Helicopter Medical Services Research Articles

Operability of a Resonance-Based Viscoelastic Haemostatic Analyzer in the High-Vibration Environment of Air Medical Transport.

Trauma and bleeding are associated with a high mortality, and most of these deaths occur early after injury. Viscoelastic haemostatic tests have gained increasing importance in goal-directed transfusion and bleeding management. A new generation of small-sized and thus portable ultrasound-based viscoelastic analysers have been introduced in clinical practice. We questioned whether a promising candidate can be used in emergency helicopters, with a focus on the susceptibility to vibration stress. We investigated whether the high vibration environment of an emergency helicopter would affect the operability of an ultrasound-based viscoelastic analyser and would yield reproducible results in flight and on the ground. We drew blood from 27 healthy volunteers and performed simultaneous analyses on two TEG 6s. Each measurement was performed in-flight on board an Airbus H135 emergency helicopter and was repeated on the ground, close to the flight area. Results from both measurements were compared, and the recorded tracings and numeric results were analysed for artifacts. Vibratometric measurements were performed throughout the flight in order to quantify changes in the magnitude and character of vibrations in different phases of helicopter operation. The high vibration environment was associated with the presence of artifacts in all recorded tracings. There were significant differences in citrated Kaolin + Heparinase measurements in-flight and on the ground. All other assays increased in variability but did not show significant differences between the two time points. We observed numerous artifacts in viscoelastic measurements that were performed in flight. Some parameters that were obtained from the same sample showed significant differences between in-flight and on-ground measurements. Performing resonance-based viscoelastic tests in helicopter medical service is prone to artifacts. However, a 10 min delay between initiation of measurement and take-off might produce more reliable results.

Acute medical missions by helicopter medical service (HEMS) to municipalities with different approach for primary care physicians.

BackgroundThe prehospital emergency system in Norway involves out-of-hours (OOH) services with on-call physicians. Helicopter emergency medical service (HEMS) are used in cases of severe illness or trauma that require rapid transport and/or an anesthesiologist’s services. In recent years, on-call primary care physicians have been less available for call-outs in Norway, and HEMS may be requested for missions that could be adequately handled by on-call physicians. Here, we investigated how different availability of an on-call physician to attend emergency patients at site (call-out) impacted requests and use of HEMS.MethodsOur analysis included all acute medical missions in an urban and nearby rural OOH district, which had different approach regarding physician call-outs from the OOH service. For this prospective observational study, we used data from both HEMS and the OOH service from November 1st 2017 until November 30th 2018. Standard descriptive statistical analyses were used.ResultsThe rates of acute medical missions in the urban and rural OOH districts were similar (30 and 29 per 1000 inhabitants per year, respectively). The rate of HEMS requests was significantly higher in the rural OOH district than in the urban district (2.4 vs. 1.7 per 1000 inhabitants per year, respectively). Cardiac arrest and trauma were the major symptom categories in more than one half of the HEMS-attended patients, in both districts. Chest pain was the most frequent reason for an OOH call-out in the rural OOH district (21.1%). An estimated NACA score of 5–7 was found in 47.7% of HEMS patients from the urban district, in 40.0% of HEMS patients from the rural OOH district (p = 0.44), and 12.8% of patients attended by an on-call physician in the rural OOH district (p < 0.001). Advanced interventions were provided by an anesthesiologist to one-third of the patients attended by HEMS, of whom a majority had an NACA score of ≥ 5.ConclusionsHEMS use did not differ between the two compared areas, but the rate of HEMS requests was significantly higher in the rural OOH district. The threshold for HEMS use seems to be independent of on-call primary care physician involvement.

An analysis of prehospital critical care events and management patterns from 97 539 emergency helicopter medical service missions: A retrospective registry-based study.

It is largely unknown how often physicians in emergency helicopter medical services (HEMS) encounter various critical care events and if HEMS exposure is associated with particular practice patterns or outcomes. This study aimed: to describe the frequency and distribution of critical care events; to investigate whether HEMS exposure is associated with differences in practice patterns and determine if HEMS exposure factors are associated with mortality. A retrospective registry-based study. Physician-staffed HEMS in Finland between January 2012 and August 2019. Ninety-four physicians who worked at least 6 months in the HEMS during the study period. Physicians with undeterminable HEMS exposure were excluded from practice pattern comparisons and mortality analysis, leaving 80 physicians. The primary outcome measure was a physician's average annual frequencies for operational events and clinical interventions. Our secondary outcomes were the proportion of missions cancelled or denied, time onsite (OST) and proportion of unconscious patients intubated. Our tertiary outcome was adjusted 30-day mortality of patients. The physicians encountered 62 [33 to 98], escorted 31 [17 to 41] and transported by helicopter 2.1 [1.3 to 3.5] patients annually, given as median [interquartile range; IQR]. Rapid sequence intubation was performed 11 [6.2 to 16] times per year. Physicians were involved in out-of-hospital cardiac arrest (OHCA) 10 [5.9 to 14] and postresuscitation care 5.5 [3.1 to 8.1] times per year. Physicians with longer patient intervals had shorter times onsite. Proportionally, they cancelled more missions and intubated fewer unconscious patients. A short patient interval [odds ratio (OR); 95% confidence interval (CI)] was associated with decreased mortality (0.87; 95% CI, 0.76 to1.00), whereas no association was observed between mortality and HEMS career length. Prehospital exposure is distributed unevenly, and some physicians receive limited exposure to prehospital critical care. This seems to be associated with differences in practice patterns. Rare HEMS patient contacts may be associated with increased mortality.

Endovascular Treatment of Acute Ischemic Stroke.

Endovascular thrombectomy (ET), the standard of treatment for emergent large vessel occlusion (ELVO) strokes, has been subject to rigorous efforts to further improve its usage and delivery for optimised patient outcomes. This review aims to provide an outline and discussion about the recently established and emerging recommendations regarding endovascular treatment of stroke. The indications for ET have expanded continually, with perfusion imaging now enabling selection of patients presenting 6-24h after last-known-well, and improved device and operator proficiency allowing treatment of M2-MCA occlusions and tandem occlusions. Further inclusion of paediatric patients and patients with larger infarct core or milder stroke symptoms for ET has been proposed; however, this remains unproven. This growing applicability is supported by more efficient systems of care, employing modern techniques such as telemedicine, mobile stroke units and helicopter medical services. Ongoing debate exists regarding thrombolytic agent, thrombectomy technique, anaesthesia method and the role of advanced neuroimaging, with upcoming RCTs expected to provide clarification. The journey to further improving the efficacy of ET has advanced and diversified rapidly over recent years, involving improved patient selection, increased utility of advanced neuroimaging and ongoing device redevelopment, within the setting of more efficient, streamlined systems of care. This dynamic and ongoing influx of evidence-based refinements is key to further optimising outcomes for ELVO patients.

The deployment of a Helicopter Emergency Medical Service for vitally compromised children in the Netherlands

Objective: To evaluate the deployment of a Helicopter Medical Service (HEMS) for vitally compromised children in an HEMS region. A comparison is made between HEMS deployment for children and adults, with a subsequent evaluation of the current HEMS deployment criteria for vitally compromised children. Methods: Prospective descriptive cohort analysis of all HEMS calls for paediatric emergencies (age 0-18 years) in the period 2001-2008. Data regarding type and location of incident, physiological parameters, Munich-modified NACA scores, treatment and 24-hour survival were collected and subsequently analysed.Results: The HEMS had 891 calls for paediatric emergencies in the period from 2001-2008. Twenty-seven percent of these calls were cancelled before the arrival of the HEMS, while 48% of the calls for adults were cancelled. The cancel percentage of all HEMS calls increased significantly over the years; the cancel percentage of HEMS calls for children remained at a steady state. The HEMS coordinating dispatch region had a significant higher percentage of low NACA scores in comparison to the other dispatch regions. The non-trauma incidents had the lowest 24-hour survival rate, the highest 24-hour survival rate was in the incident group of HEMS calls based on mechanism of injury.Conclusion: Dispatch criteria used for HEMS in the Netherlands appear not to be well suited to children and should be adjusted to contain a score of the neurological status. Dispatch criteria based on mechanism of injury are a poor triage tool, several types of severe illness should be explicitly included. Cancel criteria for HEMS calls in children are not applied in a consistent manner, and should be revised.

Helicopter emergency medical service in the Republic of Croatia

Current situation of emergency medical assistance indi­ cates the need to organize faster and more efficient system of linking all the parts of the Republic of Croatia. The solution can be found in the implementation of aviation as the fastest and therefore the best method of transporting the injured, dis­ eased and other persons who need urgent transpmt. The use of military helicopters for the purposes of emergency aviation does not satisfy the needs of the Republic of Croatia from the organi­ zational and legal aspect. There were 597 fatalities on the Cro­ atian roads in 2005 and with the establishment of emergency helicopter medical service, the number of fatalities may be re­ duced by one third.