Predictors of initial management failure in traumatic hemothorax: A prospective multicenter cohort analysis.

BACKGROUND: Traumatic hemothorax is common, and management failure leads to worse outcomes. We sought to determine predictive factors and understand the role of trauma center performance in hemothorax management failure. METHODS: We prospectively examined initial hemothorax management (observation, pleural drainage, surgery) and failure requiring secondary intervention in 17 trauma centers. We defined hemothorax management failure requiring secondary intervention as thrombolytic administration, tube thoracostomy, image-guided drainage, or surgery after failure of the initial management strategy at the discretion of the treating trauma surgeon. Patient-level predictors of hemothorax management failure requiring secondary intervention were identified for 2 subgroups: initial observation and immediate pleural drainage. Trauma centers were divided into quartiles by hemothorax management failure requiring secondary intervention rate and hierarchical logistic regression quantified variation. RESULTS: Of 995 hemothoraces in 967 patients, 186 (19%) developed hemothorax management failure requiring secondary intervention. The frequency of hemothorax management failure requiring secondary intervention increased from observation to pleural drainage to surgical intervention (12%, 22%, and 35%, respectively). The number of ribs fractured (odds ratio 1.12 per fracture; 95% confidence interval 1.00-1.26) and pulmonary contusion (odds ratio 2.25, 95% confidence interval 1.03-4.91) predicted hemothorax management failure requiring secondary intervention in the observation subgroup, whereas chest injury severity (odds ratio 1.58; 95% confidence interval 1.17-2.12) and initial hemothorax volume evacuated (odds ratio 1.10 per 100 mL; 95% confidence interval 1.05-1.16) predicted hemothorax management failure requiring secondary intervention after pleural drainage. After adjusting for patient characteristics in the logistic regression model for hemothorax management failure requiring secondary intervention, patients treated at high hemothorax management failure requiring secondary intervention trauma centers were 6 times more likely to undergo an intervention after initial hemothorax management failure than patients treated in low hemothorax management failure requiring secondary intervention trauma centers (odds ratio 6.18, 95% confidence interval 3.41-11.21). CONCLUSION: Failure of initial management of traumatic hemothorax is common and highly variable across trauma centers. Assessing patient selection for a given management strategy and center-level practices represent opportunities to improve outcomes from traumatic hemothorax.

Predictors of retained hemothorax in trauma: Results of an Eastern Association for the Surgery of Trauma multi-institutional trial.

BACKGROUND: The natural history of traumatic hemothorax (HTX) remains unclear. We aimed to describe outcomes of HTX following tube thoracostomy drainage and to delineate factors that predict progression to a retained hemothorax (RH). We hypothesized that initial large-volume HTX predicts the development of an RH. METHODS: We conducted a prospective, observational, multi-institutional study of adult trauma patients diagnosed with an HTX identified on computed tomography (CT) scan with volumes calculated at time of diagnosis. All patients were managed with tube thoracostomy drainage within 24 hours of presentation. Retained hemothorax was defined as blood-density fluid identified on follow-up CT scan or need for additional intervention after initial tube thoracostomy placement for HTX. RESULTS: A total of 369 patients who presented with an HTX initially managed with tube thoracostomy drainage were enrolled from 17 trauma centers. Retained hemothorax was identified in 106 patients (28.7%). Patients with RH had a larger median (interquartile range) HTX volume on initial CT compared with no RH (191 [48-431] mL vs. 88 [35-245] mL, p = 0.013) and were more likely to be older with a higher burden of thoracic injury. After controlling for significant differences between groups, RH was independently associated with a larger HTX on presentation, with a 15% increase in risk of RH for each additional 100 mL of HTX on initial CT imaging (odds ratio, 1.15; 95% confidence interval, 1.08-1.21; p < 0.001). Patients with an RH also had higher rates of pneumonia and longer hospital length of stay than those with successful initial management. Retained hemothorax was also associated with worse functional outcomes at discharge and first outpatient follow-up. CONCLUSION: Larger initial HTX volumes are independently associated with RH, and unsuccessful initial management with tube thoracostomy is associated with worse patient outcomes. Future studies should use this experience to assess a range of options for reducing the risk of unsuccessful initial management. LEVEL OF EVIDENCE: Therapeutic/care management study, level III.

Fresh frozen plasma: red blood cells (1:2) coagulation effect is equivalent to 1:1 and whole blood.

BACKGROUND: Preemptive treatment of trauma-associated coagulopathy involves transfusion of fresh frozen plasma (FFP) at 1:1 ratio with red blood cells (RBCs), but the optimal ratio remains controversial. In combat theaters, fresh whole blood (FWB) is also an option. The objective of this study was to determine the effect of FFP:RBC ratios 1:1, 1:2, 1:3 and FWB on coagulation during resuscitation. MATERIALS AND METHODS: Thirty-six rats were randomized in the following six groups: Group 1: sham; Group 2: hemorrhage followed by sole lactated Ringer (LR) infusion; Group 3: FFP:RBC (1:1); Group 4: FFP:RBC (1:2); Group 5: FFP:RBC (1:3); Group 6: FWB transfusion. Another 25 animals were used for blood harvesting. Hemorrhage was induced by withdrawing 40% of total blood volume, mean arterial pressure (MAP) decreased to 45% of baseline, and laparotomy. Animals underwent LR infusion followed by blood product transfusion preset for each group. Blood samples were obtained at baseline and in the 105th minute for thromboelastometry and lactate. RESULTS: Hemorrhage caused a significant decrease in MAP and increase in lactate (P < 0.05). MAP was persistently low in group 2 despite fluid infusion (P < 0.05), but not in the other groups after 20 min of resuscitation. Mean clot formation time, alpha angle, and maximum clot firmness decreased significantly (P < 0.05) in group 2 (LR) and group 5 (1:3) compared with other groups. CONCLUSIONS: FFP:RBC in a 1:2 ratio optimally harnessed hemostatic resuscitation and prudent use of blood products compared with 1:1 and 1:3 ratios and to FWB transfusion.

Effects of Tityus serrulatus scorpion venom on thromboelastogram in rats.

Thromboelastometry was used to evaluate blood coagulation in anesthetized rats after intravenous administration of Tityus serrulatus scorpion venom (Tx). Tracheostomy followed by catheterization of the left jugular vein and right carotid artery were performed for Tx or Ringer's lactate solution injection and blood sample harvesting, respectively. Blood samples were obtained at the beginning of the experiments (baseline) and at two, five, 15, 30, and 60 min after intoxication. The following coagulation parameters were analyzed: CT (Clotting Time), CFT (Clotting Formation Time), Alpha Angle (α), MCF (Maximum Clot Firmness) and TPI (Thrombodynamic Potential Index). Toxin-induced hypercoagulability was demonstrated at the 15 and 60 min. We hypothesize Tx-induced hypercoagulability and enhanced clot formation could be explained by catecholamine release, systemic inflammatory response, and complement system activation, at least in the first hour after envenomation. Further studies are needed to determine the molecular mechanism of Tx-induced coagulopathy.

Gallstone ileus obstructing within an incarcerated lumbar hernia: an unusual presentation of a rare diagnosis.

We describe an unusual case of a 74-year-old woman who presented with signs and symptoms of small-bowel obstruction and a clinically appreciable, irreducible, left-sided lumbar hernia associated with previous iliac crest bone graft harvesting. Palpation of the hernia demonstrated a small, firm mass within the loops of herniated bowel. CT scanning recognised an intraluminal gallstone at the transition point, establishing the diagnosis of gallstone ileus within an incarcerated lumbar hernia. The proposed explanatory mechanism is that of a gallstone migrating into an easily reducible hernia containing small bowel causing obstruction at the hernia neck by a ball-valve mechanism, resulting in proximal bowel dilation and thus hernia incarceration; it remains unclear when the stone entered the hernia, and whether it enlarged in situ or prior to entering the enteral tract. This is only the second reported instance in the literature of an intraluminal gallstone causing hernia incarceration.

Vagus nerve stimulation improves coagulopathy in hemorrhagic shock: a thromboelastometric animal model study.

INTRODUCTION: Inflammation plays a major role in the multifactorial process of trauma associated coagulopathy. The vagus nerve regulates the cholinergic anti-inflammatory pathway. We hypothesized that efferent vagus nerve stimulation (VNS) can improve coagulopathy by modulating the inflammatory response to hemorrhage. METHODS: Wistar rats (n = 24) were divided in 3 groups: Group (G1) Sham hemorrhagic shock (HS); (G2) HS w/o VNS; (G3) HS followed by division of the vagus nerves and VNS of the distal stumps. Hemorrhage (45% of baseline MAPx15 minutes) was followed by normotensive resuscitation with LR. Vagus nerves were stimulated (3.5 mA, 5 Hz) for 30 sec 7 times. Samples were obtained at baseline and at 60 minutes for thromboelastometry (Rotem®) and cytokine assays (IL-1 and IL-10). ANOVA was used for statistical analysis; significance was set at p < 0.05. RESULTS: Maximum clot firmness (MCF) significantly decreased in G2 after HS (71.5 ± 1.5 vs. 64 ± 1.6) (p < 0.05). MCF significantly increased in G3 compared to baseline (67.3 ± 2.7 vs. 71.5 ± 1.2) (p < 0.05). G3 also showed significant improvement in Alfa angle, and Clot Formation Time (CFT) compared to baseline. IL-1 increased significantly in group 2 and decrease in group 3, while IL-10 increased in group 3 (p < 0.05). CONCLUSIONS: Electrical stimulation of efferent vagus nerves, during resuscitation (G3), decreases inflammatory response to hemorrhage and improves coagulation.

Abdominal catastrophes in the intensive care unit setting.

Patients in the setting of the intensive care unit can develop intra-abdominal complications that may worsen outcome. Clinical suspicion of such complications coupled with early diagnosis and treatment may reduce morbidity and mortality associated with these processes. This article addresses the diagnosis and management of some of the common causes of intra-abdominal catastrophes.

Permissive hypotension does not reduce regional organ perfusion compared to normotensive resuscitation: animal study with fluorescent microspheres.

INTRODUCTION: The objective of this study was to investigate regional organ perfusion acutely following uncontrolled hemorrhage in an animal model that simulates a penetrating vascular injury and accounts for prehospital times in urban trauma. We set forth to determine if hypotensive resuscitation (permissive hypotension) would result in equivalent organ perfusion compared to normotensive resuscitation. METHODS: Twenty four (n=24) male rats randomized to 4 groups: Sham, No Fluid (NF), Permissive Hypotension (PH) (60% of baseline mean arterial pressure - MAP), Normotensive Resuscitation (NBP). Uncontrolled hemorrhage caused by a standardised injury to the abdominal aorta; MAP was monitored continuously and lactated Ringer's was infused. Fluorimeter readings of regional blood flow of the brain, heart, lung, kidney, liver, and bowel were obtained at baseline and 85 minutes after hemorrhage, as well as, cardiac output, lactic acid, and laboratory tests; intra-abdominal blood loss was assessed. Analysis of variance was used for comparison. RESULTS: Intra-abdominal blood loss was higher in NBP group, as well as, lower hematocrit and hemoglobin levels. No statistical differences in perfusion of any organ between PH and NBP groups. No statistical difference in cardiac output between PH and NBP groups, as well as, in lactic acid levels between PH and NBP. NF group had significantly higher lactic acidosis and had significantly lower organ perfusion. CONCLUSIONS: Hypotensive resuscitation causes less intra-abdominal bleeding than normotensive resuscitation and concurrently maintains equivalent organ perfusion. No fluid resuscitation reduces intra-abdominal bleeding but also significantly reduces organ perfusion.

A technical modification for percutaneous tracheostomy: prospective case series study on one hundred patients.

The purpose of this study is to describe a technical modification of percutaneous tracheostomy that combines principles of the Percu Twist™ and the Griggs-Portex® methods in a reusable kit. One hundred patients underwent the procedure. There were no false passage, tube misplacement, or deaths related to the procedure. There were two minor bleedings managed conservatively. The technical modification described in this study is safe and simple to execute.

The natural history of trauma-related coagulopathy: implications for treatment.

BACKGROUND: Hemorrhage is a leading cause of death in trauma patients and coagulopathy is a significant contributor. Although the exact mechanisms of trauma-associated coagulopathy (TAC) are incompletely understood, hemostatic resuscitation strategies have been developed to treat TAC. Our study sought to identify which trauma patients develop TAC and the factors associated with its development, to describe the natural history of TAC, and to identify patients with TAC who may not require hemostatic resuscitation. METHODS: Patients with early coagulopathy (International Normalized Ratio >1.3) who were admitted directly from the scene within 1 hour of injury were identified in our institutional trauma registry. We analyzed these data for the presence of TAC, predictors of early and delayed TAC, and evolution of TAC during the first 24 hours of admission. RESULTS: Of 2,473 patients, 290 (12%) had early TAC (International Normalized Ratio >1.3) and 271 (11%) developed delayed TAC. Multivariate analysis identified female gender (odds ratio [OR] 1.25 [1.11-1.41]), lower pH (OR 0.08 [0.015-0.47]), lower hemoglobin (OR 0.96 [0.95-0.97]), lower temperature (OR 0.82 [0.70-0.95]), and blunt mechanism (OR 0.49 [0.33-0.71]) as factors significantly associated with development of early TAC. Progression of early TAC occurred in 64%, and these patients had more severe abdominal injury and received more emergency room crystalloid. Of patients with early TAC who did not receive fresh frozen plasma, only 49% developed worsening coagulopathy. Patients with isolated intracranial hemorrhage had higher rates of bleeding progression (75% vs. 20%, p < 0.005) in the presence of early TAC. CONCLUSIONS: TAC may appear in an early or delayed form and its presence and progression are associated with a number of identifiable factors. Although TAC commonly progresses, it also resolves spontaneously in many patients. Further research is required to identify which patients with TAC require hemostatic treatment, although those with intracranial hemorrhages seem to warrant aggressive therapy.

Permissive hypotension and desmopressin enhance clot formation.

BACKGROUND: Experimental studies of uncontrolled hemorrhage demonstrated that permissive hypotension (PH) reduces blood loss, but its effect on clot formation remains unexplored. Desmopressin (DDAVP) enhances platelet adhesion promoting stronger clots. We hypothesized PH and DDAVP have additive effects and reduce bleeding in uncontrolled hemorrhage. METHODS: Rabbits (n = 42) randomized as follows: sham; normal blood pressure (NBP) resuscitation; PH resuscitation-60% baseline mean arterial pressure; NBP plus DDAVP 1 hour before (DDAVP NBP) or 15 minutes after beginning of shock (DDAVP T1 NBP); and PH plus DDAVP 1 hour before (DDAVP PH) or 15 minutes after beginning of shock (DDAVP T1 PH). Fluid resuscitation started 15 minutes after aortic injury and ended at 85 minutes. Intraabdominal blood loss was calculated, aortic clot sent for electron microscopy. Activated partial thromboplastin time, platelet count, thromboelastometry, arterial blood gases, and complete blood count were performed at baseline and 85 minutes. Analysis of variance was used for comparison. RESULTS: NBP received more fluid volume and had greater intraabdominal blood loss. DDAVP, when administered preshock, significantly reduced blood loss in NBP and fluid requirement when given postshock. Platelets, arterial blood gas, complete blood count, and activated partial thromboplastin time were similar at 85 minutes. NBP delayed clot formation and worsened thrombodynamic potential on thromboelastometry, whereas PH and DDAVP improved. Electron microscopy showed lack of fibrin on NBP clots, whereas DDAVP and PH clots displayed exuberant fibrin/platelet aggregates. DDAVP NBP presented intermediate clots. CONCLUSION: PH reduced bleeding and improved hemostasis compared with normotensive resuscitation. DDAVP given preshock exerted similar effects with normotensive resuscitation.

Cobertura temporária da cavidade abdominal com curativo a vácuo / Vacuum pack technique for temporary abdominal wound closure

OBJETIVO: Descrever técnica de curativo para cobertura temporária da cavidade abdominal que utiliza sistema de vácuo. MÉTODO: A técnica foi aplicada em 12 pacientes. Inicialmente coloca-se sobre a laparostomia a bolsa plástica fenestrada, em seguida a primeira camada de compressas. Sobre esta, coloca-se o tubo de látex. Este é recoberto por outra camada de compressas as quais são fixadas sobre o curativo com o campo cirúrgico auto-aderente. O tubo de látex é conectado ao sistema de vácuo com pressão de -10 a -50 mmHg. Trocam-se os curativos a cada 12 horas. Material utilizado bolsa plástica de solução salina, compressas cirúrgicas, tubo de látex, campo cirúrgico auto-aderente de 50cm x 30cm e vácuo do sistema de gases hospitalares. RESULTADOS:A peritonite grave foi a indicação mais freqüente para laparostomia, seguida da síndrome de compartimento abdominal. Fechamento definitivo da cavidade abdominal foi possível em oito pacientes (67 por cento) em média após 11 dias (9 a 21 dias) da laparostomia. Não houve complicações associadas ao método. O custo diário aproximado do curativo foi de R$ 50,00. CONCLUSÃO: O curativo a vácuo proporcionou boa contenção das vísceras abdominais, controlou o extravasamento de secreções e o edema. Permitiu o fechamento definitivo da cavidade abdominal na maioria dos casos e foi de baixo custo.

BACKGROUND: We describe a vacuum pack technique for a temporary abdominal wound closure. METHODS: The vacuum pack materials were a plastic sheet, laparotomy pads, latex tube, 50cm x 30cm adhesive-backed plastic, and a vacuum source. Twelve patients underwent the procedure as follows: we cut several slits in the plastic sheet, which is applied directly over the abdominal contents. We put laparotomy pads over the plastic sheet, and then a latex tube is placed over the laparotomy pads. Another layer of laparotomy pads is placed over the latex tube, which is stuck by an adhesive-backed plastic. We connect the tube to a vacuum source with negative pressure between -10 to -50 mmHg. The pack is changed every 12 hours. RESULTS: Severe peritonitis was the most common indication followed by the abdominal compartment syndrome. Definitive abdominal closure was performed in eight patients (67 percent) after an average of 11 days (9 to 21 days) from the first day of laparostomy. There were no complications directly associated with the method. Daily cost was approximately R$ 50.00. CONCLUSION: The vacuum pack kept the underlying abdominal viscera secure beneath the dressing; in addition, it controlled fluid leakage and edema. Definitive abdominal wound closure was possible in the majority of the patients. This was achieved at a reasonable financial cost.

The abdominal compartment syndrome as a second insult during systemic neutrophil priming provokes multiple organ injury.

In our recent clinical study of damage control laparotomy, the abdominal compartment syndrome (ACS) emerged as an independent risk factor for postinjury multiple organ failure (MOF). We and others have shown previously that the ACS promotes the systemic production of proinflammatory cytokines. Our study objective was to develop a clinically relevant two-event animal model of postinjury MOF using the ACS as a second insult during systemic neutrophil priming to provoke organ dysfunction. Male adult rats underwent hemorrhagic shock (30 mmHg x 45 min) and were resuscitated with crystalloids and shed blood. The timing of postshock systemic neutrophil (PMN) priming was determined by the surface expression of CD11b via flow cytometry. Finding maximal PMN priming at 8 h, but no priming at 2 h (early) and 18 h (late), the ACS (25 mmHg x 60 min) was introduced at these time points. At 24 h postshock, lung injury was assessed by lung elastase concentration and Evans blue dye extravasation in bronchoalveolar lavage. Liver and renal injuries were determined by serum alanine aminotransferase, serum creatinine, and blood urea nitrogen. The ACS during the time of maximal systemic PMN priming (8 h) provoked lung and liver injury, but did not if introduced at 2 or 18 h postshock when there was no evidence of systemic PMN priming. The 24-h mortality of this two-event model was 33%. These findings corroborate the potential for the ACS to promote multiple organ injury when occurring at the time of systemic PMN priming. This clinically relevant two-event animal model of PMN organ injury may be useful in elucidating therapy strategies to prevent postinjury MOF.

Systemic inflammatory response secondary to abdominal compartment syndrome: stage for multiple organ failure.

BACKGROUND: The abdominal compartment syndrome (ACS) has been implicated in the pathogenesis of postinjury multiple organ failure. The ACS is defined as intra-abdominal hypertension causing adverse physiologic response. This study was designed to determine the effects of IAH on the production of interleukin-1b (IL-1beta), interleukin-6 (IL-6), tumor necrosis factor (TNF-alpha), and the effects on remote organ injury. METHODS: IAH was induced in Sprague-Dawley rats which were divided into 5 groups, 10 animals each. Intra-abdominal pressure (IAP) was increased to 20 mm Hg for 60 and 90 minutes in two different groups. In a third group following IAP of 20 mm Hg the abdomen was decompressed for 30 minutes before samples were collected. The other animals were used as controls. Hemodynamic response was monitored throughout the procedure. Cytokine levels were assessed in the plasma. Remote organ injury was assessed by histopathology and myeloperoxidase activity. RESULTS: IAH caused a significant decrease in MAP. After abdominal decompression MAP returned to baseline levels. A significant decrease in arterial pH was also noted. Increase in the levels of TNF-alpha and IL-6 was noted 30 minutes after abdominal decompression. Plasma concentration of IL-1b was elevated after 60 minutes of IAH. Abdominal decompression, however, did not cause a significant increase in the levels of this cytokine. Lung neutrophil accumulation was significantly elevated only after abdominal decompression. Histopathological findings showed intense pulmonary inflammatory infiltration including atelectasis and alveolar edema. CONCLUSIONS: IAH provokes the release of pro-inflammatory cytokines which may serve as a second insult for the induction of MOF.