A standard operating procedure for prehospital anaesthesia and its effect on mortality-An observational study.

BACKGROUND: Prehospital anaesthesia is a complex intervention performed for critically ill patients. To minimise complications, a standard operating procedure (SOP) outlining the process is considered valuable. We investigated the implementation of an SOP for prehospital anaesthesia in helicopter emergency medical services (HEMS). METHODS: We performed a retrospective observational study of patients receiving prehospital anaesthesia by Finnish HEMS from January 2012 to August 2019. The intervention studied was the implementation of an SOP at two of the five bases during 2015-2016. Patients were stratified according to whether they were anaesthetised before, during or after implementation and the primary outcomes were 1- and 30-day mortality. Secondary outcomes included anaesthesia quality indicators. Confounding factors was assessed via logistic regression. RESULTS: A total of 3902 tracheal intubations were performed without an SOP, 430 during implementation and 1525 after implementation. The SOP had a significant effect on 1-day mortality during implementation with an odds ratio (OR) of 0.56, 95% confidence interval (95% CI) 0.37-0.81 and a further trend towards benefit after implementation (OR 0.84, 95% CI 0.68-1.04), but no difference in 30-day mortality (OR after implementation 1.10, 95% CI 0.92-1.30). Implementation of an SOP improved first-pass success rate from 87.3% to 96.5%, p < 0.001. CONCLUSION: Implementation of an SOP for prehospital anaesthesia was associated with a trend towards lower 1-day mortality and an improved first-pass success but did not affect 30-day mortality. Despite this, we advocate prehospital systems to consider implementation of a prehospital anaesthesia SOP as immediate performance markers improved significantly.

Intubation first-pass success in a high performing pre-hospital critical care system is not associated with 30-day mortality: a registry study of 4496 intubation attempts.

BACKGROUND: Lower intubation first-pass success (FPS) rate is associated with physiological deterioration, and FPS is widely used as a quality indicator of the airway management of a critically ill patient. However, data on FPS's association with survival is limited. We aimed to investigate if the FPS rate is associated with 30-day mortality or physiological complications in a pre-hospital setting. Furthermore, we wanted to describe the FPS rate in Finnish helicopter emergency medical services. METHODS: This was a retrospective observational study. Data on drug-facilitated intubation attempts by helicopter emergency medical services were gathered from a national database and analysed. Multivariate logistic regression, including known prognostic factors, was performed to assess the association between FPS and 30-day mortality, collected from population registry data. RESULTS: Of 4496 intubation attempts, 4082 (91%) succeeded on the first attempt. The mortality rates in FPS and non-FPS patients were 34% and 38% (P = 0.21), respectively. The adjusted odds ratio of FPS for 30-day mortality was 0.88 (95% CI 0.66-1.16). Hypoxia after intubation and at the time of handover was more frequent in the non-FPS group (12% vs. 5%, P < 0.001, and 5% vs. 3%, P = 0.01, respectively), but no significant differences were observed regarding other complications. CONCLUSION: FPS is not associated with 30-day mortality in pre-hospital critical care delivered by advanced providers. It should therefore be seen more as a process quality indicator instead of a risk factor of poor outcome, at least considering the current limitations of the parameter.

Prehospital characteristics of COVID-19 patients in Helsinki - experience of the first wave of the pandemic.

BACKGROUND: There is a lack of knowledge how patients with COVID-19 disease differ from patients with similar signs or symptoms (but who will have a diagnosis other than COVID-19) in the prehospital setting. The aim of this study was to compare the characteristics of these two patient groups met by the emergency medical services. METHODS: All prehospital patients after the World Health Organisation (WHO) pandemic declaration 11.3.2020 until 30.6.2020 were recruited for the study. The patients were screened using modified WHO criteria for suspected COVID-19. Data from the electronic prehospital patient reporting system were linked with hospital laboratory results to check the laboratory confirmation for COVID-19. For comparison, we divided the patients into two groups: screening- and laboratory-positive patients with a hospital diagnosis of COVID-19 and screening-positive but laboratory-negative patients who eventually received a different diagnosis in hospital. RESULTS: A total of 4157 prehospital patients fulfilled the criteria for suspected COVID-19 infection during the study period. Five-hundred-thirty-six (12.9%) of the suspected cases received a laboratory confirmation for COVID-19. The proportion of positive cases in relation to suspected ones peaked during the first 2 weeks after the declaration of the pandemic. In the comparison of laboratory-positive and laboratory-negative cases, there were clinically insignificant differences between the groups in age, tympanic temperature, systolic blood pressure, heart rate, on-scene time, urgency category of the call and mode of transportation. Foreign-language-speakers were overrepresented amongst the positive cases over native language speakers (26,6% vs. 7,4%, p < 0,001). The number of cases in which no signs or symptoms of COVID-19 disease were reported, but patients turned out to have a positive test result was 125 (0,3% of the whole EMS patient population and 11,9% of all verified COVID-19 patients encountered by the EMS). CONCLUSIONS: In a sample of suspected COVID-19 patients, the laboratory-positive and laboratory-negative patients were clinically indistinguishable from each other during the prehospital assessment. Foreign-language-speakers had a high likelihood of having Covid-19. The modified WHO criteria still form the basis of screening of suspected COVID-19 patients in the prehospital setting.

Ability of prehospital NEWS to predict 1-day and 7-day mortality is reduced in older adult patients.

BACKGROUND: National Early Warning Score (NEWS) does not include age as a parameter despite age is a significant independent risk factor of death. The aim of this study was to examine whether age has an effect on predictive performance of short-term mortality of NEWS in a prehospital setting. We also evaluated whether adding age as an additional parameter to NEWS improved its short-term mortality prediction. METHODS: We calculated NEWS scores from retrospective prehospital electronic patient record data for patients 18 years or older with sufficient prehospital data to calculate NEWS. We used area under receiver operating characteristic (AUROC) to analyse the predictive performance of NEWS for 1 and 7 day mortalities with increasing age in three different age groups: <65 years, 65-79 years and ≥80 years. We also explored the ORs for mortality of different NEWS parameters in these age groups. We added age to NEWS as an additional parameter and evaluated its effect on predictive performance. RESULTS: We analysed data from 35 800 ambulance calls. Predictive performance for 7-day mortality of NEWS decreased with increasing age: AUROC (95% CI) for 1-day mortality was 0.876 (0.848 to 0.904), 0.824 (0.794 to 0.854) and 0.820 (0.788 to 0.852) for first, second and third age groups, respectively. AUROC for 7-day mortality had a similar trend. Addition of age as an additional parameter to NEWS improved its ability to predict short-term mortality when assessed with continuous Net Reclassification Improvement. CONCLUSIONS: Age should be considered as an additional parameter to NEWS, as it improved its performance in predicting short-term mortality in this prehospital cohort.

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.

Paediatric prehospital emergencies and restrictions during the COVID-19 pandemic: a population-based study.

BACKGROUND: Children are less vulnerable to serious forms of the COVID-19 disease. However, concerns have been raised about children being the second victims of the pandemic and its control measures. Therefore, we wanted to study if the pandemic, the infection control measures and their consequences to the society projected to paediatric prehospital emergency medical services (EMS) contacts. METHODS: We conducted a population-based cohort study concerning all children aged 0-15 years with EMS contacts in the Helsinki University Hospital area during 1 March 2020-31 May 2020 (study period) and equivalent periods in 2017-2019 (control periods). We analysed the demographic characteristics, time of EMS contact, reason for EMS contact, priority of the dispatch, reason for transportation, priority of transportation, if any consultations were made or additional units required, any medication or oxygen or fluids given, if intubation was performed, and whether paramedics took precautions when COVID-19 infection was suspected. RESULTS: The number of paediatric EMS contacts decreased by 30.4% from mean of 1794 contacts to 1369 (p=0.003). The EMS contacts were more often due to trauma (+23.7%, p<0.05), dispatched in the most urgent category (+139.9%, p=0.001), additional help and the mobile intensive care unit were more frequently requested (+43.3%, p=0.040 and+46.3%, p=0.049, respectively). However, EMS contacts resulted less often in ambulance transport (-21.1%, p<0.001). Alarmingly, there were four deaths during the study period compared with 0-2 during the control periods. CONCLUSIONS: The number of EMS contacts decreased during the pandemic. Nevertheless, the children encountered by the EMS were more seriously ill than during the control periods.

Random forest machine learning method outperforms prehospital National Early Warning Score for predicting one-day mortality: A retrospective study.

AIM OF THE STUDY: The National Early Warning Score (NEWS) is a validated method for predicting clinical deterioration in hospital wards, but its performance in prehospital settings remains controversial. Modern machine learning models may outperform traditional statistical analyses for predicting short-term mortality. Thus, we aimed to compare the mortality prediction accuracy of NEWS and random forest machine learning using prehospital vital signs. METHODS: In this retrospective study, all electronic ambulance mission reports between 2008 and 2015 in a single EMS system were collected. Adult patients (≥ 18 years) were included in the analysis. Random forest models with and without blood glucose were compared to the traditional NEWS for predicting one-day mortality. A ten-fold cross-validation method was applied to train and validate the random forest models. RESULTS: A total of 26,458 patients were included in the study of whom 278 (1.0%) died within one day of ambulance mission. The area under the receiver operating characteristic curve for one-day mortality was 0.836 (95% CI, 0.810-0.860) for NEWS, 0.858 (95% CI, 0.832-0.883) for a random forest trained with NEWS variables only and 0.868 (0.843-0.892) for a random forest trained with NEWS variables and blood glucose. CONCLUSION: A random forest algorithm trained with NEWS variables was superior to traditional NEWS for predicting one-day mortality in adult prehospital patients, although the risk of selection bias must be acknowledged. The inclusion of blood glucose in the model further improved its predictive performance.

Prehospital National Early Warning Score predicts early mortality.

BACKGROUND: National Early Warning Score (NEWS) has been shown to be the best early warning score to predict in-hospital mortality but there is limited information on its predictive value in a prehospital setting. The aim of the current study was to investigate the diagnostic accuracy of NEWS in a prehospital setting using large population-based databases in terms of short-term mortality. METHODS: We calculated the NEWS scores from retrospective prehospital electronic patient record data and analysed their possible relationship to mortality. We included all patient records for patients 18 years or older with sufficient prehospital data to calculate NEWS from 17 August 2008 to 18 December 2015 encountered by the emergency medical services (EMS) in the Hospital District of Helsinki and Uusimaa, Finland. The primary outcome measure was death within 1 day of EMS dispatch. RESULTS: 35 800 patients were included. Their mean (SD) age was 65.8 (19.9) years. The median value of NEWS was 3 (IQR 1-6). The primary outcome of death within 1 day of EMS dispatch occurred in 378 (1.1%) cases. Area under receiver operating characteristic curve (AUROC) for primary outcome of death within 1 day was 0.840 (95% CI 0.823-0.858). AUROC for 1 day mortality in trauma subgroup was 0.901 (95% CI 0.859-0.942). CONCLUSION: Prehospital NEWS predicts mortality within 1 day of EMS dispatch with good diagnostic accuracy.

Urgent EMS managed out-of-hospital delivery dispatches in Helsinki.

BACKGROUND: The aim of this study was to examine Helsinki Emergency Medical Services (EMS) and hospital records to determine the incidence and possible complications of out-of-hospital deliveries managed by EMS in Helsinki. METHODS: We retrospectively analysed all urgent ambulance dispatches relating to childbirth in Helsinki from January 1, 2010 to December 31, 2014 with further analysis of hospital records for the out-of-hospital deliveries. Patients were divided in to two groups: those who delivered before reaching hospital and those who did not deliver before reaching hospital and differences between groups were analysed. Deliveries with gestational age of at least 22 + 0 weeks were considered as births in statistical analysis as this is the current national practice. RESULTS: There were 799 urgent dispatches during the study period. In 102 (12.8 %) of these delivery took place before reaching the hospital. The incidence of EMS managed out-of-hospital delivery was found to be 3.0/1000 births. The annual number of out-of-hospital deliveries attended by EMS increased from 15 in 2010 to 28 in 2014. No stillbirths were reported. Neither maternal or perinatal deaths nor major maternal complications were noted in the study population. DISCUSSION: Out-of-hospital deliveries represent a small minority of EMS calls and remain a challenge to maintaining professional capabilities. Small sample size might have limited the ability of the study to pick up rare complications. CONCLUSIONS: The amount of out-of-hospital deliveries in Helsinki increased during the five-year study period. There were no maternal or perinatal mortality or major complications resulting in long-term sequelae associated with the EMS-managed out-of-hospital births.

Critically ill patients in emergency department may be characterized by low amplitude and high variability of amplitude of pulse photoplethysmography.

BACKGROUND: The aim of the present pilot study was to determine if pulse photoplethysmography amplitude (PPGA) could be used as an indicator of critical illness and as a predictor of higher need of care in emergency department patients. METHODS: This was a prospective observational study. We collected vital signs and one minute of pulse photoplethysmograph signal from 251 consecutive patients admitted to a university hospital emergency department. The patients were divided in two groups regarding to the modified Early Warning Score (mEWS): > 3 (critically ill) and ≤ 3 (non-critically ill). Photoplethysmography characteristics were compared between the groups. RESULTS: Sufficient data for analysis was acquired from 212 patients (84.5%). Patients in critically ill group more frequently required intubation and invasive hemodynamic monitoring in the ED and received more intravenous fluids. Mean pulse photoplethysmography amplitude (PPGA) was significantly lower in critically ill patients (median 1.105 [95% CI of mean 0.9946-2.302] vs. 2.476 [95% CI of mean 2.239-2.714], P = 0.0257). Higher variability of PPGA significantly correlated with higher amount of fluids received in the ED (r = 0.1501, p = 0.0296). CONCLUSIONS: This pilot study revealed differences in PPGA characteristics between critically ill and non-critically ill patients. Further studies are needed to determine if these easily available parameters could help increase accuracy in triage when used in addition to routine monitoring of vital signs.

Characteristics of fibers formed by cytochrome c and induced by anionic phospholipids.

Recent publications described the formation of millimeter-length fibers by diverse lipid-binding proteins (e.g., histone H1, cytochrome c, indolicidin, and endostatin) when they are mixed with 80:20 phosphatidylcholine/phosphatidylserine vesicles. Further, these fibers displayed amyloid characteristics when stained with Congo Red. In the study presented here, we found by FTIR the amide I absorption band to reveal significant variation in fibers formed by cytochrome c, with some consisting of cytochrome c in a nativelike conformation and some exhibiting strong amyloid (beta-sheet) characteristics. Protein structure also varied from amyloid to nearly native within single fibers. Fibers were frequently blue or bluish and sometimes iridescent, likely due to interference of light in the fibers. The amyloid-type amide I band was observed for blue fibers only. AFM shows that fibers consist of smaller 3-4 nm diameter fibers with 10 nm lateral spacing.

Mutational analysis and membrane-interactions of the beta-sheet-like N-terminal domain of the pediocin-like antimicrobial peptide sakacin P.

To gain insight into how the N-terminal three-stranded beta-sheet-like domain in pediocin-like antimicrobial peptides positions itself on membranes, residues in the well-conserved (Y)YGNGV-motif in the domain were substituted and the effect of the substitutions on antimicrobial activity and binding of peptides to liposomes was determined. Peptide-liposome interactions were detected by measuring tryptophan-fluorescence upon exposing liposomes to peptides in which a tryptophan residue had been introduced in the N-terminal domain. The results revealed that the N-terminal domain associates readily with anionic liposomes, but not with neutral liposomes. The electrostatic interactions between peptides and liposomes facilitated the penetration of some of the peptide residues into the liposomes. Measuring the antimicrobial activity of the mutated peptides revealed that the Tyr2Leu and Tyr3Leu mutations resulted in about a 10-fold reduction in activity, whereas the Tyr2Trp, Tyr2Phe, Tyr3Trp and Tyr3Phe mutations were tolerated fairly well, especially the mutations in position 3. The Val7Ile mutation did not have a marked detrimental effect on the activity. The Gly6Ala mutation was highly detrimental, consistent with Gly6 being in one of the turns in the beta-sheet-like N-terminal domain, whereas the Gly4Ala mutation was tolerated fairly well. All mutations involving Asn5, including the conservative mutations Asn5Gln and Asn5Asp, were very deleterious. Thus, both the polar amide group on the side chain of Asn5 and its exact position in space were crucial for the peptides to be fully active. Taken together, the results are consistent with Val7 positioning itself in the hydrophobic core of target membranes, thus forcing most of the other residues in the N-terminal domain into the membrane interface region: Tyr3 and Asn5 in the lower half with their side chains pointing downward and approaching the hydrophobic core, Tyr2, Gly4 and His8 and 12 in the upper half, Lys1 near the middle of the interface region, and the side chain of Lys11 pointing out toward the membrane surface.