An evaluation of the autopsy following death in a level IV neonatal intensive care unit

OBJECTIVE

To ascertain the determinants of neonatal autopsy, define clinical errors in the causes of death, and elucidate the possible audit and genetic value of the autopsy following death in a Level IV neonatal intensive care unit (NICU).

METHODS

A review and correlation of clinical and autopsy information in a case series of infants who died during the period 1991-97.

RESULTS

Two hundred and twenty-nine of 4057 infants admitted to the NICU died and 91 (39.7%) underwent an autopsy. The underlying cause of death was significantly different in infants who had an autopsy compared with infants who did not (P = 0.02). The autopsy rate was higher for deaths from miscellaneous causes (52.9%), lethal malformation (46.8%) and infection (45.4%) than deaths from prematurity (25.9%) and asphyxia (19%). Clinical errors in the causes of death were found in 22% of the infants, and in 4.4% a change in management may have been curative or prolonged life. The autopsy had audit value in 26% of infants and genetic value for a single gene (Mendelian) disorder in 4.4%.

CONCLUSIONS

Although the autopsy following death in a Level IV NICU yields potentially useful information in more than one-third of cases, this does not seem sufficient to ensure a high neonatal autopsy rate.

Cortical evoked responses following esophageal balloon distension and electrical stimulation in healthy volunteers

Recording of evoked potential responses represents an objective and quantifiable method to study visceral afferent sensory pathways in humans. We examined the evoked responses to mechanical distension (balloon) and electrical stimulation of the proximal and distal esophagus. A standard manometric catheter with a latex balloon and an additional electrode attached to its body was placed in the lower esophagus in 15 healthy young volunteers. Repeated nonpainful balloon distension stimuli above the individual sensation threshold (0.17 Hz, 12-20 ml) or short electrical impulses (0.2 Hz, 12-16 mA) were delivered in an alternate fashion at 23 and 33 cm from the nares. Evoked potential responses (EP) were recorded through 22 scalp surface electrodes using the standard 10/20 International EEG system of electrode placement. Balloon distension produced a reproducible triphasic response at both sites. Peak latencies of three negative EP peaks were 92+/-17, 229+/-40, and 339+/-36 msec with proximal stimulation versus 154+/-24, 275+/-24, and 384+/-30 msec obtained with distal stimulation (P < 0.001). Electrical stimulation produced a triphasic response with significantly shorter peak latencies at both sites when compared to mechanical stimulation (P < 0.001). Peak latencies were 74+/-12, 137+/-11, and 245+/-27 msec proximal versus 83+/-12, 148+/-32, and 247+/-51 msec with distal stimulation (P < 0.01). The calculated conduction velocities for both modes of stimulation (balloon: 1.73+/-0.9 m/sec vs electrical: 10.1+/-3.4 m/sec) are compatible with conduction through C fibers and Adelta fibers, respectively. Both modes of stimulation produce characteristic brain responses that are conveyed through different types of afferent fibers. The respective contributions of both types of fibers to esophageal function and symptomatology can be specifically addressed using this approach in both normal and pathologic conditions.

Antagonism of ketamine-induced anesthesia by an inhibitor of nitric oxide synthesis: a pharmacokinetic explanation

Because ketamine is an antagonist of NMDA receptors, and because some NMDA receptors activate nitric oxide synthesis in brain, this study examined if nitric oxide synthase (NOS) inhibition by L-NAME altered the course of ketamine-induced behavioral impairment. Rats given progressive doses of L-NAME until NOS activity was inhibited at least 90% displayed reduced depth and duration of behavioral depression after i.m. ketamine. Blood and brain concentrations of ketamine, norketamine, and its dehydrogenated derivative were isolated from rats previously given saline or L-NAME as above, by ether extraction, HPLC separation, and ultraviolet quantitation. The same doses of L-NAME that altered ketamine behavior reduced blood and brain ketamine concentrations 15 min after administration to about three-fourths and one-third of control, respectively. The content of norketamine and its adventitial extraction product were similarly reduced relative to control but the ratio of metabolites to ketamine was not significantly altered (p > 0.05) in brain. The decreased delivery of ketamine into brain, perhaps due to L-NAME-induced alterations in blood flow, may explain the reduced behavioral response to ketamine in these rats.

Overview of olestra: a new fat substitute

Olestra is a mixture of hexa-, hepta- and octa-esters formed from the reaction of sucrase and long chain fatty acids isolated from edible oils. Olestra has properties similar to those of traditional triglycerides but is not hydrolyzed by pancreatic lipases and, therefore, serves as a noncaloric replacement for fats in the diet. The safety of olestra has been established in over 100 studies in seven different species of animals, with confirmatory safety data coming from approximately 75 human studies; consumption of olestra at levels typical for savoury snacks does not result in reports of gastrointestinal problems in humans. This is consistent with the results of studies of the physiological and morphological effects of olestra in animals and in humans. It is anticipated that olestra will be available in Canada in the near future. Patients will soon be asking their physicians about its use. This article provides an overview of olestra.

Coverage of cancer patients by hospice services, South Australia, 1990 to 1993

A population-based observational study of South Australian cancer patients was used to identify: the level of coverage of cancer patients by hospice services; the types of patients who miss out on hospice care; and the place of death of hospice and other cancer patients. We reviewed patients who died in 1990 and 1993 using the Central Cancer Registry database together with an identifier of hospice involvement. In 1990, 56 per cent of cancer patients who died had care from a hospice service, and this proportion increased to 63 per cent in 1993. Elderly patients, rural residents and those with a haematological malignancy were less likely than other patients to receive care from a hospice service, while patients aged between 40 and 60 years, longer survivors and those born in the United Kingdom and Europe were more likely to receive hospice care. Hospice involvement increased significantly between 1990 and 1993 for patients who died at home (59 to 73 per cent), in nursing homes (20 to 45 per cent), private hospitals (33 to 52 per cent) and public hospitals (48 to 55 per cent), but the proportion of patients with hospice involvement who died in country hospitals remained at 45 per cent. The increase in hospice coverage of terminal cancer patients reflects the continued integration of hospice care into the mainstream of health care delivery. The types of patients who miss out on hospice services should be given special consideration in the future planning of terminal care services.

Canadian Helicobacter pylori consensus conference. Canadian Association of Gastroenterology

These guidelines were created to dispel confusion and provide guidance about how the isolation of Helicobacter pylori infection has led to new opportunities and initiatives to improve patient care. The guidelines are designed for practical application in management decisions, but must remain flexible and amenable to change with new information. Updated versions of the recommendations are anticipated. Although it is now clear that H pylori is a major gastrointestinal pathogen, the extent of the clinical consequences posed by this microorganism has yet to be fully defined.

Increased immunolocalization of paraoxonase, clusterin, and apolipoprotein A-I in the human artery wall with the progression of atherosclerosis

Using immunolocalization techniques, we have shown that paraoxonase (Pon), clusterin, and apolipoprotein (apo) A-I accumulate in the artery wall during the development of atherosclerosis. In normal aortas (n = 6) there were low levels of extracellular Pon, clusterin, and apoA-I, immunoreactivity. The cytoplasm of smooth muscle cells in the media showed granular positivity for both Pon and apoA-I, indicating that these proteins were undergoing lysosomal degradation. This activity was also indicated by the presence of both intact and degradation products of Pon in smooth muscle cells as shown by Western blotting. With the progression of disease from fatty streaks (n = 3) to advanced atherosclerosis (n = 8) there was an increase in Pon, apoA-I, and clusterin immunoreactivity, indicating the increasing presence of these proteins with disease progression. These proteins are the components of a specific HDL subspecies that has been implicated in the prevention of peroxidative damage to phospholipids in LDL and membranes. The increase in Pon, clusterin, and apoA-I during the development of atherosclerosis may therefore represent a protective response to the oxidative stress associated with the development of atherosclerosis.

Evaluation of salivary antibodies to detect infection with Helicobacter pylori

Helicobacter pylori infection is an important cause of peptic ulcer disease and chronic gastritis. Infection with this bacterium stimulates the production of immunoglobulin (Ig) G antibody. Salivary IgG antibody tests to detect H pylori infection offer a convenient and noninvasive method of diagnosis. To evaluate an IgG salivary antibody kit, saliva was collected from 157 out-patients with dyspepsia referred for endoscopy to a tertiary centre. A salivary IgG ELISA antibody assay was performed using the Helisal Helicobacter pylori (IgG) assay kit, and at least four gastric biopsies were obtained. H pylori infection was confirmed by demonstration of the organism on Warthin-Starry silver stain (sensitivity 85%, specificity 55%). The prevalence of infection with H pylori was 30%. When the analysis was redone, excluding those treated with eradication therapy, the results were similar (sensitivity 86%, specificity 58%). The positive predictive value of the assay was 45% and the negative predictive value was 90%. Despite the ease of sampling, the assay used has limited diagnostic utility, lacking the predictive value to indicate which patients referred with dyspeptic symptoms to a tertiary care setting are infected with H pylori.

Cost effectiveness of alternative Helicobacter pylori eradication strategies in the management of duodenal ulcer

Published data and techniques for decision analysis were used to construct a model to estimate the cost effectiveness of nine alternative strategies for the management of patients diagnosed with uncomplicated duodenal ulcer. Two strategies of intermittent therapy with either ranitidine or omeprazole, one strategy of continuous maintenance treatment with ranitidine, and six strategies for ulcer healing and eradication of Helicobacter pylori infection were considered. Healing time curves were estimated by using published data, allowing for estimation of expected time for acute healing episodes. The expected number of weeks to heal per patient, in a one-year period, was estimated by combining healing time data with probability of ulcer recurrence. It was found that patients that underwent any of the six H pylori eradication regimens had fewer days with ulcer per year than those who underwent maintenance or intermittent ranitidine. Four eradication regimens had lower costs and better outcomes than ranitidine therapy. In comparing H pylori strategies, the two strategies of omeprazole plus one antibiotic (either amoxicillin or clarithromycin) are most costly than omeprazole plus two antibiotics (specifically amoxicillin and metronidazole or clarithromycin and metronidazole) and result in similar outcomes. Although omeprazole-based eradication regimens are more costly than ranitidine bismuth triple therapy, they are associated with fewer recurrences of ulcer and days of symptoms. A limitation of the analysis is that it did not incorporate issues of compliance and metronidazole resistance; however, the former concern may be less of an issue as H pylori regimens become simpler and shorter in duration.

Myocardial contrast echocardiography: reliable, safe, and efficacious myocardial perfusion assessment after intravenous injections of a new echocardiographic contrast agent

Reliable and reproducible myocardial opacification after intravenous administration of echocardiographic contrast agents has remained elusive. This study was performed to determine whether a new agent, FS069, a suspension of perfluoropropane-filled albumin microspheres (3.6 microns average microbubble size, concentration 8 x 8(8)/ml), could achieve safe and successful myocardial opacification in open-chest dogs. Seventeen dogs (group 1, n = 7, group 2, n = 10) underwent two-dimensional echocardiography before, during, and after the administration of intravenous FS069. Safety was evaluated by measuring arterial and pulmonary artery pressures, heart rate, blood gases, systolic function, myocardial blood flow, and postmortem analysis of myocardial viability by triphenyl-tetrazolium chloride staining. Efficacy to detect changes in regional myocardial perfusion was assessed by injecting FS069 at baseline, after sequential coronary occlusions and reperfusion, and during intravenous vasodilators with and without coronary occlusions. Results were compared with radiolabeled microspheres. FS069 was found to be safe and effective. In the absence of coronary occlusions, uniform myocardial opacification was observed in all dogs. A perfusion defect was observed in all dogs during coronary occlusions. Background-subtracted peak contrast intensity in the myocardium correctly identified regional myocardial blood flow changes and showed a significant correlation with radiolabeled microspheres (r = 0.65, p = 0.0001).

Outcome of patients discharged from a coronary care unit with a diagnosis of "chest pain not yet diagnosed"

OBJECTIVE

To determine the outcome and 3-year mortality rate among patients discharged from a coronary care unit (CCU) with a diagnosis of "chest pain not yet diagnosed."

DESIGN

Prospective observational cohort study.

SETTING

CCU in a university teaching hospital.

PATIENTS

All 158 eligible patients discharged from the CCU between August 1986 and December 1988. Of them, 27 refused to participate and 31 did not meet the inclusion criteria because of significant co-morbidity or transportation difficulties.

INTERVENTIONS

Evaluation with maximal and thallium exercise stress testing and four major gastrointestinal (GI) investigations: 24-hour intraesophageal pH monitoring, upper GI endoscopy with biopsy, esophageal motility studies and an upper GI barium series.

OUTCOME MEASURES

Results of investigations and incidence of recurrent chest pain, CCU readmission, coronary angiography, coronary artery bypass surgery, myocardial infarction and death at 6, 12, 24 and 36 months after the index visit.

RESULTS

Of the patients enrolled in the study 79% (79/100) had a normal exercise thallium stress test result, 74% (68/92) had an abnormal result from the 24-hour pH monitoring, 87% (82/94) had abnormal endoscopic results, 90% (84/93) had abnormal manometric results, and 89% (83/93) had signs of reflux with the barium series. At 3 years 50 patients had recurrent chest pain and 3 underwent coronary artery bypass surgery. Three patients died over the 3 years, all of noncardiac causes.

CONCLUSION

Many patients discharged from the CCU with a diagnosis of chest pain not yet diagnosed have a high incidence of esophageal disorders and a very low 3-year mortality rate. More research into the early and effective identification and management of patients with such a diagnosis is needed.

A population-based study of the coverage of cancer patients by hospice services

The aims were to determine the proportion of terminal cancer patients in South Australia who had involvement with a programme of hospice care, to identify the predictors of hospice involvement, and to consider the influence of hospice services, along with other variables, on the place of death. A file of patients of the State's hospice services who died in 1990 was compiled and linked to the population-based Central Cancer Register. We found that 1561 (56%) of the 2800 cancer patients who died in 1990 had care from a hospice service. Patients were less likely to be involved with a hospice service if they were 80 years or older, lived in a rural region, or had a haematological malignancy, and more likely to have hospice care if they had a survival time of more than six months, or were born in the UK or Europe. Patients of hospice services were more likely than other patients to die at home or in an inpatient hospice, and less likely to die in a nursing home or private hospital. A range of other factors were also found to be associated with place of death. We conclude that there has been a rapid acceptance of hospice care in South Australia, with a majority of the target population of cancer patients covered by services. Epidemiological research methods are useful for identifying gaps in the provision of care, and for determining the impact of various factors on where people die. This research is, therefore, important for the formulation and evaluation of policy for the delivery of terminal care.

Cost-effectiveness of Helicobacter pylori eradication for the long-term management of duodenal ulcer in Canada

BACKGROUND

A 1994 National Institutes of Health consensus panel recommended that eradication of Helicobacter pylori should be first-line therapy for persons with duodenal ulcer.

OBJECTIVE

To assess the cost-effectiveness of H pylori eradication relative to alternative pharmacologic strategies in the long-term management of persons with confirmed duodenal ulcer.

METHODS

Decision analysis model to estimate expected costs and symptomatic ulcer recurrences during a 12-month period for three general treatment strategies: (1) immediate H pylori eradication; (2) H pylori eradication at first ulcer recurrence; and (3) continuous maintenance therapy with a histamine2 receptor antagonist (ranitidine hydrochloride). Two H pylori eradication therapies were compared: classic triple therapy and omeprazole plus amoxicillin. Probabilities for ulcer recurrence are by meta-analysis of published randomized trials. Health care resources used in the management of duodenal ulcer recurrence were by expert physician panel. All costs are in 1993 Canadian dollars.

RESULTS

Duodenal ulcer recurrence at 6 months (symptomatic and asymptomatic) with placebo was 65.4% and 12.8% with maintenance ranitidine therapy. Where eradication of H pylori was successful (85% of patients), the ulcer recurrence rate to 12 months was 3.7%. Treatment with ranitidine and triple therapy to eradicate H pylori on first presentation has an expected 1-year cost of $253 with 15 symptomatic recurrences per 100 patients; H pylori eradication by omeprazole plus amoxicillin had similar expected costs ($272) and outcomes (15 recurrences per 100 patients). Both of these early H pylori eradication strategies were dominant (less costly with same or better outcomes) over intermittent or continuous maintenance ranitidine therapy or delayed (after first recurrence) H pylori eradication.

CONCLUSION

Our analysis provides economic evidence in support of the recent guidance that for persons with duodenal ulcer, early attempts to eradicate H pylori are recommended.

The effectiveness of esophageal stethoscopy in a simulated in-flight setting

PURPOSE

Previous research has confirmed the inability of flight nurses in an airborne BO-105 helicopter to hear breath sounds using normal or amplified transthoracic stethoscopy. The purpose of this study was to determine whether esophageal stethoscopy enabled effective auscultation of breath sounds in a simulated in-flight environment.

METHODS

The cabin-sound environment of an in-flight BO-105 was recorded and recreated in an audiology laboratory, where five flight nurses were evaluated listening to taped breath sounds via an esophageal stethoscope. This audiotape model, validated in a previously published study, used a tape consisting of 24 20-second segments. Each segment, the beginning of which was marked with a beep signal, consisted of 20 seconds of silence or breath sounds. The distal (esophageal) end of the esophageal stethoscope was attached to the tape recorder; the intensity level of breath sounds heard at the stethoscope earpiece was calibrated to equate the sound level of actual esophageal breath sounds recorded on a volunteer.

RESULTS

All nurses correctly identified the 24 taped segments as silent or including breath sounds 100% of the time.

CONCLUSION

In the simulated environment tested, esophageal stethoscopy enabled 100% accuracy in identification of breath sounds, as compared with previously reported 0% efficacy for standard transthoracic auscultation. Study in the actual patient-care environment is indicated to confirm the usefulness of esophageal stethoscopy in the in-flight setting.