Adjusting Early Warning Score by clinical assessment: a study protocol for a Danish cluster-randomised, multicentre study of an Individual Early Warning Score (I-EWS).

INTRODUCTION: Track and trigger systems (TTSs) based on vital signs are implemented in hospitals worldwide to identify patients with clinical deterioration. TTSs may provide prognostic information but do not actively include clinical assessment, and their impact on severe adverse events remain uncertain. The demand for prospective, multicentre studies to demonstrate the effectiveness of TTSs has grown the last decade. Individual Early Warning Score (I-EWS) is a newly developed TTS with an aggregated score based on vital signs that can be adjusted according to the clinical assessment of the patient. The objective is to compare I-EWS with the existing National Early Warning Score (NEWS) algorithm regarding clinical outcomes and use of resources. METHOD AND ANALYSIS: In a prospective, multicentre, cluster-randomised, crossover, non-inferiority study. Eight hospitals are randomised to use either NEWS in combination with the Capital Region of Denmark NEWS Override System (CROS) or implement I-EWS for 6.5 months, followed by a crossover. Based on their clinical assessment, the nursing staff can adjust the aggregated score with a maximum of -4 or +6 points. We expect to include 150 000 unique patients. The primary endpoint is all-cause mortality at 30 days. Coprimary endpoint is the average number of times per day a patient is NEWS/I-EWS-scored, and secondary outcomes are all-cause mortality at 48 hours and at 7 days as well as length of stay. ETHICS AND DISSEMINATION: The study was presented for the Regional Ethics committee who decided that no formal approval was needed according to Danish law (J.no. 1701733). The I-EWS study is a large prospective, randomised multicentre study that investigates the effect of integrating a clinical assessment performed by the nursing staff in a TTS, in a head-to-head comparison with the internationally used NEWS with the opportunity to use CROS. TRIAL REGISTRATION NUMBER: NCT03690128.

Association between perioperative hyperoxia and cerebrovascular complications after laparotomy-A post-hoc follow-up study.

BACKGROUND: Perioperative hyperoxia has been linked to increased long-term mortality. Vasoconstrictive and cellular side effects to hyperoxia have been suggested to increase the risk of coronary and cerebral ischemia. The aim of this post-hoc analysis of a large randomized trial was to compare the effects of 80% vs 30% perioperative oxygen on the long-term risk of stroke or transient cerebral ischemia (TCI) in patients undergoing abdominal surgery. METHODS: A total of 1386 patients were randomized to 80% or 30% perioperative oxygen during acute or elective open abdominal surgery. Median follow-up was 3.9 years. Primary outcome was a composite of the long-term occurrence of stroke or TCI. Secondary outcomes included long-term mortality without stroke or TCI, and incidences of neurological admission, psychiatric admission, and dementia. Outcomes were analyzed in Cox regression models. RESULTS: Stroke or TCI occurred in 20 (3.0%) patients given 80% oxygen vs 22 (3.2%) patients given 30% oxygen with an adjusted hazard ratio (HR) of 0.96 [95% CI 0.52-1.76]. Composite secondary outcome of death, stroke, or TCI had a HR of 1.21 [95% CI 1.00-1.47] for 80% compared to 30% oxygen. HRs for secondary outcomes were HR 1.14 [95% CI 0.79-1.64] for neurological admission, 1.34 [95% CI 0.95-1.88] for psychiatric admission and 0.54 [95% CI 0.16-1.80] for dementia. CONCLUSION: Stroke or TCI did not seem related to perioperative inspiratory oxygen fraction. Due to few events, this study cannot exclude that perioperative hyperoxia increases risk of mortality, stroke, or TCI after abdominal surgery.

[Review of Early Warning Score in preventing sudden critical illness and death].

Early Warning Score (EWS) are used extensively to identify patients at risk of deterioration during hospital admission. The validation of EWS has primarily focused on investigating predictive validity, i.e. the association between EWS and severe adverse events. Few studies have tested, whether EWS work in the clinical setting, and if it prevents severe adverse events from occurring. Many of these studies have methodological limitations, and their clinical relevance could be questioned. Currently, there is limited evidence to support, that the implementation of EWS reduces the occurrence of severe adverse events.

Towards an automated multimodal clinical decision support system at the post anesthesia care unit.

BACKGROUND: The aim of this study was to develop a predictive algorithm detecting early signs of deterioration (ESODs) in the post anesthesia care unit (PACU), thus being able to intervene earlier in the future to avoid serious adverse events. The algorithm must utilize continuously collected cardiopulmonary vital signs and may serve as an alternative to current practice, in which an alarm is activated by single parameters. METHODS: The study was a single center, prospective cohort study including 178 patients admitted to the PACU after major surgical procedures. Peripheral blood oxygenation, arterial blood pressure, perfusion index, heart rate and respiratory rate were monitored continuously. Potential ESODs were automatically detected and scored by two independent experts with regards to the severity of the observation. Based on features extracted from the obtained measurements, a random forest classifier was trained, classifying each event being either an ESOD or not an ESOD. The algorithm was evaluated and compared to the automated single modality alarm system at the PACU. RESULTS: The algorithm detected ESODs with an accuracy of 92.2% (99% CI: 89.6%-94.8%), sensitivity of 90.6% (99% CI: 85.7%-95.5%), specificity of 93.0% (99% CI: 89.9%-96.2%) and area under the receiver operating characteristic curve of 96.9% (99% CI: 95.3%-98.5%). The number of false alarms decreased by 85% (99% CI: 77%-93%) and the number of missed ESODs decreased by 73% (99% CI: 61%-85%) as compared to the currently used alarm system in the hospital. The algorithm was able to detect an ESOD in average 26.4 (99% CI: 1.1-51.7) minutes before the current single parameter system used in the PACU. CONCLUSION: In conclusion, the proposed biomedical classification algorithm, when compared to the currently used single parameter alarm system of the hospital, showed significantly increased performance in both detecting ESODs fast and classifying these correctly. The clinical effect of the predictive system must be evaluated in future trials.

[Practical management of troponin screening after non-cardiac surgery].

Myocardial injury after non-cardiac surgery (MINS) is associated with significant morbidity and mortality. Routine troponin screening is necessary to identify patients with MINS. Although some evidence indicates benefit with aspirin and statin therapy in these patients, a number of clinical considerations must be done in the practical management of MINS. This article describes current experience with identification and treatment in Denmark of patients with MINS.

Perioperative hyperoxia - Long-term impact on cardiovascular complications after abdominal surgery, a post hoc analysis of the PROXI trial.

BACKGROUND: Increased long-term mortality was found in patients exposed to perioperative hyperoxia in the PROXI trial, where patients undergoing laparotomy were randomised to 80% versus 30% oxygen during and after surgery. This post hoc follow-up study assessed the impact of perioperative hyperoxia on long-term risk of cardiovascular events. METHODS: A total of 1386 patients undergoing either elective or emergency laparotomy were randomised to 80% versus 30% oxygen during and two hours after surgery. At follow-up, the primary outcome of acute coronary syndrome was assessed. Secondary outcomes included myocardial infarction, other heart disease, and acute coronary syndrome or death. Data were analysed in the Cox proportional hazards model. RESULTS: The primary outcome, acute coronary syndrome, occurred in 2.5% versus 1.3% in the 80% versus 30% oxygen group; HR 2.15 (95% CI 0.96-4.84). Patients in the 80% oxygen group had significantly increased risk of myocardial infarction; HR 2.86 (95% CI 1.10-7.44), other heart disease; HR 1.40 (95% 1.06-1.83), and acute coronary syndrome or death; HR 1.22 (95% CI 1.01-1.49). CONCLUSIONS: Perioperative hyperoxia may be associated with an increased long-term risk of myocardial infarction and other heart disease.