Search PubMed⌕ Search

Biomedical subjects

K K Lai

Publications and source records attributed to K K Lai.

At least 19 recordsLinked to original sources
PubMed1999

Terrestrial gamma ray dose rates of Brunei Darussalam.

GPS-indexed in-situ and car-borne survey of terrestrial gamma-ray dose rates were carried out in Brunei and adjacent areas using two portable NaI(Tl) counters. The mean and population weighted average dose rates for Brunei are 34 and 33 nGy/h, respectively. The car-borne data and the in-situ data when spectral analysed separately, were found to show fractal behaviour with D of 1.7 and 1.8, respectively. A contour map of the dose rates was also produced.

Air Pollutants, Radioactive↗
PubMed1999

I-131 orthoiodohippurate assessment of renal function after heart transplantation.

PURPOSE: The authors studied the relation between cardiac output (CO) and effective renal plasma flow (ERPF) and compared values from control patients with various cardiac problems with those in a group of study patients who had undergone heart transplantation. METHODS: The experimental group was divided into three subgroups according to the interval between the time of surgery and the time of the CO-ERPF studies. Group 1 consisted of patients studied fewer than 10 days after surgery; group 2 consisted of patients studied 10 to 20 days after operation; and group 3 consisted of patients studied more than 20 days after operation. Effective renal plasma flow was determined by the single-injection, single plasma sample method, where 50 microCi I-131 orthoiodohippurate was injected intravenously in a single dose and plasma concentrations of radioactivity were determined. The quotient of injected dose radioactivity divided by plasma radioactivity is highly predictive of global ERPF. Cardiac output was measured by thermodilution. RESULTS: In the control group, a positive linear correlation was found between CO and ERPF; however, the CO:ERPF ratio was elevated, and after heart transplantation, a lag time was observed for as long as 3 weeks in some patients before CO:ERPF ratios returned to control group levels. The regression equation and standard error for the control group was CO = 1.85 + 0.0065 ERPF (+/-0.62) l/min versus 1.433 + 0.0068 ERPF (+/-0.64) l/min for group 3. The correlation coefficients comparing CO with ERPF were r = 0.88, 0.23, 0.51, and 0.85, for the control group and groups 1, 2, and 3, respectively. CONCLUSION: A localized release of catecholamines from the adrenal gland is proposed to cause ERPF damping after abrupt increases in CO.

Adrenal Glands↗
PubMed1998

The coding audit.

Explore the source record for details and available documents.

Centers for Medicare and Medicaid Services, U.S.↗
PubMed1998

Safety of prolonging peripheral cannula and i.v. tubing use from 72 hours to 96 hours.

OBJECTIVE: To compare the rates of phlebitis of peripheral intravenous lines left in place for 72 hours versus rates of those left in place 96 hours. DESIGN: A prospective, nonrandomized study. SETTING: A university teaching hospital with 375 beds. PATIENTS: Consecutive adult patients who received peripheral intravenous lines and were admitted to the wards. MEASUREMENTS: The phlebitis rates were monitored by the i.v. Team for 1 month according to a predetermined definition for phlebitis: palpable cord or at least two of the following: tenderness, warmth, erythema, and induration. RESULTS: A total of 2503 peripheral lines were evaluable. The overall phlebitis rate was 6.8%. The phlebitis rates for lines left in for 72 and 96 hours were not significantly different (3.3% vs 2.6%, p = 1.000) by Fisher's Exact Test and survival analysis. It was estimated that in 1 month approximately 300 intravenous lines potentially could be prolonged beyond 72 hours; 215 lines were changed at 72 hours despite no signs of inflammation, 61 lines were kept till 96 hours, and 19 lines were kept beyond 96 hours. CONCLUSIONS: Phlebitis rate for our peripheral intravenous catheters at 96 hours was not significantly different from that at 72 hours. If intravenous cannulas and lines were prolonged to 96 hours, a potential cost saving of $61,200 per year could be realized.

Adult↗
PubMed1998

Long-term laboratory contamination by Mycobacterium abscessus resulting in two pseudo-outbreaks: recognition with use of random amplified polymorphic DNA (RAPD) polymerase chain reaction.

Beginning in 1993, an increase in clinical isolates of Mycobacterium abscessus was observed in a single hospital microbiology laboratory. This involved a cluster of four patients in June 1993 and five patients and a quality-control culture of distilled water in May 1994. Twenty-three M. abscessus isolates recovered between 1991 and 1996 were compared by random amplified polymorphic DNA polymerase chain reaction (RAPD-PCR). Sixteen of 21 clinical isolates recovered over a 6-year period and the distilled water isolate had identical RAPD-PCR patterns consistent with a single strain or clone. Only six of 15 patients had findings suggestive of clinical disease. Since the use of in-house-prepared distilled water was discontinued, no further laboratory contamination of clinical specimens has been observed. Molecular typing was the key to defining distilled water as the source of this pseudo-outbreak. Recognition of such outbreaks is important for prevention of unnecessary therapeutic and diagnostic interventions.

Adolescent↗
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.↗