Neutrophil function in a rat model of endotoxin-induced lung injury.

Polymorphonuclear neutrophil leukocytes (PMNs) are known to cross the alveolar-capillary barrier and enter the alveolus in acute adult respiratory distress syndrome (ARDS). The pathogenic role of PMNs in both the acute lung injury and subsequent infectious susceptibility in ARDS is not clear. In the present study we investigated the functional status of various neutrophil populations using a chronic, endotoxemia-induced ARDS model. Rats infused with Escherichia coli endotoxin for three days develop an acute lung injury with a histologic picture closely resembling human ARDS. The PMNs recovered from the circulation and by bronchoalveolar lavage were compared with normal rat PMNs. In endotoxemic animals, superoxide production was markedly enhanced in circulating PMNs, indicating production of high levels of potentially cytotoxic oxygen intermediates, while myeloperoxidase activity was decreased in both circulating and lavage PMNs, indicating depressed myeloperoxidase-dependent antimicrobial activity.

Intraoperative abdominal ultrasonography: initial experience with a dedicated high-resolution operative transducer.

A dedicated 8-MHz intraoperative scanning probe was used in 42 patients who underwent exploratory abdominal surgery. A variety of pathologic processes involving the liver, pancreas, bowel, and biliary and genitourinary systems were evaluated. Sonographic studies were evaluated to determine if they added new information (20 patients, 47.6 per cent), confirmed known information (20 patients, 47.6 per cent), or provided false information (two patients, 4.8 per cent). Preliminary experience with a specially developed transducer suggests that its design avoids many of the difficulties encountered with other transducers employed for this technique. Intraoperative sonography has, in many instances, the potential to simplify surgery, shorten operating time, and modify the type of surgical procedure performed.

Resident and faculty differences in student evaluations: implications for changes in a clerkship grading system.

Data were collected for 163 students completing a surgical clerkship including scores on patient write-ups, ward performance evaluations, oral examinations, and National Board of Medical Examiners (NBME) Surgery subscores. Oral examination scores and patient write-ups were rated from 74 (failing) to 100 (honors) by faculty members. The ward performance evaluation included ratings on nine components of ward performance from 1 (unsatisfactory) to 4 (superior) and an overall ward score of 74 (failing) to 100 (honors). Similarities and discrepancies in the way that evaluators viewed clerks were found. Weights given to ward component ratings in relationship to the overall ward score were equivalent for faculty members and residents. Residents rated clerks higher than faculty members on five ward components. Faculty ratings were poorly correlated with resident ratings. Faculty members and residents gave different ratings to the same students in contrast to the similarities in which faculty members and residents gave weight to the ward component ratings. Resident ratings were better than faculty ratings in predicting the NBME Surgery subscore. Although these results suggest that residents are better evaluators of a clerk's performance than are faculty members, other studies indicated the opposite. The elimination of participation of either faculty or residents in the grading of students is unwise. Periodic monitoring of evaluation practices is necessary to ensure fairness in grading procedures.

Intraoperative US as an aid to intraoperative electron beam radiation therapy.

Intraoperative electron-beam radiation therapy (IRT) is being used to treat certain abdominal malignancies. Accurate determination of tumor size, depth, and extent is necessary to select a treatment cone of appropriate size and appropriate electron beam energy for the treatment portal. Fourteen patients undergoing evaluation for this treatment were examined with intraoperative ultrasonography (IUS) to aid therapy planning. IUS study required little additional time and readily delineated tumor size, depth, and relationship to adjacent structures. In two patients, the US and operative findings provided information that precluded use of IRT. The traditional method of tumor evaluation by intraoperative palpation and inspection was consistently enhanced by the use of IUS findings. IUS is a valuable adjunct that improves the accuracy of therapy planning for IRT.

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.

Postoperative wound infection surveillance by use of bacterial contamination categories.

A prospective 2-year surveillance of 7129 wounds was conducted on all surgical services of the University Hospital in Seattle to determine the postoperative infection rates by surgical wound category. Rates on all services for clean (0.8%), clean-contaminated (3.4%), contaminated (3.6%), and dirty (9.9%) wounds were recorded and compared to rates reported in the surgical literature. The overall wound infection rate was 1.7%. When the incidence of infection for a specific service in a category was observed to be in excess of a previously reported upper rate, patient charts were critically reviewed to determine if host, pathogen, or technical factors could be implicated in the excessive infection rates. Extending postoperative wound surveillance to include critical chart analysis in these categories provides hospital staff members responsible for infection control the opportunity to organize corrective measures against excessive rates in a broader category of wounds.

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.

Desmoid tumor complicating remobilization treatment for a chronic pain syndrome.

The criteria for recommending an operant conditioning program for a patient with chronic pain include definable pain behavior. A thorough investigation of all organic factors that may contribute to pain is usually made prior to such treatment. This report describes a patient with chronic pain and mild cognitive deficits related to a truck accident who insidiously developed an extra-abdominal desmoid tumor. Desmoid tumors, which may develop after trauma, are associated with incidental connective tissue anomalies. They can be initially mistaken for fibrocytic nodules because they have a distribution similar to that in fibromyalgia. This patient's painful tumor was diagnosed while he was participating in a remobilization program. Subsequent resection and irradiation adversely affected rehabilitation goals and reinforced the patient's conviction that all his complaints were organically based.

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.

Diagnosis and treatment of retroperitoneal perforation complicating the double-contrast barium-enema examination.

A case of retroperitoneal air caused by rectal perforation during a double-contrast barium-enema examination is reported. In 9 similar reported cases, radiographic signs included perirectal, mediastinal, and cervical emphysema. Because of the frequent absence of clinical signs, radiographic recognition may be crucial for prompt management. Reported experience suggests that asymptomatic patients with these radiographic findings may be managed with hospitalization and close observation rather than immediate laparotomy.

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.

Prophylactic antibiotics in surgery: a rationale for the family physician.

Antibiotic administration can effectively reduce the risk of postoperative wound infection under specific circumstances. Maximal protection is obtained when an antibacterial concentration of a bacteriologically appropriate antibiotic regimen is circulating within target tissues at the time of bacterial contamination. This protection is obtained during a finite period, usually not exceeding four hours following bacterial seeding of tissues. The preservation of intact host defense mechanisms is of ultimate importance in preventing wound infection. When defenses are compromised or when an inoculum is of a size that can overwhelm host defenses, the perioperative administration of antibiotics can significantly reduce infection risk. However, antibiotic use must not lead to a relaxation of good surgical judgment and technique.

Role of home total parenteral nutrition in management of obliterative peritonitis.

Two patients with obliterative peritonitis complicating enterocutaneous fistulae received total parenteral nutrition prior to surgical closure. One patient managed on home parenteral nutrition for 8 mo experienced psychosocial and nutritional rehabilitation at a daily cost of $37. Experience with the other patient confirmed that a significant resolution of obliterative inflammatory changes can occur during a 4-mon period of bowel rest when septic foci have been drained adequately. In-hospital management was required by this patient, and daily charges greatly exceeded those accrued by the other patient who could be managed at home. A home parenteral nutrition program is a cost-effective means of providing time for resolution of obliterative peritonitis.

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.

Use of an immunoperoxidase method for identification of Bacteroides fragilis.

An indirect immunoperoxidase (IP) slide test was evaluated for the laboratory identification of Bacteroides fragilis. Antigen-antibody complexes were detected with goat anti-rabbit immunoglobulin G-peroxidase conjugate with 3-amino-9-ethyl-carbazole as the peroxidase substrate. Ninety-one percent of 44 B. fragilis strains tested were IP positive (3+ to 4+ reactions) with greater than or equal to 1:160 dilutions of rabbit antiserum produced against whole cells of B. fragilis ATCC 23745. The antiserum was species specific. No cross-reactions were observed with 35 Bacteroides strains of other species or with a variety of facultative or aerobic gram-negative bacilli. Four B. fragilis strains were IP negative. One of these (VPI 2393) was the deoxyribonucleic acid (DNA) homology group II reference strain. The other three were clinical isolates. IP-negative and representative IP-positive strains were tested for DNA homology with the type strains for DNA homology groups I and II (VPI 2553 and VPI 2393). Two of the three clinical isolates were classified as DNA homology group II, and the remaining strain was classified as a group I. Capsular material known to be unique to B. fragilis was common to both DNA homology groups as indicated by reactions with purified anticapsular antiserum. The IP technique provides a suitable alternative to fluorescent microscopy for the rapid immunological identification of B. fragilis.