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Abstract
Introduction The role of the military physician in Deployed Hospital Care involves the diagnosis and management of a wide variety of disease states. Broad clinical skills need to be complemented by judicious use of a limited array of investigations. No study has specifically quantified what investigations physicians use on operations.
Methods A retrospective cross-sectional study was performed to ascertain what investigations were undertaken on all patients managed by the General Internal Medicine teams over a 14 month period during a recent enduring operation in Afghanistan. A record was also made of investigations that were unavailable but considered desirable by the treating physician in order to inform clinical or occupational decisions.
Results 676 patients were admitted during the study period. Blood tests were performed in 96% of patients, plain radiographs in 50%, CT in 12% and ultrasound in 12%. An ECG was performed in over half (57%) and a peak flow in 11%. The most desirable, but unavailable, investigations were cardiac monitoring and echocardiography (24% and 12% of patients, respectively).
Discussion The data produced by this study both identified and quantified the investigations used by physicians during a mature operational deployment. This can be used in addition to accurate medical intelligence to inform and rationalise the diagnostic requirements for future operations as well as the provision of training. Technological advancements, particularly in weight and portability, are likely to enable more complex investigational modalities to be performed further forward on military deployments.
- telemedicine
- risk management
- diagnostic microbiology
- molecular diagnostics
- internal medicine
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Key messages
No prior study has prospectively evaluated the number and type of investigation modalities used by military internal physicians in the deployed environment.
This information will be used in conjunction with accurate medical intelligence to inform future operations.
Identification of investigations used in the deployed environment can be used to direct training requirements for military physicians.
Technological advancement and miniaturisation is likely to offer new options for deployable diagnostics to meet clinical demands and result in improved care.
Introduction
The workload of military General Internal Medicine (GIM) physicians in the Deployed Hospital Care setting differs considerably from that of a UK NHS hospital environment1. The majority of patients are men, young, have no premorbid disease and recover quickly. The deployed military GIM physician’s role remains wide-ranging, managing the majority of patients admitted to a field hospital with disease non-battle injury (DNBI), a term commonly used to describe conditions not attributed to traumatic battle injuries. This category may include psychiatric and paediatric admissions as well as those patients admitted due to the challenging effects of the local environment and climatic conditions1–3.
A previously published record of the workload of the GIM physicians in Afghanistan has documented the presenting symptoms, diagnoses, length of stay and disposal destinations of patients with DNBI presenting to the deployed field hospital.1 The deployments to Iraq and Afghanistan occurred in similar climates with considerable overlap in the endemic environmental or infectious diseases and, therefore, in patient presentation.4 The vast majority of presentations appear to be de nova diseases of largely infectious aetiology.1 A small proportion of the disease burden on operations are secondary to a further presentation of what was, prior to deployment, thought to be an asymptomatic disease (such as recurrent vasovagal syncope). To a lesser extent, the presentation was secondary to a relapse of chronic disease in the medically downgraded.5 6 The disease burden on future operations will continue to be influenced by the specific conflict, such as geographical or environmental conditions, the population at risk, endemic diseases and the extant Medical Rules of Engagement.
No previous study has evaluated what investigations physicians use or request during operational deployment. While UK combat operations in Afghanistan have long ceased and the size and complexity of the deployed field hospital is unlikely to be seen again in a generation, a review and analysis of the medical investigations that were performed may serve as a tabula rasa to prepare for future conflicts. This could benefit future medical intelligence, evacuation timelines, training and medical logistics.
This study of investigations requested on operations has three aims:
to identify what investigations GIM physicians used during the latter stages of a mature operational deployment
to identify unavailable investigations that, in the individual physician’s opinion, would have been useful to appropriately manage the patients clinically or occupationally in order to identify potential capability gaps
to review and discuss how technological advancement may change the face of diagnostic support to physicians on future operations.
Methods
A retrospective review of a prospectively maintained database of all patients admitted to the Role 3 hospital in Helmand Province Afghanistan over a 14-month period from April 2011 was performed. Data on all eligible GIM admissions were obtained including UK and allied military personnel, civilians and captured persons. Investigations ordered by other specialties, who were seen by the GIM physicians (often in the emergency department (ED) or as consults to primary care/other secondary care teams) but not admitted, were not included in the database so as to specifically focus on requests by GIM physicians only. Data were prospectively collected by successive GIM trainees and later cross-checked with the hospital electronic patient record to prevent omissions and errors. Patient details recorded included gender, rank (if applicable), nationality, age at admission, date of admission, length of stay, presenting symptoms, investigations undertaken, discharge diagnoses and disposal destination.
The deployed physicians managing the patients were also asked what further investigations they would have requested, had they been available, to aid either their initial management of the patient or the patient’s occupational disposition. Successive deployed GIM registrars were systematically recorded in the database whenever an investigation which would assist in the clinical or occupational management of the patient was desirable but unavailable. The decision relating to the diagnostic tests available was left to the discretion of the ‘expert opinion’ of the clinician.
Results
Data were collected on 676 patients (demographics are detailed in Table 1) as part of a larger subset.1 Civilians (123/676, 18%) included local nationals, captured persons and those employed to assist the running of Camp Bastion. Military patients included all nationalities making up the International Security Assistance Force including the Afghanistan National Army and Afghanistan National Police. The median age was 27 years (IQR 22–35 years). Overall, 22 different nationalities were seen, with the majority of patients being British (329/676, 49%) or American (188/676, 28%).
Demographics of patient population
The majority of patients were discharged from the Role 3 hospital and returned to their parent unit (478/676, 71%) with the remainder having their care transferred to an alternate Role 3 facility (tactical aeromed) or strategically aeromedically evacuated to definitive care (Role 4). Overall, three patients died (0.4%); one of stroke and the other two of recreational consumption of methanol. All deaths were in Afghan service personnel (Table 1).
The top 10 presenting complaints and subsequent discharge diagnoses are detailed in Table 2. The most common presenting complaints were diarrhoea and/or vomiting, chest pain, fever, collapse and headache, accounting for around half of the presentations (351/676, 52%). Subsequently, the most common discharge diagnoses were gastroenteritis, undifferentiated fever (due to unknown cause), heat illness, syncope and undifferentiated/troponin negative chest pain. It was acknowledged that troponin negative chest pain is not a specific diagnosis rather a term which is meant to convey that, following investigation, the patient was not thought to be undergoing an acute coronary syndrome.
The 10 most common presenting complaints and discharge diagnoses accounting for 71% of presenting complaints and 51% of discharge diagnoses
The most frequently requested investigations were common blood tests, namely full blood count, urea and electrolytes, liver function tests and C reactive protein (Table 3). Malaria immunochromatographic test and malaria films were requested in 18% (n=124/676) and 7% (n=49/676) of patients, respectively. A ‘Helmand fever’ screen, a serological test encompassing sandfly fever, spotted fever, epidemic typhus and Orientia tsutsugamushi (scrub typhus), was performed in 8% of patients. Although the ‘Helmand fever’ screen was requested, it was required to be sent back to the UK for processing. This resulted in a delay of around 3 weeks before the result was returned to the physician. An iSTAT is a rapid handheld point of care blood analyser (Abbot Point of Care Testing, Ottawa, Canada) delivering several rapid laboratory test results. Although deployed as a blood gas analyser, it was also used for rapid point of care estimation of haemoglobin, glucose and electrolytes. The test, for all these reasons, was performed in 15% of patients (n=100).
Investigations performed
Microbiological investigations reflected the presenting complaint and discharge diagnoses with stool culture for bacterial pathogens being the most commonly performed (150/676, 22%) followed by blood culture (n=83/676, 12%) and urine culture (n=65/676, 10%). There was a varied miscellany of laboratory tests which were unavailable in the deployed setting but requested (or desired) by physicians such as G6PD enzyme testing, haemoglobin electrophoresis and atypical pneumonia screening as well as serology testing for varicella, syphilis, Brucella and hydatid disease. In a few instances, these investigations were taken and sent back to the UK for analysis.
The most common radiograph performed was the CXR (47%, 320/676). A CT was performed in 25% (166/676) of patients with 17 (3%) patients having multiple body areas imaged. This included 10 CT chest, abdomen and pelvis scans, none of which were for the investigation of trauma.
Peak flow was recorded in 11% of patients. More comprehensive spirometry was unavailable, but in the most part, not considered necessary. Resting 12-lead ECGs were performed on over half of patients (386/676, 57%). Although perhaps not strictly considered an investigation, cardiac monitoring was desirable in 24% (161/676) of patients (Table 4). Formal cardiac monitoring was unavailable for patients admitted to the ward, but was available in the ED and intensive care unit. In 14 patients, cardiac monitoring was used on the ward. This may have been the use of defibrillator or ECG continuous monitoring, borrowing equipment from different locations or merely attributed from the use of cardiac monitoring in ICU or ED prior to the patient being transferred to the ward. A Holter monitor and exercise testing was also considered desirable in 6% and 4% of patients, respectively (Table 4). Physiotherapy treadmills with attached ECG machines were improvised for exercise testing. An echocardiogram would have been considered helpful in 13% of patients which is likely to reflect the significant number of patients presenting with syncope and chest pain.
Investigations desired but, in the most part, unavailable
Overall, in 9.5% of patients admitted under GIM, there was at least one investigation unavailable which the physician would have found desirable to optimally manage the patient from a clinical or occupational perspective.
Discussion
The aim of this review was to identify and quantify the investigations GIM physicians have used during a mature operational deployment. While such information will never obviate the requirement for accurate medical intelligence, it is very likely that, for non-theatre specific ailments, a similar collection of presenting complaints, namely diarrhoea and vomiting, chest pain, collapse and fever, will require a similar array of investigations. Medicine, unlike trauma, is not driven primarily by the operational tempo nor enemy tactics. Minimum investigations required to work-up these patients effectively include access to simple blood tests (96%), chest radiography (47%), microbiological analysis (43%) and ECG (57%).
These findings may influence and inform the rationalisation of the future deployment of investigational modalities. An example would be the availability of deployed CT scanning. While this has obvious use in the assessment of traumatic injuries, it was also used in a quarter of patients referred to physicians. While CT imaging would probably be unavailable in new entry operations, from a physician perspective, there appears to be an early requirement for the diagnostic assistance it delivers. Conversely, it is difficult to imagine an instance where MRI (performed in six patients in our cohort) would be required acutely to manage or occupationally assess a patient in theatre as opposed to aeromedically evacuating and performing MRI in a Role 4 environment.
Cardiac monitoring was unavailable outside of intensive care and ED, even in a mature operational deployment. While it was used in 2% of patients, this was not via dedicated ward-based cardiac monitoring devices. It was considered desirable in 24% of ward-managed patients. This could reflect the considerable numbers of patient presenting with collapse (11%) or with fever and concern regarding potential sepsis coupled with the desire to closely monitor patients for deterioration prior to aeromedical evacuation. While the equipment required to deliver cardiac monitoring can be bulky, expensive and require regular maintenance, novel wireless devices such as ECG patch monitoring and wireless vital sign monitoring may serve as a future technological solution.7 This could be of particular benefit in future chemical, biological, radiological and nuclear defence warfare environments and variants could be used for Holter monitoring and exercise testing.
Echocardiography was considered desirable in 13% of patients admitted to GIM and may reflect a shift in the expected standard of care over the last decade. The unavailability of echocardiography is likely secondary to both a skill and hardware deficit as rarely were both present at the same time. Echocardiography has proven a valuable tool in a variety of other deployed settings, specifically in the management of patents with Ebola,8 during damage control resuscitation9 and in the periarrest situation.10–12 However, the value of echocardiography outside of the deployed intensive care setting in definitely altering the patient’s immediate clinical or occupational management is less clear. Currently, there are no deployable echocardiogram sonographers or cardiac physiologists as the department of clinical measurements was disbanded in 2011–2012. However, increasingly physicians, primarily those in cardiology, acute medicine or intensive care specialists, possess this competency. These findings support both the deployment of ultrasound capable of basic echocardiography and basic training for deployed physicians. The advent of handheld or even smart-device echocardiography technology may support more widespread and forward use of this technology to provide limited point of care echocardiography.13
A further area where technological advancement is likely to have significant impact is in the investigation of infectious diseases. In this series, 11% of patients presented with an acute fever and 43% of the patients described had microbiological investigations. Commonly, diagnosis is retrospective, based on serological testing that is returned to the UK.14 These are often negative in the acute phase and a follow-up sample from the patient is required after 10–14 days. Most of these tests are only available from national reference laboratories and, therefore, have a turnaround of weeks.14 In addition, serological tests can be difficult to interpret due to cross-reactivity particularly in immunised individuals. While serology results can inform planning for future operations, it was not of use to deployed physicians at the point of care, as the patient had either recovered or been aeromedically evaluated by the time the results were available.15 It is now recognised that in the initial stages of presentation, detection of nucleic acid via PCR from a variety of body fluids is both more rapid and often more accurate than serology.16 17 While these samples can be returned to the UK, there is a necessity to preserve the nucleic acid, and this requires a robust cold chain. Recent technological advancement and early adoption, by the Defence Medical Services, of deployable PCR capability has meaningfully informed real-time patient management.18 The use of automated blood cultures and rapid diagnostics in conjunction with the BioFire Film Array (BioMérieux, France), a multiplex PCR system, has been described in the diagnosis of febrile illness in the UK Military Ebola treatment centre.19 Genomic sequencing was also possible in Sierra Leone in as little as 15–60 min giving real-time genomic surveillance.20 This capability will continue to evolve, and early evaluation and adoption of new technologies remain a priority. The potential benefit is delivery of a more accurate and rapid diagnosis to better inform clinical management, infection control, force protection and public health. The availability of rapid diagnostics may further enable early discharge and help to maintain the deployed hospital capability. While rapid diagnostic testing is desirable in targeting and narrowing antibiotic usage, as well as the accurate and rapid management of outbreaks, a specific military use to these technologies is in the field of biological warfare enabling rapid diagnosis and the instigation of immediate and effective management and force protection measures.18
The advancement of telemedicine may bridge the gap between deployed generalists and non-deployed specialist expertise in the firm base, building on the ‘reach-back’ services already used on operational deployment. As well as offering specialist expertise or a second opinion, it is conceivable that investigations could be interpreted, or even performed, via telemedicine (eg, Zio Patch, iRhythm technologies, San Francisco, California, USA or SEEQ Mobile Cardiac Telemetry System, Medtronic, Minneapolis, Minnesota, USA), which may significantly decrease the requirements for particular deployed expertise. This could, however, be limited by the early enduring requirement for advanced signals support.
There are several limitations to this study. We acknowledge that data were collected in a mature operation in a well-staffed and resourced Role 3 hospital with maximal deployable laboratory and radiological investigations. Future contingency operations will come with operational and logistical constraints that may limit the potential deployment of diagnostics, such as in a Role 2 light manoeuvre scenario. However, this paper has demonstrated that technological advancement can mitigate this with the capability to deploy lightweight high-fidelity diagnostics, producing the so-called ‘biomedical scientist in a bergan’. Our aim was to also ascertain what physicians used and desired during a mature conflict to serve as a driver to investigate rapidly deployable robust solutions for future operational deployments as seen during Operation GRITROCK.
We acknowledge that the data are not contemporary and represent a subset of a larger dataset.1 Contrasting to recent conflicts however, it remains highly relevant for non-endemic diseases as well as for infectious diseases which are often prevalent in new entry operations such as those causing diarrhoeal illnesses. While there is the potential for overlap from previous conflicts, physician’s toolkits must reflect specific local medical intelligence especially in terms of envenomation and prevalent infectious diseases as well as the potential use of chemical, biological, radiological and nuclear weapons.
While every effort was made to ensure that the collection of data on desirable but unavailable investigations was systematic, we acknowledge the potential for bias from what represents a clear ‘expert opinion’. Furthermore, just because an investigation is desirable does not mean it is essential, and we have presented no evidence that the number or type of investigations performed, whether existing or desirable, altered patient care, outcome or rates of medical evacuation. While the specificity and sensitivity of investigations were beyond the scope of this observational paper, the occupational ramifications of investigations should be further studied. However, such a study would be difficult to perform as occupational medicine involves the management of risk. The deployed consultant physician is the ‘deployed expert’ using investigations to provide the ‘assurance’ required to safely return patients to their units and reduce medical evacuation numbers. In our study, a quarter of patients required medical evacuation to Role 4 which arguably has a significant impact on force preservation. Potentially less access to investigations in new entry operations could impact force preservation. This requires further study.
Conclusion
This paper provides a record of the investigations physicians use during a mature operation. This can be used alongside medical intelligence assessments to inform the diagnostic requirements for future operations and the training required to deliver these. The data support the continued requirement for radiology even in the early phases of a new entry operation and the continued early adoption of novel laboratory capability. Technological advancement in the future is likely to allow for complex diagnostics platforms to be highly portable and thus rapidly deployable even into far forward locations.
References
Footnotes
Contributors IP: drafting and research of the manuscript. EJH: critical review of the content. IG: critical review of the content and data collection. JL: data collection. DW: critical review of the content. ATC: drafting the manuscript and overarching review of the content.
Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.
Competing interests None declared.
Patient consent Not required.
Provenance and peer review Not commissioned; externally peer reviewed.