Diagnosis of unsuspected facial fractures on routine head computerized tomographic scans in the unconscious multiply injured patient

PURPOSE

This article assessed the value of routine head computerized axial tomographic (CT) scans for diagnosis of unsuspected facial fractures and its clinical implications in the multiply injured patient who is intubated, unconscious, or sedated at the time of initial assessment and requires a head CT scan to assess for brain injury.

METHODS

At a level I trauma center from June 1, 1992 to June 1, 1993 all intubated blunt trauma patients who required routine CT scan evaluation at initial assessment were studied prospectively. Routine scanning started at the foramen magnum and included the maxilla. Patients who died within the first 24 hours were excluded.

RESULTS

The study population included 116 patients (85 male, 21 female) aged 12 to 85 years (mean, 28 years) with injury severity scores ranging from 1 to 50 (mean, 23). The mechanism of injury was: motor vehicle accidents (n = 74), motorcycling (n = 5), pedestrians accidents (n = 13), falls (n = 10), bicycling (n = 5), assaults (n = 8), and boating accident (n = 1). There were 19 suspected facial fractures; 18 required surgical repair. There were 27 unsuspected facial fractures; 13 required surgical care. Three suspected fractures were ruled out.

CONCLUSION

Routine head CT scans to assess for brain injury in the multiply injured patient are also very useful in the diagnosis of unsuspected facial fractures, almost half of which will require surgical intervention.

Elderly drivers involved in road crashes: a profile

The ability of elderly citizens to drive safely has been the subject of ongoing debate. To identify the type of elderly driver who becomes involved in an injury-producing road crash, we profiled all drivers over 39 years of age admitted to our Level I Trauma Center over a 1-year period. Data were prospectively collected and drivers age 40-59 years were compared with those over 60 years. Eighty-four drivers age > or = 60 and 130 drivers age 40-59 were studied. Of the 84 elderly drivers, 67 were deemed at fault. Twenty-four of those crashes were due to driving errors, 12 due to syncopes, and in 20 no crash cause was determined. Fifty-three of the 67 at fault drivers had significant underlying medical problems, compared to 9 of 17 deemed not at fault. Only four were legally intoxicated. Of the 130 drivers in the comparison group, only 19 had significant underlying medical problems; in three syncope was suspected; 18 were legally intoxicated. We conclude from our data that underlying medical disorders occur frequently in elderly drivers and may contribute to their incidence of road crashes.

The spectrum of blunt injury to the carotid artery: a multicenter perspective

The relative infrequency of blunt carotid artery trauma prompted a multicenter review to determine the spectrum of injuries, treatment strategies, and neurologic outcome. During a six-year period, 60 carotid artery injuries from blunt mechanisms in 49 patients were treated at 11 institutions. There were 11 bilateral injuries. Injury mechanisms were diverse but involved motor vehicles in 35 (72%) patients. In 14 (29%) patients, significant neurologic deficits developed more than 12 hours after a normal admission neurologic examination. The diagnosis was confirmed by angiography in 42 (86%). Duplex ultrasound accurately demonstrated the arterial injury in 12 (86%) of 14 patients. Documented injuries included arterial thrombosis in 20 arteries, arterial dissection alone in 19, dissection with pseudoaneurysm in six, pseudoaneurysm alone in five, frank arterial disruption in seven, and carotid-cavernous fistula in three. Arterial dissection was managed nonsurgically in 15 (79%) of 19 cases, the majority with systemic anticoagulation. Arterial thrombosis was managed with supportive therapy alone for 16 (80%) of 20 arteries; most associated with fixed neurologic deficits. Pseudoaneurysm repair was performed for six (55%) injuries. Carotid-cavernous fistulas were treated in all three instances with balloon occlusion. Overall mortality was 16 of 49 patients (43%). Good neurologic outcome was achieved in 22 (45%) patients. We conclude that: (1) Neurologic symptoms may develop in a delayed fashion; prior clinical suspicion and diagnostic testing are essential; (2) arterial dissection without complete occlusion may effectively be managed by anticoagulation; (3) pseudoaneurysms in accessible anatomic locations can be repaired with good results; and (4) injuries with complete arterial thrombosis are associated with high mortality and poor neurologic outcome in proportion to the initial degree of neurologic impairment.

Penetrating posterior abdominal trauma

Wounds of the back and flank pose a risk of injury to retroperitoneal structures which may be missed on physical examination. Recently, a selective approach to these wounds has been advocated. In order to document the incidence, management, and outcome of patients with penetrating wounds of the back and flank, we undertook a retrospective review of patients admitted over the past 5 years. Twenty-nine patients with penetrating posterior abdominal wounds were reviewed. There were 17 stab wounds and 12 gunshot wounds. All six patients who exhibited haemodynamic instability or abnormalities on physical examination underwent emergency laparotomy. The remaining 23 patients were admitted for observation. All patients underwent physical examination, abdominal radiographs, and urinalysis. Nine underwent IVP. Eight patients had abdominal CTs. No peritoneal lavages were performed. There were no missed injuries, no deaths and no delayed operations. There were two complications in the operative group, and one liver abscess in the nonoperative group. We conclude that selective management is a safe approach in penetrating posterior abdominal trauma without obvious indications for laparotomy.

In vivo association of Grb2 with pp116, a substrate of the T cell antigen receptor-activated protein tyrosine kinase

Numerous recent studies have implicated the src homology 2 and 3 domain-containing protein, Grb2, in coupling protein tyrosine kinase signaling pathways with the Ras signaling pathway. Ligation of the T cell antigen receptor results in the activation of both a PTK, and Ras; therefore, we investigated whether Grb2 may serve a similar function in T cells. Here we report that a GST/Grb2 fusion protein associates with several tyrosine phosphoproteins from lysates of T cell antigen receptor-stimulated Jurkat T cells. Two of these proteins, pp36 and pp116, bind to the Grb2 fusion protein with high affinity. Through the use of mutated Grb2 fusion proteins, we demonstrate that pp116 binds the amino-terminal src homology 3 domain of Grb2, the same domain of Grb2 thought to be primarily responsible for its interaction with SOS. We demonstrate further that pp116 associates with Grb2 in vivo, and we provide evidence that in the Jurkat T cell line Grb2 may exist complexed with either pp116 or with SOS.

The pivotal role of transesophageal echocardiography in the management of traumatic thoracic aortic rupture with associated intra-abdominal hemorrhage

Rupture of the thoracic aorta after blunt trauma, particularly when associated with multiple injuries, presents a major problem of resuscitation and management. Transesophageal color Doppler echocardiography (TEE) during laparotomy played a major role in confirming the diagnosis of thoracic aortic rupture in a patient.

The association between CD45 and lck does not require CD4 or CD8 and is independent of T cell receptor stimulation

CD45, the major transmembrane tyrosine phosphatase of lymphoid cells, is required for optimal signaling via a number of receptors. A model for how CD45 regulates signaling is that it controls phosphorylation of the COOH-terminal tyrosine of src family kinases. We have shown that CD45 physically associates with lck, one src kinase. Others have shown that CD45 also interacts with the CD4 and CD8 surface antigens expressed on many T cells. In this report we examine further the relationship between CD45 and lck in a CD4+ T cell line and in peripheral T cells. We show now that CD45 associates with lck independently of both CD4 and CD8. We show also the time course of an association between CD45 and a form of lck that migrates at an apparent higher molecular mass. Finally, we demonstrate that the interaction between CD45, lck, and a previously reported 32-34 kD protein is stable after stimulation of T cells.

Novel soluble, high-affinity gastrin-releasing peptide binding proteins in Swiss 3T3 fibroblasts

Swiss 3T3 cells contained substantial amounts of soluble and specific [125I]GRP binders. Like the membrane-associated GRP receptor, they were of high affinity, saturable, bound to GRP(14-27) affinity gels, and exhibited specificity for GRP(14-27) binding. They differed in that acid or freezing destroyed specific binding, specific binding exhibited different time and temperature effects, no detergent was required for their solubilization, ammonium sulfate fractionation yielded different profiles, the M(rs) were lower, GRP(1-16) also blocked binding, and a polyclonal anti-GRP receptor antiserum did not bind on Western blots. The isolated, soluble GRP binding protein(s) rapidly degraded [125I]GRP. These soluble GRP binding proteins may play a role in the regulation of the mitogenic effects of GRP on these cells.

Colostomy in trauma surgery: friend or foe?

Twenty-five patients underwent a colostomy that came to closure. There were eight blunt, 15 penetrating and two impaling injuries. Colostomy-related complications occurred in four patients; two wound infections, one stoma prolapse, one loop obstruction. Closure was performed during a second hospital stay after a standard mechanical bowel preparation and enteral and parenteral broad-spectrum antibiotics perioperatively. The procedure performed by board certified/eligible surgeons, lasted an average of 2.5-3h. Incisional hernias occurred as the only complication in two patients. For certain injuries of the colon, rectum and perineum, diverting colostomy is still the procedure of choice. It can be performed without significant additional morbidity. Subsequent closure in experienced hands does not carry a significant complication rate.

Complications of anticoagulation for pulmonary embolism in low risk trauma patients

Trauma patients are at significant risk for deep venous thrombosis (DVT) and pulmonary embolism (PE). Anticoagulation is standard therapy for DVT/PE, but may cause severe complications. We reviewed the course of 70 trauma ICU patients treated over a 28-month period. Thirty-six patients (51.4 percent) were treated by continuous IV heparin and/or oral warfarin. Of these, 13 patients (36 percent) developed complications requiring termination of anticoagulation. These included recurrent PE (four), subdural hematomas (three), hemothorax (two), heparin-induced thrombocytopenia (one), hemorrhagic pericardial effusion (one), retroperitoneal hematoma (one), and sudden unexplained drop in hemoglobin and shock (one). All patients with subdural hematomas had no prior evidence of head injury on brain computed tomography. All patients with recurrent PE received adequate anticoagulation therapy. Age > 55 was associated with increased risk of complications (8 of 13; p = .02:chi 2). Thirty-four other patients (48.6 percent) received inferior vena caval filters with no related complications or deaths. Anticoagulation for DVT/PE should be used selectively in trauma patients and avoided in elderly patients. Such patients should undergo early caval filter placement.

Limitations of neurological assessment in mild head injury

The authors have investigated two commonly used methods of assessing neurological status in patients with mild head injury to determine whether they can predict intracranial damage. Of 686 such patients with cranial computed tomography (CT) scans, scan results were recorded, along with total and motor components of the Glasgow Coma Scale (GCS) and the Reaction Level Scale (RLS85). Despite relatively normal admission neurological examinations, 127 of the 689 patients (18.4%) had intracranial lesions, and 38 (5.5%) required surgery. There was no significant difference in distribution of the GCS in patients with and without intracranial lesions. The RLS85 was superior to the GCS in predicting intracranial pathology, and a significant association between RLS85 and lesions on CT scanning was noted. However, even this test was normal in 19 patients found to have intracranial pathology, including nine who required surgery. The authors conclude that a normal or near-normal mental status examination in a head-injured patient on arrival at the emergency room is inadequate to exclude a potentially serious intracranial lesion. It is unlikely that further refinements in the clinical evaluation will result in diagnostic accuracy comparable with that of CT scanning. Accordingly, we recommend that any patient who has suffered a loss of consciousness or amnesia following head injury have an urgent cranial CT scan.

Failure of the legal system to enforce drunk driving legislation effectively

STUDY OBJECTIVE

To evaluate the investigation and prosecution of drunk drivers and identify reasons for system failure.

DESIGN

Prospective data collection on all drivers with an elevated blood alcohol level who were treated at a Level I trauma center between January 1 and June 30, 1991.

SETTING

Level I trauma center/university medical center serving a population of 1.8 million.

INTERVENTIONS

Prospective data collection, interviewing ambulance squad members, investigating police, and results of prosecution.

MEASUREMENTS AND MAIN RESULTS

Of 321 drivers, 78 had ethanol levels of more than 100 mg/dL; nine were between 50 and 100 mg/dL. All drivers had rapid transport to a trauma center for severe injury or high-risk injury mechanism. Police reports were accessible for 84 of 87 drivers; all drivers were believed to be at fault. The crashes resulted in five deaths and 74 other victims requiring hospitalization. Six of the intoxicated drivers died. Police requests for blood alcohol levels were made for 28 drivers, one of whom died. The remaining 59 drivers had no legal blood alcohol level drawn. Although the greater the distance from our center (more rural), the less likely were requests for ethanol levels, but there were many "no requests" from nearby cities. Of the 28 drivers on whom legal alcohol levels were drawn, eight escaped central registration with the highway safety commission, which records any and every traffic violation within New Jersey. Of the remaining 20, eight were not prosecuted (excluding one death), including one repeat offender. One committed a later "driving while intoxicated" offense and was then prosecuted. The remaining 11 were all convicted; five were repeat offenders.

CONCLUSION

Reasonable cause is required for legal blood alcohol requests. Our data demonstrated that this is difficult when the driver is unavailable for questioning. However, once legal blood alcohol levels have been obtained, inadequate legal follow-up leads to nonprosecution. Once officially charged, conviction appears certain, but even this punishment and re-education fail to change behavior in many of these drivers.

Interactions of mycoplasmas with B cells: antibody production and nonspecific effects

Interactions between mycoplasmas and B cells consist primarily of the development of specific antibody and of nonspecific interactions with B lymphocytes or antibody. Antibody responses are important in the resistance to mycoplasmal disease in both humans and animals. However, the ability of mycoplasmas to survive in their host despite vigorous responses suggests that these play a limited role in the host's recovery from infection. Antibody also may prevent dissemination of mycoplasmal infections from mucosal sites and may account for the appearance of systemic mycoplasmal infections in immunocompromised patients. In some cases, antibody responses may contribute to disease pathogenesis through the development of hypersensitivity responses or the deposition of immune complexes. In addition, nonspecific interactions between mycoplasmas and B lymphocytes have been implicated in disease pathogenesis, possibly leading to autoimmune reactions, modulation of immunity, and/or promotion of lesion development. For example, several mycoplasmas, including Mycoplasma pneumoniae and Mycoplasma pulmonis, are able to activate B cells polyclonally in vitro and in vivo, but the mechanisms and consequences of these responses have yet to be defined. In addition to activating B lymphocytes, mycoplasmas are capable of producing chemotactic factors, Fc receptors, and immunoglobulin proteases that may also be involved in lesion development and/or survival of the organisms. Thus, both specific and nonspecific interactions of mycoplasmas with B cells can have important effects on disease progression, especially since many mycoplasmal infections are chronic and the cumulative effect of these interactions may be substantial.

Rescue of signaling by a chimeric protein containing the cytoplasmic domain of CD45

Surface expression of the CD45 tyrosine phosphatase is essential for the T cell antigen receptor (TCR) to couple optimally with its second messenger pathways. CD45 may be required to dephosphorylate a TCR-activated protein tyrosine kinase, which then transduces an activation signal from the TCR. A chimeric molecule that contained extracellular and transmembrane sequences from an allele of a major histocompatibility class I molecule and cytoplasmic sequences of CD45 restored TCR signaling in a CD45-deficient mutant T cell line. Thus, expression of the complex extracellular domain of CD45 is not required for the TCR to couple to its signaling machinery.

Bacterial translocation occurs in humans after traumatic injury: evidence using immunofluorescence

We evaluated the occurrence of bacterial translocation (BT) in humans after traumatic injury. Twenty trauma patients (18 with blunt trauma) requiring celiotomy and without hollow viscus injury were studied. After surgical hemostasis and repair, portal venous blood (PVB) was sampled for culture. Additionally, a mesenteric lymph node (MLN) was harvested for culture and indirect immunofluorescence analysis using, first, mouse monoclonal antibody to E. coli beta-galactosidase, then goat anti-mouse immunoglobulin G (IgG). Injury Severity Score (ISS), Trauma Score (TS), and period of hemorrhagic shock (HS; systolic BP < 90 mm Hg with blood loss > 500 mL) were recorded before specimens were obtained.

RESULTS

Fifteen patients initially had HS (mean period of 60 minutes). Mean TS and ISS were 10 and 29, respectively. Seven patients did not have HS (mean TS and ISS, 10 and 13). Three patients received antibiotics preoperatively. Portal venous blood culture produced positive results in only three patients (two with HS) and culture of the MLN specimen was positive in one. However E. coli beta-galactosidase was detected within the cytoplasm of macrophages in all MLNs. One patient developed multiple organ failure.

CONCLUSION

Bacterial translocation occurs in humans following traumatic injury and may be independent of HS. Culture techniques may not detect BT since organisms may have been phagocytized by macrophages. The clinical significance of BT in trauma patients remains unclear.

Delayed and progressive brain injury in closed-head trauma: radiological demonstration

The importance of delayed or secondary brain insults in the eventual outcome of closed-head trauma has been documented in experimental models. To understand this phenomenon in the clinical setting, we studied a series of head-injured patients in whom multiple cranial computed tomographic (CT) scans were obtained. Patients whose follow-up CT studies revealed new intracranial lesions or worsening, compared with admission findings, were considered to have delayed cerebral injury. One hundred forty-nine (44.5%) of 337 consecutively studied patients developed delayed brain injury. There were highly significant associations (P < 0.001) between the appearance of delayed cerebral insults and the severity of the initial brain injury, the need for cardiopulmonary resuscitation in the field, the presence of coagulopathy at admission, and subdural hematoma on the initial CT scan. In addition, delayed injury was associated (P < 0.001) with higher mortality, slowed recovery, and poorer outcome at 6 months. Delayed brain injury was not significantly associated with patient age, sex, injury mechanism, associated injury, the need for endotracheal intubation in the field, early talking, CT abnormality other than intracranial hematoma, or type of residual neurological deficits. We used multiple regression analysis to explore the relationship between severity of injury, delayed insults, and outcome. As expected, the severity of the initial brain trauma contributed significantly to neurological outcome. The presence of delayed cerebral injury makes the outcome dramatically worse for each category of initial injury severity. The relationship between initial and secondary brain injury is discussed.

Continuous pulse oximetry and the diagnosis of pulmonary embolism in critically ill trauma patients

The diagnosis of pulmonary embolism (PE) may be difficult to establish in trauma patients, particularly those who are unresponsive or mechanically ventilated. Based on a prior retrospective study, we hypothesized that patients monitored by continuous pulse oximetry who experienced a 10% or greater sudden sustained drop in arterial oxygen saturation (SaO2) without a change in static lung compliance (Cst) were most likely to have had a PE. We followed SaO2 in 972 patients admitted to our trauma ICU during the 18-month period ending in December 1990. Forty-eight patients (5%) with SaO2 changes, but no Cst changes, were evaluated for suspected PE using pulmonary arteriography (PA). Of these, 21 (44%) had a positive PA study. All patients with a positive PA had either clear chest roentgenograms or no change in underlying pulmonary pathologic processes. Of the remainder, 26 had evidence of a new pathologic entity on chest roentgenograms and only one patient had a SaO2 decrease, no change in Cst, and a negative PA. All mechanically ventilated trauma patients should have SaO2 monitored continuously. Patients with a > 10% drop in Sao2 with no change in Cst and no new roentgenographic chest findings should undergo PA. Based on our experience, this approach would yield a sensitivity, specificity, and predictive value of 100%, 99.9%, and 95%, respectively, for the diagnosis of clinically significant PE.

Moderate head injury: a guide to initial management

The purpose of this study is to determine the initial treatment of patients who appear to have sustained moderate head injuries when first evaluated. The authors reviewed the records of 341 patients whose initial Glasgow Coma Scale (GCS) scores ranged from 9 to 12, as well as another 106 patients with GCS scores of 13. All patients underwent cranial computerized tomography (CT) at the time of admission. In 40.3% of these patients the CT scans were abnormal (30.6% had intracranial lesions), and 8.1% required neurosurgical intervention (craniotomies for hematoma in 12, elevation of depressed fractures in five, and insertion of intracranial pressure monitors in 19). Four patients died of their intracranial injuries. A similar incidence of lesions found on CT and at surgery suggests that an initial GCS score of 13 be classified with the moderate head injury group. Skull fractures were found to be poor indicators of intracranial abnormalities. These results suggest that all patients with head injury thought to be moderate on initial examination be admitted to the hospital and undergo urgent CT scanning. Patients with intracranial lesions require immediate neurosurgical consultation, surgery as needed, and admission to a critical-care unit. Scans should be repeated in patients whose recovery is less rapid than expected and in all patients with evidence of clinical deterioration; this was necessary in almost half of the patients in this group, and 32% were found to have progression of radiological abnormalities on serial CT scans.

Review article: venous thromboembolism in trauma patients

The increased coagulability in multiple injured patients results in increased risk for deep venous thrombosis and pulmonary embolism. The authors discuss etiology, diagnosis, treatment, and prophylaxis of venous thromboembolism in trauma patients.

Blunt colonic injury--a multicenter review

During the past decade there has been a shift in the management of injuries of the colon to primary repair without a protective diverting colostomy. Unfortunately, reports concerning this practice contain relatively few patients with blunt trauma and it is unclear whether the principles established for penetrating injury should be applied in the setting of blunt colon injury. A retrospective review of 54,361 major blunt trauma patients admitted to nine regional trauma centers from January 1, 1986, through December 31, 1990, was conducted. Statistical analysis of the data collected regarding 286 (0.5%) of these patients who suffered colonic injury revealed: (1) injury to the colon is found in more than 10% of patients undergoing laparotomy following blunt trauma; (2) available diagnostic modalities are unreliable in detecting isolated colonic pathology; (3) primary repair of full-thickness injuries or resection and anastomosis may be safely performed without diversion; (4) gross fecal contamination is the strongest contraindication to primary repair. Further, delay of surgery, shock, and the timing of antibiotic administration were not associated with significantly increased morbidity.