Risk of late perforation in intestinal contusions caused by explosive blast

Outcome of trauma-related emergency laparotomies, in an era of far-reaching specialization

Background

Far reaching sub-specialization tends to become obligatory for surgeons in most Western countries. It is suggested that exposure of surgeons to emergency laparotomy after trauma is ever declining. Therefore, it can be questioned whether a generalist (i.e., general surgery) with additional differentiation such as the trauma surgeon, will still be needed and can remain sufficiently qualified. This study aimed to evaluate volume trends and outcomes of emergency laparotomies in trauma.

Methods

A retrospective cohort study was performed in the University Medical Center Utrecht between January 2008 and January 2018, in which all patients who underwent an emergency laparotomy for trauma were included. Collected data were demographics, trauma-related characteristics, and number of (planned and unplanned) laparotomies with their indications. Primary outcome was in-hospital mortality; secondary outcomes were complications, length of ICU, and overall hospital stay.

Results

A total of 268 index emergency laparotomies were evaluated. Total number of patients who presented with an abdominal AIS > 2 remained constant over the past 10 years, as did the percentage of patients that required an emergency laparotomy. Most were polytrauma patients with a mean ISS = 27.5 (SD ± 14.9). The most frequent indication for laparotomy was hemodynamic instability or ongoing blood loss (44%).Unplanned relaparotomies occurred in 21% of the patients, mostly due to relapse of bleeding. Other complications were anastomotic leakage (8.6%), intestinal leakage after bowel contusion (4%). In addition, an incisional hernia was found in 6.3%. Mortality rate was 16.7%, mostly due to neurologic origin (42%). Average length of stay was 16 days with an ICU stay of 5 days.

Conclusion

This study shows a persistent number of patients requiring emergency laparotomy after (blunt) abdominal trauma over 10 years in a European trauma center. When performed by a dedicated trauma team, this results in acceptable mortality and complication rates in this severely injured population.

Pathophysiology of primary blast injury

The majority of patients injured in the recent conflicts in Iraq and Afghanistan were as a result of explosion, and terrorist incidents have brought blast injuries to the front door of many civilian hospitals that had not previously encountered such devastation. This article reviews the physics and pathophysiology of blast injury with particular relevance to the presentation and management of primary blast injury, which is the mechanism least familiar to most clinicians and which may cause devastating injury without externals signs.

A report of three cases and review of the literature on rectal disruption following abdominal seatbelt trauma

Seatbelt associated blunt trauma to the rectum is a rare but well recognised injury. The exact mechanism of hollow visceral injury in blunt trauma is unclear. Stress and shear waves generated by abdominal compression may in part account for injury to gas containing structures. A 'seatbelt sign' (linear ecchymosis across the abdomen in the distribution of the lap belt) should raise the suspicion of hollow visceral injuries and can be more severe with disruption of the abdominal wall musculature. Three consecutive cases of rectal injury following blunt abdominal trauma, requiring emergency laparotomy and resection, are described. Lumbar spine injury occurred in one case and in the other two cases, there was injury to the iliac wing of the pelvis; all three cases sustained significant abdominal wall contusion or muscle disruption. Abdominal wall reconstruction and closure posed a particular challenge, requiring a multidisciplinary approach. The literature on this topic is reviewed and potential mechanisms of injury are discussed.

Abdominal blast injuries: different patterns, severity, management, and prognosis according to the main mechanism of injury

PURPOSE

To review the frequency, different patterns, anatomic severity, management, and prognosis of abdominal injuries in survivors of explosions, according to the main mechanism of injury.

METHODS

A MEDLINE search was conducted from January 1982 to August 2013, including the following MeSH terms: blast injuries, abdominal injuries. EMBASE was also searched, with the same entries. Abdominal blast injuries (ABIs) have been defined as injuries resulting not only from the effects of the overpressure on abdominal organs, but also from the multimechanistic effects and projectile fragments resulting from the blast. Special emphasis was placed on the detailed assessment of ABIs in patients admitted to GMUGH (Gregorio Marañón University General Hospital) after the Madrid 2004 terrorist bombings, and in patients admitted to HYMC (Hillel Yaffe Medical Centre) in Hadera (Israel) following several bombing episodes. The anatomic severity of injuries was assessed by the abdominal component of the AIS, and the overall anatomic severity of casualties was assessed by means of the NISS.

RESULTS

Abdominal injuries are not common in survivors of terrorist explosions, although they are a frequent finding in those immediately killed. Primary and tertiary blast injuries have predominated in survivors from explosions in enclosed spaces reported outside of Israel. In contrast, secondary blast injuries causing fragmentation wounds were predominant in suicide bombings in open and/or semi-confined spaces, mainly in Israel, and also in military conflicts. Multiple perforations of the ileum seem to be the most common primary blast injury to the bowel, but delayed bowel perforations are rare. Secondary blast injuries carry the highest anatomic severity and mortality rate. Most of the deaths assessed occurred early, with hemorrhagic shock from penetrating fragments as the main contributing factor. The negative laparotomy rate has been very variable, with higher rates reported, in general, from civilian hospitals attending a large number of casualties.

CONCLUSIONS

The pattern, severity, management, and prognosis of ABI vary considerably, in accordance with the main mechanism of injury.

Combat Casualty Care research programme

The Combat Casualty Care research programme is an integrated suite of projects designed to address Defence Medical Services' research needs for casualty care. The programme covers a broad spectrum of topics ranging from the pathophysiological and immunological impact of military relevant injuries to the effects of these disturbances on the response to early treatment. Dstl Porton Down has a long history of studying military injuries and has developed models, both in vivo and physical, to address the research needs. The work is conducted in close collaboration with clinical colleagues at the Royal Centre for Defence Medicine who have direct experience of the clinical issues faced by combat casualties and insights into the potential clinical implications of emerging strategies. This article reviews progress in research areas spanning forward resuscitation, with a particular focus on blast-related injuries, trauma coagulopathy, effects of drugs on the response to haemorrhage and deployed research. A significant 'value added' component has been the underpinning of higher degrees for seconded military clinicians at Dstl Porton Down who have made a valuable contribution to the overall programme.

What the Intensive Care Doctor Needs to Know about Blast-Related Lung Injury

Explosions are currently the primary cause of military combat injuries. A minority of civilian trauma is also caused by explosions. People hurt by explosion are likely to present with complex injuries. The aim of the article is to explain the mechanism underlying these injuries and the associated physiology to help the intensive care clinician manage these casualties properly. The generic term ‘blast injury’ is applied to a collection of injuries caused by explosion. Components of blast injuries have precise definitions relating to the elements of the explosion that caused the injuries: primary blast injury is due to a shock wave, secondary blast injury is caused by fragments and debris colliding with the victim and tertiary blast injury is due to the casualty being thrown against solid objects. Primary blast injury results in damage principally in gas-containing organs, eg the lungs (blast lung) and can lead to impaired pulmonary gas transfer and hypoxaemia. Secondary blast injuries are often penetrating and can lead to haemorrhage while tertiary blast injuries are often blunt and involve substantial tissue damage. Survivors of explosions in confined spaces are more likely to exhibit primary blast injury than those injured in open spaces. The current military approach to immediate management is to apply the C ABC principle (arrest catastrophic haemorrhage first and then deal with airway, breathing and circulation) to achieve Damage Control Resuscitation. Early administration of blood products (plasma as well as red cells) is advocated for those suffering significant haemorrhage. Initial resuscitation is hypotensive to minimise risk of dislodging nascent clots. However, if evacuation is protracted (longer than one hour) then consideration should be given to improving blood flow / oxygen delivery by adopting a revised normotensive blood pressure target to reverse the deleterious consequences of the hypotensive shock state. Animal studies have shown that titrating FiO2 to a target SaO2 of 95% can improve survival and ‘buy time’ during hypotensive resuscitation. Ventilator strategies should use a lung-protective approach with permissive hypercapnia if necessary. Blast casualties are often a challenging group of patients needing expert, tailored, care. Outcome can be good especially in young, otherwise fit, casualties with more than 96% surviving to ICU discharge, although this figure may be lower with a mixed civilian group.

Blast injuries

Health-care providers are increasingly faced with the possibility of needing to care for people injured in explosions, but can often, however, feel undertrained for the unique aspects of the patient's presentation and management. Although most blast-related injuries (eg, fragmentation injuries from improvised explosive devices and standard military explosives) can be managed in a similar manner to typical penetrating or blunt traumatic injuries, injuries caused by the blast pressure wave itself cannot. The blast pressure wave exerts forces mainly at air-tissue interfaces within the body, and the pulmonary, gastrointestinal, and auditory systems are at greatest risk. Arterial air emboli arising from severe pulmonary injury can cause ischaemic complications-especially in the brain, heart, and intestinal tract. Attributable, in part, to the scene chaos that undoubtedly exists, poor triage and missed diagnosis of blast injuries are substantial concerns because injuries can be subtle or their presentation can be delayed. Management of these injuries can be a challenge, compounded by potentially conflicting treatment goals. This Seminar aims to provide a thorough overview of these unique primary blast injuries and their management.

Mechanisms of injury by explosive devices

Explosive devices cause injury by four mechanisms, of which primary blast injury is the least familiar to most non-military clinicians. The pathophysiology of the various mechanisms of injury is described, and the implications for translating a knowledge of mechanism of injury to clinical management is discussed.

Terrorist Homicide Bombings: A Primer for Preparation

Contemporary planning for disaster response to terrorist events usually assumes the use of chemical, radiological, or biological weapons. Historically, most victims of terrorist attacks are injured by the use of conventional explosives rather than weapons of mass destruction. Such attacks will likely produce victims who have suffered burn injuries along with conventional trauma. Alternately, the large number of patients sustaining conventional soft-tissue or crush injuries will benefit from burn center expertise. This study summarizes the current state of knowledge related to the management of terrorism mass casualty incidents caused by the use of conventional explosives. A review of pertinent medical, technical, and popular literature relating to terrorism and explosives, along with instruction received at Hadassah Hospital, Jerusalem, Israel on the management of mass casualty terrorism events was undertaken, and the pertinent medical and scientific literature relating to bomb delivery methods, blast mechanics, blast pathophysiology, and medical response to a terrorist bombing is presented here. Although terrorist use of chemical, radiological, or biological weapons is possible, historical analysis consistently demonstrates that the most likely terrorist weapon causing a mass casualty event is a standard explosive device detonated in a crowded area. The medical basis for management of such casualties is herein described.

Conventional terrorism and critical care

Incidents of conventional weapons terror are increasingly part of the reality of the modern world, and in Israel, 19,948 incidents have been reported from September 2000 to December 2003. Most victims are injured in explosions resulting from suicide bombings. Exposure to the blast (primary mechanism of injury) may produce unique injuries affecting gas-containing organs, including perforation of the eardrums (most common injury); pulmonary blast injury, characterized by alveolar capillary disruption and bronchopleural fistulas; and bowel perforation, which is uncommon and may be delayed from 1 to 14 days after the injury. However, most injuries are the result of penetrating trauma (secondary mechanism) resulting from bomb fragments and nails, bolts, and steel pellets embedded in the bomb striking the victim, and blunt trauma (tertiary mechanism) sustained when the victim is propelled against an object by the blast wind. The severity of the injuries is increased when the blast occurs in a confined space. Victims of terror-inflicted injuries have a high Injury Severity Score (30% >16), a high requirement for intensive care unit admission (22.8% in Israel), and have a more prolonged hospital course and higher mortality than victims of any other form of trauma.

Small-bowel adhesions long after blast injury

Images