Mortality after admission for acute myocardial infarction in Aboriginal and non-Aboriginal people in New South Wales, Australia: a multilevel data linkage study

Background

Heart disease is a leading cause of the gap in burden of disease between Aboriginal and non-Aboriginal Australians. Our study investigated short- and long-term mortality after admission for Aboriginal and non-Aboriginal people admitted with acute myocardial infarction (AMI) to public hospitals in New South Wales, Australia, and examined the impact of the hospital of admission on outcomes.

Methods

Admission records were linked to mortality records for 60047 patients aged 25–84 years admitted with a diagnosis of AMI between July 2001 and December 2008. Multilevel logistic regression was used to estimate adjusted odds ratios (AOR) for 30- and 365-day all-cause mortality.

Results

Aboriginal patients admitted with an AMI were younger than non-Aboriginal patients, and more likely to be admitted to lower volume, remote hospitals without on-site angiography. Adjusting for age, sex, year and hospital, Aboriginal patients had a similar 30-day mortality risk to non-Aboriginal patients (AOR: 1.07; 95% CI 0.83-1.37) but a higher risk of dying within 365 days (AOR: 1.34; 95% CI 1.10-1.63). The latter difference did not persist after adjustment for comorbid conditions (AOR: 1.12; 95% CI 0.91-1.38). Patients admitted to more remote hospitals, those with lower patient volume and those without on-site angiography had increased risk of short and long-term mortality regardless of Aboriginal status.

Conclusions

Improving access to larger hospitals and those with specialist cardiac facilities could improve outcomes following AMI for all patients. However, major efforts to boost primary and secondary prevention of AMI are required to reduce the mortality gap between Aboriginal and non-Aboriginal people.

The importance of blood-borne viruses in elevated cancer risk among opioid-dependent people: a population-based cohort study

OBJECTIVE

To quantify cancer risk in opioid dependence and the association with infection by the oncogenic blood-borne viruses (BBVs) hepatitis C (HCV), hepatitis B (HBV) and HIV.

DESIGN

Cohort study.

SETTING

New South Wales, Australia.

PARTICIPANTS

All 45 412 adults aged 16 years or over registered for opioid substitution therapy (OST) between 1985 and 2007. Notifications of cancer, death and infection with HCV, HBV and HIV were ascertained by record linkage with registries.

MAIN OUTCOME MEASURES

The ratios of observed to expected number of cancers, standardised incidence ratios (SIRs), and the average annual per cent change (AAPC) in overall age and sex-standardised cancer incidence.

RESULTS

Overall cancer risk was modestly increased compared to the general population (SIR 1.15, 95% CI 1.07 to 1.23). Excess risk was observed for 11 cancers, particularly lung (4.02, 95% CI 3.32 to 4.82), non-Hodgkin's lymphoma (1.51, 95% CI 1.20 to 1.88) and liver (8.04, 95% CI 6.18 to 10.3). Reduced risk was observed for six cancers, including prostate (0.16, 95% CI 0.06 to 0.32) and breast (0.48, 95% CI 0.35 to 0.62). Individuals notified with HCV or HBV had a markedly increased risk of liver cancer; lung cancer risk was also increased in those with HCV. HIV was associated with an elevated risk of liver, anus and kidney cancer, non-Hodgkin lymphoma and Kaposi sarcoma. Cancer risk was not increased in individuals without a BBV notification, apart from pancreatic cancer (3.92, 95% CI 1.07 to 10.0). Cancer incidence increased significantly over time (AAPC 9.4%, 4.2% to 15%, p=0.001).

CONCLUSIONS

BBVs play a major role in the cancer risk profile of opioid-dependent individuals registered for OST. To address the dramatic increasing trend in cancer incidence, the OST setting could be utilised for cancer prevention strategies.

Major histocompatibility complex diversity in the endangered Ethiopian wolf (Canis simensis)

The major histocompatibility complex (MHC) influences immune response to infection and vaccination. In most species, MHC genes are highly polymorphic, but few wild canid populations have been investigated. In Ethiopian wolves, we identified four DLA (dog leucocyte antigen)-DRB1, two DLA-DQA1 and five DQB1 alleles. Ethiopian wolves, the world's rarest canids with fewer than 500 animals worldwide, are further endangered and threatened by rabies. Major rabies outbreaks in the Bale Mountains of southern Ethiopia (where over half of the Ethiopian wolf population is located) have killed over 75% of wolves in the affected sub-populations. In 2004, following a rabies outbreak, 77 wolves were vaccinated, and 19 were subsequently recaptured to monitor the effectiveness of the intervention. Pre- and post-vaccination rabies antibody titres were available for 18 animals, and all of the animals sero-converted after vaccination. We compared the haplotype frequencies of this group of 18 with the post-vaccination antibody titre, and showed that one haplotype was associated with a lower response (uncorrected P < 0.03). In general, Ethiopian wolves probably have an adequate amount of MHC variation to ensure the survival of the species. However, we sampled only the largest Ethiopian wolf population in Bale, and did not take the smaller populations further north into consideration.

Interpretation of cloud-climate feedback as produced by 14 atmospheric general circulation models

Understanding the cause of differences among general circulation model projections of carbon dioxide-induced climatic change is a necessary step toward improving the models. An intercomparison of 14 atmospheric general circulation models, for which sea surface temperature perturbations were used as a surrogate climate change, showed that there was a roughly threefold variation in global climate sensitivity. Most of this variation is attributable to differences in the models' depictions of cloud-climate feedback, a result that emphasizes the need for improvements in the treatment of clouds in these models if they are ultimately to be used as climatic predictors.

Low-coverage vaccination strategies for the conservation of endangered species

The conventional objective of vaccination programmes is to eliminate infection by reducing the reproduction number of an infectious agent to less than one, which generally requires vaccination of the majority of individuals. In populations of endangered wildlife, the intervention required to deliver such coverage can be undesirable and impractical; however, endangered populations are increasingly threatened by outbreaks of infectious disease for which effective vaccines exist. As an alternative, wildlife epidemiologists could adopt a vaccination strategy that protects a population from the consequences of only the largest outbreaks of disease. Here we provide a successful example of this strategy in the Ethiopian wolf, the world's rarest canid, which persists in small subpopulations threatened by repeated outbreaks of rabies introduced by domestic dogs. On the basis of data from past outbreaks, we propose an approach that controls the spread of disease through habitat corridors between subpopulations and that requires only low vaccination coverage. This approach reduces the extent of rabies outbreaks and should significantly enhance the long-term persistence of the population. Our study shows that vaccination used to enhance metapopulation persistence through elimination of the largest outbreaks of disease requires lower coverage than the conventional objective of reducing the reproduction number of an infectious agent to less than one.

Rabies in endangered Ethiopian wolves

With rabies emerging as a particular threat to wild canids, we report on a rabies outbreak in a subpopulation of endangered Ethiopian wolves in the Bale Mountains, Ethiopia, in 2003 and 2004. Parenteral vaccination of wolves was used to manage the outbreak.

Tonsillectomy in diagnosis of the unknown primary tumor of the head and neck

OBJECTIVES

The purpose of this study was to discuss the experience of one tumor registry with performing tonsillectomy in the diagnostic approach to unknown head and neck primary tumors. It also describes the importance of including tonsillectomy in this evaluation algorithm.

STUDY DESIGN

A retrospective chart review was done of 68 patients with either tonsillar or unknown primary squamous cell carcinoma culled from 829 patients seen from 1956 to 1996 at the head and neck tumor registry at the Naval Medical Center San Diego.

METHODS

Records from the head and neck tumor registry, radiation oncology service, and pathology department were reviewed with attention to presenting symptom, initial examination, diagnostic studies performed, and type and result of biopsies performed.

RESULTS

Thirty-four patients sought treatment for a neck lymph node metastasis of squamous cell carcinoma without an identifiable primary tumor site. Six of these (18%) had the primary site diagnosed by performing tonsillectomy ipsilateral to the presenting neck mass. Six of 14 T1 tonsillar carcinomas in this series had the primary site identified by tonsillectomy.

CONCLUSIONS

Despite a diligent search, a primary tumor site may not be found in the head and neck cancer patient. The tonsil may harbor an occult squamous cell carcinoma. The patient benefits from identification of the initial tumor site because postoperative irradiation ports may be reduced and because surveillance for recurrence may be improved. For these reasons, tonsillectomy should be performed ipsilateral to the presenting cervical metastasis if no other primary tumor site is identified.

Assessment of the respiratory actions of intramuscular morphine in conscious dogs

The actions on the respiratory system of 0.25, 0.5 and 1.0 mg kg(-1) morphine given intramuscularly were studied in conscious dogs. Dogs breathed oxygen with 0, 2 and 4 per cent CO(2), in that order, through a mask attached to a flow sensor and connected to a respiratory mechanics monitor. When a steady state period of respiration was reached breathing pure oxygen, respiratory rate, tidal volume, respiratory minute volume, peak expiratory flow rate and end tidal CO(2)(PetCO(2)) were measured. The respiratory minute volume and PetCO(2) were measured when the dogs breathed 2 and 4 per cent CO(2) in oxygen, the points plotted onto a graph and the gradient of the line, describing the PCO(2)/ventilation response, plus the intercept with the y-axis were determined. Measurements for each morphine dose were taken before injection and at 30 minutes, 1, 2, 3, 4, 6 and 8 hours post injection. The incidence of panting after morphine was dose related and it occurred in all dogs given the high dose. Morphine reduced the gradients of the PCO(2)/ventilation response lines and raised the intercept. Other changes were increased respiratory minute volume and peak expiratory flow and decreased PetCO(2) and tidal volume.

Complications of tonsillectomy and adenoidectomy

Adenotonsillectomy is generally safe surgery, but surgeons should be cognizant of potential complications and be prepared to manage them. Postoperative hemorrhage usually responds to local measures or cautery but can be life-threatening. Preoperative screening of coagulation profiles appears unnecessary. Anesthetic risks have declined with modern techniques, but airway risks, aspiration, and pulmonary edema are possible. Nasopharyngeal valving may be altered by velopharyngeal incompetence or nasopharyngeal stenosis. Sore throat, otalgia, fever, dehydration, and uvular edema are more common postoperative complaints. Less common complications include atlantoaxial subluxation, mandible condyle fracture, infection, eustachian tube injury, and psychological trauma. The prevalence, management, and strategies for avoidance of these are discussed.

Reliability of disposable intraoperative facial nerve stimulators

Facial nerve injury is one major morbidity of surgery performed along the course of this nerve. Surgeons frequently employ stimulators to identify and protect the nerve. Both disposable devices as well as larger, reusable stimulators are available. Despite their common use, relatively little documentation exists regarding the safety and reliability of these devices. We tested the electrical output of the four disposable, single-use motor nerve stimulators that are marketed in the United States. We found that each produced consistent stimulus output over time. One stimulator slightly exceeded the manufacturer's listed output while three devices produced significantly less voltage and current than specified by the manufacturer.

Modeling the Exchanges of Energy, Water, and Carbon Between Continents and the Atmosphere

Atmospheric general circulation models used for climate simulation and weather forecasting require the fluxes of radiation, heat, water vapor, and momentum across the land-atmosphere interface to be specified. These fluxes are calculated by submodels called land surface parameterizations. Over the last 20 years, these parameterizations have evolved from simple, unrealistic schemes into credible representations of the global soil-vegetation-atmosphere transfer system as advances in plant physiological and hydrological research, advances in satellite data interpretation, and the results of large-scale field experiments have been exploited. Some modern schemes incorporate biogeochemical and ecological knowledge and, when coupled with advanced climate and ocean models, will be capable of modeling the biological and physical responses of the Earth system to global change, for example, increasing atmospheric carbon dioxide.

Epidural administration of bupivacaine, morphine, or their combination for postoperative analgesia in dogs

OBJECTIVE

To compare the analgesic effects of epidural administration of morphine (MOR), bupivacaine hydrochloride (BUP), their combination (COM), and 0.9% sterile NaCl solution (SAL) in dogs undergoing hind limb orthopedic surgeries.

DESIGN

Blinded, randomized clinical trial.

ANIMALS

41 healthy dogs admitted for elective orthopedic surgeries involving the pelvis or hind limbs.

PROCEDURE

Analgesic and control agents were administered postoperatively prior to recovery from isoflurane anesthesia. Ten dogs received MOR, 0.1 mg/kg of body weight; 10 received BUP, 0.5%, 1 ml/10-cm distance from the occipital protuberance to the lumbosacral space; 11 received COM; and 10 received SAL epidurally. Dogs were monitored for 24 hours after epidural injection for pain score, heart and respiratory rates, blood pressure, time to required administration of supplemental analgesic agent, total number of supplemental doses of analgesic agent required, and plasma concentrations of cortisol, MOR, and BUP.

RESULTS

Pain scores were significantly lower in dogs in the COM and BUP groups than in dogs in the SAL group. Pain scores also were significantly lower in dogs in the COM group than in dogs in the MOR group. Time to required administration of supplemental analgesic agent was longer for dogs in the COM group than for dogs in the MOR and SAL groups. Total number of supplemental doses of analgesic agent required was lower for dogs in the BUP and COM groups than for dogs in the SAL group.

CLINICAL IMPLICATIONS

Postoperative epidural administration of COM or BUP alone provides longer-lasting analgesia, compared with MOR or SAL.

Epistaxis balloon catheter stabilization of zygomatic arch fractures

Isolated zygomatic arch fractures represent about 10% of facial fractures. Most are easily reduced, but about 7% require fixation. Stabilization with plates, transcutaneous wiring, and various packing materials may involve additional morbidity and other drawbacks. A double balloon epistaxis catheter may be inserted beneath the arch fracture site and inflated for 5 to 7 days as a relatively simple, reliable alternative that involves minimal morbidity.

Evaluation of pulmonary function and analgesia in dogs after intercostal thoracotomy and use of morphine administered intramuscularly or intrapleurally and bupivacaine administered intrapleurally

Eighteen dogs undergoing lateral thoracotomy at the left fifth intercostal space were randomly assigned to 1 of 3 postoperative analgesic treatment groups of 6 dogs each as follows: group A, morphine, 1.0 mg/kg of body weight, IM; group B, 0.5% bupivacaine, 1.5 mg/kg given interpleurally; and group C, morphine, 1.0 mg/kg given interpleurally. Heart rate, respiratory rate, arterial blood pressure, arterial blood gas tensions, alveolar-arterial oxygen differences, rectal temperature, pain score, and pulmonary mechanics were recorded hourly for the first 8 hours after surgery, and at postoperative hours 12, 24, and 48. These values were compared with preoperative (control) values for each dog. Serum morphine and cortisol concentrations were measured at 10, 20, and 30 minutes, hours 1 to 8, and 12 hours after treatment administration. All dogs had significant decreases in pHa, PaO2, and oxygen saturation of hemoglobin, and significant increases in PaCO2 and alveolar-arterial oxygen differences in the postoperative period, but these changes were less severe in group-B dogs. Decreases of 50% in lung compliance, and increases of 100 to 200% in work of breathing and of 185 to 383% in pulmonary resistance were observed in all dogs after surgery. Increases in work of breathing were lower, and returned to preoperative values earlier in group-B dogs. The inspiratory time-to-total respiratory time ratio was significantly higher in group-B dogs during postoperative hours 5 to 8, suggesting improved analgesia. Blood pressure was significantly lower in group-A dogs for the postoperative hour. Significant decreases in rectal temperature were observed in all dogs after surgery, and hypothermia was prolonged in dogs of groups A and C. Significant differences in pain score were not observed between treatment groups. Cortisol concentration was high in all dogs after anesthesia and surgery, and was significantly increased in group-B dogs at hours 4 and 8. Significant differences in serum morphine concentration between groups A and C were only observed 10 minutes after treatment administration. In general, significant differences in physiologic variables between groups A and C were not observed. Results of the study indicate that the anesthesia and thoracotomy are associated with significant alterations in pulmonary function and lung mechanics. Interpleurally administered bupivacaine appears to be associated with fewer blood gas alterations and earlier return to normal of certain pulmonary function values. Interpleural administration of morphine does not appear to provide any advantages, in terms of analgesia or pulmonary function, compared with its IM administration.

Uncertainties in Carbon Dioxide Radiative Forcing in Atmospheric General Circulation Models

Global warming caused by an increase in the concentrations of greenhouse gases, is the direct result of greenhouse gas-induced radiative forcing. When a doubling of atmospheric carbon dioxide is considered, this forcing differed substantially among 15 atmospheric general circulation models. Although there are several potential causes, the largest contributor was the carbon dioxide radiation parameterizations of the models.

The role of the Medicare fiscal intermediary and the regional home health intermediary, Part 2

The Medicare fiscal intermediaries (FIs) are private insurance companies that serve as the federal government's agents in the administration of the Medicare program, including the payment of claims. There are two primary functions of the FI--reimbursement review and medical coverage review. Hospital-based home health agencies relate to the hospital's FI for reimbursement purposes. All home health agencies are assigned to a special FI, the Regional Home Health Intermediary (RHHI), for medical review issues. This may be the same FI or a different one than that audits the hospital's cost report. Freestanding home health agencies deal with separate reimbursement and medical review divisions within a single RHHI's office. The author reviews the role of the Medicare FI and the RHHI and their relationship to home health agencies. Part 1 was featured in the June issue.

The role of the Medicare fiscal intermediary and the Regional Home Health Intermediary, Part 1

The Medicare fiscal intermediaries (FIs) are private insurance companies that serve as the federal government's agents in the administration of the Medicare program, including the payment of claims. There are two primary functions for the FI--reimbursement review and medical coverage review. Hospital-based home health agencies relate to the hospital's FI for reimbursement purposes. All home health agencies are assigned to a special FI, the Regional Home Health Intermediary (RHHI), for medical review issues. The same or a different FI may audit the hospital's cost report. Freestanding home health agencies deal with separate reimbursement and medical review divisions within a single RHHI's office. The author reviews the role of the Medicare FI and the RHHI and their relationship to home health agencies. Part 2 will appear in the July/August issue.

Management of recurrent otitis media

Recurrent otitis media is defined as three or more episodes of acute otitis media in six months or four or more episodes in one year, with the bouts of acute infection separated by intervals of full resolution. The disorder is common in children and is different from otitis media with effusion, the other frequently encountered chronic ear disease. Daily low-dose antibiotic therapy is recommended as initial prophylaxis against recurrent otitis media. Pressure-equalizing tubes may be used in patients who have more than one episode of breakthrough otitis media while receiving antibiotics. Adenoidectomy should be reserved for use when pressure-equalizing tubes fail or when insertion of a second set of tubes is required.

Indications for tonsillectomy and adenoidectomy

Tonsillectomy and adenoidectomy are separate procedures that should be performed for distinct reasons. Studies now indicate that severe, recurrent pharyngitis responds well to tonsillectomy. According to separate recommendations from the American Medical Association and the American Academy of Pediatrics, patients are candidates for tonsillectomy if they have four or more episodes of pharyngitis a year. Recurrent otitis media and chronic otitis media are improved by adenoidectomy, although placement of pressure-equalizing tubes remains the preferred initial treatment for these conditions. Adenotonsillectomy improves severe upper airway obstruction (cor pulmonale and obstructive sleep apnea), as well as milder forms of airway obstruction (loud snoring). The effectiveness of these procedures in proposed indications, such as sinusitis and adenoiditis, is less well substantiated.