Diana Vilar-Compte

Surgical site infections at the National Cancer Institute in Mexico: A case-control study***

OBJECTIVES To quantify the surgical infection rate and to identify risk factors associated with surgical site infection. METHODS We conducted a case-control study of all surgical patients between January 1, 1993, and June 30, 1994. The frequency of surgical site infection per 100 surgeries was calculated. The odds ratio (OR) was estimated by using logistic regression analysis. SETTING A 130-bed tertiary-care teaching hospital for adult patients with cancer. RESULTS The study followed 3372 surgeries. Three hundred thirteen patients had a surgical site infection (rate per 100 surgeries: 9. 30). The risk factors associated with surgical site infection were diabetes mellitus (OR = 2.5, 95% confidence interval [CI] = 1.27-4. 91), obesity (OR = 1.76, 95% CI = 1.14-2.7), presence of surgical drains for >5 and <16 days (OR = 1.84, 95% CI = 1.02-3.31), and presence of surgical drains for >/=16 days (OR = 2.14, 95% CI = 1. 0-4.6). The bacteria most frequently isolated were Escherichia coli 38 (21.8% of the total of microorganisms found), Pseudomonas sp 22 (12.6%), Staphylococcus aureus 16 (9.2%), and coagulase-negative Staphylococcus 25 (13.6%). The coexistence of other nosocomial infections was greater among the cases (OR = 1.8, 95% CI = 1.1-3.1) than in the control group. CONCLUSIONS The surgical site infection rate in our hospital is slightly higher than the rates reported for general hospitals. The risk factors associated with surgical site infection are similar to those previously reported. Diabetes mellitus, obesity, and prolonged presence of a surgical drain increased the risk of infection.

Hyperglycemia as a risk factor for surgical site infections in patients undergoing mastectomy

BACKGROUND The aim of this study was to evaluate the association between perioperative hyperglycemia and surgical site infections (SSIs) in patients undergoing mastectomy. METHODS In this nested case-control study, patients undergoing mastectomy from May 2004 to June 2006, at the National Cancer Institute (INCan), Mexico, were included. Five blood glucose values were obtained for each patient. Patients were followed prospectively by direct observation for at least 30 days. RESULTS A total of 260 patients were included. Patient characteristics were similar in cases and controls. Cases were older (>50 years) (P = .001) and were more frequently treated with concomitant chemoradiation (P < .0001) than controls. Fifty cases (23.8%) developed an SSI. At least 1 measurement of blood glucose value > or = 150 mg/dL increased the risk for SSI (odds ratio [OR] = 3.05; 95% confidence interval [CI] = 1.5 to 6.3; P = .006). Variables associated with SSI after logistic regression analysis included age >50 years (OR = 3.7; 95% CI = 1.5 to 9.2; P = .005), preoperative concomitant chemoradiation treatment (OR = 2.8; 95% CI = 1.4 to 5.8, P = .0004), and any blood glucose value > or = 150 mg/dL (OR = 2.9, 95% CI = 1.2 to 6.2; P = .02). CONCLUSION Postoperative SSI was a very frequent complication in this cohort. Our data indicate that higher blood glucose values are an independent risk factor for postoperative SSI. Preoperative concomitant chemoradiation and age > 50 years were also risk factors for developing an SSI in patients undergoing mastectomy.

Surgical Site Infections in Breast Surgery: Case-control Study

The purpose of this study was to estimate the frequency of surgical site infections (SSIs) and identify associated risk factors for each type of breast surgery at a cancer hospital. We used a nested case-control design. Between February 1, 2000 and July 31, 2000, all breast surgeries performed were recorded on a daily basis. After hospital discharge, we evaluated patients simultaneously with surgeons three times a week for 30 days or longer. The odds ratio (OR) was estimated using logistic regression analysis. The study followed 280 patients (298 wounds). Altogether, 77 SSIs were detected, for an overall SSI rate of 25.8% (77/298). For excisions, conservative surgery, and radical mastectomies the SSI rates were 1.4%, 18.0%, and 38.3%, respectively. Excisions were excluded (n = 68) for risk factor analysis. After multivariate analysis, risk factors associated with SSIs were obesity [OR 2.5, 95% confidence interval (CI) 1.2–4.3], concomitant chemotherapy and radiation (OR 2.3, 95% CI 1.2–4.3), radical surgery (OR 3.1, 95% CI 1.1–8.6), insertion of a second drain during the late postoperative period (OR 3.7, 95% CI 1.8–7.8), and drainage duration ≥ 19 days (OR 2.9, 95% CI 1.5–5.6). The bacteria most frequently isolated were Pseudomonas aeruginosa (n = 18), Serratia sp. (n = 18), Staphylococcus aureus (n = 10), and Staphylococcus epidermidis (n = 10). Poor compliance with infection control practices and wound management was detected throughout the study period. The overall frequency of SSIs for mastectomies was higher than the reported rates, which was principally related to the more radical surgery required for advanced-stage disease, preoperative irradiation, and inadequate wound and drain care.

Randomized controlled trial of Hepatitis B virus vaccine in HIV-1-infected patients comparing two different doses.

BackgroundCo-infection with hepatitis B virus (HBV) and human immunodeficiency virus (HIV) is not infrequent as both share same route of exposure. The risk of developing chronic hepatitis B virus is 6%, in general population but can reach 10–20% in HBV/HIV co-infected patients. When compared to general population, the response rate to HBV vaccine in HIV-infected patients is diminished, so previous studies have tried to improve this response using variety of schedules, doses and co-administration of immunomodulators. The purpose of this study was to evaluate two doses of recombinant HBV vaccine (10 or 40 μg), IM at 0, 1 and 6 months. Vaccination response was measured 30–50 days after last dose; titers of >9.9 IU/L were considered positive.ResultsSeventy-nine patients were included, 48 patients (60.7%) serconverted. Thirty-nine patients (49.3%) received 10 μg vaccine dose, 24 patients (61.5%) seroconverted. Forty patients (50.7%) received 40 μg vaccine dose, 24 (60%) seroconverted. There were no differences between two doses. A statistically significant higher seroconversion rate was found for patients with CD4 cell counts at vaccination ≥ 200 cel/mm3 (33 of 38 patients, 86.8%), compared with those with CD4 < 200 cel/mm3 (15 of 41, 36.6%), [OR 11.44, 95% IC 3.67–35.59, p = 0.003], there were no differences between two vaccine doses. Using the logistic regression model, CD4 count <200 cel/mm3 were significantly associated with non serologic response (p = 0.003). None other variables such as gender, age, risk exposure for HIV, viral load, type or duration of HAART or AIDS-defining illness, were asociated with seroconversion.ConclusionIn this study, an increase dose of HBV vaccine did not show to increase the rate of response in HIV infected subjects. The only significant findings associated to the response rate was that a CD4 count ≥ 200 cel/mm3, we suggest this threshold at which HIV patients should be vaccinated.

Wound healing in radiated skin: pathophysiology and treatment options

Ulcers in radiated skin continue to be a challenge for health care practitioners. Healing impairment in the setting of radiation‐damaged tissue will most of the time lead to chronic wounds that reduce the patient’s quality of life. In this review, we present an update of the pathophysiology of tissue damage caused by radiation that leads to chronic ulceration. We also explore the evidence available on the different prevention and treatment modalities that have been reported in the literature. The evidence for most preventive measures is inconclusive; however, sucralfate and amifostine seem to be the adequate recommendations for prophylaxis. As for treatment of ulcerated patients, the strongest level of evidence found was for the use of pentoxifylline, but proper trials are still scarce to be considered standard adjuvant therapy. Hyperbaric oxygen, cytokines and other growth factors and surgical interventions have shown some benefit in case reports and case series only. Other therapies show promise based on their mechanism of action but need to be tested in human studies and clinical trials.

The impact of hospital-acquired infections with multidrug-resistant bacteria in an oncology intensive care unit

OBJECTIVE To describe overall site-specific hospital-acquired infection (HAI) rates and to describe the microbiological and antibiotic resistance profiles of infecting pathogens, together with their impact on multidrug-resistant (MDR) bacteria-associated mortality. METHODS We conducted a 5-year retrospective descriptive study of HAI in patients in the intensive care unit (ICU) of a cancer center in Mexico from January 2007 to December 2011. The following information was collected: patient characteristics and comorbidities, data related to the neoplasm and its treatment, microbiology, and the resistance pattern of all isolates. RESULTS During the study period, 1418 patients were admitted to the ICU; 134 of them developed 159 infections, with an incidence of 11.2/100 hospitalized patients and 32.2/per 1000 patient-days. Two hundred sixty-six microorganisms were isolated. The overall prevalence of MDR-HAI was 39.5%. The most frequent organisms were as follows: 54 (20%) Escherichia coli (94.4% of these were extended-spectrum beta-lactamase producers), 32 (12%) Staphylococcus aureus (90.6% of these were methicillin-resistant), 32 (12%) Enterococcus faecium (18.7% of these were vancomycin-resistant), and 20 (6%) Acinetobacter baumannii (all were MDR). Among patients admitted to the ICU, 252 (17.8%) died. Death was related to the HAI in 58 (23%) of these patients (p<0.001) and 51 (88%) had a MDR organism isolated (p=0.05). CONCLUSIONS The emergence of MDR bacteria poses a difficult task for physicians, who have limited therapeutic options. Critically ill cancer patients admitted to the ICU are at major risk of a bacterial MDR-HAI that will impact adversely on mortality.

Surveillance, control, and prevention of surgical site infections in breast cancer surgery: A 5-year experience

BACKGROUND We analyzed variations in surgical site infections (SSIs) during 5 years of a prospective surveillance program and investigated possible contributors to SSIs in a cohort of patients who underwent surgery for breast cancer. METHODS All breast surgeries performed between January 2001 and December 2005 were registered. Patients were followed-up by direct observation for at least 30 days under standardized conditions. The main outcome studied was SSI. A case-control analysis was conducted to identify SSI-associated risk factors and to evaluate SSI variations by means of a control chart. RESULTS During the study period, a total of 2338 breast cancer surgeries were recorded, and 441 SSIs (18.9%) were diagnosed. SSI frequency varied across the 5-year period, with a sharp decline seen after the introduction of preventive policies. After 2002, 3 out-of-confidence limits of SSIs were observed, 2 related to the use of evacuation systems and 1 associated with a group of rotating residents. Concomitant preoperative chemoradiation (odds ratio [OR]=3.47; 95% confidence interval [CI]=2.51 to 4.80), hematoma (OR=3.05; 95% CI=1.70 to 5.52), age > or = 58 years (OR=1.83; 95% CI=1.27 to 2.65), body mass index > or = 30.8 (OR=1.58; 95% CI=1.14 to 2.18), and duration of surgery > or = 160 minutes (OR=1.73; 95% CI=1.20 to 2.50) were found to be SSI-associated risk factors. CONCLUSIONS After 5 years of a continuous prospective surveillance program, we were able to decrease the rate of SSIs in patients undergoing breast cancer surgery (from 33.3% in 2000 to 18.9% in 2005), identify SSI-associated risk factors, and improve the quality of care delivered to these patients.

Surgical site infection (SSI) rates among patients who underwent mastectomy after the introduction of SSI prevention policies.

OBJECTIVE To describe the results of an intervention program to reduce the rate of surgical site infection (SSI) in the breast tumor department of a referral teaching hospital for patients with cancer. METHODS Preventive measures introduced in the Breast Tumor Department of the study hospital included the following: starting in July 2000, use of sterile technique for wound care; starting in 2001, use of closed antireflux silicone evacuation systems, use of perioperative antimicrobial prophylaxis, provision of feedback to surgeons, and remodeling of the ambulatory wound care clinic. We conducted surveillance of all patients who underwent mastectomy between February 1 and December 31, 2001, and the SSI rate was calculated. A case-control analysis was performed for risk factors known to be associated with SSI. Results were compared with the data from 2000. RESULTS The study included data on 385 surgeries. SSIs were registered in 52 (13.7%) of these 385, which was a rate 58.6% less than the 2000 infection rate (33.1%). Risk factors associated with SSI included concomitant chemotherapy and radiation therapy (OR, 3.6 [95% confidence interval {CI}, 1.9-7.1]), surgery performed during an evening shift (OR, 1.9 [95% CI, 1.1-3.6]), and insertion of a second drainage tube during the late postoperative period (OR, 2.8 [95% CI, 1.4-5.7]). The mean number (+/- SD) of postoperative visits to the outpatient wound care clinic was reduced from 11.6+/-7.1 in 2000 to 9.2+/-4.4 in 2001 (P<.001, Students t test). The mean number of days that the evacuation systems were used was reduced from 19.0 to 16.0 days (P=.001, Students t test). CONCLUSIONS Continuous wound surveillance, along with feedback to surgeons, use of closed antireflux evacuation systems, and standardized practices in wound and drainage-tube care, decreased by 58.6% the rate of SSI in a breast surgical department with high rates of infection.

Risk Factors for Extended Spectrum β-Lactamase-Producing Escherichia coli versus Susceptible E. coli in Surgical Site Infections among Cancer Patients in Mexico

BACKGROUND Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are of increasing concern as a cause of healthcare-associated infections. STUDY DESIGN Using a matched case-control design, demographics, antibiotic use, and relevant surgical data were obtained for 173 cases (ESBL E. coli surgical site infections, [SSI]) and 173 controls (antibiotic-susceptible E. coli SSI) in an oncology hospital in Mexico City. Conditional logistic regression modeling was used to calculate odds ratios (OR). RESULTS The mean age of patients was 53.6 years, 214 (62%) were female. Demographics and comorbidities were similar between groups. Although antibiotic prophylaxis was common among both cases and controls (84% and 89%), more than one-half of cases (53%) were given prophylaxis outside the recommended window or were exposed for more than 24 h in comparison to 29% of controls. Patients who received untimely (OR=3.13, 95% confidence interval [CI] 1.5-6.4) and discontinued inappropriately (OR 6.38, 95% CI=2.5-16.2) prophylaxis were more likely to develop an ESBL SSI. In addition, patients with an organ/space infection compared with superficial had a higher rate of a resistant infection (OR 4.2, 95% CI 1.3-13.9). Among patients not given timely or appropriately discontinued prophylaxis, post-operative cephalosporin use (OR 3.3, 95% CI 1.4-7.7) was associated with ESBL E. coli SSIs. CONCLUSIONS The appropriate timing and duration of perioperative antimicrobial prophylaxis were associated with lower risk of ESBL E. coli in SSIs. Even though compliance to antimicrobial prophylaxis guidelines is of the utmost importance, reduced exposure to cephalosporins may also potentially decrease the risk of ESBL SSI.

Changing Risk Factors for HIV Infection

BACKGROUND HIV infection in women is a growing problem in developing countries. Risk factors for HIV infection vary from country to country and may change with time. METHODS We describe a retrospective review of the epidemiologic characteristics and associated gynecologic diseases of all HIV-infected women seen at two tertiary-care hospitals in Mexico City. RESULTS One hundred thirty consecutive patients were included in the study from March 1985 to January 1996. Mean age at HIV diagnosis was 36.2 years (range: 16-76). Of the 75 women diagnosed with AIDS prior to 1992, 58 (69%) were infected through blood transfusion and 17 (20%) through sexual contact. After January 1992, 11 (23%) acquired infection through blood transfusion and 28 (60%) through sexual contact; these differences were statistically significant (p <0.0001). Prior to 1992, 66 (90%) women presented in stage IV, whereas after that year only 29 (51%) (p <0.001) presented in stage IV. Of 92 patients on whom a cervico-vaginal smear was carried out, human papillomavirus infection was identified in 22 (24%) women, nine (9.8%) had morphologic evidence of a cervical intraepithelial neoplasia (four with mild or moderate dysplasia and five with in situ cervical carcinoma). Four patients had invasive cervical carcinoma. CONCLUSIONS The main risk factor for HIV infection in Mexican women with AIDS changed from transfusion acquired to sexually acquired in 1992. As a country, we were successful in providing safe blood but failed to prevent sexual transmission. Our patients had a high frequency of cervical carcinoma and precursor lesions associated with human papilloma virus.