Search PubMed⌕ Search

Biomedical subjects

K K Lai

Publications and source records attributed to K K Lai.

At least 37 records · Page 2Linked to original sources
PubMed1998

Infections associated with implantable cardioverter defibrillators placed transvenously and via thoracotomies: epidemiology, infection control, and management.

In 1993, the incidence of infection associated with implantable cardioverter defibrillators (ICDs) excluding generator, lead, and patch placements was 16.7% at our institution. Eighty-eight percent of the ICD implantations were two-staged procedures: the cardiologists performed the electrophysiologic studies in their laboratories, and implantations were performed in the operating rooms a few hours to a few days later by cardiothoracic surgeons. In 1994, both the electrophysiologic studies and ICD implantations were performed in the operating rooms without waiting periods. From 1993 to 1995, the proportion of ICDs placed transvenously increased from 56% to 100%, whereas the proportion of two-staged ICD placements decreased from 88% to zero. From 1992 to 1993 the infection rate decreased concomitantly from 16.7% to zero. From 1992 through 1995, the infection rate for implantable ICDs alone was 4.8%, and the overall infection rate for implantable ICDs (including generator, lead, and patch placements) was 6.9%, comparable to the rate reported in the literature (2.2% to 7.2%). The elimination of the two-stage procedure and the increased proportion of transvenously placed ICDs has contributed to the decrease in infection rate.

Catheterization↗
PubMed1998

Failure to eradicate vancomycin-resistant enterococci in a university hospital and the cost of barrier precautions.

OBJECTIVE: To describe the effect of infection control interventions on the incidence of vancomycin-resistant enterococci (VRE), the utility of pharyngeal cultures for surveillance for VRE colonization, and the cost of barrier precautions. DESIGN: Evaluation of the occurrence of VRE infection or colonization, rates of vancomycin use, results of surveillance cultures before and after interventions, and the cost of increased barrier precautions. SETTING: University of Massachusetts Medical Center, a 347-bed tertiary-care teaching hospital with eight intensive-care units, one burn unit, and one bone marrow transplant unit. PARTICIPANTS: Patients in the intensive-care units and staff who were involved with patients colonized or infected with VRE. METHODS: Infection control interventions included placement of patients with VRE in private rooms, strict contact isolation, cohorting of patient and nursing staff, prohibiting of equipment sharing, and monitoring of compliance with the vancomycin restriction policy, with hand washing, and of the adequacy of environmental cleaning. Both rectal and pharyngeal cultures were obtained from patients at the beginning of the outbreak, and the utility of pharyngeal cultures was evaluated. The cost of barrier precautions was estimated by comparing the cost of glove and gown use before and after the outbreak began. RESULTS: The interventions decreased the number of new cases of VRE, but total eradication of VRE was not achieved. Compliance with the room-cleaning protocol was 91% (141/155 observations). Hand washing following interaction with patients who were not in isolation was 51%, vs 100% for patients in isolation. Overall, handwashing compliance was 71% (319/449): 56% (130/231) for physicians and 86% (187/218) for nurses (P<.0001). The mean number of doses of vancomycin dispensed per 1,000 patient days decreased from 145 to 114 per 1,000 patient days (P<.001). Compliance with vancomycin-use guidelines was 85%. Forty-six (77%) of 60 surveillance rectal swabs yielded enterococci, as compared to only 4 (11%) of 36 pharyngeal cultures (P<.0001). Expenses on glove and gowns alone increased by over $11,000 per year since the epidemic began. CONCLUSIONS: Implementation of the various infection control measures did not eradicate VRE cases from the hospital. Rectal cultures were more useful than pharyngeal cultures for surveillance of VRE. Controlling VRE epidemics can be costly.

Cross Infection↗
PubMed1997

Itraconazole maintenance treatment for histoplasmosis in AIDS: a prospective, multicenter trial.

PURPOSE: To study the efficacy and safety of maintenance treatment with itraconazole for disseminated histoplasmosis in patients with AIDS. PATIENTS AND METHODS: This was a prospective, multicenter, open-label study conducted at university-based hospitals participating in the AIDS Clinical Trial Group (ACTG). Forty-six AIDS patients with mild to moderate disseminated histoplasmosis who had successfully completed 12 weeks of induction treatment with itraconazole were treated with itraconazole, 200 mg once daily (42 patients) or 400 mg once daily (4 patients). Patients were followed at monthly intervals with clinical and laboratory assessment for relapse or toxicity. Primary outcome measures were relapse of histoplasmosis and survival. Secondary outcome measures included drug-limiting toxicity and changes in serum and urine Histoplasma polysaccharide antigen (HPA) levels. RESULTS: Two patients relapsed during a median follow-up period of 87 weeks. The 1-year relapse-free rate was estimated to be 95.3% (95% CI, 85.3%-99.7%). One relapse may have been related to poor adherence to treatment and the second to concurrent administration of rifampin. From the start of maintenance treatment, the estimated 1-year survival rate was 73.0% (95% CI, 67.5%-77.9%). Five patients discontinued treatment because of suspected drug toxicity, three of whom had possible or probable hepatotoxicity. Median serum and urine HPA levels declined significantly during treatment. The only patient in whom antigen levels rose >2 U developed clinical relapse 1 week later; antigen levels were unavailable in the other relapsing patient. CONCLUSIONS: Itraconazole, 200 mg daily, is effective in preventing relapse of disseminated histoplasmosis in patients with AIDS. It is generally well tolerated, but clinicians should be alert for drug interactions and possible hepatotoxicity.

AIDS-Related Opportunistic Infections↗
PubMed1997

Treatment of histoplasmosis with fluconazole in patients with acquired immunodeficiency syndrome. National Institute of Allergy and Infectious Diseases Acquired Immunodeficiency Syndrome Clinical Trials Group and Mycoses Study Group.

PURPOSE: This study assesses the efficacy and safety of fluconazole therapy in patients with acquired immunodeficiency syndrome (AIDS) and mild to moderately severe manifestations of disseminated histoplasmosis. PATIENTS AND METHODS: This was a multicenter, open-label, nonrandomized prospective trial. All patients had AIDS and disseminated histoplasmosis. Patients were treated with 1,200 mg of fluconazole given by mouth once on the first day, then 600 mg once daily for 8 weeks, and those patients who improved clinically were then assigned fluconazole maintenance therapy 200 mg once daily for at least 1 year. Interim analysis revealed a high failure rate (10 of 20, 50%), causing revision of the protocol to increase the fluconazole dose to 1,600 mg given once on the first day, then 800 mg once daily, and the duration to 12 weeks for induction therapy and then 400 mg daily for 1 year for maintenance therapy. MEASUREMENTS AND MAIN RESULTS: Thirty-six of 49 patients (74%; 95% confidence interval [CI]: 59% to 85%) with mild to moderately severe clinical manifestations who entered into the revised study responded to 800 mg of fluconazole daily for 12 weeks as induction therapy. Of the seven patients who failed induction therapy because of progression of histoplasmosis, one died of the infection. Of 36 patients who entered into the maintenance phase of the study receiving 400 mg of fluconazole daily for 1 year, 11 (30.5%) relapsed, including one who died (2.8%). Two of the 49 patients (4.1%) were removed because of grade 4 adverse events, alkaline phosphatase elevation for one and aspartate aminotransferase elevation in the other. The relapse-free rate at 1 year was 53% (95% CI: 32% to 89%), prompting closure of the study. CONCLUSIONS: Fluconazole 800 mg daily is a safe and moderately effective induction therapy for mild or moderately severe disseminated histoplasmosis in patients with AIDS. On the basis of historic comparison, fluconazole 400 mg daily is less effective than itraconazole 200 to 400 mg daily or amphotericin B 50 mg given weekly as maintenance therapy to prevent relapse.

AIDS-Related Opportunistic Infections↗
PubMed1997

Clostridium difficile-associated diarrhea: epidemiology, risk factors, and infection control.

OBJECTIVES: To evaluate the effectiveness of specific infection control measures on the incidence of Clostridium difficile-associated diarrhea (CDAD) and to identify risk factors for its development. SETTING: 370-bed, tertiary-care teaching hospital with approximately 12,000 to 15,000 admissions per year. METHODS: Several infection control measures were implemented in 1991 and 1992, and the attack rates of CDAD were calculated quarterly. Antibiotic use for 1988 through 1993 was analyzed. A case-control study was conducted from January 1992 to December 1992 to identify risk factors for acquisition of CDAD. RESULTS: From 1989 to 1992, the attack rate of CDAD increased from 0.49% to 2.25%. An increase in antibiotic use preceded the rise in the incidence of CDAD in 1991. Despite implementation of various infection control measures, the attack rate decreased to 1.32% in 1993, but did not return to baseline. Ninety-two cases and 78 controls (patients with diarrhea but with negative toxin assay) were studied. By univariate analysis, history of prior respiratory tract infections (odds ratio [OR], 3.6; 95% confidence interval [CI95], 1.2-10.4), the number of antibiotics, and the duration of exposure to second-generation cephalosporins (OR, 3.55; CI95, 1.47-9.41) and to ciprofloxacin (OR, 7.27; CI95, 1.13-166.0) were related significantly to the development of CDAD. By stepwise logistic regression analysis, only exposure to antibiotics and prior respiratory tract infections (P = .0001 and .0203, respectively) were found to be significant. CONCLUSION: Antibiotic pressure might have contributed to failure of infection control measures to reduce the incidence of CDAD to baseline.

Analysis of Variance↗
PubMed1997

The Model Physician-Assisted Suicide Act and the jurisprudence of death.

A Model Statute to Authorize and Regulate Physician-Assisted Suicide was published in 1996. This article describes the Act and some of its background and effects in detail, showing that it goes further than at first appears. Specifically, the article discusses the background and basic effect of the Act, the principal provisions of the Act and their effects, the morality and jurisprudence of the Act, the argument from autonomy, and the argument from utility. The authors conclude that by ignoring the moral traditions of Western culture, and focusing only on the ethics and anthropology of autonomy and utility, the drafters of the Act justify the dehumanization of the very people the Act is supposed to benefit.

Ethical Theory↗
PubMed1997

The epidemiology of fecal carriage of vancomycin-resistant enterococci.

An outbreak of vancomycin-resistant enterococci (VRE) began at the University of Massachusetts Medical Center in May 1993. As of September 1995, we had a total of 253 patients infected or colonized with VRE, with consequent increasing demand for private rooms. We analyzed results of surveillance cultures for VRE of 49 patients known to be colonized or infected with VRE. Of these, 34 (70%) were classified as persistent carriers, defined as patients with at least three consecutively positive cultures from any site taken over at least a 2-week period. The length of carriage varied from 19 to 303 days (median, 41 days); 11 patients were converters, defined as patients with three consecutive negative cultures from all previously colonized sites taken over a 3-week period. These patients were free of VRE for 39 to 421 days (median, 142 days). Four were recolonizers after they were documented to be clear of VRE for 33 to 106 days. VRE carriage tends to be prolonged, and hospitalization of patients with VRE will require continued isolation and contact precautions for control of transmission.

Carrier State↗
PubMed1996

Knowledge of the transmission of tuberculosis and infection control measures for tuberculosis among healthcare workers.

Two hundred seventy-five of 325 (85%) healthcare workers (HCWs) completed a questionnaire testing their knowledge of transmission of tuberculosis (TB) and infection control measures for TB. Of the 75 HCWs with no patient contact, 49 (65%) felt that masks should be worn, and 40 (53%) would use gowns. In contrast, 175 (88%) of 200 HCWs having contact with patients thought masks should be worn, and 70 (35%) would use gowns (P = .0001 and .0085, respectively). Only 87% of HCWs with patient contact felt that respiratory precautions should be instituted for TB patients. The results of our survey showed that HCWs should be reeducated about TB.

Centers for Disease Control and Prevention, U.S.↗
PubMed1993

Factors affecting peak expiratory flow variability and bronchial reactivity in a random population sample.

BACKGROUND: Bronchial reactivity measurements are widely used in epidemiological studies to provide an objective marker of asthma. There are, however, several potential advantages of measuring peak expiratory flow (PEF) variability instead, particularly in large studies. PEF variability and bronchial reactivity were compared in a population sample to assess the relationships of the two measurements to factors known to be associated with airways disease, and to compare their response rates. METHODS: Subjects aged 18-65 were randomly selected from the electoral register of an administrative area in eastern England and randomised to attend either for a bronchial challenge test measuring the provocative dose of methacholine producing a 20% fall in FEV1 (PD20), or to measure PEF at two hourly intervals during waking hours for one week. Skin tests with common allergens were performed and a smoking history obtained. PEF variability was expressed as the amplitude % mean (highest - lowest x 100/mean). RESULTS: A total of 273 subjects (69%) collected a PEF meter but a completed record sheet was returned by only 247 (62%); this was still significantly more than the 202 subjects (54%) who attended for and successfully completed a challenge test. Amplitude % mean was higher in women than in men (9.7% v 8.5%). In multiple regression analysis amplitude % mean increased significantly with age, mean skin weal diameter, and with current smoking. The odds of having a PD20 below 24.5 mumol increased with mean skin weal diameter and were greater in current smokers. Neither age nor sex had a significant effect on bronchial reactivity but there were significant interactions between age and the effects of both smoking and atopy. CONCLUSIONS: The higher response rate associated with the use of PEF variability measurement, and the association with factors implicated in the pathogenesis of airways disease, suggest that PEF variability would be a useful measurement to employ in epidemiological studies.

Adolescent↗
PubMed1991

Direct evidence of the metal-free nature of sirohydrochlorin in desulfoviridin.

We have obtained direct evidence that the majority of the sirohydrochlorin chromophore in the dissimilatory sulfite reductase desulfoviridin from Desulfovibrio gigas, is not associated with any metal. The evidence comes from resonance Raman measurements of native and deuterated samples of desulfoviridin. The breathing mode v4 (or v4*) at 1336 cm-1 in the native enzyme is downshifted to 1326 cm-1 upon deuteration. This mode is not sensitive to deuteration if a metal is present at the center of the chromophore inside protein or in solution. The results also establish the existence of exchangeable core hydrogen(s) at the pyrrolic nitrogen(s).

Desulfovibrio↗