Antibiotic use and risk of ischemic stroke in the elderly

PURPOSE

To determine whether treating infections with antibiotics that have antichlamydial activity decreases the risk of ischemic stroke in the elderly.

SUBJECTS

We analyzed data from 199 553 subjects 65 years and older in a health care claims database who had continuous health and pharmacy coverage for at least 2 years between January 1, 1991, and September 30, 1997. Using proportional hazards models with time-dependent covariates for prior antibiotic prescription and adjusting for cardiovascular risk factors, we determined the associations between antibiotic use and first claim for ischemic stroke (n = 7,335) during the observation period.

RESULTS

Rates of stroke (per 1,000 person-years) were 6.64 for macrolides, 9.27 for quinolones, 7.49 for tetracyclines, 6.88 for penicillins, 7.97 for cephalosporins, 8.58 for trimethoprim-sulfamethoxazole, and 7.29 for subjects with no antibiotic claims. The adjusted hazard ratios (HR) were 0.94 (95% confidence interval [CI]: 0.87 to 1.01) for macrolides, 1.04 (95% CI: 0.91 to 1.18) for tetracyclines, 1.02 (95% CI: 0.95 to 1.08) for penicillins, and 1.00 (95% CI: 0.82 to 1.22) for trimethoprim-sulfamethoxazole. Subjects with claims for quinolone antibiotics (HR = 1.17; 95% CI: 1.09 to 1.26) and cephalosporins (HR = 1.09; 95% CI: 1.02 to 1.16) had a slightly higher risk of stroke.

CONCLUSION

Exposures to short courses of antibiotics are not associated with lower risk of ischemic stroke in patients aged 65 years and older.

An analysis of cardiac mortality in patients with new-onset end-stage renal disease in New York State

End-stage renal disease (ESRD) is associated with an overall one-year mortality of 23.5% in the US, of which cardiac causes constitute 50% of all deaths. Data on incident ESRD patients were obtained from the Health Care Financing Administration's 2728 and 2746 forms by special request from the ESRD Network of New York. 4,948 ESRD patients, who started dialysis in New York State from April 1, 1995, through April 1, 1996, were assessed to identify risk factors present at the initiation of dialysis that predict cardiac death. 899 deaths were registered during the 19-month-follow-up period, 50% of which were from cardiac causes. Using the Cox-proportional hazards model, the increasing age category, white race, the presence of one or more vascular co-morbid conditions, and the presence of diabetes and one or more cardiac co-morbid conditions significantly predicted cardiac death (p < 0.05). Diabetes increased the risk for cardiac death by 48% for those patients without any cardiac co-morbidities (RR = 1.48, p < 0.0082). In contrast with results observed in the general population, gender, serum albumin and body mass index were not significant predictors of cardiac death. In identifying risk factors present at the initiation ofdialysis that predict cardiac death, this study highlights factors that may be modified prior to dialysis initiation in order to improve life expectancy and mortality rates and decrease health care costs for the ESRD population.

Changes in liver function tests after laparoscopic cholecystectomy: not so rare, not always ominous

The incidental findings of increased alanine aminotransferase (ALT) and aspartate amino transferase (AST) after uneventful laparoscopic cholecystectomy (LC) prompted us to investigate the incidence and the clinical significance of this phenomenon. Changes in liver function test after LC (n = 55) were compared with those after OC (n = 16). Liver function tests were obtained preoperatively and postoperatively on days 1, 2, and 7. All of the patients fulfilled the selection criteria: normal preoperative liver function test and no endoscopic retrograde cholangiopancreatography, common bile duct exploration, or postoperative biliary complications (injury, infection, or obstruction). Converted cholecystectomies were also excluded. During LC, the intra-abdominal pressure was maintained within the conventional range of 14 to 15 mm Hg. ALT had doubled in the first 48 hours from the preoperative mean in 58.2 per cent in LC patients versus only 6.3 per cent in the OC group. AST doubled from the preoperative mean value in 38.2 per cent in the LC group versus only 6.3 per cent in the OC group. By the 7th postoperative day, the enzymes returned to the preoperative values in both the LC and the OC group. In many instances, a significant increase in ALT and AST blood levels occurred after uneventful LC. The phenomenon is transient as these enzymes returned to normal value within 7 days. These changes are clinically silent in patients with a normal liver function.

A health information network for managing innercity tuberculosis: bridging clinical care, public health, and home care

The purpose of this study was to use a health information network and innovative technology to coordinate tuberculosis care. An innercity medical center, a local health department, and a home care nurse service in northern Manhattan were used. The organizations were linked with computer networks. An automated decision support system with a natural language processor was used to detect tuberculosis cases and report them to the health department, and to select patients for respiratory isolation. Educational materials were placed on the World Wide Web and a Web-based kiosk. Home care nurses were outfitted with wireless pen-based computers, and data were relayed to the medical center. Automated tuberculosis case reporting resulted in time savings but not improved accuracy. Automated rules resulted in significant improvements in respiratory isolation. Kiosk educational materials were well-used. Wireless computing led to better access to information for both nurses and physicians, but not to reduction of workload. The key success element was recognition of critical priorities. It is concluded that innovative technology can facilitate the coordination of clinical care, public health, and home care.

Association between coronary heart disease and cancers of the breast, prostate, and colon

Coronary heart disease (CHD) and cancers of the breast, prostate, and colon are more common in industrialized countries than in the developing world, and to some degree, these conditions appear to share risk factors. To investigate whether there is an association between these cancers and a prior history of CHD, a hospital-based case-control study was conducted at Columbia-Presbyterian Medical Center in New York. The study was based on 252 breast cancer cases, 256 colorectal cancer cases, and 322 benign surgical controls, all of whom underwent biopsy or surgery between January 1989 and December 1992, and on 319 prostate cancer cases and 189 benign prostatic hypertrophy controls diagnosed between January 1984 and December 1986 (prior to widespread use of prostate-specific antigen screening). Medical records were reviewed on each, focusing on the preoperative anesthesia and surgical clearances. No association was found between a history of CHD and breast or colorectal cancer, but an elevated risk was found for prostate cancer (odds ratio, 2.00; 95% confidence interval, 1.18-3.39), using unconditional logistic regression with adjustment for appropriate confounders. No association was found between cigarette smoking and any of the three cancers. Aspirin use was protective for colorectal cancer (odds ratio, 0.35; 95% confidence interval, 0.17-0.73) but had no association with breast or prostate cancer. The study suggests that individuals with CHD are at elevated risk for prostate cancer but not breast or colorectal cancer. Etiological risk factors associated with CHD should be investigated with regard to prostate cancer. Patients with CHD may represent a high-risk group for prostate cancer and potential future targets for prostate cancer screening interventions.

Respiratory isolation of tuberculosis patients using clinical guidelines and an automated clinical decision support system

OBJECTIVE

To evaluate a clinical guideline and an automated computer protocol for detection and respiratory isolation of tuberculosis (TB) patients.

DESIGN

An automated computer protocol was tested on a retrospective cohort of adult culture-positive TB patients admitted from 1992 to 1993 to Columbia-Presbyterian Medical Center and evaluated prospectively from July 1995 until July 1996.

SETTING

A large teaching hospital in New York City.

PATIENTS

171 adult patients admitted from 1992 to 1993 and 43 patients admitted between July 1995 and July 1996.

INTERVENTIONS

The 1990 Centers for Disease Control and Prevention guidelines for preventing transmission of TB were adapted to formulate clinical guidelines to ensure early isolation of TB patients at Columbia-Presbyterian Medical Center.

RESULTS

Implementation of a clinical respiratory isolation protocol resulted in a significant improvement in TB patient isolation rates, from 45 (51%) of 88 in 1992 to 62 (75%) of 83 in 1993 (P<.001). In testing automated protocols, the theoretical improvement would have identified an additional 27 patients not isolated by clinicians, making the overall isolation rate 134 (78%) of 171. For the prospective evaluation, 30 (70%) of 43 TB patients were isolated by clinicians adhering to the clinical protocol. Four additional patients were identified by the automated TB protocol, making the combined isolation rate 34 (79%) of 43.

CONCLUSIONS

A clinical policy to isolate TB patients and suspected human immunodeficiency virus-infected patients with cough, fever, or radiographic abnormalities improved isolation of culture-documented TB patients from 1992 to 1993. Automated computer protocols were successful in identifying additional potentially infectious patients that clinicians failed to place on respiratory isolation. Clinical and automated protocols combined resulted in better isolation rates than a clinical protocol alone.

Automated tuberculosis detection

OBJECTIVE

To measure the accuracy of automated tuberculosis case detection.

SETTING

An inner-city medical center.

INTERVENTION

An electronic medical record and a clinical event monitor with a natural language processor were used to detect tuberculosis cases according to Centers for Disease Control criteria.

MEASUREMENT

Cases identified by the automated system were compared to the local health department's tuberculosis registry, and positive predictive value and sensitivity were calculated.

RESULTS

The best automated rule was based on tuberculosis cultures; it had a sensitivity of .89 (95% CI.75-.96) and a positive predictive value of .96 (.89-.99). All other rules had a positive predictive value less than .20. A rule based on chest radiographs had a sensitivity of .41 (.26-.57) and a positive predictive value of .03 (.02-.05), and rule the represented the overall Centers for Disease Control criteria had a sensitivity of .91 (.78-.97) and a positive predictive value of .15 (.12-.18). The culture-based rule was the most useful rule for automated case reporting to the health department, and the chest radiograph-based rule was the most useful rule for improving tuberculosis respiratory isolation compliance.

CONCLUSIONS

Automated tuberculosis case detection is feasible and useful, although the predictive value of most of the clinical rules was low. The usefulness of an individual rule depends on the context in which it is used. The major challenge facing automated detection is the availability and accuracy of electronic clinical data.

The emergence of drug-resistant tuberculosis in New York City

BACKGROUND

In the past decade the incidence of tuberculosis has increased nationwide and more than doubled in New York City, where there have been recent nosocomial outbreaks of multidrug-resistant tuberculosis.

METHODS

We collected information on every patient in New York City with a positive culture for Mycobacterium tuberculosis during April 1991. Drug-susceptibility testing was performed at the Centers for Disease Control and Prevention.

RESULTS

Of the 518 patients with positive cultures, 466 (90 percent) had isolates available for testing. Overall, 33 percent of these patients had isolates resistant to one or more antituberculosis drugs, 26 percent had isolates resistant to at least isoniazid, and 19 percent had isolates resistant to both isoniazid and rifampin. Of the 239 patients who had received antituberculosis therapy, 44 percent had isolates resistant to one or more drugs and 30 percent had isolates resistant to both isoniazid and rifampin. Among the patients who had never been treated, the proportion with resistance to one or more drugs increased from 10 percent in 1982 through 1984 to 23 percent in 1991 (P = 0.003). Patients who had never been treated and who were infected with the human immunodeficiency virus (HIV) or reported injection-drug use were more likely to have resistant isolates. Among patients with the acquired immunodeficiency syndrome, those with resistant isolates were more likely to die during follow-up through January 1992 (80 percent vs. 47 percent, P = 0.02). A history of antituberculosis therapy was the strongest predictor of the presence of resistant organisms (odds ratio, 2.7; P < 0.001).

CONCLUSIONS

There has been a marked increase in drug-resistant tuberculosis in New York City. Previously treated patients, those infected with HIV, and injection-drug users are at increased risk for drug resistance. Measures to control and prevent drug-resistant tuberculosis are urgently needed.

Ciprofloxacin-resistant methicillin-resistant Staphylococcus aureus in an acute-care hospital

Use of ciprofloxacin as an alternative to vancomycin for treatment of methicillin-resistant Staphylococcus aureus infection has been paralleled by the emergence of resistant strains. This phenomenon has also been noticed in our hospital. To confirm our observation, methicillin and ciprofloxacin susceptibilities were tested by disk diffusion and broth microdilution techniques. We studied 83 methicillin-resistant Staphylococcus aureus isolates obtained from various sources over a 4-month period. Ciprofloxacin resistance (MIC, greater than 2 micrograms/ml) was detected in 69 isolates (83%). Prior use of ciprofloxacin was reported for 24 of 69 patients with ciprofloxacin-resistant strains and 0 of 14 patients with ciprofloxacin-susceptible strains. The day of detection during the hospital stay and the location of the source patient were not significantly different between resistant and susceptible strains. Bacteriophage typing showed a higher occurrence of nontypeable strains among ciprofloxacin-resistant strains (54%). Review of our microbiology register showed a progressive increase in the rate of resistance to ciprofloxacin during the first year of use, with initial rates being about 10% and recent rates being higher than 80%. On the other hand, methicillin-susceptible S. aureus remained uniformly susceptible to ciprofloxacin (98.4%). We conclude that prior use of ciprofloxacin is an important factor for the selection of ciprofloxacin-resistant strains and that ciprofloxacin has limited usefulness against methicillin-resistant S. aureus.

Drug resistant tuberculosis among the homeless in New York City

The purpose of this study was to compare the frequency of infections due to drug resistant Mycobacterium tuberculosis between homeless and nonhomeless populations in an urban community hospital. We retrospectively examined the mycobacteriology registry of this hospital for culture-proven, susceptibility-tested cases of M tuberculosis disease from 1982 to 1987. Clinical records were analyzed for age, ethnicity, sex, residence, and history of alcoholism, intravenous drug abuse, acquired immunodeficiency syndrome, or previous tuberculosis. Of a total of 132 cases, 53 patients were homeless and 79 were not. Drug resistance was found in 21% of the isolates from homeless individuals and 8% of those from nonhomeless persons. Resistance to isoniazid was found in 19% and 1% (p less than 0.01), and for two or more drugs in 15% and 0% (p, 0.01), respectively. Forty-two patients were black, and among them, resistance to one or more drugs was 26.2%, versus 6.6% in nonblacks (p less than 0.01). Ten of 24 homeless blacks had resistant organisms, as opposed to 1 of 18 nonhomeless blacks (p less than 0.05). No other significant differences were noted for the other variables. To our knowledge, this is the first comparison of drug-resistant tuberculosis between homeless and nonhomeless patients using an internal control group. Forty percent of isolates from homeless blacks were resistant, two thirds to both isonlazid and rifampin. These findings support the use of an initial four-drug regimen to treat tuberculosis in this specific population.

High Staphylococcus aureus nasal carriage rate in patients with acquired immunodeficiency syndrome or AIDS-related complex

Staphylococcus aureus has been reported to cause a high number of infections and septicemias, often related to intravenous catheters, in patients with acquired immunodeficiency syndrome (AIDS). Our objective was to assess the frequency of S. aureus nasal carriage among patients with AIDS or AIDS-related complex (ARC). The nasal carriage rate of S. aureus was determined within 24 hours of admission in 64 consecutively hospitalized patients with AIDS or ARC. Intravenous drug abusers were excluded. A control group of 64 patients with other diseases was also tested. Of 64 patients with AIDS or ARC, 35 (55%) were nasal carriers of S. aureus, compared with 18 (28%) of 64 control patients. Recent hospitalization did not influence carriage rate, nor did the recent use of antibiotics or zidovudine. The significant S. aureus carriage rate in patients with AIDS or ARC may contribute to the high incidence of intravenous catheter-related S. aureus infections in this population.

House staff on-call scheduling: an intern's proposal

House staff scheduling is currently one of the most important issues in graduate medical education. Proposals for regulation arose as a result of mistakes made by exhausted interns, and they involve doctors, hospitals, the public, and authorities. The New York State Department of Health recommendations include restricting work to less than 80 hours per week and shifts to less than 24 consecutive hours.

Clinical features and management of severe dermatological reactions to drugs

Cutaneous adverse drug reactions are a frequent occurrence and have been reported in more than 2% of hospitalised patients. Among the most commonly involved drugs are sulphonamides, penicillins, anticonvulsants and non-steroidal anti-inflammatory drugs. Two groups of mechanisms are involved in the pathogenesis of drug reactions: immunological, with all 4 types of hypersensitivity reactions described; and non-immunological, accounting for at least 75% of all drug reactions. Besides minor skin reactions like urticaria, maculopapular rash, fixed eruptions or erythema nodosum, which are generally self-limited, severe life-threatening manifestations also occur. Erythema multiforme is secondary to drugs in half the cases; the minor form is characterised by typical target and iris lesions and is usually benign. However, a much more severe condition, erythema multiforme major or Stevens-Johnson syndrome, is associated with mucosal, ocular and visceral involvement, and carries a mortality of 5 to 15% if untreated. Toxic epidermal necrolysis, which could represent an even more dramatic form of the same disease, is characterised by severe widespread erythema, blisters and loss of skin in sheets, with denudation of more than 10% of the body surface area. This entity is frequently due to drugs. Mortality is 25 to 70%, and 90% of the survivors will have sequelae. Exfoliative dermatitis is an erythematous scaling disease often produced by drugs and carrying significant mortality. Photodermatitis may at times present with severe eczematous features. For clinical and epidemiological reasons it is important to try to identify the culprit drug following an approach based on previous experience with the drug, timing of events, patient reaction to dechallenge, patient reaction to rechallenge (if feasible), alternative aetiological candidates, and drug concentration or evidence of overdose. Management of severe skin reactions to drugs should require admission to a burn unit, where patients should be placed in warmed air-fluidised beds, receive excellent nursing care, analgesics and tranquillisers. Peeling necrotic epidermis should be removed and denuded dermis covered with biological grafts or synthetic dressings. Fluid balance must be adequately maintained; nutritional support and careful monitoring of early signs of skin infections is mandatory to ensure immediate antimicrobial treatment. Ocular care must be excellent to avoid serious sight-threatening sequelae. Steroids are presently not recommended. With these therapeutic modalities, morbidity and mortality can be markedly decreased.

Infections associated with Hickman catheters in patients with acquired immunodeficiency syndrome

PURPOSE

Hickman catheters are frequently used as convenient long-term venous access in patients with acquired immunodeficiency syndrome (AIDS). These patients seem to be at increased risk for bacterial infections of intravenous devices. The aim of our study was to determine the frequency of Hickman catheter infection in patients with AIDS as compared with that in other patients.

PATIENTS AND METHODS

We analyzed the records of 69 patients who underwent 71 consecutive Hickman catheter placements during a one-year study period.

RESULTS

Forty-six Hickman catheters were inserted in 44 patients with AIDS, and 25 Hickman catheters were placed in 25 other patients. There were 18 infections: 16 occurred in patients with AIDS, and two developed in the control group (p less than 0.05). The 16 infections in AIDS were as follows: five exit site, five septicemias, two tunnel, one septic phlebitis, and three probable Hickman catheter-related. Staphylococcus aureus was responsible for 14 cases (87%); Staphylococcus epidermidis was responsible for four cases (25%). Mean onset of infection was 32 days, but seven patients were diagnosed in the first eight days after Hickman catheter insertion. Fever occurred in all patients with early infection, leukopenia was present only in three; infusion of parenteral nutrition did not increase the risk. Two early infections were fatal. The rate of Hickman catheter infection in patients with AIDS was 0.47 per 100 catheter days, as compared with 0.09 in the control group.

CONCLUSION

Our findings underscore the need for using Hickman catheters only when absolutely indicated in patients with AIDS, since the risk of serious infectious complications appears to be high.

Fatal toxic epidermal necrolysis during prophylaxis with pyrimethamine and sulfadoxine in a human immunodeficiency virus-infected person

The combination of pyrimethamine and sulfadoxine (Fansidar) has been reported to cause severe skin reactions including erythema multiforme, Stevens-Johnson syndrome, and toxic epidermal necrolysis. Recently, this drug combination has been used for prophylaxis of Pneumocystis carinii pneumonia in patients with the acquired immunodeficiency syndrome. After two months of weekly prophylaxis with pyrimethamine and sulfadoxine, a 48-year-old homosexual man who was antibody positive for human immunodeficiency virus developed severe widespread erythema, blisters, and loss of skin in sheets, and subsequently died. To our knowledge, this is the first reported case of fatal toxic epidermal necrolysis occurring in a patient with acquired immunodeficiency syndrome-related complex. The lack of absolute safety of prophylaxis with pyrimethamine and sulfadoxine is emphasized in our case, and mandates cautious use and the consideration of less toxic prophylactic measures such as therapy with the recently introduced aerosolized pentamidine.