Biomedical subjects

Timothy C Fabian

Publications and source records attributed to Timothy C Fabian.

46 records · Page 3Linked to original sources

PubMed2002

Improving outcomes following penetrating colon wounds: application of a clinical pathway.

INTRODUCTION: During World War II, failure to treat penetrating colon injuries with diversion could result in court martial. Based on this wartime experience, colostomy for civilian colon wounds became the standard of care for the next 4 decades. Previous work from our institution demonstrated that primary repair was the optimal management for nondestructive colon wounds. Optimal management of destructive wounds requiring resection remains controversial. To address this issue, we performed a study that demonstrated risk factors (pre or intraoperative transfusion requirement of more than 6 units of packed red blood cells, significant comorbid diseases) that were associated with a suture line failure rate of 14%, and of whom 33% died. Based on these outcomes, a clinical pathway for management of destructive colon wounds was developed. The results of the implementation of this pathway are the focus of this report. METHODS: Patients with penetrating colon injury were identified from the registry of a level I trauma center over a 5-year period. Records were reviewed for demographics, injury characteristics, and outcome. Patients with nondestructive injuries underwent primary repair. Patients with destructive wounds but no comorbidities or large transfusion requirement underwent resection and anastomosis, while patients with destructive wounds and significant medical illness or transfusion requirements of more than 6 units/blood received end colostomy. The current patients (CP) were compared to the previous study (PS) to determine the impact of the clinical pathway. Outcomes examined included colon related mortality and morbidity (suture line leak and abscess). RESULTS: Over a 5.5-year period, 231 patients had penetrating colon wounds. 209 survived more 24 hours and comprise the study population. Primary repair was performed on 153 (73%) patients, and 56 patients had destructive injuries (27%). Of these, 40 (71%) had resection and anastomosis and 16 (29%) had diversion. More destructive injuries were managed in the CP group (27% vs. 19%). Abscess rate was lower in the CP group (27% vs. 37%), as was suture line leak rate (7% vs. 14%). Colon related mortality in the CP group was 5% as compared with 12% in the PS group. CONCLUSIONS: The clinical pathway for destructive colon wound management has improved outcomes as measured by anastomotic leak rates and colon related mortality. The data demonstrated the need for colostomy in the face of shock and comorbidities. Institution of this pathway results in colostomy for only 7% of all colon wounds.

Abdominal Abscess↗

PubMed2002

Associated injuries in blunt solid organ trauma: implications for missed injury in nonoperative management.

BACKGROUND: During the past decade, nonoperative management (NOM) of hemodynamically stable blunt trauma patients with liver (L) or spleen (S) injury has become the standard of care. This trend has led to concerns over missed associated intra-abdominal injuries with concomitant morbidity. To better understand the incidence and risk of missed injury, patterns of associated intra-abdominal injury were examined in all patients with blunt liver and spleen injuries, and missed injuries were reviewed in patients undergoing NOM. METHODS: Patients were identified from the registry of a Level I trauma center over a 3-year period. Records were reviewed for demographics, injury characteristics, and associated injuries. Indications for primary operation were hemodynamic instability or significant associated intra-abdominal injury. Missed injury was defined as unsuspected intra-abdominal injury requiring laparotomy in patients otherwise undergoing NOM for liver or spleen injury. RESULTS: Eight hundred three patients (338 in the L group, 345 in the S group, and 120 in the L + S group) were treated between December 1995 and December 1998. Rates of planned NOM were 89% (L group), 78% (S group), and 75% (L + S group). On examination of all patients with blunt liver or spleen injuries, the incidence of associated intra-abdominal injury was higher in the L group at 5% as compared with 1.7% in the S group (p = 0.02). The associated intra-abdominal injury rate in the L + S group was similar to the L group at 4.2%. Although in the L and S groups, rates of diaphragm (0.5% vs. 1%, p = 0.45) and intra-abdominal bladder injury (0.3% vs. 0.3%, p = 0.99) were similar, bowel injury was more common in the L group (11% vs. 0%, p = 0.0004), as was pancreatic injury (7% vs. 0%, p = 0.007). In NOM patients, missed injury occurred in seven (2.3%) L patients versus zero S patients (p = 0.012). No L + S patient had unexpected injuries. Missed injuries included two small bowel, three diaphragm, one pancreas, and one mesenteric tear. CONCLUSION: Damage to the pancreas and bowel is significantly associated with liver as opposed to spleen injuries. Actual missed intra-abdominal injury with NOM mirrors this pattern, occurring more often with liver than with spleen injuries. However, the overall incidence of missed injury is quite low, and should not influence decisions concerning eligibility for NOM. We speculate that the greater amount and/or different vector of energy transfer needed to injure the liver versus the spleen accounts for the greater rate of associated injuries to the pancreas/small bowel.

Abdominal Injuries↗

PubMed2002

Blunt aortic injury with concomitant intra-abdominal solid organ injury: treatment priorities revisited.

BACKGROUND: Patients with blunt aortic injury (BAI) often have concomitant liver or spleen (L/S) injuries. With increasing use of cardiopulmonary bypass with heparinization in repair of BAI, many advocate operative management of the L/S injury before aortic repair to eliminate risk of hemorrhage. We evaluated the safety of nonoperative management (NOM) of blunt L/S injuries in patients undergoing acute BAI repair with bypass. METHODS: All patients admitted over a 6-year period with BAI were identified from the registry of our Level I trauma center. Patients with isolated L/S injuries without BAI admitted over the same period served as controls. Groups were compared with regard to demographics, injury characteristics, hospital course, and mortality. RESULTS: Eighty-four patients were diagnosed with BAI from 1994 to 2000; 28 (33%) also had blunt abdominal trauma. Three patients with severe brain injury did not undergo BAI repair, and five required laparotomy before BAI repair for other intra-abdominal injuries (two for hemodynamic instability with splenic injury, and three for concomitant bowel injury). Therefore, 20 of 28 (71.4%) BAI patients with grade I or II L/S injury (Aorta L/S group) underwent planned NOM. All BAIs were repaired using partial bypass with full heparinization. These 20 patients are compared with 894 patients with grade I or II L/S injuries with no BAI (L/S group) over the same time period. There was no difference in the nonoperative failure rate of the Aorta L/S group versus the L/S group (0% vs. 1.7%). Both groups had similar complication rates. The Aorta L/S group was also compared with 56 BAIs without solid organ injury (Aorta group). Although the Aorta L/S group was more severely injured than the Aorta group (Injury Severity Score of 35.3 vs. 26.8, < 0.0001), transfusion rates (5.7 U of packed red blood cells vs. 8.0 U of packed red blood cells, p = NS), hospital days (17.9 vs. 19.1, p = NS) and mortality (10% vs. 9%, p = NS) were similar. CONCLUSION: NOM of patients with grade I or II L/S injury who undergo systemic anticoagulation with heparin for repair of BAI is safe and associated with transfusion rates similar to BAI alone. Patients with low-grade liver or spleen injuries do not require laparotomy before BAI repair using partial bypass.

Abdominal Injuries↗

PubMed2002

Does gender difference influence outcome?

BACKGROUND: Recent laboratory studies have demonstrated that immune responses differ between male and female rodents, and some clinical studies have suggested gender differences regarding incidence and mortality from sepsis. The differences appear because of both deleterious testosterone and beneficial estrogen effects; clinical trials of testosterone blockage and/or estrogen administration for male subjects have been suggested. We evaluated the effect of gender on various outcomes in trauma patients. METHODS: Trauma patients over a 52-month period were identified from the trauma registry. Early deaths were excluded. Outcomes included mortality, pneumonia (> or = 10 colony-forming units/mL in bronchoalveolar lavage effluent), acute respiratory distress syndrome, bacteremia, ventilator days, and intensive care unit and hospital length of stay. Patients were stratified by injury mechanism, gender, age (assuming women < or = 40 were premenopausal and those > 50 were postmenopausal), and injury severity. RESULTS: There were 18,133 patients identified, and 544 were excluded because of early death. There were 12,756 (73%) men and 4,833 (27%) women. There were no outcome differences after penetrating injury with respect to gender and age group. There was a survival advantage for women < or = 40 in the Injury Severity Score 16 to 24 group, but these patients had statistically less severe injury. Overall, men tended to have more infectious complications, but women had lower survival in the face of infection. Logistic regression did not identify gender as an independent predictor of mortality. CONCLUSION: Although there was a survival advantage for women in subgroup analysis, there was no overall difference in mortality. Women with pneumonia, however, had a higher mortality than men. Further understanding of potential mechanisms is necessary before hormonal manipulation studies.

Adult↗

PubMed2002

Resuscitation from severe hemorrhagic shock after traumatic brain injury using saline, shed blood, or a blood substitute.

The original purpose of this study was to compare initial resuscitation of hemorrhagic hypotension after traumatic brain injury (TBI) with saline and shed blood. Based on those results, the protocol was modified and saline was compared to a blood substitute, diaspirin cross-linked hemoglobin (DCLHb). Two series of experiments were performed in anesthetized and mechanically ventilated (FiO2 = 0.4) pigs (35-45 kg). In Series 1, fluid percussion TBI (6-8 ATM) was followed by a 30% hemorrhage. At 120 min post-TBI, initial resuscitation consisted of either shed blood (n = 7) or a bolus of 3x shed blood volume as saline (n = 13). Saline supplements were then administered to all pigs to maintain a systolic arterial blood pressure (SAP) of >100 mmHg and a heart rate (HR) of <110 beats/min. In Series 2, TBI (4-5 ATM) was followed by a 35% hemorrhage. At 60 min post-TBI, initial resuscitation consisted of either 500 mL of DCLHb (n = 6) or 500 mL of saline (n = 5). This was followed by saline supplements to all pigs to maintain a SAP of >100 mmHg and a HR of <110 beats/min. In Series 1, most systemic markers of resuscitation (e.g., SAP, HR, cardiac output, filling pressures, lactate, etc.) were normalized, but there were 0/7 vs. 5/13 deaths within 5 h (P = 0.058) with blood vs. saline. At constant arterial O2 saturation (SaO2), mixed venous O2 saturation (SvO2), cerebral perfusion pressure (CPP), and cerebral venous O2 saturation (ScvO2) were all higher, intracranial pressure (ICP) was lower, and CO2 reactivity was preserved with blood vs. saline (all P < 0.05). In Series 2, SAP, ICP, CPP, and lactate were higher with DCLHb vs. saline (all P< 0.05). Cardiac output was lower even though filling pressure was markedly elevated with DCLHb vs. saline (both P< 0.05). Neither SvO2 nor cerebrovascular CO2 reactivity were improved, and ScvO2 was lower with DCLHb vs. saline (P < 0.05). All survived at least 72 h with neuropathologic changes that included sub-arachnoid hemorrhage, midline cerebellar necrosis, and diffuse axonal injury. These changes were similar with DCLHb vs. saline. Thus, whole blood was more effective than saline for resuscitation of TBI, whereas DCLHb was no more, and according to many variables, less effective than saline resuscitation. These experimental results are comparable to those in a recent multicenter trial using DCLHb for the treatment of severe traumatic shock. Further investigations in similar experimental models might provide some plausible explanations why DCLHb unexpectedly increased mortality in patients.

Animals↗

PubMed2002

Prospective screening for blunt cerebrovascular injuries: analysis of diagnostic modalities and outcomes.

OBJECTIVE: To prospectively examine outcomes associated with an aggressive screening protocol for blunt cerebrovascular injury (BCVI), and to compare the accuracy of computed tomographic angiography (CTA) and magnetic resonance angiography (MRA) versus conventional angiography with respect to BCVI diagnosis. SUMMARY BACKGROUND DATA: In the past 5 years, BCVI (carotid and vertebral arteries) has been recognized with increasing frequency. Initial studies described blunt carotid injuries and their associated morbidity, while more recent reports have established the devastating potential of blunt vertebral injuries. It has been suggested that early diagnosis and anticoagulation will improve outcomes and that less-invasive diagnostic techniques than conventional angiography are desirable for screening. However, there are neither established screening criteria nor studies comparing optimal diagnostic modalities. METHODS: The screened population included all patients with cervical spine fractures, LeFort II or III facial fractures, Horner's syndrome, skull base fractures involving the foramen lacerum, neck soft tissue injury, or neurological abnormalities unexplained by intracranial injuries. Patients underwent screening with four-vessel cerebral angiography. During the first half of the study, patients also underwent helical CTA. Selected patients during this same period underwent MRA. At the time of diagnosis, anticoagulant or antiplatelet therapy was instituted unless clinically contraindicated. Results of this screening protocol were compared to a previously published cohort with cerebrovascular injuries (1995-1999) from the authors' institution. RESULTS: Two hundred sixteen patients were screened over a 2-year period (3.5% of all blunt trauma admissions). Angiography identified 24 patients with carotid artery injuries (CAI) and 43 patients with vertebral artery injuries (VAI) for an overall screening yield of 29%. While the incidence of CAI remained similar between the current study and the previous study group, the incidence of VAI diagnosis increased. Stroke rates in those with CAI were also similar between the two periods. The stroke rate in VAI, however, was markedly lower at 0% as compared to 14% in the previous group. Comparison of CTA and MRA with cerebral angiography in 143 patients demonstrated sensitivities of 47% and 50%, respectively, for CAI; sensitivities were 53% (CTA) and 47% (MRA) for VAI. CONCLUSIONS: Aggressive screening of patients with blunt head and neck trauma identified an incidence of BCVI in 1.03% of blunt admissions. Early identification, which led to early treatment, significantly reduced stroke rates in patients with VAI, but provided no outcome improvement with CAI. More encompassing screening may be required to improve outcomes for patients with CAI. However, less-invasive diagnostic techniques (CTA and MRA) are inadequate for screening. Technological advances are necessary before abandonment of conventional angiography, which remains the standard for diagnosis.

Adult↗

PubMed2002

Aerosolized ceftazidime for prevention of ventilator-associated pneumonia and drug effects on the proinflammatory response in critically ill trauma patients.

STUDY OBJECTIVES: To evaluate the safety and efficacy of aerosolized ceftazidime for prevention of ventilator-associated pneumonia (VAP) and to evaluate the effects of the drug on the proinflammatory response. DESIGN: Prospective, randomized, double-blind, placebo-controlled clinical trial. SETTING: University teaching hospital. PATIENTS: Forty critically ill trauma patients at high risk for VAP Intervention. Within 48 hours of admission to the intensive care unit (ICU), patients were randomly assigned to receive aerosolized ceftazidime 250 mg every 12 hours or placebo (normal saline) for up to 7 days. Bronchoalveolar concentrations of tumor necrosis factor-alpha (TNF-alpha), interleukin (IL)-1beta, IL-6, and IL-8 were determined at baseline and the end of therapy (days 4-7). MEASUREMENTS AND MAIN RESULTS: The frequency of VAP in patients receiving aerosolized ceftazidime was 73% lower than that in patients receiving placebo at ICU day 14 (15% vs 55%, p = 0.021), and 54% lower for the entire ICU stay (30% vs 65%, p = 0.022). No clinically significant changes in bacterial culture and sensitivity patterns were observed. No adverse events from aerosolized ceftazidime were reported. Pulmonary TNF-alpha, IL-beta, and IL-8 concentrations were attenuated in the ceftazidime group compared with those in the placebo group (p < 0.001, p = 0.02, and p = 0.003). The frequency of VAP was related directly to changes in TNF-alpha and IL-beta (p < 0.001, p = 0.02). CONCLUSIONS: Aerosolized ceftazidime decreased the frequency of VAP in critically ill trauma patients, without adversely affecting ICU flora. Aerosolized ceftazidime also may attenuate the proinflammatory response in the lung.

Adult↗

PubMed2002

Lactobacillus species as a cause of ventilator-associated pneumonia in a critically ill trauma patient.

Lactobacillus species are ubiquitous inhabitants of the human gastrointestinal and genitourinary tracts and rarely cause infections. Pneumonia caused by Lactobacillus has been reported only in immunocompromised patients and in one patient with structural lung disease. A 39-year-old, immunocompetent, critically ill woman developed ventilator-associated pneumonia, which was found to be caused by Lactobacillus. To our knowledge, this is the first such report. The infection was treated successfully with 14 days of intravenous vancomycin. Based on this case, Lactobacillus should be considered a possible cause of ventilator-associated pneumonia in immunocompetent, critically ill patients.

Accidents, Traffic↗

PubMed2002

Acute respiratory distress syndrome in blunt trauma: identification of independent risk factors.

Acute respiratory distress syndrome (ARDS) is a major contributor to morbidity and mortality in trauma patients. Although many injuries and conditions are believed to be associated with ARDS independent risk factors in trauma patients and their relative importance in development of the syndrome are undefined. The aim of this project is to identify independent risk factors for the development of ARDS in blunt trauma patients and to examine the contributions of each factor to ARDS development. Patients with ARDS were identified from the registry of a Level I trauma center over a 4.5-year period. Records were reviewed for demographics, injury characteristics, transfusion requirements, and hospital course. Variables examined included age >65 years, Injury Severity Score (ISS) >25, hypotension on admission (systolic blood pressure <90), significant metabolic acidosis (base deficit <-5.0), severe brain injury as shown by a Glasgow Coma Scale score (GCS) <8 on admission, 24-hour transfusion requirement >10 units packed red blood cells, pulmonary contusion (PC), femur fracture, and major infection (pneumonia, empyema, or intra-abdominal abscess). Both univariate and stepwise logistic regression were used to identify independent risk factors, and receiver operating characteristic curve (ROC) analysis was used to determine the relative contribution of each risk factor. A total of 4397 patients having sustained blunt trauma were admitted to the intensive care unit and survived >24 hours between October 1995 and May 2000. Of these patients 200 (4.5%) developed ARDS. All studied variables were significantly associated with ARDS in univariate analyses. Stepwise logistic regression, however, demonstrated age >65 years, ISS >25, hypotension on admission, 24-hour transfusion requirement >10 units, and pulmonary contusion as independent risk factors, whereas admission metabolic acidosis, femur fracture, infection, and severe brain injury were not. Using a model based on the logistic regression equation derived yields better than 80 per cent discrimination in ARDS patients. The risk factors providing the greatest contribution to ARDS development were ISS >25 (ROC area 0.72) and PC (ROC area 0.68) followed by large transfusion requirement (ROC area 0.56), admission hypotension (ROC area 0.57), and age >65 (ROC area 0.54). Independent risk factors for ARDS in blunt trauma include ISS >25, PC, age >65 years, hypotension on admission, and 24-hour transfusion requirement >10 units but not admission metabolic acidosis, femur fracture, infection, or severe brain injury. Assessment of these variables allows accurate estimate of risk in the majority of cases, and the most potent contributors to the predictive value of the model are ISS >25 and PC. Improvement in understanding of which patients are actually at risk may allow for advances in treatment as well as prevention in the future.

Acute Disease↗

PubMed2002

Infection in penetrating abdominal trauma: risk factors and preventive antibiotics.

Infection remains the greatest risk for victims of penetrating abdominal injury with major infections occurring in 10 to 15 per cent. Attributable mortality is approximately 30 per cent of those who develop major abdominal infections. In addition to this morbidity infection adds approximately $43,000.00 of hospital charges per infected patients. This article addresses two significant areas: risk factors and antibiotic utilization. The most important risk factor is the presence of hollow viscus injury; colonic wounding carries the highest incidence of infection relative to intra-abdominal organs injured. Pancreatic and liver injuries significantly increase infection risk when combined with hollow viscus wounds. The degree of injury as measured by the volume of hemorrhage and the presence of shock as well as the anatomic degree of injury likewise correlates with the incidence of septic morbidity. Antibiotic utilization is addressed by the three issues of antibiotic agents of choice, duration of administration, and optimal dosing. Regimens of choice should include anaerobic coverage. Twenty-four hours of antibiotic administration is satisfactory with currently available agents. Evidence-based medicine analyses from the Eastern Association for the Surgery of Trauma have addressed those two issues. There are few data on optimal dosing. Increased volumes of distribution and rates of excretion have been demonstrated in trauma patients. This would suggest that higher-than-normal doses should be used. Laboratory studies would support such an approach. However, significant clinical research is desirable to address issues of concentration-dependent bacterial killing and time-dependent killing. Those pharmacodynamic considerations are variable among antibiotic classes.

Abdominal Injuries↗