Glucose as an additional parameter to National Early Warning Score (NEWS) in prehospital setting enhances identification of patients at risk of death: an observational cohort study.

BACKGROUND: To determine if prehospital blood glucose could be added to National Early Warning Score (NEWS) for improved identification of risk of short-term mortality. METHODS: Retrospective observational study (2008-2015) of adult patients seen by emergency medical services in Helsinki metropolitan area for whom all variables for calculation of NEWS and a blood glucose value were available. Survival of 24 hours and 30 days were determined. The NEWS parameters and glucose were tested by multivariate logistic regression model. Based on ORs we formed NEWSgluc model with hypoglycaemia (≤3.0 mmol/L) 3, normoglycaemia 0 and hyperglycaemia (≥11.1 mmol/L) 1 points. The scores from NEWS and NEWSgluc were compared using discrimination (area under the curve), calibration (Hosmer-Lemeshow test), likelihood ratio tests and reclassification (continuous net reclassification index (cNRI)). RESULTS: Data of 27 141 patients were included in the study. Multivariable regression model for NEWSgluc parameters revealed a strong association with glucose disturbances and 24-hour and 30-day mortality. Likelihood ratios (LRs) for mortality at 24 hours using a cut-off point of 15 were for NEWSgluc: LR+ 17.78 and LR- 0.96 and for NEWS: LR+ 13.50 and LR- 0.92. Results were similar at 30 days. Risks per score point estimation and calibration model showed glucose added benefit to NEWS at 24 hours and at 30 days. Although areas under the curve were similar, reclassification test (cNRI) showed overall improvement of classification of survivors and non-survivors at 24 days and 30 days with NEWSgluc. CONCLUSIONS: Including glucose in NEWS in the prehospital setting seems to improve identification of patients at risk of death.

Development and internal validation of an algorithm for estimating mortality in patients encountered by physician-staffed helicopter emergency medical services.

BACKGROUND: Severity of illness scoring systems are used in intensive care units to enable the calculation of adjusted outcomes for audit and benchmarking purposes. Similar tools are lacking for pre-hospital emergency medicine. Therefore, using a national helicopter emergency medical services database, we developed and internally validated a mortality prediction algorithm. METHODS: We conducted a multicentre retrospective observational register-based cohort study based on the patients treated by five physician-staffed Finnish helicopter emergency medical service units between 2012 and 2019. Only patients aged 16 and over treated by physician-staffed units were included. We analysed the relationship between 30-day mortality and physiological, patient-related and circumstantial variables. The data were imputed using multiple imputations employing chained equations. We used multivariate logistic regression to estimate the variable effects and performed derivation of multiple multivariable models with different combinations of variables. The models were combined into an algorithm to allow a risk estimation tool that accounts for missing variables. Internal validation was assessed by calculating the optimism of each performance estimate using the von Hippel method with four imputed sets. RESULTS: After exclusions, 30 186 patients were included in the analysis. 8611 (29%) patients died within the first 30 days after the incident. Eleven predictor variables (systolic blood pressure, heart rate, oxygen saturation, Glasgow Coma Scale, sex, age, emergency medical services vehicle type [helicopter vs ground unit], whether the mission was located in a medical facility or nursing home, cardiac rhythm [asystole, pulseless electrical activity, ventricular fibrillation, ventricular tachycardia vs others], time from emergency call to physician arrival and patient category) were included. Adjusted for optimism after internal validation, the algorithm had an area under the receiver operating characteristic curve of 0.921 (95% CI 0.918 to 0.924), Brier score of 0.097, calibration intercept of 0.000 (95% CI -0.040 to 0.040) and slope of 1.000 (95% CI 0.977 to 1.023). CONCLUSIONS: Based on 11 demographic, mission-specific, and physiologic variables, we developed and internally validated a novel severity of illness algorithm for use with patients encountered by physician-staffed helicopter emergency medical services, which may help in future quality improvement.

Mechanisms of early glucose regulation disturbance after out-of-hospital cardiopulmonary resuscitation: An explorative prospective study.

BACKGROUND: Hyperglycemia is common and associated with increased mortality after out-of-hospital cardiac arrest (OHCA) and return of spontaneous circulation (ROSC). Mechanisms behind ultra-acute hyperglycemia are not well known. We performed an explorative study to describe the changes in glucose metabolism mediators during the prehospital postresuscitation phase. METHODS: We included patients who were successfully resuscitated from out-of-hospital cardiac arrest in two physician-staffed units. Insulin, glucagon, and glucagon-like peptide 1 (GLP-1) were measured in prehospital and hospital admission samples. Additionally, interleukin-6 (IL-6), cortisol, and HbA1c were measured at hospital admission. RESULTS: Thirty patients participated in the study. Of those, 28 cases (71% without diabetes) had sufficient data for analysis. The median time interval between prehospital samples and hospital admission samples was 96 minutes (IQR 85-119). At the time of ROSC, the patients were hyperglycemic (11.2 mmol/l, IQR 8.8-15.7), with insulin and glucagon concentrations varying considerably, although mostly corresponding to fasting levels (10.1 mU/l, IQR 4.2-25.2 and 141 ng/l, IQR 105-240, respectively). GLP-1 increased 2- to 8-fold with elevation of IL-6. The median glucose change from prehospital to hospital admission was -2.2 mmol/l (IQR -3.6 to -0.2). No significant correlations between the change in plasma glucose levels and the changes in insulin (r = 0.30, p = 0.13), glucagon (r = 0.29, p = 0.17), or GLP-1 levels (r = 0.32, p = 0.15) or with IL-6 (r = (-0.07), p = 0.75), cortisol (r = 0.13, p = 0.52) or HbA1c levels (r = 0.34, p = 0.08) were observed. However, in patients who did not receive exogenous epinephrine during resuscitation, changes in blood glucose correlated with changes in insulin (r = 0.59, p = 0.04) and glucagon (r = 0.65, p = 0.05) levels, demonstrating that lowering glucose values was associated with a simultaneous lowering of insulin and glucagon levels. CONCLUSIONS: Hyperglycemia is common immediately after OHCA and cardiopulmonary resuscitation. No clear hormonal mechanisms were observed to be linked to changes in glucose levels during the postresuscitation phase in the whole cohort. However, in patients without exogenous epinephrine treatment, the correlations between glycemic and hormonal changes were more obvious. These results call for future studies examining the mechanisms of postresuscitation hyperglycemia and the metabolic effects of the global ischemic insult and medical treatment.

Hypoglycaemia without diabetes encountered by emergency medical services: a retrospective cohort study.

BACKGROUND: The current study investigates the incidence, aetiology, and outcome of hypoglycaemia of patients without diabetes in the EMS. METHODS: The study was a retrospective cohort study that utilized electronic EMS patient record system (population of one million). All patients encountered by EMS with plasma glucose ≤3.9 mmol/l from 2009 to 2015 were included in the study and hospital records were screened manually to detect possible reasons for hypoglycaemia. Data from the governmental health insurance agency for all residents in Finland was used to reveal the diabetes status of the patients. Survival of the patients was followed from Population register centre up to six years. Serious hypoglycaemia was defined as plasma glucose ≤3.0 mmol/l. RESULTS: From EMS cases with a plasma glucose measurement a total of 5467 hypoglycaemic patients without diabetes were encountered by EMS during the study period with an incidence of 1082 (CI95% 1019-1148) per 100,000 inhabitants per year, corresponding 41.6%, (CI95% 40.8-42.3) of all hypoglycaemic patients. Of those patients, 3856 [71.6%, (CI95% 70.4-72.8)] were transported to hospital and 910 [23.2%, (CI95% 22.0-24.6)] had serious hypoglycaemia. The three main diagnosis groups that appeared in the subsequent hospital treatment associated with hypoglycaemia in all transported cases without diabetes as well with serious hypoglycaemia cases were: alcohol abuse [41.2%, (CI95% 39.7-42.8) and 42.2%, (CI95% 39.0-45.4)], hypothermia [17.2%, (CI95% 16.0-18.4) and 27.4%, (CI95% 24.6-30.4)], and malnutrition [16.9%, (CI95% 15.8-18.1) and 25.1%, (CI95% 22.4-28.0)]. Mortality ranged from 0.6-65.4% depending of admission reason and increased significantly at long-term. Non-Diabetics survival was less than with diabetics, when serious hypoglycaemia was present. DISCUSSION: The most common possible hypoglycaemia related aetiological causes encountered in the EMS, alcohol abuse, hypothermia, and malnutrition, although frequent are often relatively benign conditions. These possible causes of hypoglycaemia can often be treated at scene or need only short hospital admissions. Hence they are not so prevalent in hospital studies. CONCLUSIONS: Hypoglycaemia without diabetes is commonly observed among the hypoglycaemic EMS cases. Main causes for it are alcohol abuse, hypothermia, and malnutrition. Mortality correlated with age, higher priority dispatch codes, and plasma glucose rate in multivariate logistic regression analysis. Some of the etiological subgroups carry a markedly high mortality rate.

Ultra-acute increase in blood glucose during prehospital phase is associated with worse short-term and long-term survival in ST-elevation myocardial infarction.

BACKGROUND: The current study was to investigate the blood glucose changes in ultra-acute phase in patients with ST-elevation myocardial infarction (STEMI) and its associations with patient outcome. METHODS: This study was a retrospective population-based observational study utilizing prospectively collected registry data complemented with laboratory data. All adult patients with STEMI treated by emergency medical services (EMS) in the city of Helsinki from January 2006 to December 2010 were included in the study. Both prehospital and hospital admission glucose values were available from 152 (32%) of all STEMI patients (n = 469). RESULTS: Change in blood glucose from prehospital phase to emergency department admission was significantly higher in non-survivors within 30 days compared to survivors (+1.2 ± 5.1 vs. -0.3 ± 2.4 mmol/l [mean ± SD], P = 0.03). Furthermore, the 3-year survival rate was significantly lower in patients with an evident (≥2 mmol/l) rise in blood glucose (P = 0.02). In patients with impaired left ventricle function (best ejection fraction < 40%), blood glucose increased more compared to patients without it (1.2 ± 2.9 vs. 0.4 ± 2.7 mmol/l, P = 0.01). Increase in glucose was correlated with peak myocardial creatinine kinase (r = 0.17, P = 0.04) as a marker of increased size of infarct, but not with glycosylated haemoglobin A1C as a marker of chronic hyperglycaemia (r = -0.12, P = 0.27). CONCLUSIONS: In patients with STEMI, ultra-acute hyperglycaemia during prehospital phase is associated with increased mortality, impaired cardiac function and increased size of infarct.