Heart Rate Alarms Research Articles

BARRIERS to Early Detection of Deterioration in Hospitalized Infants Using Predictive Analytics.

BARRIERS to Early Detection of Deterioration in Hospitalized Infants Using Predictive Analytics.

Reducing Insignificant High/Low Heart Rate Alarms Using the Cross-Limit Area Based Algorithm

Significant ST-segment changes raise concern for myocardial ischemia, cardiomyopathy or myocardial inflammation and therefore, warrant an extensive and often invasive cardiovascular evaluation. We report a 12 year-old asymptomatic African-American girl with marked ST-segment elevation in leads I and aVL and ST-segment depression in inferior leads II, III and aVF. Extensive cardiovascular evaluation did not reveal any abnormality suggesting that these findings, which have previously not been reported, are likely benign, at least in this young girl.

Abstract 190: A Systematic Alarm Management Pilot to Reduce Alarm Fatigue at a Tertiary Care Center

Background: While alarms on hospital telemetry units are vital to patient safety, alarm fatigue is a well-established and potentially dangerous consequence. Our goal was to implement an alarm management pilot to systematically determine how to safely reduce alarm burden. Methods: The Brigham and Women’s Hospital Monitoring Steering Committee (BWH MSC) studied the effect of alarm fatigue from March to November 2014 in a multiweek, phased pilot (Figure 1). The intervention groups were two medical/surgical stepdown units (group 1) and three cardiac stepdown units (group 2). The control group was a combination of two medical/surgical units and one cardiac stepdown unit. Various interventions were performed in a stepwise and cumulative manner. Electrodes were switched on a daily basis. The high heart rate (HR) alarm threshold was increased from 120 to 130 beats per minute (bpm) and the low HR threshold was decreased from 50 to 45 bpm. Duplicate alarms (e.g. “tachy” alarm same as high HR parameter alarm) and non-actionable alarms (e.g. “couplets”) were switched to messages (non-audible). Alarm data was pulled and analyzed on a weekly basis. Results: At baseline, there was wide fluctuation in alarms monitored/week across all three groups; however, the peak alarm unit averaged roughly 400 audible, unique alarms/bed/day. Heart rate alarms decreased by 54% after phase 2 in group 1 and 48% after phase 2 in group 2 (Figure 1). Audible alarms were reduced in phase 3 and 4, most notably by making non-actionable alarms inaudible (34% decrease in phase 3 in group 1, 64% decrease in phase 4 in group 2). Electrode alarms appeared to be mildly reduced in phase 1 and 2 (4-24%), however, these findings were not consistent in phase 3 and 4. Conclusions: Alarm type and burden varied widely across time and hospital units, making it difficult to generalize interventions. However, based on the pilot results, the BWH MSC implemented the following changes across all telemetry units: 1) high HR limit and low HR limits were made more permissive as above, and 2) duplicate and non-actionable alarms were made non-audible. The latter intervention was thought to provide the greatest impact based on our experience. While this pilot represented a systematic approach to reduce alarm burden, ongoing efforts to safely improve alarm burden are warranted.

Responses to Fetal Heart Rate Alarms on a Busy Tertiary Labor and Delivery Unit [12R

INTRODUCTION: Alarm fatigue is a well-recognized phenomenon that has been demonstrated to impede rather than promote patient safety. This study investigates the incidence of electronic fetal heart rate (FHR) monitor alarms and staff responses. METHODS: The FHR monitor database from the labor and delivery (L&D) unit was queried to determine the number and duration of alarms/day over the course of 7 consecutive days. In addition, a survey was sent to L&D care providers to determine their subjective impression of how often the alarms were activated and their action if any. RESULTS: Over 7 consecutive days, there were 130 deliveries associated with 4981 alarm events with a cumulative total of 103 hours of alarms (average 15 alerts/hr totaling cumulative average 7.4 hrs/day). Surveys were sent to 322 staff with responses from 159 (49%). Thirty-four (21.4%) surveys were incomplete. Of respondents 69% (110) had the subjective impression that the alarms were ringing either “often” or “almost all the time.” Of those only 59% took some action while 41% ignored or hardly noticed the alarms. CONCLUSION: In this study of a high-volume academic hospital L&D unit, our data show that FHR monitor alarms are ringing every 4 minutes for a cumulative total of about 1/3 of the day. However, these alerts are ignored by almost half of the staff. Consequently, we believe that either the use of FHR monitor alarms or the policies and procedure regarding those alarms should be reviewed to ensure that their use is having a positive impact on patient safety.

Understanding heart rate alarm adjustment in the intensive care units through an analytical approach

BackgroundHeart rate (HR) alarms are prevalent in ICU, and these parameters are configurable. Not much is known about nursing behavior associated with tailoring HR alarm parameters to individual patients to reduce clinical alarm fatigue.ObjectivesTo understand the relationship between heart rate (HR) alarms and adjustments to reduce unnecessary heart rate alarms.MethodsRetrospective, quantitative analysis of an adjudicated database using analytical approaches to understand behaviors surrounding parameter HR alarm adjustments. Patients were sampled from five adult ICUs (77 beds) over one month at a quaternary care university medical center. A total of 337 of 461 ICU patients had HR alarms with 53.7% male, mean age 60.3 years, and 39% non-Caucasian. Default HR alarm parameters were 50 and 130 beats per minute (bpm). The occurrence of each alarm, vital signs, and physiologic waveforms was stored in a relational database (SQL server).ResultsThere were 23,624 HR alarms for analysis, with 65.4% exceeding the upper heart rate limit. Only 51% of patients with HR alarms had parameters adjusted, with a median upper limit change of +5 bpm and -1 bpm lower limit. The median time to first HR parameter adjustment was 17.9 hours, without reduction in alarms occurrence (p = 0.57).ConclusionsHR alarms are prevalent in ICU, and half of HR alarm settings remain at default. There is a long delay between HR alarms and parameters changes, with insufficient changes to decrease HR alarms. Increasing frequency of HR alarms shortens the time to first adjustment. Best practice guidelines for HR alarm limits are needed to reduce alarm fatigue and improve monitoring precision.

Inpatient-Derived Vital Sign Parameters Implementation: An Initiative to Decrease Alarm Burden.

To implement data-driven vital sign parameters to reduce bedside monitor alarm burden. Single-center, quality-improvement initiative with historical controls assessing the impact of age-based, inpatient-derived heart rate (HR) and respiratory rate (RR) parameters on a 20-bed acute care ward that serves primarily pediatric cardiology patients. The primary outcome was the number of alarms per monitored bed day (MBD) with the aim to decrease the alarms per MBD. Balancing measures included the frequency of missed rapid response team activations, acute respiratory code events, and cardiorespiratory arrest events in the unit with the new vital sign parameters. The median number of all cardiorespiratory monitor alarms per MBD decreased by 21% from 52 (baseline period) to 41 (postintervention period) (P < .001). This included a 17% decrease in the median HR alarms (9-7.5 per MBD) and a 53% drop in RR alarms (16.8-8.0 per MBD). There were 57 rapid response team activations, 8 acute respiratory code events, and no cardiorespiratory arrest events after the implementation of the new parameters. An evaluation of HRs and RRs recorded at the time of the event revealed that all patients with HRs and/or RRs out of range per former default parameters would also be out of range with the new parameters. Implementation of data-driven HR and iteratively derived RR parameters safely decreased the total alarm frequency by 21% in a pediatric acute care unit.

Under-recognition of alarms in a neonatal intensive care unit

BackgroundTreatment decisions for apnoea of prematurity (AOP) are usually based on nursing staff's documentation of pulse oximeter and heart rate alarms.ObjectiveIn an observational study, to compare the accuracy of oxygen...

What Are We Missing? Arrhythmia Detection in the Pediatric Intensive Care Unit

To test the hypothesis that instituting a process of routine daily review of rhythm alarms in non-cardiac patients in the pediatric intensive care unit would yield clinically important disturbances that would otherwise go undetected. A prospective observational study was performed over a consecutive 28-day period. Total bedside monitor alarms, rhythm alarms, and heart rate (HR) trends were recorded. Rhythm alarm recordings were reviewed independently by two study team members. Medical records for patients with critical arrhythmias were reviewed to evaluate for prior knowledge of the event and to correlate with clinical data. We evaluated 86 patients (343 patient-days). There were 54,656 total monitor alarms (159.3 alarms/patient-day), of which 19,970 (37%) were rhythm alarms, including 4032 (20%) critical arrhythmias. Fifty-six percent of the critical alarms were artifactual. Seventeen of the 1786 ventricular tachycardia alarms represented true episodes that occurred in 5 patients. Two patients' care were altered as a result of detection of the arrhythmia in the review process. Eight hundred sixty-five (98%) of the 883 true critical alarms reviewed were for extreme HR. Eighty-three percent (5172) of the 6239 true non-critical alarms reviewed were HR alarms. Daily review of rhythm alarms improves detection of clinically relevant arrhythmias in non-cardiac pediatric intensive care unit patients.

Setting up a heart rate alarm limit to decrease oculocardiac reflex during strabismus surgery in children

The aim of this paper is to investigate a method which may decrease the incidence and severity of oculocardiac reflex (OCR) without drugs. One hundred and sixty children undergoing strabismus surgery were allocated to two groups using double-blind randomization. OCR was defined as a decrease of more than 10% from the baseline heart rate during operation. An alarm sounded and a lamp flashed as soon as OCR occurred in group I, and neither of the above happened in group II. OCR occurred (1.151 ± 0.858) times in group I and (2.287 ± 1.371) times in group II (P < 0.05). Heart rate decreased by (23 ± 19) bpm in group I and (35 ± 28) bpm in group II (P < 0.05). The duration of OCR in group I and group II was (4.36 ± 4.26)s and (7.62 ± 6.41)s, respectively (P < 0.05). The recovery time for group I and group II was (15.36 ± 13.28)s and (32.36 ± 19.57)s, respectively (P < 0.05). The numbers of times of interruption were 8 in group I (10%) and 26 in group II (32%) (P < 0.01). This method significantly decreased the incidence and severity of OCR during strabismus surgery in children.

Theatre monitor alarm settings: a pilot survey in Scotland and Belgium.

The use of alarms on operating theatre equipment was explored in a questionnaire to anaesthetists in Belgium and Scotland. They were presented with a scenario of a fit male having an anaesthetic for an abdominal operation. The overall response rate was 72%, giving 100 records for analysis. The responses from Scottish and Belgian anaesthetists were similar except for views on setting an upper limit for systolic arterial pressure; Scottish anaesthetists seemed relatively unwilling to set an upper systolic arterial pressure limit. Beyond this, the respondents considered alarms to be a method of detecting problems before they occur and they readjust alarms for each patient. They would set systolic arterial pressure alarms 30 mmHg above and below the patients normal pressure, the heart rate alarms 30 bpm above and 20 bpm below the actual rate, and the peripheral oxygen saturation lower alarm limit to 90%.

Robust sensor fusion improves heart rate estimation: clinical evaluation.

To determine if Robust Sensor Fusion (RSF), a method designed to fuse data from multiple sensors with redundant heart rate information can be used to improve the quality of heart rate data. To determine if the improved estimate of heart rate can reduce the number of false and missed heart rate alarms. A total of 85 monitoring periods were investigated, 12 from the operating room, 60 from adult ICU and 13 from pediatric ICU. The operating room periods began with induction of anesthesia and ended at the completion of the anesthetic. For the ICU data, four hour blocks of time were studied. For each monitoring period, HR values were recorded at 5 second intervals or less from the ECG, SpO2 and IAC using a SpaceLabs Medical Gateway connected to a SpaceLabs Medical PC2. Fused estimates of HR were derived for every time point using RSF and all results accepted regardless of confidence value. Data were annotated manually to identify the "reference" HR (that HR value most likely to be correct) at all time points. All HR values from the sensors and the fused estimate that were different from the reference HR by more than +/- 5 beats/min were considered inaccurate. For each monitoring period, the total time per hour that data were either inaccurate or unavailable was calculated for each sensor as well as the fused estimates. The total time of false and missed HR alarms was found for all sensors and the fused estimate by comparing the data to thresholds for both high and low HR alarms at 150 bpm, 130 bpm, 110 bpm and 50 bpm, 40 bpm, 30 bpm respectively. The fused estimate of HR was consistently as good or better than the estimate available from any individual sensor. The fused estimates also consistently reduced the incidence of false alarms compared with individual sensors without an unacceptable incidence of missed alarms. Redundancy in sensor measurements can be used to improve HR estimation in the clinical setting. Methods like RSF which improve the quality of monitored data and reduce nuisance alarms will enhance the value of patient monitors to clinicians.

Parental Reports of Apnea and Bradycardia: Temporal Characteristics and Accuracy

A prospective examination was made of the temporal course of parental observations in response to a monitor alarm of apnea (apnea setting of 20 seconds) or bradycardia (bradycardia setting of 80 beats per minute). Data were obtained from 155 subsequent sudden infant death syndrome siblings followed up at home, during the first 20 weeks of life, on an apnea/bradycardia monitor with an attached event recorder. In addition, parental reports were compared to an objective recording of the pattern of cardiorespiratory activity surrounding each monitor alarm. Only those parental observations were considered which reported the infant to be asleep with no apparent equipment malfunction following an apnea alarm (with or without pallor, cyanosis, or the provision of external stimulation) or a low heart rate alarm associated with pallor, cyanosis, or stimulation. Observations were analyzed within each of five age periods (less than 29, 29 through 56, 57 through 84, 85 through 112, 113 through 140 days). The percentage of infants reported to have prolonged apnea, prolonged apnea with stimulation, or bradycardia with stimulation was found to decrease with age. An examination of the linked event recordings failed to document an episode of apnea as long as 15 seconds for any of the reported episodes of apnea. Furthermore, bradycardia as long as 5 seconds in duration could be documented in only 3 of 422 reported episodes of bradycardia. These results indicate the potential for considerable error when total reliance is placed on parental observations and point to the necessity for objective event recordings when using home monitors in the clinical management of at-risk infants.

Frequency and reliability of alarms in the monitoring of cardiac postoperative patients

Postoperative monitoring of cardiac operated patients requires appropriately functioning monitor alarms as well as intensive nursing activity. The limit alarms can be used for detection of life-threatening situations and monitoring of physiological changes in the patient's state. We studied the significance and the frequency of audible alarms during the postoperative intensive care of ten cardiac patients. Of 1307 occasions when such an alarm was activated during the study period of approximately 26 hours per patient, only 139 (10.6%) were significant. The highest proportion of significant audible limit alarms was found during the immediate postoperative period. Heart rate alarms were more reliable than alarms of the other parameters monitored in the study. Possibilities for improving the physiological monitoring and alarm system are discussed.

FAILURE OF CONVENTIONAL RESPIRATORY MONITORING TO DETECT HYPOXIA

We studied 21 preterm infants (550-1870 gms and 27-34 wks gestation) who had recurrent apnea. For 145 hrs in perionds of 2-7 hrs we continuously monitored transcutaneous oxygen tension (tcPO2) relative blood flow, heart rate and thoracic impedance. Nasal air flow was monitored with a thermistor on 8 occasions. We recorded tcPO2 during 544 periods of apnea ≥ 15 sec.. The tcPO2 fell to below 40 torr during 178 apneic periods. Only 64 of three episodes activated the apnea alarm (set to respond after 15 secs. of apnea). The heart rate alarm (set to alarm at 100 beat/min) was activated in only 108/178 (Fig. 1). We conclude that conventional methods of respiratory monitoring are poor detectors of hypoxia due to apnea.

Evaluation of a computerized arrhythmia alarm system

A prospective study of a computerized arrhythmia alarm system was carried out in the coronary care unit during 200 patient hours of monitoring. The computer system was designed to activate an alarm on the development of rhythm and conduction disorders including asystole, ventricular tachycardia, atrial tachycardia, sinus tachtcardia, bradycardia, frequent premature ventricular beats, atrial fibrillation and bundle branch block. Study patients were simultaneously monitored by the computer system and a conventional analog heart rate alarm system. All alarms generated by the two systems were evaluated. Of 79 computer alarms, 42 (53 percent) were true positive alarms; during the same period there were 167 analog alarms of which only 13 (8 percent) were true positive alarms. In both systems, false positive alarms were primarily due to patient movement, but they occurred only 25 percent as often with the computer system as with the analog system. These results indicate that computerized arrhythmia monitoring systems offer significant advantages over conventional monitoring techniques.