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Total parenteral nutrition (TPN) decreases intestinal IgA and levels of Th2 cytokines, interleukin (IL)-4, and IL-10 within the supernatants of intestinal homogenates. These cytokines are known to stimulate IgA production in vitro by cells of the gut-associated lymphoid tissue (GALT). Glutamine (GLN) supplementation of TPN normalizes GALT mass and cytokine levels. Because intestinal homogenates contain mucosa which itself is a source of cytokines, it was unclear whether cytokines change within the GALT itself. This study investigates dietary effects on IL-4 and IL-10 cytokine mRNA expression within isolated GALT lamina propria cells after lipopolysaccharide (LPS) stimulation. Prospective randomized experimental trials were used in this study. Fifty-nine mice were randomized to chow, intravenous TPN (IV-TPN), intragastric TPN (IG-TPN), complex enteral diet (CED), or 2% GLN-supplemented TPN (GLN-TPN). In experiment 1, animals were fed chow, IV-TPN, IG-TPN, or CED for 5 days and received intraperitoneal LPS (100 microg/kg BW), and then were sacrificed 1 h later. Intestine was harvested for GALT lamina propria. Total RNA was extracted from lamina propria cells and cytokine mRNA for IL-4, and IL-10 was measured by reverse transcriptase polymerase chain reaction. IgA levels of intestinal washing were also measured with ELISA. In experiment 2, mRNA for IL-4 and IL-10, and intestinal IgA levels were measured in mice fed chow, IV-TPN, or GLN-TPN as in experiment 1. Both IL-4 and IL-10 mRNA expression decreased significantly in IV-TPN mice compared to chow or CED feeding. IG-TPN resulted in IL-10 mRNA expression significantly lower than chow or CED but significantly better than IV-TPN. GLN preserved IL-4 and IL-10 mRNA levels, which correlated with intestinal IgA levels. Route and type of nutrition as well as GLN influence message for the Th2 type IgA-stimulating cytokines, IL-4 and IL-10, within the primary site of GALT IgA production, the lamina propria.

Magnesium (Mg) deficiency, commonly diagnosed as hypomagnesemia based upon low serum Mg concentrations, is a frequent electrolyte abnormality in critically ill patients. Intravenous replacement therapy is empiric and serum Mg concentrations have traditionally been used as guidelines for measuring efficacy. Recent studies have shown that the Mg content of mononuclear blood cells (MBCs) may provide a better index for Mg status than serum concentrations. The purpose of this study was to evaluate the effects of intravenous Mg replacement therapy on MBC Mg content and serum Mg concentrations in critically ill hypomagnesemic patients. Adult patients admitted to the trauma intensive-care unit (ICU) with serum Mg concentration 133 mumol/L), pregnancy, or those who were seropositive for HIV were excluded. Ten patients with moderate (> 0.4-0.6 mmol/L [> 1.0-1.5 mg/dL]) and severe ( 0.7). The doses of MgSO4 (0.5-0.75 mmol/kg) used in this study increased serum Mg concentrations, but did not result in a statistically significant change of MBC Mg content in this group of trauma ICU patients.

The efficacy of prophylactic vena caval filters (VCF) in reducing morbidity and mortality from pulmonary embolism (PE) in high-risk trauma patients has been shown, but minimal follow-up data is currently available. VCFs were prophylactically placed in 110 patients between August 1991 and June 1995. There was an early VCF complication rate of 7%. Twenty-two patients died; the remaining 88 patients formed the basis for the follow-up study. Forty-five patients were located and interviewed by phone, and 30 of these patients (34%) returned for evaluation. The mean follow-up time was 18 months (range, 4-42 months). There was no incidence of caval thrombosis on follow-up. Eleven patients had physical findings, and duplex evidence consistent with postphlebitic syndrome. An additional three patients had evidence of old deep venous thrombosis (DVT) by duplex, but no significant symptomatology. VCF are effective in preventing PE related deaths and have few major complications. The long-term morbidity associated with posttraumatic venous thrombosis is significant. This morbidity is related not to PE or VCF, but to the underlying DVT. Improved strategies against DVT are necessary.

Objective : Recently, transesophageal echocardiography (TEE) has been proposed as the standard for the diagnosis of traumatic disruption of the aorta (TDA), replacing aortography. The purpose of this study was to evaluate the accuracy and practicality of TEE in the diagnosis of TDA. Design : Prospective clinical trial. Materials and Methods : Patients with blunt trauma admitted with a suspected diagnosis of TDA were evaluated with TEE and aortography. Measurements and Main Results : Thirty-four patients were evaluated with TEE and aortography. TEE was unsuccessful in five patients (15%). Of the remaining 29 patients, TEE results were true-positive in four and true-negative in 20. TEE results were false-positive in two patients, and three injuries were missed (two were proximal to the left subclavian artery, and one was a localized aortic disruption). Sensitivity and specificity of TEE were 57% and 91%, respectively, compared with aortography, for which sensitivity was 89% and specificity was 100%. Conclusion : Although the use of TEE in the diagnosis of TDA has several advantages, it is not more accurate than aortography. TEE should not replace aortography as the standard for the diagnosis of TDA.

Debridement, fecal diversion, and rectal washout have been proposed as the primary therapy for complex perineal lacerations, but, in most series, survivors have a pelvic sepsis rate of 40-80%. In a retrospective study, six of 18 patients sustaining severe perineal lacerations died within the first few hours of injury due to exsanguination from pelvic injuries. The remaining 12 patients underwent sigmoidoscopy, diversion of the fecal stream with irrigation of the distal rectal stump, and radical initial debridement of necrotic soft tissue. Enteral access was obtained in two patients. In the patients with mandatory daily debridement and pulsatile irrigation, no pelvic sepsis occurred. In three patients without daily debridement, pelvic sepsis complicated recovery. The ability of patients to resume oral nutrition was significantly delayed, necessitating total parenteral nutrition in three patients. We conclude that sigmoidoscopy, total diversion of the fecal stream with irrigation of the distal rectal stump, enteral access for feeding, radical initial debridement of necrotic soft tissue, and mandatory daily debridement with pulsatile irrigation optimize recovery from this devastating injury.

Over the past 10 years, several clinical and experimental studies report the potential benefit of enteral nutrition as primary therapy after multiple system trauma. In this study, 98 patients sustaining blunt and penetrating trauma were randomised to receive either enteral or parenteral feeding for 15 days. There were significantly fewer infectious complications in patients randomised to receive enteral feeding with particular benefit shown in the most severely injured patients. Serum protein concentrations correlated with the clinical outcome with an increase in constitutive protein and decrease in acute phase protein concentrations occurring in the enteral group through a decrease in septic complications and possible direct hepatic 'reprioritisation'. Enteral feeding serves as a primary therapy affecting the outcome of critically ill patients.

Hypermetabolic, critically ill patients rapidly mobilize lean tissue, releasing large quantities of amino acids into the circulating amino acid pool for distribution to the liver, intestine, bone marrow, and injured or healing tissues. Within these sites, gluconeogenesis, immune cell proliferation, and fibroblast proliferation support the body’s attempts to seal and heal its injuries while maintaining defenses against bacterial challenges. Glutamine and alanine synthesis up-regulated through the metabolism of branched-chain amino acids by skeletal muscle provide specific fuels for enterocytes and rapidly proliferating immunocytes as well as sources of carbon skeletons for gluconeogenesis [1]. In addition, amino acids from the general amino acid pool are synthesized by the liver into acute-phase production to upregulate effectiveness of the reticuloendothelial system in clearing foreign material from the bloodstream [2]. While current opinion suggests that well-nourished patients can maintain a vigorous metabolic response for a week or perhaps longer, certain mechanisms of mucosal defenses may be influenced by nutrition support even in well-nourished patients.

In health, a symbiotic relationship exists between the human body and the bacteria which colonize its surfaces. Under normal circumstances, products of bacterial metabolism, such as short-chain fatty acids or vitamins, are critical for human well being. A single cell layer of mucosal epithelium with a complex underlying immunologic system and various innate nonspecific mechanisms allow absorption of nutrients while maintaining an effective barrier against the 1-1.5 kg of bacteria and other toxic factors. In times of illness, this balance is upset. Changes in gut permeability, inability to ingest nutrients, antibiotic pressure and many other factors alter the normal checks and balances between coexistence and absorption of toxic intraluminal products and sepsis. While two decades of research have focused on epithelial changes in permeability to toxins and bacteria, recent investigations of intestinal immunity and responses of bacteria to altered body defensives are modifying concepts of host defenses during critical illness. These new concepts in immunology and bacterial responses are the focus of this review.

Despite antiulcer prophylaxis 19 severely injured patients at our institution developed stress ulceration (SU) between 1989 and 1999 requiring surgery for perforation (n = 4) or bleeding (n = 15). A herald bleed (HB) 10.7 +/- 1.2 days after admission, 7.2 +/- 1.2 days before definitive operative therapy, and requiring 7.1 +/- 0.9 units of blood occurred in 93 per cent of patients operated on for bleeding. Bleeding preceded perforation in one patient. Central nervous system damage was part of the injury pattern in 68 per cent of the patients including spinal cord (42%), severe head injury (16%), or both (10%). Forty-two per cent had acalculous cholecystitis found at surgery. Eight patients had vagotomy and antrectomy (VA), and 11 patients had vagotomy and pyloroplasty (VP). VA required more time than VP (255 +/- 41 vs 158 +/- 13 minutes; P = 0.02). One patient (12.5%) rebled after VA versus two (18%) after VP; one patient in each group required reoperation. There was no difference in mortality, length of stay, or intensive care unit stay. A herald bleed preceded recurrent hemorrhage of SU by one week. Spinal cord or head injury increase the risk of SU. More than 40 per cent of patients with SU had acalculous cholecystitis found at operation. VA provides no benefit on rebleeding or reoperation over VP, so anatomical considerations and not rebleed rates should determine the surgical procedure.

The incidence of pneumonia and intra-abdominal abscess decreases when critically injured patients are fed enterally as opposed to intravenously or not at all [1, 2]. Our work has focused on mechanisms underlying these clinical findings. In attempting to determine how nutrient, hormonal, or pharmacologic manipulation improves immune dysfunction occurring in fasted or intravenously fed patients, the key question has been: Why does the route of nutrition impair respiratory tract defenses in critically ill patients? To pursue this issue one must understand the normal mechanisms of defense at mucosal surfaces. Our work has demonstrated a key link between the gastrointestinal tract and respiratory immunity with important observations that route of nutrition influences the structure and function of the gut-associated lymphoid tissue (GALT) [3]. GALT cellular changes influence the cytokine environment, IgA production, endothelial cell activation and recruitment.

Several randomized, prospective studies of critically injured trauma patients demonstrate a significant reduction in pneumonia or intra-abdominal abscess in patients receiving enteral nutrition compared with intravenous (IV) nutrition or no post-operative feeding [1–4]. Since these benefits do not occur in well-nourished patients undergoing elective gastrointestinal surgery or less severely injured trauma victims, the results suggest an immunologic or host defense defect induced by severity of injury or by chronic nutritional depletion. With the majority of nutrition-related infectious complications occurring in the respiratory tract, mechanisms protecting moist mucosal surfaces offer an unexplored area of research potential.

Background: Colon wounds are recognized to be highly associated with intra-abdominal abscess (IAA) after penetrating trauma, whereas gastric wounds are thought to contribute minimally to abscess because of the bactericidal effect of low pH. This study evaluated the impact of stomach or colon wounds, the contribution of other risk factors, and associated abdominal injuries on IAA. Methods: Patients with penetrating colon or stomach wounds during a 10-year period were reviewed and stratified by age, Injury Severity Score, transfusions, and associated abdominal injuries. Early deaths (

Objectives: By using abdominal computed tomographic scans in the evaluation of blunt splenic trauma, we previously identified the presence of vascular blush as a predictor of failure, with a failure of nonoperative management of 13% in that series. This finding led to an alteration in our management scheme, which now includes the aggressive identification and embolization of splenic artery pseudoaneurysms. Methods: The medical records of 524 consecutive patients with blunt splenic injury managed over a 4.5-year period were reviewed for the following information: age, Injury Severity Score (ISS), American Association for the Surgery of Trauma splenic injury grade (SIG), method and outcome of management. Results: Of the patients, 66% were male with a mean age of 32± 16, and mean ISS of 25 ± 13. A total of 180 patients (34%) were managed with urgent operation on admission (81% splenectomy (SIG 4.0), 19% splenorrhaphy (SIG 2.6)). The remaining 344 patients (66%) were hemodynamically stable and underwent computed tomographic scan and planned nonoperative management. Of these patients, 322 patients (94%) were successfully managed nonoperatively (61% of total splenic injuries). In 26 patients (8%), a contrast blush identified on computed tomographic scan was confirmed as a parenchymal pseudoaneurysm on arteriography. Twenty patients (SIG, 2.8) were successfully embolized. In six patients, technical failure precluded embolization; all required splenectomy (SIG, 4.0). A total of 22 patients (6%) failed nonoperative management, including the six with unsuccessful embolization attempts. Sixteen patients (SIG, 3.0) who had no evidence of pseudoaneurysm were explored for a falling hematocrit, hemodynamic instability, or a worsening follow-up computed tomography: 13 patients had splenectomy, and three patients had splenorrhaphy. Conclusions: Aggressive surveillance for and embolization of posttraumatic splenic artery pseudoaneurysms improved the rate of successful nonoperative management of blunt splenic trauma to 61%, with a nonoperative failure rate of only 6%. In comparison with our previous work, this reduction in failure of nonoperative management is a significant improvement (p < 0.03).

Introduction: Recent literature supports a conservative trend in the management of pancreatic injuries. Contrary to this trend, some recommend defining ductal integrity by pancreatography, implying that the results alter management. This study examines our recent 5-year experience with a simplified approach to all pancreatic injuries. Methods: Retrospective analysis of patients sustaining pancreatic injuries was performed. Results: One hundred thirty-four patients were identified. Overall mortality was 13%, and pancreatic-related mortality was 2%. Analyses were based on 124 pancreatic injuries among patients who survived >12 hours. Thirty-seven proximal injuries were treated with drainage alone, with a pancreatic morbidity of 11%. Eighty-seven distal pancreatic injuries occurred, 54 with indeterminate ductal status. Twenty-four had high probability for duct injury and were treated by distal resection; 30 with a low probability of ductal injury were drained. Pancreatic morbidity was not different between these groups. Conclusions: Pancreatic injuries including those with indeterminate ductal status can be successfully managed with low morbidity and mortality using this simplified management protocol.

Magnesium (Mg) deficiency, commonly diagnosed as hypomagnesemia based upon low serum Mg concentrations, is a frequent electrolyte abnormality in critically ill patients. Intravenous replacement therapy is empiric and serum Mg concentrations have traditionally been used as guidelines for measuring efficacy. Recent studies have shown that the Mg content of mononuclear blood cells (MBCs) may provide a better index for Mg status than serum concentrations. The purpose of this study was to evaluate the effects of intravenous Mg replacement therapy on MBC Mg content and serum Mg concentrations in critically ill hypomagnesemic patients. Adult patients admitted to the trauma intensive-care unit (ICU) with serum Mg concentrationor = 0.6 mmol/L (or = 1.5 mg/dL) were considered for study entry. Patients with severe renal disease (Scr133 mumol/L), pregnancy, or those who were seropositive for HIV were excluded. Ten patients with moderate (0.4-0.6 mmol/L [1.0-1.5 mg/dL]) and severe (or = 0.4 mmol/L [or = 1.0 mg/dL]) hypomagnesemia received 0.5 and 0.75 mmol/kg of intravenous MgSO4, respectively, over 24 h. MBC Mg content and serum concentrations of magnesium, phosphorus, calcium, sodium, potassium, blood urea nitrogen, creatinine, glucose, and albumin were measured at baseline (0 h), end of infusion (24 h), 36 h, and 48 h. Data were analyzed using ANOVA with repeated measures and a P value0.05 was considered significant. Serum Mg concentrations increased significantly from baseline to 48 h (0.5 +/- 0.1 to 0.8 +/- 0.2 mmol/L, P0.001). MBC Mg content did not change significantly within the study period (2.6 +/- 1.0 to 3.0 +/- 1.3 fmol/cell, P0.7). The doses of MgSO4 (0.5-0.75 mmol/kg) used in this study increased serum Mg concentrations, but did not result in a statistically significant change of MBC Mg content in this group of trauma ICU patients.

The early catabolic phase of severe injury is associated with acute growth hormone (GH), insulin-like growth factor-1 (IGF-1), and insulin-like growth factor binding protein-3 (IGFBP-3) deficiency. The metabolic half-life of circulating IGF-1 is prolonged by its binding to IGFBP-3. The role of this binding protein in nutritionally repleted multiple-injury patients has not been previously evaluated. We have measured plasma levels of these polypeptides and nitrogen (N) balance in 18 adult (15 males/3 females ; mean age, 45 years), severely injured, hypermetabolic, and highly catabolic trauma patients within 48 to 60 hours after injury, when they were receiving maintenance fluids without calories or N and during 6 days of total parenteral nutrition (TPN). Before instituting TPN, the patients were randomized to receive (group H, n = 9) or not to receive (group C, n = 9) daily recombinant human growth hormone (rhGH), 0.15 mg/kg IM. Adjuvant rhGH significantly increases plasma levels of GH, IGF-1, IGFBP-3, and insulin. In addition, it shows better improvement in N balance. The bioavailability of IGF-1 is increased, as indicated by the decrease in IGFBP-3 :IGF-1 ratio. A significant correlation between IGF-1 and IGFBP-3 levels is present in the trauma patients who received TPN and rhGH. A GH/IGF-1/IGFBP-3 axis that closely regulates the metabolic status of the patient is established in trauma.

To evaluate the efficacy of adding a volume reservoir to reduce variability in ventilator-induced fluctuation in inspired oxygen concentration (FiO2) and to reduce oxygen consumption measurement error, we evaluated two ventilators (Puritan-Bennett 7200 and Bear 2) at three inspired oxygen concentrations ranging from 35% to 60%. Continuous sampling of oxygen concentration was conducted for each ventilator. The maximum variability in oxygen concentration was recorded at each minute and oxygen consumption error sensitivity was calculated for both ventilators at three different oxygen concentrations, with and without the use of a baffled 3-L reservoir placed into the inspiratory circuit between the ventilator and test lung. The use of a baffled 3-L reservoir reduced oxygen consumption error sensitivity with the Puritan-Bennett 7200 ventilator at all three oxygen concentrations (p0.01). Similar results were found with the Bear 2 ventilator except at the highest FiO2, at which oxygen consumption error sensitivity was not altered. Use of a baffled volume reservoir can significantly reduce ventilator-dependent errors in measuring oxygen consumption via indirect calorimetry. However, when the FiO2 is widely variable, the reservoir is not helpful in reducing error at higher FiO2 concentrations.

The increased risk of septic complications accompanying severe illness and injury is compounded by the presence of malnutrition. Total parenteral nutrition (TPN) has been used extensively to prevent or rectify this problem. Although enteral nutrition is frequently more difficult to administer, a growing body of laboratory and clinical research shows a significant reduction in the incidence of secondary infection with its use. The mechanism proposed is that the enteral route helps maintain the gut barrier, decreasing passage of bacteria and other toxins. Translocation of these products has been implicated as a cause of nosocomial infection and organ failure. Therefore, when possible, the use of the enteral route of nutrition should be part of the overall approach to the care of the critically ill or injured patient.

Sepsis and the route of nutrient administration are clearly related to visceral protein levels; however, the mechanisms and amount of influence are not completely defined.Constitutive and acute-phase protein levels were measured on days 1, 4, 7, and 10 in 68 severely injured patients with abdominal trauma indexes of 15 or more randomized to enteral or parenteral feeding. Groups were matched for age, abdominal trauma index, injury severity score, and length of stay.Significantly higher levels of constitutive proteins and lower levels of acute-phase proteins were found in patients randomized to enteral feeding. Although some "hepatic protein reprioritization" appeared to be caused by nutrient route, this appeared only in the less severely injured patients. A more important factor in visceral protein levels is a reduction in septic morbidity associated with enteral feeding.Enteral feeding produces greater increase in constitutive proteins and greater decreases in acute-phase proteins after severe trauma primarily caused by reduced septic morbidity with enteral feeding.

There is a current trend toward nonsurgical therapy for small, minimally symptomatic acute subdural hematomas (ASDH), but data supporting such a scheme have been lacking. We evaluated 83 patients with minimally symptomatic ASDH (Glasgow Coma Scale scores of 11-15) and found 58 managed nonsurgically (70%) and 25 managed with craniotomy (30%). Patients managed without surgery had a lower incidence of focal neurologic deficits (12% vs. 40%; p.01), open cisterns (90% vs. 28%; p.001), and small (or = 1 cm) ASDHs (92% vs. 62%; p.001). Ninety-three percent of patients managed nonsurgically had functional recovery compared with 84% of patients with craniotomy. Age and injury Severity Score were significantly associated with patient outcome. Timing of surgery had no association with outcome. Six percent of patients managed nonsurgically developed chronic SDH requiring craniotomy. We conclude that unless the hematoma is causing clinical evidence of intracranial hypertension or significant neurologic dysfunction, there appears to be no advantage in evacuating the clot. Selected patients with ASDH and GCS scores of 11-15 can safely be managed without craniotomy.

Nutritional support is a vital part of the therapy of most hospitalized patients. Early initiation, particularly via the enteral route, has a significant effect on septic complications in a wide variety of patients. Early enteral feeding may also attenuate the hypercatabolic response that follows burn injury, although the evidence is somewhat conflicting. The mechanisms for the benefit of early nutrition have not been fully elucidated. However, preservation of gut mass, prevention of increased gut permeability to bacteria and other toxins, and maintenance of the gut-associated lymphoid tissue all probably play a role. The question "How early is early?" is important, since maintenance of early feeding requires time, patience, and dedication. It appears that starting nutrition within 24 hrs of major surgery, injury, or burn is ideal, but within 48 hours is acceptable. However, hemodynamic stability is a prerequisite to initiation of enteral feeding. Although labor intensive, the provision of early feeding, particularly via the enteral route, is a worthwhile goal for all clinicians.

To compare selected nutrition and immunologic markers and infection in trauma patients receiving a specialized enteral formula with those receiving standard enteral therapy.Prospective, randomized clinical trial.Level 1 trauma center at a county government hospital.Forty-one consecutive patients with major trauma who required enteral nutrition support. Thirty-seven patients completed the study. Four patients (two in each group) were excluded, as additional operative procedures prevented initiation of enteral feedings within 7 days of injury.Nineteen patients fed the specialized enteral formula received supplemental arginine, linolenic acid, beta-carotene, and hydrolyzed protein for up to 10 days. Eighteen control patients received standard enteral nutrition.After study entry, patients who received the specialized enteral formula had fewer infections than those receiving standard enteral nutrition (3/19 vs 10/18; p0.05). The change in nitrogen balance was significantly better (p0.05) from day 1 (-11.8 +/- 1.8 g/day) to day 5 (-5.9 +/- 2.0 g/day) for the group who received the specialized formula compared with the group who received standard enteral nutrition (-7.3 +/- 1.7 g/day to -7.4 +/- 2.8 g/day). Similarly, the change in C-reactive protein serum concentration was significantly better (p0.05) from day 1 (18.0 +/- 2.1 mg/dl) to day 5 (11.8 +/- 1.5 mg/dl) in the group who received the specialized formula compared with the group who received standard enteral nutrition (17.6 +/- 1.2 mg/dl to 14.4 +/- 1.7 mg/dl). The CD4:CD8 ratio increased more in the group who received the specialized formula, although this difference did not reach statistical significance.Trauma patients who received the specialized enteral formula demonstrated a decreased incidence of infection and increased improvements in nitrogen balance and other indexes of stress. Additional clinical trials demonstrating positive patient outcomes are necessary before these specialized enteral formulas are used as the standard of practice in critically ill patients.

Previous work documented a 40% depression of hepatic indocyanine green (ICG) clearance (ClICG) in pigs fasted to 20% weight loss, with return to normal within 12 days of food refeeding. ClICG in pigs is insensitive to changes in hepatic blood flow but very sensitive to changes in hepatic function (HF). Serial ClICG determinations were performed to quantify the effect of route of nutrient delivery on recovery of HF.Fourteen pigs were fasted to 20% weight loss (12.8 days average) with both gastrostomy and intravenous catheters placed in each animal midway through the fast. ClICG was measured before fast, after fast, and after 12 days refeeding through the enteral or parenteral route at 125 kcal/kg/day with isonitrogenous, isocaloric diets containing 9% fat. Urine and stool were analyzed for total nitrogen.No significant differences appeared between groups in nitrogen output during fasting (4.5 +/- 1.2 gm/kg enteral, 4.6 +/- 1.2 gm/kg parenteral), in nitrogen intake (800 +/- 19 mg/kg/day enteral, 810 +/- 10 mg/kg/day parenteral), or in before or after fast ClICG, but enteral feeding produced more positive nitrogen balance. ClICG improved significantly with enteral but not with parenteral feeding.Enteral feeding produces faster nitrogen accrual and reverses the depression of major pathways of bilirubin and organic anion excretion associated with malnutrition. Parenteral feeding failed to improve organic anion clearance despite weight gain.

Many recent clinical studies focus on the critically ill or injured hypermetabolic patient and investigate nutritional factors and regimens that can potentially reduce septic complications and improve clinical outcome. In addition to better defining the amount and type of nutrients appropriate for this population, these studies provide insight into important variables such as route of nutrient administration, supplementation of formulas with immune-enhancing (or nonimmunosuppressive) nutrients, and anabolic agents that promote increased nitrogen retention and lean body mass accumulation.

The optimal duration of antibiotic use in penetrating abdominal trauma is incompletely defined. It is generally accepted that short-term antibiotics are appropriate for low-risk wounds. However, with colon injury and significant degree of injury, abdominal trauma index (ATI) more than 25, concern exists that short-term treatment is not adequate.The study was a prospective double-blind trial of 24-hour treatment (cefoxitin or cefotetan) compared with 5-day treatment in 515 patients. Major abdominal infections (MAI) included abscess, necrotizing fasciitis, and diffuse peritonitis.MAI occurred in 8% of those patients with 1-day therapy and 10% with 5-day therapy. Subgroup analysis of high-risk groups (colon wounds and ATI of more than 25) showed the following MAI rates: colon, 1-day therapy, 14%; 5-day therapy, 15%; ATI of more than 25, 1-day therapy, 17%; 5-day therapy, 30%.Regardless of contamination and degree of injury, 24-hour antibiotic therapy is satisfactory for all penetrating abdominal trauma.

Clostridial soft-tissue infections usually occur from traumatic injury but may be related to unrecognized gastrointestinal malignancy. Overwhelming sepsis with Clostridium septicum developed in five diabetic patients within 24 hours of onset of disease, and their course is reviewed.The personal experience of the author in four cases is reviewed.Patients were seen within 12 to 24 hours of the onset of the disease with painful, rapidly spreading, gas-producing infection of the lower extremity (three patients), upper extremity (one patient), or pelvis (one patient), with severe sepsis in four of five patients. Three of the five patients had pertinent past histories that should have led to the prevention of the disease.Urgent laparotomy should be performed in otherwise healthy diabetic patients who had rapidly progressive, necrotizing, gas-producing infections with no obvious source. Metastatic spread can recur if the focus is not eradicated. All diabetic patients with guaiac-positive stools should have a gastrointestinal evaluation, including colonoscopy if barium enema is normal.

Host defenses within the gastrointestinal tract exclude bacteria and other intraluminal substances, which if released into the systemic circulation, would be toxic to the body. This is accomplished via complex interactions between these external pathogens and local immune responses and nonimmunologic processes. In addition to the mechanical and chemical barriers of the nonimmunologic defense system within the gastrointestinal tract, there is an effective immunologic barrier composed of aggregated and nonaggregated lymphoid cells. Gut-associated lymphoid tissue protects the intestinal mucosa from invading pathogens by intricate pathways of antigen processing. Gut-associated lymphoid tissue also transfers protection to other secretory sites within the body through the common mucosal immune system. The integrity of both the immunologic and nonimmunologic barriers may be affected by any number of pathologic insults as well as by nutritional influences. This article reviews the structural and functional characteristics of this complex and critically important host defense system. Specific nutrient requirements of the immunologic processes are discussed.

Hepatic failure is frequently seen following severe hemorrhagic shock, sepsis, and trauma. Clearance of various drugs has been used to evaluate hepatocellular dysfunction, including indocyanine green (ICG), an organic anionic dye that is transported similarly to bilirubin, and antipyrine (AP), a marker of oxidative phosphorylation. Previous investigators have noted a decrease in ICG excretion following systemic hemorrhage. The effect of isolated hepatic ischemia on the clearances of ICG and AP was studied in 16 pigs after 90 minutes of vascular occlusion to the liver. Antipyrine clearance decreased almost 50% from baseline values at 24 and 72 hours after the ischemia procedure, indicating a significant depression in the cytochrome P-450 system. On the other hand, ICG clearance did not change significantly. In conclusion, ICG clearance is not depressed after isolated hepatic ischemia in pigs. Changes in organic anion clearance after systemic hemorrhage may be because of release of toxic products from ischemic peripheral tissue.

Laryngotracheal trauma (LTT) is a rare but clinically important injury that may be missed without a high index of suspicion. Forty patients with LTT admitted to the University of Tennessee, Memphis from 1984 through 1989 were retrospectively reviewed. Twenty-six patients sustained penetrating (P)-LTT and 14 had blunt (B)-LTT. Three patients with P-LTT and one with B-LTT arrived in full arrest. Sixty-five per cent of blunt injuries, and 100 per cent of penetrating injuries had neck tenderness or overlying evidence of trauma. A combination of angiography, barium swallow, esophagoscopy, CT scan, bronchoscopy and/or laryngoscopy was used for evaluation, depending on the mechanism. Twenty-two of the 23 surviving P-LTT patients underwent surgery; 11 (50%) had concomitant esophageal injury. All patients with complications from P-LTT were in the group with esophageal injury. B-LTT was classified as either mild5, moderate3, or severe6; all 6 severely injured patients had preoperative airway compromise. All complications of B-LTT occurred in the severely injured group. The following conclusions were reached: LTT usually presents with symptoms and/or signs, but they may be minimal and nonspecific. Emergency tracheostomy should not be delayed if ventilation is compromised. Concomitant esophageal injuries are frequent in P-LTT and predispose the patient to postoperative complications. Airway compromise frequently correlates with severity of injury in B-LTT and these patients are also at high risk for complications.

Over a 7-year period, 151 patients with gunshot wounds to the colon surviving beyond 24 hours were managed. The bullet was retained in the body in 66% and exited in 34%. Thirty-four (23%) developed major septic complications (diffuse peritonitis, 21%; intraperitoneal abscesses 24%; and extraperitoneal abdominal abscesses, 56%). The septic complication rate was 26% in the bullet-present group compared with 16% in the remainder (p less than 0.15). The increased septic rate in those with bullets present was the result of abscesses developing around the retained missile. That group with missile abscesses had a lesser degree of injury as measured by the abdominal trauma index compared with the other patients with septic complications (p less than 0.001). Fifteen (79%) of the 19 patients with missile and missile track abscesses had them develop in the psoas muscle. These abscesses occur by fecal contamination of the muscle following inoculation by the bullet, which passes through the large bowel. Computed tomography-guided and operative drainage tend to fail if the foreign body is not removed. Computed tomography-guided or operative drainage should be successful in draining missile track abscesses when the bullet has exited the patient.

This study of the accident scene focuses on the effects of vehicular deformity and restraint devices on occupant injury. In 500 patients evaluated in a Level I trauma center, seatbelts significantly reduced the likelihood of individuals' requiring the trauma center (P less than 0.0001). Seatbelts also significantly reduced the mortality rate of those who were transported to the trauma center (P less than 0.04). Dashboard intrusion correlated with pelvic (P less than 0.001) and femur (P less than 0.03) fractures, closed head injuries (P less than 0.001), and intraabdominal injuries (P less than 0.02). Steering wheel deformity correlated with pelvic fractures (P less than 0.001) and closed head injuries (P less than 0.005). Windshield violation correlated with closed head injuries (P less than 0.014) and spinal fractures (P less than 0.03). Irreparable vehicles correlated with pelvic (P less than 0.0001) and femur fractures (P less than 0.01), closed head injuries (P less than 0.0001) and intra-abdominal injuries (P less than 0.0001). The authors conclude that a careful examination of the accident scene for specific mechanisms of injury can lead to better prehospital care, more rapid and consistent diagnosis of injury, and improved patient outcome. Further prospective studies should accumulate data that will improve prehospital care, alert physicians to possible injury, increase community awareness of injury prevention, and improve vehicle construction.

The Organ Injury Scaling Committee of the AAST recently published a consensus classification of splenic, hepatic, and renal injuries (J Trauma, 29:1664, 1989). The hepatic injury scale (HIS), based on parenchymal laceration and intrahepatic hematoma, includes grades 1 to 6, representing the least to most severe injury. This study classifies liver injuries by findings at celiotomy, correlates operative findings with transfusion requirements and method of management of liver injury, and relates preoperative CT to anatomic findings at laparotomy. Thirty-seven patients with blunt liver injury were evaluated by abdominal CT with and without intravenous contrast and then underwent celiotomy. Increasing operative HIS correlated well with increasing severity of injury as measured by transfusions and operative management. Thirty-one CT grades did not correlate with operative findings (84%). Four patients had intrahepatic hematomas that were not discovered at operation. Twelve lacerations were graded too high by CT and 15 too low. Of these 15, ten CT scores were at least two grades lower than operative findings. Injuries around the falciform ligament occurred in three of the low misclassifications. One patient with intrahepatic hematoma developed hepatic artery pseudoaneurysm. We conclude that the HIS readily characterizes operative findings of hepatic lacerations and that increasing operative grade correlates well with transfusion requirements and operative management. CT can define intrahepatic hematomas, but does not correlate well with hepatic lacerations. Extreme caution is required when using CT alone to define "minimal" liver injury for prospective management of blunt trauma victims.

Over a nine-month period, patients with chest trauma were prospectively evaluated for myocardial contusion. Ninety-two patients with evidence of anterior chest trauma were entered into the study and had 1) an ECG on admission and daily for three days; 2) monitoring of the myocardial band fraction of creatine phosphokinase (CPK-MB) on admission and every eight hours for 24 hours; 3) continuous electrocardiographic Holter monitoring for three to five days; and 4) noninvasive pulsed-Doppler cardiac output measurements daily for three days. Twenty-three patients developed 25 significant arrhythmias (SARRs): 1 atrial fibrillation, 1 AV dissociation, 5 supraventricular tachycardias, and 18 paroxysmal ventricular tachycardias. Cardiac outputs were significantly higher in those patients without SARRs. The CPK-MB levels correlated with the SARRs but were neither sensitive nor specific. No patients required specific therapy and none developed adverse sequelae of the SARRs. We conclude that 1) CPK-MB monitoring should not be routinely used for screening and diagnosis; 2) continuous arrhythmia monitoring deserves further clinical investigation but not routine application; 3) stable patients at risk for myocardial contusion should be monitored for 24 hours; and 4) the Abbreviated Injury Score for "minor" myocardial contusion should be deleted for purposes of ISS tabulation.

Twenty injured patients in the intensive care unit were randomized to receive parenteral nutrition with either 21% (STD) or 46% (HBC) branched-chain amino acids to compare the response of nitrogen balance (NB), somatomedin-C/insulin-like growth factor I (SMC), circulating fibronectin (FBN), and prealbumin (PA). NB was measured and serum collected for SMC, FBN, and PA on days 1, 4, 7, 14, and 21 of nutritional intervention. The treatment groups did not differ significantly for age, weight, injury severity score, trauma score, Apache II score, acute-phase protein concentrations, or type of injury. Comparison of baseline measurements revealed no significant differences in SMC, FBN, or PA. Both groups received similar doses of nonprotein energy and nitrogen. Baseline urea nitrogen excretion was slightly higher in the STD group (216 +/- 55 vs 268 +/- 54 mg/kg/day p = 0.049). Although NB was significantly improved over baseline during subsequent study days, there were no differences between groups after the day-1 measurement. SMC increased significantly from baseline on day 4 in the STD group, on day 7 in the HBC group, and on days 14 and 21 in both groups. There was no significant difference in SMC concentrations between groups on any day. Each group demonstrated a significant increase in PA from baseline on days 7, 14, and 21; however, no difference was seen when groups were compared. FBN increased significantly from baseline on day 14 in the HBC group and on days 7 and 14 in the STD group. FBN measurements were significantly different between groups on day 14 (STD, 179 +/- 71 vs HBC, 229 +/- 59 micrograms/ml; p less than 0.05). NB, PA, SMC, and FBN improve significantly during parenteral nutrition of traumatized patients. With the measured variables, there appears to be no significant difference between STD or HBC amino acids when used as part of parenteral nutrition in injured patients.

The loss of lean muscle mass is one of the hallmarks of protein-calorie malnutrition. Anthropometry is a standardized technique used to assess the response of muscle mass to nutrition therapy by quantifying the muscle and fat compartments. That technique does not accurately reflect actual limb composition, whereas computerized tomography does. Twenty lower extremities on randomly chosen men and women patients were evaluated by anthropometry and computerized tomography. Total area, muscle plus bone area, total volume, and muscle plus bone volume were correlated, using Heymsfield's equation and computerized tomography-generated areas. Anthropometrics overestimated total and muscle plus bone cross-sectional areas at almost every level. Anthropometry overestimated total area and total volume by 5% to 10% but overestimated muscle plus bone area and muscle plus bone volume by as much as 40%. Anthropometry, while easily performed and useful in large population groups for epidemiological studies, offers a poor assessment of lower extremity composition. On the other hand, computerized tomography is also easily performed and, while impractical for large population groups, does offer an accurate assessment of the lower extremity tissue compartments and is an instrument that might be used in research on lean muscle mass.

BMT recipients require large volumes of fluids, drugs and PN. To reduce manipulation of central catheters and the risk of PN line sepsis, both single and double lumen intra-atrial [corrected] catheters were placed in ten BMT recipients through the internal jugular (double lumen) and cephalic or external jugular (single lumen) vein. Patients were observed for two to seven months. Two partially clotted catheters were cleared with intraluminal urokinase. Skin breakdown at two exit sites responded to local care. The nursing staff and patient tolerated the procedure well. During BMT, fluid administration of 4,900 +/- 150 milliliters a day was possible without interruption of PN. Line or catheter site infections did not occur. Use of three intra-atrial [corrected] lumens eased the care of BMT patients and eliminated PN interruption. Decreased line manipulation may also have led to fewer catheter related infections.