Cholesterol and serum albumin as risk factors for death in patients undergoing general surgery.

BACKGROUND: Serum levels of total cholesterol, its fractions (high-density lipoprotein-cholesterol (HDL-C) and low-density lipoprotein-cholesterol) and albumin are related to a poor outcome during hospital stay. It has been not assessed whether they are related to death in the long term after general surgery. METHODS: This prospective cohort study included 2848 general surgical patients with a median follow-up of 6 years after discharge from hospital. Sampling for biochemical measurements was done at the time of admission. The outcome investigated was all-cause mortality and multivariable Cox regression was used for statistical analysis. RESULTS: Three hundred and seventy-eight patients (13.3 per cent) died during follow-up. Serum albumin (adjusted hazard ratio (HR) 2.2 (95 per cent confidence interval (c.i.) 1.5 to 3.4) for lowest versus highest quintile), total cholesterol (HR 1.6 (95 per cent c.i. 1.1 to 2.3) for lowest versus highest quintile) and HDL-C (HR 1.6 (95 per cent c.i. 1.1 to 2.4) for lowest versus highest quintile) showed a significant inverse relationship with all-cause mortality in both crude and multivariable analyses. Serum albumin and HDL-C were associated with death for up to 2 years after surgery, whereas total cholesterol had the strongest association more than 2 years after discharge. CONCLUSION: Low levels of serum albumin, total cholesterol and HDL-C are associated with death after discharge from hospital in patients having general surgery.

Alteraciones del desarrollo mamario / Aberrations of normal breast development

La glándula mamaria es, en nuestra especie, algo más que un simple órgano productor de leche. Desempeña un papel importante como órgano sexual y está sometido a la variabilidad de los cánones de belleza impuestos por las distintas modas. Las alteraciones mamarias se dividen en aquellas que aparecen desde el nacimiento (congénitas) y las provocadas por un mal desarrollo (adquiridas). Ambas pueden resultar bien por un exceso o por un defecto tanto en su número como en su crecimiento o tamaño y afectar a toda la mama o limitarse al complejo areola pezón (AU)

Procesos inflamatorios de la mama / Inflammatory diseases of the breast

Las enfermedades inflamatorias de la mama o mastitis suponen la respuesta clínica a la agresión infecciosa, tumoral, traumática o de otro tipo sobre la mama. La mastitis puerperal es el proceso más frecuente. Se clasifican en agudas y crónicas y estas últimas abarcan una serie de procesos específicos e inespecíficos. En la mastitis aguda el diagnóstico es clínico y el tratamiento médico salvo cuando existe un absceso cuyo tratamiento es el drenaje quirúrgico. El germen más frecuentemente aislado es el Stafilococo aureus. En las mastitis crónicas es necesaria, en muchos casos, una biopsia para establecer un diagnóstico diferencial con el cáncer de mama. El tratamiento es frecuentemente médico pero en muchos casos es preciso realizar una tumorectomía llegando en casos extremos a precisar de mastectomía simple. Algunos procesos inflamatorios están limitados al complejo areola-pezón (AU)

Alcohol consumption and the risk of nosocomial infection in general surgery.

BACKGROUND: Alcohol consumption increases community-acquired infections and affects the immune system. The aim of this report was to analyse whether drinking increases the risk of nosocomial infection. METHODS: This was a prospective study of 1505 patients admitted consecutively to a general surgical department. Alcohol consumption was assessed by a structured questionnaire. Postoperative infection was classified using the Centers for Disease Control criteria. Confounding was controlled for by logistic regression analysis, and the results were stratified by gender and drinking pattern. RESULTS: Most women were light drinkers and no increased risk of postoperative infection was noted. In men, drinking was associated with a lower American Society of Anesthesiologists grade and fewer co-morbidities. Heavy alcohol consumption (more than 108 g/day) in men increased the rate of all-site nosocomial infection (adjusted odds ratio (OR) 2.51, 95 per cent confidence interval (c.i.) 1.06 to 5.96) and the rate of in-hospital surgical-site infection (SSI) (adjusted OR 2.16, 95 per cent c.i. 0.84 to 5.58). An intake of above 72 g/day increased the rate of lower respiratory tract infection (adjusted OR 5.22, 95 per cent c.i. 1.04 to 26.2). Alcohol consumption was not related to the rate of SSI after hospital discharge. When drinking was limited to weekends, there was no relationship with nosocomial infection. CONCLUSION: Heavy alcohol consumption increased the risk of nosocomial infection in men who underwent general surgical procedures.

Relationship between hospital infection and long-term mortality in general surgery: a prospective follow-up study.

A prospective study of 1431 patients admitted to a general surgery department were followed up for a median of 6.2 years after discharge (7679 person-years of follow-up). We collected information on underlying conditions, including severity of illness, and healthcare-related variables. Relative rates of death and their 95% confidence interval (CI) were estimated using person-years as the denominator. Multiple-risk factors adjusted for relative rates (RR) were obtained using Poisson regression analysis. There were 172 deaths during the follow-up period after hospital discharge (2/100 person-years). Follow-up was complete in 91% of the cohort. There were no important differences in demographic characteristics or risk factors between patients followed up and those lost to follow-up. The death rate in patients with any hospital-acquired infection was 5.3/100 person-years, and the relative rate was 3.07 (95% CI: 2.20-4.24). After adjusting for the main predictors of mortality, we found an effect modification by the presence of chronic disease (P = 0.01 for the product-term between hospital infection and the diagnosis of chronic diseases). Among patients without any underlying chronic disease, hospital-acquired infection was related to a significantly higher long-term mortality (RR = 2.47, 95% CI: 1.24-4.91). In these patients, surgical wound infection yielded a RR of mortality of 3.44 (95% CI: 1.63-7.27). Among patients with underlying chronic disease no association between hospital infection and long-term mortality was found. No evidence of an important modification of the relative rate along the follow-up period was observed. In conclusion surgical patients without chronic disease developing hospital-acquired infection have an increased risk of long-term mortality.

Quimioprofilaxis en cirugía: problemas y soluciones en su cumplimiento / Chemoprophylaxis in surgery: problems and solutions in its performance

Desde hace 20 años los principios de la profilaxis antibiótica permanecen vigentes. No obstante, con una gran frecuencia en todos los países, desarrollados o no, se documenta que su incumplimiento es una práctica habitual en cirugía. Los estudios que han abordado el estudio de los determinantes de cumplimiento son escasos. Aunque la información es insuficiente, se ha establecido una serie de factores que pueden influir. Dentro de los factores relacionados con el paciente se encuentran el sexo, el grado de contaminación y la duración de la cirugía, si la cirugía es de urgencia o programada, el momento del día en que se realiza la cirugía, el nivel ASA y la enfermedad subyacente. Dentro de los factores dependientes del cirujano pueden influir el dogmatismo, nihilismo, arrogancia, miedo al fracaso, mercadotecnia de las casas comerciales, sensación de seguridad, falta de formación científica, no diferenciar profilaxis de tratamiento, no diferenciar inflamación de infección, trabajar o no en un hospital docente y la comprobación de que la alteración de la profilaxis recomendada no aumenta el riesgo de infección. Para conseguir que se cumplan las normas de profilaxis antibiótica se sugiere una serie de soluciones, que van desde la evaluación del grado de cumplimiento hasta el aumento de la formación científica, especialmente en la residencia donde el futuro cirujano es más moldeable y adopta las prácticas de sus tutores. (AU)

Efficacy of surveillance in nosocomial infection control in a surgical service.

OBJECTIVE: The purpose of this study was to assess the efficacy of surveillance of nosocomial infection in infection control at a service of general surgery. DESIGN: A surveillance study that included 1483 patients with a prospective identification of nosocomial infection was carried out. Its results were discussed with the staff, and a program on nosocomial infection control was implemented. One year after the pre-intervention study, a similar study that included 1506 patients was done. The main outcome measure was nosocomial infection. Incidence rates, incidence rate ratios, crude and multiple-risk factor adjusted for by Poisson regression analysis, and their 95% confidence interval rates were estimated. RESULTS: The characteristics of the patients enrolled in both studies were compared. After the intervention, the trend was to attend patients with more severe conditions: higher frequency of liver failure, chronic obstructive lung disease, higher proportion of dirty surgical wounds, and higher scores of both Study on the Efficacy of Nosocomial Infection Control (SENIC) and National Nosocomial Infections Surveillance indices. There were no significant differences in emergency surgery, duration of surgery, age, and sex. After the intervention, unnecessary chemoprophylaxis was drastically reduced, and a significant reduction in preoperative stay was observed. The nosocomial incidence rate fell from 18.4 to 14 per 1000 patient-days. This reduction yielded an incidence rate ratio of 0.56 (95% confidence interval, 0.43%-0.74%) adjusted for several variables (SENIC index, serum creatinine level, serum albumin level, antihistamine H2 level, surgical wound, body mass index, chemoprophylaxis, and community-acquired infection). Significant reductions in surgical site infection and urinary tract infection were observed, but the rate of respiratory tract infection remained unchanged. CONCLUSIONS: Surveillance was effective in reducing nosocomial infection.

[The usefulness of intrinsic risk factors of infection of the surgical site as predictors of other infections and death]. / Utilidad de los indicadores de riesgo intrínseco de infección del sitio quirúrgico como predictores de otras infecciones y muerte.

BACKGROUND: The use of two indices of patient intrinsic risk of surgical site infection, the SENIC index and the NNIS index, have been recommended to adjust for the case-mix and improve the comparability of infection rates across different hospitals. We assess the usefulness of the indices in predicting other infection sites and in-hospital death. METHODS: A prospective study on 1,483 patients admitted to a service of general surgery was performed. The outcomes were nosocomial infection and in-hospital death. Relative risk and its 95% confidence interval were estimated. Unconditional logistic regression analysis was used to adjust for potential confounders. RESULTS: In the follow-up, 155 surgical site infections (10.5%), 19 postoperative pneumonias (1.3%), 33 urinary tract infections (2.2%) and 33 in-hospital deaths (2.2%). Both the NNIS index and the SENIC index showed a clear trend with infection risk and death; the higher the index, the higher the risk. After controlling for several confounders, the association was still observed. To assess whether the SENIC index added predictive power to the NNIS index (and vice versa) a linear regression analysis of the SENIC index on the NNIS index. A set of residuals (difference between the observed and expected values according to the regression equation) were estimated. In the logistic regression models, residuals of the NNIS index (part of the NNIS index unrelated to the SENIC index, whereas the residuals of the SENIC index did not increase the predictive power of the NNIS index. CONCLUSIONS: Both the SENIC index and the NNIS index are independent predictors of several sites of nosocomial infection and in-hospital death. The NNIS is a better predictor than the SENIC index.

Usefulness of intrinsic infection risk indexes as predictors of in-hospital death.

OBJECTIVE: Comparison of two measures of intrinsic infection risk for predicting in-hospital mortality risks among subjects undergoing general surgery: the Study on the Efficacy of Nosocomial Infection Control (SENIC) index and the National Nosocomial Infection Surveillance (NNIS) index. DESIGN: Prospective cohort study on 1483 patients admitted to the service of general surgery of a tertiary hospital. The main outcome measure was in-hospital death. Relative risks, crude and multiple-risk factor adjusted for by logistic regression analysis, and their 95% CIs were estimated. RESULTS: During follow-up, 33 patients (2.2%) died. Both the SENIC and the NNIS indexes appeared related to in-hospital mortality risk in crude data. After several confounders (age, sex, severity of illness, American Society of Anesthesiologists score, serum creatinine, serum albumin, stay at the intensive care unit, length of operation, type of surgical wound, and preoperative stay) were controlled for, the SENIC index showed a borderline significant trend with mortality (p = 0.052), whereas the trend was significant for the NNIS index (p = 0.026). The NNIS index also showed a linear trend with both crude and adjusted for (SENIC index) risk of death. The SENIC index did not exhibit any linear trend with adjusted for (NNIS index) risk of surgical wound infection. To delineate whether the SENIC index added explanatory information to the NNIS index (or vice versa), we regressed the SENIC index on the NNIS index (and vice versa) and computed a set of residuals for both indexes. In logistic regression analyses, the residuals of NNIS index added meaningful information to the SENIC index, whereas the residuals of the SENIC index did not add any relevant information to the NNIS index. These results remained unchanged after controlling for several confounders. CONCLUSIONS: Both the SENIC and the NNIS indexes are good predictors of in-hospital mortality risk. The NNIS index had greater capability for discriminating and predicting risk of dealth.

Comparison of two procedures to estimate the hospital stay attributable to nosocomial infection: matched cohort study versus analysis of covariance of the total unmatched cohort.

We compare the results of a matched cohort study with those yielded by analysis of covariance (ANCOVA) in the cohort where the matched study was nested to assess whether the matching design underestimates (as it has been assumed) the extra length of hospitalization due to nosocomial infection. A total of 218 patients developed hospital infection in a cohort of 1483 general surgery patients; 161 were successfully matched 1:1 for surgical procedure, ASA score, age (+/-10 years), emergency-scheduled surgery, preoperative stay, and, whenever possible, number of diagnoses and sex. Unmatched infected patients (57, 23.1%) were different from matched ones. There were no differences for the variables between matched infected patients and their pairs. The matched cohort study overestimates the extra LOH due to hospital infection. The use of ANCOVA in the total cohort obviates the selection bias of the matched cohort design.

Usefulness of intrinsic surgical wound infection risk indices as predictors of postoperative pneumonia risk.

The main objective of this report was to use two indices of intrinsic surgical wound infection risk, the SENIC index (Haley et al., 1985) and the NNIS index (Culver et al., 1991), to predict risk of postoperative pneumonia in general surgery patients. A prospective cohort study on 1483 patients admitted under the general surgery speciality of a tertiary hospital was performed. The main outcome measure was postoperative pneumonia. Relative risk and their 95% confidence intervals (CIs) were estimated. Stepwise logistic regression analysis was used to select the main determinant predictors. During follow-up, 19 (1.3%) patients acquired postoperative pneumonia. Common risk factors of postoperative pneumonia were identified: mechanical ventilation, age, upper abdominal surgery, severity of illness, obesity, hypoalbuminaemia, and use of histamine type 2 receptor antagonists. Both the SENIC and the NNIS indices showed a statistically significant association (P < 0.001) with postoperative pneumonia risk: the higher the score the greater the risk. Stepwise logistic regression analysis selected five variables: (1) mechanical ventilation [odds ratio (OR) = 9.8, 95% CI 2.7-35.6]; (2) upper abdominal surgery (OR = 4.7, 95% CI 1.6-13.9); (3) chronic lung disease (OR = 5.9, 95% CI 1.7-21.2); (4) the NNIS index (OR for each point = 2.2, 95% CI 1.1-4.4); and (5) obesity, measured by a body mass index greater than the 90th percentile (OR = 2.9, 95% CI 0.9-9.4). In conclusion, both the SENIC and the NNIS indices were related to postoperative pneumonia risk. The NNIS index may be a better predictor.

[Incidence of nosocomial infection surveillance in general surgery]. / Frecuencia de la vigilancia de la infección nosocomial en cirugía general.

BACKGROUND: We have not found any study assessing the sensitivity of different frequencies of nosocomial infection surveillance (NIS). The objective of this study is to contribute to the ascertainment of the frequency of the NIS surveillance in surgical patients, where NIS has shown to be most efficient. METHODS: A prospective cohort study on 1,483 patients undergoing general surgery in a reference hospital was performed between November 1992 and July 1994. A daily NIS, plus review of clinical chart after hospital discharge, performed by two trained clinicians was taken as gold standard. The expected number of infections detected according to different schedules of NIS (from a minimum of weekly examination to a NIS performed every other day) was estimated taking into account the duration of infection and the hospital stay after infection healing. This number was corrected multiplying it by 0.9 (sensitivity of NIS without reviewing clinical chart after discharge). Confidence intervals (CI) were estimated using the binomial's exact method. RESULTS: 235 nosocomial infections were detected by the gold standard. The sensitivity of the weekly NIS for all infections was 78.3% (95% CI = 72.5-83.4); it varied from 63.6% (95% CI = 45.1-79.6) for urinary tract infections (UTI) to 85% (95% CI = 62.1-96.8) for respiratory tract infections; for surgical wound infections, it was 80.1% (95% CI = 72.4-86.5). As expected sensitivity increased with the frequency of NIS. A frequency of NIS every four days yielded a sensitivity for all infections of 86.4% (IC 95% = 81.3-90.5), 78.8% (CI 95% = 61.1-91.0) for UTI and 86.8% (CI 95% = 79.9-92.0) for SWI. CONCLUSIONS: Most nosocomial infections were detected by one visit a week. Twice visits a week improved the sensitivity of NIS in about 10%. It is important to emphasize that results change according to duration of infection and post-discharge hospital stay.

Total cholesterol, HDL-cholesterol, and risk of nosocomial infection: a prospective study in surgical patients.

OBJECTIVE: To study the relationship between serum high-density lipoprotein cholesterol (HDL-C), total serum cholesterol, and nosocomial infection in patients undergoing general surgery. DESIGN: Prospective cohort study, with an extended follow-up to 1 month after hospital discharge. SETTING: The general surgery service of a tertiary hospital. MAIN OUTCOME MEASURE: Nosocomial infection, mainly surgical-site infection (SSI), urinary tract infection, respiratory tract infection (RTI), and bacteremia. PATIENTS: 1,267 surgery patients aged 10 to 92 years. RESULTS: 182 subjects acquired 194 nosocomial infections, a cumulative incidence of 14.5%; most (116, 62.3%) were postoperative wound infections. There was an increase in infection risk at low levels of HDL-C, and both low and high total cholesterol levels. After adjusting simultaneously for several confounders, including total cholesterol, low levels of HDL-C (< or = 20 mg/dL) yielded an odds ratio (OR) of 2.2 (95% confidence interval [CI95], 0.6-7.9) for SSI and an OR of 10.3 (CI95, 0.7-151.5) for RTI. Otherwise, no trend was observed between HDL-C levels and infection risk, and no increased risk of nosocomial infection was observed for HDL-C values in the range of 21 to 49 mg/dL. Serum cholesterol showed a U-shaped relationship with nosocomial infection risk. Both low levels (below 102 mg/dL) and high levels (above 290 mg/dL) of total cholesterol were associated with a higher risk of SSI (mainly those caused by gram-negative bacteria) and RTI in comparison with the reference group (139-261 mg/dL). CONCLUSIONS: Serum HDL-C and total cholesterol seem to be associated with the risk of nosocomial infection in surgical patients.

Nosocomial infections in surgical patients: comparison of two measures of intrinsic patient risk.

OBJECTIVE: To compare, in subjects undergoing general surgery, two measures of intrinsic patients risk for nosocomial infection: the Study on the Efficacy of Nosocomial Infection Control (SENIC) index and the National Nosocomial Infection Surveillance (NNIS) System index. DESIGN: Prospective cohort study, with follow-up for 1 month after hospital discharge. SETTING: The general surgery service of a tertiary hospital. MAIN OUTCOME MEASURE: Surgical-site infection. PATIENTS: 1,483 subjects aged 10 to 92 years. RESULTS: During follow-up, 155 patients developed nosocomial infection, yielding a cumulative incidence of 10.5%. The NNIS index showed a linear trend with both crude and adjusted (for SENIC index) rates of surgical-wound infection. The SENIC index did not exhibit any linear trend with adjusted (for NNIS index) rates of surgical-wound infection. To delineate whether the SENIC index added explanatory information to the NNIS index (or vice versa), we regressed each variable on the other. Logistic regression analyses confirmed the results of stratified analysis: residuals of the NNIS index added discriminating ability to the SENIC index, whereas residuals of the SENIC index did not improve the predictive power of the NNIS index. CONCLUSIONS: The NNIS index had a better ability than the SENIC index for discriminating and predicting risk of surgical-wound infection.

Surgical wound infections diagnosed after discharge from hospital: epidemiologic differences with in-hospital infections.

BACKGROUND: The purpose of this study was to study postoperative infections detected in hospital and after discharge and to identify risk factors for such infections. METHODS: A prospective cohort study was used, with follow-up of 30 days after hospital discharge, on 1483 patients admitted to the general surgery service of a tertiary care hospital. The main outcome measure was surgical wound infection (SWI). Relative risks, crude and multiple risk factors adjusted for by logistic regression analysis, and their 95% confidence intervals (CIs) were estimated. RESULTS: During follow-up 155 patients showed evidence of nosocomial infection, 134 in hospital and 21 at home, yielding a cumulative incidence of 10.5%. According to several variables (age, American Society of Anesthesiologists score, serum albumin, the SENIC and National Nosocomial Infections Surveillance indexes of intrinsic patient risk, length of hospital stay, etc.) there were no differences between patients with postdischarge SWI and uninfected patients; however, differences were detected between postdischarge SWI and in-hospital SWI, as well as between patients with in-hospital SWI and patients without infections. The analysis of risk factors showed that most predictors for in-hospital SWI did not behave in the same manner for postdischarge SWI. Stepwise logistic regression analysis identified cancer (odds ratio = 4.5, 95% CI = 1.7 to 12.2, p = 0.003) and surgeon performing the operation (for medium risk, OR = 4.4, 95% CI = 0.9 to 21.3, p = 0.059; for high risk, OR = 3.0, 95% CI = 0.7-13.3, p = 0.144) as independent risk factors for postdischarge SWI. CONCLUSIONS: There were important epidemiologic differences between in-hospital SWI and postdischarge SWI; most risk factors for in-hospital SWI are not predictors for postdischarge SWI.