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Abstract
Background Although prehospital cardiac arrest (CA) remains associated with poor long-term outcome, recent studies show an improvement in the survival rate after prehospital trauma associated CA (TCA). However, data on the long-term neurological outcome of TCA, particularly from physician-staffed Emergency Medical Service (EMS), are scarce, and results reported have been inconsistent. The objective of this pilot study was to evaluate the long-term outcome of patients admitted to several trauma centres after a TCA.
Methods This study is a retrospective database review of all patients from a multicentre prospective registry that experienced a TCA and had undergone successful cardiopulmonary resuscitation (CPR) prior their admission at the trauma centre. The primary end point was neurological outcome at 6 months among patients who survived to hospital discharge.
Results 88 victims of TCA underwent successful CPR and were admitted to the hospital, 90% of whom were victims of blunt trauma. Of these 88 patients, 10 patients (11%; CI 95% 6% to 19%) survived to discharge: on discharge, 9 patients displayed a GCS of 15 and Cerebral Performance Categories (CPC) 1–2 and one patient had a GCS 7 and CPC of 3. Hypoxia was the most frequent cause of CA among survivors. 6-month follow-up was achieved for 9 patients of the 10 surviving patients. The 9 patients with a good outcome on hospital discharge had a CPC of 1 or 2 6 months post discharge. All returned to their premorbid family and social settings.
Conclusions Among patients admitted to hospital after successful CPR from TCA, hypoxia as the likely aetiology of arrest carried a more favourable prognosis. Most of the patients successfully resuscitated from TCA and surviving to hospital discharge had a good neurological outcome, suggesting that prehospital resuscitation may not be futile.
- cardiac arrest
- pre-hospital
- Trauma, majot trauma management
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Key messages
What is already known on this subject?
Recent studies show an improvement in the survival rate after prehospital traumatic cardiac arrest. However data on the long-term neurological outcome are lacking.
What this study adds?
In this retrospective database review of a trauma registry in Paris, patients surviving after prehospital traumatic cardiac arrest mostly have good long-term neurological outcome. Attempting prehospital cardiopulmonary resuscitation and advanced airway management may therefore not be futile.
Introduction
Prehospital cardiac arrest (CA) remains associated with poor long-term outcome. Among circumstances associated with CA and its outcome, trauma is usually considered as particularly ominous. In 2003, the National Association of EMS Physicians Standards and Clinical Practice Committee of the American College of Surgeons Committee on Trauma Guidelines adopted a guarded position on the withholding and termination of prehospital cardiopulmonary resuscitation (CPR) during CA associated with trauma.1–3 Recently, an improvement in the rate of survival after traumatic CA (TCA) has been reported.4–8 However, data on the long-term neurological outcome of TCA, particularly from physician-staffed EMS, are scarce, and results reported have been inconsistent.
The objective of the present study was to evaluate the long-term outcome of patients admitted to several trauma centres after a TCA.
Methods
This observational study was based on the retrospective analysis of a multicentre prospective trauma registry from three centres in the Paris region (TraumaBase9) from January 2010 to January 2013. Patients suspected of major trauma according to prehospital assessment and triage criteria and transported to one of the three participating centres were included in the registry. Together these three centres cover 60% of all major trauma admissions in the region.
As previously described,9 the French EMS system has two systems of ambulances: paramedic-staffed ambulances (fire brigade squads in this area) or physician-staffed mobile intensive care unit (Service Mobile d'Urgence et de Réanimation (SMUR)). For those cases initially triaged as major trauma the SMUR team is systematically activated. All such patients in this cohort were managed by a physician-staffed mobile intensive care unit. CPR is performed according to the European Resuscitation Council guidelines until return of spontaneous circulation (ROSC) is achieved on-scene or the physician decides to discontinue CPR efforts.10
All patients from the registry that had experienced a TCA and undergone successful CPR with ROSC prior their admission were included. Patients who died before arrival were not screened, nor were they registered, as the EMS-dispatching centres of some regions were not connected to the central registry at the time. Patient characteristics, Utstein Style data (especially no flow time, defined as the time without chest compression in the first period of CA and low flow time, corresponding to CPR duration until ROSC), CPR modalities, full assessment at admission to the trauma Centre, the Injury Severity Score, outcome, GCS and Cerebral Performance Categories (CPC) at discharge were collected.11 The CPC ranges from 1 to 5 with 1 representing intact function and 5 representing brain death.12 The cause of the CA was determined by careful independent evaluation of all relevant case notes and documents by two investigators (F-XD, TG), including the detailed notes and interviews of the prehospital first responders and emergency physicians and the likely cause of arrest that the physician in charge suspected. Both investigators have extensive clinical experience in trauma and prehospital care. The decision was made on the basis of the prehospital notes, and after intense analysis of all available clinical and paraclinical data and circumstantial evidence, and elimination of other potential causes. In case of a disagreement, a third investigator was consulted (SH). If there was still disagreement, the cause was classified as unknown. All hospital survivors were followed up and their outcome, neurological performance (CPC Scale), quality of life and functional independence were evaluated at 6 months. This was by means of a phone interview made by a single investigator with the patients themselves or their relatives. A CPC of 1 or 2 was considered as good neurological outcome.
The primary end point was neurological outcome at 6 months among patients surviving to discharge from hospital. Data are expressed as medians (IQR 25–75) or percentages and compared using non-parametrical tests for quantitative data or a Fischer's exact test for qualitative data between survivors to discharge and deceased patients. All p values were two-tailed and a p<0.05 was considered as statistically significant. The 95% CI is given for the primary end point.
Results
Eighty-eight victims of TCA achieved ROSC after CPR and were subsequently admitted to hospital. Table 1 shows the epidemiological and clinical characteristics of the patients.
Epidemiological and clinical description of the population (n=88)
Of these 88 patients, 10 patients (11%; CI 95% 6% to 19%) survived to discharge: on discharge nine patients had a GCS score of 15 and CPC Score 1 (n=7) or 2 (n=2) and one patient was discharged with a GCS of 7 and CPC Score 3. Apart from similar no-flow times (0 (0–5) min), a better prognosis was observed among survivors with lower low flow time (table 2). On arrival at the receiving hospital, all patients who survived to discharge had already achieved ROSC, whereas none of the patients in persistent CA on arrival survived (n=35). Hypoxia was significantly more frequent among survivors than deceased (40% vs 6% respectively, p=0.01). Other suspected causes among survivors were: haemorrhage (three cases), traumatic brain injury (TBI, two cases) and myocardial contusion (one case). Detailed data on survivors are presented in table 3. It is noteworthy that patients with TBI presented with an isolated TBI. Patients categorised as TCA of hypoxic aetiology (patients # 3, 4, 5, 10) had multiple trauma with thoracic injuries. Patients for whom TCA was of haemorrhagic aetiology presented with either major vascular injuries, with patient # 7 walking through a glass pane and sustaining an axillary artery rupture, or polytrauma, with patient # 8 presenting with a retroperitoneal haematoma and fractures of the femoral shaft and pelvis.
Comparison between survivors and deceased patients
Characteristics of survivors
Follow-up was achieved for 9 of the 10 survivors. Consent for follow-up telephone interview was declined by the relatives of one patient (patient # 4 with a poor neurological outcome). The nine patients with a good outcome at hospital discharge had a CPC of 1 or 2 6 months after discharge. All returned to their premorbid family and social environments.
Discussion
To the best of our knowledge, this small pilot report is the first to evaluate the long-term neurological outcome after TCA. It showed a rather high hospital survival rate of 11% and a very good long-term neurological outcome in survivors. The overwhelming majority of the surviving patients had good long-term cerebral performance, with acceptable social integration and a return to professional activity for most of them.
The National Association of EMS Physicians (NAEMSP)-American College of Surgeons Committee on Trauma (ACSCOT) position paper recommends in particular to ‘withhold resuscitation for a blunt trauma patient who, on the arrival of EMS personnel, is found to be apneic, pulseless, and without organized electrocardiographic activity’. In the present study, interestingly almost all survivors presented with asystole on arrival of the EMS team. There are only a few reported cases of return of spontaneous circulation after asystole in traumatic CA.13 One possible explanation for this discordance could lie in the origin of the TCA. Consistent with the observation made by Lockey et al,6 our report suggests that where hypoxia is the likeliest cause of arrest, it is often associated with improved survival and better neurological outcome. Hypoxia corresponds to what the NAEMSP-ACSCOT position statement refers to as a ‘medical cause’ and recommends, ‘When the mechanism of injury does not correlate with the clinical condition, suggesting a non-traumatic cause of cardiac arrest, standard resuscitative measures should be followed’. The mechanism of injury and therefore arrest may not always be easy to identify for any prehospital EMS provider in particular in case of blunt, traumatic or spinal cord injury. In the present study it was impossible to determine the cause of the arrest in 22% of cases. In this situation or if a ‘medical’ cause is suspected, it may appear reasonable not to systematically withhold resuscitation of TCA, in particular when hypoxia may be the most likely cause. Asystole in a context of major trauma seems not to be an ideal single predictor of non-survival.
Different EMS organisations may explain in part the discordant survival rates for TCA between recent studies5 ,6 and studies from the USA.14 ,15 Data, such as those presented here, emanate from a physician-staffed EMS and show a better prognosis.5 ,6 Physicians of SMUR are senior physicians with at least 2 years' experience in Emergency Medicine or Critical Care and ALS, capable of performing advanced resuscitation interventions such as intubation, blood transfusion, thoracostomy and vasoactive medication administration. The presence of specifically trained prehospital physicians may have an impact on outcome.16 This has been documented in particular for physician-staffed Helicopter Emergency Services,17–19 but the present report may also suggest the same for physician-staffed ground-transport EMS.
Traditionally, resuscitative efforts for TCA in the context of acute haemorrhage have been considered futile. This position is largely consistent with historic and recently published studies and reproduced in the NAEMSP-ACSCOT position paper. In the present study, notably 30% of the survivors presented with ongoing haemorrhage. Based on such a small sample, it is difficult to conclude whether the present data corroborate the position of the NAEMSP-ACSCOT or suggest that attempting resuscitation in this patient group is worthwhile.
The main limitation of this report is the limited sample size and can as such only be considered as an exploratory pilot study. But the results may justify engaging in a prospective observational trial. Moreover, this series comes from a trauma registry and not from a CA registry. For this reason some Utstein Style items may not have been recorded resulting in missing data. Another major limitation is the selection of the population since patients that presented with TCA who were considered as deceased on-scene and not transported to a trauma centre were not included. As the number of such patients cannot be established, it is difficult to calculate with certainty the cohort's absolute survival rate and compare it to previous studies. Finally, the retrospective classification of the cause of the TCA is also susceptible to bias. This is of particular importance for the determination of a hypoxic cause for TCA. The investigators only concluded a hypoxic cause, if clear arguments were in favour of this conclusion. Arguments in favour of such a conclusion were, for example, a documented hypoxia present before TCA manifested, either witnessed by the paramedic first responders or the prehospital emergency physicians, rapid reversal of the arrest by oxygenation and ventilation. No conclusion was drawn when a doubt persisted. Given that in 22% of patients the cause of the arrest could not be determined and due to the retrospective determination of the cause of arrest, caution is indicated with regard to this conclusion. Given this limitation the online supplementary file provides more detail on all deceased patients and their likely cause of death (see online supplementary 1).
supplementary file
The results of the present study showed that TCA victims admitted to a trauma centre with a spontaneous circulation following successful prehospital CPR demonstrated an 11% survival rate to discharge and very good neurological outcome in the majority of survivors. Hypoxia appears as the most frequent cause of out-of-hospital CA for survivors as opposed to haemorrhage. In conclusion, our findings suggest that attempting prehospital resuscitation and advanced airway management in prehospital TCA may not be futile, particularly if hypoxia seems to be the likely cause of the arrest.
Acknowledgments
The authors thank Matthew Beardmore for his help in editing the manuscript.
References
Supplementary materials
Abstract in French
This web only file has been produced by the BMJ Publishing Group from an electronic file supplied by the author(s) and has not been edited for content.
- Abstract in French - Online abstract
Footnotes
Collaborators The Traumabase Group: Jacques Duranteau (Service d'Anesthésie-Réanimation, Hôpital Bicêtre, Groupement Hôpitaux Universitaires Paris Sud, AP-HP, Kremlin Bicêtre, France); Bruno Riou (Département d'Anesthésie Réanimation, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, AP-HP, Paris, France); Bernard Vigué (Service d'Anesthésie-Réanimation, Hôpital Bicêtre, Groupement Hôpitaux Universitaires Paris Sud, AP-HP, Kremlin Bicêtre, Franc); Olivier Langeron (Département d'Anesthésie Réanimation, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, AP-HP, Paris, France), Anatole Harrois (Département d'Anesthésie Réanimation, Groupe Hospitalier Pitié-Salpêtrière Charles Foix, AP-HP, Paris, France).
Contributors F-XD and TG signed the study. F-XD, TG, SH, MR and MG collected the data. F-XD, SH and TG wrote the paper. MR, JM and CPB reviewed the manuscript.
Competing interests None declared.
Ethics approval IRB of Paris South Hospitals, Assistance Publique-Hôpitaux de Paris. This registry has institutional support and receives funding from the Regional Health Authority (Agence Régionale de Santé d'Ile de France, ARS). The institutional review board approved the study (Comité de Protection des Personnes—Paris Sud). Written information was provided to inform patients and/or their next of kin of the data collection, purpose of the study and 6-month follow-up phone interview.
Provenance and peer review Not commissioned; externally peer reviewed.