Clyde E. McAuley

A prehospital glasgow coma scale score < or = 14 accurately predicts the need for full trauma team activation and patient hospitalization after motor vehicle collisions.

BACKGROUND Trauma team activation protocols should ideally minimize the undertriage of seriously injured patients and eliminate unnecessary activations for those patients that do not require hospitalization. This study examined which physiologic parameter(s) most reliably predicted the need for hospitalization after motor vehicle collisions (MVCs). METHODS A prehospital triage tool using standard physiologic parameters was developed and prospectively analyzed for reliability in predicting subsequent patient admission at a Level II trauma center after MVCs. Data were collected on 4,014 consecutive patients, 2,880 (72%) of whom had all of the physiologic parameters reported and recorded. Patients who arrived in extremis, who were dead on arrival, or who died shortly after arrival despite appropriate trauma team activation were ineligible for the study. Multivariate stepwise logistic regression analysis was used to determine which parameters were associated with hospital admission. RESULTS The Glasgow Coma Scale (GCS) score was the only prehospital physiologic parameter providing a clinically identifiable difference between those patients admitted (13 +/- 4) and those discharged to home (15 +/- 0.5) (mean + SD) (relative risk for hospitalization, 2.24; 95% confidence interval, 1.86-2.70 for GCS score < 14). CONCLUSION The prehospital GCS score is a reliable physiologic parameter for predicting hospital admission after MVC. When obvious indicators (hypoxemia, multiple long bone fractures, focal neurologic deficits) for trauma team activation are lacking, the prehospital GCS score may be used to reduce overtriage and undertriage rates.

Seven-year follow-up of expanded polytetrafluoroethylene (PTFE) femoropopliteal bypass grafts

Expanded polytetrafluoroethylene (PTFE) grafts have proven to be an acceptable short-term alternative for femoropopliteal reconstruction in those patients without suitable autologous saphenous vein. One hundred and twenty-seven femoropopliteal arterial bypass operations utilizing PTFE grafts were performed in 105 patients. Seven-year follow-up is now available for 20 grafts, 6-year follow-up for 47 grafts, and 5-year follow-up for 62 grafts. Graft occlusion was determined by angiography, Doppler assessment, loss of previously palpable pulses, or return of symptoms. Thirty nonocclusive graft losses were due to death, infection, aneurysm, amputation, or proximal occlusive disease. Overall cumulative patency rate, according to occlusive criteria alone and calculated by the life-table method, was 74% at 6 months, 63% at 1 year, 48% at 3 years, 40% at 5 years, and 35% at 7 years. Excluding early bypass failures (less than 1 year patency), 75% of grafts were patent at 3 years, 63% at 5 years, and 55% patent 7 years following operation. Diabetes mellitus was associated with a significantly lower patency rate. Patency rates were not adversely affected by graft diameter, distal popliteal anastomotic site, number of patent runoff vessels, preoperative symptoms, or prior arterial reconstruction. In patients without suitable autologus saphenous vein, the PTFE graft has proven to be a durable and dependable long-term alternative for femoropopliteal reconstruction.

Bacterial presence in aortic thrombus at elective aneurysm resection: is it clinically significant?

Infected thrombus in an abdominal aortic aneurysm represents a potential source of subsequent aortic graft sepsis. Previous reports have documented a 10 to 15 percent incidence of positive results of culture of the contents of an abdominal aortic aneurysm and have recommended prolonged postoperative organism-specific antibiotic therapy when a positive culture is encountered. In our study, we cultured the intraluminal thrombus during elective aneurysm repair in 64 patients with abdominal aortic aneurysms and found bacterial growth in 9 (14 percent of all patients). Eight of the nine patients received no antibiotic therapy other than the routine prophylaxis regimen, and no evidence of either early or late prosthetic graft sepsis occurred (mean follow-up 25 months). We conclude that a positive result of culture may not imply clinical infection at the time of operation and that prolonged postoperative organism-specific antibiotic therapy does not appear necessary in the patient with an asymptomatic aneurysm and no overt evidence of infection of the aneurysm at the time of operation.

Late sequelae of gastric acid injury

The late sequelae of gastric acid injury follow a predictable pattern and often require operative correction. Pyloric and antral stenoses are the most commonly cited late complications of acid ingestion. Other late sequelae include intractable pain, achlorhydria, protein-losing gastroenteropathy, duodenal atonicity, radiographic abnormalities, mucosal metaplasia, and gastric carcinoma. Resection of the injured gastric segment appears to provide the most favorable long-term result. Diligent patient follow-up is required to ensure adequate restoration of gastrointestinal function and to correct late-appearing complications. The distinction between the expected sites of gastrointestinal injury in acid versus alkali ingestion has become less clear with the recent introduction of readily available concentrated liquid household alkaline products, and the incidence of late gastric sequelae of caustic injuries has increased accordingly.

Collagen stability and collagenolytic activity in the normal and aneurysmal human abdominal aorta

Two issues were addressed in this study. The first was whether a bona fide collagenase exists within the wall of the aorta. The second was whether the activity of this putative collagenase is greater in aneurysmal tissue. No collagenase could be extracted from the wall of the aorta under nondenaturing conditions. However, hydroxyproline was liberated from tissue samples allowed to autolyze at neutral pH under reaction conditions favoring the activity of collagenase. Such an activity was probably enzymic as it occurred in a time- and temperature-dependent fashion and was suppressed by chelators. In normal and stenotic tissue, activity was increased by adding aminophenylmercuric acetate, an activator of latent collagenase. Examination of the blanks revealed that the collagen of aneurysmal aorta was more soluble than normal. Furthermore, its digestion kinetics differed in a way that suggested that aneurysmal aorta possessed a labile component that was absent from normal tissue. Although the activity of the putative aortic collagenase was higher than normal in the aneurysmal tissue, our assays do not distinguish between changes in the amount or activity of the enzyme and alterations in the collagen.

Upper arm graft fistula for hemodialysis

The repeated failure of forearm hemodialysis access grafts in patients with end-stage renal failure often requires the use of an upper arm graft fistula. During a 7-year period, 20 upper arm graft fistulas were placed in 15 patients. The 5-year patency rate by life-table analysis, including graft fistula salvage by thrombectomy, is 53%. The mean survival from graft insertion until revision or thrombectomy is 36 months. Twenty of the twenty-two thrombectomies performed (91%) were successful in reestablishing graft fistula patency. Six grafts required more than one thrombectomy, and seven grafts required revision of the venous anastomosis. Only one arterial anastomosis required revision. We conclude that the upper arm graft fistula is an acceptable method of hemodialysis access in those patients without suitable forearm access sites. However, an aggressive approach to both graft fistula thrombectomy and the revision of stenotic anastomoses is necessary to maintain a satisfactory patency rate.