Remote vision-based digital patient monitoring of pulse and respiratory rates in acute medical wards.

Remote Vision-Based digital Patient Monitoring (VBPM) of pulse (PR) and respiratory rate (RR) was set up in six single rooms in an acute medical and an orthopaedic ward. We compared 102 PR and 154 RR VBPM measurements (from 27 patients) with paired routine nurse measurements. VBPM measurements of RR were validated by reviewing video footage. Nurse measurements of RR were often 16-18 breaths/minute, and did not match VBPM RR (overestimating at low RR and underestimating at high RR). Nurse measurements of pulse were on average 3.9 beats per minute greater than matched VBPM measurements. VBPM was unobtrusive and well accepted.

Increased seizure frequency in an epilepsy patient receiving medium cut-off dialysis.

This paper presents the case of a male dialysis patient, with generalised epilepsy, who experienced complications after starting medium cut-off (MCO) dialysis. While receiving haemodiafiltration, the patient's epilepsy had been relatively well controlled using two antiseizure medications (brivaracetam and sodium valproate). However, the patient's seizure frequency increased when he was changed to MCO dialysis. MCO is a new dialysis method that has been developed to allow for better clearance of uraemic toxins through its larger pore size. We hypothesise that using the highly permeable MCO membrane changed the seizure threshold by an unknown mechanism. This is the first reported case to observe increased seizure frequency in a patient receiving MCO dialysis. The case highlights the need for caution when prescribing dialysis methods to patients with epilepsy.

Impact of a standardised rapid response system on clinical outcomes of female patients: an interrupted time series approach.

BACKGROUND: This study aimed to assess the impact of a standardised rapid response systems (the Between the Flags (BTF)) implemented across New South Wales (NSW), Australia, among female patients. METHODS: We conducted an interrupted time series (2007-2013) population-based linkage study including 5 114 170 female patient (≥18 years old) admissions in all 232 public hospitals in NSW. We studied changes in levels and trends of patient outcomes after BTF implementation among four age groups of female patients. RESULTS: Before the BTF system introduction (2007-2009), for the female patients as a whole, there was a progressive decrease in rates of in-hospital cardiopulmonary arrest (IHCA), IHCA-related mortality and hospital mortality for female patients. However, there were no changes in deaths in low-mortality diagnostic-related groups (DLMDRGs), IHCA survival to discharge and 1-year post-discharge mortality after surviving an IHCA. Only the female patients aged 55 years and older showed the same results as the whole sample. After the BTF programme (2010-2013), the same trends (except for DLMDRG) continued for female patients as a whole and for those aged 55 years or older. There was a significant reduction in DLMDRG among female patients aged 35-54 years (p<0.001), those aged 75 years and over (p<0.05) and female patients as a whole (p<0.05). The decreasing secular trend of surviving an IHCA to hospital discharge before the BTF system (p<0.05) among patients aged 18-34 years old was reversed after the BTF implementation (p<0.01). CONCLUSIONS: For female patients the BTF programme introduction was associated with continued reductions in the rates of IHCA, IHCA-related mortality and hospital mortality, as well as a new reduction in DLMDRG for 35-54 years old patients and those aged 75 years and older, and increased survival for those aged 18-34 years who had suffered an IHCA.

Computerized Clinical Decision Support Systems for the Early Detection of Sepsis Among Adult Inpatients: Scoping Review.

BACKGROUND: Sepsis is a significant cause of morbidity and mortality worldwide. Early detection of sepsis followed promptly by treatment initiation improves patient outcomes and saves lives. Hospitals are increasingly using computerized clinical decision support (CCDS) systems for the rapid identification of adult patients with sepsis. OBJECTIVE: This scoping review aims to systematically describe studies reporting on the use and evaluation of CCDS systems for the early detection of adult inpatients with sepsis. METHODS: The protocol for this scoping review was previously published. A total of 10 electronic databases (MEDLINE, Embase, CINAHL, the Cochrane database, LILACS [Latin American and Caribbean Health Sciences Literature], Scopus, Web of Science, OpenGrey, ClinicalTrials.gov, and PQDT [ProQuest Dissertations and Theses]) were comprehensively searched using terms for sepsis, CCDS, and detection to identify relevant studies. Title, abstract, and full-text screening were performed by 2 independent reviewers using predefined eligibility criteria. Data charting was performed by 1 reviewer with a second reviewer checking a random sample of studies. Any disagreements were discussed with input from a third reviewer. In this review, we present the results for adult inpatients, including studies that do not specify patient age. RESULTS: A search of the electronic databases retrieved 12,139 studies following duplicate removal. We identified 124 studies for inclusion after title, abstract, full-text screening, and hand searching were complete. Nearly all studies (121/124, 97.6%) were published after 2009. Half of the studies were journal articles (65/124, 52.4%), and the remainder were conference abstracts (54/124, 43.5%) and theses (5/124, 4%). Most studies used a single cohort (54/124, 43.5%) or before-after (42/124, 33.9%) approach. Across all 124 included studies, patient outcomes were the most frequently reported outcomes (107/124, 86.3%), followed by sepsis treatment and management (75/124, 60.5%), CCDS usability (14/124, 11.3%), and cost outcomes (9/124, 7.3%). For sepsis identification, the systemic inflammatory response syndrome criteria were the most commonly used, alone (50/124, 40.3%), combined with organ dysfunction (28/124, 22.6%), or combined with other criteria (23/124, 18.5%). Over half of the CCDS systems (68/124, 54.8%) were implemented alongside other sepsis-related interventions. CONCLUSIONS: The current body of literature investigating the implementation of CCDS systems for the early detection of adult inpatients with sepsis is extremely diverse. There is substantial variability in study design, CCDS criteria and characteristics, and outcomes measured across the identified literature. Future research on CCDS system usability, cost, and impact on sepsis morbidity is needed. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): RR2-10.2196/24899.

Rare yet catastrophic presentation of undiagnosed antiphospholipid syndrome.

A previously well 31-year-old woman initially presented to the emergency department with pneumonia, however, was found to be hypertensive and have new-onset cardiomegaly. She was admitted for intravenous antibiotics and concurrently a series of investigations were conducted to investigate hypertension and cardiomegaly. During the course of admission, she developed acute kidney injury and was found to have acute chronic occlusion in the abdominal aorta. She was diagnosed with catastrophic antiphospholipid syndrome. This is a rare form of antiphospholipid syndrome with a high mortality rate. Thus, it is important that clinicians are aware of this syndrome to facilitate early diagnosis and initiation of treatment.

Severe psittacosis progressing to suspected organizing pneumonia and the role of corticosteroids.

BACKGROUND: Psittacosis is a systemic disease usually with respiratory involvement, caused by the obligate intracellular bacterium Chlamydia psittaci. Exposure to birds, the main zoonotic reservoir, is a major risk factor for infection. The spectrum of disease is highly variable, ranging from subclinical infection to severe pneumonia requiring mechanical ventilation. There is limited data on psittacosis progressing to organizing pneumonia and management of such cases. CASE PRESENTATION: A 63-year-old man was referred to a rural hospital with 11 days of fevers to 39 °C, myalgia, lethargy and several days of dry cough. After initial treatment with benzylpenicillin and doxycycline for left lower pneumonia found on CXR, the patient deteriorated with extensive bilateral consolidation on chest CT requiring mechanical ventilation. Atypical pneumonia screening was negative, however, exposure to a sick bird prior to symptom onset triggered testing for C. psittaci which was positive. Doxycycline was recommenced with minimal benefit, and organizing pneumonia was later suspected. The patient slowly improved with a weaning course of corticosteroids started after 19 days and was discharged from hospital. He unfortunately was re-admitted and died several months later. CONCLUSION: Severe pneumonia is a rare, but potentially life-threatening complication of psittacosis. We present a case of psittacosis which progressed to suspected organizing pneumonia despite appropriate antibiotics, and subsequent treatment with corticosteroids. This case suggests it may be useful to consider corticosteroids early in therapy for patients with severe psittacosis. Our paper underlines the need for further research to determine the best management of severe psittacosis to improve patient outcomes.

Evaluation of an augmented emergency department electronic medical record-based sepsis alert.

OBJECTIVE: Electronic medical records-based alerts have shown mixed results in identifying ED sepsis. Augmenting clinical patient-flagging with automated alert systems may improve sepsis screening. We evaluate the performance of a hybrid alert to identify patients in ED with sepsis or in-hospital secondary outcomes from infection. METHODS: We extracted a dataset of all patients with sepsis during the study period at five participating Western Sydney EDs. We evaluated the hybrid alert's performance for identifying patients with a discharge diagnosis related to infection and modified sequential sepsis-related organ functional assessment (mSOFA) score ≥2 in ED and also compared the alert to rapid bedside screening tools to identify patients with infection for secondary outcomes of all-cause in-hospital death and/or intensive care unit admission. RESULTS: A total of 118 178 adult patients presented to participating EDs during study period with 1546 patients meeting ED sepsis criteria. The hybrid alert had a sensitivity - 71.2% (95% confidence interval 68.8-73.4), specificity - 96.4% (95% confidence interval 96.3-96.5) for identifying ED sepsis. Clinician flagging identified additional alert-negative 232 ED sepsis and 63 patients with secondary outcomes and 112 alert-positive patients with infection and ED mSOFA score <2 went on to die in hospital. CONCLUSION: The hybrid alert performed modestly in identifying ED sepsis and secondary outcomes from infection. Not all infected patients with a secondary outcome were identified by the alert or mSOFA score ≥2 threshold. Augmenting clinical practice with auto-alerts rather than pure automation should be considered as a potential for sepsis alerting until more reliable algorithms are available for safe use in clinical practice.

Reduction of in-hospital cardiac arrest rates in intensive care-equipped New South Wales hospitals in association with implementation of Between the Flags rapid response system.

BACKGROUND: The NSW Clinical Excellence commission introduced the 'Between the Flags' programme, in response to the death of a young patient, as a system-wide approach for early detection and management of the deteriorating patient in all NSW hospitals. The impact of BTF implementation on the 35 larger hospitals with intensive care units (ICU) has not been reported previously. AIM: To assess the impact of 'Between the Flags' (BTF), a two-tier rapid response system across 35 hospitals with an ICU in NSW, on the incidence of in-hospital cardiac arrests and the incidence and outcome of patients admitted to an ICU following cardiac arrest and rapid response team activation. METHODS: This is a prospective observational study of the BTF registry (August 2010 to June 2016) and the Australian and New Zealand Intensive Care Society Adult Patient Database (January 2008 to December 2016) in 35 New South Wales public hospitals with an ICU. The primary outcome studied was the proportion of in-hospital cardiac arrests. Secondary outcomes included changes in the severity of illness and outcomes of cardiac arrest admissions to the ICU and changes in the volume of rapid response calls. RESULTS: The cardiac arrest rate per 1000 hospital admissions declined from 0.91 in the implementation period to 0.70. Propensity score analysis showed significant declines in ICU and hospital mortality and length of stay for cardiac arrest patients admitted to the ICU (all P < 0.001). CONCLUSIONS: The BTF programme was associated with a significant reduction in cardiac arrests in hospitals and ICU admissions secondary to cardiac arrests in 35 NSW hospitals with an ICU.

Comparison of the quick Sepsis-related Organ Failure Assessment and adult sepsis pathway in predicting adverse outcomes among adult patients in general wards: a retrospective observational cohort study.

BACKGROUND: Quick Sepsis-related Organ Failure Assessment (qSOFA) is recommended for use by the most recent international sepsis definition taskforce to identify suspected sepsis in patients outside the intensive care unit (ICU) at risk of adverse outcomes. Evidence of its comparative effectiveness with existing sepsis recognition tools is important to guide decisions about its widespread implementation. AIM: To compare the performance of qSOFA with the adult sepsis pathway (ASP), a current sepsis recognition tool widely used in NSW hospitals and systemic inflammatory response syndrome criteria in predicting adverse outcomes in adult patients on general wards. METHODS: A retrospective observational cohort study was conducted which included all adults with suspected infections admitted to a Sydney teaching hospital between December 2014 and June 2016. The primary outcome was in-hospital mortality with two secondary composite outcomes. RESULTS: Among 2940 patients with suspected infection, 217 (7.38%) died in-hospital and 702 (23.88%) were subsequently admitted to ICU. The ASP showed the greatest ability to correctly discriminate in-hospital mortality and secondary outcomes. The area under the receiver-operating characteristic curve for mortality was 0.76 (95% confidence interval (CI): 0.74-0.78), compared to 0.64 for the qSOFA tool (95% CI: 0.61-0.67, P < 0.0001). Median time from the first ASP sepsis warning to death was 8.21 days (interquartile range (IQR): 2.29-16.75) while it was 0 days for qSOFA (IQR: 0-2.58). CONCLUSIONS: The ASP demonstrated both greater prognostic accuracy and earlier warning for in-hospital mortality for adults on hospital wards compared to qSOFA. Hospitals already using ASP may not benefit from switching to the qSOFA tool.

The effectiveness of a standardised rapid response system on the reduction of cardiopulmonary arrests and other adverse events among emergency surgical admissions.

AIM: A standardised rapid response system (RRS), called the "Between-the-Flags" (BTF) program, was implemented across a large health jurisdiction in Australia in 2010. The impact of RRS on emergency surgical admissions is unknown. METHODS: We linked the NSW Admitted Patient Data Collection (APDC) and the NSW Registry of Births, Deaths, and Marriages. We used a propensity score-based inverse-probability-weighting adjustment to estimated average treatment effects among treated subjects (prior-RRS hospitals vs prior-non-RRS hospitals) before the BTF implementation (2007-2008) and after (2010-2013). RESULTS: Before BTF, prior-RRS hospitals had a lower rate of in hospital cardiopulmonary arrests (IHCA) (4.7 vs 7.8 per 1000 admissions, P < 0.001), a lower rate of IHCA related deaths (3.0 vs 4.4 per 1000 admissions, P = 0.03) compared with patients in prior-non-RRS hospitals. There were no significant differences in overall in-hospital mortality and 30-day mortality between the two cohorts. After BTF, there were no significant differences for IHCA (4.8 vs 5.5 per 1000 admissions, P = 0.081) and related death rates (2.4 vs 2.3 per 1000 admissions, P = 0.678) between the two cohorts. Hospital mortality, 30-day mortality improved across both prior-RRS and prior-non-RRS hospitals following the BTF implementation. CONCLUSION: BTF program was associated with a significant reduction in IHCA and IHCA deaths for emergency surgical patients in prior-non-RRS hospitals but not in the prior-RRS hospitals. The overall hospital and 30-day mortality improved in both cohorts after BTF.

Improving the Performance of Clinical Decision Support for Early Detection of Sepsis: A Retrospective Observational Cohort Study.

Sepsis remains a significant global health problem. It is a life-threatening, but poorly defined and recognized condition. Early recognition and intervention are essential to optimize patient outcomes. Automated clinical decision support systems (CDS) may be particularly beneficial for early detection of sepsis. The aim of this study was to use retrospective data to develop and evaluate seven revised versions of an electronic sepsis alert rule to assess their performance in detecting sepsis cases and patient deterioration (in-hospital mortality or ICU admission). Four revised options had higher sensitivity but lower specificity than the original rule. After discussion with clinical experts, two revised options with the highest sensitivity were selected. Further analysis on the number of alerts and time intervals between alerts and patient outcomes was conducted to decide the option to be implemented. This study has provided a data-driven approach to improve the CDS on early detection of sepsis.

Geoff Cloke at 65: a pioneer in organometallic chemistry.

Professor Geoff Cloke FRS celebrates his 65th birthday in 2018. In a career spanning four decades, his research endeavours have accounted for some of the most innovative synthetic chemistry of the modern era, with his many publications describing truly exceptional compounds and experimental methods that portray a unique chemical imagination. In addition to his scientific accomplishments, Cloke can be particularly proud of his successful mentoring, a level of dedication that propelled many students and post-docs on to become research leaders in their own right. In compiling this collection of some of his research articles, a small cross-section of his friends, colleagues and collaborators, wish to pay tribute to his modesty, compassion and generous personality.

Comment on "Hydride, gold(i) and related derivatives of the unsaturated ditungsten anion [W2Cp2(µ-PCy2)(µ-CO)2]-" by M. A. Ruiz et al., Dalton Trans., 2014, 43, 16044.

Application of the covalent bond classification to the compounds [M2(η5-C5H5)2(µ-H)(µ-PCy2)(CO)2] (M = Mo, W) identifies the compounds as having two M-M bonds and a 2 electron 3 centre (2e-3c) bond incorporating the bridging hydrogen, in accord with density functional calculations, and assigns their class as ML4X4.

Serum lactate cut-offs as a risk stratification tool for in-hospital adverse outcomes in emergency department patients screened for suspected sepsis.

OBJECTIVES: We investigated specific lactate thresholds for adverse outcomes in patients presenting to emergency departments (EDs) with suspected sepsis identified based on the performance of a sepsis screening algorithm. DESIGN AND SETTING: A standardised sepsis bundle was implemented across public hospitals in New South Wales, Australia, as a quality improvement initiative. A register of all adult ED presentations (≥18 years) meeting predefined criteria for sepsis was created, using a combination of data linkage and direct reporting from 97 participating sites. PARTICIPANTS: A total of 12 349 adult ED presentations with 8310 (67.3%) having serum lactate analysis on arrival. Analysis of outcomes was based on dataset for 12 349 subjects obtained through multiple imputation for missing data. INTERVENTIONS: A sepsis management bundle including early antibiotic prescribing, fluid therapy and referral to intensive care unit (ICU) services was implemented. OUTCOME MEASURES: A primary composite adverse event (AE) outcome of inhospital mortality (IHM) and/or prolonged ICU stay ≥72 hours (ICU 72 hours) was used for this study. RESULTS: There was statistically significant increase both in the ORs of AE and IHM with each integer increase in serum lactate values. After adjusting for the presence of hypotension, the estimated ORs for the combined AE outcome were 2.71 (95% CI 2.05 to 3.57), 2.65 (95% CI 2.29 to 3.08), 3.10 (95% CI 2.71 to 3.53) and 3.89 (95% CI 3.36 to 4.50) for serum lactate levels at or above 1, 2, 3 and 4 mmol/L, respectively. The corresponding ORs for IHM were 2.93 (95% CI 2.08 to 4.13), 2.77 (95% CI 2.34 to 3.29), 3.26 (95% CI 2.80 to 3.80) and 4.01 (95% CI 3.40 to 4.73), respectively (all P<0.0001). More than 10% of patients with suspected sepsis and with serum lactate ≥2 mmol/L experienced a prolonged ICU stay or died in hospital. CONCLUSIONS: ED sepsis screening algorithms intended to identify patient adverse outcomes should incorporate a serum lactate cut-off of ≥2 mmol/L as a threshold for the initiation of specific interventions and increased monitoring.

Comparison of the Between the Flags calling criteria to the MEWS, NEWS and the electronic Cardiac Arrest Risk Triage (eCART) score for the identification of deteriorating ward patients.

INTRODUCTION: Traditionally, paper based observation charts have been used to identify deteriorating patients, with emerging recent electronic medical records allowing electronic algorithms to risk stratify and help direct the response to deterioration. OBJECTIVE(S): We sought to compare the Between the Flags (BTF) calling criteria to the Modified Early Warning Score (MEWS), National Early Warning Score (NEWS) and electronic Cardiac Arrest Risk Triage (eCART) score. DESIGN AND PARTICIPANTS: Multicenter retrospective analysis of electronic health record data from all patients admitted to five US hospitals from November 2008-August 2013. MAIN OUTCOME MEASURES: Cardiac arrest, ICU transfer or death within 24h of a score RESULTS: Overall accuracy was highest for eCART, with an AUC of 0.801 (95% CI 0.799-0.802), followed by NEWS, MEWS and BTF respectively (0.718 [0.716-0.720]; 0.698 [0.696-0.700]; 0.663 [0.661-0.664]). BTF criteria had a high risk (Red Zone) specificity of 95.0% and a moderate risk (Yellow Zone) specificity of 27.5%, which corresponded to MEWS thresholds of >=4 and >=2, NEWS thresholds of >=5 and >=2, and eCART thresholds of >=12 and >=4, respectively. At those thresholds, eCART caught 22 more adverse events per 10,000 patients than BTF using the moderate risk criteria and 13 more using high risk criteria, while MEWS and NEWS identified the same or fewer. CONCLUSION(S): An electronically generated eCART score was more accurate than commonly used paper based observation tools for predicting the composite outcome of in-hospital cardiac arrest, ICU transfer and death within 24h of observation. The outcomes of this analysis lend weight for a move towards an algorithm based electronic risk identification tool for deteriorating patients to ensure earlier detection and prevent adverse events in the hospital.

Lactate ≥2 mmol/L plus qSOFA improves utility over qSOFA alone in emergency department patients presenting with suspected sepsis.

OBJECTIVE: The Sepsis-3 task force recommends the use of the quick Sequential Organ Failure Assessment (qSOFA) score to identify risk for adverse outcomes in patients presenting with suspected infection. Lactate has been shown to predict adverse outcomes in patients with suspected infection. The aim of the study is to investigate the utility of a post hoc lactate threshold (≥2 mmol/L) added qSOFA score (LqSOFA(2) score) to predict primary composite adverse outcomes (mortality and/or ICU stay ≥72 h) in patients presenting to ED with suspected sepsis. METHODS: Retrospective cohort study was conducted on a merged dataset of suspected or proven sepsis patients presenting to ED across multiple sites in Australia and The Netherlands. Patients are identified as candidates for quality improvement initiatives or research studies at respective sites based on local screening procedures. Data-sharing was performed across sites of demographics, qSOFA, SOFA, lactate thresholds and outcome data for included patients. LqSOFA(2) scores were calculated by adding an extra point to qSOFA score in patients who met lactate thresholds of ≥2 mmol/L. RESULTS: In a merged dataset of 12 555 patients where a full qSOFA score and outcome data were available, LqSOFA(2) ≥2 identified more patients with an adverse outcome (sensitivity 65.5%, 95% confidence interval 62.6-68.4) than qSOFA ≥2 (sensitivity 47.6%, 95% confidence interval 44.6- 50.6). The post hoc addition of lactate threshold identified higher proportion of patients at risk of adverse outcomes. CONCLUSIONS: The lactate ≥2 mmol/L threshold-based LqSOFA(2) score performs better than qSOFA alone in identifying risk of adverse outcomes in ED patients with suspected sepsis.

Choking on a foreign body: a physiological study of the effectiveness of abdominal thrust manoeuvres to increase thoracic pressure.

The Heimlich manoeuvre is a well-known intervention for the management of choking due to foreign body airway occlusion, but the evidence base for guidance on this topic is limited and guidelines differ. We measured pressures during abdominal thrusts in healthy volunteers. The angle at which thrusts were performed (upthrust vs circumferential) did not affect intrathoracic pressure. Self-administered abdominal thrusts produced similar pressures to those performed by another person. Chair thrusts, where the subject pushed their upper abdomen against a chair back, produced higher pressures than other manoeuvres. Both approaches should be included in basic life support teaching.

Between the flags: implementing a safety-net system at scale to recognise and manage deteriorating patients in the New South Wales Public Health System.

QUALITY PROBLEM: In 2005, the Clinical Excellence Commission (CEC) found that unrecognised patient deterioration remained an important problem in New South Wales (NSW) public hospitals. INITIAL ASSESSMENT: The challenge was to design and implement an effective and sustainable safety-net system in all 225 NSW public hospitals. DESIGNING A SOLUTION: The CEC's system was designed in collaboration with a broad coalition of partners, including clinicians, managers, system administrators and collaborating agencies. A five-element system comprising governance, standard calling criteria in standard observation charts, two-level clinical emergency response systems (CERS) in each facility, an education programme and evaluation, was designed for state-wide implementation. This system was called 'Between the Flags' (BTF). IMPLEMENTATION: Implementation was led by the CEC on behalf of a NSW coalition, and commenced in January 2010 with the implementation of the Standard Adult General Observation Chart, awareness training for all staff and a CERS in each facility. EVALUATION: Since the introduction of BTF, the cardiac arrest rate has declined by 42% (P < 0.05) and the Rapid Response rate has increased by 135.9% (P < 0.05) in NSW. The strength of staff support for BTF has grown with the proportion of respondents strongly agreeing that BTF has benefitted patient safety more than doubling from 21% to 44%, and overall agreement rising from 68% to 82% between 2010 and 2012. LESSONS LEARNED: Key success factors are a focus on governance, standardisation of observation charts and striking the right balance between a rule-based approach and individual clinical judgement.

London ambulance source data on choking incidence for the calendar year 2016: an observational study.

INTRODUCTION: Complete foreign body airway obstruction is a life-threatening emergency, but there are limited data on its epidemiology. METHODS: We conducted a retrospective analysis of data collected routinely from London Ambulance Service calls coded as being for choking was undertaken for the calendar year of 2016. RESULTS: There were 1916 choking episodes of significant severity to call for emergency assessment in London during 2016, 0.2% of total calls requiring an ambulance response, an average of 5.2 per day. The incidence increased at the extremes of age. Calls coded as choking occurred at times consistent with lunch and dinner and less frequently at breakfast. Peak incidence occurred at Sunday lunchtimes and on Wednesday evenings. CONCLUSIONS: Choking is a substantial health problem for Londoners to seek emergency assistance. Choking is more frequent at the extremes of age with a higher incidence at lunch and dinner time. Greater public awareness of choking and its management could help to prevent avoidable deaths.