The Victoria bomb: a report from the Westminster Hospital

Blood transfusions in mass casualty events: recent trends

BACKGROUND AND OBJECTIVES

The US AABB disaster task force recommends estimating 3 RBC units per admission (UPA) for mass casualty events (MCEs). In a previous analysis, median MCE UPA were 2·7 RBCs, 1·2 plasmas and 0·27 platelet doses (Vox Sang 2017; 112:648). Additional recent data were sought from the current era of balanced massive transfusion protocols (bMTPs).

MATERIALS AND METHODS

Publications in English from 1980 to 2020 were reviewed for MCEs using ≥50 RBCs/event and with numbers of admissions available. MCE reports were stratified by era and event-wide or trauma-centre source. The bMTP era included all MCEs since 2010 plus a 2008 bMTP military report.

STATISTICS

Mann-Whitney test.

RESULTS

Thirty-two MCEs met analysis criteria. Event-wide reports used medians [interquartile ranges] of 1·8 [1·2-3·9] RBC, 0·6 [0·3-0·9] plasma and 0·14 [0·06-0·26] platelet-dose UPA. Trauma centres transfused 3·4 [2·7-6·3] RBC, 2·4 [1·3-4·1] plasma and 0·41 [0·34-0·50] platelet-dose UPA, all P < 0·05 vs event-wide. Same-event median post-day-1 transfusions were 50% of day-1 use for RBC, 28% for plasma and 16% for platelets. Compared to prior years, the median plasma/RBC transfusion ratio rose from 0·28 to 0·67 in the bMTP era (P < 0·01). In recent mass shootings, trauma centres transfused up to 42 platelets (range 0·45-0·57 UPA) on day 1.

CONCLUSION

Based on available mass casualty data, we recommend planning for 3 RBC, 1 plasma and one-fourth platelet-dose units per admission for blood centres (event-wide), and 6, 4 and one-half UPA, respectively, for trauma centres, which have seen rising plasma usage and large mass-shooting platelet needs.

Blood component transfusions in mass casualty events

BACKGROUND AND OBJECTIVES

Planning transfusion needs in mass casualty events (MCE) is critical for disaster preparedness. Published data on blood component usage were analysed to seek correlative factors and usage rates.

MATERIALS AND METHODS

English-language medical publications since 1980 were searched for MCEs with numbers of patient admissions and transfused RBCs. Reports were excluded from natural disasters or with total RBC use <50 units. Statistical analysis employed Mann-Whitney U-tests and Spearman's rank correlations.

RESULTS

In 24 reports, the average units per admission were 3·06 RBCs, 2·13 plasmas and 0·37 platelet doses. Five RBCs per admission would have sufficed for 87% of events. Transfusion needs involving bombings correlated with admissions (P ≤ 0·03). In the formula (massive-transfusion patients in MCE) times X = (total units for all MCE patients), the average X was 35 for RBCs (correlation P = 0·01), 17 for plasma (P = 0·10) and five for platelet doses (P = 0·06). From 67% to 84% of all components used were given in the first 24 h (event medians).

CONCLUSIONS

Blood component use in MCEs correlated with numbers of patients admitted or receiving massive transfusion. More current data are needed to better reflect emerging trauma care practices and refine predictive models of transfusion needs.

Managing the surge in demand for blood following mass casualty events: Early automatic restocking may preserve red cell supply

BACKGROUND

Traumatic hemorrhage is a leading preventable cause of mortality following mass casualty events (MCEs). Improving outcomes requires adequate in-hospital provision of high-volume red blood cell (RBC) transfusions. This study investigated strategies for optimizing RBC provision to casualties in MCEs using simulation modeling.

METHODS

A computerized simulation model of a UK major trauma center (TC) transfusion system was developed. The model used input data from past MCEs and civilian and military trauma registries. We simulated the effect of varying on-shelf RBC stock hold and the timing of externally restocking RBC supplies on TC treatment capacity across increasing loads of priority one (P1) and two (P2) casualties from an event.

RESULTS

Thirty-five thousand simulations were performed. A casualty load of 20 P1s and P2s under standard TC RBC stock conditions left 35% (95% confidence interval, 32-38%) of P1s and 7% (4-10%) of P2s inadequately treated for hemorrhage. Additionally, exhaustion of type O emergency RBC stocks (a surrogate for reaching surge capacity) occurred in a median of 10 hours (IQR, 5 to >12 hours). Doubling casualty load increased this to 60% (57-63%) and 30% (26-34%), respectively, with capacity reached in 2 hours (1-3 hours). The model identified a minimum requirement of 12 U of on-shelf RBCs per P1/P2 casualty received to prevent surge capacity being reached. Restocking supplies in an MCE versus greater permanent on-shelf RBC stock holds was considered at increasing hourly intervals. T-test analysis showed no difference between stock hold versus supply restocking with regard to overall outcomes for MCEs up to 80 P1s and P2s in size (p < 0.05), provided the restock occurred within 6 hours.

CONCLUSION

Even limited-sized MCEs threaten to overwhelm TC transfusion systems. An early-automated push approach to restocking RBCs initiated by central suppliers can produce equivocal outcomes compared with holding excess stock permanently at TCs.

LEVEL OF EVIDENCE

Therapeutic/care management study, level IV.

40 years of terrorist bombings - A meta-analysis of the casualty and injury profile

INTRODUCTION

Terrorists have used the explosive device successfully globally, with their effects extending beyond the resulting injuries. Suicide bombings, in particular, are being increasingly deployed due to the devastating effect of a combination of high lethality and target accuracy. The aim of this study was to identify trends and analyse the demographics and casualty figures of terrorist bombings worldwide.

METHODS

Analysis of the Global Terrorism Database (GTD) and a PubMed/Embase literature search (keywords "terrorist", and/or "suicide", and/or "bombing") from 1970 to 2014 was performed.

RESULTS

58,095 terrorist explosions worldwide were identified in the GTD. 5.08% were suicide bombings. Incidents per year are increasing (P<0.01). Mean casualty statistics per incidents was 1.14 deaths and 3.45 wounded from non-suicide incidents, and 10.16 and 24.16 from suicide bombings (p<0.05). The kill:wounded ratio was statistically higher in suicide attacks than non-suicide attacks, 1:1.3 and 1:1.24 respectively (p<0.05). The Middle East witnessed the most incidents (26.9%), with Europe (13.2%) ranked 4th. The literature search identified 41 publications reporting 167 incidents of which 3.9% detailed building collapse (BC), 60.8% confined space (CS), 23.5% open space (OS) and 11.8% semi-confined space (SC) attacks. 60.4% reported on suicide terrorist attacks. Overall 32 deaths and 180 injuries per incident were seen, however significantly more deaths occurred in explosions associated with a BC. Comparing OS and CS no difference in the deaths per incident was seen, 14.2(SD±17.828) and 15.63 (SD±10.071) respectively. However OS explosions resulted in significantly more injuries, 192.7 (SD±141.147), compared to CS, 79.20 (SD±59.8). Extremity related wounds were the commonest injuries seen (32%).

DISCUSSION/CONCLUSION

Terrorist bombings continue to be a threat and are increasing particularly in the Middle East. Initial reports, generated immediately at the scene by experienced coordination, on the type of detonation (suicide versus non-suicide), the environment of detonation (confined, open, building collapse) and the number of fatalities, and utilising the Kill:Wounded ratios found in this meta-analysis, can be used to predict the number of casualties and their likely injury profile of survivors to guide the immediate response by the medical services and the workload in the coming days.

Mass-Casualty Terrorist Bombings In Istanbul, Turkey, November 2003: Report of the Events and the Prehospital Emergency Response

Background:

This paper describes the two mass-casualty, terrorist attacks that occurred in Istanbul, Turkey in November 2003, and the resulting prehospital emergency response.

Methods:

A complex, retrospective, descriptive study was performed, using open source reports, interviews, direct measurements of street distances, and hospital records from the American Hospital (AH) and Taksim Education and Research State Hospital (TERSH) in Istanbul.

Results:

On 15 November, improvised explosive devices (IEDs) in trucks were detonated outside the Neve Shalom and Beth Israel Synagogues, killing 30 persons and injuring an estimated additional 300. Victims were maldistributed to 16 medical facilities. For example, AH, a private hospital located six km from both synagogues, received 69 injured survivors, of which 86% had secondary blast injuries and 13% were admitted to the hospital. The TERSH, a government hospital located 1 km from both synagogues, received 48 injured survivors. On 20 November, IEDs in trucks were detonated outside the Hong Kong Shanghai Banking Corporation (HSBC) headquarters and the British Consulate (BC), killing 33 and injuring an estimated additional 450. Victims were maldistributed to 16 medical facilities. For example, TERSH, located 18 km from the HSBC site and 2 km from the the BC received 184 injured survivors, of which 93% had secondary blast injuries and 15% were hospitalized. The AH, located 9 km from the HSBC site and 6 km from the BC, received 16 victims.

Conclusion:

The twin suicide truck bombings on 15 and 20 November 2003 were the two largest terrorist attacks in modern Turkish history, collectively killing 63 persons and injuring an estimated 750 others. The vast majority of victims had secondary blast injuries, which did not require hospitalization. Factors associated with the maldistribution of casualties to medical facilities appeared to include the distance from each bombing site, the type of medical facility, and the personal preference of injured survivors.

Mass-Casualty, Terrorist Bombings: Epidemiological Outcomes, Resource Utilization, and Time Course of Emergency Needs (Part I)

Introduction:

This article characterizes the epidemiological outcomes, resource utilization, and time course of emergency needs in mass-casualty, terrorist bombings producing 30 or more casualties.

Methods:

Eligible bombings were identified using a MEDLINE search of articles published between 1996 and October 2002 and a manual search of published references. Mortality, injury frequency, injury severity, emergency department (ED) utilization, hospital admission, and time interval data were abstracted and relevant rates were determined for each bombing. Median values for the rates and the inter-quartile ranges (IQR) were determined for bombing subgroups associated with: (1) vehicle delivery; (2) terrorist suicide; (3) confined-space setting; (4) open-air setting; (5) structural collapse sequela; and (6) structural fire sequela.

Results:

Inclusion criteria were met by 44 mass-casualty, terrorist bombings reported in 61 articles. Median values for the immediate mortality rates and IQRs were: vehicle-delivery, 4% (1–25%); terrorist-suicide, 19% (7–44%); confined-space 4% (1–11%); open-air, 1% (0–5%); structural-collapse, 18% (5–26%); structural fire 17% (1–17%); and overall, 3% (1–14%). A biphasic pattern of mortality and unique patterns of injury frequency were noted in all subgroups. Median values for the hospital admission rates and IQRs were: vehicle-delivery, 19% (14–50%); terrorist-suicide, 58% (38–77%); confined-space, 52% (36–71%); open-air, 13% (11–27%); structural-collapse, 41% (23–74%); structural-fire, 34% (25–44%); and overall, 34% (14–53%). The shortest reported time interval from detonation to the arrival of the first patient at an ED was five minutes. The shortest reported time interval from detonation to the arrival of the last patient at an ED was 15 minutes. The longest reported time interval from detonation to extrication of a live victim from a structural collapse was 36 hours.

Conclusion:

Epidemiological outcomes and resource utilization in mass-casualty, terrorist bombings vary with the characteristics of the event.

Mass-Casualty, Terrorist Bombings: Implications for Emergency Department and Hospital Emergency Response (Part II)

This article reviews the implications of mass-casualty, terrorist bombings for emergency department (ED) and hospital emergency responses. Several practical issues are considered, including the performance of a preliminary needs assessment, the mobilization of human and material resources, the use of personal protective equipment, the organization and performance of triage, the management of explosion-specific injuries, the organization of patient flow through the ED, and the efficient determination of patient disposition. As long as terrorists use explosions to achieve their goals, mass-casualty, terrorist bombings remain a required focus for hospital emergency planning and preparedness.

Abdominal trauma in primary blast injury

BACKGROUND

Blast injury is uncommon, and remains poorly understood by most clinicians outside regions of active warfare. Primary blast injury (PBI) results from the interaction of the blast wave with the body, and typically affects gas-containing organs such as the ear, lungs and gastrointestinal tract. This review investigates the mechanisms and injuries sustained to the abdomen following blast exposure.

METHODS

MEDLINE was searched using the keywords 'primary blast injury', 'abdominal blast' and 'abdominal blast injury' to identify English language reports of abdominal PBI. Clinical reports providing sufficient data were used to calculate the incidence of abdominal PBI in hospitalized survivors of air blast, and in open- and enclosed-space detonations.

RESULTS

Sixty-one articles were identified that primarily reported clinical or experimental abdominal PBI. Nine clinical reports provided sufficient data to calculate an incidence of abdominal PBI; 31 (3·0 per cent) of 1040 hospitalized survivors of air blast suffered abdominal PBI, the incidence ranging from 1·3 to 33 per cent. The incidence for open- and enclosed-space detonations was 5·6 and 6·7 per cent respectively. The terminal ileum and caecum were the most commonly affected organs. Surgical management of abdominal PBI is similar to that of abdominal trauma of other causes.

CONCLUSION

Abdominal PBI is uncommon but has the potential for significant mortality and morbidity, which may present many days after blast exposure. It is commoner after blast in enclosed spaces and under water.

Impact of the terrorist bombings of the Hong Kong Shanghai Bank Corporation headquarters and the British Consulate on two hospitals in Istanbul, Turkey, in November 2003

BACKGROUND

The authors sought to estimate the impact of the terrorist bombings of the Hong Kong Shanghai Banking Corporation headquarters and the British consulate in Istanbul, Turkey, on November 20, 2003, on two nearby hospitals, in terms of epidemiologic outcomes, resource utilization, and time course of emergency needs.

METHODS

The authors used data from hospital records of injured survivors who used the emergency departments (EDs) at the Taksim Education and Research State Hospital (TERSH) and the American Hospital (AH) in Istanbul on November 20, 2003, to determine the totals and rates of mortality (early, late, and critical), injury, critical injury (Injury Severity Score > 15), ED use, hospitalization, operative care, and in-hospital overtriage and the time intervals of ED arrival.

RESULTS

The TERSH received 184 victims in the first hour after the initial blast, of which 88 (48%) were brought by emergency medical services, 171 (93%) had lacerations, 7 (4%) had penetrating eye injuries, 28 (15%) were hospitalized, 18 (10%) received operative care, and 7 (4%) were critically injured. Three deaths occurred in critically injured survivors, including one early death in the operating room and two late deaths on days 5 and 6. The AH received 16 victims, of which 14 (88%) had lacerations, 3 (19%) were hospitalized, 2 (13%) received operative care, and 1 (6%) was critically injured. An additional 4 victims were transferred to the AH from other hospitals, of which 3 were hospitalized and none were critically injured. No early or late deaths occurred.

CONCLUSION

Mortality, injury, and hospitalization rates at both hospitals were consistent with previous reports of open-air mass-casualty terrorist bombings. The TERSH experienced an unprecedented demand for ED surge capacity in an open-air bombing.

Case report: penetrating cardiac injury secondary to a terrorism-related nail bomb explosion

Penetrating cardiac injuries commonly occur secondary to gunshot or stab wounds. This is a report an unusual case of a patient who sustained a penetrating cardiac injury due to a nail from a terrorism-related, nail-bomb explosion. Associated problems included pericardial tamponade, penetrating cardiac injuries, acute, traumatic, myocardial infarction, and a penetrating lung injury. Prompt diagnosis and aggressive surgical intervention resulted in full recovery of the patient.

Mass casualty terrorist bombings

STUDY OBJECTIVE

We compared the epidemiologic outcomes of terrorist bombings that produced 30 or more casualties and resulted in immediate structural collapse, occurred within a confined space, or occurred in open air.

METHODS

We identified eligible studies of bombings through a MEDLINE search of articles published between 1966 and August 2002 and a manual search of published references. Pooled and median rates of mortality, immediately injured survival, emergency department use, hospitalization, and injury were determined for each bombing type.

RESULTS

We found 35 eligible articles describing 29 terrorist bombings, collectively producing 8,364 casualties, 903 immediate deaths, and 7,461 immediately surviving injured. Pooled immediate mortality rates were structural collapse 25% (95% confidence interval [CI] 6% to 44%), confined space 8% (95% CI 1% to 14%), and open air 4% (95% CI 0% to 9%). Biphasic distributions of mortality were identified in all bombing types. Pooled hospitalization rates were structural collapse 25% (95% CI 6% to 44%), confined space 36% (95% CI 27% to 46%), and open air 15% (95% CI 5% to 26%). Unique patterns of injury rates were found in all bombing types.

CONCLUSION

Patterns of injury and health care system use vary with the type of terrorist bombing.

Disasters and development: Part 2: understanding and exploiting disaster-development linkages

Disasters can impede the effectiveness of development resource allocation. The damage sustained from an event can be classified into four categories: (1) Loss of resources; (2) Interruption of programs and switching of crucial resources to other, shorter-term needs; (3) Negative impacts upon investment climates; and/or (4) Disruption of the non-formal sector (local businesses). Disasters have a particularly destructive economic impact in areas in which there are few alternatives for assets that are destroyed or in areas in which the resources already are at critical levels. Development processes can both increase and/or decrease the vulnerability of a society to hazards. There are dearly established linkages between poverty, marginalization, over-population, and vulnerability. To a large extent, vulnerability derives from poverty. The poor are more likely to live in vulnerable areas (slopes prone to landslides, flood plains, marginal agricultural land), have difficulty accessing education and information, have fewer assets to invest in resources to reduce vulnerability, and are more prone to become malnourished and have chronic illnesses that predispose them to injury and death. Development may be associated with the production of new hazards accepted by a society because the perceived benefits of the development project far exceed the relative risk associated with the project. Therefore, risk assessments must be part of any program planning and evaluation. Training and education are of critical importance in preventing increased vulnerability as a result of development strategies. Development also can progress in a manner that will result in mitigation of the impacts of an event on a given society (increase absorbing capacity and/or buffering capacity, elimination of hazards or the risk of them producing a disaster). Such mitigation measures can be either structural or nonstructural. There exists a wide range of options for incorporating mitigation measures in development projects. Two case studies provide exercises that incorporate the concepts provided in this discussion: (1) The 1985 earthquake in Mexico City; and (2) Agricultural development in northern Sudan.

Ocular injuries sustained by survivors of the Oklahoma City bombing

OBJECTIVE

The purpose of this study is to provide a review of the ocular injuries sustained by survivors of the April 19, 1995, bombing of the Alfred P. Murrah Federal Building in Oklahoma City.

DESIGN

Retrospective, noncomparative case series.

PARTICIPANTS

The authors retrospectively evaluated data collected on all surviving persons receiving ocular injuries during the bombing and on all at-risk occupants of the federal building and four adjacent buildings.

METHODS

Injury data from survivors were collected from multiple sources to include hospital medical records, a physician survey, emergency medical services run reports, written survivor accounts, building occupant survey, telephone interviews, and mail surveys.

MAIN OUTCOME MEASURES

The types of ocular injuries, the associated systemic injuries, and the location of the injured at the time of the blast were evaluated.

RESULTS

Fifty-five (8%) of the 684 injured bombing survivors sustained an ocular injury. Persons injured in the Murrah building were more than three times more likely to sustain an ocular injury than other injured persons. Seventy-one percent of ocular injuries occurred within 300 feet of the point of detonation. The most common serious ocular injuries included lid/brow lacerations (20 patients, 23 eyes), open globe injuries (12 eyes), orbital fractures (6 eyes), and retinal detachment (5 eyes). A retained intraocular foreign body accounted for only two of the injuries (4%). Glass accounted for nearly two thirds of the ocular injuries.

CONCLUSIONS

Blasts involving explosions inflict severe ocular injury, mostly as a result of secondary blast effects from glass, debris, etc. Eye injuries in bombings can probably be prevented by increasing the distance from and orientation away from windows (i.e., by facing desks away from windows). Use of such products as laminated glass, toughened window glazing, and Mylar curtains may reduce glass projectiles in the blast vicinity.

Emergency department impact of the Oklahoma City terrorist bombing

STUDY OBJECTIVE

To collect descriptive epidemiologic injury data on patients who suffered acute injuries after the April 19, 1995, Oklahoma City bombing and to describe the effect on metropolitan emergency departments.

METHODS

A retrospective review of the medical records of victims seen for injury or illness related to the bombing at 1 of the 13 study hospitals from 9:02 AM to midnight April 19, 1995. Rescue workers and nontransported fatalities were excluded.

RESULTS

Three hundred eighty-eight patients met inclusion criteria; 72 (18.6%) were admitted, 312 (80.4%) were treated and released, 3 (.7%) were dead on arrival, and 1 had undocumented disposition. Patients requiring admission took longer to arrive to EDs than patients treated and released (P =.0065). The EDs geographically closest to the blast site (1.5 radial miles) received significantly more victims than more distant EDs (P <.0001). Among the 90 patients with documented prehospital care, the most common interventions were spinal immobilization (964/90, 71.1%), field dressings (40/90, 44.4%), and intravenous fluids (32/90, 35.5%). No patients requiring prehospital CPR survived. Patients transported by EMS had higher admission rates than those arriving by any other mode (P <.0001). The most common procedures performed were wound care and intravenous infusion lines. The most common diagnoses were lacerations/contusion, fractures, strains, head injury, abrasions, and soft tissue foreign bodies. Tetanus toxoid, antibiotics, and analgesics were the most common pharmaceutical agents used. Plain radiology, computed tomographic radiology, and the hospital laboratory were the most significantly utilized ancillary services.

CONCLUSION

EMS providers tended to transport the more seriously injured patients, who tended to arrive in a second wave at EDs. The closest hospitals received the greatest number of victims by all transport methods. The effects on pharmaceutical use and ancillary service were consistent with the care of penetrating and blunt trauma. The diagnoses in the ED support previous reports of the complex but often nonlethal nature of bombing injuries.

Major incidents in Britain over the past 28 years: the case for the centralised reporting of major incidents

STUDY OBJECTIVES

To describe the incidence and epidemiology of major incidents occurring in Britain over the past 28 years.

METHODS

Major incidents were identified through a MEDLINE search, a hand search of journals and government reports at the Home Office Emergency Planning College, newspaper reports, a postal survey of ambulance emergency planning officers, and through requests for information posted on the internet.

MAIN RESULTS

Brief incidents profiles from 108 British major incidents are presented. Most major incidents pass unreported in the medical literature. On average three to four major incidents occur in Britain each year (range 0-11). Sixty three of 108 (59.2%) of incidents involve public transportation. The next two largest groups are civil disturbance 22 of 108 (20.3%) and industrial accidents 16 of 108 (14.8%). Although incidents at sports stadiums are rare they produce large numbers of casualties. The data currently available on major incidents are difficult to find and of questionable accuracy.

CONCLUSIONS

The lack of data makes planning for major incidents and exercising major incident plans difficult. Casualty incident profiles (CIPs) may assist major incidents exercises and planning. CIPs from future major incidents should be collated and made available to all major incident planners.

The casualty profile from the Manchester bombing 1996: a proposal for the construction and dissemination of casualty profiles from major incidents

OBJECTIVE

To produce a casualty profile for the Manchester bombing and to illustrate the potential uses of such templates in major incident planning.

METHODS

A retrospective review of casualty notes from the Manchester bombing.

RESULTS

A complete anonymous casualty profile for the Manchester bombing is given with AIS90 coded injuries. The majority (129, 62%) of casualties sustained minor injuries from flying glass. A significant number of casualties (36, 18%) presented with emotional distress or medical problems. A wide age range of casualties was involved. Few patients (19, 9%) required admission to hospital. There were no deaths and no casualties sustained major trauma.

CONCLUSIONS

Casualty profiles may be useful in the planning and testing of health service major incident plans. Such information should be easily accessible to all emergency planners.

Management of unique clinical entities in disaster medicine

This article discusses the management of clinical problems encountered particularly in disasters. These include the principles of multiple-casualty triage, and field and hospital management of blast injury, crush syndrome, compartment syndrome, particulate inhalation, and traumatic asphyxiation. The indications for extraordinary measures, such as field amputation, are detailed. A brief review of the causes and epidemiology of these entities is provided, with emphasis on the clinical management in the disaster setting.

A review of the management of a major incident involving predominantly paediatric casualties

On 27 September 1993 a double-decker bus full of secondary school children was involved in a collision with a lorry. A total of 58 people were injured, including two fatalities. All except two of the casualties were children. Forty-two casualties, including all of the seriously injured, were taken to the Accident & Emergency Department at York District Hospital. Fifteen casualties were admitted, the majority with closed head injuries. Most of the injuries were of a minor nature, predominantly soft-tissue damage and superficial lacerations. This paper reviews these injuries and the implementation of the hospital major accident (MAJAX) plan. It identifies specific problems encountered with this incident. It also describes the measures taken retrospectively to upgrade the MAJAX plan. It highlights the difficulties encountered by medical staff called to the incident who were unfamiliar with managing injuries and describes retrospective attempts to improve the awareness of trauma management skills.