Predicting outcomes in older patients undergoing vascular surgery using the Hospital Frailty Risk Score.

BACKGROUND: Frailty may explain why some older patients having vascular surgery are at high risk of adverse outcomes. The Hospital Frailty Risk Score (HFRS) has been designed specifically for use with administrative data and has three categories of frailty risk (low, intermediate and high). The aim of this study was to evaluate the HFRS in predicting mortality, and hospital use in older patients undergoing vascular surgery. METHODS: Routinely collected hospital data linked to death records were analysed for all patients aged 75 years or older who had undergone either endovascular or open vascular surgery between 2010 and 2012 in New South Wales, Australia. Multilevel logistic regression models were used to compare outcomes adjusted for patient and procedural factors, with and without frailty. RESULTS: Some 9752 patients were identified, of whom 1719 (17·6 per cent) had a high-risk HFRS. Patients in the high-risk frailty category had an adjusted odds ratio for death by 30 days after surgery of 4·15 (95 per cent c.i. 2·99 to 5·76) compared with those in the low-risk frailty category, and a similarly increased odds of death by 2 years (odds ratio 4·27, 3·69 to 4·95). Adding the HFRS to a model adjusted for age, sex, co-morbidity score, socioeconomic status, previous hospitalization and vascular procedure type improved the prediction of 2-year mortality and prolonged hospital stay, but there was minimal improvement for 30-day mortality and readmission. CONCLUSION: Adjusting for the HFRS in addition to other patient and procedural risk factors provided greater discrimination of outcomes in this cohort of older patients undergoing vascular surgery.

Exploring disparities in acute myocardial infarction events between Aboriginal and non-Aboriginal Australians: roles of age, gender, geography and area-level disadvantage.

We investigated disparities in rates of acute myocardial infarction (AMI) between Aboriginal and non-Aboriginal people in the 199 Statistical Local Areas (SLAs) in New South Wales, Australia. Using routinely collected and linked hospital and mortality data from 2002 to 2007, we developed multilevel Poisson regression models to estimate the relative rates of first AMI events in the study period accounting for area of residence. Rates of AMI in Aboriginal people were more than two times that in non-Aboriginal people, with the disparity greatest in more disadvantaged and remote areas. AMI rates in Aboriginal people varied significantly by SLA, as did the Aboriginal to non-Aboriginal rate ratio. We identified almost 30 priority areas for universal and targeted preventive interventions that had both high rates of AMI for Aboriginal people and large disparities in rates.

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.

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.

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.

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.