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Biomedical subjects

R L Nichols

Publications and source records attributed to R L Nichols.

At least 73 records · Page 4Linked to original sources
PubMed1987

Coagulopathy associated with extended-spectrum cephalosporins in patients with serious infections.

Patients enrolled in two double-blind multicenter studies were evaluated for the development of hypoprothrombinemia during treatment with cephalosporins. Patients with pneumonia or peritonitis received ceftizoxime, cefotaxime, or moxalactam. The incidence of hypoprothrombinemia was greater in patients with peritonitis (12 of 49) than in those with pneumonia (5 of 96; P less than 0.05). Overall, moxalactam was associated with a higher incidence of hypoprothrombinemia (13 of 52) than either ceftizoxime (1 of 43; P less than 0.05) or cefotaxime (3 of 50; P less than 0.05), and moxalactam patients incurred the highest average increase in prothrombin time (3.7 s) as compared with either ceftizoxime (0.5 s; P less than 0.05) or cefotaxime (0.9 s; P less than 0.05) patients. The occurrence of hypoprothrombinemia in moxalactam patients with peritonitis was not related to dosage, duration of therapy, age, sex, race, or renal or hepatic function. The degree of ileus was, however, strongly related to the development of coagulopathy in moxalactam-treated patients only.

Adolescent↗
PubMed1987

Intra-abdominal sepsis: controversies and choices in management.

Contamination of the peritoneal cavity may lead to generalized peritonitis or abscess formation. Both aerobic and anaerobic bacteria participate in the infectious process. The concentration and the particular mix of aerobes and anaerobes depends on the site of perforation, with the highest concentrations and greatest predominance of anaerobes in the colon. A number of factors contribute to the risk of infection, and a formula has been devised for calculating a given patient's risk for infection following intestinal perforation secondary to penetrating abdominal trauma. The goal of therapy is to reduce morbidity, mortality, and duration of hospital stay. Specific techniques used to achieve this goal are controversial. In essence, the keys to successful management of intra-abdominal sepsis are early diagnosis and surgical intervention, supplemented by systemic antibiotics that are effective against the aerobic and anaerobic components. Considerations in choosing antibiotics are efficacy, safety, and cost-effectiveness. Some second-generation and third-generation cephalosporins often offer an effective, safer, and more economical alternative to antibiotic combinations.

Animals↗
PubMed1986

Management of intra-abdominal sepsis.

Intra-abdominal sepsis most frequently follows penetrating or blunt abdominal trauma or perforated appendicitis or diverticulitis. The initial leakage of the endogenous gastrointestinal microflora into the peritoneal cavity results in peritonitis and secondary septicemia, which is frequently followed by localized intra-abdominal abscess. These infections are most frequently polymicrobial and relate directly to the unique endogenous microflora at the various levels of the gastrointestinal tract. The treatment of intra-abdominal sepsis is primarily centered around prompt, appropriate surgical intervention. Parenterally administered antibiotics are also required to decrease the chance of local bacterial infection or septicemia. The choice of the appropriate agent(s) to be used initially, before the results of culture and sensitivity reports are available, depends primarily on the clinical presentation and also on whether the intra-abdominal infection occurred in the community or within the hospital setting. Clinical and experimental studies of intra-abdominal sepsis have largely stressed the use of antibiotic agents that have a spectrum of activity effective against the aerobic coliforms and anaerobic Bacteroides fragilis.

Abdomen, Acute↗
PubMed1985

Inhibition of beta-lactamase-induced resistance in soft-tissue infections.

Sulbactam ([CP45,899] penicillanic acid sulfone) inhibits many of the beta-lactamases commonly found to be the cause of penicillin resistance. This agent was combined with either penicillin G potassium or ampicillin sodium in the treatment of 97 patients admitted with serious soft-tissue infections. Fifty-one of the infections were caused by at least one bacteria resistant to the antibiotic alone. Staphylococcus aureus was the most common pathogen (48 isolations) followed by the coliforms (30 isolations). Ninety percent of the isolates that were tested produced beta-lactamase. Susceptibility studies showed a high degree of resistance to the penicillin alone that was significantly lowered by the addition of sulbactam. The overall clinical results showed 81% of the infections to be either well controlled or cured. Three patients failed to show improvement. Thirteen patients showed transitory increases relatively safe and efficacious in the treatment of soft-tissue infection caused by penicillin-resistant and penicillin-susceptible organisms.

Abscess↗
PubMed1985

Adverse effect of splenectomy in experimental peritonitis.

Patients undergoing splenectomy have increased operative morbidity and mortality, especially when associated with gastrointestinal surgery or injury. This present study was designed to assess the effect of splenectomy on mortality in a polymicrobial fecal peritonitis model and evaluate therapy with antibiotic (cefoxitin) or immunomodulation (glucan). Human stool-barium (0.15 cc) was placed in the peritoneum of Sprague-Dawley rats at the time of splenectomy or sham surgery. Splenectomy animals were then treated with 5% dextrose, cefoxitin (60 mg im q 6 hr), glucan (7.5 mg ip prior to surgery), or cefoxitin plus glucan. Splenectomy resulted in decreased survival (5% vs 30%, P less than 0.05). Treatment with cefoxitin (90%) or glucan (47%) significantly improved survival. Combined glucan-cefoxitin therapy had no improvement over cefoxitin alone. Peritoneal and blood cultures were performed 12 hr postoperatively. There were no significant differences in growth of bacteria between sham and splenectomy animals. Cefoxitin treatment resulted in lower growth of bacteria from both blood and peritoneum (P less than 0.05). Glucan treatment caused a significant decrease in the number of bloodborne bacteria (P less than 0.05). Intravascular colloidal carbon clearance and leucocyte counts were performed at 12 hr postoperatively. Presence of peritonitis significantly enhanced intravascular clearance, while splenectomy had no effect. Addition of glucan or cefoxitin therapy to splenectomy animals did not enhance intravascular clearance. Leucocyte counts were significantly lower (P less than 0.05) when splenectomy was added to peritonitis animals. Glucan and cefoxitin therapy did not increase leucocyte counts. Based on these studies we conclude that (1) splenectomy increases mortality in fecal peritonitis, (2) antibiotic and immunomodulator afford some protection, and (3) exact mechanism of protection remains unclear.

Adjuvants, Immunologic↗
PubMed1985

Aminoglycoside peritoneal lavage: lack of efficacy in experimental fecal peritonitis.

The utility of an adjunctive aminoglycoside lavage in the prevention of intra-abdominal abscesses utilizing an experimental rodent model was studied. Peritonitis was created in 115 rats by the intra-abdominal placement of gelatin capsules containing a barium-sulfate, human stool mixture. Four hours later, the animals were re-explored and lavaged with 30 ml/kg of sterile saline. Following the lavage, they were randomized to receive 15 ml/kg of either a 0.2% gentamicin or a normal saline lavage. The animals were then treated with intramuscular gentamicin-clindamycin or saline placebo for nine days. There was no difference in the number of abscesses between the groups receiving systemic antibiotics. The addition of gentamicin to a peritoneal lavage did not decrease the incidence of intra-abdominal infection in animals receiving effective systemic antibiotics.

Abdomen↗
PubMed1985

Clostridial sepsis: unusual clinical presentations.

We present four cases exhibiting the widely diverse nature of clinical infections due to anaerobic Clostridium perfringens. These cases exemplify the need for a thorough initial physical examination, immediate Gram staining of fluid from involved tissue, and recognition of the severity of the disease in any patient who has early septic deterioration after elective or emergency surgical procedures. Management of these infections includes both high-dose parenteral penicillin therapy and aggressive initial surgical debridement of all involved tissues.

Adult↗
PubMed1984

Risk of infection after penetrating abdominal trauma.

To identify the risk factors for the development of postoperative septic complications in patients with intestinal perforation after abdominal trauma, and to compare the efficacies of single-drug and dual-drug prophylactic antibiotic therapy, we studied 145 patients who presented with abdominal trauma and intestinal perforation at two hospitals between July 1979 and June 1982. Logistic-regression analysis showed that a higher risk of infection (P less than 0.05) was associated with increased age, injury to the left colon necessitating colostomy, a larger number of units of blood or blood products administered at surgery, and a larger number of injured organs. The presence of shock on arrival, which was found to increase the risk of infection when this factor was analyzed individually, did not add predictive power. Patients with postoperative sepsis were hospitalized significantly longer than were patients without infection (13.8 vs. 7.7 days, P less than 0.0001). Both treatment regimens--cefoxitin given alone and clindamycin and gentamicin given together--resulted in similar infection rates, drug toxicity, duration of hospitalization, and costs.

Abdominal Injuries↗
PubMed1984

Prevention of infection in high risk gastrointestinal surgery.

Postoperative infectious complications are a frequent cause of morbidity and mortality in the surgical patient. These septic events, which are usually confined to the surgical wound, may involve deeper structures or the bloodstream. The highest incidence of these complications in the patient undergoing elective operation occurs after gastrointestinal surgery, in which the endogenous bacterial populations are usually the causative microorganisms. The economic, physical, and psychological impact of postoperative infections mandates the use of preventive methods to decrease the incidence of such untoward events. In this clinical setting, sound surgical judgment and proper technique are most important. The use of appropriately chosen and administered prophylactic antibiotics also has proved of great benefit in many of these patients.

Anti-Bacterial Agents↗
PubMed1983

Contaminated street heroin. Relationship to clinical infections.

Thirty-one samples of street heroin were analyzed bacteriologically and chemically as to their microbial burden and chemical adulterants (fillers). Sixty-one percent of the samples were positive for microbial growth. Many species were isolated from the positive samples with Bacillus sp (79%) and Aspergillus sp (10%) predominating. The level of contamination ranged from 1.6 X 10(2) to 3.7 X 10(4) organisms per gram. We obtained cultures from 16 addicts from the Chicago area and 21 from the New Orleans area who had soft-tissue infections related to their habit. Infections in this group of patients were usually polymicrobial; however, there was no correlation between the organisms recovered from street heroin and the addicts' infections. Most drug-related infections appear to be related to the addicts' own oral and dermal microflora. No correlation was observed between the chemical fillers and the bacteria recovered from the heroin.

Bacterial Infections↗
PubMed1983

In vivo evaluation of ocular inserts of hydrogel impregnated with antibiotics for trachoma therapy.

Sustained release of antibiotics from hydrogel matrices in the eye was studied for the purpose of developing a new method for trachoma therapy. Copolymers of N-vinylpyrrolidone were moulded into an ocular insert and impregnated with erythromycin or erythromycin estolate. The antibiotic-hydrogel inserts completely suppressed the chlamydia trachomatis infection in the owl monkey eyes. The drug elution rates were a little lower in vivo than in vitro. By comparison of the drug elution rate in the human eye with that in the owl monkey eye, similar therapeutic effect is expected in the treatment of human trachoma.

Animals↗