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.

Multifaceted implementation and sustainability of a protocol for prehospital anaesthesia: a retrospective analysis of 2115 patients from helicopter emergency medical services.

BACKGROUND: Prehospital emergency anaesthesia (PHEA) is a high-risk procedure. We developed a prehospital anaesthesia protocol for helicopter emergency medical services (HEMS) that standardises the process and involves ambulance crews as active team members to increase efficiency and patient safety. The aim of the current study was to evaluate this change and its sustainability in (i) on-scene time, (ii) intubation first-pass success rate, and (iii) protocol compliance after a multifaceted implementation process. METHODS: The protocol was implemented in 2015 in a HEMS unit and collaborating emergency medical service systems. The implementation comprised dissemination of information, lectures, simulations, skill stations, academic detailing, and cognitive aids. The methods were tailored based on implementation science frameworks. Data from missions were gathered from mission databases and patient records. RESULTS: During the study period (2012-2020), 2381 adults underwent PHEA. The implementation year was excluded; 656 patients were analysed before and 1459 patients after implementation of the protocol. Baseline characteristics and patient categories were similar. On-scene time was significantly redused after the implementation (median 32 [IQR 25-42] vs. 29 [IQR 21-39] minutes, p < 0.001). First pass success rate increased constantly during the follow-up period from 74.4% (95% CI 70.7-77.8%) to 97.6% (95% CI 96.7-98.3%), p = 0.0001. Use of mechanical ventilation increased from 70.6% (95% CI 67.0-73.9%) to 93.4% (95% CI 92.3-94.8%), p = 0.0001, and use of rocuronium increased from 86.4% (95% CI 83.6-88.9%) to 98.5% (95% CI 97.7-99.0%), respectively. Deterioration in compliance indicators was not observed. CONCLUSIONS: We concluded that clinical performance in PHEA can be significantly improved through multifaceted implementation strategies.

Association between physician's case volume in prehospital advanced trauma care and 30-day mortality: A registry-based analysis of 4,032 patients.

BACKGROUND: Seriously injured patients may benefit from prehospital interventions provided by a critical care physician. The relationship between case volume and outcome has been established in trauma teams in hospitals, as well as in prehospital advanced airway management. In this study, we aimed to assess if a volume-outcome relationship exists in prehospital advanced trauma care. METHODS: We performed a retrospective cohort study using the national helicopter emergency medical services database, including trauma patients escorted from scene to hospital by a helicopter emergency medical services physician during January 1, 2013, to August 31, 2019. In addition, similar cases during 2012 were used to determine case volumes. We performed a multivariate logistic regression analysis, with 30-day mortality as the outcome. Age, sex, Glasgow Coma Scale, shock index, mechanism of injury, time interval from alarm to the patient and duration of transport, level of receiving hospital, and physician's trauma case volume were used as covariates. On-scene times, interventions performed, and status at hospital arrival were assessed in patients who were grouped according to physician's case volume. RESULTS: In total, 4,032 escorted trauma patients were included in the study. The median age was 40.2 (22.9-59.3) years, and 3,032 (75.2%) were male. Within 30 days, 498 (13.2%) of these patients had died. In the highest case volume group, advanced interventions were performed more often, and patients were less often hypotensive at handover. Data for multivariate analysis were available for 3,167 (78.5%) of the patients. Higher case volume was independently associated with lower mortality (odds ratio, 0.59; 95% confidence interval, 0.38-0.89). CONCLUSION: When a prehospital physician's case volume is higher in high-risk prehospital trauma, this seems to be associated with more active practice patterns and significantly lower 30-day mortality. The quality of prehospital critical care could be increased by ensuring sufficient case volume for the providers of such care. LEVEL OF EVIDENCE: Prognostic and Epidemiologic; Level III.

Cerebral oxygen desaturation events during and functional outcomes after prehospital anaesthesia: A prospective pilot study.

BACKGROUND: During prehospital anaesthesia, oxygen delivery to the brain might be inadequate to match the oxygen consumption, with unknown long-term functional outcomes. We aimed to evaluate the feasibility of monitoring cerebral oxygenation during prehospital anaesthesia and determining the long-term outcomes. METHODS: We performed a prospective observational feasibility study in two helicopter emergency medical services units. Frontal lobe regional oxygen saturation (rSO2 ) of adult patients undergoing prehospital anaesthesia was monitored with near-infrared spectroscopy (NIRS) by a Nonin H500 oximeter. The outcome was evaluated with a modified Rankin Scale (mRS) at 30 days and 1 year. Health-related quality of life (HRQoL) was measured with a 15D instrument at 1 year. RESULTS: Of 101 patients enrolled, 83 were included. The mean baseline rSO2 was 79% (73-84). Desaturation for at least 5 min to rSO2 below 50% or a decrease of 10% from baseline occurred in four (5%, 95% CI 2%-12%) and 19 (23%, 95% CI 15-93) patients. At 1 year, 32 patients (53%, 95% CI 41-65) achieved favourable neurological outcomes. The median 15D score was 0.889 (Q1-Q3, 0.796-0.970). CONCLUSION: Monitoring cerebral oxygenation with a hand-held oximeter during prehospital anaesthesia and collecting data on functional outcomes and HRQoL are feasible. Only half of the patients achieved a favourable functional outcome. The effects of cerebral oxygenation on outcomes during prehospital critical care need to be assessed in future studies.

Association between case volume and mortality in pre-hospital anaesthesia management: a retrospective observational cohort.

BACKGROUND: Pre-hospital anaesthesia is a core competency of helicopter emergency medical services (HEMS). Whether physician pre-hospital anaesthesia case volume affects outcomes is unknown in this setting. We aimed to investigate whether physician case volume was associated with differences in mortality or medical management. METHODS: We conducted a registry-based cohort study of patients undergoing drug-facilitated intubation by HEMS physician from January 1, 2013 to August 31, 2019. The primary outcome was 30-day mortality, analysed using multivariate logistic regression controlling for patient-dependent variables. Case volume for each patient was determined by the number of pre-hospital anaesthetics the attending physician had managed in the previous 12 months. The explanatory variable was physician case volume grouped by low (0-12), intermediate (13-36), and high (≥37) case volume. Secondary outcomes were characteristics of medical management, including the incidence of hypoxaemia and hypotension. RESULTS: In 4818 patients, the physician case volume was 511, 2033, and 2274 patients in low-, intermediate-, and high-case-volume groups, respectively. Higher physician case volume was associated with lower 30-day mortality (odds ratio 0.79 per logarithmic number of cases [95% confidence interval: 0.64-0.98]). High-volume physician providers had shorter on-scene times (median 28 [25th-75th percentile: 22-38], compared with intermediate 32 [23-42] and lowest 32 [23-43] case-volume groups; P<0.001) and a higher first-pass success rate for tracheal intubation (98%, compared with 93% and 90%, respectively; P<0.001). The incidence of hypoxaemia and hypotension was similar between groups. CONCLUSIONS: Mortality appears to be lower after pre-hospital anaesthesia when delivered by physician providers with higher case volumes.

Characteristics of Nontrauma Patients Receiving Prehospital Blood Transfusion with the Same Triggers as Trauma Patients: A Retrospective Observational Cohort Study.

Objective: While prehospital blood transfusion (PHBT) for trauma patients has been established in many services, the literature on PHBT use for nontrauma patients is limited. We aimed to describe and compare nontrauma and trauma patients receiving PHBT who had similar hemodynamic triggers. Methods: We analyzed 3.5 years of registry data from a single prehospital critical care unit. The PHBT protocol included two packed red blood cell units and was later completed with two freeze-dried plasma units. The transfusion triggers were a strong clinical suspicion of massive hemorrhage and systolic blood pressure below 90 mmHg or absent radial pulse. Results: Thirty-six nontrauma patients and 96 trauma patients received PHBT. The nontrauma group had elderly patients (median 65 [interquartile range, IQR, 56-73] vs 37 [IQR 25-57] years, p < 0.0001) and included patients with gastrointestinal bleeding (n = 15; 42%), vascular catastrophes (n = 9; 25%), postoperative bleeding (n = 6; 17%), obstetrical bleeding (n = 4; 11%) and other (n = 2; 6%). Cardiac arrest occurred in nine (25%) nontrauma and in 15 (16%) trauma patients. Of these, 5 (56%) and 10 (67%) survived to hospital admission and 3 (33%) and 2 (13%) to hospital discharge. On admission, the nontrauma patients had lower hemoglobin (median 95 [84-119] vs 124 [108-133], p < 0.0001), higher pH (median 7.40 [7.27-7.44] vs 7.30 [7.19-7.36], p = 0.0015) and lower plasma thromboplastin time (median 55 [45-81] vs 72 [58-86], p = 0.0261) than the trauma patients. Conclusions: We identified four nontrauma patient groups in need of PHBT, and the patients appeared to be seriously ill. Efficacy of prehospital transfusion in nontrauma patients should be evaluated futher in becoming studies.

Arterial and end-tidal carbon dioxide partial pressure difference during prehospital anaesthesia in critically ill patients.

BACKGROUND: Normoventilation is crucial for many critically ill patients. Ventilation is routinely guided by end-tidal capnography during prehospital anaesthesia, based on the assumption of the gap between arterial partial pressure of carbon dioxide (PaCO2 ) and end-tidal carbon dioxide partial pressure (PetCO2 ) of approximately 0.5 kPa (3.8 mmHg). METHODS: We retrospectively analysed the airway registry and patient chart data of patients who had been anaesthetised and intubated endotracheally by the prehospital critical care team and had their prehospital arterial blood gases analysed. Bland-Altman analysis was used to estimate the bias and limits of agreement. RESULTS: Altogether 502 patients were included in the study, with a median age of 58 years. The most common patient groups were post-resuscitation (155, 31%), neurological emergencies (96, 19%), intoxication (75, 15%) and trauma (68, 14%). The median of the gap between PaCO2 and PetCO2 was 1.3 kPa (interquartile range 0.7 to 2.2) (9.8 (5.3-16.5) mmHg). Mean bias of PetCO2 was -1.6 kPa/12.0 mmHg (standard deviation 1.7 kPa/12.8 mmHg) with 95% confidence limits of agreement -4.9 to 1.9 kPa (-36.8 to 14.3 mmHg). The gap was ≥ 1.0 kPa (>7.5 mmHg) in 297 (66%, 95% confidence interval 55 to 63) patients. CONCLUSION: Our results suggest that end-tidal capnography alone might not be an adequate method to achieve normoventilation for critically ill patients intubated and mechanically ventilated in prehospital setting. Thus, an arterial blood gas analysis might be useful to recognize patients with an increased gap between PaCO2 and PetCO2 .

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.

A potential method of identifying stroke and other intracranial lesions in a prehospital setting.

BACKGROUND: Identifying stroke and other intracranial lesions in patients with a decreased level of consciousness may be challenging in prehospital settings. Our objective was to investigate whether the combination of systolic blood pressure, heart rate and age could be used to identify intracranial lesions. METHODS: We conducted a retrospective case-control study including patients with a decreased level of consciousness who had their airway secured during prehospital care. Patients with intracranial lesions were identified based on the final diagnoses at the end of hospitalization. We investigated the ability of systolic blood pressure, heart rate and age to identify intracranial lesions and derived a decision instrument. RESULTS: Of 425 patients, 127 had an intracranial lesion. Patients with a lesion were characterized by higher systolic blood pressure, lower heart rate and higher age (P < 0.0001 for all). A systolic blood pressure ≥ 140 mmHg had an odds ratio (OR) of 3.5 (95% confidence interval [CI] 1.7 to 7.0), and > 170 mmHg had an OR of 8.2 (95% CI 4.5-15.32) for an intracranial lesion (reference: < 140 mmHg). A heart rate < 100 beats/min had an OR of 3.4 (95% CI 2.0 to 6.0, reference: ≥100). Age 50-70 had an OR of 4.1 (95% CI 2.0 to 9.0), and > 70 years had an OR of 10.2 (95% CI 4.8 to 23.2), reference: < 50. Logarithms of ORs were rounded to the nearest integer to create a score with 0-2 points for age and blood pressure and 0-1 for heart rate, with an increasing risk for an intracranial lesion with higher scores. The area under the receiver operating characteristics curve for the instrument was 0.810 (95% CI 0.850-0.890). CONCLUSIONS: An instrument combining systolic blood pressure, heart rate and age may help identify stroke and other intracranial lesions in patients with a decreased level of consciousness in prehospital settings. TRIAL REGISTRATION: Not applicable.

Delayed return of spontaneous circulation (the Lazarus phenomenon) after cessation of out-of-hospital cardiopulmonary resuscitation.

INTRODUCTION: The delayed return of spontaneous circulation (ROSC) after cessation of cardiopulmonary resuscitation (CPR), also known as the Lazarus phenomenon, is a rare event described in several case reports. This study aims to determine the incidence and the time of occurrence of the Lazarus phenomenon after cessation of out-of-hospital CPR. METHODS: This prospective observational cohort study was conducted in the Helsinki Emergency Medical Service in Finland from 1 January 2011 through 31 December 2016. All out-of-hospital CPR attempts were carefully monitored for 10min after the cessation of CPR in order to detect delayed ROSC. RESULTS: Altogether, 2102 out-of-hospital cardiac arrests occurred during the six-year study period. CPR was attempted in 1376 (65.5%) cases. In 840 cases (61.0% of all attempts) CPR attempts were terminated on site. The Lazarus phenomenon occurred five times, with an incidence of 5.95/1000 (95% CI 2.10-14.30) in field-terminated CPR attempts. Time to delayed ROSC from the cessation of CPR varied from 3 to 8min. Three of the five patients with delayed ROSC died at the scene within 2-15min while two died later in hospital within 1.5 and 26h, respectively. CONCLUSIONS: We observed that the Lazarus phenomenon is a real albeit rare event and can occur a few minutes after the cessation of out-of-hospital CPR. We suggest a 10-min monitoring period before diagnosing death. CPR guidelines should be updated to include information of the Lazarus phenomenon and appropriate monitoring for it.

Prehospital Care of Burn Patients and Trajectories on Survival.

We sought to identify factors associated with the prognosis and survival of burn patients by analyzing data related to the prehospital treatment of burn patients transferred directly to the burn unit from the accident site. We also aimed to assess the role of prehospital physicians and paramedics providing care to major burn patients. This study included adult burn patients with severe burns treated between 2006 and 2010. Prehospital patient records and clinical data collected during treatment were analyzed, and the Injury Severity Scale (ISS) was calculated. Patients were grouped into two cohorts based on the presence or absence of a physician during the prehospital phase. Data were analyzed with reference to survival by multivariable regression model. Specific inclusion criteria resulted in a sample of 67 patients. The groups were comparable with regard to age, gender, and injury etiology. Patients treated by prehospital physicians (group 1, n = 49) were more severely injured than patients treated by paramedics (group 2, n = 18) in terms of total burn surface area (%TBSA) (32% vs. 17%, p = 0.033), ISS (25 vs. 8, p < 0.000), and inhalation injuries (51% vs. 16%, p = 0.013), and presented with a higher pulse rate, lower systolic blood pressure, and lower median pH. Age, gender, %TBSA, and ISS were significantly associated with survival in both groups. Survival at 30 days was associated with age, gender, the amount of intravenous fluids (in liters) received during the first 24 hours, and the final %TBSA. Variables found to be independently associated by multivariable regression model with 30 day mortality were age, female gender, and final TBSA. We identified prehospital prognostic factors affecting patient outcomes. Based on the results from this study, our current EMS system is capable of identifying seriously injured burn patients who may benefit from physician attendance at the injury scene.

Paramedics' and pre-hospital physicians' assessments of anatomic injury in trauma patients: a cohort study.

BACKGROUND: The pre-hospital assessment of a blunt trauma is difficult. Common triage tools are the mechanism of injury (MOI), vital signs, and anatomic injury (AI). Compared to the other tools, the clinical assessment of anatomic injury is more subjective than the others, and, hence, more dependent on the skills of the personnel.The aim of the study was to estimate whether the training and qualifications of the personnel are associated with the accuracy of prediction of anatomic injury and the completion of pre-hospital procedures indicated by local guidelines. METHODS: Adult trauma patients met by a trauma team at Helsinki University Trauma Centre during a 12-month period (n = 422) were retrospectively analysed. To evaluate the accuracy of prediction of anatomic injury, clinically assessed pre-hospital injuries in six body regions were compared to injuries assessed at hospital in two patient groups, the patients treated by pre-hospital physicians (group 1, n = 230) and those treated by paramedics (group 2, n = 190). RESULTS: The groups were comparable in respect to age, sex, and MOI, but the patients treated by physicians were more severely injured than those treated by paramedics [ISS median (interquartile range) 16 (6-26) vs. 6 (2-10)], thus rendering direct comparison of the groups ineligible. The positive predictive values (95% confidence interval) of assessed injury were highest in head injury [0,91 (0,84-0,95) in group 1 and 0,86 (0,77-0,92) in group 2]. The negative predictive values were highest in abdominal injury [0,85 (0,79-0,89) in group 1 and 0,90 (0,84-0,93) in group 2]. The measurements of agreement between injuries assessed pre- and in-hospitally were moderate in thoracic and extremity injuries. Substantial kappa values (95% confidence interval) were achieved in head injury, 0,67 (0,57-0,77) in group 1 and 0,63 (0,52-0,74) in group 2. The rate of performing the pre-hospital procedures as indicated by the local instructions was 95-99%, except for decompression of tension pneumothorax. CONCLUSION: Accurate prediction of anatomic injury is challenging. No conclusive differences were seen in the ability of pre-hospital physicians and paramedics to predict anatomic injury in the respective patient populations.

Adherence to resuscitation guidelines during prehospital care of cardiac arrest patients.

OBJECTIVE: The impact of prehospital care after the return of spontaneous circulation in out-of-hospital cardiac arrest patients is not known. This study describes adherence to the resuscitation guidelines, factors associated with poor adherence and possible impact of prehospital postresuscitation care on the outcome of out-of-hospital cardiac arrest. METHODS: One hundred and fifty-seven Finnish out-of-hospital cardiac arrest patients hospitalized during 1 year, were analyzed retrospectively. Patient and arrest characteristics, prehospital postresuscitation care and survival to hospital discharge were analyzed using multivariate logistic regression. RESULTS: Forty percent of the patients received care accordant with the guidelines. Male sex (P=0.045), witnessed arrest (P=0.031), initial ventricular fibrillation/ventricular tachycardia rhythm (P=0.007) and the presence of an emergency physician (P=0.017) were associated with care in line with the current guidelines. In multivariate logistic regression analysis, age over median (odds ratio=3.6, 95% confidence interval 1.5-8.6), nonventricular fibrillation/ventricular tachycardia initial rhythm (odds ratio=4.0, 95% confidence interval 1.6-9.8), administration of adrenaline (odds ratio=7.0, 95% confidence interval 2.3-21.4) and unsatisfactory prehospital postresuscitation care (odds ratio=2.5, 95% confidence interval 1.1-6.3) were associated with a failure to survive up to hospital discharge. CONCLUSIONS: Less than 50% of out-of-hospital cardiac arrest patients received prehospital postresuscitation care compatible with the current guidelines. Markers of poor prognosis were associated with unsatisfactory care, which in turn was more frequent among the patients who did not survive to hospital discharge. The importance of the guidelines should be highlighted in the future.