Accreditation: A Quality Improvement Strategy for the Community-Based Family Practice

Five Alberta family practices were the first of their kind to pursue Accreditation Canada's Primary Care Accreditation in 2013-2015. This study examines the impact of accreditation as a quality improvement (QI) strategy for community-based/fee-for-service family practices. Pre-/post-accreditation data received on clinic compliance with accreditation standards, provider-reported work-life and patients' self-rated health status/care show massive improvement in accreditation-rated compliance scores, which were disproportional to provider-/patient-rated changes. A Donabedian-inspired explanation states that accreditation measures predominantly structures, whereas survey-sought provider/patient perspectives focus on process and outcomes. Costs and human resources burdens aside, clinics saw benefits in accreditation-incented QI initiatives and formal recognition of clinic excellence, albeit antecedent.

Impact of a Primary Care After-Hours Clinic on Avoidable Emergency Department Visits and Costs

OBJECTIVES

After-hours clinics (AHCs) have been identified as a means to improve primary care access. The study objective was to evaluate the impact of AHC intervention on avoided emergency department (ED) visits and cost savings.

Achievement of Accreditation by Community-Based Family Practice - Workload and Cost Analysis

Five Alberta family practices achieved accreditation with Accreditation Canada in 2013-2015. This study conducted a workload and cost analysis of achieving accreditation. Human resources (HR) comprised 95% of the total cost. Document preparation constituted 76% of workload and 68% of total HR costs. Centralized content experts were tasked with document write-up. Clinics focused on survey preparation: 56% of staff participated, with the workload being the heaviest on managers. In CAD (2018 $ value), per capita cost was the highest for the 2-physician clinic ($65.78) and lower for the 11-physician ($19.44) clinic. Other cost determinants included culture, organizational structure, physician/staff engagement and pre-existing compliance to standards. A cost-benefit analysis shall provide insights into system-level benefits.

An interprofessional collaborative practice model: primary-care clinical associates at the family practice setting

A persistent physician shortage challenges the ability of our healthcare system to meet the growing health needs of our aging population. Health system redesign must maximize the efficient use of available human resources. The Alberta Westview Primary Care Network (WPCN) introduced the Primary Care Clinical Associate (CA) program in 2005. This interprofessional collaborative practice model recruits nonphysician health professionals from various disciplines as autonomous, independent practitioners. They are associates of the family physician and use their full scope of practice to jointly care for a panel of patients in family practice settings. Three years after its inception, the CA program has grown steadily from two initial participating family practices to its current implementation in six of seven WPCN clinics. The present direction of Canadian primary healthcare reform is towards team approaches. Accordingly, the CA program has wide applicability provincially across Canada. The objective of this article is to describe in detail the design of the WPCN CA program including its conceptual framework and operational strategies and to share program implementation learning. This knowledge transfer will enable replication of the WPCN CA model, where appropriate, in other jurisdictions.

Implementation and evaluation of a community-based medication reconciliation (CMR) system at the hospital-community interface of care

The WestView community-based medication reconciliation (CMR) aims to decrease medication error risk. A clinical pharmacist visits patients' homes within 72 hours of hospital discharge and compares medications in discharge orders, family physicians' charts, community pharmacy profiles and in the home. Discrepancies are discussed and reconciled with the dispenser, hospital prescriber and follow-up care provider. The CMR demonstrates successful integration that is patient-centred and standardized, bridging the hospital-community interface and improving information flow and communication channels across a family-physician-led multi-disciplinary team. A concurrent research study will evaluate the impact of CMR on health services utilization and to develop a risk prediction model.

Aliskiren, a novel renin inhibitor, is renoprotective in a model of advanced diabetic nephropathy in rats

AIMS/HYPOTHESIS

Blockade of the renin-angiotensin system (RAS) with either ACE inhibitors or angiotensin receptor blocker is a key therapeutic strategy in slowing progression of diabetic nephropathy. Interruption of the RAS may also be achieved by blocking the activity of renin, the rate-limiting step in angiotensin II biosynthesis. However, it is not known whether drugs in this class also reduce the structural and functional manifestations of diabetic nephropathy.

METHODS

Using diabetic transgenic (mRen-2)27 rats, a rodent model of advanced diabetic nephropathy, we compared the efficacy of the renin inhibitor, aliskiren (10 mg kg(-1) day(-1) by osmotic mini-pump), with the ACE inhibitor, perindopril (0.2 mg kg(-1) day(-1) in drinking water), over a 16 week period.

RESULTS

Both perindopril and aliskiren reduced blood pressure, albuminuria and structural injury in experimental diabetic nephropathy, although not to the same extent. Aliskiren, at the dose used, did not reduce systemic blood pressure as much as perindopril, but both compounds were equally effective in reducing albuminuria and glomerulosclerosis in diabetic animals. The magnitude of interstitial fibrosis was attenuated to a greater degree by aliskiren than by perindopril.

CONCLUSIONS/INTERPRETATION

These findings suggest that therapies aimed at different targets within the RAS may not have identical effects in attenuating structural injury in experimental diabetic nephropathy.

The WestView Primary Care Network in the first six months: defragmenting the system

The objective of this article is to describe the integration of local primary care services through the development of a primary care network in Alberta. WestView Primary Care Network (WPCN) has the vision of integrating primary care teams into the health system. As a result, WPCN has incorporated integrative primary care teams into its clinical programs. Through its strategy of "defragmentation," WPCN is accomplishing the beginnings of service integration in the local health care context.

Carvedilol in the treatment of chronic heart failure

Along with the angiotensin-converting enzyme inhibitors (ACEIs), the beta-adrenergic receptor blockers have gradually emerged to be standard in the therapy of heart failure. Individual beta-blockers that have been shown to reduce all-cause mortality in patients with heart failure include bisoprolol, metoprolol and carvedilol. Carvedilol distinguishes from the other beta-blockers as being a non-selective beta(1)- and beta(2)-receptor blocker with (1)-receptor blockade effect and anti-oxidant properties. The drug does not have sympathomimetic activity and has vasodilatory effects attributable to its (1)-receptor blockade property. Experimental and clinical studies have confirmed carvedilol's vasodilator, anti-oxidant and anti-apoptotic properties, which may contribute to its effect in reversing cardiac remodelling in animal models and patients with heart failure. These pharmacological properties render carvedilol a potentially useful agent in the treatment of patients with heart failure. Early studies of carvedilol in heart failure have reported beneficial haemodynamic effects but variable effects on exercise tolerance and clinical well being. The large-scale US Carvedilol Heart Failure Program and the Australian/New Zealand Heart Failure Collaborative Research Group reported beneficial effects of carvedilol on mortality, morbidity and clinical well being in patients with mild-to-moderate heart failure. The recently reported but yet unpublished preliminary results of the COPERNICUS study suggest that carvedilol improves mortality and morbidity in patients with advanced heart failure and severe symptoms. At this time, it is unclear whether the ancillary pharmacological properties of carvedilol can be translated to more superior clinical benefit compared to the other beta-blockers. Preliminary studies examining surrogate end points suggest that carvedilol may improve left ventricular ejection fraction (LVEF) more than metoprolol. More conclusive information regarding their relative effects of clinical outcomes will await the completion of the COMET study, which compares the effect of metoprolol and carvedilol on mortality and morbidity, expected at the end of the year 2002.

Organic leachables from polymer-based dental filling materials

Results are reported from a study on the in vitro separation and identification of leachables from three different polymer-based dental filling materials by using a combined method of gas chromatography and mass spectrometry. The median number of separable organic leachables in these materials was between 14 and 22. Of these organic leachables the following were identified and quantified: DL-camphorquinone, 4-dimethylaminobenzoic acid ethyl ester (DMABEE), drometrizole, 1,7,7-trimethylbicyclo[2,2,1]heptane, 2,2-dimethoxy[1,2] diphenyletanone (DMBZ), ethyleneglycol dimethacrylate (EGDMA), and triethyleneglycol dimethacrylate (TEGDMA). Three of the leachables have previously been shown to provoke allergy. The range of log P(ow) values (representing the lipophilicity of these compounds) varied between 1.09 and 4.20. By multivariate data analysis, selected leachables from the tested materials were shown to separate into characteristic patterns. The results contribute to a characterization of potential hazardous compounds in polymer-based dental filling materials.

In vitro lymphocyte reactivity to gold compounds in the diagnosis of contact hypersensitivity

The use of the lymphocyte transformation test (LTT) in the diagnosis of contact hypersensitivity to gold was studied in 8 patients who had positive patch tests to gold salts, and in 8 control subjects who were negative to such patch tests. Gold sodium thiosulfate and gold chloride were added to cultures of lymphocytes, which were labeled by 3H-thymidine after 96 h. The lymphocyte stimulation index was calculated as the beta-counts in stimulated cultures divided by those in control cultures. The index was statistically significantly higher for the patient group (p=0.005-0.04) than for the control group. Levels of interferon-gamma (IFN-gamma) were determined for the supernatants of the lymphocyte cultures. An index IFN-gamma, which is defined as the level of IFN-gamma in stimulated cultures divided by that in control cultures, was statistically significantly higher for the patient group (p=0.01-0.006). The LTT stimulation index showed specificity and sensitivity between 67 and 80%, the respective values for Index IFN-gamma being between 73 and 100% when the patch test was used as a reference method. Evaluation of lymphocyte reactivity might be of future interest in the diagnosis of allergic reactions to gold if the sensitivity and specificity can be improved.

Increased cardiac and pulmonary endothelin-1 mRNA expression in canine pacing-induced heart failure

The canine model of pacing-induced heart failure (HF) simulates human dilated cardiomyopathy and is characterized by severe hemodynamic perturbations. We have previously demonstrated increased plasma endothelin-1 (ET-1) and left ventricular (LV) tissue peptide levels in this model. However, the gene expression of ET-1 has not been studied. Accordingly, we compared preproET-1 mRNA in the lungs and LV in control normal dogs, dogs with severe HF after 3 weeks of rapid pacing (pHF), and pHF dogs chronically treated with an ETA antagonist, LU135252 (pHF-LU). PreproET-1 mRNA expression was determined by ribonuclease protection assay and quantified by densitometry. In paced dogs, mean pulmonary artery pressure (PA) and LV end-diastolic pressure (LVEDP) increased markedly from 16 +/- 4 and 8 +/- 3 mm Hg, respectively, at baseline to 40 +/- 11 and 34 +/- 7 mm Hg, respectively, at 3 weeks (both p < 0.001). Treatment with LU135252 attenuated the increase in PA and LVEDP by 30% and 19%, respectively (p < 0.05 for both). Compared to controls, preproET-1 mRNA expression in the LV and lungs was markedly increased in pHF. This was not changed in the LV but was reduced in the lungs by treatment with the ETA antagonist. Increased pulmonary and LV expression of preproET-1 suggests that ET-1 plays a role in mediating the pulmonary hypertension and LV dysfunction characteristic of this model.

Salivary nickel and chromium in subjects with different types of fixed orthodontic appliances

The aim was to investigate nickel and chromium concentrations in saliva of patients with different types of fixed appliances. Saliva samples were collected from 47 orthodontic patients, ages 8 to 30 years. Four samples from each subject were collected: (1) before insertion of the appliance, (2) 1 to 2 days after, (3) 1 week after, and (4) 1 month after insertion of the appliance. A considerable variation in the concentrations of both nickel and chromium was observed. No significant differences were found between the no-appliance samples and the samples obtained after insertion of the appliances. The results suggest that nickel and chromium concentrations of saliva are not significantly affected by fixed orthodontic appliances during the first month of treatment.

Biologic testing of leachable aromatic compounds from denture base materials

The aromatic compounds phenyl benzoate (PB), phenyl salicylate (PS), and biphenyl (BP), which have previously been found to leach from poly(methyl methacrylate) denture base materials, were tested for cytotoxicity and biologic effects by L929 cells in culture. The octanol-water partition coefficient (log P(ow), a descriptor for the lipophilicity, was determined for the compounds. Cytotoxicity was evaluated by total cell growth and the plating efficiency test, and biologic effects by the total fatty acid composition of L929 cells. The commonly used tests, total cell growth and plating efficiency, did not show any significant changes of the cells due to the compounds. On the other hand, BP and PS, in particular, induced changes in the total fatty acid composition of L929 cells. The problem of bioavailability of aromatic compounds in cell culture assays and the relation to lipophilicity was addressed.

Immunocompetent cells adjacent to stainless steel and titanium miniplates and screws

Subepithelial soft tissue and bone obtained from the implant bed in the vicinity of stainless steel and titanium miniplates and screws were evaluated with respect to the presence of immunocompetent cells. The study included tissue specimens from 19 patients, in whom the implants (14 stainless steel and 5 titanium) had been in situ for more than 6 months. The ABC (avidin-biotin-complex) immunoperoxidase staining technique using monoclonal antibodies defining T lymphocytes (CD3+), macrophages (CD11c+) and Class II MHC (HLA-DR) was performed on EDTA demineralized, frozen bone tissue, and on fresh frozen soft tissue specimens. The results showed scattered T lymphocyte clusters, small numbers of macrophages and abundant expression of HLA-DR in the soft tissue adjacent to both stainless steel and titanium implants. There was no substantial difference in tissue reactions between implants of the two materials. The demineralized bone sections disclosed presence of immunocompetent cells in the connective tissue lining the periphery of the screw holes. Metal particles were seen in both the soft tissue and the bone specimens. We conclude that a mild tissue reaction takes place in the vicinity of miniplates and screws of stainless steel and titanium, and that the intensity of the reaction indicates that the implants are well tolerated by the host tissue.

Intermittent intravenous amrinone infusion: a potentially cost effective mode of treatment of patients with refractory heart failure

OBJECTIVE

To describe the experience of 41 New York Heart Association (NYHA) class III and IV heart failure patients treated with intermittent intravenous amrinone infusions in addition to conventional therapy.

BACKGROUND

Congestive heart failure is a condition often requiring repeated admission to hospital. Accordingly, a treatment modality which can reduce the number of admissions is desirable and potentially cost-effective.

DESIGN

Retrospective analysis of data from hospital and office charts.

SETTING

Community hospital with 640 active beds.

INTERVENTION

The initial amrinone infusion was administered in the hospital under electrocardiographic monitoring; subsequent infusions were given in an out-patient unit. A bolus injection of 0.75 mg/kg followed by an infusion of 5 to 10 micrograms/kg/min for 8 to 12 h was administered every two to six weeks as clinically indicated.

RESULTS

Results are reported for the first 51 months. Sixty-six per cent of the patients improved their NYHA class, 34% remained unchanged or deteriorated. Survival paralleled that of other studies involving similar patients not receiving nonglycoside positive inotropes. The number of days spent in the hospital in the six months after starting on amrinone compared with the six months before treatment was reduced to 50% (P < 0.05), and the number of hospital admissions in the six months after starting amrinone compared with the six months before decreased to 56% (P < 0.05).

CONCLUSIONS

Intermittent intravenous amrinone infusions can be given in an out-patient setting in patients with NYHA class III to IV heart failure. This program is cost-effective, reducing hospital admissions and in-patient hospital days.

Enteral feeding and infection in the immunocompromised patient

Evidence is accumulating that immunocompromised individuals are at an increased risk of infection from foodborne pathogens including Campylobacter jejuni, Listeria monocytogenes, Salmonella spp. Normal bacterial flora and contaminants of foods and enteral feeds can also result in nosocomial infection in susceptible individuals. Safe food handling, low-microbial diets, and measures to reduce bacterial contamination of enteral foods can reduce exposure to potential pathogens in the food supply.

Prevalence of nutrition-related problems among long-term survivors of allogeneic marrow transplantation

The nutritional status and prevalence of nutrition-related problems in 192 adult and child allogeneic marrow transplant recipients were evaluated 1 year after transplant in a retrospective chart review. Among these patients, 63% exhibited evidence of chronic graft-versus-host disease (GVHD) at the time of nutrition evaluation, including 44% with extensive disease who were receiving immunosuppressive therapy. Oral sensitivity was observed in 23% of all patients reviewed, and frank stomatitis occurred in 8%. The frequency of xerostomia was 18%; anorexia, 8%; reflux symptoms, 7%; diarrhea, 7%; steatorrhea, 5%; dysgeusia, 3%; and limited exercise tolerance because of dyspnea or joint contractures, 4%. Weight loss 3 to 12 months after transplant was experienced by 28%. Nutrition-related problems, changes in anthropometric indexes indicative of suboptimal nutritional status, and inadequate energy intake were observed more frequently in patients with extensive chronic GVHD than in patients without GVHD or in those with limited GVHD. Our findings indicate a high prevalence of nutrition problems among recipients of allogeneic marrow transplantation 1 year after transplant and, further, suggest the need for ongoing, community-based nutrition monitoring after discharge from a transplant center.

TLP Production Risers for 1200-m Water Depth

Summary.

A number of technically feasible alternative riser systems exist for tension leg platform (TLP) production systems in deep water. These include conventional steel, steel with added buoyancy, titanium, and carbon-fiber composite. The last three of these options provide substantial reductions in required riser tension for a 1200-m [3,935-ft] depth. For a minimum-size TLP, these reduced tensions translate into substantial reductions in fabricated steel weight. Replacing conventional top tensioners with a hard-mount or gimbal arrangement requires a relatively small increase in top tension, which would be balanced out by weight savings on the tensioning equipment. Operational concerns related to pressure and temperature changes must be addressed to ensure feasibility of the hard-mount or gimbal approach.

Introduction

Cost-effective development of deepwater acreage presents a major challenge in today's offshore oil industry. To meet this challenge, it will be necessary to rely, as much as possible, on proven technology developed progressively as the industry has pushed back water depth frontiers. The TLP, which has now completed its fourth year in the Hutton field, is an example of just such an incorporation of known technology. The TLP provides a stable platform for oil operations. The vertically tensioned mooring system almost totally eliminates vertical motion, allowing the adaptation of conventional fixed-platform drilling and production techniques. At the same time, the buoyancy of the hull and lateral compliance of the mooring system drastically reduce water-depth cost sensitivity (in comparison to fixed structures). The TLP subsystems of most concern in the move to much greater depths are the moorings and risers, which connect the hull to the seafloor. This paper focuses on the extension of TLP production risers to water depths almost an order of magnitude greater than Hutton. A deepwater development scheme based on a minimum-size TLP is explained, and riser system options for TLP's in 1200-m [3,935-ft] depths are reviewed. Gulf of Mexico design criteria are used to develop and to compare several alternative riser concepts. The impact of these concepts on the design of the TLP hull is discussed. Special considerations for riser operations in very deep water are also addressed.

TLP Deepwater Development Concept

The fundamental mission of a production TLP is to support the Christmas trees for the necessary production and injection wells on a stable deck above the water surface. This allows conventional (fixed-platform) well maintenance and adjustment without subsea intervention or remote-control subsea trees. Fully integrated TLPs (like Hutton) incorporate a number of additional capabilities (e.g., drilling and MI processing), requiring additional deck load and a larger, more costly TLP. For some fields (particularly smaller fields in deeper water), it may be advantageous to reduce the TLP payload to the bare essentials. This would include the risers and trees, a smaller workover rig, only essential process equipment (e.g., manifold and first-stage separation), and a smaller crew quarters. In this type of scheme, most of the processing, together with the export function, would be located on a separate facility that is less weight-sensitive than the TLP. This could be a fixed platform, if shallow water is nearby, or a tanker, if pipeline export is not feasible. Fig. 1 depicts a minimum-size TLP based on the scenario described above. Such a platform would be about one-third the size of the Hutton TLP for a Gulf of Mexico application (about 20 000 vs. 60 000 Mg [20,000 vs. 60,000 tonnes]). The wells would be predrilled by a floater anchored over a template at the TLP location. Some subsea satellite wells could be included to reach the extremities of the reservoir. This minimum-size TLP development concept is intended to enhance the fundamental adaptability of the TLP to a wide range of water depths. If it is to become a workhorse for deepwater development in the Gulf of Mexico and elsewhere, this type of TLP must be extendable from 500 to more than 1000 m [1,640 to 3,280 ft] with relatively little modification. Thus, the riser system must be adapted as water depth increases, preserving the basic concept of surface trees while controlling TLP payload. To illustrate this conceptual design process, consider a minimum-size TLP based on the above scenario with 24 single completion wells. The basic production riser configuration is illustrated in Fig. 2. It is designed to survive a 100-year Gulf of Mexico hurricane in place. Starting at the seabed, a hydraulic connector makes the structural connection with the wellhead. Casing (typically 24.4 cm [9 5/8 in.]) is tied back inside the wellhead with a pressure-tight connection. Inside the casing, production tubing runs continuously from downhole up into the riser.A thick-walled taper joint controls moments at the seabed without a dogleg causing the tubing to kink. At the top end, a conventional tree is fitted to the tubing and casing tieback. The riser is supported by tension applied from the TLP deck. The amount of riser tension necessary and the type of tensioning system are very important parameters in the TLP design.

Riser-System Options

Within the configuration outlined above, several options exist for the riser system. The most important options center on the choice of material for the outer riser pipe (casing) and the top interface design. The bottom interface also includes design options. but because its effect on the TLP is less dramatic, it becomes more of a detailed design selection.

Material Selection.

Available material choices for riser pipe include the following: steel, for conventional casing and the baseline system; steel with buoyancy: syntactic foam is placed around the lower riser to distribute and reduce top tension better; titanium, to save weight and top tension, to improve flexibility, and to prevent corrosion; and composite: carbon fiber and fiberglass/epoxy further reduce weight and top tension, while improving flexibility and corrosion resistance. Steel inserts are incorporated into the composite pipe to provide threaded connections between joints. Hybrid designs may also be developed (e.g., composite with conventional steel at the surface to improve fire resistance and conventional steel with titanium taper joints). These would tend to result, however, from detailed rather than conceptual design tradeoffs.

SPEPE

P. 558^

Effect of intervals between doses on the development of tolerance to isosorbide dinitrate

We studied the development of tolerance to isosorbide dinitrate in 12 patients with chronic stable angina pectoris. The effect of 30 mg of isosorbide dinitrate on treadmill exercise performance was assessed before and at one, three, and five hours after a single dose. As compared with placebo, the drug increased treadmill walking time until the onset of angina and until the development of moderate angina over the five-hour observation period (P less than 0.05). The patients then received 30 mg of isosorbide dinitrate twice, three times, and four times daily for a period of one week, and exercise performance was assessed before and at one, three, and five hours after the final morning dose. During sustained treatment two and three times daily, treadmill walking time was longer throughout the five-hour testing period than during the placebo phase (P less than 0.05). In contrast, during treatment four times daily, treadmill walking time was prolonged at one hour (P less than 0.05) but not at three and five hours after the last dose. We conclude that tolerance to the clinical effects of isosorbide dinitrate develops with a sustained dosage of 30 mg four times daily, but not when the drug is given two or three times daily.

Influence of skin site on bioavailability of nitroglycerin ointment in congestive heart failure

Nitroglycerin ointment (12.5 to 50 mg) was administered in randomized fashion to three skin sites, arm, chest, or thigh, to compare the hemodynamic effects and bioavailability in nine patients with severe congestive heart failure. Hemodynamic parameters and arterial nitroglycerin concentrations were measured frequently for 12 hours after each application and for 90 minutes after removal of the ointment. During the study, left ventricular filling pressures decreased from control values of 25.0 +/- 8.6 mm Hg (arm), 25.7 +/- 10.9 mm Hg (chest), and 23.7 +/- 8.4 mm Hg (thigh) to 20.4 +/- 8.6 mm Hg, 20.4 +/- 8.5 mm Hg, and 20.0 +/- 7.5 mm Hg; p less than 0.05, less than 0.01, and difference not significant respectively. Peak nitroglycerin concentrations were 5.1 +/- 4.3 ng/ml (arm), 6.2 +/- 6.0 ng/ml (chest), and 4.1 +/- 6.3 ng/ml (thigh). No significant difference was observed in mean arterial pressure, left ventricular filling pressure, right atrial pressure, or nitroglycerin concentration among the sites. These data show that nitroglycerin ointment has similar bioavailability on the arm, chest, or thigh and therefore can be used interchangeably on these skin sites.

In vitro release of nickel and chromium from different types of simulated orthodontic appliances

Five identical samples, each consisting of a fixed appliance, a headgear and a quad-helix for one-half of a dental arch, were immersed in 0.9% sodium chloride for 2 hours, 24 hours and 7 days. A control appliance was subjected to dynamic test conditions in a specially built "oral simulator" under similar test conditions. A significant release of nickel was detected from the quad-helix during the first two hours in static conditions, whereas during the following two periods significantly less nickel was released from the quad-helix than from the other appliances. The fixed appliance with simulated function showed a significantly higher cumulative release of nickel than the similar appliance in static conditions, 44.2 micrograms (SD 22.8) and 17.1 micrograms (SD 3.4). The total amounts of chromium released from the fixed appliance were significantly lower than those of nickel. No difference in the release of chromium was seen between the static and dynamic conditions. The results indicate certain differences in the amount and pattern of nickel release from different stainless steel orthodontic appliances in vitro. The release rate of nickel from dynamically loaded fixed appliances was found to be accelerated compared with that released under static conditions. Caution should be exercised when applying the results to the in vivo situation.