Israel Medical Association Journal

Background: Oral anticoagulation with warfarin can lead to life-threatening events as a result of either over-anticoagulation or undertreatment. One of the main contributors to an undesirable warfarin effect is the need to adjust its daily dose for a specific patient. The dose is adjusted empirically based on the experience of the clinician, a method that is often imprecise. There is currently no other well-accepted method for predicting the maintenance dose of warfarin.

Objective: To describe the application of an artificial neural network to the problem of warfarin maintenance dose prediction.

Methods: We designed a neural network that predicts the maintenance dose of warfarin. Data on 148 patients attending a large anticoagulant clinic were collected by file review. Using correlational analysis of the patients' data we selected the best input variables. The network was trained by using the back-propagation algorithm on a subset of our data and the results were validated against the rest of the data. We used a multivariate linear regression to create a comparable model.

Results: The neural network generated reasonable predictions of the maintenance dose (r = 0.823). The results of the linear regression model were similar (r = 0.800).

Conclusion: Neural networks can be applied successfully for warfarin maintenance dose prediction. The results are promising, but further investigation is needed.
 

Background: Pulmonary disease is the most frequent cause of morbidity and mortality in cystc fibrosis patients. New techniques such as non-invasive positive pressure ventilation have resulted in prolongation of life expectancy in CF[1] patients with end-stage lung disease.

Objectives: To determine the role of NIPPV[2] in CF patients awaiting lung transplantation.

Methods: Between 1996 and 2001 nine CF patients (5 females) with end-stage lung disease were treated with bi-level positive airway pressure ventilation in the "spontaneous" mode.

Results: The patients' mean age at initiation of BiPAP[3] was 15 years (range 13–40 years) and the mean duration of BiPAP usage was 8 months (range 3–16 months). Four patients underwent successful lung transplantation, three patients died while awaiting transplantation, and the remaining two are still on NIPPV while waiting for transplantation. Patients' body mass index increased significantly (P < 0.05) during BiPAP therapy (from 16.1 to 17.2 kg/m²). Blood pH, p_aCO₂, and bicarbonate improved significantly (from 7.31 to 7.38, 90.8 to 67.2 mmHg, and 48.9 to 40.3 mEq/L, respectively). Pulmonary function tests were not affected by BiPAP usage. The patients experienced a significant alleviation in morning headaches and improvement in quality of sleep (P < 0.003). There were no major complications during BiPAP usage.

Conclusions: We demonstrated that long-term NIPPV can stabilize and improve physiologic parameters such as ventilation, arterial blood gases and body mass index, as well as subjective symptoms such as sleep pattern, daily activity level, and morning headaches in CF patients with end-stage lung disease. Further prospectively controlled studies are needed to evaluate the potential of BiPAP therapy and its influence on morbidity and mortality in the post-lung transplantation period.

Background: Transmission of Pseudomonas aeruginosa among cystic fibrosis patients attending health camps has been reported previously.

Objectives: To determine the transmission of P. aeruginosa among CF[1] patients during three winter camps in the Dead Sea region in southern Israel.

Methods: Three consecutive CF patient groups were studied, each of which spent 3 weeks at the camp. The patients were segragated prior to camp attendance: patients who were not colonized with P. aeruginosa constituted the first group and colonized patients made up the two additional groups. Sputum cultures were obtained upon arrival, at mid-camp and on the last day. Environmental cultures were also obtained. Patients were separated during social activities and were requested to avoid social mingling. Isolates were analyzed by antibiotics susceptibility profile and by pulsed field gel electrophoresis.

Results: Ninety isolates from 19 patients produced 28 different fingerprint patterns by PFGE[2]. Isolates from two siblings and two patients from the same clinic displayed the same fingerprint pattern. These patients were already colonized with these organisms upon arrival. Two couples were formed during the camp, but PFGE showed no transmission of organisms. All other patients' isolates displayed unique fingerprint patterns and were distinguishable from those of other attendees, and none of the P. aeruginosa-negative patients acquired P. aeruginosa during camp attendance. Environmental cultures were negative for P. aeruginosa.

Conclusions: We were unable to demonstrate cross-infection of P. aeruginosa among CF patients participating in health camps at the Dead Sea who were meticulously segregated.

Histiocytosis of childhood is characterized by localized or generalized proliferation of cells of the mononuclear phagocyte system and the dendritic cell system. In patients with Langerhans cell histiocytosis, the orbita is the most involved site encountered in ophthalmic practice, usually as a lytic lesion in the zygomaticofrontal suture. Patients usually present with acute or chronic periorbital swelling. Electron microscopic findings of Birbeck granules and positive staining for CD1 antigenic determinant confirm the diagnosis.

Background: In developed countries, the incidence of Sydenham’s chorea, a major sign of rheumatic fever has declined, but outbreaks are still encountered worldwide.

Objectives: To report the characteristics of a cohort of SC[1] patients in the Jerusalem area.

Methods: We conducted a prospective assessment of rheumatic fever and SC between 1985 and 2002. The diagnosis of rheumatic fever was based on the revised Jones criteria. Other etiologies of chorea were excluded. Recurrence was defined as the development of new signs, lasting more than 24 hours and separated by a minimum of 2 months from the previous episode. Patients were followed for 1 to 14 years following the initial SC episode, and at least one year after recurrence.

Results: Among 180 children with rheumatic fever, 24 had SC. Most of them came from large families of Ashkenazi origin. In 19 patients (79%) the chorea was associated with other rheumatic fever signs, while 5 had pure chorea. Due to the systematic use of two-dimensional color Doppler echocardiography, cardiac involvement was detected in 75% of the patients. Ten patients (42%, 7 females) developed 11 recurrent episodes of chorea 3 months to 10 years after the initial episode. At recurrence, chorea was the sole rheumatic sign in all nine patients who recurred once. None of the patients had persistent chorea.

Conclusions: SC is still prevalent in the pediatric population of Jerusalem, and may recur years later. Recognition of the disease and adequate treatment is necessary.

Background: The management of diabetes in preschool children poses unique difficulties for both the families and the medical team.

Objective: To test the feasibility and safety of insulin pump therapy in the 1–6 year age group in order to improve quality of life and metabolic control.

Methods: The study group comprised 15 type 1 diabetic children aged 1–6 years old (mean ± SD, 3.8 ± 1.2 years) from three diabetes centers. Insulin pump therapy was applied for 12 months. Data, including insulin dose, hemoglobin A1c, hypoglycemic events, as well as scores on the Diabetes Quality of Life Measure Questionnaire and the Diabetes Treatment Satisfaction Questionnaire, were collected and compared with the multiple daily injections treatment prior to entry into the study.

Results: HbA1c[1] was measured at the beginning of the study and at 2, 4, 8 and 12 months later; the respective levels (mean ± SD) were 8.82 ± 0.98, 8.45 ± 1.05, 8.37 ± 0.85, 8.32 ± 0.71, 8.18 ± 0.90%. HbA1c measurements after 12 months were significantly lower than at the beginning of the study (P < 0.05). There were no significant differences in insulin dose and the total number of hypoglycemic events. In both the DQOL[2] and DTSQ[3] scales there were significant differences in scores in favor of the insulin pump period (43.7 ± 8.0 versus 33.7 ± 7.9, P < 0.001; and 10.9 ± 2.3 versus 14.5 ± 2.3, P < 0.001), respectively.

Conclusions: For very young diabetic children, insulin pump therapy improves quality of life and is feasible and safe. It should be considered as an optional mode of therapy for this age group.

Background: The ischemic “steal” syndrome complicates angio-access in a growing number of hemodialysed patients. Until now, operative attempts (fistula ligation or banding) to treat this problem have met with only limited success.

Objective: To assess the results of DRIL (distal revascularization-interval ligation) procedure in treating the “steal” syndrome.

Methods: A retrospective review (1996–2002) was conducted of all 11 patients who underwent the DRIL[1] procedure in two tertiary care hemodialysis units.

Results: Two patients were excluded because of inadequate medical documentation. All of the nine patients remaining suffered from overt atherosclerotic disease, six had diabetic nephropathy and four were smokers. The arterio-venous access, which led to the “steal” syndrome, was proximally located in all (antecubital in 8, thigh area in 1). “Steal” symptoms included hand pain, paraesthesia, neurologic deficits and gangrenous ulcers. DRIL was technically successful in all patients. There were no perioperative deaths. Immediate and complete relief of pain was achieved in eight of the nine patients. One patient with gangrene later required a transmetacarpal amputation. No patient required hand amputation. During follow-up (range 1–26 months) hemodialysis was continued uninterruptedly using the problematic AVA[2] in all patients. Thrombosis occurred in the AVA in only two patients after the DRIL procedure at 9 and 24 months postoperatively, respectively. Three patient deaths were unrelated to the DRIL.

Conclusions: In selected patients the DRIL procedure is a safe and effective way to treat the “steal” syndrome. AVA patency is not compromised by this operation. Preoperative angiography, before and after manual compression of the AVA, is crucial for the proper selection of patients who will benefit most from the DRIL procedure.