73.51 %. The implementation of this algorithm may be able to suppress a large percentage of false alarms. The effect of this approach has not been demonstrated but shows promise for reducing alarm fatigue. Its safety needs to be proven in a prospective study.

An investigation of training strategies to improve alarm reactions

Researchers have suggested that operator training may improve operator reactions; however, researchers have not documented this for alarm reactions. The goal of this research was to train participants to react to alarms using sensor activity patterns. In Experiment 1, 80 undergraduates monitored a simulated security screen while completing a primary word search task. They received spatial, temporal, single sensor, or no training to respond to alarms of differing reliability levels. Analyses revealed more appropriate and quicker reactions when participants were trained and when the alarms were reliable. In Experiment 2, 56 participants practiced time estimation by simple repetition, performance feedback, or performance feedback and temporal subdivision. They then reacted to alarms based on elapsed time between sensor activity and alarm onset. Surprisingly, results indicated that participants did not benefit differentially from temporal interval training, focusing instead on advertised system reliability. Researchers should replicate these findings with realistic tasks and real-world complex task operators.

Learning three sets of alarms for the same medical functions: a perspective on the difficulty of learning alarms specified in an international standard

Three sets of eight alarms supporting eight functions specified in an international medical equipment standard (IEC 60601-1-8) were tested for learnability using non-anaesthetist participants. One set consisted of the tonal alarms specified in the standard. A second set consisted of a set of abstract alarms randomly selected from a database of abstract alarm sounds held by the authors. A third set of alarms was designed as indirect metaphors of the functions. Participants were presented with the alarms and then asked to identify them across ten blocks of eight trials. The results indicated a significant difference in learnability across the three sets of alarms. The indirect metaphors were learned significantly better than both other sets of alarms, and the randomly selected abstract alarms were learned significantly better than the alarms specified in the standard. The results suggest therefore that there are more readily learnable possible designs than those proposed in the standard. The use of auditory icons in particular should be given serious consideration as potential alarms for this application.

Arrhythmias in patients with acute coronary syndrome in the first 24 hours of hospitalization

OBJECTIVES

In patients with acute coronary syndrome (ACS), we sought to: 1) describe arrhythmias during hospitalization, 2) explore the association between arrhythmias and patient outcomes, and 3) explore predictors of the occurrence of arrhythmias.

METHODS

In a prospective sub-study of the IMMEDIATE AIM study, we analyzed electrocardiographic (ECG) data from 278 patients with ACS. On emergency department admission, a Holter recorder was attached for continuous 12-lead ECG monitoring.

RESULTS

Approximately 22% of patients had more than 50 premature ventricular contractions (PVCs) per hour. Non-sustained ventricular tachycardia (VT) occurred in 15% of patients. Very few patients (≤ 1%) had a malignant arrhythmia (sustained VT, asystole, torsade de pointes, or ventricular fibrillation). Only more than 50 PVCs/hour independently predicted an increased length of stay (p < .0001). No arrhythmias predicted mortality. Age greater than 65 years and a final diagnosis of acute myocardial infarction independently predicted more than 50 PVCs per hour (p = .0004).

CONCLUSIONS

Patients with ACS seem to have fewer serious arrhythmias today, which may have implications for the appropriate use of continuous ECG monitoring.