Risk factors for surgical wound infection among the elderly.

One hundred fifty-seven elderly patients with surgical wound infection were matched on wound classification and date of surgery to non-infected control patients. Factors examined for their association with wound infection included medical history, functional status, behaviour (e.g. smoking), factors predisposing to infection (e.g. results of CBC and urinalysis) and operative factors such as preparation, duration and type of operation. Conditional logistic regression analysis identified factors already known to be risk factors for wound infection at all ages (e.g. type and duration of operation), as well as factors unique to the elderly (e.g. age greater than 70 years and limited mobility).

Sex-specific suicide trends in Canada, 1971-1985.

The present study analysed changes in sex-specific suicide rates in Canada from 1971 to 1985. A significant increase in the male-to-female ratio of suicide rates was observed. Our analysis of sex-specific age-adjusted rates revealed that this increasing ratio was a function of both increasing male rates and decreasing female rates, but that the latter was more marked. This divergence of male and female rates within the last decade and a half parallels similar changes noted both in the US and in the majority of European countries, but contrasts with a pattern of converging rates throughout North America and much of Europe prior to 1970.

A biomechanical study of suture pullout in linea alba.

The relationship of suture bite size, suture diameter, and fascial thickness to strength of wound closure was studied in cadaveric linea alba. All soft tissue was removed from the fascia of 12 abdominal walls that were cut into 346 test sections. A single suture loop was placed in each section, simulating laparotomy closure with interrupted technique. Suture bite size (0.3, 0.6, 0.9, 1.2, 1.5, and 1.8 cm) and gauge (00, 0, 1, and 2) were randomly assigned. The force and energy required to pull out suture loops were measured. Mean linea alba thickness was greater above the linea semicircularis than below (1.19 vs 0.77 mm; p less than 0.001). Similarly, mean pullout force was greater above the linea semicircularis (58.2 vs 31.6 N; p less than 0.001). Regression analysis found that fascial thickness and bite size accounted for 68% of observed variability in pullout force. Suture diameter was unrelated to pullout force. Optimum security was obtained with bites of at least 1.2 to 1.5 cm.

Expression pattern of metalloproteinases and their inhibitors changes with the progression of human sporadic colorectal neoplasia.

Several studies have implicated the extracellular matrix-degrading metalloproteinases (MMPs) as essential agents in tumor cell invasion and metastasis. In the present study, we have investigated the patterns of expression of a number of MMPs and their specific tissue inhibitors (TIMP-1 and TIMP-2) in human colonic tissue samples that represent various stages of progression from adenomas showing different degrees of dysplasia to adenocarcinomas. We assessed levels of mRNA by Northern blot analysis and the results were measured semiquantitatively by densitometry. In total, we analyzed nine adenomas of varying size and with varying degrees of dysplasia, three adenomas with adenocarcinoma (malignant polyps), and five adenocarcinomas. Although expression of MMP and TIMP mRNA was highly intercorrelated, transcripts for stromelysin 3 and TIMP-2 (high) showed the strongest relation to the neoplastic process. Detection of stromelysin 3 mRNA accompanied a diagnosis of severe dysplasia or malignancy, whereas levels of TIMP-2 (high) mRNA transcripts permitted finer distinctions on the neoplastic continuum. These data indicate changes within extracellular matrix acquired during the process of malignant transformation of human sporadic colorectal neoplasia.

Relationship between the clinical aggressiveness of large cell immunoblastic lymphomas and expression of 92 kDa gelatinase (type IV collagenase) and tissue inhibitor of metalloproteinases-1 (TIMP-1) RNAs.

Aberrant expression of secreted proteinases and their specific inhibitors is believed to represent an important factor in the pathogenesis of invasion and metastases of malignant neoplasms. Our previous data indicated a link between elevated expression of tissue inhibitor of metalloproteinases-1 (TIMP-1) and the clinical aggressiveness of malignant non-Hodgkin's lymphomas. Further studies are presented on eighteen cases of high grade, large cell immunoblastic lymphoma in which expression at the RNA level of TIMP-1 and the metalloproteinase, 92 kDa gelatinase, were analyzed. Factors that may influence production of 92 kDa gelatinase, such as necrosis, vascularity, proliferative activity, and extranodal extension, as well as clinical parameters, such as age and sex, stage, location, and survival were assessed. Statistical analysis showed that, although clinical stage was the most important predictor of survival, after controlling for age at diagnosis, levels of 92 kDa gelatinase transcripts added to the ability to predict survival.

Influence of level and depth on recurrence rate in thin melanomas.

A population-based study of the biology of the thin-level melanoma according to site, Breslow's thickness, and Clark's level was undertaken. Two hundred fifteen patients were studied with a mean follow-up of 41 months. Overall, 23 patients (10.7%) had recurrences, 8 locally, 9 regionally, and 6 systemically, despite an adequate local excision. A multivariate analysis was done. In the patients with thin lesions (less than 1 mm), increasing level (p < 0.002) and head and neck site (p < 0.04) increased the risk of recurrence. Increasing thickness of melanoma up to 1 mm did not influence the risk. This study identifies a group of high-risk melanoma patients for whom adjuvant therapy to decrease recurrences should be studied.

Linea alba closure: determination of ideal distance between sutures.

An experiment was conducted to determine the optimal distance between sutures in closure of abdominal midline incisions. Human cadaveric fascia was harvested soon after death and stored at -70 degrees C until testing. Suture pullout tests were performed to determine the maximal force applied to the fascia before pullout. Fascia from the opposite side of the same cadaver was used as a control. In a first series of testing, we observed that the pullout force of two sutures dropped linearly as they were brought closer than 12 mm apart. In a second series we observed no increase in pullout force using multiple sutures closer together compared to fewer sutures 15 mm apart. The experiments suggest that the mechanical requirements of closing a midline abdominal incision are met by placing sutures 10-15 mm apart.

Sex-specific trends in suicide method, Canada, 1971-1985.

Between 1971 and 1985, sex-specific suicide rates in Canada have diverged, with male rates increasing and female rates decreasing. Using linear regression techniques, we examined changes in sex- and method-specific rates and their association with changes in overall sex-specific rates. 92% of the variability in the overall female rates was explained by the declining rate for poisoning by solid or liquid substances. The most important change for males was the increasing rate for hanging, strangulation and suffocation which explained 65% of the change in the overall rate.

Injuries related to consumer products in Canada--a systematic literature review.

OBJECTIVES: To conduct a systematic literature review of injury related to certain consumer products. METHODS: Forty-six empirical research reports along with 32 surveillance reports from the Canadian Hospitals Injury Reporting and Prevention Program (CHIRPP) were examined to determine the approximate number of injuries associated with a given product per year and any trends in frequency. Percentages of injuries that: (1) resulted in hospitalization, (2) appeared to result from the product itself and (3) were associated with risky or inappropriate use and/or non-use of a helmet were also extracted from the reports. RESULTS: Outdoor play and sports equipment appear to be associated with the greatest numbers of injuries. A relatively high proportion of injuries appear to result from inappropriate or risky use of a product and/or inadequate safety precautions. CONCLUSION: This review identified the following areas of concern regarding consumer products and injuries: lack of helmet use by people using in-line skates, sleds, snowboards, downhill skis and personal-powered watercraft; operation of all-terrain vehicles (ATVs) and snowmobiles by alcohol-impaired people; operation of snowmobiles at excessive speeds; poor design of playground equipment; and unsafe storage and use of matches.

TITLE: Blessures associées à des produits de consommation au Canada : revue systématique de la littérature. OBJECTIFS: Effectuer une revue systématique de la littérature portant sur les blessures associées à certains produits de consommation. MÉTHODOLOGIE: Nous avons analysé 46 rapports de recherche de nature empirique et 32 rapports de surveillance du Système canadien hospitalier d'information et de recherche en prévention des traumatismes (SCHIRPT) dans le but de déterminer le nombre approximatif de blessures par année associées à chaque produit ainsi que toute tendance dans les fréquences. Nous avons également extrait des rapports les pourcentages des blessures qui ont donné lieu à une hospitalisation, qui semblaient résulter du produit lui-même et qui étaient associées à une utilisation inappropriée ou dangereuse ou à l'absence de casque. RÉSULTATS: Les équipements de sport et de jeu de plein air semblent être associés aux nombres de blessures les plus élevés. Une proportion relativement importante de blessures semble résulter d'une utilisation inappropriée ou dangereuse du produit et du non respect des mesures de sécurité requises. CONCLUSION: Cette revue a permis de relever plusieurs sujets de préoccupation à propos des blessures associées à des produits de consommation : absence de casque lors de l'utilisation de patins à roues alignées, de traîneau, de planche à neige, de skis alpins ou de motomarine; conduite d'un véhicule tout terrain (VTT) ou d'une motoneige avec facultés affaiblies par l'alcool; conduite d'une motoneige à une vitesse excessive; conception défectueuse de certains équipements de terrain de jeu; entreposage et utilisation non sécuritaires d'allumettes.

Cancer patients who refuse treatment.

The value of cancer treatment was assessed using a 'natural experiment' where patients who refused treatment served as no-treatment controls in a situation where withholding treatment to form a control group is unethical. Each cancer patient who refused treatment in Alberta, Canada between 1975 and 1988 was compared with five subjects who accepted treatment, matched on cancer site, age, number of cancers, and time period. Variables associated with treatment-refusal were included in Cox's proportional hazards model of survival, with death from cancer as the endpoint and deaths from other causes as censored observations. Treatment was refused at a rate of 7.5 per 1,000. One-third of patients who refused treatment had lung cancer and most had unstaged disease. Treatment refusal was associated with a difference in median survival of approximately nine months. Site-specific analyses showed a range of effects. Case fatality among the treated patients fell by approximately 10 percent during the 14-year study period. Even in advanced disease, treatment can result in improved survival. However, the results of this study must be interpreted with caution and cannot be generalized to all cancer patients.

Surgical wound infection and cancer among the elderly: a case control study.

Surgical wound infection occurs in fewer than 5% of operations. Nevertheless, it represents the second most common type of hospital-acquired infection and results in increased morbidity and mortality. As with all nosocomial infections, the rate of surgical wound infection increases with age. Patients over 65 years of age run an approximately 15% risk of surgical wound infection. Two-thirds of patients with invasive cancer other than non-melanotic skin cancer are aged 65 years and over. Over half of them are treated surgically for their cancer. Cancer and other chronic diseases have been cited as possible causes of the increased risk of nosocomial infection among the elderly. Using the Foothills Hospital Wound Study Data Base as the sampling frame, we conducted a case-control study of surgical wound infection and cancer among the elderly. Cancer was found not to be a risk factor for surgical wound infection. The results are discussed in relation to the role of immunity in both disorders.

The natural history of appendicitis in adults. A prospective study.

OBJECTIVE: The authors relate prehospital delay and in-hospital delay to the incidence of perforation of appendicitis. SUMMARY BACKGROUND DATA: Quality assurance studies use perforation rate as an index of quality of care. This is based on the assumption commonly presented in retrospective reports that in-hospital delay to surgery influences the incidence of perforation. Only one limited study prospectively found that prehospital delay increased the perforation rate. METHODS: During a 6-month period, 95 consecutive adults undergoing appendectomies at Foothills Hospital in Calgary, Alberta, were questioned as to onset and type of first symptom (i.e., epigastric discomfort, anorexia nervosa, vomiting, and abdominal pain). Time of emergency room (ER) arrival, surgery consultation, and operating room start were taken from the chart. Surgical and pathology reports were used to identify status of appendix (normal, inflamed, suppurative, gangrenous, perforated) and presence of abscess cavity. The status of appendix was related to prehospital and in-hospital delay to establish significance. RESULTS: There were 13 (14%) normal, 67 (70%) inflamed, and 15 (16%) perforated appendices. Patients with perforated appendices waited 2.5 times longer before reporting to the ER, compared with patients with inflamed appendices (57 hours vs. 22 hours, p < 0.007). Once in the hospital, patients with perforated appendices were identified and treated faster than those with inflamed appendices (7 vs. 9 hours, p < 0.039). Analysis by ER physician was 3 hours whether the appendix was normal, inflamed, or perforated. Analysis by the surgeon was significantly shorter in patients with perforated appendices than patients with inflamed appendices (4 vs. 6 hours, p < 0.039). CONCLUSIONS: This prospective study identifies that delay in presentation accounts for the majority of perforated appendices. Clinical evaluation is effective for identifying patients with more advanced disease. Indiscriminate appendectomy as an attempt to decrease perforation is not supported by these data. Hospital perforation rates likely reflect patient factors, illness attitude, and access to medical care.

Late results of cesarean and vaginal delivery in cases of breech presentation.

This study compared the subsequent development of children in breech presentation according to the method of their delivery - vaginal or cesarean section. No differences were found between children born vaginally and those born by cesarean section after some labour, except for a larger variability in the outcomes of the latter group. Only 4% of the deliveries were by cesarean section without labour, and when analysed separately the data for this group frequently showed the poorest outcome. Reasons for the observations are suggested, and proposed further research is outlined.

Perioperative cefazolin prophylaxis in hip fracture surgery.

Antibiotics given perioperatively are thought to decrease the occurrence of postoperative wound infection. The duration of treatment for hip fracture surgery is empirical. This randomized, double-blind, single-hospital clinical study was carried out to assess the effect of both antibiotic use and duration of use on wound infections in hip fracture surgery. Wound infection rates in three groups of patients were compared: those who received four doses of cefazolin (108 patients), those who received one dose of cefazolin and three doses of placebo (83 patients) and those who received four placebo doses (121 patients). Results showed an infection rate of 1.6% for the four-dose group, 2.4% for the one-dose group and 3.7% for the placebo group. These differences were not statistically significant, even when both treatment groups were combined and compared with the placebo group. The authors conclude that until more patients are added, empirical use of antibiotics should be continued in patients who undergo hip fracture surgery.

Predicting the outcome of exploratory laparotomy in ICU patients with sepsis or organ failure.

Critically ill patients with sepsis and/or organ failure are difficult to assess. They are often comatose or on steroids and many nonspecific findings such as fever, positive blood cultures, or septic shock which may suggest intra-abdominal sepsis are far from diagnostic. To determine whether decision making regarding the use of laparotomy in these patients could be improved upon, we reviewed our experience with consecutive intensive care unit patients who had laparotomy and we related laparotomy outcome to clinical signs and symptoms. Seventy-three per cent of the 100 laparotomies reviewed were positive for intra-abdominal sepsis. A discriminant function analysis revealed that eight factors in combination predicted laparotomy outcome. However, the overall accuracy of the discriminant function prediction (76.8%) offered little improvement over the policy in place for performing laparotomies in this group of patients at the participating hospitals during the time period of our investigation.

Frequency of hereditary nonpolyposis colorectal cancer in southern Alberta.

The frequency of hereditary nonpolyposis colorectal cancer was evaluated in a group of colorectal cancer patients under age 50 diagnosed in southern Alberta between 1973 and 1987. Families were identified as positive for this syndrome if three first-degree relatives in the kindred had colorectal cancer. Of the 390 patients with adenocarcinoma, 318 patients participated. The frequency of hereditary nonpolyposis colorectal cancer was 3.1% (12 families) in this group (Ci95 1.6-5.3%). Clinical characteristics reported on from the index patients include tumor location, Dukes stage at presentation, frequency of synchronous and metachronous tumors, frequency of second primaries, and survival. The 5- and 10-year actuarial survival was 86% and 69%, respectively.

Histologic staging in malignant melanoma: cross-sectional area revisited.

BACKGROUND AND OBJECTIVES: Tumor thickness is considered the single most important predictor of survival in clinically localized malignant melanoma. A recent study found tumor volume a more sensitive predictor of survival than thickness. Volume measurement, however, is complicated, time consuming, and based on biologically imprecise mathematical models of tumor configuration. This report compares the prognostic power of cross-sectional area (CSA), a simpler measurement than volume, with tumor thickness. METHODS: Forty-five patients with clinically localized malignant melanoma and a minimum 5-year follow-up post excision with negative resection margins were retrospectively followed for disease recurrence or death. Digitalized histologic images of each tumor were made from the original pathology slides and stored on a compact disc. Maximum tumor thickness and CSA were calculated for each primary melanoma using an image analysis program and compared for predictive accuracy of 5-year survival. RESULTS: CSA was positively correlated with maximum tumor thickness (r = 0.76). Both measures had a similar predictive accuracy for survival. Patients with melanomas less than 8 mm2 had superior 5-year (94%) and disease-free survival rates (78%) compared to patients with melanomas exceeding 8 mm2 (5-year survival, 62%; 5-year disease-free survival, 23%). CONCLUSIONS: CSA is an easily calculated measurement that is as predictive for 5-year survival as is Breslow's thickness. Prospective assessment of CSA is warranted.

Comparative analysis of the expression patterns of metalloproteinases and their inhibitors in breast neoplasia, sporadic colorectal neoplasia, pulmonary carcinomas and malignant non-Hodgkin's lymphomas in humans.

Matrix metalloproteinases (MMPs) and their inhibitors (tissue inhibitors of metalloproteinases, TIMPs) play essential roles in the remodelling of the extracellular matrix (ECM). Results of in vivo and in vitro studies suggest that the balance between MMPs and TIMPs is altered in neoplasia, contributing to the invasive and metastatic properties of malignant tumours. In this study we have analysed the expression of five MMP genes and TIMP-1 and TIMP-2 in 37 benign and malignant lesions of human breast using Northern blot analysis. MMP-9 (92 kDa gelatinase) and MMP-11 (stromelysin 3) were most consistently expressed by carcinomas. Based on detection of either MMP-9 or MMP-11 mRNAs, we were able to distinguish between malignant and benign disease with a predictive accuracy of 90% with 94% sensitivity and 85% specificity. Subsequently, these results were compared with results for carcinomas of colon and lung and malignant non-Hodgkin's lymphomas (NHL). Elevated MMP-9 and TIMP-1 expression was observed in all four systems. MMP-11 characterised all carcinomas as well as carcinomas in situ but was not detectable in NHL. Our data therefore argue that there are remarkably similar patterns of specific functions involved in ECM remodelling that correlate with malignancy in different human tumours of different histogenesis. However, MMP-11 expression is a characteristic of tumours of epithelial origin that is not found in lymphoid neoplasia. Thus it suggests that MMP-11 may play a regulatory role in the invasion and metastasis of carcinomas.