Influence of prehospital management on the outcome of spinal cord decompression sickness in scuba divers

BACKGROUND

Decompression sickness (DCS) with spinal cord involvement has an unfortunately high rate of long-term sequelae. The objective of this study was to determine the association of prehospital variables on the outcome of spinal cord DCS, especially the influence of the initial clinical presentation and the time to recompression.

METHODS

This was a retrospective study using prospectively collected data which included divers with spinal cord DCS seen at a single hyperbaric centre study from 2010 to 2018. Information regarding dive, latency of onset of symptoms, time to recompression and prehospital management, that is, use of oxygen, treatment and means of evacuation, were analysed as predictor variables. The initial clinical severity was estimated by the score of the French society of diving and hyperbaric medicine (MEDSUBHYP). The primary end point was the presence or absence of sequelae at discharge assessed by the modified score of the Japanese Orthopedic Association.

RESULTS

195 divers (48±12 years, 42 women) were included. 34% had neurological sequelae at discharge. In multivariate analysis, a MEDSUBHYP score ≥6 and a time to recompression >194 min were significantly associated with incomplete neurological recovery (OR 9.5 (95% CI 4.6 to 19.8), p<0.0001 and OR 2.1 (95% CI 1.03 to 4.5), p=0.04, respectively). Time to recompression only appeared to be significant for patients with high initial clinical severity. As time to recompression increased, the level of sequelae also increased (p=0.014).

CONCLUSION

Determining the initial clinical severity is critical in identifying patients who need to be evacuated for recompression as quickly as possible.

Secondary transfer of emergency stroke patients eligible for mechanical thrombectomy by air in rural England: economic evaluation and considerations

Background

Mechanical thrombectomy (MT) is a time-sensitive emergency procedure for patients who had ischaemic stroke leading to improved health outcomes. Health systems need to ensure that MT is delivered to as many patients as quickly as possible. Using decision modelling, we aimed to evaluate the cost-effectiveness of secondary transfer by helicopter emergency medical services (HEMS) compared with ground emergency medical services (GEMS) of rural patients eligible for MT in England.

Methods

The model consisted of (1) a short-run decision tree with two branches, representing secondary transfer transportation strategies and (2) a long-run Markov model for a theoretical population of rural patients with a confirmed ischaemic stroke. Strategies were compared by lifetime costs: quality-adjusted life years (QALYs), incremental cost per QALY gained and net monetary benefit. Sensitivity and scenario analyses explored uncertainty around parameter values.

Results

We used the base case of early-presenting (<6 hours to arterial puncture) patient aged 75 years who had stroke to compare HEMS and GEMS. This produced an incremental cost-effectiveness ratio (ICER) of £28 027 when a 60 min reduction in travel time was assumed. Scenario analyses showed the importance of the reduction in travel time and futile transfers in lowering ICERs. For late presenting (>6 hours to arterial puncture), ground transportation is the dominant strategy.

Conclusion

Our model indicates that using HEMS to transfer patients who had stroke eligible for MT from remote hospitals in England may be cost-effective when: travel time is reduced by at least 60 min compared with GEMS, and a £30 000/QALY threshold is used for decision-making. However, several other logistic considerations may impact on the use of air transportation.

What fluids are given during air ambulance treatment of patients with trauma in the UK, and what might this mean for the future? Results from the RESCUER observational cohort study

OBJECTIVES

We investigated how often intravenous fluids have been delivered during physician-led prehospital treatment of patients with hypotensive trauma in the UK and which fluids were given. These data were used to estimate the potential national requirement for prehospital blood products (PHBP) if evidence from ongoing trials were to report clinical superiority.

SETTING

The Regional Exploration of Standard Care during Evacuation Resuscitation (RESCUER) retrospective observational study was a collaboration between 11 UK air ambulance services. Each was invited to provide up to 5 years of data and total number of taskings during the same period.

PARTICIPANTS

Patients with hypotensive trauma (systolic blood pressure <90 mm Hg or absent radial pulse) attended by a doctor.

PRIMARY AND SECONDARY OUTCOME MEASURES

The primary outcome was the number of patients with hypotensive trauma given prehospital fluids. Secondary outcomes were types and volumes of fluids. These data were combined with published data to estimate potential national eligibility for PHBP.

RESULTS

Of 29 037 taskings, 729 (2.5%) were for patients with hypotensive trauma attended by a physician. Half were aged 21-50 years; 73.4% were male. A total of 537 out of 729 (73.7%) were given fluids. Five hundred and ten patients were given a single type of fluid; 27 received >1 type. The most common fluid was 0.9% saline, given to 486/537 (90.5%) of patients who received fluids, at a median volume of 750 (IQR 300-1500) mL. Three per cent of patients received PHBP. Estimated projections for patients eligible for PHBP at these 11 services and in the whole UK were 313 and 794 patients per year, respectively.

CONCLUSIONS

One in 40 air ambulance taskings were manned by physicians to retrievepatients with hypotensive trauma. The most common fluid delivered was 0.9% saline. If evidence justifies universal provision of PHBP, approximately 800 patients/year would be eligible in the UK, based on our data combined with others published. Prospective investigations are required to confirm or adjust these estimations.

Impact of the introduction of an integrated adult retrieval service on major trauma outcomes

OBJECTIVES

The primary aim of this study was to examine the impact of the introduction of an integrated adult critical care patient retrieval system in Victoria, Australia, on early clinical outcomes for major trauma patients who undergo interhospital transfer. The secondary aims were to examine the impact on quality and process measures for interhospital transfers in this population, and on longer-term patient-reported outcomes.

METHODS

This is a cohort study using data contained in the Victorian State Trauma Registry (VSTR) for major trauma patients >18 years of age between 2009 and 2013 who had undergone interhospital transfer. For eligible patients, data items were extracted from the VSTR for analysis: demographics, injury details, hospital details, transfer details, Adult Retrieval Victoria (ARV) coordination indicator and transfer indicator, key clinical observations and outcomes.

RESULTS

There were 3009 major trauma interhospital transfers in the state with a transfer time less than 24 h. ARV was contacted for 1174 (39.0%) transfers. ARV-coordinated metropolitan transfers demonstrated lower adjusted odds of inhospital mortality compared with metropolitan transfers occurring without ARV coordination (OR 0.39, 0.15 to 0.97). Adjusting for destination hospital type demonstrates that this impact was principally due to ARV facilitation of a Major Trauma Service as the destination for transferred patients (OR 0.41, 0.16 to 1.02). The median time spent at the referral hospital was lower for ARV-coordinated transfers (5.4 h (3.8 to 7.5) vs 6.1 (4.2 to 9.2), p<0.0001).

CONCLUSIONS

In a mature trauma system, an effective retrieval service can further reduce mortality and improve long-term outcomes.

Air ambulance tasking: mechanism of injury, telephone interrogation or ambulance crew assessment?

OBJECTIVE

The identification of serious injury is critical to the tasking of air ambulances. London's Air Ambulance (LAA) is dispatched by a flight paramedic based on mechanism of injury (MOI), paramedical interrogation of caller (INT) or land ambulance crew request (REQ).This study aimed to demonstrate which of the dispatch methods was most effective (in accuracy and time) in identifying patients with serious injury.

METHODS

A retrospective review of 3 years of data (to December 2010) was undertaken. Appropriate dispatch was defined as the requirement for LAA to escort the patient to hospital or for resuscitation on-scene. Inaccurate dispatch was where LAA was cancelled or left the patient in the care of the land ambulance crew. The χ(2) test was used to calculate p values; with significance adjusted to account for multiple testing.

RESULTS

There were 2203 helicopter activations analysed: MOI 18.9% (n=417), INT 62.4% (n=1375) and REQ 18.7% (n=411). Appropriate dispatch rates were MOI 58.7% (245/417), INT 69.7% (959/1375) and REQ 72.2% (297/411). INT and REQ were both significantly more accurate than MOI (p<0.0001). There was no significant difference in accuracy between INT and REQ (p=0.36). Combining MOI and INT remotely identified 80.2% of patients, with an overtriage rate of 32.8%. Mean time to dispatch (in minutes) was MOI 4, INT 8 and REQ 21.

CONCLUSIONS

Telephone interrogation of the caller by a flight paramedic is as accurate as ground ambulance crew requests, and both are significantly better than MOI in identifying serious injury. Overtriage remains an issue with all methods.

Tissue oxygen saturation measurement in prehospital trauma patients: a pilot, feasibility study

BACKGROUND

This study evaluated the feasibility of prehospital tissue oxygen saturation (StO₂) in major trauma patients.

METHODS

A prospective, pilot feasibility study carried out in a physician based prehospital trauma service.

RESULTS

Prehospital StO₂ was recorded on 13 patients. Continuous StO₂ monitoring was achieved on all patients, despite intermittent failure of pulse oximetry and non-invasive blood pressure monitoring in six patients. No adverse outcomes of StO₂ monitoring were reported. The specific equipment used was reported to be inconveniently bulky and heavy for use in the prehospital setting.

CONCLUSIONS

Prehospital measurement and monitoring of StO₂ is feasible in trauma patients undergoing prehospital anaesthesia and may be useful in the early identification of shock, triggering of transfusion protocols and guiding fluid resuscitation.