Experiences from a cluster-randomized trial (ParaNASPP) exploring triage and diagnostic accuracy in paramedic-suspected stroke: a qualitative interview study

BACKGROUND AND PURPOSE

Timely prehospital stroke recognition was explored in the Paramedic Norwegian Acute Stroke Prehospital Project (ParaNASPP) by implementation of stroke education for paramedics and use of the National Institutes of Health Stroke Scale (NIHSS) through a mobile application. The study tested triage and facilitated communication between paramedics and stroke physicians. To complement the quantitative results of the clinical trial, a qualitative approach was used to identify factors that influence triage decisions and diagnostic accuracy in prehospital stroke recognition experienced by paramedics and stroke physicians.

METHOD

Semi-structured qualitative individual interviews were performed following an interview guide. Informants were recruited from the enrolled paramedics and stroke physicians who participated in the ParaNASPP trial from Oslo University Hospital. Interviews were audio recorded, transcribed verbatim and approached inductively using the principles of thematic analysis.

RESULTS

Fourteen interviews were conducted, with seven paramedics and seven stroke physicians. Across both groups two overarching themes were identified related to triage decisions and diagnostic accuracy in prehospital stroke recognition: prehospital NIHSS reliably improves clinical assessment and communication quality; overtriage is widely accepted whilst undertriage is not.

CONCLUSION

Paramedics and stroke physicians described how prehospital NIHSS improved communication quality and reliably improved prehospital clinical assessment. The qualitative results support a rationale of an application algorithm to decide which NIHSS items should prompt immediate prenotification rather than a complete NIHSS as default.

Can video communication in the emergency medical communication centre improve dispatch precision? A before-after study in Norwegian helicopter emergency medical services

OBJECTIVES

Dispatching helicopter emergency medical services (HEMS) to the patients with the greatest medical or logistical benefit remains challenging. The introduction of video calls (VC) in the emergency medical communication centres (EMCC) could provide additional information for EMCC operators and HEMS physicians when assessing the need for HEMS dispatch. The aim of this study was to evaluate the impact from VC in the EMCC on HEMS dispatch precision.

DESIGN

An observational before-after study.

SETTING

The regional EMCC and one HEMS base in Mid-Norway.

PARTICIPANTS

EMCC operators and HEMS physicians at the EMCC and HEMS base in Trondheim, Norway.

INTERVENTION

In January 2022, VC became available in emergency calls in Trondheim EMCC. Data were collected from 2020 2021 (pre-intervention) and 2022 (post-intervention).

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the proportion of seriously ill or injured HEMS patients, defined as a National Advisory Committee for Aeronautics (NACA) score between 4 and 7. The secondary outcome was the proportion of inappropriate dispatches, defined as missions with neither provision of additional competence nor any logistical contribution based on quality indicators for physician-staffed emergency medical services.

RESULTS

811 and 402 HEMS missions with patient contact were included in the pre- and post-intervention group, respectively. The proportion of missions with NACA 4-7 was not significantly changed after the intervention (OR 1.21, 95% CI 0.92 to 1.61, p=0.17). There was no significant change in HEMS alarm times between the pre- and post-intervention groups (7.6 min vs 6.4 min, p=0.15). The proportion of missions with neither medical nor logistical benefit was significantly lower in the post-intervention group (28.4% vs 40.3%, p=0.007).

CONCLUSION

The results from this study indicate that VC is a promising, feasible and safe tool for EMCC operators in the complex HEMS dispatch process.

Feasibility of prehospital identification of non-ST-elevation myocardial infarction by ECG, troponin and echocardiography

Background

Prehospital identification and selection of treatment strategy in patients with suspected non-ST-elevation myocardial infarction (NSTEMI) is challenging. The aim of this study was to evaluate the feasibility and diagnostic accuracy of prehospital ECG, troponin T (TnT) and transthoracic echocardiography (TTE) acquired by paramedics in early identification of NSTEMI.

Methods

Consecutive patients requesting an ambulance from Sorlandet Hospital, Norway due to chest pain between November 2017 and January 2020 were screened for inclusion in the study. One ambulance was equipped with ECG recorder, point-of-care TnT test and TTE scanner, and six paramedics were given necessary training. ECG, TnT result and TTE images were acquired prehospitally and transferred to an in-hospital cardiologist. NSTEMI was suspected in patients with ischaemic ECG changes, elevated TnT or myocardial regional wall motion abnormalities (RWMA) at TTE.

Results

A total of 253 patients were included in the study. ECG was interpretable by cardiologists in 243 (96%), TnT in 238 (94%) and TTE images in 240 (95%) patients. NSTEMI was the discharge diagnosis in 22 (9%) of these patients. Four (18%) patients with NSTEMI had ischaemic ECG changes, elevated TnT and RWMA at TTE. Eight (36%) patients with NSTEMI had positive findings at two of the diagnostic methods, six (27%) patients had positive findings at one, and four (18%) patients had no positive findings in any of the diagnostic methods. In three patients (14%) with NSTEMI, RWMA was the only positive test. The negative and positive predictive values for RWMA were 42% and 96%, respectively.

Conclusions

Prehospital acquisition of ECG, TnT and interpretable TTE images by paramedics were feasible in most patients with chest pain. Based on these examinations, it was possible to identify the majority of cases with NSTEMI prehospitally and admit the patients directly to a hospital with facilities for percutaneous coronary intervention (PCI) for further treatment.

Trial registration number

NCT04223986.

Testing quality indicators and proposing benchmarks for physician-staffed emergency medical services: a prospective Nordic multicentre study

OBJECTIVES

A consensus study from 2017 developed 15 response-specific quality indicators (QIs) for physician-staffed emergency medical services (P-EMS). The aim of this study was to test these QIs for important characteristics in a real clinical setting. These characteristics were feasibility, rankability, variability, actionability and documentation. We further aimed to propose benchmarks for future quality measurements in P-EMS.

DESIGN

In this prospective observational study, physician-staffed helicopter emergency services registered data for the 15 QIs. The feasibility of the QIs was assessed based on the comments of the recording physicians. The other four QI characteristics were assessed by the authors. Benchmarks were proposed based on the quartiles in the dataset.

SETTING

Nordic physician-staffed helicopter emergency medical services.

PARTICIPANTS

16 physician-staffed helicopter emergency services in Finland, Sweden, Denmark and Norway.

RESULTS

The dataset consists of 5638 requests to the participating P-EMSs. There were 2814 requests resulting in completed responses with patient contact. All QIs were feasible to obtain. The variability of 14 out of 15 QIs was adequate. Rankability was adequate for all QIs. Actionability was assessed as being adequate for 10 QIs. Documentation was adequate for 14 QIs. Benchmarks for all QIs were proposed.

CONCLUSIONS

All 15 QIs seem possible to use in everyday quality measurement and improvement. However, it seems reasonable to not analyse the QI 'Adverse Events' with a strictly quantitative approach because of a low rate of adverse events. Rather, this QI should be used to identify adverse events so that they can be analysed as sentinel events. The actionability of the QIs 'Able to respond immediately when alarmed', 'Time to arrival of P-EMS', 'Time to preferred destination', 'Provision of advanced treatment' and 'Significant logistical contribution' was assessed as being poor. Benchmarks for the QIs and a total quality score are proposed for future quality measurements.

Respiratory variations in pulse pressure and photoplethysmographic waveform amplitude during positive expiratory pressure and continuous positive airway pressure in a model of progressive hypovolemia

PURPOSE

Respiratory variations in pulse pressure (dPP) and photoplethysmographic waveform amplitude (dPOP) are used for evaluation of volume status in mechanically ventilated patients. Amplification of intrathoracic pressure changes may enable their use also during spontaneous breathing. We investigated the association between the degree of hypovolemia and dPP and dPOP at different levels of two commonly applied clinical interventions; positive expiratory pressure (PEP) and continuous positive airway pressure (CPAP).

METHODS

20 healthy volunteers were exposed to progressive hypovolemia by lower body negative pressure (LBNP). PEP of 0 (baseline), 5 and 10 cmH2O was applied by an expiratory resistor and CPAP of 0 (baseline), 5 and 10 cmH2O by a facemask. dPP was obtained non-invasively with the volume clamp method and dPOP from a pulse oximeter. Central venous pressure was measured in 10 subjects. Associations between changes were examined using linear mixed-effects regression models.

RESULTS

dPP increased with progressive LBNP at all levels of PEP and CPAP. The LBNP-induced increase in dPP was amplified by PEP 10 cmH20. dPOP increased with progressive LBNP during PEP 5 and PEP 10, and during all levels of CPAP. There was no additional effect of the level of PEP or CPAP on dPOP. Progressive hypovolemia and increasing levels of PEP were reflected by increasing respiratory variations in CVP.

CONCLUSION

dPP and dPOP reflected progressive hypovolemia in spontaneously breathing healthy volunteers during PEP and CPAP. An increase in PEP from baseline to 10 cmH2O augmented the increase in dPP, but not in dPOP.