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Abstract
Background Traumatic cardiac arrest (TCA) in children is associated with a low probability of survival and poor neurological outcome in survivors. Since 2003, over 600 seriously injured local national children have been treated at deployed UK military medical treatment facilities during the Iraq and Afghanistan conflicts. A number of these were in cardiac arrest after sustaining traumatic injuries. This study defined outcomes from paediatric TCA in this cohort.
Methods A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry. This includes UK military, coalition military, civilians and local security forces personnel who prompted trauma team activation. All children in this series were local nationals. Patients aged less than 18 years who presented between January 2003 and April 2014, and who underwent cardiopulmonary resuscitation, were included.
Results 27 children with TCA were included. Four children survived to discharge from the medical treatment facility (14.8%), though limited data are available regarding the long-term neurological outcome in these patients.
Conclusions This study demonstrates that the outcomes for paediatric TCA in our military field hospitals were similar to other paediatric civilian and adult military studies, despite patients being injured by severe blast injuries. Further work is needed to define the optimal management of paediatric TCA.
- ACCIDENT & EMERGENCY MEDICINE
- TRAUMA MANAGEMENT
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Key messages
Paediatric traumatic cardiac arrest (TCA) is associated with a low probability of survival and poor neurological outcome in survivors.
This study highlights that the outcomes for paediatric TCA in our military field hospitals were similar to paediatric civilian and adult military studies.
This is despite patients being injured by severe blast injuries. Further work is needed to define the optimal management of paediatric TCA.
Introduction
Trauma is a leading cause of death in children over 1 year of age.1 Paediatric traumatic cardiac arrest (TCA) is associated with poor survival and worse neurological outcome. Reported survival rates vary considerably, possibly due to different definitions of TCA, mechanisms of trauma and prehospital factors.
TCA secondary to mechanisms involving drowning or obstruction to the airway, leading to a primary respiratory arrest, appear to have better outcomes.2–4 Factors that may influence survival include prehospital cardiopulmonary resuscitation (CPR),4 ,5 physician-led prehospital care3 ,5 and the use of emergency thoracotomy,6 though no single adjunct to basic resuscitation protocols has been shown to significantly alter outcome.7
Survival to discharge from hospital has been reported in 5.4%8 and 6.7%9 of children sustaining paediatric TCA, although some single-centre studies, especially those excluding drowning-type mechanisms, have shown lower survival rates.10 Neurological outcome is universally reported as poor, with the rate of survivors with a ‘good’ neurological outcome (diagnosed by various criteria) ranging from 0% to 6.6%.5 ,11
The vast majority of literature on paediatric TCA originates from civilian practice, where injury patterns differ from those seen during armed conflicts. The previously reported incidence of injuries due to explosives and gunshot wounds (GSW), especially high energy transfer rounds, are low.
Since 2003, over 600 seriously injured local national children have been treated at deployed UK medical treatment facilities during the Iraq and Afghanistan conflicts. Over this period, trauma care has advanced, with more unexpected survivors than previously seen.12 The development of airway competent physician-led retrieval teams (MERT—Medical Emergency Response Team), novel haemostatic agents, massive transfusion policies and damage control resuscitation are factors that may be associated with improved survival.13 A number of children treated in the UK facilities were in TCA prior, during or after arrival. The aim of this study was to define outcome in terms of survival to hospital discharge in children presenting to deployed medical treatment facilities in TCA.
Methods
A retrospective database review was undertaken using the UK Joint Theatre Trauma Registry (JTTR). This registry includes UK military, coalition military, civilians and local security forces personnel who prompted trauma team activation within a deployed medical treatment facility. Patients were included if they were aged less than 18 years, presented between January 2003 and April 2014 and if they underwent CPR as defined in the JTTR field form.
Data included age, mechanism of injury, abbreviated injury scale (AIS), injury severity score (ISS), new ISS, interventions and survival (to discharge from deployed medical treatment facility). Outcome in terms of cognitive recovery or neurological impairment is not recorded in the registry. All children in this series were local nationals.
TCA is defined in a variety of ways in the literature. Some papers include,5 exclude10 ,14 and subgroup analyse4 ,9 traumatic asphyxiation (drowning, suffocation, etc) as a cause of TCA. For the purpose of this paper, we have excluded deaths due to traumatic asphyxiation, defining TCA as cardiac arrest due to blunt or penetrating trauma.
Anonymised data were supplied from the JTTR database, and according to institutional agreement, ethical approval was not required.
Results
Overall, 27 children met the inclusion criteria and comprised the study population; six were female. Ten (37%) had a return of spontaneous circulation (ROSC) with four children (14.8%) surviving to discharge into the local healthcare system—five children had drowned or asphyxiated, and were excluded from further analysis.
Cultural factors meant that an exact date of birth was often not known, leading to medical teams estimating the age of local children at the time of treatment. The children ranged in age between 3 and 15 years, with an average age of 10 years. The mechanisms of injury are shown in Table 1. There was a median ISS of 25 (IQR 16–59). The AIS body region, which had sustained the most severe injury, along with the other injuries sustained, is shown in Table 2.
Mechanism of injury, ROSC and survival to discharge
Injury patterns and abbreviated injury scale region
A variety of interventions were used in these patients, with the most common interventions shown in Table 3. In the 10 patients who had ROSC, seven patients underwent damage control surgery (involving either a thoracotomy or laparotomy). The principal indication was to relieve cardiac tamponade or to gain proximal control of bleeding.
Interventions performed
The characteristics of those patients surviving to discharge are shown in Table 4.
Survivor characteristics
The neurological outcome of two of the survivors is unknown. One survivor, an 8-year-old boy injured by an improvised explosive device (IED), had significant neurological impairment due to hypoxic brain injury. The other survivor, a 12-year-old who sustained abdominal injuries, had a good neurological outcome, and was reported by the trauma team leader as playing football on the ward prior to discharge (K Hartington, ED Consultant, Camp Bastion, personal communication, September 2014).
Discussion
This study has shown that in this small series of paediatric patients sustaining TCA, 37% had ROSC and 14.8% survived to discharge. The survival to discharge and frequency of ROSC appears to be similar to other literature on the topic. In systematic reviews of the literature, ROSC was reported to have occurred in 22.8% of cases,9 though more recently published studies have shown both lower (20%10) and higher rates of ROSC (42%14). Survival to discharge from hospital has been reported in 5.4%15 and 6.7%9 of children sustaining paediatric TCA. Some single studies, especially those that excluded drowning as a mechanism, showed lower survival rates.10 One Spanish study has demonstrated a survival rate of 23.1%,5 though this seems to stand apart from other studies.
Previous literature on paediatric TCA has originated from the civilian setting, with little data published from conflict zones. Military clinicians often work in austere environments, alongside multinational teams with varying paediatric emergency medicine experience. Our study population sustained injuries from mechanisms rarely seen in civilian practice, such as high energy transfer GSWs and blast injuries. Direct comparison must, therefore, be undertaken with caution, though it does suggest that our outcomes are comparable with civilian studies, despite patients suffering severe blast injuries.
Tarmey et al16 examined adult traumatic cardiopulmonary arrest at the same medical facility during the same conflict in Afghanistan. In a study of 52 adults, they demonstrated ROSC in 27% of cases with 8% survival to discharge, all with a good neurological outcome. Our survival outcomes for children during the same conflict are comparable.
Neurological outcome is not recorded in the JTTR, although personal communication with the clinical team was possible for two of the cases that survived. In a systematic review, Donoghue et al9 showed a rate of good neurological outcome of 0.3% for traumatic injuries alone, excluding submersion injuries. Fallat et al8 showed that a good neurological outcome was recorded in only 19 out of 1114 (1.7%) paediatric TCAs.
The most common mechanism of injury reported in previous studies is from blunt trauma. This was the least common mechanism in our study. The IED was the predominant weapon used during the Afghanistan conflict, and hence, was the most frequent mechanism of injury in our study. Massive haemorrhage predominates as a cause of death in these patients.
Certain interventions were frequently undertaken during resuscitation, including intubation and blood transfusion. Novel haemostatic agents, limb tourniquets and intraosseous needles were used frequently in children sustaining ROSC and surviving to hospital discharge. The use of novel haemostatic agents, intraosseous access devices, improved battlefield casualty care, prehospital physician-led care, well-trained and experienced trauma teams and paediatric massive transfusion policies17 are all possible factors that may have contributed to survival. However, this study cannot attribute survival to any one intervention. Intraosseous needles are commonly used and widely accepted in military practice,18 and were used in nearly half of our patients, with ROSC obtained in many cases.
Damage control surgery is often undertaken as part of damage control resuscitation. Right turn resuscitation19 is a strategy developed at the medical treatment facility in Camp Bastion, Afghanistan, where the trauma team meets the patient, and resuscitation begins in the operating theatre to facilitate immediate surgical intervention. In certain patients, rapid proximal control of bleeding by aortic cross clamping allows the chance to ‘turn off the tap’ and transfuse blood products to restore the circulation—seven of the children in whom ROSC was achieved had damage control surgery during the initial phase of resuscitation. This appears to be a beneficial strategy in massive blood loss due to trauma. All of the survivors in our study underwent damage control surgery.
Recent conflicts have highlighted that paediatric resuscitation skills are vital in military clinicians. It is, therefore, vital that these skills are maintained and developed in preparation for future conflict. This includes paediatric specific training for all military medical personnel (eg, military augmented APLS) working in major trauma centres, treating children on a regular basis and retaining some paediatric subspecialists within regular or reserve staff.
Five children were excluded from our study due to death caused by traumatic asphyxiation. It is of note that all of these died with a much lower average age of 3. All these children appear to have had long extraction times to a medical facility. This appears in contrast to other studies where this subgroup of patients have improved survival.2–4
Limitations
The analysis of military injury data can be inherently difficult when data is collected in the often-austere conditions of the battlefield.20 Limitations of this study are inherent in the data contained within the JTTR. The outcome data available are limited to survival to discharge from the medical treatment facility; so, longer-term outcome data are not available from this type of study. The number of children included in this study was small. It is, therefore, difficult to ascertain, which interventions may have a proven survival benefit. As the definition of TCA varies between papers in the literature, direct comparison of our study is difficult.
The enduring nature of the conflict in Afghanistan has led to the advances in trauma care, and produced a unique facility. A hospital dedicated to the management of major trauma, with consultant-led trauma teams seeing large quantities of severely injured trauma patients, mean that the results of our study may be difficult to replicate in civilian practice.
Conclusions
Paediatric TCA is associated with poor outcome, but is not universally fatal. This study highlights the outcome for paediatric TCA in our well-established field hospitals were similar to other paediatric civilian and adult military studies. This is despite patients being injured by severe blast injuries. Further work is needed to define the optimal management of paediatric TCA.
References
Footnotes
Contributors CMH is responsible overall for content, and has been key author. MR has supported the data gathering efforts alongside AR. JES has provided academic support, aiding in the editing.
Competing interests None declared.
Provenance and peer review Not commissioned; externally peer reviewed.