The use of a co-design model in improving timely bleed reporting by adults with haemophilia living in the Auckland region of New Zealand

Many adult patients diagnosed with phenotypically moderate and severe haemophilia living in the Auckland region of New Zealand do not report bleeding episodes within a timeframe that allows for optimal assessment and management. This can result in poor clinical outcomes for patients and poor oversight of the use of expensive clotting factor concentrates. Our goal was to improve both the number and speed at which bleeding episodes were reported to our centre, improving access to care and clinical oversight of the use of expensive factor concentrates and aiding the development of a care partnership with patients. We worked with 70 adult PWH living in the Auckland region of New Zealand with moderate and severe haemophilia A and B. Over a 5-month period between March and July 2013 we used a co-design model to develop and implement a range of strategies to improve the timing and frequency of bleed reporting. Mean bleed reporting time was reduced threefold, with a threefold increase in the number of bleeds reported per month. We reduced the number of bleeding episodes reported outside of a prespecified 48-h time limit by 68%. We significantly improved bleed reporting and time to report, indicating improved access to our services, improved clinical oversight and improved accountability to our national funder. We have achieved a care partnership and a reduction in factor consumption for the study population without compromising the quality of care they receive.

Consensus guidelines for warfarin therapy. Recommendations from the Australasian Society of Thrombosis and Haemostasis

The anticoagulant effect of warfarin should be kept at an international normalised ratio (INR) of about 2.5 (desirable range, 2.0-3.0), although a higher level may be better in a few clinical conditions. The risk of bleeding increases exponentially with INR and becomes clinically unacceptable once the INR exceeds 5.0. Warfarin therapy should be continued for around six weeks for symptomatic calf vein thrombosis, and for 3-6 months after proximal deep vein thrombosis (DVT) that occurs after surgery or limited medical illness. Therapy for six months or longer could be considered for DVT occurring without an obvious precipitating factor, proven recurrent venous thromboembolism (VTE), or if there are continuing risk factors. Oral anticoagulants prevent ischaemic stroke in atrial fibrillation (AF). Maximum efficacy requires an INR > 2.0, but some benefit remains at an INR of 1.5-1.9. Patients aged over 75 years are at greatest risk of intracranial bleeding during warfarin therapy for AF, and the target INR may be reduced to 2.0-2.5, or perhaps as low as 1.5-2.0, in such patients. Warfarin should be withheld if it is more likely to cause major bleeding than to protect from stroke (e.g., in young people with isolated AF where the annual baseline risk of stroke is < 1%). In patients with AF, aspirin is less effective than warfarin (much less effective after such patients have had a stroke or transient cerebral ischaemia). In people with prosthetic heart valves, an INR of 2.5-3.5 is probably sufficient for bileaflet or tilting disc valves, but a higher target INR is necessary for caged ball or caged disc valves. The addition of aspirin (100 mg/day) further decreases the risk of embolism but increases the risk of gastrointestinal bleeding.

The use of central venous catheters (portacaths) in children with haemophilia

The experience with central venous implantable devices (portacaths) has been reviewed in children attending the Auckland Hospital Haemophilia Centre. Fourteen children had 23 portacaths inserted. Thirteen had severe Haemophilia A, of whom five had high responding inhibitors to factor VIII. All the children were HIV negative. Ages ranged from 4 months to 13 years at the time of initial placement and 12 were under 5 years. Indications for portacath placement included primary and secondary prophylaxis, induction of immune tolerance, prophylactic therapy post intracranial haemorrhage and poor venous access. Catheter-related infections occurred in 48% of cases. Staphylococcal species were the most common organisms isolated followed by gram-negative bacilli. 63% of the infections were successfully cleared with antibiotics. Haematoma formation occurred in 17% of catheters, primarily in patients who had high factor VIII inhibitor levels. Mechanical problems including blockage, leakage and extrusion of the portacath occurred less frequently (13%). The significant rate of infection in this immunocompetent population is consistent with other reports. Despite the obvious benefits of portacaths this complication is potentially serious and causes appreciable morbidity. In contrast, bleeding complication rates were relatively low.

Treatment of venous thrombosis with intravenous unfractionated heparin administered in the hospital as compared with subcutaneous low-molecular-weight heparin administered at home. The Tasman Study Group

BACKGROUND

An intravenous course of standard (unfractionated) heparin with the dose adjusted to prolong the activated partial-thromboplastin time to a desired length is the standard initial in-hospital treatment for patients with deep-vein thrombosis, but fixed-dose subcutaneous low-molecular-weight heparin appears to be as effective and safe. Because the latter treatment can be given on an outpatient basis, we compared the two treatments in symptomatic outpatients with proximal-vein thrombosis but no signs of pulmonary embolism.

METHODS

We randomly assigned patients to adjusted-dose intravenous standard heparin administered in the hospital (198 patients) or fixed-dose subcutaneous low-molecular-weight heparin administered at home, when feasible (202 patients). We compared the treatments with respect to recurrent venous thromboembolism, major bleeding, quality of life, and costs.

RESULTS

Seventeen of the 198 patients who received standard heparin (8.6 percent) and 14 of the 202 patients who received low-molecular-weight heparin (6.9 percent) had recurrent thromboembolism (difference, 1.7 percentage points; 95 percent confidence interval, -3.6 to 6.9). Major bleeding occurred in four patients assigned to standard heparin (2.0 percent) and one patient assigned to low-molecular-weight heparin (0.5 percent; difference, 1.5 percentage points; 95 percent confidence interval, -0.7 to 2.7). Quality of life improved in both groups. Physical activity and social functioning were better in the patients assigned to low-molecular-weight heparin. Among the patients in that group, 35 percent were never admitted to the hospital at all, and 40 percent were discharged early. This treatment was associated with a mean reduction in hospital days of 67 percent, ranging from 29 percent to 86 percent in the various study centers.

CONCLUSIONS

In patients with proximal-vein thrombosis, treatment with low-molecular-weight heparin at home is feasible, effective, and safe.

Transformation of essential thrombocythaemia to T cell acute lymphoblastic leukaemia

Leukaemic transformation of essential thrombocythaemia is a rare event and is usually associated with previous treatment with either alkylating agents or radioactive phosphorous. We describe a patient with essential thrombocythaemia who developed an acute leukaemia of T cell phenotype following hydroxyurea therapy. The T cell phenotype of the blasts suggests the target cell for leukaemic transformation was a pluripotential stem cell.

Comparison of tests for the lupus anticoagulant and antiphospholipid antibodies in systemic lupus erythematosus

A variety of laboratory assays are used to screen for the presence of the lupus anticoagulant. Six commonly used coagulation tests, and the ELISA assay for antiphospholipid antibody using three different substrate phospholipids, have been evaluated in 110 patients with systemic lupus erythematosus or lupus-like disease. One or more coagulation assays was abnormal in 41% (45/110) of the patients. No individual test detected more than 78% of these abnormalities, indicating that a single phospholipid based coagulation test cannot be used to screen for a possible lupus anticoagulant. A combination of Actin FSL, DTTA and DRVVT detected all the abnormalities. The most sensitive two-test combination was Actin FSL and DRVVT. Approximately half (56%) of the patients with a positive clotting test had an abnormal antiphospholipid antibody assay. A similar proportion (58%) of the aPL positive patients had a prolonged coagulation test. The marked discordance between the coagulation assays and a positive antiphospholipid antibody test further complicates the laboratory definition of this abnormality, at least in patients with systemic lupus erythematosus.

Hb Howick [beta 37(C3)Trp-->Gly]: a new high oxygen affinity variant of the alpha 1 beta 2 contact

Hb Howick or beta 37(C3) Trp-->Gly is a newly described hemoglobin variant found in an adult male. Hematological data and stability by the isopropanol stability test were normal. The abnormal variant comprised 29% of total hemoglobin and migrated in the Hb D position on cellulose acetate at pH 8.6, and in the Hb F position on citrate agar (pH 6.0). Oxygen dissociation studies on the whole blood showed the variant to have a higher oxygen affinity than normal, with a P50 of 19.8 mm Hg (normal, 26 mm Hg). There were also significant differences in the saturation curve. The variant showed a reduced Bohr effect which was manifested as very high oxygen affinity at low pH and saturation. The beta 37 residue is an alpha 1 beta 2 contact site and the substitution of the tryptophan for a glycine would be expected to result in a destabilization of the deoxy-hemoglobin form because of the reduced number of hydrogen bonds, salt bridges and van der Waal contacts between the alpha 1 and beta 2 chains.

Haemoglobin Manukau beta 67[E11] Val-->Gly: transfusion-dependent haemolytic anaemia ameliorated by coexisting alpha thalassaemia

Haemoglobin Manukau (beta 67 Val-->Gly) is a novel haemoglobin variant presenting in two brothers as nonspherocytic haemolytic anaemia which became transfusion dependent by 6 months of age. The severity of clinical expression seems to be modulated by coexisting alpha thalassaemia: the severely affected children have a normal complement of alpha globin genes with an unusual genotype (-alpha 3.7/alpha alpha alpha 3-7), while their father, who carries the abnormal gene with minimal symptoms, has homozygous alpha+ thalassaemia (-alpha 3.7/-alpha 3.7). Another unusual feature of this case is the association of the beta 67 Val-->Gly mutation with modification of beta 141 Leu to a residue (believed to be hydroxyleucine) that is not detected by standard amino acid analysis. This finding offers an explanation for the previous report of an association of another mutation at this site (Hb Sydney beta 67 Val-->Ala) with Hb Coventry (deletion of beta 141 Leu).

Deep vein thrombosis prophylaxis: a survey of current practice in Australia and New Zealand

A survey of current practice for deep vein thrombosis (DVT) prophylaxis was undertaken in Australia and New Zealand. The most common indications for prophylaxis were a history of thrombo-embolism, the type and length of surgery and obesity. Prophylaxis was used in 65% of patients having hip surgery and in 39% undergoing knee surgery. In general surgery the corresponding rate was around 67% for colorectal surgery, hepatobiliary, upper gastrointestinal and major abdominal vascular surgery. Apart from open-heart cardiothoracic surgery (66%), use in other specialties was less than 50%. Physical methods (anti-embolism stockings, calf stimulation and calf compression devices) were most commonly used for prophylaxis (46%) with heparin being used by 40%. The main side effect reported with heparin was bleeding (18%). The estimated incidence of DVT and pulmonary embolus (PE) was 2.8 and 0.4% for general surgery, 2.7 and 0.7% for orthopaedic surgery and 6.6 and 1.3% for hip surgery. Intravenous heparin followed by oral anticoagulants was the most commonly used treatment for established DVT and nearly all respondents used intravenous heparin and oral anticoagulants for treatment of PE. Venography was the favoured objective test for diagnosing DVT. The principal reason for considering a change in prophylactic policy was the potential availability of an agent with increased efficacy and a reduced incidence of haemorrhagic complications.

Reduced synthesis of tissue plasminogen activator by vascular endothelium during acute myocardial infarction

We measured levels of tissue plasminogen activator (t-PA) antigen in 100 patients within six hours of the onset of acute myocardial infarction, in 34 patients with chronic angina but no recent infarction, and in 36 normal subjects. We also assayed von Willebrand factor in the acute patients and in the normal subjects. Measurements were repeated in 40 acute patients at three weeks after myocardial infarction. Although resting levels of t-PA antigen were not significantly different from normal during myocardial infarction, the capacity of the vascular endothelium to release t-PA after five minutes of venous occlusion was impaired (p less than 0.01). The acute phase vessel wall release of von Willebrand factor was increased during acute infarction (p less than 0.01). We conclude that impairment of t-PA production is associated with acute coronary thrombosis, although it is not possible to differentiate between a causative role or a secondary response due to exhaustion of the t-PA producing mechanism.

Haemophilia management: the application of DNA analysis for prenatal diagnosis

The haemophilias are chronic debilitating disorders which cause significant morbidity for the patient and may affect the whole family. An important part of the management of these disorders is the provision of accurate carrier detection and prenatal diagnosis in conjunction with genetic counselling services. We report the results of carrier detection and prenatal diagnosis obtained over a two year period using recombinant DNA techniques. Eighty-seven individuals from 15 families with either haemophilia A or B have been evaluated using informative intragenic factor VIII or IX restriction fragment length polymorphisms. Chorionic villi biopsies for prenatal diagnosis have been performed in four subjects, revealing two female carriers, one normal male, one normal of unknown sex and one haemophiliac male. The use of genotypic diagnosis of haemophilia A and B, in conjunction with conventional assays, is now a routine part of the modern management of haemophilia and many other inherited disorders.

Restriction fragment length polymorphisms associated with the factor VIII and factor IX genes in Polynesians

New Zealand Maoris (72 X chromosomes) have been compared with Pacific Island Polynesians (121 X chromosomes) and Caucasian New Zealanders (51 X chromosomes) as a control group to determine the allelic frequency of six RFLPs associated with the genes for two X linked diseases (haemophilia A and haemophilia B). RFLPs examined were BclI, XbaI, and BglI within the factor VIII gene, the factor VIII extragenic TaqI system, and the factor IX intragenic TaqI and XmnI sites. The information obtained facilitates the design of strategies for both carrier detection and prenatal diagnosis of haemophilia A within these groups. Strong linkage disequilibrium was observed between the factor VIII BclI and XbaI sites in Polynesians. Genetic counselling for Polynesians with haemophilia B continues, however, to rely on phenotypic diagnosis. The RFLP data from the two separate loci on the X chromosome in Polynesians show similarities with Chinese and Japanese populations, reinforcing theories of an early Polynesian ancestry originating in east Asia.

Haemophilia B Leyden arising de novo by point mutation in the putative factor IX promoter region

Haemophilia B Leyden is characterized by severe factor IX deficiency during childhood with partial resolution at puberty or following the administration of anabolic steroids. The disorder has recently been associated with point mutations in the putative factor IX promoter region, which contains an imperfect direct repeat spanning a possible start site of transcription. We have identified a T to C transition at position +8 in the promoter region of a patient with the haemophilia B Leyden phenotype. A mutation at this site has not been previously reported and occurs within the repeat consensus sequence in the transcribed but untranslated portion of the gene. There is no family history of haemophilia and sequence analysis of his mother and other family members indicates that the mutation has arisen de novo in this patient. This observation provides further support for a causal relationship between point mutations in the presumptive promoter region of the factor IX gene and the Leyden phenotype.

A double-blind randomized placebo controlled trial of thromboprophylaxis in major elective general surgery using once daily injections of a low molecular weight heparin fragment (Fragmin)

The safety and efficacy of the low molecular weight heparin fragment (Fragmin) administered as a single daily injection of 2,500 anti Xa units has been evaluated in 183 patients undergoing major elective general surgery. The study was double-blinded and placebo controlled. The active agent, or placebo, was given subcutaneously with the preoperative medication and continued postoperatively for 5-9 days. Ninety five patients received Fragmin and 88 were randomized to receive the placebo. The clinical characteristics of the two treatment groups were similar. Fragmin significantly reduced the incidence of deep venous thrombosis, as detected by a positive 125I fibrinogen leg scan, relative to the placebo treated patients (4/95, 4.2% v. 14/88, 15.9%; p = 0.008). The thrombotic events occurred predominantly (73%) amongst patients with malignancy. Haemorrhagic endpoints necessitating discontinuation of the trial treatment were 4% in each group. No severe adverse reactions or drug related deaths occurred. These results indicate that 2,500 anti Xa units of Fragmin given only once daily is effective thromboprophylaxis for patients undergoing major elective abdominal surgery.

Clinical manifestations of the thrombocytopenia and absent radii (TAR) syndrome

Six patients with the classical features of the TAR syndrome were diagnosed at birth. In one case an older sibling was also affected. The characteristic features of foreshortened forearms and radially deviated hands were noted in all cases at presentation and confirmed radiologically. With one exception skeletal abnormalities of the lower limbs were also present. Varying degrees of thrombocytopenia were present at birth with three of the five patients having platelet counts below 50 x 10(9)/L. Bone marrow examination was performed in two patients and revealed an absence of normal megakaryocytes. Two patients with severe thrombocytopenia had bleeding complications during infancy requiring transfusion support. Severe gastroenteritis occurred in two patients, in one of whom it was attributed to cow's milk intolerance. In all patients the platelet count has risen progressively since birth. Orthopedic surgical procedures have been performed without hemorrhagic complications.

Etiology, prognosis, and hemostatic function after cerebral infarction in young adults

We retrospectively evaluated 66 patients younger than 40 years of age who presented with acute nonhemorrhagic cerebral infarction (n = 63) or transient ischemic attacks (n = 3) to determine the possible etiology and long-term outcome at a mean follow-up interval of 3 years after initial presentation. A probable cause for the stroke was identified in 24 patients (36%); this group included one woman with a history of recurrent spontaneous abortions and a positive test for the presence of the lupus anticoagulant. We performed detailed hemostatic investigations at follow-up in 38 (90%) of the remaining 42 patients in whom the cause of the stroke was unknown or uncertain; results of the basic hemostatic screening tests (including that for fibrinogen) were uniformly normal. All 38 patients demonstrated a normal fibrinolytic response as measured by tissue plasminogen activator release to a standard venous occlusion stress test; concentration of the inhibitor of tissue plasminogen activator was not increased. No abnormalities in the concentrations of the inhibitory proteins C or S or antithrombin III were identified, and none of the 38 patients had evidence of a lupus anticoagulant. Neurologic recovery was complete or the residual disability mild in 46 of 59 (78%) patients. Overall prognosis was excellent and independent of whether a precipitating factor for the stroke could be identified.

Influence of heat treatment on FVIII:C recovery from freeze dried cryoprecipitate

A standard lyophilised triple cryoprecipitate preparation, stabilised by the addition of Synthamin 17, was heat treated at 60 degrees C for 48 hours. The total protein content, factor VIII concentration, and factor VIII recovery were not affected by the heat treatment procedure. Heat treatment did not influence the reconstitution characteristics of the freeze dried preparation and there were no side effects during or after administration. The mean in vivo rise of factor VIII from infused heat treated triple cryoprecipitate was 2.5 (SD 0.9)%/unit/kg with a half life of 13.1 (3.1) hours. These results compare favourably with those obtained using non-heated triple cryoprecipitate. Cryoprecipitate can be heat treated without adversely influencing factor VIII recovery, and the ability to prepare a heat treated cryoprecipitate means that a small pool high yield factor VIII preparation can again be used in routine clinical practice.

Comparative separation of human plasma proteins on polysulphated chromatographic media

Polysulphated chromatographic media, particularly Heparin Sepharose, are generally used to purify a variety of different plasma proteins. Heparin Sepharose, dextran sulphate Sepharose and sulphated dextran are compared with two recently available sulphated cellulose chromatographic media. The potential influence of structural features of different polysaccharides on the interaction with selected plasma proteins has been evaluated with the particular objective of developing an alternative medium for the preparation of specific therapeutic factor concentrates. The studies indicate that the degree of sulphation of the matrix is an important but not a critical determinant for resolution of factors IX and X. Despite large differences in the carbohydrate structure of the matrices, the new sulphated cellulose gel 5.2 had a total protein capacity and specific binding profile comparable to Heparin Sepharose. The sulphated cellulose which is competitively priced, and has excellent stability, is a potential alternative to Heparin Sepharose especially for larger scale industrial processing of factor IX concentrate.

Controlled pore glass factor VIII concentrate: influence of heat treatment

A high purity factor VIII concentrate prepared by controlled pore glass (CPG) adsorption chromatography was stabilized with an amino acid mixture, lyophilized and heat treated at 60 degrees C for 72 h. Heat treatment of the freeze-dried concentrate resulted in less than 10% further loss of factor VIII activity, with a final yield of factor VIII from starting plasma of 25%. Heat treatment did not alter product reconstitution, nor appearance, and clinical experience has been favourable. Following infusion into 9 hemophiliac patients the mean ex vivo recovery (1.03) was not significantly different from that obtained with the non-heated CPG concentrate. The mean half lives (T1/2) of both heated and non-heat treated material were identical. Stabilization and heat treatment of CPG does not influence the excellent ex vivo recovery, nor therapeutic response, and is not associated with other adverse side effects.

Heat treated New Zealand factor IX concentrate: comparison with Prothrombinex in patients with haemophilia B

Factor IX concentrates, prepared by standard chromatographic techniques, are used primarily to treat patients with congenital factor IX deficiency. A local factor IX containing concentrate has now been prepared and heat treated. Following heat treatment, and reconstitution, the potency is 280 units per vial. The preparation, HNZFIX, has been compared with the currently available factor IX concentrate Prothrombinex. Following administration into patients with haemophilia B, ex vivo factor IX recovery and half life response have been compared for the two products. The mean recovery values were identical with an average 17 units per litre rise in factor IX activity obtained for each unit of factor IX concentrate administered per kg of body weight. For both products recovery measured as the K ratio was approximately 75% (0.75). The plasma half life responses were 17 and 22.2 h for the HNZFIX and PTX respectively. No unexpected side effects occurred with the HNXFIX which met all the British Pharmacopeia requirements for a therapeutic concentrate.

Evaluation of therapeutic decisions in patients with suspected pulmonary embolism and a low probability lung scan: application of Bayes' Theorem

Three hundred and one consecutive lung scans were reviewed to determine the frequency of the different ventilation perfusion scan patterns and their use in the management of suspected pulmonary embolism. Based on the original report, an accurate diagnosis was possible in 99 patients (33%). Within this group pulmonary embolism was excluded by a normal lung scan in 35 (12%), and confirmed in 64 (21%) patients having a high probability pattern. There were 194 (64%) patients with a low probability scan, but in only 24 of these (12%) was venous thromboembolism objectively confirmed or excluded by additional investigations. Although the low probability scan is non-specific, the scan result was used as the sole objective test to determine therapy in 170 patients (56%). The clinical decision was to withhold anticoagulants in 143 patients and to treat 27 patients. Probability estimates using Bayes' Theorem have been applied to evaluate these management decisions.

Comparison of methods of plasma volume determination for dose calculation of factor VIII in patients with classic haemophilia

Plasma volumes have been measured in 12 patients with moderate or severe haemophilia A and compared with plasma volumes derived by calculation using a variety of commonly recommended formulae based on body weight with or without a correction for haematocrit. The mean plasma volume by measurement was 47 ml/kg. A calculated plasma volume using 42 ml/kg and a correction for haematocrit most closely approximated the measured results. The correlation coefficient was 0.9. Ex vivo factor VIII recoveries, following infusion of either lyophilised cryoprecipitate or NZFVIII (controlled pore glass preparation), were then determined based on the observed/expected response assuming different values for plasma volume. Mean recoveries of approximately 100% were associated with a 2.4% FVIII rise per unit/kg administered using cryoprecipitate. Ex vivo recoveries following NZFVIII exceeded 100% with mean values, depending on the technique used for plasma volume determination, up to 131%. Recoveries were not significantly affected by the plasma volume method used and all methods indicated that the labelled potency of NZFVIII is currently being underestimated by at least 20-30%.

In vivo activity of a new heparinoid

Org 10172 is a heparinoid prepared during the manufacture of porcine mucosal heparin. This compound has been compared with a standard commercial grade heparin in vitro and in vivo using experimental thrombosis and bleeding models in rabbits. Increasing doses of both the heparin and the heparinoid resulted in a similar prolongation of a Xa clotting time and the APTT, but the heparinoid had no effect on the thrombin clotting time over the concentration range 0-3.0 units/ml. Both preparations were antithrombotic using a stasis prophylaxis model but inhibition of thrombosis was independent of the ex vivo anti-Xa heparin levels achieved. Relative to heparin, the heparinoid failed to induce hemorrhage. A potential therapeutic advantage for Org 10172 as an antithrombotic agent for clinical use can be predicted.

Diagnostic efficacy of impedance plethysmography for clinically suspected deep-vein thrombosis. A randomized trial

Impedance plethysmography is an accurate noninvasive method to test for proximal vein thrombosis, but it is insensitive to calf-vein thrombi. We randomly assigned patients on referral with clinically suspected deep-vein thrombosis and normal impedance plethysmographic findings to either serial impedance plethysmography alone or combined impedance plethysmography and leg scanning (which has been shown to be essentially as sensitive as venography) and compared the long-term outcomes. During the initial surveillance, deep-vein thrombosis was detected in 6 of 311 patients (1.9%) tested by serial impedance plethysmography alone and in 30 of 323 patients (9.3%) (most with calf-vein thrombi) tested by the combined approach (p less than 0.001). During long-term follow-up, no patient died from pulmonary embolism; but 6 patients (1.9%; 95% confidence limits, 0.7% to 4.2%) tested by serial impedance plethysmography developed deep-vein thrombosis compared with 7 patients (2.2%; 95% confidence limits, 0.9% to 4.4%) tested by the combined approach. Serial impedance plethysmography used alone is an effective strategy to evaluate such symptomatic patients.

Lidocaine and the reduction of post-venographic pain

Venography remains the standard method for the diagnosis of deep venous thrombosis but it is invasive and frequently causes discomfort. A randomised double-blind study was performed to determine the efficacy of lidocaine in reducing pain and discomfort associated with venography. Sixty patients undergoing ascending venography received 40 mg of lidocaine (2 ml of 2% lidocaine mixed with 50 ml of contrast medium) in one leg and saline in the other. Assessment of pain was by a standard questionnaire administered by an investigator unaware of the sequence of administration of lidocaine or saline placebo. Twenty-four patients reported no difference in pain or discomfort between the two limbs. Of the 36 patients experiencing an overall difference in pain between the two legs, 12 reported more pain in the leg receiving lidocaine and 24 reported more pain in the leg receiving saline (p = 0.023). There were no significant side effects attributable to lidocaine. These results indicate that lidocaine is beneficial in reducing pain and discomfort associated with venography.

Strategies to diagnosis and screening of deep venous thrombosis and pulmonary embolism

The clinical diagnosis of venous thrombosis or pulmonary embolism is unreliable and must be confirmed by objective methods. The available objective diagnostic tests which have been evaluated for deep vein thrombosis and shown to be of value are venography, IPG, and (125I)-fibrinogen leg scanning. All these methods have certain disadvantages, but the potential advantages of accurate diagnosis using a combination of non-invasive tests as an alternative to venography are considerable. This approach is cost-effective, because it avoids unnecessary hospital admissions and reserves anticoagulant treatment for those in whom diagnosis of deep venous thrombosis is confirmed. Non-invasive techniques can also be used to screen high risk surgical patients for whom no inexpensive, effective, safe form of prophylaxis is available. The correct diagnostic approach in suspected pulmonary embolism remains to be established. The initial screening by perfusion lung scan with ventilation studies, followed by either the demonstration of pulmonary emboli with angiography, or the demonstration of peripheral deep venous thrombosis, is considered to be the safest approach.

Pulmonary angiography, ventilation lung scanning, and venography for clinically suspected pulmonary embolism with abnormal perfusion lung scan

Inherent contradictions in current diagnostic recommendations for pulmonary embolism have created considerable confusion and controversy. To resolve these contradictions, we did a prospective study of ventilation-perfusion scanning, pulmonary angiography, and venography in consecutive patients with clinically suspected pulmonary embolism and abnormal perfusion scans. Ventilation scanning increased the probability of pulmonary embolism in patients with large perfusion defects and ventilation mismatch, but a ventilation-perfusion match was not helpful in ruling out pulmonary embolism. Small perfusion defects with mismatch had neither sufficiently high nor low probability to be of diagnostic value. The observed frequency of proximal vein thrombosis (19% to 51%) and its association with the range of ventilation-perfusion defects have important implications for management of pulmonary embolism. Pulmonary angiography is required in combination with venography in most patients with perfusion abnormalities because the probability of pulmonary embolism is neither sufficiently high nor low to confirm or exclude pulmonary embolism.

Use of a new heparinoid as anticoagulant during acute haemodialysis of patients with bleeding complications

Org 10172, a new, natural heparinoid, was used as the sole anticoagulant in twelve patients with acute or acute-on-chronic renal failure, who underwent haemodialysis 55 times. All patients had either intercurrent bleeding or a high risk of severe haemorrhagic complications if given standard heparin therapy. After a single loading dose of 300-600 mg of Org 10172, plasma anti-Xa levels in the range 0.42 - 0.93 U/ml were achieved. All haemodialysis runs were completed without adverse side-effects. There were no haemorrhagic complications and deposition of 125I-fibrinogen on the renal dialysis membrane was successfully inhibited in the 4 patients in whom this was studied. Org 10172 seems to prevent thrombosis during renal haemodialysis. It may have a lower risk/benefit ratio than other anticoagulants, such as heparin, in patients at high risk of haemorrhagic complications undergoing haemodialysis.

The diagnosis of acute, recurrent, deep-vein thrombosis: a diagnostic challenge

Recurrent venous thrombosis presents a diagnostic challenge. Venography, impedance plethysmography and fibrinogen leg scanning all have potential limitations, and their role in this context has not been evaluated. We performed a prospective cohort study evaluating impedance plethysmography and leg scanning, plus venography, using outcome on long-term follow-up as the end point in 270 patients with clinically suspected recurrent deep-vein thrombosis. Anticoagulant treatment was withheld in the 181 patients negative by noninvasive testing and was given in patients positive by impedance plethysmography if leg scanning was positive or if intraluminal filling defects were detected by venography. The validity of this approach was tested by long-term follow-up. Three of 181 patients (1.7%) negative by noninvasive testing had a recurrence, compared with 18 of 89 (20%) with positive findings (p less than 0.001). Our objective diagnostic approach has high clinical utility; an objective rationale for withholding or giving treatment was established in 95% of patients.

Discordance between the anti-Xa activity and the antithrombotic activity in an ultra-low molecular weight heparin fraction

The relationship between the in vivo antithrombotic effect of heparin and ex vivo anti-Xa activity has been investigated using an animal thrombosis model. Three low molecular weight heparins were compared with the standard heparin from which they were fractionated. All four heparins showed a dose-dependent antithrombotic effect enabling the relative antithrombotic and anti-Xa activities to be compared over a dosage range. A correlation between ex vivo anti-Xa heparin levels and antithrombotic effect was demonstrated for the standard (MW 16,000), intermediate (MW 7,600) and low (MW 4,600) molecular weight heparins but not for the ultra-low molecular weight (MW 3,000) fraction. The lack of relationship between anti-Xa activity and inhibition of thrombosis for the very low molecular weight fraction indicates that a very high anti-Xa activity (measured in vitro or ex vivo) is not always predictive of in vivo antithrombotic efficacy. These findings suggest that other properties of low molecular weight heparins contribute to their antithrombotic effectiveness.

Comparison of the in vivo hemorrhagic and antithrombotic effects of a low antithrombin-III affinity heparin fraction

Antithrombin III (ATIII) affinity chromatography of commercial grade heparin yields fractions of high and low affinity for ATIII. In vitro, the high affinity fraction accounts for most of the anticoagulant effect while there is evidence that the low affinity material interferes with platelet function. We have studied the relative antithrombotic and hemorrhagic effects of low affinity heparin. The low affinity heparin fraction, specific activity 43 USP units/mg, was compared with standard heparin (150 USP units/mg) in rabbit experimental models. A residual 12.5% by weight of this low affinity heparin showed high affinity for ATIII. Inhibition of thrombosis in a stasis-hypercoagulability model was directly related to the weight (mg) of high affinity material in each of the heparins. In the bleeding model, when similar weights (mg) of high affinity material were infused, significantly more bleeding was demonstrated with the low affinity fraction which contained a 5-fold excess by weight of low affinity material. We have demonstrated that a low affinity heparin depleted of in vitro anticoagulant and in vivo antithrombotic activity significantly contributes to hemorrhage.

Serological complications of a major ABO incompatible bone marrow transplantation in a Polynesian with aplastic anemia

A 24-year-old, blood-group O Polynesian woman with multiple red blood cell antibodies received a group A, HLA-compatible, sex-matched bone marrow transplantation as treatment for severe aplastic anemia. High retransplantation titers of ABO isohemagglutinins were successfully reduced by repeated plasmaphereses. Despite gross in vitro incompatibility in the routine crossmatch, technetium-labelled red blood cell survival studies performed immediately prior to transplantation predicted that a small proportion of the donor erythrocytes would neutralize residual postplasmapheresis isoantibody. Donor marrow was subsequently infused without significant hemolysis. Although anti-A titers were low immediately posttransplantation, these rose progressively, approaching pretransplantation levels at the time of documented marrow engraftment at day 18. One week later the bone marrow graft was rejected. Retransplantation was successfully performed using marrow from an ABO compatible, sex-mismatched sibling donor. Radioisotopic studies were helpful in evaluating donor-recipient red blood cell incompatibility during the ABO incompatible transplantation, and again at retransplantation in the presence of circulating isoantibody to donor red blood cells. High levels of ABO isoagglutinins prior to plasmapheresis and rapidly rising titers posttransplantation may have predicted bone marrow graft rejection in this patient.

Improved survival from acute lymphoblastic leukemia in adolescents and adults

Nineteen adult patients with acute lymphoblastic leukemia were treated with combination chemotherapy to induce remission in the period from 1971 to 1979. Those patients achieving remission received intensive post-remission therapy with central nervous system (CNS) prophylaxis, followed by two-drug maintenance therapy, and reinduction courses of chemotherapy every six months. Remissions were achieved in 17 of the 19 patients (89%). Twelve patients (63%) are alive, 11 currently in complete remission. Two patients who experienced relapses in recent months have successfully undergone transplantation with allogeneic marrow from sex-matched, HLA-compatible sibling donors. The median survival and median duration rates of first remissions have not yet been reached, but to date are 36+ months and 29+ months, respectively with a predicted five-year survival rate of 61%. These results not only are significantly better than those achieved in the years 1968 to 1971 in our institution, but also are superior to others reported in the world medical literature. The combination of optimal treatment protocols with allogeneic marrow transplantation for patients with poor prognoses is expected to improve the survival of adult patients even further in the next decade.

Clinical experience with arginine vasopressin (DDAVP) in von Willebrand's disease and mild haemophilia

The use of 1 deamino-8-D-arginine vasopressin (DDVAP), is reported in seven patients with von Willebrand's disease and mild haemophilia undergoing elective surgery. There were no haemorrhagic complications, and both the quality of the clot formed and the rate of healing appeared entirely normal in all patients. No patient received blood products. Local burning pain due to paravenous leakage at the infusion site in a single patient, and transient facial flushing in another were the only side effects encountered. In addition to the anticipated rise in F.VIII:C and F.VIIIR:Ag, shortening of the bleeding time was observed in all five patients with von Willebrand's disease receiving DDAVP. Three additional patients who received intranasal DDAVP showed an inconsistent response in the laboratory parameters measured.

Bone marrow transplantation in a child with acute lymphoblastic leukaemia

A caucasian female infant with acute lymphoblastic leukaemia in second remission received a bone marrow transplantation. Engraftment was confirmed at 14 days following infusion of bone marrow from a sex-matched, ABO and HLA compatible sibling. 171 days posttransplantation the patient is clinically well and in haematological remission. A mild transient skin rash and hepatocellular disturbance, the only manifestations of graft versus host disease, responded successfully to high dose prednisone.

Hemoglobin Volga, beta 27 (B9) Ala replaced by Asp: functional and clinical correlations of an unstable hemoglobin

Hb Volga (beta 27 Ala replaced by Asp) on the basis of physical tests is only a mildly unstable hemoglobin yet it is associated with a gross reticulocytosis. This is partly explicable by an increased oxygen affinity with a compensating erythrocytosis but there is also brisk hemolysis. It is not certain that this hemolysis is due to precipitation of the hemoglobin as in vitro inclusion body formation is not remarkable and there is no evidence of preferential proteolysis of the abnormal subunits, at least in the reticulocytes. There is increased autoxidation and it may be the consequence of this that is the prime cause of hemolysis.