Risk infection factors in the total hip replacement

Infection is a complication that occurs in a considerable percentage of hip prostheses replacements, being in many cases necessary to retire them, which generates important health and economical problems. Objectives: To know the distribution of infection and its risk factors in total hip replacement. Material and methods: A four year prospective study was developed in the rehabilitation and orthopedic center of La Paz Hospital. A total of 873 patients were included. Patients were controlled by means of active epidemiological surveillance until the day of discharge, listing up their characteristics at admission and risk factors during their stay. A multivariant study was carried out to determine risk factors. Results: Patients, average age was 63 years, 3.4% of them suffered from diabetes and there were no inmunocompromised patients. The percentage of wound infection during the four years was 6%, being reduced to 1.2% in the last year. The risk factors found in the multivariant study were: incorrect prophylaxis (OR: 3.85), wrong scaring (OR: 14.06), suffering more than one intervention (OR: 7.31) and a hospitalization period longer than 30 days (OR: 2.84). Conclusion: We think that special attention in the care of the surgical wound, as well as the correct use of prophylaxis, can significantly collaborate to the reduction of infection.     

Prevalence and control of arterial hypertension in the south-east of Spain: A radical but still insufficient improvement

Stroke mortality rates in Spain are one of the highest in all of Europe. At the same time, the Murcia region (south-east Spain) shows, for both genders, the highest age-adjusted stroke mortality rates in all of Spain. The earliest available hypertension figure estimations for this area go back to 1981, when a high prevalence combined with an almost nonexistent control was detected. One decade later, updated prevalence estimations of hypertension are presented jointly with their degree of control and their association with other risk factors based on the results of a prevalence survey in a random population sample (n = 3,091). Arterial blood pressure was measured following the MONICA protocol, maintaining a tight quality control on between and within-observer variability. As hypertensive was considered as any person with systolic blood pressure (SBP) 140 mmHg or with diastolic blood pressure (DBP) 90 mmHg or with antihypertensive pharmacological treatment. Detected prevalence rises to 32.3% (CI 95%: 29.1%–35.5%) among males and to 23.7% (CI 95%: 21.4%– 26%) among females, maintaining its level regarding figures observed back in 1981. However, its control has been increased, especially among hypertensive women [from less than 5% in 1981 to 35% (95% CI: 32%–37.8%) at present]. Hypertension is strongly associated to hipercholesterolemia, overweight, obesity and diabetes (p < 0.01). On the contrary, it shows an opposite association with current smoking, higher educational level and leisure time physical activity (p < 0.01). The highest educational level was associated with better hypertension treatment and control. In summary, while hypertension prevalence is stabilized in our population, its control has improved in a measurable but still insufficient way. These results are in accordance with a decreasing trend in stroke mortality registered in the Murcia Region along the last decade.     

Non-endotoxinic tumour necrosis factor-{alpha}-inducing factors in haemodialysis

A transmembrane passage of endotoxins may account for the dysfunctionof cytokine production which has been often reported in haemodialysis.We developed an assay based on the ability of patient serumto stimulate tumour necrosis factor (TNF) secretion in normalperipheral blood mononuclear cells. Three groups of subjectswere investigated: normal controls (n=14), patients with chronicrenal failure, CRF (n=15), and patients dialysed with poly-acrylonitrile(n=7), polysulphone (n=8), and cellulose acetate (n=7). Serafrom dialysed patients displayed a significantly higher TNF-inducingactivity than those of controls and CRF patients. The abilityof serum to elicit TNF secretion was neither modified duringthe dialysis session nor influenced by the type of haemodialysismembrane. TNF-inducing activity in serum was not inhibited bypolymyxin B, known to impair endotoxin-dependent cell responses,thus suggesting that it was not related to circulating endotoxins.We conclude that non-endotoxinic factors are present in serumfrom dialysed patients and are able to induce cytokine secretion.     

Some problems and some solutions in research on psychotherapeutic intervention in cancer

Several requirements of psychotherapeutic intervention (PI) research are presented. Some major problems are discussed. First, confidence in experimental results may be diminished by interference of possible confounders. A large number of these exist, both physical, perhaps more easily measurable, and psychological or psychosocial. Second, the value and limitations of randomization are presented, with special reference to small N. Validity and reliability are addressed, with emphasis on things that may dilute the strength of both of these measures. Natural remedies are proposed. Internal consistency and reliability are compared and cautions are given regarding their use and possible invalid substitution of consistency for reliability. Comparison of different PIs is commented on, with some relevant examples. Finally, a matter of special interest is discussed: the inconsistency between Spiegel's control survival curve and that produced from local population normative data.Presented at the Symposium Psychotherapeutic Interventions in Cancer Patients, Flims, Switzerland, 12–14 January 1995     

Occupational transmission of HIV in health care workers: A review

Health care workers have a small but real risk of acquiringHIV infection as a result of occupational exposure. In thispaper, we review all reports in the scientific literature from1984 through to December 1993 of confirmed and probable casesof HIV seroconversion after a specific occupational exposure.A total of 64 confirmed cases have been reported, 24 in Europe,36 in the USA and 4 in other countries. Most seroconversionshave resulted from percutaneous exposure (91%) to AIDS patients(62%), usually caused by hollow bore needlestick injuries inflictedduring blood drawing procedures. Almost all seroconversionshave been detected within 6 months of exposure (94%) and haveusually been preceded by an episode of acute illness (73%).Ten seroconversions have occurred in spite of partial or completecourses of zidovudine prophylaxis. An additional 113 probablecases have been reported, 75 in the USA, 35 in Europe and 3in other countries. Aggregating the results of the prospectivestudies carried out, it is calculated that the risk of seroconversionfollowing percutaneous exposure is 0.33% or 3 in 1000 exposures(95% Cl: 0.21–0.52%), while the risk following mucocutaneousexposure is much lower (0.04%, 95% Cl: 0.006–0.31%). Thedocumented failure of zidovudine prophylaxis following occupationalexposure in a number of instances indicate its effect is, atbest, only partial; furthermore, exposure to source patientswho have been receiving the drug may lead to transmission ofzidovudine-resistant strains of HIV. Risk factors for occupationalexposure to HIV and for transmission, given that an exposurehas occurred, are discussed.     

Genetic evolution of breast cancers III: Age-dependent variations in the correlations between biological indicators of prognosis

The influence of age on the occurrence of phenotypic features of prognostic significance was studied in relation to the DNA index values, measured on DNA histograms from a series of 1019 breast cancer patients. Globally, the distributions of all parameters showed variations with age, the most prominent being the decreases in the percentage of estrogen receptor-negative and high proliferative activity cases with increasing age. When analyzed according to the DNA index classes, all parameters were found to some extent linked with the stage of genetic evolution. However, the associations varied with age, defining two extreme groups. The younger patients (less than 40 years) presented a more complete acquisition of the aggressive phenotype and near-triploid tumors from this group were very frequently steroid hormone receptor-negative, high proliferation, and grade III. By contrast, near-triploid tumors in patients above 65 presented relatively frequently as receptor-positive, low proliferative activity, and even grade I. The correlation of the proliferative status with steroid hormone receptor content led to similar conclusions, high proliferation being more strongly correlated with the absence of estrogen and progesterone receptors in younger patients. Interestingly, the association between high proliferation and negative progesterone receptors was much weaker in patients above 55. Our results suggest that the currently established biological prognostic factors, including DNA profile, steroid hormone receptors, and histopathological grade, show patterns of association which vary with age. Of these, only progesterone receptor could be influenced by menopausal status. These findings have to be taken into consideration for future prognostic factor-related treatment decisions, but also for future methodological improvements of multivariate survival analyses.     

A study on how a 6-month aerobic exercise program can modify coronary risk factors depending on their severity in middle-aged sedentary women

It is well known that physical exercise can reduce coronary risk factors. But how an aerobic exercise modifies coronary risk factors in relation to severity and physical fitness is still controversial. Fifty-four middle-aged women (mean age, 55 years) completed a 6-month on-site and home-based anaerobic threshold-level exercise program. The changes in coronary risk factor profiles were observed during the pre-intervention and intervention periods. Before the intervention (during control period), most coronary risk factors showed a rather unfavorable trend. After the program, their mean body weight decreased from 56.7 to 55.7 kg (p>0.05) and the proportion of body fat from 30.9 to 27.9% (p>0.05) without any reduction in lean body mass. Systolic blood pressure (SBP) decreased from 129.0 to 125.0 mm Hg (p>0.05) and diastolic blood pressure from 79.5 to 76.6 mm Hg (p>0.05). Fasting plasma glucose (FPG) declined from 109.6 to 103.4 mg/dl (p>0.05). Changes in SBP and FPG were most remarkable in their respective worst tertile. Serum lipids improved only modestly. Maximum oxygen uptake increased from 23.6 to 26.1 ml/kg/min (p>0.01). However, no significant correlations were found between changes in coronary risk factors and those in physical fitness. We conclude that the 6-month aerobic exercise program would modify women’s coronary risk factors depending on their initial values, probably independently of the changes in physical fitness.     

Different pattern of risk factors for atopic and nonatopic asthma among children – report from the Obstructive Lung Disease in Northern Sweden Study

BACKGROUND: A cross-sectional study was performed among 78-year-old schoolchildren during the winter of 1996 in three municipalities in the most northern province of Sweden, Norrbotten. The study was the starting point of a longitudinal study of asthma, rhinitis, eczema, and type-1 allergy, and provided data on prevalence and risk factors for these conditions. The aim of the present study was to validate the classification of asthma based on a parental questionnaire, and to examine risk factors for atopic and nonatopic asthma. METHODS: The ISAAC questionnaire with additional questions was distributed by the schools to the parents. The response rate was 97%, and 3431 completed questionnaires were returned. The children in Kiruna and Lule? were also invited to be skin tested, and 2149 (88%) were tested with 10 common airborne allergens. A structured interview was administered by pediatricians in stratified samples of the children to test the validity of the diagnosis of asthma based on the questionnaire. RESULTS: After the validation study, the prevalence of "ever asthma" was estimated to be 8.0%. The specificity of the question, "Has your child been diagnosed as having asthma by a physician?", was high, >99%, while the sensitivity was around 70%. The strongest risk factor for "ever asthma" was a positive skin test (OR 3.9). Risk factors for asthma in the asthmatics who were not sensitized were family history of asthma, OR 3.6; breast-feeding less than 3 months, OR 1.8; past or present dampness at home, OR 1.8; smoking mother, OR 1.7; and male sex, OR 1.6. Among the sensitized asthmatics, only a family history of asthma was a significant risk factor (OR 3.0), while breast-feeding less than 3 months was not associated with an increased risk (OR 1.0). A synergistic effect between genetic and environmental factors was found especially in the nonatopic asthmatics; the children with a family history of asthma who had a smoking mother and past or present dampness at home had an OR for "ever asthma" of 13. CONCLUSIONS: Different risk-factor patterns were found for asthma and type-1 allergy. In addition, the risk factors for atopic or allergic asthma diverged from those for nonatopic asthma.     

Reflex testing I: algorithm for lipid and lipoprotein measurement in coronary heart disease risk assessment

We reviewed the current literature in order to construct a reflex testing algorithm that maximizes clinical utility and cost-effectiveness of lipid and lipoprotein testing. The algorithm was based on the 2nd Report of the National Cholesterol Education Program Adult Treatment Panel guidelines for use of total cholesterol (TC), triglycerides (TG), HDL-C, and LDL-C, and published reports describing the clinical use of apolipoprotein B and lipoprotein (a). The success of this algorithm was tested in a low-risk general and a high-risk hyperlipidemic patient population. Lipid data and non-lipid risk factors were obtained from a national database and from patients seen at two lipid clinics. A total of 16 968 individuals from the National Health and Nutrition Examination Survey III database comprised the low-risk group, and 239 patients examined in the Hartford Hospital and Washington University Lipid Clinics comprised the high-risk group. We found a solid scientific base to support the NCEP guidelines and reasonable support for limited testing of apoB and Lp(a). According to the algorithm, the direct LDL-C assay was deemed unnecessary in 98% and 91% of low- and high-risk subjects, respectively, if one assumes that the Friedewald equation is adequate with TG≤4.00 g/l. With a more conservative cutoff of TG≤2.50 g/l, the algorithm canceled 92% and 81% of direct LDL tests, respectively. The algorithm also limited TG to 20 and 64%, apoB to 6 and 20%, and Lp(a) to 15 and 56%, of low- and high-risk groups, respectively. Use of a comprehensive, reflex algorithm for coronary heart disease risk assessment will substantially reduce the utilization of laboratory services without diminishing the clinical value of these tests. The algorithm will prevent the overuse of certain expensive tests (direct LDL) while promoting the limited use of underutilized tests [apoB and Lp(a)].