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D A Spain

Publications and source records attributed to D A Spain.

At least 19 recordsLinked to original sources
PubMed2001

Sepsis increases NOS-2 activity and decreases non-NOS-mediated acetylcholine-induced dilation in rat aorta.

INTRODUCTION: Acetylcholine (Ach) is frequently used to assess endothelium-dependent vasodilation during sepsis. However, the effects of sepsis on constitutive nitric oxide synthase activity (NOS-1 and -3) and other non-NOS effects of Ach are unclear. METHODS: Sepsis was induced in rats by inoculation of an implanted sponge with Escherichia coli and Bacteroides fragilis (10(9) CFU each). Thoracic aortic rings (2 mm) were harvested at 24 h from septic (N = 9) and control (N = 9) rats and were suspended in physiological salt solution (PSS), PSS + l-N(6)-(1-iminoethyl)lysine (l-NIL: NOS-2 inhibitor, 10 microM), or PSS + l-N(G)-monomethylarginine (l-NMMA: NOS-1, -2, and -3 inhibitor, 60 microM). Rings were set at 1-g preload and precontracted with phenlyephrine (10(-8) M). Relaxation dose-response curves were generated with six doses of Ach (3 x 10(-8) to 10(-5) M). RESULTS: Sepsis increased the maximal relaxation to Ach under basal conditions. NOS 2 inhibition with l-NIL decreased Ach-induced relaxation in controls (66% vs 84%, P < 0.05, two-way ANOVA) and more so in septic rats (44% vs 93%, P < 0.05). Total NOS inhibition with l-NMMA decreased Ach-induced relaxation to 45% (P < 0.05) in controls and to 30% (P < 0.05) in septic animals. CONCLUSIONS: Inhibition of NOS-1, -2, and -3 failed to abolish Ach-induced relaxation, suggesting the presence of other Ach-induced vasodilator mechanisms. NOS-2 inhibition reduced Ach-induced relaxation by 20-25% in the normal thoracic aorta, but by 50% in septic animals. The remaining Ach-induced non-NOS vasodilation (after inhibition of NOS-1 + NOS-2 + NOS-3) was reduced from 45% in normals to 30% in septic animals. Vascular dysregulation in sepsis is a complex event involving increased NOS-2, decreased NOS-1 + NOS-3, and decreased Ach-induced non-NOS vasodilator mechanisms.

Acetylcholine↗
PubMed2001

A multicenter evaluation of whether gender dimorphism affects survival after trauma.

BACKGROUND: The frequency of women who have sustained severe injuries has increased over the past 30 years. The purpose of this study was to evaluate whether severely injured women have a survival advantage over men. To address this issue, we undertook a multicenter evaluation of the effects of gender dimorphism on survival in trauma patients. METHODS: Patient information was collected from the databases of three level I trauma centers. We included all consecutive patients who were admitted to these centers over a 4-year period. We evaluated the effects of age, gender, mechanism of injury, pattern of injury, Abbreviated Injury Score (AIS), and Injury Severity Score (ISS) on survival. RESULTS: A total of 20,261 patients were admitted to the three trauma centers. Women who were younger than 50 years of age (mortality rate 5%) experienced a survival advantage over men (mortality rate 7%) of equal age (odds ratio 1.27, P <0.002). This advantage was most notably found in the more severely injured (ISS >25) group (mortality rate 28% in women versus 33% in men). This difference was not attributable to mechanism of injury, severity of injury, or pattern of injury. CONCLUSIONS: Severely injured women younger than 50 years of age have a survival advantage when compared with men of equal age and injury severity. Young men have a 27% greater chance of dying than women after trauma. We conclude that gender dimorphism affects the survival of patients after trauma.

Female↗
PubMed2001

Development and implementation of a clinical pathway for spinal cord injuries.

The authors have developed a clinical pathway for the treatment of spinal cord injuries to help improve patient care. A clinical pathway for the treatment of patients with spinal cord injury was developed through a multidisciplinary approach. The control group (group 1) consisted of patients who were treated in the 2 years before the initiation of the pathway. Data from patients treated in conjunction with this pathway were collected prospectively (group 2). Thirty-six patients were treated in conjunction with the pathway compared with 22 in the control group. Group 2 had 6.8 fewer intensive care unit days, 11.5 fewer hospital days, 6 fewer ventilator days (p < 0.05), and a lower rate of complications. The use of a clinical care pathway for spinal cord injuries has resulted in improved patient care and fewer complications.

Adult↗
PubMed2001

Penetrating colon injuries requiring resection: diversion or primary anastomosis? An AAST prospective multicenter study.

BACKGROUND: The management of colon injuries that require resection is an unresolved issue because the existing practices are derived mainly from class III evidence. Because of the inability of any single trauma center to accumulate enough cases for meaningful statistical analysis, a multicenter prospective study was performed to compare primary anastomosis with diversion and identify the risk factors for colon-related abdominal complications. METHODS: This was a prospective study from 19 trauma centers and included patients with colon resection because of penetrating trauma, who survived at least 72 hours. Multivariate logistic regression analysis was used to compare outcomes in patients with primary anastomosis or diversion and identify independent risk factors for the development of abdominal complications. RESULTS: Two hundred ninety-seven patients fulfilled the criteria for inclusion and analysis. Overall, 197 patients (66.3%) were managed by primary anastomosis and 100 (33.7%) by diversion. The overall colon-related mortality was 1.3% (four deaths in the diversion group, no deaths in the primary anastomosis group, p = 0.012). Colon-related abdominal complications occurred in 24% of all patients (primary repair, 22%; diversion, 27%; p = 0.373). Multivariate analysis including all potential risk factors with p values < 0.2 identified three independent risk factors for abdominal complications: severe fecal contamination, transfusion of > or = 4 units of blood within the first 24 hours, and single-agent antibiotic prophylaxis. The type of colon management was not found to be a risk factor. Comparison of primary anastomosis with diversion using multivariate analysis adjusting for the above three identified risk factors or the risk factors previously described in the literature (shock at admission, delay > 6 hours to operating room, penetrating abdominal trauma index > 25, severe fecal contamination, and transfusion of > 6 units blood) showed no statistically significant difference in outcome. Similarly, multivariate analysis and comparison of the two methods of colon management in high-risk patients showed no difference in outcome. CONCLUSION: The surgical method of colon management after resection for penetrating trauma does not affect the incidence of abdominal complications, irrespective of associated risk factors. Severe fecal contamination, transfusion of > or = 4 units of blood within the first 24 hours, and single-agent antibiotic prophylaxis are independent risk factors for abdominal complications. In view of these findings, the reduced quality of life, and the need for a subsequent operation in colostomy patients, primary anastomosis should be considered in all such patients.

Adult↗
PubMed2001

Impact of recent trends of noninvasive trauma evaluation and nonoperative management in surgical resident education.

BACKGROUND: The use of ultrasonography and nonoperative management of solid organ injury has become standard practice in many trauma centers. Little is known about the effects of these changes on resident educational experience. METHODS: We retrospectively reviewed resident evaluation of abdominal trauma and trauma operative experience as reported to the residency review committee between 1994 and 1999. RESULTS: A total of 4,052 patients underwent one or more of three diagnostic modalities. The nontherapeutic laparotomy rate as a result of positive diagnostic peritoneal lavages decreased from 35% to 14%. Although resident operative trauma experience was stable because of increases in operative burns and nonabdominal trauma, the number of abdominal procedures declined. CONCLUSION: Noninvasive diagnostic tests have allowed more rapid trauma evaluation and fewer nontherapeutic laparotomies. As nonoperative experience grows, the opportunity for operative experience decreases. These trends may adversely affect the education of residents and suggest that novel approaches are needed to ensure adequate operative experience in trauma.

Abdominal Injuries↗
PubMed2001

Progressive decrease in constrictor reactivity of the non-absorbing intestine during chronic sepsis.

Chronic sepsis leads to an impaired intestinal microcirculation, which might reflect altered microvascular control. We hypothesized that intestinal microvascular sensitivity to norepinephrine (NE) is decreased during chronic sepsis. Chronic sepsis was induced by a polymicrobial inoculation of implanted subcutaneous sponges in rats. Septic rats were studied either 24 or 72 h after a single inoculation (1-hit) of bacteria. Other rats received a second inoculation (2-hit) of bacteria 48 h later and were studied at 24 h after the second inoculation. NE (0.01-1.0 microM) responses in the non-absorbing terminal ileal arterioles (inflow A1, proximal-p and distal-d premucosal A3) were measured by video microscopy. NE threshold sensitivity (pD(T20) = -log of 20% response dose) was analyzed. pD(T20) was significantly decreased in A1, pA3, and dA3 of 1-hit 24-h septic rats (P < 0.05), and was further decreased in all vessels of 2-hit 72-h septic rats (P < 0.05). In contrast, the pDT(T20) of all three vessels significantly returned toward normal values after 72 h in rats that had only 1 bacteria inoculation. We conclude that an initial bacterial challenge decreases vasoconstrictor reactivity of the intestinal microcirculation and that subsequent repeated bacterial challenge exacerbates this defect in vasoconstrictor control in the non-absorbing intestine.

Animals↗
PubMed2001

Successful incorporation of the Severe Head Injury Guidelines into a phased-outcome clinical pathway.

Clinical pathways have been proven to be valuable tools in improving outcomes in patients with neurological diagnoses. However, their use with trauma populations has been limited. The unpredictable nature of trauma makes it difficult to develop a day-by-day plan of care that would be applicable to all patients with the same trauma diagnosis. Nevertheless, a severe traumatic brain injury (TBI) clinical pathway was developed and implemented at a Level 1 Trauma Center with significant reductions in length of stay and number of ventilator days. With the publication of the Guidelines for the Management of Severe Head Injury, this pathway was refashioned into a severe TBI phased-outcome pathway. Rather than a day-by-day plan of care, this clinical pathway consists of four phases of care: (a) admission to the intensive care unit, (b) acute critical care, (c) mobility and weaning, and (d) pre-rehabilitation. After 12 months, the improvements accomplished by the original pathway have been maintained or exceeded.

Adult↗
PubMed2001

Does cell-saver blood administration and free hemoglobin load cause renal dysfunction?

Our aim was to evaluate the impact of cell-saver volume and free hemoglobin load on renal dysfunction. Intraoperative blood salvage was conducted in standard fashion, and in each case a sample of the blood was removed for testing. Outcome data on individual patients were collected during a 6-year period (1992-1998). The total amount of free hemoglobin each patient received was calculated. Renal dysfunction was defined as a rise in creatinine level of 1.0 mg/dL above baseline. There were a total of 125 patients who received salvaged blood. The free hemoglobin concentration ranged from 19 to 304 mg/dL (mean, 87.5 mg/dL). Patients were stratified into groups on the basis of the total free hemoglobin received, and the Kruskal-Wallis test demonstrated a difference between groups in the prevalence of renal dysfunction (P < 0.001). A total of 15 patients (12%) had significant postoperative renal dysfunction. There was an association between the amount of free hemoglobin load and subsequent renal dysfunction. This may warrant further study toward establishing policies and limits regarding maximal free hemoglobin blood.

Adult↗
PubMed2001

Thermal injury in the elderly: when is comfort care the right choice?

The factors contributing to a higher mortality rate in elderly thermal injury victims are not well delineated. The purpose of this study is to determine the impact of the initial injury, medical comorbidities, and burn size on patient outcome and to determine a level of injury in this population when comfort care is an appropriate first choice. Individual medical records of patients over 65 years of age admitted to our burn center over a 10-year interval were reviewed for patient demographics, mechanism of injury, total body surface area (TBSA) burned, medical comorbidities, use of Swan-Ganz catheters, evidence of inhalation injury, level of support, and patient outcome. The mechanisms of thermal injury were flame (68%), scald (21%) and electrical or chemical contact (11%). Twenty-six preventable bathing, cooking, and smoking-related injuries were seen (33%). The average TBSA was 25 per cent. Average length of stay varied depending on outcome. The overall mortality rate for this group was 45 per cent. Patients older than 80 years with 40 per cent or greater TBSA burned had a 100 per cent mortality rate despite aggressive treatment. Burn wound size correlated better with probability of poor outcome than age. Thermal injuries in the elderly are becoming more important with the aging of our population. Underlying medical problems--specifically chronic obstructive pulmonary disease--do play a role in increased patient morbidity and mortality. This study shows that age greater than 80 years in combination with burns greater than 40 per cent TBSA are uniformly fatal despite aggressive therapy. We believe that delaying the start of comfort-only measures in this situation only prolongs the pain and suffering for the patient, the family, and the physician.

Age Factors↗
PubMed2000

Delayed laparoscopy facilitates the management of biliary peritonitis in patients with complex liver injuries.

BACKGROUND: Nonoperative management is now regarded as the best alternative for the treatment of patients with complex blunt liver injuries. However, some patients still require surgical treatment for complications that were formerly managed with laparotomy and a combination of image-guided studies. METHODS: We reviewed the medical records of 15 patients who had complex blunt liver injuries that were managed nonoperatively and in which biliary peritonitis developed. RESULTS: Delayed laparoscopy was performed 2-9 days after admission in patients with extensive liver injuries. All 15 patients had developed local signs of peritonitis or a systemic inflammatory response. Laparoscopy was indicated to drain a large retained hemoperitoneum (eight patients), bile peritonitis (four patients), or an infected perihepatic collection (three patients). Laparoscopy was successful in all patients, and there was no need for further interventions. CONCLUSION: The data indicate that as more patients with complex liver injuries are treated nonoperatively and the criteria for nonoperative management continue to expand, more patients will need some type of interventional procedure to treat complications that historically were managed by laparotomy. At this point, laparoscopy is an excellent alternative that should become part of the armamentarium of the trauma surgeons who treat these patients.

Adolescent↗
PubMed2000

Lazaroid and pentoxifylline suppress sepsis-induced increases in renal vascular resistance via altered arachidonic acid metabolism.

Early sepsis leads to renal hypoperfusion, despite a hyperdynamic systemic circulation. It is thought that failure of local control of the renal microcirculation leads to hypoperfusion and organ dysfunction. Of the many mediators implicated in the pathogenesis of microvascular vasoconstriction, arachidonic acid metabolites are thought to be important. Vasoconstriction may be due to excess production of vasoconstrictors or loss of vasodilators. Using the isolated perfused kidney model, we describe a sepsis-induced rise in renal vascular resistance and increased production of key arachidonic acid metabolites, both vasoconstrictors and vasodilators, suggesting excessive production of vasoconstrictors as a cause for microcirculatory hypoperfusion. There is evidence of increased enzymatic production of arachidonic acid metabolites as well as nonenzymatic, free radical, catalyzed conversion of arachidonic acid. Pentoxifylline (a phosphodiesterase inhibitor) and U74389G (an antioxidant) both have a protective effect on the renal microcirculation during sepsis. Both drugs appear to alter the renal microvascular response to sepsis by altering renal arachidonic acid metabolism. This study demonstrates that sepsis leads to increased renal vascular resistance. This response is in part mediated by metabolites produced by metabolism of arachidonic acid within the kidney. The ability of drugs to modulate arachidonic acid metabolism and so alter the renal response to sepsis suggests a possible role for these agents in protecting the renal microcirculation during sepsis.

Animals↗
PubMed2000

Routine intragastric feeding following traumatic brain injury is safe and well tolerated.

BACKGROUND: Delayed gastric emptying following traumatic brain injury (TBI) has led some to advocate jejunal feeding. Our purpose was to review our experience with percutaneous endoscopic gastrostomy (PEG) and intragastric feeding in TBI patients to assess safety and effectiveness. METHODS: All patients on a TBI clinical pathway at our institution were targeted for early PEG. After PEG, standard enteral nutrition was initiated. Abdominal examination and gastric residual volumes were used to assess tolerance. RESULTS: There were 118 patients with moderate to severe TBI. The average age was 36 years. Mean Injury Severity Score (ISS) was 25. Enteral access was obtained and intragastric feeding was initiated on day 3. 6. Intragastric feeding was tolerated without complication in 111 of 114 (97%) patients. Five patients aspirated, but had no evidence of intolerance prior to the event. CONCLUSIONS: PEG provided reliable enteral access in moderate to severe TBI patients. Intragastric feeding was well tolerated with a low complication rate (4%).

Adolescent↗
PubMed2000

Sustained infection induces 2 distinct microvascular mechanisms in the splanchnic circulation.

BACKGROUND: Altered intestinal blood flow during systemic inflammation leads to organ dysfunction. Mucosal ischemia occurs during sepsis despite an increase in portal blood flow. We hypothesized that separate mechanisms are active in the large resistance and small mucosal microvessels to account for this dichotomy. METHODS: Chronic infection was induced in rats by bacterial inoculation (Escherichia coli and Bacteroides fragilis) of an implanted subcutaneous sponge. Separate groups were studied at 24 and 72 hours after a single inoculation of bacterium or 24 hours after a second inoculation (ie, 72 hours of sepsis). Time-matched controls were used for each group. Intravital microscopy of the terminal ileum was used to assess endothelial-dependent vasodilation to acetylcholine (10(-9) to 10(-5) mol/L) in resistance (A(1)) and premucosal (A(3)) arterioles. Threshold sensitivity (-log of 20% response dose) was calculated from dose response curves for each animal. RESULTS: Vasodilator sensitivity to acetylcholine in A(1) arterioles was significantly decreased at 24 hours, and these changes persisted up to 72 hours after a single bacterial inoculation. There was no change in the dilator sensitivity of A(3) arterioles after a single inoculation. When there was a challenge with a second bacterial inoculation, there was a reversal of the A(1) dilator response and an increase in A(3) sensitivity. CONCLUSIONS: An initial septic event results in a decrease in dilator reactivity in the resistance A1 arterioles that persists for at least 72 hours. A sustained septic challenge results in increased dilator reactivity in both A(1) and A(3) vessels. This enhanced sensitivity during sepsis suggests that more than 1 therapeutic approach to preservation of intestinal blood flow will be necessary.

Acetylcholine↗
PubMed2000

Evolution in the management of hepatic trauma: a 25-year perspective.

OBJECTIVE: To define the changes in demographics of liver injury during the past 25 years and to document the impact of treatment changes on death rates. SUMMARY BACKGROUND DATA: No study has presented a long-term review of a large series of hepatic injuries, documenting the effect of treatment changes on outcome. A 25-year review from a concurrently collected database of liver injuries documented changes in treatment and outcome. METHODS: A database of hepatic injuries from 1975 to 1999 was studied for changes in demographics, treatment patterns, and outcome. Factors potentially responsible for outcome differences were examined. RESULTS: A total of 1,842 liver injuries were treated. Blunt injuries have dramatically increased; the proportion of major injuries is approximately 16% annually. Nonsurgical therapy is now used in more than 80% of blunt injuries. The death rates from both blunt and penetrating trauma have improved significantly through each successive decade of the study. The improved death rates are due to decreased death from hemorrhage. Factors responsible include fewer major venous injuries requiring surgery, improved outcome with vein injuries, better results with packing, and effective arterial hemorrhage control with arteriographic embolization. CONCLUSIONS: The treatment and outcome of liver injuries have changed dramatically in 25 years. Multiple modes of therapy are available for hemorrhage control, which has improved outcome.

Cause of Death↗
PubMed2000

Should trauma surgeons do general surgery?

OBJECTIVE: Many trauma centers have separated emergency and general surgery from trauma care. However, decreased trauma volume and more frequent nonoperative management may limit operative experience and the economic viability of the trauma service. Trauma surgeons at our Level I trauma center have long provided all emergency surgical care and elective surgery. We sought to determine the impact of this policy. METHODS: We reviewed all admissions to the trauma service from June of 1992 to July of 1998 and cross-referenced this with our trauma registry. The number of major and minor procedures performed was also determined, and we reviewed all operative procedures by the trauma service for June of 1996 to October of 1998. RESULTS: Total admissions by the trauma service averaged 3,003 patients/year (range, 2,798-3,198 patients). Nontrauma patients accounted for 34% of all trauma service admissions (range, 26-40%). During this time period, there was no change in volume of operative or intensive care unit procedures, whereas minor procedures recently decreased from a peak of 141/month to 50/month. This was largely due to decreased use of diagnostic peritoneal lavage (surgeon reimbursable) and an increased use of computed tomographic scan and ultrasound (not presently reimbursed) to evaluate blunt abdominal trauma. During the past 2 years, nontrauma cases accounted for 33% of all operative procedures by the trauma service. CONCLUSIONS: Maintenance of emergency and general surgical care by the trauma service has allowed us to buffer impact of variations in trauma volume and to maintain operative skills in an era of increased nonoperative management of many injuries.

Abdominal Injuries↗
PubMed2000

Practice Management Guidelines for Prophylactic Antibiotic Use in Tube Thoracostomy for Traumatic Hemopneumothorax: the EAST Practice Management Guidelines Work Group. Eastern Association for Trauma.

Multiple factors contribute to the development of posttraumatic empyema. These factors include the conditions under which the tube is inserted (emergent or urgent), the mechanism of injury, retained hemothorax, and ventilator care. The incidence of empyema in placebo groups ranges between 0 and 18%. The administration of antibiotics for longer than 24 hours did not seem to significantly reduce this risk compared with a shorter duration, although the numbers in each series were small. Most reports found a significant reduction in pneumonitis when patients received prolonged prophylactic antibiotics. This use of antibiotics might possibly be better described as presumptive therapy rather than prophylactic.

Antibiotic Prophylaxis↗