PubMed HealthSearch

Biomedical subjects

A W Karchmer

Publications and source records attributed to A W Karchmer.

At least 19 recordsLinked to original sources

Pseudallescheria boydii endocarditis of the pulmonic valve in a liver transplant recipient.

We describe a case of Pseudallescheria boydii endocarditis involving the pulmonic valve in an orthotopic liver transplant recipient. The patient required transplantation because of hepatic failure secondary to chronic active hepatitis B. His postoperative course was complicated by surgery for gastric and duodenal ulcers, persistent fever, and, ultimately, sepsis leading to oliguric renal failure. Two days before death, the patient experienced complete heart block, and an echocardiogram revealed pulmonic valve thickening and an endocardial mass along the left side of the septum. At autopsy the patient was found to have a vegetation on the pulmonic valve and a septal abscess. There were multiple fungal emboli found throughout other organs, and P. boydii was obtained on culture. This unique association between pulmonic valve endocarditis and myocardial septal abscess is discussed. In addition, review of the five previous cases of P. boydii endocarditis reveals that this rare infection is associated with immunosuppression and prosthetic devices.

Endocarditis

Prophylaxis against wound infection following herniorrhaphy or breast surgery.

The effect of perioperative antibiotic prophylaxis on definite wound infections was assessed for 3202 herniorrhaphies or selected breast surgery procedures. Patients were identified preoperatively and monitored for greater than or equal to 4 weeks. Thirty-four percent of patients (1077/3202) received prophylaxis at the discretion of the surgeon; 86 definite wound infections (2.7%) were identified. Prophylaxis recipients were at higher risk for infection, with a higher proportion of mastectomies, longer procedures, and other factors. Patients who received prophylaxis experienced 41% fewer definite wound infections (odds ratio [OR], 0.59; 95% confidence interval [CI], 0.35-0.99; P = .04) and 65% fewer definite wound infections requiring parenteral antibiotic therapy (OR, 0.35; 95% CI, 0.15-0.88; P = .02) after adjustment for duration of surgery and type of procedure. Additional adjustment for age, body mass index, the presence of drains, diabetes, and exposure to corticosteroids did not change the magnitude of this effect meaningfully. The effect of prophylaxis was similar for all procedures studied. In the absence of formal guidelines, surgeons at these institutions administered prophylaxis preferentially to patients at highest risk.

Anti-Bacterial Agents

Misplaced caval filter and subsequent pericardial tamponade.

Use of the Greenfield filter for partial caval interruption is generally accepted as the most reliable mechanical method of pulmonary embolus prophylaxis. However, there have been reports of a variety of (usually nonfatal) complications. We report here the near-fatal complication of acute pericardial tamponade after misplacement of a Greenfield filter. Because of the filter's unusual location, retrieval required cardiopulmonary bypass, profound hyperthermia, and circulatory arrest.

Adult

Prosthetic valve endocarditis: a continuing challenge for infection control.

Conventional medical thought accepts the risks of nosocomial prosthetic valve endocarditis (PVE) to be between 0.7 and 1.4%, the incidence within several months after surgery. More careful actuarial analysis of recent series suggests the risk of nosocomial PVE is 1.4-3.0%, with cases occurring throughout the year after surgery. Methicillin-resistant coagulase-negative staphylococci are the predominant cause of nosocomial PVE and account for 60% of cases. Intraoperative contamination by Staphylococcus epidermidis of nosocomial origin has led to small epidemics of PVE. Aside from the fundamental elements of aseptic surgical technique, studies have failed to identify elements of intraoperative or postoperative care that might be modified to reduce the incidence of sporadic cases of nosocomial PVE. Prophylactic antibiotics have become an essential element in the effort to prevent PVE. Some recent studies have advocated using cefamandole or cefuroxime for prophylaxis; however, other studies have failed to find these agents more effective than cefazolin. The use of vancomycin for prophylaxis requires additional study. Intensive studies are needed to define elements of perioperative and postoperative care that can be modified to reduce the frequency of nosocomial PVE.

Anti-Bacterial Agents

Perioperative antibiotic prophylaxis for herniorrhaphy and breast surgery.

We assessed the efficacy of perioperative antibiotic prophylaxis for surgery in a randomized, double-blind trial of 1218 patients undergoing herniorrhaphy or surgery involving the breast, including excision of a breast mass, mastectomy, reduction mammoplasty, and axillary-node dissection. The prophylactic regimen was a single dose of cefonicid (1 g intravenously) administered approximately half an hour before surgery. The patients were followed up for four to six weeks after surgery. Blinding was maintained until the last patient completed the follow-up and all diagnoses of infection had been made. The patients who received prophylaxis had 48 percent fewer probable or definite infections than those who did not (Mantel-Haenszel risk ratio, 0.52; 95 percent confidence interval, 0.32 to 0.84; P = 0.01). For patients undergoing a procedure involving the breast, infection occurred in 6.6 percent of the cefonicid recipients (20 of 303) and 12.2 percent of the placebo recipients (37 of 303); for those undergoing herniorrhaphy, infection occurred in 2.3 percent of the cefonicid recipients (7 of 301) and 4.2 percent of the placebo recipients (13 of 311). There were comparable reductions in the numbers of definite wound infections (Mantel-Haenszel risk ratio, 0.49), wounds that drained pus (risk ratio, 0.43), Staphylococcus aureus wound isolates (risk ratio, 0.49), and urinary tract infections (risk ratio, 0.40). There were also comparable reductions in the need for postoperative antibiotic therapy, non-routine visits to a physician for problems involving wound healing, incision and drainage procedures, and readmission because of problems with wound healing. We conclude that perioperative antibiotic prophylaxis with cefonicid is useful for herniorrhaphy and certain types of breast surgery.

Bacterial Infections

Pseudallescheria boydii infection of the central nervous system.

Pseudallescheria boydii is a rare cause of central nervous system infection characteristically presenting as a neutrophilic meningitis or multiple brain abscesses. Factors predisposing to central nervous system infection with this fungus include immunosuppression and near drowning. The organism is infrequently cultured from fluid obtained by lumbar puncture, delaying clinical recognition and appropriate antifungal therapy. All untreated patients with P boydii infection of the central nervous system died. We describe a patient who developed a persistent neutrophilic meningitis with focal neurologic deficits due to P boydii 6 months after a freshwater aspiration pneumonia. We also review the characteristic clinical and pathologic features of previously reported cases and emphasize the importance of early detection and treatment in the management of this frequently intractable disease.

Adult

Antibiotic therapy of nonenterococcal streptococcal and staphylococcal endocarditis: current regimens and some future considerations.

Regimens for endocarditis caused by these bacteria are generally based on high dosage of a beta-lactam antibiotic, penicillin in the case of streptococci and a penicillinase-resistant penicillin for Staphylococcus aureus, with vancomycin substituted for beta-lactam resistant staphylococci, including coagulase-negative staphylococci. The addition of other antimicrobial agents, such as aminoglycosides (or, in the case of staphylococci, sodium fusidate or rifampicin) may increase bactericidal efficiency, or allow shorter courses, but problems of toxicity or emergence of resistance may occur. Optimal regimens are discussed, and newer agents of possible usefulness are reviewed.

Anti-Bacterial Agents

Synergistic activity between vancomycin or teicoplanin and gentamicin or tobramycin against pathogenic diphtheroids.

The in vitro activities of vancomycin and teicoplanin alone and in combination with gentamicin or tobramycin were studied by time-kill techniques with 11 strains of pathogenic diphtheroids (Corynebacterium group JK). The activities of vancomycin and teicoplanin were similar (MIC for 90% of strains tested [MIC90], 1 microgram/ml), as were those of gentamicin and tobramycin (the MIC90 was 1 microgram/ml for five aminoglycoside-susceptible strains, and the MIC90 was greater than 1,024 micrograms/ml for six aminoglycoside-resistant strains). No consistent synergistic killing could be demonstrated by the combination of glycopeptide and aminoglycoside antibiotics at arbitrarily chosen concentrations within the range of clinically achievable levels. However, by careful adjustment of both vancomycin and gentamicin concentrations within a narrow range below the MIC of each antibiotic, synergistic killing could be seen with an aminoglycoside-susceptible strain but not with an aminoglycoside-resistant strain. Synergism between glycopeptide and aminoglycoside antibiotics occurs with some diphtheroid organisms, but it may not be clinically relevant.

Corynebacterium

Native valve endocarditis due to coagulase-negative staphylococci. Clinical and microbiologic features.

Twenty-one patients with native valve endocarditis caused by coagulase-negative staphylococci were studied; 14 had pre-existing valvular or congenital heart disease. Although commonly subacute in presentation, complications of endocarditis were frequent: arterial emboli in five patients, new electrocardiographic conduction system abnormalities in nine, congestive heart failure in eight, annular or myocardial abscesses in five, and disruption of valve leaflets in three. Cures were achieved in 10 of 12 patients treated medically and seven of nine treated surgically. In microbiologic studies of 16 coagulase-negative staphylococci from patients with endocarditis, only eight were identified as Staphylococcus epidermidis. All isolates were susceptible to vancomycin. Antibiotic resistance (methicillin, four isolates; gentamicin, two isolates; rifampin, one isolate) was usually associated with nosocomial acquisition of endocarditis. Rather than representing contamination, coagulase-negative staphylococci in blood cultures may indicate life-threatening endocarditis. However, with careful attention to the selection of antibiotics for therapy and to the occurrence of heart failure due to intracardiac complications, treatment of this form of endocarditis is frequently successful. Organisms must always be tested for cryptic resistance to beta-lactam antibiotics. Valve replacement may be required frequently.

Anti-Bacterial Agents

Ampicillin versus cefamandole as initial therapy for community-acquired pneumonia.

One hundred seven patients with community-acquired pneumonia thought to be of bacterial etiology by the admitting physician but whose initial sputum Gram stain was inadequate to direct specific therapy were randomized to receive either intravenous ampicillin or cefamandole as empiric therapy. Patients were excluded if the initial sputum Gram stain was highly suggestive of infection with Streptococcus pneumoniae, Staphylococcus aureus, or an enteric gram-negative bacillus. The two study groups had comparable demographic and presenting clinical features. The mean age of the patients evaluable for determination of clinical efficacy was 69 years, and greater than 75% had at least one serious underlying medical disorder. In the 90 evaluable patients, there were 11 therapeutic failures (12%), including 5 deaths (5%). Cefamandole, a broad-spectrum antibiotic, was not more efficacious than ampicillin in producing a satisfactory clinical response or in shortening the duration of parenteral therapy. Patients received an average of only 4 days of intravenous antibiotics before changeover to oral therapy and were hospitalized for a mean of 7 days. No patient experienced a relapse of pneumonia following successful completion of parenteral drug therapy. We conclude that cefamandole is not a more effective agent than ampicillin for empiric therapy of community-acquired bacterial pneumonia of uncertain etiology.

Administration, Oral