Utility of repeat testing in the evaluation for von Willebrand disease in pediatric patients

BACKGROUND

Von Willebrand disease (VWD) is the most common inherited bleeding disorder and is caused by quantitative and qualitative defects in von Willebrand factor (VWF). The laboratory diagnosis of VWD in pediatric patients is complicated by VWF interassay and intra-assay variability, stress-induced elevations in VWF levels, and a lack of significant bleeding history with which to correlate test results.

OBJECTIVE

Guidelines recommend repeat testing in patients with a high suspicion of VWD and unclear laboratory assay results; however, no studies have evaluated the utility of repeat VWF testing in pediatric patients.

METHODS

This retrospective single-center cohort study aimed to determine clinical variables associated with requiring more than one test to diagnose VWD and to establish a cutoff VWF value above which further testing is not informative.

RESULTS

Of 811 patients evaluated for a suspected bleeding disorder, 22.2% were diagnosed with VWD, with ~70% diagnosed on the first test. Patients with VWD were younger (5.8 vs. 8.5 years, P = .002) and more likely to have a family history of VWD (38% vs. 22%, P < .001) than those without VWD. Univariate analysis failed to identify any clinical variables that correlated with needing multiple tests for a VWD diagnosis. A cutoff of 100 IU/dL for VWF antigen or activity on the first test yielded negative predictive values >95%.

CONCLUSIONS

We demonstrate that the majority of pediatric patients had diagnostic VWF values on the first set of testing. Pediatric patients without a family history of VWD and VWF levels >100 IU/dL may not need further testing to rule out the diagnosis of VWD.

National needs assessment of patients treated at the United States Federally-Funded Hemophilia Treatment Centers

AIM

The National Hemophilia Program Coordinating Center, with the U.S. Regional Hemophilia Network conducted a national needs assessment of U.S. Hemophilia Treatment Center (HTC) patients. The objectives were to determine: (i) To what extent do patients report that they receive needed services and education; (ii) How well do the services provided meet their needs; and (iii) What are the patients' perspectives about their care.

METHODS

A survey was mailed to active patients of 129 HTCs. Respondents completed the anonymous surveys on line or returned them by mail. Questions focused on management and information, access and barriers to care, coping, resources, and transition.

RESULTS

Of 24 308 questionnaires mailed, 4004 (16.5%) were returned. Most respondents reported very few gaps in needed services or information and reported that services and information met their needs. Over 90% agreed or strongly agreed that care was patient-centred and rated HTC care as important or very important. Identified gaps included dietary advice, genetic testing, information on ageing, sexual health and basic needs resources. Minority respondents reported more barriers.

CONCLUSION

This survey is the largest assessment of the HTC population. Respondents reported that the services and information provided by the HTCs met their needs. Quality improvement opportunities include transition and services related to ageing and sexual health. Further investigation of barriers to care for minorities is underway. Results will help develop national priorities to better serve all patients in the US. HTCs.

The clinical management of hemophilia and head trauma: a survey of current clinical practice among pediatric hematology/oncology physicians

BACKGROUND

Determining the appropriate evaluation for a pediatric patient with hemophilia and head trauma is a diagnostic challenge with no neuroimaging guidelines and limited clinical evidence to direct care.

PROCEDURE

A questionnaire, with two case scenarios, was emailed to members of the American Society of Pediatric Hematology/Oncology. The case scenarios involved asymptomatic toddlers with severe hemophilia who had either fallen from a height (case 1) or from standing (case 2). Respondents were asked to select from six management options. The case scenarios were then altered to include: a large palpable hematoma, prophylactic factor infusion 24 hr prior, the trauma occurred 48 hr prior, wearing a soft helmet, or emesis.

RESULTS

The completed response rate was 23% (252/1,077). Computed tomography (CT) was selected by 68.9% (#1) and 56.4% (#2) of respondents. In both case scenarios the presence of a palpable bruise resulted in a statistically significant increase in CT usage to 83.7% and 82.8% (P < 0.001). The use of prophylaxis did not result in a statistically significant decrease in CT usage. Duration of factor replacement was variable ranging from 1 to 4 days.

CONCLUSION

Physician self reported management of pediatric patients with hemophilia and head trauma is diverse. The use of CT imaging for mild head trauma in patients without signs or symptoms of intracranial hemorrhage was very common. The use of prophylaxis did not reduce the use of head CT imaging. This variation in clinical practice demonstrates the lack of evidence regarding the management of head trauma in patients with hemophilia.

Incidence of bleeding complications in pediatric patients with type 1 von Willebrand disease undergoing adenotonsillar procedures

OBJECTIVE

To review the incidence of postoperative bleeding in children with type 1 von Willebrand disease (VWD) who were treated with a single institution protocol.

STUDY DESIGN

We performed a retrospective study to determine the postoperative hemorrhage rate in pediatric patients with type 1 VWD who were treated via the Children's Hospital of Philadelphia institutional protocol. This protocol utilizes intravenous desmopressin (DDAVP), oral aminocaproic acid, and overnight observation.

RESULTS

Between the years of 2000 to 2006, 41 children with type 1 VWD underwent an adenotonsillar procedure and were treated with this protocol. Seven patients (17%) experienced delayed (>24 hours after surgery) postoperative hemorrhage requiring intervention. Five of the 7 patients required cautery to control the bleeding, and the remaining 2 patients responded to DDAVP and aminocaproic acid alone. Older age and lower VW antigen levels were associated with postoperative hemorrhage (P = .05).

CONCLUSIONS

Despite therapeutic intervention to decrease the risk of postoperative hemorrhage, the incidence of hemorrhage was higher in pretreated patients with type 1 VWD than in children without bleeding disorders. Further prospective studies are necessary to determine the optimal treatment to reduce bleeding complications in these patients.

Practice patterns in haemophilia A therapy - a survey of treatment centres in the United States

A survey was conducted to ascertain practice patterns for haemophilia A therapy in the United States. Questionnaire data were supplied by 52 haemophilia centres with a total of 4129 patients under treatment. Most participating centres were affiliated with academic/teaching hospitals or institutions. Patients below 5 years comprised 17% of the study population, 6-18 years 41% and >18 years 42%, and the apportionment across severity categories was 53% severe, 17% moderate and 30% mild. Among patients with severe haemophilia, 49% were receiving on-demand treatment, while 44% were receiving some form of prophylaxis (13% primary, 20% secondary and 11% tertiary). Primary prophylaxis was the most common type in children below 5 years of age, accounting for 25% of this age group. In children 6-18 years old, 58% were on some type of prophylactic regimen, while on-demand treatment was most frequent among adults. Difficulties of venous access were the most frequently cited barrier to instituting prophylaxis. Catheters were in use among 37% of the patients under primary prophylaxis and 14% of those on secondary prophylaxis. No major differences were observed in forms of therapy used between larger and smaller centres. These observations provide an extensive characterization of haemophilia A practice patterns in the United States.

Promoting safer sex among HIV-positive youth with haemophilia: theory, intervention, and outcome

The goal of the project was to develop and evaluate theory-based interventions designed to change sexual behaviour and promote safer sex practices of HIV seropositive young men and adolescents with haemophilia to prevent transmission to sexual partners and offspring. Safer sex was defined as abstinence, consistent condom use, or 'outercourse' (intimate, non-intercourse sexual behaviour). This project utilized the Transtheoretical Model developed by Prochaska and DiClemente, which describes behaviour change as an incremental, stage-based process. The 1-year intervention protocol consisted of two individual sessions and two peer-centred activities. One hundred and four adolescents, residing in 22 states, participated. Pre- and post-intervention evaluations were conducted to measure stage progression for participants. The number who were in the action or maintenance stage of change for safer sex was significantly greater at post-test than at pre-test (79 vs. 62%, P < 0.0001). Participants also reported an increased use of outercourse. In addition, significant increases in self-efficacy and knowledge regarding safer sex were demonstrated. Following these stage-based interventions, participants were significantly more likely to be engaging in safer sex behaviours than they were previously. These intervention activities can be adapted for use with other adolescent populations and for other behaviour change goals in adolescents with haemophilia.

Predictors of retention among HIV/hemophilia health care professionals

Health care professionals working with individuals with chronic medical illness, especially those infected with the Human Immunodeficiency Virus (HIV), may be at risk for burnout and departure due to various job stresses such as the death of patients and social stigma. Factors that prevent burnout and employee attrition are seldom studied. Two hundred thirteen staff (doctors, nurses and mental health workers) at a representative sample of Hemophilia Treatment Centers (HTC) completed instruments to measure Burnout (Maslach Burnout Inventory), and perceived job stresses and satisfaction (job tasks, interactions with colleagues and patient care). The staff were surveyed again after two years and their job status determined after 4 years. After 4 years, 35% of the staff had left the field of Hemophilia/HIV care. Univariate tests found that retention was significantly associated with initial job satisfaction, being married and low levels of stress with colleagues. Burnout, as measured by the Maslach Burnout Inventory, at baseline, was unrelated to job retention over 4 years. An adjusted multiple logistic regression of all significant variables found that colleague support was most related to retention (OR=2.8, CI=1.49,5.1). We conclude that attrition of highly trained staff is a significant issue for patients and HTCs. These data suggest the important role that a well-functioning team can have in buffering the inevitable stresses associated with HIV care. Mental Health professionals have considerable expertise in addressing these issues.

Complex regional pain syndrome in pediatric patients with severe factor VIII deficiency

Two boys with severe factor VIII deficiency that initially presented with acute onset of joint pain and swelling consistent with an uncomplicated hemarthrosis are reported. When appropriate management failed to provide resolution of symptoms, alternate diagnoses were considered. Both boys ultimately had complex regional pain syndrome (CRPS) diagnosed. The delay in diagnosis contributed to prolonged patient discomfort and lack of appropriate therapy. Complex regional pain syndrome encompasses a group of disorders that are characterized by pain severity or duration disproportionate to that expected. It is uncommon in the pediatric population. Because early diagnosis and appropriate treatment may improve outcome, it is important for practitioners to consider CRPS in the differential diagnosis of persistent pain in children with hemophilia.

Developing theory-based risk-reduction interventions for HIV-positive young people with haemophilia

Eleven haemophilia treatment centres in the United States collaborated in the Hemophilia Behavioural Intervention Evaluation Projects (HBIEP) to develop theory-based interventions to reduce the risk of HIV transmission from seropositive adolescents and young adults with haemophilia. While the Transtheoretical Model of Behaviour Change and the Theory of Reasoned Action provided the theoretical underpinnings, the exact form in which these theories would be applied depended on developmental research. This paper presents the various phases of the process to develop the theory based interventions: literature review, qualitative interviews, quantitative surveys, a provider survey, a materials review, and the actual planning. All or portions of this process could be applied to the development of interventions for many behaviour-change projects. A description of the HBIEP interventions is also provided.

Sexual behavior change among human immunodeficiency virus-infected adolescents with hemophilia. Adolescent Hemophilia Behavioral Intervention Evaluation Project Study Group

PURPOSE

To determine the factors associated with the adoption or maintenance of consistent safer sexual behaviors among human immunodeficiency virus-positive adolescents and young adults with hemophilia.

METHODS

One hundred eleven adolescents at 10 hemophilia care sites participated in an intervention program designed to increase safer sexual behaviors (abstinence, condom use, or nonpenetrative behavior). The theory-based intervention spanned 1 year. Adolescents attended individual sessions, small group activities, and an intensive group retreat.

RESULTS

Patients who maintained or improved safer sexual behaviors were compared with those who relapsed or did not improve. Logistic regression analyses found that improvement and maintenance of safer sexual behavior were significantly associated with perceived peer support for outercourse (odds ratio [OR]: 5.47; confidence interval [CI]: 1.4-20.8), perceived peer support for abstinence (OR: 5.08; CI: 1.2-20.1), and decreased general emotional distress (OR: 4.65; CI: 1.04-20.6). Perceived health status and previous sexual behavior were unrelated to change in safer sexual behavior.

CONCLUSIONS

These longitudinal data indicate that improvement and maintenance of safer sexual behavior among adolescents during an intervention is strongly associated with perceptions of peer support for safer sex and lesser degrees of emotional distress. Programs for human immunodeficiency virus-infected adolescents may require developmentally appropriate social and psychological approaches to impact peer norms and emotional well-being.

Superior in vivo response of recombinant factor VIII concentrate in children with hemophilia A

OBJECTIVE

Our previous experience with highly purified plasma-derived factor VIII (pdFVIII) concentrates showed that adult dosage recommendations were not applicable to children. In this study, we compared the in vivo response and recovery of recombinant factor VIII (rFVIII) with those of highly purified pdFVIII concentrate in children with hemophilia A.

STUDY DESIGN

Ten boys with severe factor VIII deficiency and no concurrent bleeding episodes participated in a masked, prospective, crossover study comparing factor VIII coagulant activity after infusion of 50 units of pdFVIII and rFVIII products per kilogram of body weight.

RESULTS

Mean peak factor VIII response with rFVIII was 1.91% +/- 0.14%, significantly better than the response observed with highly purified pdFVIII of 1.5% +/- 0.15% (p = 0.007). Mean peak factor VIII recovery was 100.5% with rFVIII versus 78.7% with pdFVIII (p = 0.007). Positive correlations between response to rFVIII and body surface area (r = 0.734, p = 0.015), body weight (r = 0.762, p = 0.01), and plasma volume (r = 0.659, p = 0.03) were observed.

CONCLUSIONS

Infusion of rFVIII produced a significantly better response and recovery in vivo than infusion of highly purified pdFVIII in children. The response in children after infusion of rFVIII was similar to the response previously observed in adults.

Loss of detectable antibody to hepatitis B surface antigen in immunized patients with hemophilia but without human immunodeficiency virus infection

We investigated the loss of detectable antibody directed against the hepatitis B surface antigen after immunization with hepatitis B vaccine in 55 patients who were seronegative for the human immunodeficiency virus and had hemophilia. Twenty percent of patients lost detectable antibody at a mean of 4.6 years after completion of immunization. Monitoring of hepatitis B serostatus or routine revaccination may be necessary.

Understanding the basics of beta thalassemia major

beta thalassemia major, a severe genetic disorder of the red blood cell, affects about 1,400 people in the United States, including children. Clinical management of this disorder has improved significantly in recent years, and ongoing research will lead to an even brighter outlook in the future.

Low recovery in vivo of highly purified factor VIII in patients with hemophilia

To assess whether the response and recovery of highly purified factor VIII products approach the levels predicted by use of manufacturers' suggestions, we studied response in vivo and percentage of recovery in boys and men with hemophilia after infusion of 50 IU of an immunoaffinity-purified factor VIII preparation (Hemofil M) per kilogram of body weight. We also studied dose response and percentage of recovery in the same boys after infusion of a factor VII concentrate prepared by solvent detergent treatment and gel filtration (Koate-HP). For boys the difference between mean peak factor VIII response with Hemofil M (1.02% +/- 0.07%) and the response with Koate-HP (1.21% +/- 0.10%) was not significant (p = 0.10), but the response of both products was considerably less than the predicted response of 2.0%. The response to Hemofil M in men (1.38% +/- 0.12%) was significantly better than the response in boys (p = 0.004) but, again, fell short of the anticipated response of 2.0%. In boys the percentage of recovery of Hemofil M was 38.4% +/- 2.1%, compared with Koate-HP recovery, which was 47.0% +/- 3.6% (p = 0.034). The percentage of recovery in men was 47.5% +/- 2.8%. The better response observed in men appears to be, in part, a function of larger body size. We conclude that peak factor VIII response and recovery in boys and men who receive highly purified factor VIII concentrates are lower than those predicted by use of current prescribing recommendations.

Management of individuals with Parkinson's disease: rationale and case studies

In this article, we present a systematic approach to physical therapy management of individuals with Parkinson's disease. This approach is based on a model that relates knowledge of the underlying pathology of the disease to impairments and disability. We discuss use of the model to evaluate, interpret, and treat impairments and disabilities of the patient with Parkinson's disease. We emphasize the relative influence of impairments that arise directly from the neuroanatomical pathology and those that arise indirectly through subsequent musculoskeletal alterations. We illustrate the use of the model in setting goals and in developing a treatment program. Two case studies are presented to illustrate the application of this approach to specific patient care. These case studies suggest the efficacy of physical therapy initiated early in the disease process. The first case study illustrates improvements of balance, gait, and functional movement made by an individual who was not yet receiving medication for Parkinson's disease. The second case study illustrates improvements of balance, gait, and functional movement made by an individual who was already receiving medication for the disease. These case studies illustrate the dramatic improvements that can be achieved in the patient with Parkinson's disease.

A model for multisystem evaluation treatment of individuals with Parkinson's disease

In this article, we present a model of Parkinson's disease based on pathophysiology, impairments, and disabilities. The model provides a format for deciding what to assess, for interpreting assessment findings, and for deciding which impairments can be corrected by physical therapy intervention and which cannot. From the model, we can predict effective treatment approaches. We can also use the model to identify specific research questions related to the efficacy of physical therapy intervention.

A model for multisystem evaluation, interpretation, and treatment of individuals with neurologic dysfunction

We have presented a model that can be used to organize current concepts of neuroanatomy, neurophysiology, and motor control theory into a clinically relevant context. This model can be used to postulate the causal relationship among pathology, impairments, and disabilities. Knowledge of the insult often provides predictive information regarding stability of the disability, progression of the disease, and possibly recovery. Knowledge of neuropathology should guide the clinician regarding the types of impairments that are expected. Thus, by knowing the type and location of the lesion, the clinician already has a perspective regarding which evaluative tests should be emphasized and what treatment strategies will be most effective. In the absence of known pathology, knowledge of motor control theory, neuroanatomy, and neuropathology can still help the clinician make educated judgments regarding the interrelationship of the patient's impairments. In this model, we separate impairments that result directly from neuropathology and those that arise indirectly to help the clinician keep the total patient in perspective and to focus intervention. This separation emphasizes the applicability and limitations of motor control theories in the treatment of neurologically impaired individuals. Motor control theory helps to identify the relationship between direct impairments and their likely consequences; motor control theory does not address the very real issue of impairments that arise indirectly in systems such as the musculoskeletal and cardiopulmonary systems. Impairments that occur as a composite effect of multiple causes are identified as a separate category. Some of the causes of these impairments can often be addressed by physical therapy intervention, and some cannot.(ABSTRACT TRUNCATED AT 250 WORDS)

Cerebral hemisphere asymmetry in CT and functional recovery from hemiplegia

Cerebral hemispheric asymmetries were assessed in relation to motor and functional recovery in nine patients with stroke. All were globally aphasic, assuring similar location and extent of lesion. Initial motor and functional ability were appraised from medical records and compared with neurologic and functional outcome. Frontal and occipital hemispheric widths and lengths were determined from CT. Patients were classified into three groups on the basis of mean combined asymmetry for width (typical asymmetry, atypical asymmetry, and equal symmetry). Patients with the most atypical cerebral asymmetries showed greater recovery than patients in other groups. Two patients with atypical mean occipital asymmetry (width) fared best functionally, whereas the patient who showed the greatest motor recovery had the most atypical mean occipital asymmetry (width). Cerebral asymmetries may contribute to recovery after stroke.

Headache in cerebral embolic disease

A patient is presented who had severe headache and then developed a stuttering course of clinical neurological deficits. Arteriography demonstrated an ipsilateral proximal middle cerebral embolus. With recurrence of symptoms, repeat arteriography showed another, more proximal embolus with areas of distal occlusion. The headache probably occurred when the embolus became lodged in a pain sensitive cerebral vessel at the base of the brain. The subsequent stuttering neurological deficits were due to fragmentation of the embolus as well as recurrence.

Computerized tomography in the management of intracranial bleeding in hemophilia

Computerized tomography was used to evaluate the severity of six episodes of suspected intracranial bleeding in four patients with hemophilia. In all instances the CT scan rapidly provided information on the extent and location of the intracranial hemorrhage. Results of the initial scan provided a rational basis for therapy, and subsequent scans were a noninvasive means of evaluating the effects of treatment. If available, computerized tomography is a valuable aid in the management of the hemophiliac patient with intracranial bleeding.