AUTOMATION OF UTI MONITORING

PDAs might serve as a cost-effective means of surveillance.

In a recent study, researchers who assessed the joint use of handheld personal digital assistants (PDAs) and surveillance by computer in the identification of nosocomial urinary tract infection (UTI) in a critical care population found it to be nearly as accurate, less time-consuming, and less costly than observation by an infection control practitioner (ICP).

The researchers selected patients who had had a urinary catheter in place for more than 48 hours and were in the medical intensive care unit (MICU) for at least that long, excluding from the evaluation those who had a urine culture positive for UTI within the first 48 hours of admission. Data were collected independently over the course of one month by an ICP (the traditional approach) and by a research assistant using a PDA and a computer (the technologic approach). The ICP performed daily rounds among the eligible MICU patients, identifying clinical indicators of UTI such as duration of catheter placement, urine culture results, diagnoses, and symptomatology. The ICP continued to monitor patients for seven days after the removal of catheters, and all data were entered manually into a database. In the technologic approach, the gathering of data entailed first uploading the MICU patient information into the PDA, then downloading it from there into a database. A research assistant obtained the number of days of catheter placement from the patient's bedside chart and entered it into the PDA and then downloaded it into the database. By daily automatic query, the password-secured database extracted microbiology reports of all positive urine cultures in the group of eligible patients.

The ICP approach identified eight cases of nosocomial UTI during the study period. Three cases were considered to be attributable to urinary catheter placement, and the remaining five cases were excluded because the diagnoses were made within 48 hours of the patient's admission to the MICU. Comparatively, the PDA approach also identified the eight patients with UTI and correctly excluded the five who did not meet the established criteria. The ICP, however, was able to correctly specify the unit on which the infection originated, whereas the PDA inaccurately associated two of the three infections with units outside the MICU because of errors in programming.

The researchers note that the joint use of the PDA and computer saved approximately 6.5 hours per week in time spent collecting and evaluating data, compared with ICP surveillance, and that, although such use would entail a considerable initial financial investment, hospitals could realize significant savings by the fourth year, especially if the practice was implemented on several units. In addition, the researchers note that the study was limited in scope by a short time period during which no patients were diagnosed purely according to clinical symptoms-had some such cases been included, the PDA and computer surveillance method may have proven to be less accurate than the findings indicate.

Farley JE, et al. Am J Infect Control 2005;33(8):444-9.

PULMONARY ARTERY CATHETERS

Investigative study challenges appropriateness of routine use.

Researchers in the Evaluation Study of Congestive Heart Failure and Pulmonary Artery Catheterization Effectiveness (ESCAPE) trial found that the use of pulmonary artery catheters (PACs) in critical care patients did not improve overall mortality and led to a greater number of adverse events, eliciting the conclusion that they should not be used routinely to guide the treatment of patients with advanced heart failure.

The ESCAPE trial was a large, randomized, controlled study conducted over a period of nearly three years in 26 institutions in North America, into which 433 patients diagnosed with advanced and symptomatic heart failure were recruited. Upon enrollment, the patients were randomly divided into two groups, one in which clinical judgment alone served as the basis for treatment decisions and another in which clinical judgment and also PACs were used for that purpose. The goal of therapy in both groups was improvement in the signs and symptoms of congestion, and in the PAC group the attainment of certain hemodynamic parameters was also sought. The researchers didn't determine the medications or therapies used but strongly discouraged the use of inotropes in favor of diuretic and vasodilator therapies.

The trial's primary end point was the number of days the patient survived out of the hospital during the first six months after enrollment. In that measure, there was no difference between the PAC group and the control group, nor were there differences in mortality rate or the duration of hospitalization. Secondary end points of the study included the quality of life and physiologic measures; there were improvements in both groups, although more substantially in the PAC group. Specifically, at three measurement time points, PAC patients scored better on a "time tradeoff" questionnaire designed to ascertain the survival time a patient would exchange for a higher quality of life.

The study also revealed a greater number of adverse events in the PAC group, the majority of them attributable to catheter infection, a finding that was cited as one reason that the trial recruitment was stopped prematurely.

Because decreased congestion that reduced symptoms was attained in both groups, and there was no difference in the primary end point between them, the researchers conclude that the use of the PAC is not routinely necessary to guide treatment of advanced heart failure, especially in light of the greater risk of adverse events. It may be considered, however, in patients with advanced heart failure when traditional therapies have proven ineffective and the information obtained is to be used for the purpose of making treatment decisions.

Binanay C, et al. JAMA 2005;294(13): 1625-33.

DYSPNEA AND CARDIAC STRESS TESTING

Higher mortality rates are seen.

According to a recently published study conducted in a population of patients who underwent myocardial-perfusion single-photon-emission computed tomographic (SPECT) stress testing, those with dyspnea were at much greater risk for death, as compared with those with or without symptoms of angina.

Researchers evaluated data on 17,991 patients, collected over nearly 10 years. Each patient underwent SPECT stress testing both at rest and with either exercise or a vasodilator to elicit stress response, after which the researchers classified him into one of five categories according to the following symptoms: typical angina (chest pain with three attendant factors: substernal location, occurrence upon exertion, cessation within 10 minutes after either rest or nitroglycerin administration), atypical angina (chest pain with only two of the factors), nonanginal chest pain (chest pain with one or none of the factors), dyspnea (no chest pain, only shortness of breath), and no symptoms. Patients with coronary artery disease (CAD) were analyzed independently of those who were not known to have it at the time of testing.

The researchers followed up each patient-at a mean of 2.7 years after stress testing-by mail or telephone, or according to death reports obtained through a hospital database and the Social Security Death Index.

The analysis revealed an overall higher risk of death attributable to cardiac causes or any cause in patients in the dyspnea category (both in the presence and absence of CAD). Perhaps the most notable finding was the four times higher risk of death from a cardiac cause in the dyspnea category, in comparison with the asymptomatic category, among patients without CAD. The risk of death was two times higher within that subset when compared with the typical angina category.

The researchers note that one limitation of the study is the possible inadvertent exclusion of other clinical factors that may have affected the analysis of patients in the dyspnea category. Nevertheless, they conclude that clinicians should thoroughly assess for dyspnea in patients undergoing stress tests, as the risk of death in patients with dyspnea apparently is greater than it is in patients with anginal symptoms or no symptoms.

Abidov A, et al. N Engl J Med 2005; 353(18):1889-98.

GLUCOSE LEVELS AND TRAUMA PATIENTS

Could higher glucose levels be associated with higher mortality rates?

A recent study found that trauma patients with persistent hyperglycemia during the first week of a stay in the ICU have higher mortality rates, longer hospital and ICU stays, and longer durations of ventilation, as compared with those with either low glucose levels or levels that improved.

The findings were based on research involving 942 trauma patients consecutively admitted to the surgical ICU over a period of two years, of whom approximately three quarters were male and 71% had sustained blunt trauma injuries. Patients with a prior diagnosis of diabetes were excluded from the study. The subjects were stratified according to daily blood sugar levels obtained during the first week of ICU admission, ranging from low (139 mg/dL or less) to moderate (140 to 219 mg/dL) to high (greater than 220 mg/dL), and also according to patterns in glucose level (that is, if it either improved or worsened with time or was greatly variable). Of the total number of patients, 66% were categorized into the low and "improving" glucose level groups, and a much smaller percentage (7%) constituted the consistently moderate and high glucose level groups.

The results indicate that, among the patients with moderate, high, worsening, or greatly variable blood sugar levels, hospital and ICU stays as well as periods of ventilation were longer, and infection and mortality rates were higher, compared with those with low or improving blood sugar levels. Notably, among patients with high blood sugar levels, the rate of respiratory infection was 50%, compared with 27% among those with low blood sugar levels (the rate was 46% among patients with moderate levels, and 44% among those with worsening or greatly variable levels). The highest mortality rate, 25%, was observed in patients in whom blood sugar levels rose throughout the week. In comparison, that rate was 6.8% in the low blood sugar level group.

The authors acknowledge the need for further study of the outcomes associated with the implementation of tight glucose control in this population. However, their study's results should alert ICU nurses to the possible detrimental outcomes in trauma patients with sustained hyperglycemia, therefore frequent measurement and control of blood glucose levels should be a priority in management.

Bochicchio GV, et al. J Trauma 2005;58(5): 921-4.

UTI IN CHILDREN

Improper antibiotic regimens can result in non-E. coli infections.

The rate of urinary tract infections (UTIs) in children caused by organisms other than Escherichia coli may be increasing, and according to a recent study, this may be in part due to the improper use of antibiotics in this population.

The study was conducted at a pediatric hospital over two years; 158 children under 18 years of age and with community-acquired UTI confirmed by urine culture were enrolled. The researchers collected hospital data concerning variables such as demographics and prior use of antibiotics or prior hospitalizations, as well as culture and other laboratory results. Once the infectious organisms were identified, the subjects were stratified into two groups for analysis-those with E. coli-related infections and those with infections attributable to other organisms.

The mean age of the children was 31.2 months, 85% of them were under five years of age, and 56% were female. Of the 175 cases of UTI documented, 60% were caused by E. coli. (Compare that with 25% in a study by the same authors conducted in the '80s.) Analysis indicated several defining characteristics in the remaining group of non-E. coli cases, in which 30% of the infections occurred in children who had used antibiotics within the preceding 30 days (compared with 9.5% in the E. coli group), and 22.9% of the patients had used antibiotics prophylactically in the past (compared with 6.7% in the E. coli group). Also, male patients were more likely to present with a non-E. coli infection (57.1%, compared with 35.2% in the E. coli group). Among children with an underlying renal abnormality there also was a higher percentage of non-E. coli UTIs (65.7%), compared with those in the E. coli group (44.8%). After multivariate regression analysis, three of the characteristics, previous antibiotic therapy within the preceding 30 days, male sex, and underlying renal abnormality were identified as independently predictive of non-E. coli UTI.

Antibiotic regimens often are administered on an empirical basis, without confirmation of the offending organism, and 18.6% of subjects with non E. coli UTI were improperly treated, compared with only 1.9% in the E. coli group.

The authors conclude that greater awareness among health care professionals of the independently predictive factors in non-E. coli UTI may help them to select and administer more appropriate antibiotic regimens for the treatment of the condition in children.

Marcus N, et al. Pediatr Infect Dis J 2005;24(7):581-5.

CARDIAC, ABDOMINAL, OR PELVIC TRAUMAS

They might increase the risk of acute MI.

Trauma patients may have more to be concerned with than surviving the initial injury, according to a new study that found the risk of suffering a heart attack can increase significantly after either a blunt cardiac injury or a traumatic abdominal or pelvic injury.

The research was based on a retrospective analysis of data obtained from approximately 1 million patient discharge records in 19 states. The data were analyzed according to the International Classification of Diseases, 9th Revision, Clinical Modification coding of injury diagnosis and other events related to hospitalization. Because blunt cardiac injury often resembles acute myocardial infarction (AMI), physiologically, patients were evaluated according to whether the heart attack was verified by coronary arteriography, and further divided into subgroups according to age (45 years and younger or 46 years and older). The researchers assessed the data both with and without adjustments for possible confounding variables, such as the severity of injury, alcohol use, and sex.

The records revealed that 3.1% of all injury patients suffered an AMI during hospitalization and 49% of them had been admitted after a fall. When stratified by age, falls were still the leading cause of injury in the older group of patients discharged with AMI; however, among patients 45 and younger, injury resulting from a transportation incident was the primary cause.

The study revealed also that the adjusted risk of AMI was 2.6 times greater in patients 46 and older with blunt cardiac injury, and 8.1 times higher when its occurrence was verified by arteriography. When AMI was verified by arteriography in the group of patients 45 and younger with blunt cardiac trauma, the risk was 31 times higher. The trend continued in abdominal or pelvic trauma: when confounding variables, including coronary arteriography, were controlled for, there was a 65% higher risk of AMI among patients 45 and younger, and a 93% greater risk among those 46 and older.

Because the study suggests that trauma to the heart or abdominal region puts patients at greater risk for AMI, trauma nurses should be particularly alert to cardiac symptoms in those populations. The authors suggest that such patients might benefit from cardiac work-up in consideration of the possible risk.

Ismailov RM, et al. Intl J Cardiol 2005; 105(2):141-6.

INACTIVE DRUG INGREDIENTS

Some 'fillers' contain food allergens.

In addition to active ingredients that produce therapeutic effects, drugs contain inactive ones, some of which are chemicals derived from food that most patients with mild food allergies can tolerate---but those with more severe allergies might react adversely to them.

For example, there have been reports of patients with severe milk protein allergies having serious allergic reactions after taking the combination antiasthmatic drug, fluticasone propionate and salmeterol (Advair Diskus), which contains a lactose filler. To compound the problem, the amount of an inactive drug ingredient can vary between lots and, therefore, a patient who takes a prescribed medication safely can have an allergic response to it at a later point, a circumstance described in some case reports concerning the latter drug.

Other dry powder inhalers that contain milk protein are salmeterol xinafoate (Serevent Diskus) and formoterol fumarate (Foradil Aerolizer). Another inactive filler is casein, one of the two principal allergens found in milk protein, and one case report cited an allergic reaction that occurred after ingestion of Chewable Calcium 600 with Vitamin D, in which sodium caseinate (the salt form of casein) is one of the inactive ingredients. Unless one is knowledgeable in the terms denotive of milk proteins, allergic reactions to them can occur despite close monitoring. The latter incident illustrates the problem, as the container label of the vitamin states that it is "free of . . . dairy," yet sodium caseinate is listed in the smaller print of the "other ingredients" section.

Routinely, nurses should inquire about their patients' food allergies and assess for the possibility of related drug allergies. If the patient has a history of a food allergy, the severity of the allergic reaction should be determined. Nurses should check drug prescribing or labeling information for inactive ingredients if the patient reports a history of a severe food allergy, and consult with a pharmacist or allergist to interpret such information and determine whether the patient is at risk for having an allergic reaction to a medication. Nurses should teach patients and their families the terms that are denotive of the pertinent food allergen and instruct them to read drug labels closely, including those of over-the-counter drugs. Patients who have severe allergic reactions to a certain food should carry an epinephrine auto-injector (Epipen) in case of exposure to an allergen. -Diane S. Aschenbrenner, MS, RN, CS

Mahmud AR, Holquist C. Drug Topics 2005 Jan 10. http://drugtopics.com/drugtopics/article/articleDetail.jsp?id=141579.