Challenges in presenting high dimensional data to aid in triage in the DARPA virtual soldier project.

One of the goals of the DARPA Virtual Soldier Project is to aid the field medic in the triage of a casualty. In Phase I, we are currently collecting 12 baseline experimental physiological variables and a cardiac gated Computed Tomography (CT) imagery for use in an prototyping a futuristic electronic medical record, the "Holomer". We are using physiological models and Kalman filtering to aid in diagnosis and predict outcomes in relation to cardiac injury. The physiological modeling introduces another few hundred variables. Reducing the complexity of the above into easy-to-read text to aid in the triage by the field medic is the challenge with multiple display solutions. A description of the possible techniques follows.

Blood transfusion and total joint replacement surgery: T helper 2 (TH2) cytokine secretion and clinical outcome.

Surgery and blood transfusions have both been reported to cause decreases in various measures of cell-mediated immunity. A study of in vitro T helper lymphocyte type 2 (Th2) cytokine secretion after major joint replacement surgery was performed because these cytokines (IL4 and IL10) generally down-regulate cellular immune function. Th1 cytokines such as IL2 tend to up-regulate cellular immunity. Forty-three patients undergoing elective joint replacement surgery had pre- and multiple post-operative levels of IL2, IL4 and IL10 secretion measured and analysed with regard to demographic and clinical outcome data. Total joint replacement alone without allogeneic transfusions led to substantial increases in peak mean IL4 (2.1 times the pre-operative level) and IL10 secretion in vitro (4.3-fold) compared with much more modest increases in IL2 (1.36-fold) (P < 0.0001 for changes from baseline for each cytokine). In 14 patients who received allogeneic transfusions, these changes were greater than those in recipients of only autologous blood for IL4 (5.0-fold; P = 0.0036 vs. no allogeneic transfusion) and IL10 (15.7-fold; P = 0.079) but not for IL2 (1.38-fold; P = 0.38). The dramatic increase in Th2 cytokine secretion and minimal change in Th1 cytokine secretion after total joint replacement, with or without allogeneic transfusions, was seen regardless of type of anaesthetic, duration of surgery or whether knee or hip replacement occurred. These changes in cytokine patterns may contribute to the decreases in cellular immune function seen after surgery. Allogeneic transfusions but not autologous transfusions appear to exacerbate this immune deviation toward a T helper 2 (Th2) type response, and thus probably contribute to down-regulation of cellular immunity in the setting of joint replacement surgery.

Prevention of deep-vein thrombosis after total hip arthroplasty. Comparison of warfarin and dalteparin.

The effectiveness and safety of warfarin were compared with those of a low-molecular-weight heparin (dalteparin) for the prevention of deep-vein thrombosis after total hip arthroplasty in a prospective, randomized, multi-institutional trial. Patients who were older than eighteen years of age and were scheduled to have an elective primary or revision total hip arthroplasty were eligible; 580 patients were randomized, 550 had the operation and received prophylaxis, and 382 had evaluable venograms. Prophylaxis was provided either with warfarin beginning the night before the operation or with dalteparin beginning two hours before the operation and was continued until venography was performed. Bleeding was assessed on the basis of intraoperative blood loss, transfusion requirements, a decrease in hematocrit, and clinically identified bleeding complications. The prevalence of deep-vein thrombosis was found to be significantly lower in the patients who had received dalteparin than in those who had received warfarin (twenty-eight [15 per cent] of 192 patients compared with forty-nine [26 per cent] of 190 patients; p = 0.006). Deep-vein thrombosis occurred in the calf veins of twenty-one patients (11 per cent) who had received dalteparin and of forty-three patients (23 per cent) who had received warfarin; this difference was significant (p = 0.003). Proximal deep-vein thrombosis occurred in ten patients (5 per cent) who had received dalteparin and in sixteen patients (8 per cent) who had received warfarin; however, with the numbers available, no significant difference could be detected (p = 0.185). We also could not detect a significant difference with regard to the intraoperative and postoperative blood loss, the decrease in hematocrit, and the prevalence of major bleeding complications between the two groups; however, the patients who had received dalteparin had a significantly higher prevalence of bleeding complications involving the operative site (p = 0.03), and a significantly greater percentage required postoperative transfusions (p = 0.001). We concluded that preoperative prophylaxis with dalteparin is significantly more effective than that with warfarin in preventing deep-vein thrombosis after total hip arthroplasty. The greater effectiveness of dalteparin must be considered, however, in light of an increased need for postoperative transfusions and an increase in the prevalence of wound-related bleeding complications.

Trauma to the lung.

Injuries to the lung parenchyma occur following both blunt and penetrating trauma and usually are associated with injury to adjacent structures. In most cases, patients with lung injury require little more than chest-tube insertion and supportive care. A thoracotomy is required, however, in approximately 10% of these patients, half of whom will need pulmonary repair or resection. Because serious morbidity and mortality can follow lung injuries, surgeons must have a broad understanding of the causes, types, and pathophysiologies of lung injuries and be able to promptly diagnose and appropriately treat them.

Chevalier Jackson: the father of American bronchoesophagoscopy.

Chevalier Jackson was involved with bronchoesophagoscopy from the late 1800s until shortly before his death in 1958. A pioneer in the field, he developed numerous instruments used in peroral endoscopy and taught their safe and effective use. Most of the next generation of leaders in the field of bronchoesophagoscopy were trained in his clinics in Pittsburgh and in Philadelphia, where he held academic appointments at the six leading medical institutions of these cities. He was a keen observer, inventor, prolific writer, and humanitarian.

Accessory cardiac bronchus: CT features and clinical significance.

PURPOSE: The accessory cardiac bronchus is a rare congenital anomaly of the tracheobronchial tree that arises from the medial wall of the bronchus intermedius. This report documents the computed tomographic (CT) appearance of this anomaly. MATERIALS AND METHODS: Six patients with this anomaly were identified. All six underwent CT; three underwent correlative bronchoscopy, and one had both bronchoscopic and surgical confirmation. RESULTS: In all six cases, a distinct airway could be identified originating from the medial wall of the bronchus intermedius. Associated lung parenchymal tissue was identified in four cases, while in three cases a discrete soft-tissue mass was seen, presumably representing vascularized bronchial or vestigial parenchymal tissue. In two cases, the lumen of the airway was filled with debris. CONCLUSION: Recognition of this anomaly is important, as associated clinical complications, including recurrent episodes of both infection and hemoptysis, may be anticipated in a small percentage of patients.

Long-term complications after total knee arthroplasty with or without resurfacing of the patella.

The long-term complications related to the patella were retrospectively evaluated for 891 knees (684 patients) that had had a total arthroplasty, with or without resurfacing of the patella, with use of an unconstrained, condylar, posterior-cruciate-preserving prosthesis. The study population comprised two groups of patients who were similar in size, age, sex distribution, and diagnosis. One group (396 knees [303 patients]) had had a total knee arthroplasty with patellar resurfacing and the other group (495 knees [381 patients]) had had the same procedure without resurfacing. The average duration of follow-up was six and one-half years (range, two to fifteen years). The decision to resurface the patella was based on subjective inspection of the articular surface and on assessment of patellar tracking at the time of the operation. Resurfacing was performed if there was loss of cartilage, exposed bone, gross surface irregularities, or tracking abnormalities. Complications occurred an average of three years (range, immediately postoperatively to nine years) after the operation in the group that had had resurfacing and an average of four years (range, immediately post-operatively to ten years) postoperatively in the group that had not had resurfacing. In the group that had had resurfacing, there was loosening of the patellar component in five knees, patellar subluxation in four knees, fracture of the patella in three knees, rupture of the patellar tendon in three knees, and chronic peripatellar pain in one knee. In the group that had not had resurfacing, the complications included patellar subluxation in five knees, rupture of the patellar tendon in two knees, and chronic peripatellar pain in fifty-one knees.(ABSTRACT TRUNCATED AT 250 WORDS)

Fractures adjacent to humeral prostheses.

In a review of records and radiographs from 1974 through 1988, we identified seven patients who had a humeral fracture after either a total shoulder replacement or a shoulder hemiarthroplasty. All seven patients had complications after the fracture, and five fractures did not unite until an operation was done. All of the fractures that were treated operatively healed without sequelae. Four patients who were managed operatively had satisfactory relief of pain and one had fair relief. One patient who had a non-union refused further treatment for medical reasons. The one fracture that united without operative treatment healed with the tip of the prosthesis outside of the humeral shaft, but persistent pain led to a revision total shoulder replacement. The average time to union after the operation was approximately five months (range, four to seven months). There was a permanent decrease in the motion of the shoulder from preinjury levels in five of the six patients who had union of the fracture.

Treatment of AIDS-related bronchopleural fistula by pleurectomy.

Spontaneous pneumothorax in patients with acquired immunodeficiency syndrome (AIDS) may require prolonged therapy for treatment of a persistent bronchopleural fistula, and treatment by standard methods often fails. This pilot study was done to test the effectiveness of aggressive surgical therapy for definitive treatment of persistent bronchopleural fistula in patients with AIDS. Between March 1989 and September 1991, 44 patients with AIDS were treated for spontaneous pneumothorax with closed tube thoracostomy; 14 of these patients had development of persistent bronchopleural fistula for more than 10 days, and 2 patients had subsequent bronchopleural fistula on the opposite side. Operative therapy in 14 patients included 15 thoracotomies and one sternotomy. The bronchopleural fistula was closed directly with suture or staples in 15 procedures and resected by lobectomy in 1 patient. All 14 patients received adjuvant parietal pleurectomy. Operative mortality was 7% (1 of 14 patients). The fistula was closed in all survivors and 13 patients were discharged between 7 and 28 days postoperatively. Pathologic examination confirmed Pneumocystis carinii in 13 patients with a high incidence of diffuse involvement and subpleural necrosis, further demonstrating the need for pleurectomy. These data suggest that in selected patients bronchopleural fistulas associated with AIDS can be effectively controlled by surgical closure combined with pleurectomy.

Evaluation of the hip with pigmented villonodular synovitis. A case report.

Pigmented villonodular synovitis (PVNS) is an uncommon disorder of the synovium that rarely involves the hip joint. The natural history of an untreated case of PVNS is presented herein. A young adult with a painful hip and destructive changes on plain roentgenograms requires further diagnostic evaluation. The relative value of current imaging techniques is discussed in this report. Plain roentgenograms alone often suggest the correct diagnosis of PVNS of the hip, but traditional criteria have proven to be inaccurate. Computed tomography (CT) is helpful in demonstrating the location and degree of bone loss throughout the pelvis and assists in determining the need for bone graft or prosthetic modification in preoperative planning. Experience with magnetic resonance imaging (MRI) in this disorder is limited, but no clear advantage over CT has been demonstrated thus far. Three-dimensional reconstruction has provided no useful information not already found on plain CT or MRI. For diagnostic accuracy and effective preoperative planning, evaluation should include a complete blood count, sedimentation rate, CT scan, and MRI.

Patterns and complications of femur fractures below the hip in patients over 65 years of age.

This study is a retrospective review of 105 femur fractures below the hip in 99 patients over 65 years of age treated between 1970 and 1986. Problems in medical management and a high complication rate prompted this study, which focused on the fracture patterns and complications associated with these injuries. There were 25 subtrochanteric, 47 shaft, and 33 supracondylar fractures. These were isolated injuries in 89 of the patients. The overall complication rate was 45%; the orthopaedic complication rate was 15%. The mortality rate was 10% within 60 days of injury. Thirty-nine patients (39%) returned to their preinjury functional status or were able to walk with ambulatory assistive devices. Changes in mental status before fracture were associated with an increased rate of complications. Age, sex, preinjury functional status, number of preexisting medical problems, timing of surgery, type of anesthesia, and operative versus nonoperative treatment were not significantly different between survivor and nonsurvivor groups. The development of a new, postinjury medical problem in the acute treatment period was the most significant factor leading to a poor result and death. Successful management of this fracture requires aggressive medical management in the elderly.

Postoperative proximal migration in total shoulder arthroplasty. Incidence and significance.

A retrospective review of 131 Neer total shoulder arthroplasties in 111 patients performed between 1974 and 1986 was undertaken to identify factors associated with proximal humeral migration. The influence of proximal migration on results was evaluated to clarify the indications for prosthetic constraint. The average follow-up period was 55 months (range: 24-124 mo). The results showed proximal migration in 22% of patients (29 shoulders). The migration was progressive in all cases, without corresponding increases in pain. Major rotator cuff tears were present in 21% of patients with a normal glenohumeral relationship and in 24% of the patients with proximal migration. Limited elevation was noted in patients with proximal migration, but all patients had improved range of motion and decreased postoperative pain. The cause of postoperative proximal migration is believed to be secondary to a combination of factors and not rotator cuff disruption alone. These data do not support the routine use of a constrained prosthesis for irreparable rotator cuff tears.

Total shoulder arthroplasty versus hemiarthroplasty. Indications for glenoid resurfacing.

The results of total shoulder arthroplasty and hemiarthroplasty in a similar patient population were compared in an effort to define more clearly the indications for resurfacing the glenoid. The results of 64 Neer hemiarthroplasties in 59 patients were compared with 146 Neer total shoulder arthroplasties in 134 patients in a retrospective review of the period between 1974 and 1986. The average follow-up period was 44 months (range, 24-124 months). Hemiarthroplasty and total shoulder arthroplasty produced similar results in terms of functional improvement. Pain relief, range of motion, and patient satisfaction were better with total shoulder arthroplasty than hemiarthroplasty in the rheumatoid population. Progressive glenoid loosening was found in 12% of total should arthroplasties but no correlation with pain relief or range of motion was noted. Total shoulder arthroplasty is recommended for patients with inflammatory arthropathies, and hemiarthroplasty is recommended for patients with osteoarthritis, avascular necrosis, and four-part fractures with preservation of glenoid congruity and absent synovitis.

Surgical treatment of the elbow in rheumatoid arthritis.

Major disability secondary to involvement of the elbow in RA is uncommon. The indications for surgery are pain and loss of motion unresponsive to medical management. With painful synovitis and decreased function, good results are obtained with synovectomy and radial head excision. Advanced joint destruction may require TEA which produces good to excellent results in 75 to 90 per cent of cases. Arthrodesis of the elbow is not a useful procedure in patients with rheumatoid arthritis and multiple joint involvement. Salvage procedures such as resection arthroplasty and distraction arthroplasty can produce fair results in most cases.

Surgical treatment of osteoarthritis of the shoulder.

Shoulder dysfunction is unusual in osteoarthritis and usually responds to conservative treatment. The primary indication for surgery is pain unresponsive to medical management. The procedure of choice for degenerative changes in the glenohumeral joint is hemiarthroplasty or total shoulder replacement depending on the condition of the glenoid. Shoulder fusion is rarely necessary for osteoarthritis and is recommended for chronic infection, flail shoulder, and failed total shoulder replacement not amenable to revision. Joint resection is reserved for infected joints with massive bone loss. The results of shoulder arthroplasty are good to excellent in 86 to 94 per cent of all patients. The results of shoulder arthrodesis are less predictable, but are usually satisfactory in approximately 75 per cent of patients with 10-year follow-up. The treatment of AC and SC joint arthritis is conservative with rest, local heat, and medication. Pain unresponsive to this regimen is an indication for resection of the joint. Good results with this procedure directly correlate with pain relief on injection of the joint with local anesthetic.

Comparison of CT and fiberoptic bronchoscopy in the evaluation of bronchial disease.

CT was compared to fiberoptic bronchoscopy in a large series of patients to study the value of CT for visualizing bronchial disease. CT scans were available for review in 64 cases in which focal airway disease was identified with fiberoptic bronchoscopy and in 38 patients in whom the airways appeared normal at bronchoscopy. CT was positive in 59 of 64 cases in which lesions were detected endoscopically. If the results are analyzed according to the extent of involvement of individual bronchi, CT successfully identified 88 (90%) of 98 lesions. CT correctly excluded disease in 35 (92%) of 38 cases that were subsequently verified to be normal by fiberoptic bronchoscopy. In no case was the diagnosis of malignancy missed by CT. While extremely accurate in detecting focal lesions, CT was inaccurate in predicting whether a given abnormality was endobronchial, submucosal, or extrinsic (peribronchial). In three cases CT failed to detect submucosal extension into the left mainstream bronchus, which has important implications concerning the value of CT in staging bronchial malignancy. It is concluded that CT is helpful when bronchoscopy is contraindicated or refused. CT may also be used in selected cases when there is low clinical suspicion of endobronchial disease and as a complementary procedure to fiberoptic bronchoscopy for outlining the exact location of major mediastinal and hilar vessels, lymph nodes, and tumor in relation to adjacent airways.