HEALTH CARE PROVIDERS' HANDS AS VECTORS OF VRE
Study confirms transfer can occur in patient's room.
In the delivery of routine bedside care, the gloved hands of health care providers contaminated clean areas of the rooms of patients colonized by vancomycin-resistant enterococci (VRE) 10.6% of the time, according to research conducted to assess the long-held belief that providers contribute to the spread of the bacteria and of other nosocomial infections.
Data were collected over eight months from both the rooms of patients colonized with gastrointestinal VRE (as confirmed by positive rectal culture) in a medical ICU and from the hands of health care providers. Researchers began by taking cultures of 12 selected areas on patients' bodies and 34 selected areas in their rooms prior to any entry by a health care provider. Once bedside care had been rendered, cultures of those areas were again taken, with the exception of a body area that had not been touched. Levels of mobility and consciousness among the patients were monitored to ensure that the finding of "false" contamination, that attributable to a patient, did not occur. As providers entered and exited the patients' rooms, cultures of their hands were taken (if gloves were used, cultures of both gloves and hands were taken upon exit). While in a patient's room, the health care provider was observed and his contact with both the areas of the patient's body and the environmental areas documented in sequence.
The study evaluated 22 VRE-positive patients and their rooms, and culturing was conducted 27 times. As expected, initial cultures revealed that patients' body areas were more heavily contaminated with VRE than were environmental ones. The transfer of VRE was considered positive if the VRE-negative hand of a health care provider had touched a VRE-positive area, then touched an initially VRE-negative area (the "destination site") that was subsequently found to be VRE-positive. The researchers calculated that there were 151 opportunities for health care providers to transfer bacterial microbes via the hands and that of those, 16 resulted in transferal of VRE (a 10.6% incidence). All instances of such transfer originated in the gloved hands of health care providers, and 13 of the 16 transferals occurred in rooms in which the patient was unconscious and therefore unable to cause contamination. In the majority of instances (12), the origin of VRE was an area of the patient's body, the antecubital area identified as being the most "efficient" in the transferal of the bacteria. The blood pressure cuff also was cited as an "efficient" medium of such transferal.
The results of the study suggest that, in addition to more frequent handwashing among health care providers, environmental cleaning, and frequent changes of gloves, other infection-control measures may be necessary to control the spread of VRE, such as the decontamination of patients (by bathing them in an antimicrobial solution, for example).-AK
Duckro A, et al. Arch Intern Med 2005; 165(3):302-7.
DETECTION OF LOWER ARTERIAL EXTREMITY DISEASE BY PULSE OXIMETRY
Easily employed, uninvasive screening tool for patients with diabetes.
Patients with type 2 diabetes who don't have symptoms of lower extremity arterial disease (LEAD) can benefit from pulse oximetry as a tool used to screen for it, according to a recent study.
Fifty-seven patients, all with type 2 diabetes and with no symptoms of LEAD, were enrolled in the study. Each participant underwent three diagnostic procedures during a routine office visit--pulse oximetry, assessment of the ankle-brachial index (ABI), and Doppler wave examination. Pulse oximetry measurements were obtained at the index finger and the big toe--the latter one taken both with the patient lying flat and when the toe was elevated 12 inches. To calculate the ABI, the patient's ankle pressure, as determined with a sphygmomanometer, was divided by the systolic blood pressure taken at the arm. A Doppler test, the standard used for comparison with pulse oximetry and ABI results, was performed on the legs and independently analyzed for the presence of the monophasic waveforms indicative of LEAD.
Pulse oximetry and ABI results were analyzed independently and in combination to evaluate the degrees of sensitivity (the likelihood of a positive result in patients with LEAD) and of specificity (the likelihood of a negative result in patients without LEAD). If the arterial oxygen saturation (SaO2) was found to have decreased by 2% or more between the index finger reading and the toe reading, or between the toe reading when the patient was lying flat and when the toe was elevated, the test was considered positive. In the ABI, the test was considered positive if the measurement was lower than 0.9. When both tests were performed, a positive result on either was considered indicative of LEAD.
By Doppler testing, 31% of the patients showed evidence of LEAD. Using pulse oximetry, a sensitivity level of 77% and a specificity level of 97% were achieved; with the ABI, the sensitivity level was 63% and the specificity level 97%. When the tests were used in combination, the sensitivity was 86% and the specificity 92%. Although the sample size of the study was small, the results suggest that pulse oximetry may be used to screen for LEAD, and that the combination of ABI and pulse oximetry yields an even more reliable diagnosis, compared with either method alone.-AK
Parameswaran G, et al. Arch Intern Med 2005;165(4):442-6.
CORD BLOOD TRANSPLANTATION
May be option in treatment of acute leukemia.
Two new studies report that cord blood transplantation may serve as a suitable alternative to conventional human leukocyte antigen (HLA)-matched bone marrow transplantation in adult patients with leukemia who do not have an HLA-matched bone marrow donor. The individual studies were conducted by Hopital Saint-Louis and Hopital Saint-Antoine, in Paris, and by the Case Comprehensive Cancer Center and University Hospitals of Cleveland Ireland Cancer Center in Cleveland, Ohio.
The study conducted by the two Parisian hospitals extended from 1998 to 2002 and involved 682 adults with acute leukemia who received hematopoietic stem-cell transplants from unrelated donors. Of those, 98 received cord blood and 584 received bone marrow. The marrow transplant recipients were HLA matched, but 94% of the cord blood graft recipients were not.
The Cleveland group consisted of 150 patients who had been diagnosed with acute leukemia and had undergone transplantation of hematopoietic stem cells, from unrelated donors, that was mismatched for either one antigen (34 patients) or two antigens (116 patients). The 450 bone marrow transplant recipients were divided into those who had fully HLA-matched bone marrow (367 patients) and those who had one HLA mismatch (83 patients).
In both studies the cord blood recipients were younger, had more advanced disease at the time of transplantation, and had a lower median number of nucleated cells infused, compared with the recipients of bone marrow. In the Parisian study, the cord blood recipients also weighed less.
The Parisian study reports a lower incidence of acute graft versus host disease (GVHD) of grades II, III, or IV after cord blood transplantation, but neutrophil recovery was significantly delayed. There was no significant difference in the overall incidence of GVHD, transplantation-related mortality, relapse rate, and survival free of leukemia in the two groups.
The Cleveland study reports that hematopoietic recovery was slower among the patients who had undergone transplantation of mismatched bone marrow or cord blood, compared with those who had received matched marrow. Acute GVHD was more likely to occur after a mismatched transplantation and chronic GVHD was more likely to occur after cord blood transplantation. There were lower rates of mortality, treatment failure, and treatment-related mortality among the patients who received matched marrow transplants. There were comparable rates of treatment-related mortality and overall mortality among the patients who received either mismatched bone marrow or mismatched cord blood transplant. There were no differences in the groups in the rate of recurrence of leukemia, nor were there differences in outcomes after cord blood transplantation with either one or two HLA mismatches.
Both studies report that the transplantation of cord blood, even if HLA mismatched, should be considered as an acceptable treatment alternative in adults suffering from acute leukemia who have no HLA-matched adult donor. -PWF
Rocha V, et al. N Engl J Med 2004;351(22): 2276-85; Laughlin M, et al. N Engl J Med 2004; 351(22):2265-75.
INFLAMMATORY MARKERS AND CHD
Elevated levels of C-reactive protein are associated with significantly greater risk.
A study of the relationships among inflammatory markers soluble tumor necrosis factor-[alpha] receptor types 1 and 2 (sTNF-R1 and sTNF-R2), C-reactive protein, and interleukin-6 revealed that they, especially C-reactive protein, are associated with a greater risk of coronary heart disease (CHD).
The study population consisted of female participants in the Nurses' Health Study and male participants in the Health Professionals Follow-up Study, who provided blood samples and did not have cardiovascular disease at baseline. Researchers followed them for eight and six years, respectively, to determine the relationship between the development of nonfatal myocardial infarction or fatal CHD and levels of the inflammatory markers. Participants were matched for age, smoking status, and blood sampling date in a 2:1 ratio with randomly selected controls. Besides inflammatory marker levels, anthropometric, lifestyle, and dietary data also were collected.
The results showed that elevated levels of sTNF-R1 and sTNF-R2 were significantly associated with a greater risk of CHD, but only in women, while elevated levels of interleukin-6 and C-reactive protein were significantly associated with the greater risk of CHD in both women and men. After adjusting for various factors, such as alcohol consumption, lipid levels, and body mass index, only the association with the C-reactive protein level remained significant. Patients with high levels of it (3 mg/L or higher) were found to be at nearly 1.8 times greater risk for CHD, compared with those with low levels (lower than 1 mg/L).
According to the researchers, the measurement of the C-reactive protein level remained significant, along with the ratio of total cholesterol to high-density-lipoprotein cholesterol, might be a useful means of determining the risk of CHD.-JC
Pai JK, et al. N Engl J Med 2004;351(25): 2599-610.
THE BATTLE OF THE BULGE
Patients retain the benefits of bariatric surgery 10 years later.
The use of bariatric surgery to reverse obesity has received much attention in recent years as its popularity has grown. But whether it's more effective over time than conventional treatment with diet and exercise, in terms of both weight loss and health-related benefits, is in dispute. In order to answer the question, Swedish researchers examined follow-up data pertaining to both bariatric surgery patients and medically managed matched controls, all of whom had been enrolled in an earlier study, at two years and 10 years after the initial interventions.
Patients enrolled in the original study were given the choice of undergoing either bariatric surgery (fixed or variable gastric banding, vertical banded gastroplasty, or gastric bypass) or medical management (diet and exercise regimens, which were not standardized). The follow-up of each surgical patient and a matched control began on the day of the former's operation. Roughly one-quarter of the patients in each group was lost to 10-year follow-up, leaving 641 surgically treated subjects and 627 medically treated ones.
After 10 years, the surgically treated patients had maintained significant weight losses-25%, 16.5%, and 13%, among those who had undergone gastric bypass, vertical banded gastroplasty, and gastric banding, respectively--while patients in the control group had gained a mean of 1.6% of body weight at that point.
Further, glucose and insulin levels in the medically managed group were higher than at baseline after two and 10 years, but substantial decreases in both were seen in the surgically treated patients. Comparably favorable trends in uric acid, triglyceride, and HDL cholesterol levels also were seen among surgically treated patients. The incidences of hypertriglyc-eridemia, hyperuricemia, and diabetes were "markedly lower" among the surgically treated patients-but not among the controls-at both follow-up points, and comparable trends in the rates of recovery from those conditions also were seen.
The authors point out that bariatric surgery is not without risks--among the total number of surgical patients (N = 2,010, inclusive of those lost to either two- or 10-year follow-up), five (0.25%) died postoperatively, and postoperative complications (bleeding, embolism or thrombosis, wound complication, deep infection, pulmonary complication, and others) and the necessity of a second procedure have elsewhere been reported. -FM
Sjostrom L, et al. N Engl J Med 2004;351(26):2683-93.
CALFACTANT FOR ACUTE LUNG INJURY IN CHILDREN
Improvements are seen in oxygenation and the mortality rate.
The results of a randomized, controlled clinical trial of the effects of calfactant, a naturally occurring lung surfactant, reveal the favorable outcomes of improved oxygenation and decreased rates of death among children (including adolescents and infants) who received the treatment.
Twenty-one pediatric ICUs participated in the three-year study conducted from 2000 to 2003, in which 152 children, ages one week to 21 years and with acute lung injury that resulted in respiratory failure, were studied. The patients were stratified upon entering the study according to the degree of lung injury and then randomized to receive either calfactant (two 80 mL/m2 doses, administered 12 hours apart via endotracheal tube) or a placebo. The same treatment procedures were used in both groups, including alterations of bed position and the administration of sedation, neuromuscular blockade, and 100% oxygen. For the first half hour after each treatment, pulse oximetry and vital signs measurements were taken every five minutes and the short-term effect on the oxygenation index was obtained using those parameters (a higher one indicating greater oxygen requirements). Long-term outcomes were obtained from data concerning the number of days that the patient had been on the ventilator because of respiratory failure at the 28-day mark, the number of days spent in the ICU and in the hospital, overall, and hospital costs.
The mortality rate was found to be lower in the calfactant group (15 of 77 patients died), compared with the placebo group (27 of 75 died). Among infants less than one year old, who accounted for a quarter of the total study population, the mortality rate was more than three times lower in the calfactant group. Patients treated with calfactant experienced a mean decrease in oxygenation index of 6.1 points, compared with 5.4 points in the placebo group. Between the two groups, the difference in the number of days off ventilation was deemed statistically insignificant, as were the number of days in the ICU specifically and in the hospital overall, and hospital costs. The most common adverse effects of calfactant administration observed were hypoxia (in 12% of cases) and hypotension (in 9% of them).
The trial findings reinforce previous ones indicating that calfactant can improve lung function in patients with respiratory failure attributable to acute lung injury. However, the authors caution that the results concerning deaths observed in the study may have been affected by the inclusion of immunocompromised patients, a greater number of which were in the placebo group (30) than in the calfactant group (22).-AK
Willson DF, et al. JAMA 2005;293(4): 470-6.