scholarly journals Current clinical methods of measurement of respiratory rate give imprecise values

2020 ◽  
Vol 6 (3) ◽  
pp. 00023-2020
Author(s):  
Gordon B. Drummond ◽  
Darius Fischer ◽  
D.K. Arvind

BackgroundRespiratory rate is a basic clinical measurement used for illness assessment. Errors in measuring respiratory rate are attributed to observer and equipment problems. Previous studies commonly report rate differences ranging from 2 to 6 breaths·min−1 between observers.MethodsTo study why repeated observations should vary so much, we conducted a virtual experiment, using continuous recordings of breathing from acutely ill patients. These records allowed each breathing cycle to be precisely timed. We made repeated random measures of respiratory rate using different sample durations of 30, 60 and 120 s. We express the variation in these repeated rate measurements for the different sample durations as the interquartile range of the values obtained for each subject. We predicted what values would be found if a single measure, taken from any patient, were repeated and inspected boundary values of 12, 20 or 25 breaths·min−1, used by the UK National Early Warning Score, for possible mis-scoring.ResultsWhen the sample duration was nominally 30 s, the mean interquartile range of repeated estimates was 3.4 breaths·min−1. For the 60 s samples, the mean interquartile range was 3 breaths·min−1, and for the 120 s samples it was 2.5 breaths·min−1. Thus, repeat clinical counts of respiratory rate often differ by >3 breaths·min−1. For 30 s samples, up to 40% of National Early Warning Scores could be misclassified.ConclusionsEarly warning scores will be unreliable when short sample durations are used to measure respiratory rate. Precision improves with longer sample duration, but this may be impractical unless better measurement methods are used.

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 962-963
Author(s):  
Daniel Stow ◽  
Robert Barker ◽  
Fiona Matthews ◽  
Barbara Hanratty

Abstract Tracking COVID-19 infections in the care home population has been challenging, because of the limited availability of testing and varied disease presentation. We consider whether National Early Warning Scores (NEWS/NEWS2) could contribute to COVID-19 surveillance in care homes. We analysed NEWS measurements from care homes in England (December 2019 to May 2020). We estimated pre-COVID (baseline) levels for NEWS and NEWS components using 80th and 20th centile scores for measurements before March 2020. We used time-series to compare the proportion of above-baseline NEWS to area-matched reports of registered deaths in care home residents from the Office for National Statistics We analysed 29,656 anonymised NEWS from 6,464 people in 480 care home units across 46 local authority areas. From March 23rd to May 20th, there were 5,753 deaths (1,532 involving COVID-19, 4,221 other causes) in corresponding geographical areas. A rise in the proportion of above-baseline NEWS was observed from March 16th 2020. The proportion of above-baseline oxygen saturation, respiratory rate and temperature measurements also increased approximately two weeks before peaks in deaths. We conclude that NEWS could contribute to disease surveillance in care homes during the COVID-19 pandemic. Oxygen saturation, respiratory rate and temperature could be prioritised as they appear to signal rise in mortality almost as well as total NEWS. This study reinforces the need to collate data from care homes, to monitor and protect residents’ health. Further work using individual level outcome data is needed to evaluate the role of NEWS in the early detection of resident illness.


2019 ◽  
Vol 6 (1) ◽  
pp. e000438 ◽  
Author(s):  
Frances S Grudzinska ◽  
Kerrie Aldridge ◽  
Sian Hughes ◽  
Peter Nightingale ◽  
Dhruv Parekh ◽  
...  

BackgroundCommunity-acquired pneumonia (CAP) is a leading cause of sepsis worldwide. Prompt identification of those at high risk of adverse outcomes improves survival by enabling early escalation of care. There are multiple severity assessment tools recommended for risk stratification; however, there is no consensus as to which tool should be used for those with CAP. We sought to assess whether pneumonia-specific, generic sepsis or early warning scores were most accurate at predicting adverse outcomes.MethodsWe performed a retrospective analysis of all cases of CAP admitted to a large, adult tertiary hospital in the UK between October 2014 and January 2016. All cases of CAP were eligible for inclusion and were reviewed by a senior respiratory physician to confirm the diagnosis. The association between the CURB65, Lac-CURB-65, quick Sequential (Sepsis-related) Organ Failure Assessment tool (qSOFA) score and National Early Warning Score (NEWS) at the time of admission and outcome measures including intensive care admission, length of hospital stay, in-hospital, 30-day, 90-day and 365-day all-cause mortality was assessed.Results1545 cases were included with 30-day mortality of 19%. Increasing score was significantly associated with increased risk of poor outcomes for all four tools. Overall accuracy assessed by receiver operating characteristic curve analysis was significantly greater for the CURB65 and Lac-CURB-65 scores than qSOFA. At admission, a CURB65 ≥2, Lac-CURB-65 ≥moderate, qSOFA ≥2 and NEWS ≥medium identified 85.0%, 96.4%, 40.3% and 79.0% of those who died within 30 days, respectively. A Lac-CURB-65 ≥moderate had the highest negative predictive value: 95.6%.ConclusionAll four scoring systems can stratify according to increasing risk in CAP; however, when a confident diagnosis of pneumonia can be made, these data support the use of pneumonia-specific tools rather than generic sepsis or early warning scores.


2018 ◽  
Vol 27 (3) ◽  
pp. 238-242
Author(s):  
Cheryl Gagne ◽  
Susan Fetzer

Background Unplanned admissions of patients to intensive care units from medical-surgical units often result from failure to recognize clinical deterioration. The early warning score is a clinical decision support tool for nurse surveillance but must be communicated to nurses and implemented appropriately. A communication process including collaboration with experienced intensive care unit nurses may reduce unplanned transfers. Objective To determine the impact of an early warning score communication bundle on medical-surgical transfers to the intensive care unit, rapid response team calls, and morbidity of patients upon intensive care unit transfer. Methods After an early warning score was electronically embedded into medical records, a communication bundle including notification of and telephone collaboration between medical-surgical and intensive care unit nurses was implemented. Data were collected 3 months before and 21 months after implementation. Results Rapid response team calls increased nonsignificantly during the study period (from 6.47 to 8.29 per 1000 patient-days). Rapid response team calls for patients with early warning scores greater than 4 declined (from 2.04 to 1.77 per 1000 patient-days). Intensive care unit admissions of patients after rapid response team calls significantly declined (P = .03), as did admissions of patients with early warning scores greater than 4 (P = .01), suggesting that earlier intervention for patient deterioration occurred. Documented reassessment response time declined significantly to 28 minutes (P = .002). Conclusion Electronic surveillance and collaboration with experienced intensive care unit nurses may improve care, control costs, and save lives. Critical care nurses have a role in coaching and guiding less experienced nurses.


2019 ◽  
pp. archdischild-2019-317055
Author(s):  
Marie Emilie Lampin ◽  
Alain Duhamel ◽  
Hélène Behal ◽  
Morgan Recher ◽  
Francis Leclerc ◽  
...  

ObjectivePaediatric early warning scores (EWS) were developed to detect deterioration in paediatric wards or emergency departments. The aim of this study was to assess the relationship between three paediatric EWS and clinical deterioration detected by the nurse in paediatric intermediate care units (PImCU).MethodsThis was a prospective, observational, multicentre study at seven French regional hospitals that included all children <18 years of age. Clinical parameters included in three EWS (Paediatric Advanced Warning Score, Paediatric Early Warning Score and Bedside Paediatric Early Warning System) were prospectively recorded every 8 hours or in case of deterioration. The outcome was a call to physician by the nurse when a clinical deterioration was observed. The cohort was divided into derivation and validation cohorts. An updated methodology for repeated measures was used and discrimination was estimated by the area under the receiver-operating curve.ResultsA total of 2636 children were included for 14 708 observations to compute a posteriori the EWS. The discrimination of the three EWS for predicting calls to physicians by nurses was good (range: 0.87–0.91) for the derivation cohort and moderate (range: 0.71–0.76) for the validation cohort. Equations for probability thresholds of calls to physicians, taking into account the time t, the score at time t and the score at admission, are available.ConclusionThese three EWS developed for children in paediatric wards or emergency departments can be used in PImCU to detect a clinical deterioration and predict the need for medical intervention.


2014 ◽  
Vol 13 (2) ◽  
pp. 56-60
Author(s):  
C J Yiu ◽  
◽  
S U Khan ◽  
Christian P Subbe ◽  
K Tofeec ◽  
...  

Background: Early Warning Scores alert staff to preventable deterioration. Raised scores should lead to escalation of care. Aims: To establish response of staff to patients scoring National Early Warning Score (NEWS) of six or above and to identify patient and environmental factors affecting escalation by nursing staff. Methods: Service evaluation with prospective review of patient records of 118 beds on four medical wards during 20 night-shifts. Results: During 2360 observed bed days 109 patients triggered NEWS >=6 at least once during the observation period. Nursing staff escalated only 18 (17%) of these patients; nearly all of them had predefined chronic health conditions, the majority fulfilled criteria for frailty. Despite their higher 30-day mortality patients with COPD had lower escalation rates. Additionally wards that had more patients with a NEWS >=6 had lower escalation rates. Conclusion: Alarm fatigue and clinical judgement of staff might result in deviation from escalation protocols.


JAMIA Open ◽  
2021 ◽  
Vol 4 (3) ◽  
Author(s):  
Sean C Yu ◽  
Nirmala Shivakumar ◽  
Kevin Betthauser ◽  
Aditi Gupta ◽  
Albert M Lai ◽  
...  

Abstract The objective of this study was to directly compare the ability of commonly used early warning scores (EWS) for early identification and prediction of sepsis in the general ward setting. For general ward patients at a large, academic medical center between early-2012 and mid-2018, common EWS and patient acuity scoring systems were calculated from electronic health records (EHR) data for patients that both met and did not meet Sepsis-3 criteria. For identification of sepsis at index time, National Early Warning Score 2 (NEWS 2) had the highest performance (area under the receiver operating characteristic curve: 0.803 [95% confidence interval [CI]: 0.795–0.811], area under the precision recall curves: 0.130 [95% CI: 0.121–0.140]) followed NEWS, Modified Early Warning Score, and quick Sequential Organ Failure Assessment (qSOFA). Using validated thresholds, NEWS 2 also had the highest recall (0.758 [95% CI: 0.736–0.778]) but qSOFA had the highest specificity (0.950 [95% CI: 0.948–0.952]), positive predictive value (0.184 [95% CI: 0.169–0.198]), and F1 score (0.236 [95% CI: 0.220–0.253]). While NEWS 2 outperformed all other compared EWS and patient acuity scores, due to the low prevalence of sepsis, all scoring systems were prone to false positives (low positive predictive value without drastic sacrifices in sensitivity), thus leaving room for more computationally advanced approaches.


Author(s):  
Ewan Carr ◽  
Rebecca Bendayan ◽  
Daniel Bean ◽  
Matt Stammers ◽  
Wenjuan Wang ◽  
...  

AbstractObjectivesTo evaluate the National Early Warning Score (NEWS2), currently recommended in the UK for risk-stratification of severe COVID-19 outcomes, and subsequently identify and validate a minimal set of common parameters taken at hospital admission that improve the score.DesignRetrospective observational cohort with internal and multi-hospital external validation.SettingSecondary care.InterventionsNot applicable.ParticipantsMain outcome measuresResultsTraining and temporal external validation cohorts comprised 1464 patients admitted to King’s College Hospital NHS Foundation Trust (KCH) with COVID-19 disease from 1st March to 30th April 2020. External validation cohorts included 3869 patients from two UK NHS Trusts (Guys and St Thomas’ Hospitals, GSTT and University Hospitals Southampton, UHS) and two hospitals in Wuhan, China (Wuhan Sixth Hospital and Taikang Tongji Hospital).The primary outcome was patient status at 14 days after symptom onset categorised as severe disease (transferred to intensive care unit or death). Age, physiological measures, blood biomarkers, sex, ethnicity and comorbidities (hypertension, diabetes, cardiovascular, respiratory and kidney diseases) were included.ConclusionsNEWS2 score on admission was a weak predictor of severe COVID-19 infection (AUC = 0.628). Adding age and common blood tests (CRP, neutrophil count, estimated GFR and albumin) provided substantial improvements to a risk stratification model, particularly in relation to sensitivity, but performance was only moderate (AUC = 0.753). Improvement over NEWS2 remained robust and generalisable in GSTT (AUC = 0.817), UHS (AUC = 0.835) and Wuhan hospitals (AUC = 0.918).Adding age and a minimal set of blood parameters to NEWS2 improves the detection of patients likely to develop severe COVID-19 outcomes. This finding was replicated across NHS and non-UK hospitals. Adding a few common parameters to a pre-existing acuity score allows rapid and easy implementation of this risk-scoring system.Key MessagesThe National Early Warning Score (NEWS2), currently recommended for severe COVID-19 disease in the UK shows overall poor discrimination for severe outcomes (transfer to ICU or death). It can be improved by the addition of a small number of blood and physiological parameters routinely measured at hospital admission.The addition of age and a minimal set of common blood tests (C-reactive protein, neutrophil count, estimated GFR and albumin) provided substantial improvements in a risk stratification model.Although predictive performance varied from hospital to hospital, the improvement over NEWS2 alone was consistent across different patient cohorts.The proposed addition of a limited number of dichotomised parameters is easily derived from a pre-existing acuity score would be substantially easier to implement in a short-time scale compared to novel high-dimensional risk-scoring systems.


CJEM ◽  
2017 ◽  
Vol 20 (2) ◽  
pp. 266-274 ◽  
Author(s):  
Steven Skitch ◽  
Benjamin Tam ◽  
Michael Xu ◽  
Laura McInnis ◽  
Anthony Vu ◽  
...  

ABSTRACTObjectivesEarly warning scores use vital signs to identify patients at risk of critical illness. The current study examines the Hamilton Early Warning Score (HEWS) at emergency department (ED) triage among patients who experienced a critical event during their hospitalization. HEWS was also evaluated as a predictor of sepsis.MethodsThe study population included admissions to two hospitals over a 6-month period. Cases experienced a critical event defined by unplanned intensive care unit admission, cardiopulmonary resuscitation, or death. Controls were randomly selected from the database in a 2-to-1 ratio to match cases on the burden of comorbid illness. Receiver operating characteristic (ROC) curves were used to evaluate HEWS as a predictor of the likelihood of critical deterioration and sepsis.ResultsThe sample included 845 patients, of whom 270 experienced a critical event; 89 patients were excluded because of missing vitals. An ROC analysis indicated that HEWS at ED triage had poor discriminative ability for predicting the likelihood of experiencing a critical event 0.62 (95% CI 0.58-0.66). HEWS had a fair discriminative ability for meeting criteria for sepsis 0.77 (95% CI 0.72-0.82) and good discriminative ability for predicting the occurrence of a critical event among septic patients 0.82 (95% CI 0.75-0.90).ConclusionThis study indicates that HEWS at ED triage has limited utility for identifying patients at risk of experiencing a critical event. However, HEWS may allow earlier identification of septic patients. Prospective studies are needed to further delineate the utility of the HEWS to identify septic patients in the ED.


Resuscitation ◽  
2005 ◽  
Vol 65 (1) ◽  
pp. 41-44 ◽  
Author(s):  
Jackie McBride ◽  
Debbie Knight ◽  
Jo Piper ◽  
Gary B Smith

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