Richard W. Parsons

Association of sleep apnoea with myocardial infarction in men

To examine the hypothesis that sleep apnoea is a risk factor for ischaemic heart disease, overnight polysomnography was performed in 101 unselected male survivors of acute myocardial infarction (MI) aged less than 66 yr and in 53 male subjects of similar age without evidence of ischaemic heart disease. The apnoea index (AI, number of apnoea episodes per hour of sleep) was 6.9 (SEM 1.2) in the MI patients versus 1.4 (0.3) in the control subjects. After adjustment for age, body mass index, hypertension, smoking, and cholesterol level, multiple logistic regression analysis identified the top quartile of AI (greater than 5.3) as an independent predictor of MI patients. The relative risk for myocardial infarction between the highest and lowest quartiles of AI was 23.3 (95% confidence interval 3.9-139.9).

Epidural anaesthesia and analgesia and outcome of major surgery: a randomised trial

BACKGROUND Epidural block is widely used to manage major abdominal surgery and postoperative analgesia, but its risks and benefits are uncertain. We compared adverse outcomes in high-risk patients managed for major surgery with epidural block or alternative analgesic regimens with general anaesthesia in a multicentre randomised trial. METHODS 915 patients undergoing major abdominal surgery with one of nine defined comorbid states to identify high-risk status were randomly assigned intraoperative epidural anaesthesia and postoperative epidural analgesia for 72 h with general anaesthesia (site of epidural selected to provide optimum block) or control. The primary endpoint was death at 30 days or major postsurgical morbidity. Analysis by intention to treat involved 447 patients assigned epidural and 441 control. FINDINGS 255 patients (57.1%) in the epidural group and 268 (60.7%) in the control group had at least one morbidity endpoint or died (p=0.29). Mortality at 30 days was low in both groups (epidural 23 [5.1%], control 19 [4.3%], p=0.67). Only one of eight categories of morbid endpoints in individual systems (respiratory failure) occurred less frequently in patients managed with epidural techniques (23% vs 30%, p=0.02). Postoperative epidural analgesia was associated with lower pain scores during the first 3 postoperative days. There were no major adverse consequences of epidural-catheter insertion. INTERPRETATION Most adverse morbid outcomes in high-risk patients undergoing major abdominal surgery are not reduced by use of combined epidural and general anaesthesia and postoperative epidural analgesia. However, the improvement in analgesia, reduction in respiratory failure, and the low risk of serious adverse consequences suggest that many high-risk patients undergoing major intra-abdominal surgery will receive substantial benefit from combined general and epidural anaesthesia intraoperatively with continuing postoperative epidural analgesia.

Perioperative Epidural Analgesia and Outcome After Major Abdominal Surgery in High-Risk Patients

In a primary analysis of a large recently completed randomized trial in 915 high-risk patients undergoing major abdominal surgery, we found no difference in outcome between patients receiving perioperative epidural analgesia and those receiving IV opioids, apart from the incidence of respiratory failure. Therefore, we performed a selected number of predetermined subgroup analyses to identify specific types of patients who may have derived benefit from epidural analgesia. We found no difference in outcome between epidural and control groups in subgroups at increased risk of respiratory or cardiac complications or undergoing aortic surgery, nor in a subgroup with failed epidural block (all P > 0.05). There was a small reduction in the duration of postoperative ventilation (geometric mean [SD]: control group, 0.3 [6.5] h, versus epidural group, 0.2 [4.8] h; P = 0.048). No differences were found in length of stay in intensive care or in the hospital. There was no relationship between frequency of use of epidural analgesia in routine practice outside the trial and benefit from epidural analgesia in the trial. We found no evidence that perioperative epidural analgesia significantly influences major morbidity or mortality after major abdominal surgery.

TRENDS IN CIGARETTE SMOKING IN 36 POPULATIONS FROM THE EARLY 1980S TO THE MID-1990S: FINDINGS FROM THE WHO MONICA PROJECT

OBJECTIVES This report analyzes cigarette smoking over 10 years in populations in the World Health Organization (WHO) MONICA Project (to monitor trends and determinants of cardiovascular disease). METHODS Over 300,000 randomly selected subjects aged 25 to 64 years participated in surveys conducted in geographically defined populations. RESULTS For men, smoking prevalence decreased by more than 5% in 16 of the 36 study populations, remained static in most others, but increased in Beijing. Where prevalence decreased, this was largely due to higher proportions of never smokers in the younger age groups rather than to smokers quitting. Among women, smoking prevalence increased by more than 5% in 6 populations and decreased by more than 5% in 9 populations. For women, smoking tended to increase in populations with low prevalence and decrease in populations with higher prevalence; for men, the reverse pattern was observed. CONCLUSIONS These data illustrate the evolution of the smoking epidemic in populations and provide the basis for targeted public health interventions to support the WHO priority for tobacco control.

An audit of 267 consecutively excised mammographically detected breast lesions 1989-1993

Summary Pathology reports and slides were reviewed from 267 mammographically detected impalpable breast lesions, excised after hookwire localisation. There were 182 benign and 85 malignant lesions (benign to malignant ratio of 2.1:1). The invasive cancers tended to be small (mean 13 mm; 50% ≤ 10 mm), of low histologic grade (38% Grade I), with a low incidence of lymph node metastases (15%). A high proportion of pure duct carcinoma in situ (DCIS) lesions (21%) was found, and an unusually high proportion of invasive lobular carcinoma (17%). Preoperative fine needle aspiration (FNA) was performed in 95 (36%) cases, including 47 (18%) sampled using sterotactic guidance and 48 (18%) sampled by palpation. The absolute sensitivity of diagnosis of malignancy was 32% and 5% respectively. In 79% of carcinomas further operation was performed, for axillary clearance or re‐excision of incompletely excised tumor; this high rate was largely a result of a decision not to use frozen section diagnosis for impalpable lesions and because of the early stages of the development of preoperative needle diagnosis. 58% of invasive cancers, including seven of eight (87.5%) carcinomas with an extensive intraduct component (EIC + ve), and 72% of DCIS were incompletely excised at the first operation. Residual tumor was found in the re‐excisions in 26% of EIC ‐ ve invasive carcinomas, 71% of the EIC + ve cases and 56% of DCIS lesions. The malignant lesions had highly favourable prognostic indices. The need for concentration of experience with pre‐operative FNA was highlighted. Positive excision margins were a good predictor for residual malignancy, particularly for EIC + ve cases and for DCIS lesions.

Design of the Multicenter Australian Study of Epidural Anesthesia and Analgesia in Major Surgery: The MASTER Trial

The Multicenter Australian Study of Epidural Anesthesia and Analgesia in Major Surgery (The MASTER Trial) was designed to evaluate the possible benefit of epidural block in improving outcome in high-risk patients. The trial began in 1995 and is scheduled to reach the planned sample size of 900 during 2001. This paper describes the trial design and presents data comparing 455 patients randomized in 21 institutions in Australia, Hong Kong, and Malaysia, with 237 patients from the same hospitals who were eligible but not randomized. Nine categories of high-risk patients were defined as entry criteria for the trial. Protocols for ethical review, informed consent, randomization, clinical anesthesia and analgesia, and perioperative management were determined following extensive consultation with anesthesiologists throughout Australia. Clinical and research information was collected in participating hospitals by research staff who may not have been blind to allocation. Decisions about the presence or absence of endpoints were made primarily by a computer algorithm, supplemented by blinded clinical experts. Without unblinding the trial, comparison of eligibility criteria and incidence of endpoints between randomized and nonrandomized patients showed only small differences. We conclude that there is no strong evidence of important demographic or clinical differences between randomized and nonrandomized patients eligible for the MASTER Trial. Thus, the trial results are likely to be broadly generalizable.

Arrhythmias and mortality after myocardial infarction in diabetic patients: Relationship to diabetes treatment.

OBJECTIVE To assess the relationship between clinical course after acute myocardial infarction (AMI) and diabetes treatment. RESEARCH DESIGN AND METHODS Retrospective analysis of data from all patients aged 25–64 years admitted to hospitals in Perth, Australia, between 1985 and 1993 with AMI diagnosed according to the International Classification of Diseases (9th revision) criteria was conducted. Short- (28-day) and long-term survival and complications in diabetic and nondiabetic patients were compared. For diabetic patients, 28-day survival, dysrhythmias, heart block, and pulmonary edema were treated as outcomes, and factors related to each were assessed using multiple logistic regression. Diabetes treatment was added to the model to assess its significance. Long-term survival was compared by means of a Cox proportional hazards model. RESULTS Of 5,715 patients, 745 (12.9%) were diabetic. Mortality at 28 days was 12.0 and 28.1% for nondiabetic and diabetic patients, respectively (P < 0.001); there were no significant drug effects in the diabetic group. Ventricular fibrillation in diabetic patients taking glibenclamide (11.8%) was similar to that of nondiabetic patients (11.0%) but was lower than that for those patients taking either gliclazide (18.0%; 0.1 > P > 0.05) or insulin (22.8%; P < 0.05). There were no other treatment-related differences in acute complications. Long-term survival in diabetic patients was reduced in those taking digitalis and/or diuretics but type of diabetes treatment at discharge had no significant association with outcome. CONCLUSIONS These results do not suggest that ischemic heart disease should influence the choice of diabetes treatment regimen in general or of sulfonylurea drug in particular.

Early identification of patients at low risk of death after myocardial infarction and potentially suitable for early hospital discharge

Abstract Objectives: To find (a) whether data available shortly after admission for acute myocardial infarction can provide a reliable prognostic indicator of survival at 28 days, and (b) whether such an indicator might be used to identify patients at low risk of death and suitable for early discharge. Design: Retrospective analysis of data collected on patients admitted to a coronary care unit for acute myocardial infarction. A validation sample was selected at random from these patients. Setting: Coronary care units in Perth, Western Australia. Subjects: 6746 patients aged under 65 and resident in the Perth Statistical Division who during 1984-92 were admitted to a coronary care unit with symptoms of myocardial infarction. Main outcome measures: Sensitivity and specificity of several models for predicting survival at 28 days after myocardial infarction, and detailed performance characteristics of a particular model. Results: Patients with a pulse rate of 100 beats/min or less, aged 60 or under, and with symptoms typical of myocardial infarction, no past history of myocardial infarction or diabetes, and no significant Q wave in the admission electrocardiogram had a very high chance of survival at 28 days (99.2%). These patients made up one third of all patients studied. Conclusion: The prognostic index identifies patients very soon after admission who are at low risk of death and potentially eligible for early discharge from hospital or the coronary care unit. Computing the index does not need complex cardiac investigations.

Breast cancer in Western Australia in 1989: IV. summary of histopathological assessment in 655 cases

&NA; This study was part of a population‐based survey of all cases of breast cancer diagnosed in Western Australia in 1989. The paper concerns histopathology reporting by pathologists in 655 cases of carcinoma of the breast in that year, before the introduction of mammographic screening programmes. Pathological features of the neoplasms are documented, and the extent to which information known to be of clinical or prognostic importance was included in the reports is analysed. 96.5% of all pathology reports included information on breast cancer subtype and, in 98.6% of cases with axillary dissection, the number of lymph nodes dissected, and the number containing metastatic tumor was stated. In 83.7% of cases of invasive carcinoma exact tumor dimensions were recorded. In 44.9% of cases histological grade was recorded, and information about excision margins was present in 60% of reports overall. The reporting of pathological features in many instances was limited by the way in which the specimen was handled prior to reception. At the time of the study, views about the importance of many aspects of histological assessment were still evolving. Even now, for example, consensus is still being reached on the value of histological grading in predicting prognosis and whether reliable histological assessment of such factors as extent of DCIS and completeness of excision of DCIS is possible. The introduction of mammographic screening since 1989 has provided a focus for wider discussion about the value of histological information in prognostication and patient management. A case is made to support the use of “check lists” for surgical pathology reports in cases of breast cancer.

Copper-free nanocrystalline soft magnetic materials with high saturation magnetization comparable to that of Si steel

The effect of rapid annealing on the structural and magnetic properties of melt-spun Fe-B based alloys has been investigated. The grain size of a Fe85B13Ni2 alloy after primary crystallization is reduced significantly by rapid annealing, and a low coercivity of 4.6 A/m and a high saturation magnetization of 1.90 T are obtained. This saturation magnetization is comparable to those of Si steels (1.8–2 T). The core losses of nanocrystalline Fe85B13Ni2 are lower by 60%–80% as compared with those of commercial Si steels. Rapid annealing is found to be effective in realizing a magnetically soft nanostructure without Cu addition, leading to an exceptionally low content of nonmagnetic additives (2.8 wt. %) and thus a high saturation magnetization in the nanostructure.