Aphysiologic performance on dynamic posturography.

The remarkable ability of the body to maintain balance is the result of central nervous system integration of sophisticated inputs from the vestibular, visual, and somatosensory systems. Strategies by patients with balance dysfunction are aphysiologic when their performance is relatively better on more difficult conditions of sensory conflict than on easier ones. Twenty-two aphysiologic patterns on computerized dynamic posturography were compared with age-matched normal and vestibular patterns. The aphysiologic group performed significantly better than the patients in the vestibular dysfunction group on the most difficult subtests of computerized dynamic posturography, conditions 5 and 6, yet significantly poorer on the easier subtests, conditions 1 through 4. In addition, patients in the aphysiologic group tended to show greater intertrial variability compared with patients in both normal and vestibular system dysfunction groups. A stepwise linear discriminant analysis was used to determine a set of conditions that had significant value in discriminating between the three patient groups. Case studies are presented to further illustrate the clinical usefulness of computerized dynamic posturography testing in the evaluation of patients suspected of having a functional component to their on-feet balance problems.

Acute ethanol intoxication increases the risk of infection following penetrating abdominal trauma.

Acute alcohol (ETOH) intoxication as a risk factor for infection in trauma victims to our knowledge has not been previously reported. To determine if ETOH intoxication increases infection risk we examined data from 365 patients with penetrating abdominal trauma who were enrolled in a multi-center antibiotic study. Ninety-four patients sustained an injury to a hollow viscus. To separate acute from chronic ETOH effects, infections were divided into two categories: (1) trauma related; infections caused by bacterial contamination at the time of injury, while blood alcohol level (BAL) was elevated. (2) nosocomial; infections caused by bacteria acquired during hospital stay, after BAL had normalized. A BAL > or = 200 mg/dL was associated with a 2.6-fold increase in trauma-related infections. There was no association between BAL and subsequent nosocomial infection. Since infection rates for intoxicated patients were not higher after BAL had normalized, acute rather than chronic effects of ETOH appear to be responsible.

Enhancement of erythropoiesis by recombinant human erythropoietin in low birth weight infants: a pilot study.

We randomly assigned eight concurrently symptom-free premature infants (birth weight less than or equal to 1250 gm) at high risk of requiring erythrocyte transfusions for anemia of prematurity to 6 weeks of intensive treatment with either subcutaneous recombinant human erythropoietin (r-HuEPO group) or a placebo (control group). Treatment with r-HuEPO was initiated at a dose of 100 units/kg per day 5 days a week, and was increased to 200 units/kg per day after 2 or 3 weeks if target reticulocyte counts were not achieved. All patients were given supplemental oral iron therapy at a dose of 6 mg/kg per day, as tolerated. Mean reticulocyte counts in r-HuEPO-treated and control infants were 64,600 versus 67,500 cells/mm3 at entry; were 245,600 versus 78,000 cells/mm3 after 1 week; and averaged 262,600 versus 136,400 cells/mm3 during the study. Mean reticulocyte counts in r-HuEPO-treated infants were 251,200 cells/mm3 during the week when r-HuEPO, 100 units/kg per day, was given, and were 269,500 cells/mm3 after the dose was increased to 200 units/kg per day. Mean hematocrit values at entry were 33.4% in babies who received r-HuEPO versus 33.6% in the control subjects, and were 31.4% in r-HuEPO-treated and 25.2% in the control subjects at the end of treatment. One r-HuEPO-treated and three control babies received transfusions during the study; the total volume of blood given was 17 ml in the r-HuEPO group and 101 ml in the control subjects. The percentage of hemoglobin F increased in infants not given transfusions. We conclude that r-HuEPO stimulates endogenous erythropoiesis in small premature babies who are receiving supplemental oral iron therapy. A controlled multicenter trial has been undertaken to confirm these promising preliminary observations.

Risk of infection after open fracture of the arm or leg.

Two hundred forty consecutive patients admitted for operative treatment of an open fracture of the arm or leg were followed up prospectively for the development of fracture infection. The independent risk of fracture infection was increased in patients with grade IIIB or IIIC fractures, internal or external fixation, lower-leg fracture, any blood transfusion, or injuries resulting from motorcycle accidents or motor vehicle-pedestrian accidents. By stepwise multivariate logistic regression, the most significant risk factors were the grade of the fracture, internal or external fixation, and fractures of the lower leg. These risk factors all represent local wound characteristics, and we conclude that the most important actions by the surgeon to prevent infection involve local wound care. There was no relation between the timing of antibiotic administration or duration of antibiotic therapy and infection risk.

Strain in the lateral ligaments of the ankle.

Strain was measured in the normal anterior talofibular ligament (ATF) and the calcaneofibular ligament (CF) using Hall effect strain transducers in five cadaveric ankles. These measurements were made in both ligaments with the ankle in neutral position and with the foot moving from 10 degrees dorsiflexion to 40 degrees plantarflexion in an apparatus that permits physiologic motion. The ankle ligaments were then tested with the foot placed in six different positions that combined supination, pronation, external rotation, and internal rotation. In the neutral position, through a range of motion of 10 degrees dorsiflexion to 40 degrees plantarflexion, the anterior talofibular ligament underwent an increasing strain of 3.3%. No significant strain increase was found with internal rotation. The only significant difference from the strains at the neutral position was in external rotation, which decreased strain 1.9%. In all positions, increased strain occurred with increased plantarflexion. The calcaneofibular ligament was essentially isometric in the neutral position throughout the flexion arc. The calcaneofibular ligament strain was significantly increased by supination and external rotation. However, with increasing plantarflexion in these positions, the strain in the calcaneofibular ligament decreased. Therefore, plantarflexion has a relaxing effect on the calcaneofibular ligament. Thus, the anterior talofibular and calcaneofibular ligaments are synergistic, such that when one ligament is relaxed, the other is strained and vice versa.

Hand infections. Bacteriology and treatment: a prospective study.

In a prospective, double-blind study, 193 patients hospitalized for established hand infections were randomized to receive either cefamandole intravenously followed by cephalexin by mouth or methicillin intravenously followed by dicloxacillin by mouth. Careful aerobic and anaerobic cultures were performed. Multiple organisms grew in cultures from 84% of the patients (over three isolates per infection on average). Human bite wounds contained anaerobes 43% of the time compared with 12% for other wounds. The majority of wounds (72%) required operative treatment. In 128 patients assessable for treatment outcome, results were unsatisfactory in 11 (9%). There was no difference in outcome between cefamandole (6/59, 10%) and methicillin (5/59, 8%). The presence of anaerobes, Eikenella corrodens, human bites, or an increasing number of organisms was associated with an unsatisfactory response. The presence of Staphylococcus aureus and/or beta-hemolytic streptococci was associated with a favorable response. The incidence of antibiotic-resistant isolates did not correlate with outcome.

Duration of preventive antibiotic administration for open extremity fractures.

The necessary duration of antibiotic administration after open fracture has not been established. In a double-blind prospective trial we randomized 248 patients with open fractures to receive one or five days of cefonicid sodium therapy or five days of cefamandole nafate therapy as part of the initial treatment. Rates of fracture-associated infections in the three groups were ten (13%) of 79, ten (12%) of 85, and 11 (13%) of 84, respectively. The 95% confidence limit for the difference in infection rates between the one-day group and the combined five-day groups was 0% to 8.3%. The actual difference was 0.2%. A brief course of antibiotic administration is not inferior to a prolonged course of antibiotics for prevention of postoperative fracture-site infections.

Enteral versus parenteral nutritional support following laparotomy for trauma: a randomized prospective trial.

Although enteral nutrition is considered more 'physiologic' than parenteral nutrition, there is greater published experience with parenteral nutrition in trauma patients. To compare the efficacy of these two techniques, we prospectively randomized multiple trauma patients during their admission laparotomy to receive either central venous parenteral nutritional (TPN: n = 23) or enteral nutrition by jejunostomy (Jej: n = 23). Nutritional support began on the first postoperative day; the study period continued a maximum of 14 days. There were no significant differences between the two groups in age, sex, injury severity, estimated caloric needs (3,322 TPN; 3,114 Jej), hours to achieve full prescription (77 PTN; 79 Jej), or the number of days on nutritional support (22 TPN; 25 Jej). Average daily caloric intakes, nitrogen balance results, and complication rates were also comparable. These results suggest that early postoperative jejunostomy feeding is a safe and efficacious choice for multiple trauma patients undergoing laparotomy.

Efficacy of short-course antibiotic prophylaxis after penetrating intestinal injury. A prospective randomized trial.

Infection is the leading cause of morbidity and mortality occurring more than 48 hours after penetrating abdominal injury. Antibiotics are routinely administered to patients with penetrating intestinal injuries and are usually given for five days or more. We randomized 116 patients with confirmed penetrating injuries of the colon and/or small bowel to receive either 12 hours or five days of antibiotics. Age, sex, weapon, severity of injury, and other risk factors were evenly distributed between groups. Twenty-one patients (18%) developed trauma-related infections, 28 (24%) any infection, and three (2.6%) died. There were no significant differences between groups in any category of outcome. For patients with penetrating intestinal or colonic injury, a 12-hour course of antibiotics is as effective as a five-day course and has the advantage of lower cost and, theoretically, fewer side effects.

Stratified outcome comparison of clindamycin-gentamicin vs chloramphenicol-gentamicin for treatment of intra-abdominal sepsis.

A randomized, prospective trial was conducted of 93 patients with operatively confirmed intra-abdominal sepsis. The study compared clindamycin-gentamicin and chloramphenicol-gentamicin for treatment of carefully stratified patient groups. Malnutrition, age over 65 years, shock, alcoholism, gastrointestinal tract bleeding, steroid administration, diabetes, obesity, and organ malfunction were present with equal frequencies in each group. The duration of antibiotic treatment averaged 8 1/2 days, and the average length of postoperative hospitalization was 29 days. Study antibiotics were changed for bacteriologic reasons in 11 patients taking clindamycin-gentamicin and 12 patients taking chloramphenicol-gentamicin (25% of the total), and two patients in the clindamycin-gentamicin group had a minor adverse reaction. Initial satisfactory clinical responses were obtained in 59 (63%) patients. Twenty-five patients (27%) subsequently developed unsatisfactory courses, but 48 (52%) patients remained well through the 30-day period. Septic-related mortality occurred in 18 (19%) patients, and two (2%) patients had unrelated deaths. There were no significant differences between the study regimens by the outcome criteria evaluated.

Surgical infection stratification system for intra-abdominal infection. Multicenter trial.

One hundred eighty-seven patients treated for established intra-abdominal infection in five medical centers were studied using the surgical infection stratification system. This system combines an anatomic category with a numerical estimate (acute physiology score [APS]) of deviation from normal of 33 routine laboratory tests or physical findings. Overall mortality was 24% and the rate of treatment "success" with a single operation and single course of antibiotics was 48%. Eighty percent of deaths occurred with infection present. Multivariate analysis disclosed that APS, malnutrition, and age were most noteworthy for predicting survival or death. Intra-abdominal infection carries substantial mortality and morbidity despite advances in understanding the underlying pathophysiologic condition. Additional clinical studies are needed. Uniform reporting criteria, including the use of an objective severity scoring system, are suggested for future reports concerning intra-abdominal infection.

Risk of infection following laparotomy for penetrating abdominal injury.

We analyzed the occurrence of putative risk factors for postoperative infection in 338 patients who underwent emergency laparotomy for penetrating abdominal injury. Mortality was 3%, with nine of ten deaths directly related to infectious complications. Gunshot wounds and colon injuries occurred more frequently in the patients who died than in survivors. Stepwise discriminant analysis revealed that transfusion requirement, length of operation, age, and the penetrating abdominal trauma index were the most significant risk factors for any infection. Other risk factors examined (shock, number of organs injured, mode of injury, and chest injury) did not contribute any additional information. Colon injury was more prevalent in patients with trauma-related infections than in those with nosocomial infections.

Determinants of organ malfunction or death in patients with intra-abdominal sepsis. A discriminant analysis.

One hundred and six patients found at operation to have intra-abdominal sepsis were prospectively followed up to determine the incidence of organ malfunction and death. These outcomes were correlated with age, preexisting disease, underlying cause of sepsis, shock, nutritional status, and alcoholism. Organ malfunction occurred in 31 patients (29%), 19 (61%) of whom died. Two (3%) of 75 patients without organ malfunction died. Discriminant analysis revealed a significantly increased risk of death in patients with shock at any time, age greater than 65 years, alcoholism, bowel infarction, or malnutrition. A discriminant equation based only on preoperative variables correctly assigned the outcome of death or survival in 97 (92%) of the patients based on probabilities derived from this analysis. At present, this information is primarily of interest for researchers comparing outcomes in groups of patients, but with additional refinements it may become clinically useful for individual patients.

Duration of preventive antibiotic administration for penetrating abdominal trauma.

Eighty-two patients with penetrating abdominal trauma and visceral injuries requiring laparotomy were prospectively randomized to receive either 12 hours or five days of penicillin G potassium and doxycycline hyclate beginning before operation. Distribution between groups was equivalent for all risk factors except shock, which was more prevalent in the 12-hour group. Antibiotics were first administered an average of 64 minutes following injury, and 90% of all patients had received antibiotics and were being operated on within 3 hours 15 minutes. Overall infection rates were 17% in patients with colon penetration, 14% in patients without colon penetration but with other intestinal penetration, and 0% in patients without intestinal penetration. Twelve-hour and five-day antibiotic regimens were comparable in the prevention of postoperative infectious complications following penetrating abdominal injuries. Intestinal penetration was the most important risk factor for developmental of infectious complications in this patient population.

Implications of leukocytosis and fever at conclusion of antibiotic therapy for intra-abdominal sepsis.

Outcomes of 65 patients after operation who had exhibited a clinical response to treatment for intra-abdominal sepsis were compared based on the presence or absence of leukocytosis and fever at the conclusion of antibiotic therapy. Fifty-one patients were afebrile when antibiotics were stopped. Intra-abdominal infection developed in 7 of 21 (33%) who had a persistent leukocytosis, but no intra-abdominal infections developed after operation in 30 patients who had normal WBC counts at the end of antibiotic treatment (p less than 0.005). Nosocomial infections developed in 6 (12%) of the 51 patients, and there was no difference in the incidence between patients with or without leukocytosis. Eleven of 14 (79%) patients who were still febrile when antibiotics were discontinued developed infections after operation. Nosocomial infections occurred in three (21%) and intra-abdominal infections in eight (57%). Of the 15 patients who developed intra-abdominal infection after operation, only four responded to appropriate antibiotic treatment without requiring further surgery. The other patients required surgical management for definitive control within two months of the initial operation. In conclusion, patients at risk of developing infection after operation after exhibiting a clinical response to treatment of intra-abdominal sepsis are those who are afebrile with a persistent leukocytosis or who are still febrile when antibiotics are stopped.

Leukocytosis at termination of antibiotic therapy: its importance for intra-abdominal sepsis.

Postoperative outcomes of 31 afebrile patients who had responded to treatment for intra-abdominal sepsis were compared based on the presence or absence of leukocytosis (WBC count greater than 10,000/cu mm) at the conclusion of antibiotic therapy. In 68% of the patients who had leukocytosis, postoperative septic complications developed within two months of their operation. In patients without leukocytosis, complications developed in only 8.3%. Afebrile patients who exhibit leukocytosis but have responded clinically to treatment are at risk for postoperative infection and multisystem failure.