The effect of time of measurement on the discriminant ability for mortality in trauma of a pre-hospital shock index multiplied by age and divided by the Glasgow Coma Score: a registry study.

BACKGROUND: The shock index (SI) and its derivatives have been shown to predict mortality in severely injured patients, both in pre-hospital and in-hospital settings. However, the impact of the time of measurement on the discriminative ability of the pre-hospital SI is unknown. The aim of this study was to evaluate whether the time of measurement influences the discriminative ability of the SI multiplied by age (SIA) and divided by the Glasgow Coma Score (SIA/G). METHODS: Registry data were obtained from the national helicopter emergency medical services (HEMS) on trauma patients aged ≥ 18 years. The SI values were calculated based on the first measured vitals of the trauma patients by the HEMS unit. The discriminative ability of the SIA/G, with 30-day mortality as the endpoint, was evaluated according to different delay times (0 - 19, 20 - 39 and ≥ 40 min) from the initial incident. Sub-group analyses were performed for trauma patients without a traumatic brain injury (TBI), patients with an isolated TBI and patients with polytrauma, including a TBI. RESULTS: In total, 3,497 patients were included in the study. The SIA/G was higher in non-survivors (median 7.8 [interquartile range 4.7-12.3] vs. 2.4 [1.7-3.6], P < 0.001). The overall area under the receiver operator characteristic curve (AUROC) for the SIA/G was 0.87 (95% CI: 0.85-0.89). The AUROC for the SIA/G was similar in the short (0.88, 95% CI: 0.85-0.91), intermediate (0.86, 95% CI: 0.84-0.89) and long (0.86, 95% CI: 0.82-0.89) measurement delay groups. The findings were similar in the three trauma sub-groups. CONCLUSIONS: The discriminative ability of the SIA/G in predicting 30-day mortality was not significantly affected by the measurement time of the index in the pre-hospital setting. The SIA/G is a simple and reliable tool for assessing the risk of mortality among severely injured patients in the pre-hospital setting.

Predictive value of shock index variants on 30-day mortality of trauma patients in helicopter emergency medical services: a nationwide observational retrospective multicenter study.

The original shock index (SI) has been further developed to increase its prognostic value. We aimed to evaluate the predictive value of different SI variants on 30-day mortality among severely injured trauma patients in pre-hospital critical care settings. Adult trauma patients in the national Helicopter Emergency Medical Services (HEMS) registry were evaluated based on the primary outcome of 30-day mortality. SI, SIA (SI multiplied by age), SI/G (SI divided by Glasgow Coma Scale (GCS)), SIA/G (SI multiplied by age and divided by GCS), and SS (SI divided by oxygen saturation) were calculated based on the first vital signs measured at the time of HEMS contact. The area under the receiver operating curve (AUROC) was calculated for each SI variant. In total 4108 patients were included in the study. The overall 30-day mortality was 13.5%. The SIA/G and SI/G had the highest predictive ability (AUROC 0.884 [95% CI 0.869-0.899] and 0.8000 [95% CI 0.7780-0.8239], respectively). The SIA/G yielded good predictive performance between 30-day survivors and non-survivors in the pre-hospital critical care setting.

Accuracy of prehospital clinicians' perceived prognostication of long-term survival in critically ill patients: a nationwide retrospective cohort study on helicopter emergency service patients.

OBJECTIVES: Prehospital critical care physicians regularly attend to patients with poor prognosis and may limit the advanced therapies. The aim of this study was to evaluate the accuracy of poor prognosis given by prehospital critical care clinicians. DESIGN: Cohort study. SETTING: We performed a retrospective cohort study using the national helicopter emergency medical services (HEMS) quality database. PARTICIPANTS: Patients classified by the HEMS clinician to have survived until hospital admission solely because of prehospital interventions but evaluated as having no long-term survival by prehospital clinician, were included. PRIMARY AND SECONDARY OUTCOME: The survival of the study patients was examined at 30 days, 1 year and 3 years. RESULTS: Of 36 715 patients encountered by the HEMS during the study period, 2053 patients were classified as having no long-term survival and included. At 30 days, 713 (35%, 95% CI 33% to 37%) were still alive and 69 were lost to follow-up. Furthermore, at 1 year 524 (26%) and at 3 years 267 (13%) of the patients were still alive. The deceased patients received more often prehospital rapid sequence intubation and vasoactives, compared with patients alive at 30 days. Patients deceased at 30 days were older and had lower initial Glasgow Coma Scores. Otherwise, no clinically relevant difference was found in the prehospital vital parameters between the survivors and non-survivors. CONCLUSIONS: The prognostication of long-term survival for critically ill patients by a prehospital critical care clinician seems to fulfil only moderately. A prognosis based on clinical judgement must be handled with a great degree of caution and decision on limitation of advanced care should be made cautiously.

Standardised data collection in prehospital critical care: a comparison of medical problem categories and discharge diagnoses.

BACKGROUND: Prehospital medical problem reporting is essential in the management of helicopter emergency medical services (HEMS) operations. The consensus-based template for reporting and documenting in physician-staffed prehospital services exists and the classification of medical problems presented in the template is widely used in research and quality improvement. However, validation of the reported prehospital medical problem is lacking. This study aimed to describe the in-hospital diagnoses, patient characteristics and medical interventions in different categories of medical problems. METHODS: This retrospective, observational registry study examined the 10 most common in-hospital International Statistical Classification of Disease (ICD-10) diagnoseswithin different prehospital medical problem categories, defined by the HEMS physician/paramedic immediately after the mission was completed. Data were gathered from a national HEMS quality registry and a national hospital discharge registry. Patient characteristics and medical interventions related to different medical problem categories are also described. RESULTS: A total of 33,844 patients were included in the analyses. All the medical problem categories included a broad spectrum of ICD-10 diagnoses (the number of diagnosis classes per medical problem category ranged from 73 to 403). The most frequent diagnoses were mainly consistent with the reported medical problems. Overlapping of ICD-10 diagnoses was mostly seen in two medical problem categories: stroke and acute neurology excluding stroke. Additionally, typical patient characteristics and disturbances in vital signs were related to adequate medical problem categories. CONCLUSIONS: Medical problems reported by HEMS personnel have adequate correspondence to hospital discharge diagnoses. However, the classification of cerebrovascular accidents remains challenging.

Effect of time intervals in critical care provided by helicopter emergency medical services on 30-day survival after trauma.

BACKGROUND: Trauma is the leading cause of death especially in children and young adults. Prehospital care following trauma emphasizes swift transport to a hospital following initial care. Previous studies have shown conflicting results regarding the effect of time on the survival following major trauma. In our study we investigated the effect of prehospital time-intervals on 30-day mortality on trauma patients that received prehospital critical care. METHODS: We performed a retrospective study on all trauma patients encountered by helicopter emergency medical services in Finland from 2012 to 2018. Patients discharge diagnoses were classed into (1) trauma without traumatic brain injury, (2) isolated traumatic brain injury and (3) trauma with traumatic brain injury. Emergency medical services response time, helicopter emergency medical services response time, on-scene time and transport time were used as time-intervals and age, Glasgow coma scale, hypotension, need for prehospital airway intervention and ICD-10 based Injury Severity Score were used as variables in logistic regression analysis. RESULTS: Mortality data was available for 4,803 trauma cases. The combined 30-day mortality was 12.1% (582/4,803). Patients with trauma without a traumatic brain injury had the lowest mortality, at 4.3% (111/2,605), whereas isolated traumatic brain injury had the highest, at 22.9% (435/1,903). Patients with both trauma and a traumatic brain injury had a mortality of 12.2% (36/295). Following adjustments, no association was observed between time intervals and 30-day mortality. DISCUSSION: Our study revealed no significant association between different timespans and mortality following severe trauma in general. Trends in odds ratios can be interpreted to favor more expedited care, however, no statistical significance was observed. As trauma forms a heterogenous patient group, specific subgroups might require different approaches regarding the prehospital timeframes. STUDY TYPE: prognostic/therapeutic/diagnostic test.

Short-term and long-term survival in critical patients treated by helicopter emergency medical services in Finland: a registry study of 36 715 patients.

OBJECTIVES: This study aimed to describe the short-term and long-term mortality of patients treated by prehospital critical care teams in Finland. DESIGN AND SETTING: We performed a registry-based retrospective study that included all helicopter emergency medical service (HEMS) dispatches in Finland from 1 January 2012 to 8 September 2019. Mortality data were acquired from the national Population Register Centre to calculate the standardised mortality ratio (SMR). PARTICIPANTS: All patients encountered by Finnish HEMS crews during the study period were included. MAIN OUTCOMES: Mortalities presented at 0 to 1 day, 2 to 30 days, 31 days to 1 year and 1 to 3 years for different medical reasons following the prehospital care. Patients were divided into four groups by age and categorised by gender. The SMR at 2 to 30 days, 31 days to 1 year and 1 to 3 years was calculated for the same groups. RESULTS: Prehospital critical care teams participated in the treatment of 36 715 patients, 34 370 of whom were included in the study. The cumulative all-cause mortality at 30 days was 27.5% and at 3 years was 36.5%. The SMR in different medical categories and periods ranged from 23.2 to 72.2, 18.1 to 22.4, 7.7 to 9.2 and 2.1 to 2.6 in the age groups of 0 to 17 years, 18 to 64 years, 65 to 79 years and ≥80 years, respectively. CONCLUSIONS: We found that the rate of mortality after a HEMS team provides critical care is high and remains significantly elevated compared with the normal population for years after the incident. The mortality is dependent on the medical reason for care and the age of the patient. The long-term overmortality should be considered when evaluating the benefit of prehospital critical care in the different patient groups.

Shock index as a predictor for short-term mortality in helicopter emergency medical services: A registry study.

BACKGROUND: The value of shock-index has been demonstrated in hospital triage, but few studies have evaluated its prehospital use. The aim of our study was to evaluate the association between shock-index in prehospital critical care and short-term mortality. METHODS: We analyzed data from the national helicopter emergency medical services database and the Population Register Centre. The shock-index was calculated from the patients' first measured parameters. The primary outcome measure was 1- and 30-day mortality. RESULTS: A total of 22 433 patients were included. The 1-day mortality was 7.5% and 30-day mortality was 16%. The median shock-index was 0.68 (0.55/0.84) for survivors and 0.67 (0.49/0.93) for non-survivors (P = .316) at 30-days. Association between shock-index and mortality followed a U-shaped curve in trauma (shock-index < 0.5: odds ratio 2.5 [95% confidence interval 1.8-3.4], shock-index > 1.3: odds ratio 4.4 [2.7-7.2] at 30 days). Patients with neurological emergencies with a low shock-index had an increased risk of mortality (shock-index < 0.5: odds ratio 1.8 [1.5-2.3]) whereas patients treated after successful resuscitation from out-of-hospital cardiac arrest, a higher shock-index was associated with higher mortality (shock-index > 1.3: odds ratio 3.5 [2.3-5.4). The association was similar for all ages, but older patients had higher mortality in each shock-index category. CONCLUSION: The shock-index is associated with short time mortality in most critical patient categories in the prehospital setting. However, the marked overlap of shock-index in survivors and non-survivors in all patient categories limits its predictive value.

The first seven years of nationally organized helicopter emergency medical services in Finland - the data from quality registry.

BACKGROUND: Helicopter Emergency Medical Services (HEMS) play an important role in prehospital care of the critically ill. Differences in funding, crew composition, dispatch criteria and mission profile make comparison between systems challenging. Several systems incorporate databases for quality control, performance evaluation and scientific purposes. FinnHEMS database was incorporated for such purposes following the national organization of HEMS in Finland 2012. The aims of this study are to describe information recorded in the database, data collection, and operational characteristics of Finnish HEMS during 2012-2018. METHODS: All dispatches of the six Finnish HEMS units recorded in the national database from 2012 to 2018 were included in this observational registry study. Five of the units are physician staffed, and all are on call 24/7. The database follows a template for uniform reporting in physician staffed pre-hospital services, exceeding the recommended variables of relevant guidelines. RESULTS: The study included 100,482 dispatches, resulting in 33,844 (34%) patient contacts. Variables were recorded with little or no missing data. A total of 16,045 patients (16%) were escorted by HEMS to hospital, of which 2239 (2%) by helicopter. Of encountered patients 4195 (4%) were declared deceased on scene. The number of denied or cancelled dispatches was 66,638 (66%). The majority of patients were male (21,185, 63%), and the median age was 57.7 years. The median American Society of Anesthesiologists Physical Scale classification was 2 and Eastern Cooperative Oncology Group performance class 0. The most common reason for response was trauma representing 26% (8897) of the patients, followed by out-of-hospital cardiac arrest 20% (6900), acute neurological reason excluding stroke 13% (4366) and intoxication and related psychiatric conditions 10% (3318). Blunt trauma (86%, 7653) predominated in the trauma classification. CONCLUSIONS: Gathering detailed and comprehensive data nationally on all HEMS missions is feasible. A national database provides valuable insights into where the operation of HEMS could be improved. We observed a high number of cancelled or denied missions and a low percentage of patients transported by helicopter. The medical problem of encountered patients also differs from comparable systems.

Point-of-care analyses of blood samples from intraosseous access in pre-hospital critical care.

BACKGROUND: Intraosseous (IO) access is used for fluid and medication administration in emergency situations when difficulties with vascular access are encountered. IO access would be readily available to take samples for point-of-care (POC) analysis, but there is scarce evidence about the reliability of POC analysis of IO samples among emergency patients. The aim of this study was to evaluate the feasibility and reliability of POC analysis of IO samples in critically ill pre-hospital patients. METHODS: We performed a prospective, observational study in 35 critically ill pre-hospital patients. After inserting a humeral IO needle, we immediately drew an IO sample. We compared the results to an arterial sample drawn from the same patient within 5 (blood gases) or 15 (other parameters) minutes. Samples were analysed with an i-STAT® POC analyser for blood gases, acid-base balance, electrolytes, glucose and haemoglobin. The agreement between each patient's IO and arterial samples was analysed using the Bland-Altman method. The results were compared to responses about acceptable bias on a questionnaire sent to 16 experienced emergency physicians. RESULTS: The analysis was successful for 23 patients (70%). Higher age was associated with failed analyses. The average bias was acceptable for base excess, pH, standard bicarbonate, glucose, ionized calcium and sodium. IO potassium values were systematically higher than arterial values. IO haemoglobin values had widely varying agreement. CONCLUSION: When vascular access is challenging, IO access can be used for emergency POC analyses to help guide clinical decision-making. However, the limitations of IO POC analyses must be carefully considered.

Epidemiology and aetiology of impaired level of consciousness in prehospital nontrauma patients in an urban setting.

BACKGROUND: There is little information on the epidemiology and aetiology of nontraumatic loss of consciousness in patients in the Emergency Department, and this high-risk patient group has been poorly characterized in the prehospital setting as well. The aim of this study was to study the epidemiology and aetiology of nontraumatic impaired level of consciousness among the patients treated by an urban Emergency Medical Service (EMS) system in Finland. METHODS: Data of all emergency calls not related to trauma in an urban EMS system in southern Finland during 2012 were analysed. The inclusion criterion in this study was impaired level of consciousness as identified from the EMS run sheets. Diagnoses made in the receiving facility were cross-checked with the data. RESULTS: During the study period, the EMS was alerted to 22 184 emergency calls. Of these, 306 calls met the inclusion criterion. The included patients could be categorized into four groups: seizures (32%), diabetes (24%), intoxication (17%) and impaired level of consciousness with no other obvious or specific cause (27%). The overall case fatality rate was 8%. CONCLUSION: Of all EMS calls, patients who presented with an impaired level of consciousness represented 1.4% of all patients, but the fatality rate in those who remained with an impaired level of consciousness during the prehospital phase was considerable. Impaired level of consciousness was associated with a multitude of aetiologies, of which seizures were the most common.