Biomedical subjects
Publications and source records attributed to D Demetriades.
This article discusses the problems and controversies in the assessment of penetrating injuries of the neck. The role of physical examination and color-flow Doppler imaging in the initial assessment is highlighted. Complex injuries of major vessels, the aerodigestive tract, and the parotid are discussed and therapeutic options are presented.
The proposed noninvasive monitoring systems provide the essential hemodynamic and oxygen transport information previously available only by invasive thermodilution catheters. More importantly, the noninvasive systems provide continuous on-line real-time displays of data which allow immediate recognition of circulatory abnormalities and provide a means to titrate therapy to appropriate therapeutic goals. The noninvasive systems are easy to apply, safe, inexpensive, and more cost-effective than invasive monitoring.
BACKGROUND: It has been suggested that all transcervical gunshot wounds should be explored surgically because of the high incidence of injuries to vital structures. The present prospective study investigated the clinical presentation, the role of various diagnostic investigations, and the need for surgery in patients with transcervical gunshot injuries. METHODS: Ninety-seven patients sustained gunshot injuries to the neck and 33 of them (34%) were transcervical. All victims were assessed clinically according to a written protocol and subsequently were evaluated angiographically, and, in the appropriate case, by means of endoscopy and esophagography. RESULTS: Overall, 24 (73%) of the 33 patients with transcervical gunshot wounds had injuries to cervical structures. Vascular injuries were found in 48%, spinal cord injuries in 24%, and aerodigestive tract injuries in 6% of patients with transcervical injuries. In the 64 patients without midline crossing, the incidence of cervical structure injuries was 31%. Despite the high incidence of injuries to cervical structures in transcervical wounds, only 21% of the patients had a therapeutic operation. The overall mortality was 3%. There were no in-hospital deaths or local complications in the nonoperatively managed group. CONCLUSIONS: The results of the present study do not support the current recommendations of mandatory operation for all transcervical gunshot wounds. A careful clinical examination combined with the appropriate diagnostic investigations should determine the treatment modality. About 80% of these patients can safely be managed nonoperatively.
PURPOSE: This study was designed to investigate the epidemiology and prognostic factors determining survival in penetrating injuries of the aorta. PATIENTS AND METHODS: This was a retrospective analysis of all patients with penetrating aortic injuries, admitted to a large, level I trauma center. The following factors were analyzed for their role in determining survival: mechanism of injury, anatomical site of the aortic injury, initial blood pressure on admission, need for emergency room thoracotomy, and the introduction of a dedicated trauma program with an attending surgeon in-house. RESULTS: There were 93 patients with penetrating aortic injuries over a 5-year period. The abdominal aorta was injured in 67 patients (72%) and the thoracic aorta in 26 (28%). Most of the victims (82.5%) were admitted in shock and 41% had an unrecordable blood pressure on admission. Victims with injury to the thoracic aorta were more likely to have an unrecordable blood pressure on admission than patients with abdominal aortic injuries (73% vs 28.4%), and more likely to require an emergency room thoracotomy (76.9% vs 20.9%). Thirty-four patients (36.6%) required an emergency room thoracotomy and there were no survivors. The overall mortality was 80.6% (87.5% for gunshot injuries, 64.7 % for knife injuries). Patients with abdominal aortic injuries were three times more likely to survive than those with thoracic aortic injuries (23.9% vs 7.7%). The introduction of a dedicated trauma program, which resulted in significant reduction of mortality in other types of severe trauma, had no effect on the outcome in aortic injuries. CONCLUSIONS: Penetrating aortic injuries still have a very high mortality rate with no improvement in survival despite improved trauma services. Injury to the thoracic aorta, gunshot wounds, unrecordable blood pressure on admission, and the need for emergency room thoracotomy, are important predictors of high mortality.
OBJECTIVE: To evaluate the hypothesis that alert nonintoxicated trauma patients with negative clinical examinations are at no risk of cervical spine injury and do not need any radiographic investigation. DESIGN: Prospective study. SETTING: A university-affiliated teaching county hospital. PATIENTS: Five hundred and forty-nine consecutive alert, oriented, and clinically nonintoxicated blunt trauma victims with no neck symptoms. RESULTS: All patients had negative clinical neck examinations. After radiographic assessment, no cervical spine injuries were identified. Less than half the patients could be evaluated adequately with the three standard initial views (anteroposterior, lateral, and odontoid). All the rest needed more radiographs and/or computed tomographic scans. A total of 2,27 cervical spine radiographs, 78 computed tomographic scans and magnetic resonance imagings were performed. Seventeen patients stayed one day in the hospital for no other reason but radiographic clearance of an asymptomatic neck. The total cost for x-rays and extra hospital days was $242,000. These patients stayed in the collar for an average of 3.3 hours (range, 0.5-72 hours). There was never an injury missed. CONCLUSIONS: Clinical examination alone can reliably assess all blunt trauma patients who are alert, nonintoxicated, and report no neck symptoms. In the absence of any palpation or motion neck tenderness during examination, the patient may be released from cervical spine precautions without any radiographic investigations.
Explore the source record for details and available documents.
The aim of our study was to describe the characteristics of Xanthomonas infections in a population of critically ill surgical patients. The clinical records and microbiological data on 93 patients in a surgical intensive care unit (SICU) developing Xanthomonas infections were reviewed. Xanthomonas was isolated in 125 sites in the 93 patients. Their average age was 48 years (range, 14-94). Mortality occurred in 25 patients (26.9%) versus 10.3 per cent of SICU patients in general (P < 0.05). Patients were in the SICU for an average of 11.9 days before developing a positive Xanthomonas culture, and 87 per cent (81/93) of patients developed an infection at some other site before isolation of Xanthomonas. Trimethoprim sulfamethoxazole was the only drug to which the isolates were commonly sensitive (123/125 = 98.4%). We conclude that Xanthomonas 1) is associated with increased mortality; 2) is resistant to many of the drugs that usually cover Gram-negative infections; and 3) commonly complicates a prolonged intensive care stay, thus serving as a marker for severity of illness.
The aim of the present study was to explore methods, concepts, and techniques that provide recognition of circulatory deficiencies at the earliest possible time in the patient's illness. We used both the standard invasive pulmonary artery thermodilution catheter and noninvasive hemodynamic monitoring systems consisting of a new bioimpedance cardiac output device, pulse oximetry, transcutaneous oxygen (PtCO2) and carbon dioxide tensions as well as the transcutaneous oxygen tension/fraction of inspired oxygen ratio (PtCO2/FIO2). These three noninvasive systems were used to evaluate cardiac function, pulmonary function, and tissue perfusion, respectively. This approach to early noninvasive monitoring is based on recent evidence suggesting that poor tissue perfusion and oxygenation initiate circulatory dysfunction that leads to shock and organ failure. We studied 303 acute episodes of circulatory dysfunction and shock in 261 patients in a university-run county hospital; 75 were acute traumatic injuries and 109 acute nontrauma medical emergencies on admission to the emergency department, and 77 ICU patients with an acute illness or exacerbation of their current illness. The study was a prospective, descriptive study to identify early abnormal circulatory patterns reflecting the cardiac, pulmonary, and perfusion functions associated with death and with survival. We described noninvasively monitored patterns in individual illustrative cases, in common etiologic groups, and in physiologic categories representing various abnormal functional patterns. We found that hypotensive shock usually was preceded by episodes of high flow followed by low flow and inadequate tissue perfusion indicated by reduced PtCO2; this frequent pattern was modified by associated co-morbid conditions, especially hypovolemia, limited cardiac reserve capacity, age, hypertensive states, and increased body metabolism from infection, trauma, stress, exercise, temperature, and endocrine disorders. Reduced pulmonary function occurred in 18% of emergency patients; these were usually patients with thoracic trauma, severe hypovolemia, head injuries, chronic obstructive pulmonary disease, asthma, drug overdose, and central nervous system failure (massive stroke and coma). We concluded that noninvasive measurements identify early circulatory problems reliably and provide objective criteria for physiologic analysis as well as for definition of therapeutic goals and titration of therapy.
Large databases allow for rapid access to large volumes of data. To convert raw data to information, large numbers of data points must be correlated into a descriptive pattern that can be interpreted by the user. Databases must be constructed so as to allow reliable extraction of the raw data into a format that supports analysis of events in a meaningful, objective, and reproducible manner. Databases must be responsive to a variety of users. They must not demand unrealistic amounts of effort on those responsible for data entry. Standard protocols in various stages of development will make databases easier to use and more reliable. Database management tools such as the Internet and the National Library of Medicine will become more integrated into the practice of critical care medicine at all levels, including administration, clinical care, and research. This article provides an overview of the capabilities and difficulties associated with large databases. The major areas of use of large databases in the hospital setting are administration, bibliographic, patient care, research, and education. Each of these areas has different requirements and is supported by different types of databases. The advantages and disadvantages of linear, relational, and object-oriented databases are discussed. Issues relating to methods of data entry and the accuracy and reliability of data are discussed. The challenges involving integration of various sources of data and the interfacing of devices are reviewed.
BACKGROUND: In recent years, many trauma centers have been closing or scaling down their operations because of financial losses and lack of commitment by the relevant authorities. OBJECTIVE: To investigate the effect of commitment to trauma and the establishment of a dedicated trauma program on injury outcome. DESIGN: In 1992, a well-funded dedicated trauma program was implemented at the Los Angeles County--University of Southern California Medical Center, Los Angeles. We analyzed the outcome in severely injured patients (Injury Severity Score [ISS] > 15) before and after implementation of the program (1991 and 1993). SETTING: Large, urban, level 1 trauma center. PATIENTS: Patients with trauma and an ISS higher than 15. RESULTS: There were 737 patients with an ISS higher than 15 in 1991 and 812 patients with an ISS higher than 15 in 1993. The overall mortality rate was 30% in 1991 and 24.5% in 1993 (P = .018), which is a reduction by 18.3%. In patients with blunt trauma and an ISS higher than 15, mortality was reduced by 33% (mortality rate of 31.1% in 1991 vs 20.8% in 1993) (P < .002). Mortality in patients with penetrating trauma and an ISS higher than 30 was reduced by 42.7% (mortality rate of 59.3% in 1991 vs 34% in 1993) (P = .019). There was also a trend toward lower permanent disabilities among survivors with an ISS higher than 15 (14.7% in 1991 vs 11.3% in 1993). CONCLUSION: Commitment of financial and human resources for the establishment of a dedicated trauma program is a sound investment in terms of improved survival and fewer permanent disabilities in critically injured patients.
BACKGROUND: The initial assessment of penetrating injuries of the neck is controversial, with angiography remaining the gold standard for identifying vascular injuries. Recent reports suggest that physical examination might be an accurate way to evaluate these injuries. Color flow Doppler imaging has been used with promising results to assess extremity injuries, but the role of color flow Doppler imaging in neck injuries has not been studied. OBJECTIVE: To evaluate and compare the roles of physical examination, color flow Doppler imaging, and angiography in the identification and management of penetrating neck injuries. STUDY DESIGN: A prospective study of patients in stable condition with penetrating injuries of the neck. All study patients were examined according to a written clinical protocol and subsequently underwent angiography and color flow Doppler imaging. The sensitivity and specificity of physical examination and color flow Doppler imaging were compared with those of angiography. RESULTS: Eighty-two patients fulfilled the criteria for inclusion in the study. Angiography demonstrated vascular lesions in 11 patients (13.4%), but only two (2.4%) of them required treatment. Serious injuries were detected or suspected during physical examination, but six lesions not requiring treatment were missed. When injuries not requiring treatment were excluded, the sensitivity was 100% and the specificity was 91%. With color flow Doppler imaging, 10 of the 11 injuries were identified, for a sensitivity of 91% and a specificity of 98.6%. The sensitivity and specificity were 100% for clinically important lesions. CONCLUSION: The combination of a careful physical examination and color flow Doppler imaging provides a reliable way to assess penetrating neck trauma and may be a safe alternative to routine contrast angiography.
We report the cases of two patients who developed aortoesophageal fistulae after sustaining gunshot wounds to the chest. One suddenly exsanguinated 5 hours postinjury while in the angiography suite. The other manifested 4 weeks postinjury while in a rehabilitation hospital for associated spinal cord injury. The diagnosis and management were complicated, but the patient lived. He is the only survivor of aortoesophageal fistula due to gunshot wound that we could find in the literature.
The clinical experience with gunshot injuries to the thoracic aorta at a large urban trauma center was reviewed. Of 1961 patients admitted with gunshot wounds to the chest, 20 sustained injuries to the thoracic aorta. Mortality occurred in 17 patients (85%), all of whom were hypotensive or moribund upon admission. The three patients (15%) presenting with a systolic blood pressure above 100 mm Hg survived; only one of these underwent surgery during the acute period. Only two patients were stable enough for aortography. Advances in the management of critically injured patients have not improved the outcome with this lethal injury.
There continues to be difficulty making the clinical distinction between fungal colonization and systemic infection in critically ill surgical patients. This distinction is important, given the potential risks of aggressive antifungal therapy. In order to evaluate the significance of fungal infections by various sites, we retrospectively reviewed the clinical courses of patients with cultures positive for fungi (Candida species or Torulopsis glabrata) in the SICU of LAC + USC Medical Center from January 1992-December 1993. There were 129 patients who were culture positive for Candida (110 patients) or Torulopsis glabrata (19 patients). There were 187 positive cultures. Fifty-five patients (43%) had systemic fungal infections (two or more sites, or fungemia). The proportion of patients with positive cultures from any given site going on to develop systemic infections was similar (wound, 49 per cent; urine, 54 per cent; sputum, 57 per cent; drain, 68 per cent; P = 0.61, NS). The mortality for SICU patients with systemic fungal infection was significantly increased (36.3% versus 10.5%, P < 0.05) when compared with SICU patients in general. No significant increase in mortality was seen in patients with single site isolation (13.5% versus 10.5%, P = 0.52). This study suggests that although systemic fungal infection is associated with increased mortality in SICU patients, no single site of isolation is superior to others in predicting which patients are likely to develop systemic infection. Prospective studies with antifungal agents with reduced toxicity are justified in patients with single site isolation.
Injury to the common iliac artery is very uncommon in blunt trauma. We report two cases of intimal tear that led to thrombotic occlusion of the left common iliac artery in victims of motor vehicle collisions.
A retrospective study was performed in order to evaluate early morbidity and mortality associated with non-therapeutic operations for penetrating trauma. Over a 3-year period, 1,062 operations were performed on 1,015 patients for penetrating injury: abdomen 860, chest 103, neck 40, and extremities 58. A total of 230 (21.7%) of these operations were non-therapeutic. The incidence of significant complications directly related to the anesthesia or operation in this group of patients was 8.2 per cent. One patient with an additional major thoracic injury died secondary to complications related to a non-therapeutic abdominal operation (0.4%). The average hospital stay for uncomplicated non-therapeutic operations was 5.1 days, and for patients with complications 11.9 days. We conclude that non-therapeutic operations for penetrating trauma are associated with significant morbidity and mortality that must be considered when designing management schemes for penetrating injury.
Explore the source record for details and available documents.
We have investigated the role of retained bullets and other possible risk factors in the development of local septic complications after gunshot wounds (GSW) of the spine. Of 153 patients with GSW of the spine followed up for a mean of 28 months, the overall incidence of bullet wound related septic complications was 9.8%. In 81 patients the bullet was retained and the incidence of local septic complications was 7.4%. In 72 patients the bullet left the body (70) or was removed on admission (2), and the sepsis rate was 12.5% (P > 0.05). In 24 patients there was an associated colonic injury and the incidence of sepsis was 8.4% compared with 5% in the group of patients with intra-abdominal injuries but no colonic trauma (P > 0.05). The incidence of septic complications in lumbar spine injuries was significantly higher than in thoracic and cervical spine injuries (P > 0.05). We believe that in GSW of the spine, retained bullets do not increase the likelihood of septic complications.