Damage control surgery in lung trauma

Damage control techniques applied to the management of thoracic injuries have evolved over the last 15 years. Despite the limited number of publications, information is sufficient to scatter some fears and establish management principles. The severity of the anatomical injury justifies the procedure of damage control in only few selected cases. In most cases, the magnitude of the physiological derangement and the presence of other sources of bleeding within the thoracic cavity or in other body compartments constitutes the indication for the abbreviated procedure. The classification of lung injuries as peripheral, transfixing, and central or multiple, provides a guideline for the transient bleeding control and for the definitive management of the injury: pneumorraphy, wedge resection, tractotomy or anatomical resection, respectively. Identification of specific patterns such as the need for resuscitative thoracotomy, or aortic occlusion, the existence of massive hemothorax, a central lung injury, a tracheobronchial injury, a major vascular injury, multiple bleeding sites as well as the recognition of hypothermia, acidosis or coagulopathy, constitute the indication for a damage control thoracotomy. In these cases, the surgeon executes an abbreviated procedure with packing of the bleeding surfaces, primary management with packing of some selected peripheral or transfixing lung injuries, and the postponement of lung resection, clamping of the pulmonary hilum in the most selective way possible. The abbreviation of the thoracotomy closure is achieved by suturing the skin over the wound packed, or by installing a vacuum system. The management of the patient in the intensive care unit will allow identification of those who require urgent reintervention and the correction of the physiological derangement in the remaining patients for their scheduled reintervention and definitive management.

Ventilation-induced epithelial injury drives biological onset of lung trauma in vitro and is mitigated with anti-inflammatory therapeutics

Mortality rates among patients suffering from acute respiratory failure remain perplexingly high despite maintenance of blood homeostasis. The biotrauma hypothesis advances that mechanical forces from invasive ventilation trigger immunological factors that spread systemically. Yet, how these forces elicit an immune response remains unclear. Here we show that flow-induced stresses under mechanical ventilation can injure the bronchial epithelium of ventilated in vitro upper airway models and directly modulate inflammatory cytokine secretion associated with pulmonary injury. We identify site-specific susceptibility to epithelial erosion in airways from jet-flow impaction and measure an increase in cell apoptosis and modulated secretions of cytokines IL-6, 8 and 10. We find that prophylactic pharmacological treatment with anti-inflammatory therapeutics reduces apoptosis and pro-inflammatory signaling during ventilation. Our 3D in vitro airway platform points to a previously overlooked origin of lung injury and showcases translational opportunities in preclinical pulmonary research towards protective therapies and improved protocols for patient care.

A clinical series of packing the wound tract for arresting traumatic hemorrhage from injuries of the lung parenchyma as a feasible damage control technique

Background Tractotomy has become the standard of care for transfixing through-and-through lung injuries as it can be performed quickly with little blood loss and a low risk of complications. However, packing with laparotomy pads could be a feasible alternative to tractotomy on selected patients. We describe a series of four patients with lung trauma in which packing of the pulmonary wound tract was used as the primary and unique surgical strategy for arresting hemorrhage from injuries of the lung parenchyma. Methods Packing of the traumatic tract is achieved by gently pulling a laparotomy pad with a Rochester clamp and adjusting it to the cavity to stop the bleeding. The pack is removed in a subsequent surgery by moistening and tractioning it softly to avoid additional damage. The operation is completed by manual compression of the wounded lobe. We present a case series of our experience with this approach. Results From 2012 to 2016, we treated four patients with the described method. The mechanism was penetrating in all them. The clinical condition was of exsanguinations with multiple sources of hemorrhage. There were three patients with peripheral injuries to the lung and one with a central injury to the pulmonary parenchyma. Bleeding was stopped in all the cases. Three patients survived. A patient had recurrent pneumothorax which was resolved with a second chest tube. Conclusion Packing of the traumatic tract allowed rapid and safe treatment of transfixing through-and-through pulmonary wounds in exsanguinating patients under damage control from several bleeding sources.

Influence of Expertise on Perception and Understanding on Viewing a Molecular Animation of the Lung Endothelial Surface Layer and its Role in Inflammation

At the University of Illinois College of Medicine Anesthesiology Research department, lung trauma researchers aimed to generate interest in the importance of the lung endothelial surface layer in inflammation. However, they had difficulty describing the dynamic molecular structure of the lung endothelial surface layer and its role in inflammatory processes in the lung. A 3D animation was created because of its ability to communicate a rich and complex molecular narrative. Prior studies have shown that, for scientific animations, level of expertise of the viewer influences how an animation is perceived. This study aimed to improve lung trauma researchers’ ability to generate interest in their research and to assess if prior knowledge affects how biomedical animations are perceived in terms of engagement by analyzing eye-tracking.

New Ventilator Strategies: High-Frequency Oscillatory Ventilation Combined with Volume Guarantee

High-frequency oscillatory ventilation (HFOV) has been proposed as an alternative method of invasive ventilation in immature infants to prevent ventilator lung injury. To better control the size of the high-frequency tidal volume and to prevent large tidal volumes, a new strategy of controlling the tidal volume during HFOV (VThf) has been developed, HFOV–volume guarantee (VG). Data from preclinical, neonatal animal studies in normal and surfactant-depleted lungs have demonstrated the feasibility of this technique to directly control the VThf in the normal compliance and low compliance situations. Different I:E ratios also can modify the effect of CO2 washout during HFOV combined with VG in a different way as without the VG modality. Finally, clinical use of this technique in newborn infants has demonstrated the possibility of using very high frequency combined with constant very low VThf to decrease the risk of lung trauma related to the ventilator.

Preliminary Investigation of the Mechanics of a Novel Thoracic Cavity Extra Pulmonary Oxygenation Device

Acute respiratory distress syndrome (ARDS) arising from trauma, sepsis, pneumonia or other diseases has been acknowledged to be a major clinical problem in respiratory medicine. Hypoxia and hypercapnia arising from ARDS are life-threating particularly in children and elderly people. The reported mortality rate for ARDS is high. Current methods for treating patients who have limited or no lung function are ineffective or insufficient and present additional risks to the patients. In this research, we have explored new methods of infusing phospholipid-coated oxygen microbubbles (OMBs) to the thoracic cavity in order to oxygenate patients suffering from ARDS and hypoxemia. In our previous work, OMBs have been shown to be effective in treating hypoxia in models of LPS lung injury and lung trauma in rats and rabbits. In this study, we have developed a novel thoracic cavity extrapulmonary oxygenation devices using OMBs and test this device in a benchtop test and in vivo experiment on a large animal (pig) right pneumothorax injury model.