Planned ventral hernia. Staged management for acute abdominal wall defects

OBJECTIVE

Analysis of a staged management scheme for initial and definitive management of acute abdominal wall defects is provided.

METHODS

A four-staged scheme for managing acute abdominal wall defects consists of the following stages: stage I--prosthetic insertion; stage II--2 to 3 weeks after prosthetic insertion and wound granulation, the prosthesis is removed; stage III--2 to 3 days later, planned ventral hernia (split thickness skin graft [STSG] or full-thickness skin and subcutaneous fat); stage IV--6 to 12 months later, definitive reconstruction. Cases were evaluated retrospectively for benefits and risks of the techniques employed.

RESULTS

Eighty-eight cases (39 visceral edema, 27 abdominal sepsis, 22 abdominal wall resection) were managed during 8.5 years. Prostheses included polypropylene mesh in 45 cases, polyglactin 910 mesh in 27, polytetrafluorethylene in 10, and plastic in 6. Twenty-four patients died from their initial disease. The fistula rates associated with prosthetic management was 9%; no wound-related mortality occurred. Most wounds had split thickness skin graft applied after prosthetic removal. Definitive reconstruction was undertaken in 21 patients in the authors' institution (prosthetic mesh in 12 and modified components separation in 9). Recurrent hernias developed in 33% of mesh reconstructions and 11% of the components separation technique.

CONCLUSIONS

The authors concluded that 1) this staged approach was associated with low morbidity and no technique-related mortality; 2) prostheses placed for edema were removed with fascial approximation accomplished in half of those cases; 3) absorbable mesh provided the advantages of reasonable durability, ease of removal, and relatively low cost--it has become the prosthesis of choice; and 4) the modified components separation technique of reconstruction provided good results in patients with moderate sized defects.

Acute subdural hematoma: nonsurgical management of selected patients

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.

Is early feeding beneficial? How early is early?

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.

Comparison of specialized and standard enteral formulas in trauma patients

STUDY OBJECTIVE

To compare selected nutrition and immunologic markers and infection in trauma patients receiving a specialized enteral formula with those receiving standard enteral therapy.

DESIGN

Prospective, randomized clinical trial.

SETTING

Level 1 trauma center at a county government hospital.

PATIENTS

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.

INTERVENTIONS

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.

MEASUREMENTS AND MAIN RESULTS

After study entry, patients who received the specialized enteral formula had fewer infections than those receiving standard enteral nutrition (3/19 vs 10/18; p < 0.05). The change in nitrogen balance was significantly better (p < 0.05) 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 (p < 0.05) 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.

CONCLUSION

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.

Failure of topical vegetable oils to prevent essential fatty acid deficiency in a critically ill patient receiving long-term parenteral nutrition

This case report describes the failure of topical vegetable oils containing esters of linoleic acid to prevent essential fatty acid deficiency in a critically ill patient with trauma. A 40-year-old black man injured in a motor vehicle accident developed essential fatty acid deficiency after being maintained on long-term, fat-free parenteral nutrition plus topical vegetable oil application because of the presence of severe hypertriglyceridemia. Biochemical evidence of this deficiency included a decrease in serum linoleic, a-linolenic, and arachidonic acid levels with a corresponding increase in oleic and palmitoleic acid levels. Cutaneous manifestations consistent with this syndrome were also present. After 3 weeks of daily topical treatments with vegetable oils rich in linoleic acid, biochemical abnormalities of deficiency were still evident. Over the following 2 1/2 months, 4% to 22% of the total caloric intake was delivered as intravenous fat in addition to continued topical administration of vegetable oil. Only after supplementation with intravenous fat did the patient demonstrate clinical and biochemical signs of improvement. The results show that cutaneous administration of vegetable oils as the sole source of linoleic acid may be unable to prevent or treat essential fatty acid deficiency in a critically ill surgical patient.

Effect of route of nutrition on recovery of hepatic organic anion clearance after fasting

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Effect of recombinant human insulin-like growth factor I and early total parenteral nutrition on immune depression following severe head injury

OBJECTIVE

To determine the effects of insulin-like growth factor I (IGF-I) and aggressive nutrition on CD4/CD8 ratios following head injury.

DESIGN

Randomized controlled trial.

SETTING

An urban level 1 trauma center.

PARTICIPANTS

Head-injured patients with a Glasgow Coma Scale score of 4 to 10 within 6 hours of hospital admission requiring no major extracranial surgery with the exception of isolated lower-extremity fracture fixation. Fourteen patients were recruited and 11 completed the study.

INTERVENTIONS

Patients were randomized to a continuous infusion of saline or 0.01 mg/kg per hour of recombinant human (rh) IGF-I. Both groups received parenteral nutrition and rapidly advanced to a total protein intake of 2 g/kg per day and a maximum nonprotein calorie intake of 40 kcal/kg per day. The nonprotein prescription was 1.25 times the metabolic energy expenditure determined by metabolic cart not to exceed a nonprotein calorie intake of 40/kcal.

MAIN OUTCOME MEASURES

The CD4/CD8 ratios and serum IGF-I levels on days 1, 7, and 14.

RESULTS

Administration of early aggressive nutrition eliminated the depressed CD4/CD8 ratio usually seen after head injury; administration of IGF-I increased the CD4/CD8 ratio while IGF-I levels were elevated.

CONCLUSIONS

Infusion of rhIGF-I and aggressive early intravenous nutrition affects the immunologic response of patients with severe head injury.

Gut mucosal nutritional support--enteral nutrition as primary therapy after multiple system trauma

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.

Risk of abdominal septic complications after feeding jejunostomy placement in patients undergoing splenectomy for trauma

Compared with total parenteral nutrition, enteral feeding via jejunostomy reduces septic complications in patients with severe trauma. However, violation of the bowel with insertion of a jejunostomy tube may increase the risk of intra-abdominal abscess (IAA), particularly if no simultaneous gastrointestinal tract injury exists. The records of 123 patients requiring splenectomy for trauma at a level I trauma center during a 6-year period (1986 to 1992) were reviewed to examine the incidence of IAA in patients with and without simultaneous jejunostomy placement in the presence and absence of gastrointestinal tract injuries. Thirty patients had jejunostomies placed (J), and 93 did not (NoJ). There were no significant differences between the groups in age, Abdominal Trauma Index, Injury Severity Score, or transfusion requirements. The incidence of IAA was not significantly different between the J and NoJ groups in the presence or absence of gastrointestinal tract injuries. Thus, jejunostomy placement does not increase the incidence of IAA after splenectomy regardless of the presence of a gastrointestinal tract injury.

Empiric monotherapy versus combination therapy of nosocomial pneumonia in trauma patients

Combination therapy for nosocomial pneumonia with a beta-lactam and aminoglycoside is widely accepted because of synergy and reduction of resistant bacteria. This prospective study of 109 trauma patients (94 blunt, 15 penetrating) with nosocomial pneumonia was performed in consecutive phases. In phase 1, patients were randomized to an anti-pseudomonal third-generation cephalosporin--cefoperazone or ceftazidime. Gentamicin was added to each regimen in phase 2. The mean age of the patients was 37 years, the mean ISS was 31, and there were no differences among the four treatment groups relative to associated injuries. Patients receiving monotherapy had a 56% cure rate compared with 31% for combination therapy (p < 0.04). Persistence rates were similar in these two groups (15% and 20%), but superinfection was significantly higher in the combination group (49% vs. 28%; p < 0.04). The predominant superinfecting organism was methicillin-resistant Staphylococcus aureus (MRSA). Nine patients died (5% monotherapy, 10% combination), and eight had a superinfection. We conclude that monotherapy had a higher cure rate than combination therapy for empiric therapy of pneumonia in our trauma patients. Combination therapy failed because of superinfection (primarily MRSA). Emergence of MRSA may be from host overgrowth or plasmid-mediated induction of resistance, possibly caused by gentamicin.

Estimation of the hepatic extraction ratio of indocyanine green in swine

1. The hepatic extraction ratio of Indocyanine Green was measured directly by trans-hepatic catheterization in 14 outbred swine (eight well-fed, six malnourished). A specific two-compartment pharmacokinetic model was fitted to the arterial Indocyanine Green concentration-time data and used to estimate the hepatic extraction ratio of Indocyanine Green. 2. The specific two-compartment pharmacokinetic model was modified to represent more accurately the physiological process of Indocyanine Green removal. Simulations were performed using this new model to estimate the hepatic extraction ratio of Indocyanine Green in the swine. 3. Similarly to previous findings, our data showed that the original model consistently overestimated the hepatic extraction ratio of Indocyanine Green (i.e. the model estimate was compared with the true, directly measured value). 4. The comparison of the modified model and the original model clearly indicates the reason for the overprediction of the hepatic extraction ratio of Indocyanine Green by the latter. The simulations using the new model indicate that the percentage of binding of Indocyanine Green to its transport protein (glutathione S-transferase) for removal in the bile will affect the estimation of the hepatic extraction ratio of Indocyanine Green. Thus, the amount of Indocyanine Green available for removal is less than that assumed by the original model.

Resuscitation of hemorrhagic shock with hypertonic saline/dextran or lactated Ringer's supplemented with AICA riboside

Anesthetized and ventilated swine were bled 23 ml/kg (34% of calculated blood volume) to a mean arterial pressure < 50 mm Hg. After 60 min, a bolus of either 7.5% hypertonic saline/6% dextran 70 (HSD, 4 ml/kg x 5 min) or lactated Ringer's (LR, 32 ml/kg x 5 min) was infused i.v. LR (25-30 ml/kg) was administered to all animals for the next 60 min. Amino imidazole carboxamide riboside (AICAR), which increases endogenous adenosine in ischemic tissues, was added to the initial bolus and the subsequent LR (10 mg/kg bolus + 0.5 mg/kg x 60 min) in half the study population. At 2 hr post-shock, hematocrit, urine output, arterial pressure, pulmonary artery pressure, pulmonary capillary wedge pressure, portal venous O2 saturation, and pulmonary arterial O2 saturation were similar in all groups. With HSD vs. LR, cardiac outputs and stroke volumes were each significantly higher, while right atrial pressures and pulmonary vascular resistances were each significantly lower, which is consistent with augmented cardiac contractility with HSD. Furthermore, systemic oxygen consumptions were significantly higher, and intracranial pressures were each significantly lower with HSD. Nevertheless, no variables were far outside the normal range in either group. The addition of AICAR to LR and HSD eliminated the difference in intracranial pressure, systemic oxygen consumption, reduced heart rate by 30-40 beats/min during the first hour of resuscitation, and increased stroke volume by 20-30%.(ABSTRACT TRUNCATED AT 250 WORDS)

A prospective analysis of diagnostic laparoscopy in trauma

OBJECTIVE

This study was performed to assess current and potential future application for laparoscopy (DL) in the diagnosis of penetrating and blunt injuries. Efficacy, safety, and cost analyses were performed.

SUMMARY BACKGROUND DATA

Diagnostic peritoneal lavage (DPL) and computed tomography (CT) have been the mainstays in recent years for diagnosis of equivocal nontherapeutic laparotomy, whereas CT is not helpful for the vast majority of penetrating wounds. DL may be a useful adjunct to fill in these gaps.

METHODS

Hemodynamically stable patients with equivocal evidence of intraabdominal injury were prospectively entered into the protocol. DL was performed under general anesthesia; patients with wounds penetrating the peritoneum or blunt injury with significant organ injury underwent laparotomy.

RESULTS

Over 19 months, 182 patients (55% stab, 36% GSW, 9% blunt) were studied. No peritoneal penetration was found at DL in 55% of penetrating wounds with 66% of the remainder having therapeutic laparotomy, 17% nontherapeutic laparotomy, and 17% negative laparotomy. Therapeutic laparotomy was performed in 53% of blunt injuries after DL. Tension pneumothorax occurred in one patient and one had an iatrogenic small bowel injury. Charges for DL were $3,325 per patient compared with $3,320 for a similar group undergoing negative laparotomy before this protocol.

CONCLUSIONS

DL is a safe modality for trauma. With current technology, DL is most efficacious for evaluation of equivocal penetrating wounds. Significant cost savings would be gained by performance under local anesthesia. Development of miniaturized optics, bowel clamps, retractors, and stapling devices will reduce overall costs and permit some therapeutic applications for laparoscopy in trauma management.

Pneumonia and stress ulceration in severely injured patients. A prospective evaluation of the effects of stress ulcer prophylaxis

Stress ulcer prophylaxis is a routine aspect of the care of critically injured patients. Recent reports have suggested that patients undergoing prophylaxis with histamine antagonists are predisposed to nosocomial pneumonia, and that treatment with sucralfate can prevent this problem. An open, prospective randomized trial of three regimens was conducted with 278 evaluable patients. The patients were assigned to one of three group: the group receiving sucralfate, the group receiving a cimetidine hydrochloride bolus, and the group undergoing continuous infusion with cimetidine. Stress ulceration developed in 8% of patients in the sucralfate group, 13% of patients in the cimetidine bolus group, and 12% of patients in the cimetidine infusion group, while nosocomial pneumonia developed in 29% of patients in the sucralfate group, 32% of patients in the cimetidine bolus group, and 23% of patients in the cimetidine infusion group. Multivariate analysis of risk factors associated with pneumonia demonstrated independent significance for score on the Glasgow Coma Scale, Injury Severity Score, cord injury, shock, and head injury. Only spinal cord injury was associated with stress ulceration. We conclude that sucralfate and cimetidine are both effective for stress ulcer prophylaxis and that there is no association of cimetidine with nosocomial pneumonia.

Shotgun wounds to the abdomen

In 1963 Sherman and Parrish (Sherman RT, Parrish RA. Management of shotgun Injuries: A Review of 152 Cases. J Trauma 1963;3:76-86) classified shotgun wounds into three types based upon distance and penetration. Because distances are often unknown, we redefined Sherman's groups by pellet scatter. Type I patients had > 25 cm of scatter, Type II had < 25 cm but > 10 cm, and Type III had < 10 cm. Seventy-one abdominal shotgun wound patients were admitted over 8 years. Eight tangential wounds were managed by local wound care. Of the remaining 63, 27 were Type I, 10 were Type II, and 26 Type III. Two Type II and six Type III patients died within 24 hours. All required laparotomy. Nine of the Type I patients required laparotomy; eight had peritoneal signs and one had progressive abdominal tenderness, hypotension, and intra-abdominal pellets. Eighteen Type I patients without peritoneal signs were observed without complications. Type III patients suffered more vascular injuries and presented more frequently with hypotension than Type II patients. Of the patients surviving greater than 24 hours, Type IIIs received more transfusions and stayed longer in the intensive care unit and hospital than Type IIs. They also suffered more complications than Type IIs. Seven Type III patients required complicated reconstruction of the abdominal wall. Classification of abdominal shotgun injuries using pellet spread is a more useful system in determining patient management and prognosis compared to systems based on distance. Type II and III abdominal shotgun injuries require laparotomy, debridement of soft tissue injuries and frequently reconstruction of abdominal wall defects. Type I injuries can be managed effectively using signs of peritoneal irritation or progressive abdominal tenderness as the best indicator of the need for operation.

Occult gastrointestinal malignancies producing metastatic Clostridium septicum infections in diabetic patients

BACKGROUND

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.

METHODS

The personal experience of the author in four cases is reviewed.

RESULTS

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.

CONCLUSIONS

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.

Duration of antibiotic therapy for penetrating abdominal trauma: a prospective trial

BACKGROUND

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.

METHODS

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.

RESULTS

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%.

CONCLUSIONS

Regardless of contamination and degree of injury, 24-hour antibiotic therapy is satisfactory for all penetrating abdominal trauma.

Immunologic structure and function of the gastrointestinal tract

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.

Enteral versus parenteral feeding. Effects on septic morbidity after blunt and penetrating abdominal trauma

To investigate the importance of route of nutrient administration on septic complications after blunt and penetrating trauma, 98 patients with an abdominal trauma index of at least 15 were randomized to either enteral or parenteral feeding within 24 hours of injury. Septic morbidity was defined as pneumonia, intra-abdominal abscess, empyema, line sepsis, or fasciitis with wound dehiscence. Patients were fed formulas with almost identical amounts of fat, carbohydrate, and protein. Two patients died early in the study. The enteral group sustained significantly fewer pneumonias (11.8% versus total parenteral nutrition 31.%, p less than 0.02), intra-abdominal abscess (1.9% versus total parenteral nutrition 13.3%, p less than 0.04), and line sepsis (1.9% versus total parenteral nutrition 13.3%, p less than 0.04), and sustained significantly fewer infections per patient (p less than 0.03), as well as significantly fewer infections per infected patient (p less than 0.05). Although there were no differences in infection rates in patients with injury severity score less than 20 or abdominal trauma index less than or equal to 24, there were significantly fewer infections in patients with an injury severity score greater than 20 (p less than 0.002) and abdominal trauma index greater than 24 (p less than 0.005). Enteral feeding produced significantly fewer infections in the penetrating group (p less than 0.05) and barely missed the statistical significance in the blunt-injured patients (p = 0.08). In the subpopulation of patients requiring more than 20 units of blood, sustaining an abdominal trauma index greater than 40 or requiring reoperation within 72 hours, there were significantly fewer infections per patient (p = 0.03) and significantly fewer infections per infected patient (p less than 0.01). There is a significantly lower incidence of septic morbidity in patients fed enterally after blunt and penetrating trauma, with most of the significant changes occurring in the more severely injured patients. The authors recommend that the surgeon obtain enteral access at the time of initial celiotomy to assure an opportunity for enteral delivery of nutrients, particularly in the most severely injured patients.

Effect of isolated hepatic ischemia on organic anion clearance and oxidative metabolism

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

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.

Correlation of abdominal trauma index and injury severity score with abdominal septic complications in penetrating and blunt trauma

The Abdominal Trauma Index (ATI) was designed to stratify patients with penetrating injuries, and has been used to classify patients with blunt trauma. The Injury Severity Score (ISS) was originally designed to stratify victims of blunt trauma, and it has also been used for victims of penetrating trauma. We attempted to validate the use of ISS and ATI for both penetrating and blunt trauma. A total of 592 penetrating and 334 blunt trauma patients who underwent laparotomy over a 5-year period were evaluated. The overall rate of abdominal sepsis was 7.5% for blunt trauma and 7.6% for penetrating trauma. Mortality (excluding deaths within 48 hours) was 7% for blunt trauma and 1% for penetrating trauma. In the penetrating injury population, an ATI value greater than 15 and an ATI value greater than 25 were significantly associated with abdominal septic complications (ASCs) (p less than 0.001, both comparisons). An ISS greater than or equal to 16 was also associated with ASCs (p less than 0.001). The ASC rate for gunshots was higher than that for stab wounds (11% vs. 2%; p less than 0.001). In the blunt group, an ATI value greater than 15 and an ATI value greater than 25 were associated with ASCs (p less than 0.01 and p less than 0.001, respectively). The association of ASCs and ISS was linear with increasing ISS in patients with blunt abdominal trauma.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of hypoalbuminemia and parenteral nutrition on free water excretion and electrolyte-free water resorption

OBJECTIVE

To measure the effect of human albumin supplementation during parenteral nutrition on serum albumin concentrations, colloid oncotic pressure, free water clearance, electrolyte-free water resorption, and sodium excretion.

DESIGN

Prospective, randomized, controlled trial.

SETTING

Tertiary care center.

PATIENTS

Thirty adult, hypoalbuminemic patients who required parenteral nutrition.

INTERVENTIONS

Parenteral nutrition (control) or parenteral nutrition plus human albumin 25 g/L as a continuous infusion (treatment) for a 5-day study period.

MEASUREMENTS

On days 1 and 5, serum albumin concentration, colloid oncotic pressure, free water clearance, electrolyte-free water resorption, and sodium excretion were measured.

RESULTS

Serum albumin concentrations increased significantly from day 1 to day 5 in both groups (control: 2.0 +/- 0.1 [mean +/- SEM] vs. 2.3 +/- 0.1 g/dL [20 +/- 1 vs. 23 +/- 1 g/L], p = .02; treatment: 2.2 +/- 0.1 vs. 3.5 +/- 0.2 g/dL [22 +/- 1 vs. 35 +/- 2 g/L], p = .0001). Day 5 serum albumin concentrations were significantly higher in the treatment group compared with control (p = .0001). Colloid oncotic pressure increased significantly from day 1 to day 5 in the treatment group (17.8 +/- 0.8 vs. 25.1 +/- 1.0 mm Hg, p = .0001), and was significantly higher than control at day 5 (p = .0001). No significant differences were found for free water clearance, electrolyte-free water resorption, or sodium excretion within or between groups.

CONCLUSIONS

In hypoalbuminemic patients, human albumin supplementation during parenteral nutrition results in significant increases in serum albumin concentrations and colloid oncotic pressure, but has no apparent effect on free water clearance, electrolyte-free water resorption, or sodium excretion.

Effect of nutritional status on organic anion clearance by the swine liver

Hepatic dysfunction follows a wide range of insults. Impaired excretion of organic dyes such as bilirubin often occurs before other obvious clinical defects in metabolic processes. Indocyanine green (ICG) is excreted through pathways similar to those of bilirubin. To determine the effectiveness of ICG as a marker of hepatic dysfunction related to clinical malnutrition, pigs received 5 mg/kg ICG with simultaneous sampling from the hepatic vein, pulmonary artery, and aorta over 3 hours. Group I remained well nourished, group II was fasted to a weight loss equal to 20% of initial body weight, and group III was fasted to a 20% weight loss and then refed until the animals regained their initial weight. Both systemic and intrinsic hepatic clearance were depressed significantly with fasting but returned above baseline after refeeding. No significant difference appeared between systemic and intrinsic hepatic clearance. Extraction ratios were low in all groups. In outbred swine, ICG clearance reflects the function of hepatic organic anion excretion in vivo, and venous sampling reflects intrinsic hepatic clearance. The impairment of the carrier-mediated transport system is reversible with refeeding.