Randomized Controlled Trial of the Effect of an Exercise Rehabilitation Program on Symptom Burden in Maintenance Hemodialysis: A Clinical Research Protocol

Background

People receiving hemodialysis experience high symptom burden that contributes to low functional status and poor health-related quality of life. Management of symptoms is a priority for individuals receiving hemodialysis but limited effective treatments exist. There is emerging evidence that exercise programming can improve several common dialysis-related symptoms.

Objective

The primary aim of this study is to evaluate the effect of an exercise rehabilitation program on symptom burden in individuals receiving maintenance hemodialysis.

Design

Multicenter, randomized controlled, 1:1 parallel, open label, prospective blinded end point trial.

Setting

Three facility-based hemodialysis units in Winnipeg, Manitoba, Canada.

Participants

Adults aged 18 years or older with end-stage kidney disease receiving facility-based maintenance hemodialysis for more than 3 months, with at least 1 dialysis-related symptom as indicated by the Dialysis Symptom Index (DSI) severity score >0 (n = 150).

Intervention

Supervised 26-week exercise rehabilitation program and 60 minutes of cycling during hemodialysis thrice weekly. Exercise intensity and duration were supervised and individualized by the kinesiologist as per participant baseline physical function with gradual progression over the course of the intervention.

Control

Usual hemodialysis care (no exercise program).

Measurements

Our primary outcome is change in symptom burden at 12 weeks as measured by the DSI severity score. Secondary outcomes include change in modified DSI severity score (includes 10 symptoms most plausible to improve with exercise), change in DSI severity score at 26 and 52 weeks; time to recover post-hemodialysis; health-related quality of life measured using EuroQol (EQ)-5D-5L; physical activity behavior measured by self-report (Godin-Shepherd questionnaire) and triaxial accelerometry; exercise capacity (shuttle walk test); frailty (Fried); self-efficacy for exercise; and 1-year hospitalization and mortality.

Methods

Change in primary outcome will be compared between groups by independent 2-tailed t test or Mann-Whitney U test depending on data distribution and using generalized linear mixed models, with study time point as a random effect and adjusted for baseline DSI score. Similarly, change in secondary outcomes will be compared between groups over time using appropriate parametric and nonparametric statistical tests depending on data type and distribution.

Limitations

The COVID-19 pandemic restrictions on clinical research at our institution delayed completion of target recruitment and prevented collection of accelerometry and physical function outcome data for 15 months until restrictions were lifted.

Conclusions

The application of an exercise rehabilitation program to improve symptom burden in individuals on hemodialysis may ameliorate common symptoms observed in individuals on hemodialysis and result in improved quality of life and reduced disability and morbidity over the long term. Importantly, this pragmatic study, with a standardized exercise intervention that is adaptable to baseline physical function, addresses an important gap in both clinical care of hemodialysis patients and our current knowledge.

Acute successful management of a chainsaw injury to the roof of the left chest

This case report chronicles the experience of prompt resuscitation, beginning with the patient, and immediate surgery following the fatal malfunction of a chainsaw. The injuries were atypical for chainsaw injuries and involved total transection of the left subclavian artery and vein, total transection of the left brachial plexus and laceration to the apex of the left lung, among other injuries. A coordinated effort allowed for successful repair of the life- and limb-threatening injuries so that the patient could return to his young family in time for his 40th birthday.

Establishing minimally invasive cardiac surgery in a low-volume mitral surgery centre

INTRODUCTION

Despite early enthusiasm, minimally invasive cardiac surgery has had a low uptake compared with novel techniques in interventional cardiology. Steep learning curves from high-volume centres have deterred smaller units from engaging, even though low-volume centres undertake a large proportion of surgical interventions worldwide. We sought to identify the safety and experience of learning minimally invasive cardiac surgery after undertaking a structured fellowship at Blackpool Victoria Hospital, a low-volume centre.

MATERIALS AND METHODS

A retrospective analysis of outcomes for all consecutive minimally invasive cardiac surgery procedures performed via a right mini-thoracotomy at our institution between 2007 and 2017 was undertaken. Clinical outcomes included death, conversion to sternotomy, stroke, renal failure and other organ support. Cardiopulmonary bypass, aortic cross-clamp times and learning cumulative sum sequential probability method curves were also assessed to determine how safely the procedure was adopted.

RESULTS

A total of 316 patients were operated on for mitral, tricuspid, atrial fibrillation, septal defects or other conditions. The mean logistic European System for Cardiac Operative Risk Evaluation score was 7.0 (± 8.5). Conversion to sternotomy occurred in 12 patients (3.8%) and in-hospital mortality was 7 (2.2%). None of the converted patients died. The learning curves showed an accelerated process of adoption, similar to reference figures from a high-volume German centre.

DISCUSSION

It is possible for low-volume cardiac surgical centres to undertake minimally invasive surgical programmes with good outcomes and short learning curves. Despite technical complexities, with a team approach, the learning curve can be navigated safely.

A Higher Concentration of Dialysate Magnesium to Reduce the Frequency of Muscle Cramps: A Narrative Review

Purpose of review:

Strategies to mitigate muscle cramps are a top research priority for patients receiving hemodialysis. As hypomagnesemia is a possible risk factor for cramping, we reviewed the literature to better understand the physiology of cramping as well as the epidemiology of hypomagnesemia and muscle cramps. We also sought to review the evidence from interventional studies on the effect of oral and dialysate magnesium-based therapies on muscle cramps.

Sources of information:

Peer-reviewed articles.

Methods:

We searched for relevant articles in major bibliographic databases including MEDLINE and EMBASE. The methodological quality of interventional studies was assessed using a modified version of the Downs and Blacks criteria checklist.

Key findings:

The etiology of muscle cramps in patients receiving hemodialysis is poorly understood and there are no clear evidence-based prevention or treatment strategies. Several factors may play a role including a low concentration of serum magnesium. The prevalence of hypomagnesemia (concentration of <0.7 mmol/L) in patients receiving hemodialysis ranges from 10% to 20%. Causes of hypomagnesemia include a low dietary intake of magnesium, use of medications that inhibit magnesium absorption (eg, proton pump inhibitors), increased magnesium excretion (eg, high-dose loop diuretics), and a low concentration of dialysate magnesium. Dialysate magnesium concentrations of ≤0.5 mmol/L may be associated with a decrease in serum magnesium concentration over time. Preliminary evidence from observational and interventional studies suggests a higher dialysate magnesium concentration will raise serum magnesium concentrations and may reduce the frequency and severity of muscle cramps. However, the quality of evidence supporting this benefit is limited, and larger, multicenter clinical trials are needed to further determine if magnesium-based therapy can reduce muscle cramps in patients receiving hemodialysis. In studies conducted to date, increasing the concentration of dialysate magnesium appears to be well-tolerated and is associated with a low risk of symptomatic hypermagnesemia.

Limitations:

Few interventional studies have examined the effect of magnesium-based therapy on muscle cramps in patients receiving hemodialysis and most were nonrandomized, pre-post study designs.

Long-term survival after endoscopic vein harvest for coronary artery bypass grafting

INTRODUCTION

Endoscopic vein harvest is the technique of choice in North America, where it constitutes 80% of conduit harvest for coronary artery bypass grafting. The UK has much lower rates, despite demonstrable perioperative benefits. Concerns about patency and long-term survival are often cited as reasons for poor uptake and evidence in the literature thus far has only addressed mid-term outcomes. We sought to identify the long-term survival of patients undergoing endoscopic vein harvest compared with a contemporaneous cohort of open vein harvest.

MATERIALS AND METHODS

This was a retrospective cohort study of all consecutive patients undergoing isolated coronary artery bypass grafting at a single institution between 2007 and 2017. All-cause long-term mortality was compared using Kaplan-Meier curves and log-rank analysis.

RESULTS

A total of 7,527 patients undergoing coronary artery bypass grafting (1,029 receiving endoscopic vein harvest) were studied. The groups were well matched for preoperative characteristics, except that there were more patients with triple-vessel disease and good left-ventricular function in the endoscopic vein harvest group. There was no statistically significant difference in the long-term survival (p = 0.23). At five years (median follow-up), survival was 86.1% (95% confidence interval 85.3-87.0) in the open vein harvest group compared with 85.5% (95% confidence interval 82.8-88.2) in the endoscopic vein harvest group.

DISCUSSION AND CONCLUSION

Endoscopic vein harvest does not affect long-term survival in an unselected population. The contraindications for minimally invasive vein harvest in coronary artery bypass grafting are increasingly diminishing.

Is Assisted Peritoneal Dialysis a Solution for Northern Manitoba?

Background:

End-stage kidney disease (ESKD) continues to fundamentally impact the lives of First Nations (FN) patients. Home peritoneal dialysis (PD) offers patients more mobility and flexibility, but few Manitoba FNs have availed themselves of this option.

Objective:

This paper discusses Manitoba FNs' experience of PD, to highlight enablers and barriers to expanding the use of PD in rural and remote Manitoba communities.

Methods:

We analyzed interviews of individuals living with ESKD (N = 14), family caregivers (N = 14) and healthcare providers and administrators (N = 27).

Results:

Barriers to PD uptake include medical suitability, patients' distrust of home modalities and fear in their ability to manage. Other factors include limited family support and lack of appropriate housing.

Conclusions:

Assisted peritoneal dialysis (APD) is an emerging model where PD supplies are centrally located, and where a cohort of PD patients can provide mutual support with added assistance from an APD worker. This model could mitigate existing treatment barriers.

Assessing Symptoms, Concerns, and Quality of Life in Noncancer Patients at End of Life: How Concordant Are Patients and Family Proxy Members?

CONTEXT

It has become commonplace to use family caregivers as proxy responders where patients are unable to provide information about their symptoms and concerns to health care providers.

OBJECTIVES

The objective of this study was to determine the degree of concordance between patients' and family members' reports of patient symptoms and concerns at end of life.

METHODS

Sample dyads included a mix of patients residing at home, in a nursing home, in a long-term care facility, or in hospice. Diagnoses included patients with amyotrophic lateral sclerosis (n = 75), chronic obstructive pulmonary disease (n = 52), end-stage renal disease (n = 42), and institutionalized, cognitively intact frail elderly (n = 49). Dyads completed the Patient Dignity Inventory (PDI), the modified Structured Interview Assessment of Symptoms and Concerns in Palliative Care, and Graham and Longman's two-item Quality of Life Scale.

RESULTS

Concordance was less than 70% for seven of the 25 PDI items, with the lowest concordance (65.1%) for the item "not being able to continue with my usual routines." For all but one PDI item, discordance was in the direction of family members reporting that the patient was worse off than the patient had indicated. Where discordance was observed on the Structured Interview Assessment of Symptoms and Concerns in Palliative Care and Quality of Life Scales, the trend toward family members overreporting patient distress and poor quality of life continued.

CONCLUSION

Understanding discordance between patients and family member reports of symptoms and concerns is a valuable step toward minimizing patient and family burden at end of life.

Dignity and Distress towards the End of Life across Four Non-Cancer Populations

OBJECTIVE

The purpose of this study was to identify four non-cancer populations that might benefit from a palliative approach; and describe and compare the prevalence and patterns of dignity related distress across these diverse clinical populations.

DESIGN

A prospective, multi-site approach was used.

SETTING

Outpatient clinics, inpatient facilities or personal care homes, located in Winnipeg, Manitoba and Edmonton, Alberta, Canada.

PARTICIPANTS

Patients with advanced Amyotrophic Lateral Sclerosis (ALS), Chronic Obstructive Pulmonary Disease (COPD), End Stage Renal Disease (ESRD); and the institutionalized alert frail elderly.

MAIN OUTCOME MEASURE

In addition to standardized measures of physical, psychological and spiritual aspects of patient experience, the Patient Dignity Inventory (PDI).

RESULTS

Between February 2009 and December 2012, 404 participants were recruited (ALS, 101; COPD, 100; ESRD, 101; and frail elderly, 102). Depending on group designation, 35% to 58% died within one year of taking part in the study. While moderate to severe loss of sense of dignity did not differ significantly across the four study populations (4-11%), the number of PDI items reported as problematic was significantly different i.e. ALS 6.2 (5.2), COPD 5.6 (5.9), frail elderly 3.0 (4.4) and ESRD 2.3 (3.9) [p < .0001]. Each of the study populations also revealed unique and distinct patterns of physical, psychological and existential distress.

CONCLUSION

People with ALS, COPD, ESRD and the frail elderly face unique challenges as they move towards the end of life. Knowing the intricacies of distress and how they differ across these groups broadens our understanding of end-of-life experience within non-cancer populations and how best to meet their palliative care needs.

An Economic Assessment Model of Rural and Remote Satellite Hemodialysis Units

BACKGROUND

Kidney Failure is epidemic in many remote communities in Canada. In-centre hemodialysis is provided within these settings in satellite hemodialysis units. The key cost drivers of this program have not been fully described. Such information is important in informing the design of programs aimed at optimizing efficiency in providing dialysis and preventative chronic kidney disease care in remote communities.

DESIGN, SETTING, PARTICIPANTS, AND MEASUREMENTS

We constructed a cost model based on data derived from 16 of Manitoba, Canada's remote satellite units. We included all costs for operation of the unit, transportation, treatment, and capital costs. All costs were presented in 2013 Canadian dollars.

RESULTS

The annual per-patient cost of providing hemodialysis in the satellite units ranged from $80,372 to $215,918 per patient, per year. The median per patient, per year cost was $99,888 (IQR $89,057-$122,640). Primary cost drivers were capital costs related to construction, human resource expenses, and expenses for return to tertiary care centres for health care. Costs related to transport considerably increased estimates in units that required plane or helicopter transfers.

CONCLUSIONS

Satellite hemodialysis units in remote areas are more expensive on a per-patient basis than hospital hemodialysis and satellite hemodialysis available in urban areas. In some rural, remote locations, better value for money may reside in local surveillance and prevention programs in addition support for home dialysis therapies over construction of new satellite hemodialysis units.

Thoracotomy versus VATS: is there an optimal approach to treating pneumothorax?

Introduction

The 2010 British Thoracic Society guidelines recommend that a weighted decision be made by clinicians with regard to surgical intervention for pneumothorax as the video assisted thoracoscopic surgery (VATS) approach is better tolerated by patients but carries a higher rate of recurrence (5% vs 1%).

Methods

Overall, 163 patients underwent surgical intervention for pneumothorax at our institution and data were collected prospectively for almost 7 years. Of these, 86 patients underwent VATS under a single surgeon with extensive VATS experience to compensate for the associated learning curve while 79 patients underwent an open procedure.

Results

There was no statistically significant difference in the recurrence rate between the open and the VATS group (1% vs 3.5%, p=1.0). The VATS group was superior to the open group in terms of reduced postoperative bleeding (7.5% vs 0%, p=0.01), reduced number of intensive care unit admissions (16% vs 0%, p<0.01) and a reduced adjusted length of stay (3 vs 5.5 days, p<0.01).

Conclusions

A comparable recurrence rate is attainable with a VATS approach once the learning curve is surpassed and a reduction in morbidity is an additional merit.

Interdependence of Genotype and Growing Site on Seed Mineral Compositions in Common Bean

Essential minerals are considered as key determinants of optimum health and nutritive quality of common bean seed. This study aimed to identify genetically stable essential minerals in common bean. Eleven diverse common bean genotypes were grown in three distinct growing environments and 17 essential minerals were analyzed by Inductively Coupled Plasma-Optical Emission Spectroscopy. Genetic control of mineral composition in common bean seed was demonstrated by large (p<0.01) genotypic differences in Ca and Sr contents and moderate genotypic difference was observed in Fe content. Significant influence of genotype and environments (G×E) interaction was observed in the content of all minerals. The ratios between genetic and environmental variances and between genetic and G×E variances indicated the greater influence and stability of genetic factor on the concentration of Ca and Sr in common bean seed. Significant positive correlations among important minerals such as Zn with S, P, Fe and Na and Cu with K, Mg, Ni, P were identified. The stability of genetic effects on Ca and Sr concentration in common bean has been identified in this study. Calcium is one of the most important minerals which regulates many cellular processes and has important structural roles in living organisms. Further studies to characterize Ca physiology in common bean may identify genetic or biochemical markers to expedite breeding common bean with enhanced Ca concentration.

Effect of a preventive foot care program on lower extremity complications in diabetic patients with end-stage renal disease

BACKGROUND

Lower extremity complications are a major cause of morbidity and mortality in patients with end-stage renal disease (ESRD) and diabetes mellitus. Patient education programs may decrease the risk of diabetic foot complications.

METHODS

A preventive program was instituted, consisting of regular assessments by a foot care nurse with expertise in foot care and wound management and patient education about foot care practices and footwear selection. Medical records were reviewed and patients were examined. A comparison was made with data about patients from a previous study done from this institution prior to development of the foot care program.

RESULTS

Diabetic subjects more frequently had weakness of the left tibialis anterior, left tibialis posterior, and left peroneal muscles than non-diabetic subjects. A smaller percentage of diabetic subjects had sensory neuropathy compared with the previous study from 5years earlier, but a greater percentage of diabetic subjects had absent pedal pulses in the current study. The frequency of inadequate or poor quality footwear was less in the current study compared with the previous study.

CONCLUSIONS

The current data suggest that a foot care program consisting of nursing assessments and patient education may be associated with a decrease in frequency of neuropathy and improved footwear adequacy in diabetic patients with ESRD.

Home hemodialysis in the remote Canadian north: treatment in Manitoba fly-in communities

Manitoba has the highest prevalence of ESRD in Canada. Northern Manitoba is a very sparsely settled area with a high proportion of aboriginal ESRD patients. Relocating to urban areas for dialysis is psychosocially and culturally stressful to patients. Delivering dialysis care in a home setting has demonstrated advantages in both clinical, economic, and health related quality of life domains. Establishing home hemodialysis in very remote communities has significant challenges, including poor and inadequate housing, unreliable water supply, limited community medical backup, and poor road access to communities especially for delivery of supplies. These challenges necessitate the development of strong community partnerships, and well documented processes for contingencies. A dedicated interdisciplinary support and training team at the urban hub is essential.

Giant aneurysm of the ascending aorta

An ascending aortic aneurysm is a rare entity. The authors encountered an 85-year-old female patient with an uncomplicated ascending aortic aneurysm measuring 9 cm in diameter. She underwent an urgent operation involving replacement of the ascending aorta. Postoperatively, she developed mild renal failure and atrial flutter requiring direct current cardioversion. However, further recovery was good. The authors present this case including the operative management and a brief overview of this rare condition to reiterate that with an ageing population, this procedure can be done with an acceptable morbidity.

Model for equitable care and outcomes for remote full care hemodialysis units

BACKGROUND AND OBJECTIVES

Remotely located patients not living close to a nephrologist present major challenges for providing care. Various models of remotely delivered care have been developed, with a gap in knowledge regarding the outcomes of these heterogeneous models. This report describes a satellite care model for remote full-care hemodialysis units managed homogenously in the province of Manitoba, Canada, without onsite nephrologists. Survival in remotely located full-care units is compared with a large, urban full-care center with onsite nephrologists.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Data from a Canadian provincial dialysis registry were extracted on 2663 patients between 1990 and 2005. All-cause mortality after initiation of chronic hemodialysis was assessed with Cox proportional hazards regression. Both short-term (1 year) and long-term (2 to 5 years) survival were analyzed.

RESULTS

Survival for patients receiving remotely delivered care was shown to be better than for those receiving care in the urban care center with this particular Canadian model of care. Furthermore, there was no difference when assessing short- and long-term survival. This was independent of distance from the urban center.

CONCLUSIONS

Chronic hemodialysis patients receiving remotely delivered care in a specialized facility attain comparable, if not better survival outcomes than their urban counterparts with direct onsite nephrology care. This model can potentially be adapted to other underserviced areas, including increasingly larger urban centers.

Antigenic heterogeneity of IgA anti-GBM disease: new renal targets of IgA autoantibodies

Anti-glomerular basement membrane (anti-GBM) disease is an aggressive form of glomerulonephritis, usually mediated by immunoglobulin G (IgG) autoantibodies to the noncollagenous (NC1) domain of alpha 3(IV) collagen. Less is known about the target antigen(s) in patients with atypical anti-GBM disease involving IgA autoantibodies. We report a new case of IgA anti-GBM disease in a patient with a history of proliferative lupus nephritis who presented with increasing creatinine levels, proteinuria, and hematuria, but no clinical or serological evidence of lupus recurrence. Renal biopsy showed focal and segmental necrotizing glomerulonephritis with strong linear capillary loop IgA staining by means of immunofluorescence. Serological test results were negative for IgG or IgA autoantibodies against the alpha 3NC1 domain. By means of immunoblotting, IgA from patient serum bound to 38- to 48-kd antigens collagenase-solubilized from human GBM, but not to purified NC1 domains of GBM collagen IV. The target of patient's IgA autoantibodies thus was identified as a novel GBM antigen, distinct from the alpha 3NC1 domain or other known targets of anti-GBM IgA autoantibodies. Clinical resolution was attained by means of conventional treatment with steroids and cyclophosphamide. The diversity of antigens recognized by anti-GBM IgA autoantibodies highlights the importance of renal biopsy for the reliable diagnosis of this rare condition because conventional serological immunoassays likely would yield false-negative results.

Ten year experience of bioabsorbable mesh support in pectus excavatum repair

INTRODUCTION

We reviewed 10 years experience in the treatment of this deformity using a retro-sternal bioabsorbable mesh in place of a metallic device to lift and stabilise the sternum. Moreover, the mesh supports the thoracic and upper abdominal wall reconstruction.

MATERIALS AND METHODS

From January 1990 to December 2000, in our Thoracic Surgery Unit, 65 patients with PE were assessed for surgical repair, mean age 16+/- 3.5 years, fronto sagittal thoracic index (FSTI) 0.21, ranging from 0.15-0.33. Twenty-three of them underwent surgical correction after initial assessment, 22 were deferred and sent to physiotherapy. At a subsequent assessment, five of the patients sent to physiotherapy were deemed to require surgery.

RESULTS

Of the 28 patients who underwent surgery, 2 (10%) presented a mild recurrence of PE after 1 year (0.30<FSTI>0.34), meanwhile all other patients maintained a FSTI>0.34. For all patients the improvement in FSTI was statistically significant, p = 0.001. Patients satisfaction after 24 months was thus shared: excellent 18 patients (65%), good seven patients (25%), fair one patient (3.5%) and poor two patients (7%). No major complications were observed in preoperative period. Patients mobilisation was soon achieved thanks to the postoperative pain control and the absence of retro-sternal metallic support.

CONCLUSIONS

The introduction of bioabsorbable mesh in the Robicsek technique is a safe procedure related to a high percentage of success. The high tolerance of the material reduces the inflammatory reaction. Moreover, the procedure prevents patients from having complications caused by retro-sternal device dislodgment, avoiding a second intervention for device reposition and reducing the postoperative chest pain achieving an early patient mobilisation. In the end a complete reconstruction of the upper abdomen wall has been produced.

Leukocyte reduction of red blood cell transfusions does not decrease allosensitization rates in potential kidney transplant candidates

A significant proportion of potential kidney transplant candidates continue to periodically require blood transfusions that carry a risk of allosensitization. Leukocyte reduction (leukoreduction) of blood products has been proved to reduce transfusion-associated allosensitization in patients with hematologic malignancies; however, the effect in potential kidney transplant candidates is unknown. A total of 112 kidney transplant candidates who received red blood cell transfusions while on the transplant waiting list were identified retrospectively. Sixty received a transfusion before leukoreduction (non-LR), and 52 received a transfusion after the local implementation of universal leukoreduction of blood products (LR). There was no difference in transfusion-associated allosensitization rates in patients who received a transfusion during the two eras (non-LR 27% [16 of 60] versus LR 33% [17/52]; NS). Likewise, no difference was observed in subgroups identified as being at high risk of allosensitization (previous pregnancy, transplant, or five or more previous transfusions) or at low risk (no previous allogeneic exposures) (high risk: non-LR 52% versus LR 55%; low risk: non-LR 10% versus LR 8%). Multivariate analysis revealed previous pregnancy to be the only significant risk factor associated with transfusion-associated allosensitization (relative risk, 8.2; 95% confidence interval, 2.4 to 24.0; P = 0.0001). Leukoreduction, in particular, was not associated with any protective effect. In summary, leukoreduction of red blood cell transfusions does not confer any protection against transfusion-associated allosensitization for potential kidney transplant candidates. Physicians who care for patients with ESRD must continue to practice careful transfusion avoidance while alternative strategies to minimize transfusion associated allosensitization are sought.

Calciphylaxis is usually non-ulcerating: risk factors, outcome and therapy

BACKGROUND

Calciphylaxis, historically considered rare, seems to be increasing in frequency. In our single center, 36 new cases have accumulated in seven years. The majority of these cases were non-ulcerating, which we believe to be early disease, in contradistinction to the vast majority of published cases that presented with ulcers.

METHODS

Prospective data were collected on all patients with calciphylaxis. As well, a case control study, with two controls per patient, was performed on patients presenting with non-ulcerating plaques.

RESULTS

The incidence of calciphylaxis in dialysis patients increased with a rate of 4.5/100 patient-years in the past three years. Eighty percent of cases presented with non-ulcerating subcutaneous plaques in the calves, easily confused with cellulitis. In those patients presenting with plaques only, the mortality rate was 33% at six months. Once ulceration develops, the mortality rate increased to above 80%. Bone scan was positive in 97% of patients. Steroid therapy appeared to be beneficial in some patients. Peritoneal dialysis, female sex and diabetes were risk factors. In the case control study of patients presenting with plaques only, serum phosphate (OR 2.6; 95% CI 1.05 to 6.45, P = 0.038) and Ca x P product (OR 1.46; 95% CI 1.02 to 20, P = 0.038) predicted the disease, as did being on calcium salts + vitamin D (OR 4.05; 95% CI 1.14 to 14.5, P = 0.03).

CONCLUSIONS

Calciphylaxis is no longer rare. It is usually nonulcerating and can be diagnosed clinically in all patients. These patients have a high mortality, especially once ulceration occurs. Calcium salts plus vitamin D, as well as serum Ca x P product and high serum P increase the chance of the diseases. Therefore, the disease may be preventable. Steroids may be of benefit to some patients.

Effect of low molecular weight heparin (fragmin) on bleeding after cardiac surgery

BACKGROUND

Fragmin (Dalteparin, Pharmacia Ltd, Milton Keynes, UK), a low molecular weight heparin, is now recommended in the treatment of unstable angina. Due to the greater bioavailability and longer half-life of Fragmin compared with conventional heparin we postulated that this may influence postoperative bleeding after cardiac surgery for unstable angina.

METHODS

We investigated the influence of the agent on postoperative bleeding after cardiac surgery. Patients undergoing first-time coronary artery bypass grafting were prospectively studied in four groups: group A (n = 100) were elective patients; group B (n = 60) had unstable angina and received conventional heparin intravenously until operation; group C (n = 115) received Fragmin with the last dose administered more than 12 hours before surgery; and group D (n = 115) received Fragmin within 12 hours of operation.

RESULTS

Patients in group D had significantly greater blood loss (p < 0.001) and increased blood transfusion than groups A, B, and C (p = 0.047). Patients receiving Fragmin more than 12 hours before surgery (group C) had similar rates of blood loss and transfusion to group B (p > 0.05) but greater than in group A (p = 0.021). There were no differences in reopening rate.

CONCLUSIONS

The risks of bleeding and transfusion must be weighed against the risks of acute ischemic events if Fragmin is stopped more than 12 hours before operation.

Early postoperative capsular block syndrome related to saccadic-eye-movement-induced fluid flow into the capsular bag

PURPOSE

To determine the relationship between saccadic eye movements and the development of early postoperative capsular block syndrome.

SETTING

Fundacion Oftalmologica, Los Andes, Santiago, Chile.

METHODS

An artificial experimental setup was designed to reproduce the anatomical, hydrodynamic, and kinetic conditions of an early postoperative pseudophakic eye with a capsulorhexis and intracapsular intraocular lens (IOL) implantation. An electromechanical transducer driven by a digital-to-analog converter was used to mimic saccadic eye movements at physiological speeds and accelerations. Position information and differential pressure measurements between the intracapsular space and the extracapsular space were digitized. Various anterior capsule-IOL configurations were tested including partial adhesion of the anterior capsule to the lens.

RESULTS

Saccadic movements increased intracapsular pressure by displacing fluid into the capsular bag. This finding was inconstant and only observed when the capsular rim adhered to the IOL optic by more than 70%. Development of positive intracapsular pressure was noted above 4 mm Hg.

CONCLUSION

A valve-like mechanism formed by the capsulorhexis rim partially adhered to the IOL optic can occur postoperatively. Under these conditions, saccadic eye movements can increase intracapsular pressure by a unidirectional inertial displacement of fluid into the capsular bag.

Effect of pergolide on restless legs and leg movements in sleep in uremic patients

Restless legs syndrome (RLS) and periodic limb movements in sleep (PLMS) are disorders that are common and disturbing to uremic patients. The treatment of these is problematic. Eight patients on chronic hemodialysis and continuous peritoneal dialysis completed a double-blind placebo-controlled crossover study using incremental doses of pergolide up to 0.25 mg at bedtime for treatment of RLS and sleep disruption. Five patients (62.5%) noted subjective improvement in restless legs symptoms and sleep quality. Objective results were improved only slightly by treatment. The percentage of the first hour in bed during which leg movements occurred decreased from 20.5 +/- 6.0 to 11.5 +/- 3.3, p < 0.05. However, findings during sleep were less positive. The following measures were not significant between placebo and treatment: leg movements per hour of sleep [53.7 +/- 22.3 vs 35.8 +/- 11.8 (p = 0.2)]; and percentage of sleep time spent with leg movements [5.5% +/- 3.2 vs 4.4% +/- 1.4 (p = 0.37)]. Patients continued to have very disrupted sleep, and we could not document an objective improvement in sleep architecture. Thus, although pergolide at the dose of 0.25 mg at bedtime provided subjective improvement in symptoms of restless legs and quality of sleep, and objectively decreased leg movements during the first hour in bed, objectively sleep continued to be disrupted. In this small patient group, the response to pergolide was not uniform, and further investigation is required to test effectiveness at higher doses.

Results of preprocedure and postprocedure toe cultures in orthopaedic surgery

This study was to determine whether there is any benefit to wrapping the toes sterilely during orthopaedic procedures not involving the foot but performed on the lower extremity. The group studied consisted of 12 patients who had an orthopaedic procedure performed in which the foot and toes were included in the surgical prep, but not involved in the surgical procedure. Nine of the 12 patients (75%) had positive results from preprocedural aerobic cultures and two of the 12 (16.6%) had positive results from preprocedural fungal cultures. Recolonization of the bacteria between the toes was also demonstrated. Sterile draping of the toes would minimize the risk of infection and also protect against bacteria that recolonize during the procedure.

Acetabular fractures

Acetabular fractures are not uncommon injuries of the pelvis. They are most frequently associated with high energy trauma such as that seen in a motor vehicle accident. Management of patients with acetabular fractures includes careful attention to ATLS (advanced Trauma Life Support) protocols and delayed operative treatment of the acetabular fractures. Diagnostic evaluation with plain radiography and CT is used to plan the treatment approach. Treatment includes not only the recognition of the fracture but avoidance of early and late complications. Emergent treatment includes closed reduction of associated hip dislocations followed by skeletal traction. Delayed reconstruction at four days after the injury decreases intraoperative blood loss by allowing retroperitoneal hemorrhage to subside. Final outcome after acetabular trauma depends not only on the reconstruction of the fracture, but the avoidance of complications. Acetabular fractures are becoming an increasingly common orthopedic injury. Fractures of the acetabulum (or hip socket) are most commonly seen after motor vehicle accidents. Young patients (18 to 30 years old) are typically affected. A frequent mechanism of injury is a direct blow to the anterior aspect of the knee with the hip flexed such as a dashboard injury in an automobile accident. Other mechanisms of injury include direct blows to the lateral aspect of the hip as in a fall from a height or a side impact automobile collision.

Effects of cholinergic drugs and 4-aminopyridine on cat ciliary muscle contractility

The effects of some cholinergic agents and 4-aminopyridine (4-AP) on neurally mediated contractions of in vitro cat ciliary muscle preparations were studied. The contractile response to trains of stimuli was enhanced by eserine and completely blocked by tetrodotoxin or atropine. Low concentrations of carbachol did not modify muscle resting tension but clearly attenuated contractile response to electrical stimuli, while higher concentrations increased the resting tonus leading to contracture which did not respond to further stimulation. 4-AP is known to be a potassium-channel blocking drug that increases neurotransmitter release at nerve terminals during the action potential. This substance exhibited a dose-related potentiation of the evoked ciliary muscle contractions without changing resting tension. The eventual reducing effect of 4-AP on the accommodative convergence/accommodation ratio (AC/A) is discussed in relation to its potential clinical application in certain strabismus patients.

Electrophysiological effects of 4-aminoquinoline on frog atrial contractile fibres

The effects of 4-aminoquinoline (4-AQ), a drug structurally related to 4-aminopyridine, were studied on atrial contractile fibres from the amphibian Caudiverbera caudiverbera by means of intracellular electrodes. In concentrations that did not change resting potential, 4-AQ (0.25-1.5 mM) reduced upstroke velocity, action potential amplitude (APA) and overshoot in a dose-dependent manner. 4-AQ also prolonged action potential duration (APD) and the fibre effective refractory period (ERP), making the ratio ERP/APD greater than one. These effects were reversible by washing. The drug-induced reduction of upstroke velocity was frequency-dependent. This effect and increase of APD were more intense at higher values of resting potential. All effects produced by 4-AQ remained constant in either high or low external K+ concentrations. The depressant effects of this compound on upstroke velocity, overshoot, APA as well as increase of APD were antagonized by doubling the extracellular Na+ concentration. Data presented support the view that 4-AQ exerts its effects on the frog heart by blocking both sodium and potassium channels, thus causing quinidine-like actions.

A rational approach to drug use in pregnancy

Abnormalities occur in approximately three percent of all newborns. Of these, about five to 10 percent are caused by teratogens with an estimated one percent the result of drug use. The teratogenic effects of drugs are time related, species related, and dose related. Presented below is information about drugs known and suspected of producing teratogenic effects. Also, counseling of the gravida is discussed. Nurses need to communicate accurate information to the patient and then allow the patient to weigh the benefits of the drug against its potential risk.

Acceptance of amniocentesis by low-income patients in an urban hospital

A study was made of increased accessibility of genetic services to low-income obstetric patients in Atlanta, Georgia. The proportion of black patients averaged 83%. Of 522 patients counseled from August, 1976, through 1978, 157 were offered amniocentesis, and 95 (61%) elected the procedure. For most of the patients (120, or 76%) who were eligible for amniocentesis, age (greater than or equal to 35 years at delivery) was an indication; and of these, only six (5%) had any prior knowledge of genetic risk. During the same time interval, 188 patients over 35 years of age who initiated prenatal care too late for prenatal diagnosis were counseled in the hospital after delivery; 101 (54%) indicated that they would have accepted amniocentesis. The conclusion was that (1) genetic services are acceptable to this socioeconomic group, and (2) accessibility and publicity are needed to promote utilization in this population.