A review of the management of small bowel obstruction. Members of the Surgical and Clinical Adhesions Research Study (SCAR)

Small bowel obstruction is a significant surgical problem and is commonly caused by postoperative adhesions. Patients suffering from this condition are often difficult to assess and require careful evaluation and management. Articles regarding the diagnosis, evaluation and management of small bowel obstruction have been identified from the Ovid, Embase and Silver Platter electronic databases and then reviewed by the authors. Particular emphasis has been placed on randomised controlled trials or large prospective series. Anecdotal reports or those containing small numbers have been largely excluded, but where they have been included it has been made clear in the text. The management of small bowel obstruction is predominantly the management of obstruction due to postoperative adhesions. The selective use of radiological techniques, such as water soluble contrast and CT studies, often help to characterise the nature of the obstruction and may even help with its resolution. Techniques involving the use of laparoscopy and barrier membranes may reduce morbidity but there is a need to evaluate these strategies further with prospective clinical trials.

Germicidal ultraviolet irradiation in air conditioning systems: effect on office worker health and wellbeing: a pilot study

OBJECTIVES

The indoor environment of modern office buildings represents a new ecosystem that has been created totally by humans. Bacteria and fungi may contaminate this indoor environment, including the ventilation systems themselves, which in turn may result in adverse health effects. The objectives of this study were to test whether installation and operation of germicidal ultraviolet (GUV) lights in central ventilation systems would be feasible, without adverse effects, undetected by building occupants, and effective in eliminating microbial contamination.

METHODS

GUV lights were installed in the ventilation systems serving three floors of an office building, and were turned on and off during a total of four alternating 3 week blocks. Workers reported their environmental satisfaction, symptoms, as well as sickness absence, without knowledge of whether GUV lights were on or off. The indoor environment was measured in detail including airborne and surface bacteria and fungi.

RESULTS

Airborne bacteria and fungi were not significantly different whether GUV lights were on or off, but were virtually eliminated from the surfaces of the ventilation system after 3 weeks of operation of GUV light. Of the other environmental variables measured, only total airborne particulates were significantly different under the two experimental conditions--higher with GUV lights on than off. Of 113 eligible workers, 104 (87%) participated; their environmental satisfaction ratings were not different whether GUV lights were on or off. Headache, difficulty concentrating, and eye irritation occurred less often with GUV lights on whereas skin rash or irritation was more common. Overall, the average number of work related symptoms reported was 1.1 with GUV lights off compared with 0.9 with GUV lights on.

CONCLUSION

Installation and operation of GUV lights in central heating, ventilation and air conditioning systems of office buildings is feasible, cannot be detected by workers, and does not seem to result in any adverse effects.

Adhesion-related hospital readmissions after abdominal and pelvic surgery: a retrospective cohort study

BACKGROUND

Adhesions after abdominal and pelvic surgery are important complications, although their basic epidemiology is unclear. We investigated the frequency of such complications in the general population to provide a basis for the targeting and assessment of new adhesion-prevention measures.

METHODS

We used validated data from the Scottish National Health Service medical record linkage database to identify patients undergoing open abdominal or pelvic surgery in 1986, who had no record of such surgery in the preceding 5 years. Patients were followed up for 10 years and subsequent readmissions were reviewed and outcomes classified by the degree of adhesion. We also assessed the rate of adhesion-related admissions in 1994 for the population of 5 million people.

FINDINGS

1209 (5.7%) of all readmissions (21,347) were classified as being directly related to adhesions, with 1169 (3.8%) managed operatively. Overall, 34.6% of the 29,790 patients who underwent open abdominal or pelvic surgery in 1986 were readmitted a mean of 2.1 times over 10 years for a disorder directly or possibly related to adhesions, or for abdominal or pelvic surgery that could be potentially complicated by adhesions. 22.1% of all outcome readmissions occurred in the first year after initial surgery, but readmissions continued steadily throughout the 10-year period. In 1994, 4199 admissions were directly related to adhesions.

INTERPRETATION

Postoperative adhesions have important consequences to patients, surgeons, and the health system. Surgical procedures with a high risk of adhesion-related complications need to be identified and adhesion prevention carefully assessed.

Laparoscopic exploration of the common bile duct: beyond the learning curve

BACKGROUND

Bile duct clearance at open cholecystectomy had become normal surgical practice before the introduction of laparoscopic cholecystectomy. However, perceived technical difficulties have deterred many surgeons from treating common bile duct stones at the time of laparoscopic cholecystectomy. This has led to a reliance on preoperative clearance of ducts known to have stones and postoperative clearance of ducts found to have stones at operation or those that subsequently develop complications of retained stones.

METHODS

The authors describe a series of 120 consecutive bile duct explorations carried out between April 1991 and February 1997 in a series of 1,237 laparoscopic cholecystectomies.

RESULTS

Laparoscopic exploration and clearance of the bile ducts was achieved in 89% of cases in the whole series, and 97% success was attained in the last 60 cases, which also were associated with a decrease in operating time.

CONCLUSIONS

We believe that for surgeons familiar with open common bile duct exploration and laparoscopic cholecystectomy, the next logical step is laparoscopic exploration of the common bile duct at the time of cholecystectomy, which is safe and readily mastered.

Heterogeneous antibody responses in tuberculosis

Antibody responses during tuberculosis were analyzed by an enzyme-linked immunosorbent assay with a panel of 10 protein antigens of Mycobacterium tuberculosis. It was shown that serum immunoglobulin G antibodies were produced against a variety of M. tuberculosis antigens and that the vast majority of sera from tuberculosis patients contained antibodies against one or more M. tuberculosis antigens. The number and the species of serologically reactive antigens varied greatly from individual to individual. In a given serum, the level of specific antibodies also varied with the antigen irrespective of the total number of antigens recognized by that particular serum. These findings indicate that person-to-person heterogeneity of antigen recognition, rather than recognition of particular antigens, is a key attribute of the antibody response in tuberculosis.

Evaluation of the monoclonal antibody antithyroperoxidase MoAb47 in the diagnostic decision of cold thyroid nodules by fine-needle aspiration

Fine needle aspiration (FNA) of cold thyroid nodules has become the first line diagnostic decision for electing which patients need surgery. In order to improve FNA accuracy, the monoclonal antithyroperoxidase (TPO) antibody (MoAb47) was tested. A total of 554 patients were included in this study and among them, 208 were referred to surgery. The results of FNA compared to the final histological diagnosis revealed a sensitivity and a specificity of 94 and 55% respectively, while the sensitivity and specificity of TPO immunodetection on the same cases reached 98 and 83% respectively. By combining the two methods, the 3 false-negative of FNA and 60% of suspicious cytology corresponding to histological benign lesions were correctly identified by immunocytochemistry. With better results than FNA alone, TPO immunodetection with MoAb47 represents a useful adjunct to conventional cytology for selecting patients for surgery.

[Anatomo-clinical prognostic factors of papillary carcinoma of the thyroid. Multivariate analysis: report of a series of 52 cases]

A retrospective study about 52 cases of papillary thyroid carcinomas was carried out with emphasis on histopathological features. The mean follow up period was 10 years. The survival curves were estimated using the Kaplan-Meier method and compared using the log rank test. The multivariate analysis was performed using the Cox's regression model. In univariate analysis, age, Tp (histopathological extension of the tumor), histological differentiation, VAN score (Vascular invasion nuclear Atypia tumor Necrosis) of Akslen and the LeuM1 expression were significant prognostic factors. In multivariate analysis, the Tp and histological differentiation were associated with high risks of poor outcome.

Aeroallergens and work-related respiratory symptoms among office workers

OBJECTIVE

We sought to determine the association between office workers' respiratory tract symptoms and immediate skin test reactions with exposure to fungal and house dust mite aeroallergens at their work sites.

METHODS

An initial prevalence survey was conducted among 1102 full-time workers in six mechanically ventilated, air-conditioned, nonindustrial buildings in downtown Montreal. Detailed environmental measures of 214 subjects' work sites were determined. Half of the workers reported frequent work-related respiratory tract symptoms on the initial survey. Participants simultaneously underwent allergy skin prick testing and completed a second self-administered questionnaire.

RESULTS

Contaminant levels were low and not associated with symptoms in the great majority of workers. For approximately 17% of workers, symptoms were associated with exposure to total concentrations of house dust mite allergen greater than 1 microg/gm floor dust (odds ratio [OR], 5.0; 95% confidence interval [CI], 1.3, 19.5]) or to detectable airborne Alternaria allergens in their offices (OR, 3.3; 95% CI, 1.2, 9.4 and in the ventilation system supplying their offices (OR, 3.9; 95% CI, 1.6, 9.6). Workers with positive skin test reactions to Alternaria extract were exposed at their work site to airborne Alternaria allergen (OR, 4.4; 95% CI, 1.4, 14.5) and cited significantly more respiratory symptoms on both questionnaires. Detection of airborne Alternaria allergen at work sites was significantly associated with detection in the ventilation system (OR, 4.0; 95% CI, 1.4,10.9); this was in turn associated with lower efficiency filters.

CONCLUSIONS

Potentially avoidable exposure to aeroallergens accounted for symptoms in a small subgroup of office workers with frequent work-related respiratory tract symptoms.

Impact of immigration on tuberculosis infection among Canadian-born schoolchildren and young adults in Montreal

We conducted a cross-sectional tuberculin survey among non-BCG-vaccinated Canadian-born schoolchildren in grades 6 and 10, health professional students, and young adult workers, to estimate the association of tuberculin reactions with indices of contact with tuberculosis. Participants underwent simultaneous tuberculin testing with PPD-T (standard) and PPD-B (from M. intracellulare). Exposure was estimated from questionnaire responses, group, aggregate census, and tuberculosis incidence data. Of 3,710 participants, 88 (2.4%) had positive tuberculin reactions, i.e., of 10+ mm. Positive tuberculin reactions were rarely associated with larger reactions to PPD-B, but were associated with older age (adjusted odds ratio for each 5 years: 1.5 [95% confidence interval, 1.3, 1.8]), household contact (4.2 [1.4, 12.7]), and population group (health professional versus all others: 0.6 [0.3, 1.0]). Estimated annual risk of infection declined by 3% per year. Tuberculin reactions were not associated with any indices of contact in school, work or neighborhood settings with foreign-born from tuberculosis endemic areas, nor with tuberculosis in Canadian-born. There was no evidence of transmission of tuberculosis from affected high risk sub-groups in Montreal to the general population working or attending school.

Issues in the management of contacts of patients with active pulmonary tuberculosis

The evidence regarding the transmission of tuberculosis and risk of infection and disease in several specific clinical situations has been reviewed. There is considerable epidemiologic evidence that contagiousness is not an all-or-nothing phenomenon and is affected by several factors, only one of which is the bacteriologic status of the patient's sputum. Although untreated smear negative, culture positive patients are less contagious on average, they still may transmit infection to their close and casual contacts. Compared with contacts with tuberculin conversion, persons who are already tuberculin positive have much lower risk of developing active tuberculosis after exposure, and persons with prior BCG vaccination are at somewhat lower risk. Preventive therapy will be of less benefit, but should still be recommended for contacts who are heavily exposed or are immune compromised. Epidemiologic studies using RFLP techniques could provide more precise answers to the questions in this review.

Effect of a new ventilation system on health and well-being of office workers

Sick building syndrome is the term given to a heterogeneous constellation of symptoms that affects workers in modern mechanically ventilated office buildings. Although the cause is unknown, there is evidence that the local environment of the work station is an important determinant of symptoms. In this study, investigators examined the effect of a new, individually controlled ventilation system on workers' symptoms. Investigators studied two groups of workers in one mechanically ventilated office building: (1) a control group at whose worksite no intervention was made and (2) an intervention group. The intervention consisted of installation of a device that allowed each worker control over the ventilation supplied to his or her worksite. Just before, and 4 and 16 mo after installation of this device, workers completed self-administered questionnaires regarding occurrence of symptoms. The new ventilation system resulted in higher air velocities, more variable temperatures, and higher concentrations of airborne dust and fungal spores. Four months after installation, workers with the new ventilation system reported fewer symptoms that were (a) work-related (p < .05) and that were work-related and frequent (p < .05); in addition, they reported fewer symptoms that reduced their capacity to work (p < .01). Sixteen months after installation, workers with the new device reported fewer symptoms than at baseline (although not as significantly), and they indicated that the indoor air quality improved their productivity by 11%, compared with a 4% reduction of productivity among the control group of workers (p < .001). Investigators concluded that the new ventilation system, which provided the workers with individual control over ventilation, was associated with important and sustained reduction in symptoms.

Effect of treatment on contagiousness of patients with active pulmonary tuberculosis

In view of the important consequences with regard to policies for respiratory isolation of hospitalized patients with active tuberculosis, the duration of contagiousness after initiation of effective therapy was reviewed. All relevant English-language literature was reviewed to identify in vitro, animal experimental, and epidemiological evidence regarding contagiousness of patients with active tuberculosis after initiation of therapy. Based on in vitro evidence of numbers of tubercle bacilli initially present and rapidity of reduction-with therapy, it can be predicted that patients whose respiratory secretions are initially smear-negative but culture-positive should no longer have viable bacilli detectable by culture within 2 weeks. Based on the same evidence, it can be predicted that, after 2 weeks of therapy, almost all smear-positive patients will remain culture-positive, and more than one half will remain smear-positive. There are few epidemiological studies of this issue, most of which have had major methodological weaknesses. None of the results from these studies can be considered relevant to the hospital environment, where the majority of workers are uninfected and patients are potentially immunocompromised. Animal and in vitro evidence suggest that patients with active tuberculosis remain contagious at least 2 weeks after the initiation of therapy. Patients with smear-positive disease are likely to be contagious much longer. There is no relevant and valid epidemiological evidence regarding this issue.

Prevalence of tuberculin skin test reactions among prison workers

OBJECTIVE

To determine the prevalence of positive tuberculin skin test (TST) reactions (10 mm or greater) among full-time employees of a provincial prison for women in Montreal.

METHODS

Participants underwent tuberculin skin testing and completed a self-administered questionnaire.

RESULTS

Among 129 employees identified, 118 (91%) underwent tuberculin testing. Among 102 born in Quebec who completed the questionnaire, 33 (32%) had positive TST reactions, including 12 (23%) of 52 subjects who had never been vaccinated. Positive TST reactions were significantly associated in multivariate analysis with BCG vaccination after infancy (OR = 4.5, 95% CI = 1.5-13.5), years of work at other provincial prisons (OR = 2.5 for each 5 years of work, 95% CI = 1.2-5.2), travel to tuberculosis endemic countries (OR = 7.7, 95% CI = 1.4-43), although not with work in the prison for women (OR = 1.3, 95% CI = 0.9-1.9)

CONCLUSION

The prevalence of positive TST reactions was greater among workers at a provincial prison for women than among a sample of students, suggesting increased occupational risk of tuberculosis infection.

Issues in the management of contacts of patients with active pulmonary tuberculosis

The evidence regarding the transmission of tuberculosis and risk of infection and disease in several specific clinical situations has been reviewed. There is considerable epidemiologic evidence that contagiousness is not an all-or-nothing phenomenon and is affected by several factors, only one of which is the bacteriologic status of the patient's sputum. Although untreated smear negative, culture positive patients are less contagious on average, they still may transmit infection to their close and casual contacts. Compared with contacts with tuberculin conversion, persons who are already tuberculin positive have much lower risk of developing active tuberculosis after exposure, and persons with prior BCG vaccination are at somewhat lower risk. Preventive therapy will be of less benefit, but should still be recommended for contacts who are heavily exposed or are immune compromised. Epidemiologic studies using RFLP techniques could provide more precise answers to the questions in this review.

IFN-gamma and IL-12 are increased in active compared with inactive tuberculosis

Cytokine-mediated immune responses to Mycobacterium tuberculosis infection are important determinants of M. tuberculosis disease development and pathology. However, the distinction between changes in cytokine profile attributable to M. tuberculosis infection and those associated with active pulmonary tuberculosis is unclear. We have compared T cells and their subsets, macrophages, and cytokine messenger RNA (mRNA) profile in the bronchoalveolar lavage (BAL) of patients with active pulmonary tuberculosis with inactive tuberculosis subjects. Ten patients with microbiologically confirmed active pulmonary tuberculosis and 25 subjects with inactive tuberculosis were recruited. Bronchoscopy with BAL was undertaken in all cases and BAL cytospins were examined using the techniques of immunocytochemistry and in situ hybridization. There was a significant increase in the percentage of BAL cells that were CD8+ T cells in active tuberculosis compared with inactive tuberculosis (mean +/- SEM: 7.2 +/- 0.9 versus 2.1 +/- 0.4, p < 0.001), but not CD3+ or CD4+ T cells nor macrophages. There were significant increases in the percentage of BAL cells expressing mRNA for interferon-gamma (IFN-gamma) and interleukin-12 (IL-12) in active versus inactive pulmonary tuberculosis subjects (8.0 +/- 0.6 versus 3.7 +/- 0.4 and 28.4 +/- 2.3 versus 10.2 +/- 1.0, p < 0.001, respectively). There were no significant differences between the active and inactive groups in the number of cells expressing mRNA for IL-2, tumor necrosis factor-alpha (TNF-alpha), IL-4, and IL-5. In conclusion, active pulmonary tuberculosis is associated with increased numbers of CD8+ cells and marked increases in the expression of IL-12 and IFN-gamma mRNA in the BAL, both of which may be useful markers of disease activity.

Tuberculosis infection among health care workers in Montreal

We conducted a cross-sectional survey to estimate the prevalence of tuberculosis infection among health care workers at two downtown Montreal hospitals. Participants completed questionnaires, then underwent two-step tuberculin testing. Records of previous tuberculin tests and BCG vaccinations were reviewed. Charts of all tuberculosis patients admitted in 1992-93 were also reviewed. Air changes and direction of air flow in patient care areas were measured using tracer gas techniques and smoke tubes. Of 619 eligible workers, 522 participated (84%). 196 (38%) were tuberculin reactors; 23 (4%) had documented conversions. Inadequate ventilation and delays in diagnosis were identified at both hospitals. Comparing clinical with nonclinical personnel, the adjusted odds of a significant initial tuberculin reaction were 2.6 (95% confidence interval 1.3, 5.2), of a documented conversion 13.6 (1.4, 132), and of a booster reaction 0.9 (0.2, 3.6). Initial tuberculin reactivity was associated with male gender (p = 0.008), BCG vaccination (p = 0.0001), foreign birth (p = 0.007), age (p < 0.0001), and occupation (p = 0.02); conversion with male gender (p = 0.001) and occupation (p = 0.01); and boosting with older age (p = 0.02) and BCG vaccination (p = 0.001). Among clinical personnel at two hospitals, the prevalence of significant tuberculin reactions and of documented conversions was unexpectedly high.

Patient characteristics associated with failure of tuberculosis prevention

OBJECTIVES

The cost-effectiveness of tuberculin screening may be substantially reduced by non-compliance of patients and physicians. We have examined the association of these problems with the socio-demographic characteristics of tuberculin reactors.

METHODS

Community-based tuberculin screening was conducted among students in grades 6 and 10, and in post-secondary health training, as well as young adult workers. A follow-up survey was conducted to determine if tuberculin reactors referred for further evaluation actually reported, if they were prescribed therapy when indicated, and if they took therapy when it was prescribed. Association of reactors' socio-demographic characteristics with these outcomes was analyzed.

RESULTS

Canadian-born subjects were less likely to report if they were: older (adjusted and standardized odds ratio: 0.7, 95% confidence interval: [0.5, 0.9]), resident in more affluent neighbourhoods (0.7 [0.6, 0.99]), and from single parent households (0.1 [0, 0.9]). Even when indicated, physicians were less likely to prescribe treatment for Canadian-born subjects who reported bacille Calmette-Guérin vaccination, but had not actually received this (0.3 [0.1, 0.7]), or who were from single-parent households (0.1 [0, 0.9]). Physicians were less likely to prescribe treatment for foreign-born who gave a history of BCG vaccination (0.1 [0.1, 0.3]), and were more likely to prescribe treatment for reactors from countries such as Haiti or Vietnam. The only factor significantly associated with compliance was that older Canadian-born subjects were less compliant (0.6 [0.4, 0.97]).

CONCLUSIONS

Failure to report for further medical evaluation and physician non-compliance were associated with a number of socio-demographic characteristics, and substantially reduced the benefit of a tuberculosis screening program.

Laparoscopic repair of perforated duodenal ulcers with a falciform ligament patch

Six patients are reported who presented with perforated duodenal ulcers. These were repaired laparoscopically by suturing the falciform ligament over the perforated ulcer. There were no complications and patients were discharged between 3 and 5 days after surgery. This technique is simpler to perform than a laparoscopic omental patch repair.