Myocardial laser revascularization in the year 2000 as seen by a Norwegian specialist panel. The process of evaluating and implementing new methods in clinical practice.

OBJECTIVE: In Norway "Transmyocardial laser revascularization" as a routine method was prohibited by the Ministry of Health in 1995 due to lacking evidence of treatment effect and concerns about procedural morbidity and mortality. In 1999 Norwegian health authorities asked for a re-evaluation of the method based on a systematic review of literature. METHODS: Medline and Embase were searched and a total of 267 articles were identified. Publications were classified by an expert panel according to type of study and importance for the project. RESULTS: Based on the literature review the panel concluded that heart laser treatment does not have a life-saving effect, nor does it improve myocardial function. However, the method has a considerable short-term symptomatic effect, the mechanism of which is not understood. Neoangiogenesis, denervation and placebo may play a role. Based on the report the Norwegian health authorities recommended use of this method be restricted to scientific trials only. CONCLUSIONS: Based on a systematic literature review it was concluded that the only documented effect of heart laser treatment is symptom relief, the mechanism for which is unclear. It could partly or totally be a placebo effect. A conflict of interest may arise when new technologies are to be implemented in health care. The communication between professionals evaluating scientific results and decision makers is challenging. Quality assurance of this process may be obtained by use of expert panels working under the auspices of an official institution.

[Telemedicine and medical technology assessment]. / Telemedisin og medisinsk metodevurdering.

Telemedicine is a rapidly evolving technology. Health technology assessments of telemedicine applications are needed to assist decision-makers. A few health technology assessment reports and a Cochrane protocol on principles for evaluating telemedicine installations have been published. Studies providing evidence on the effectiveness of teleconsultations and teleradiology are summarised. Telemedicine shows great promise in some areas; however, the use of this technology should still be regarded as experimental. Therefore, it should be implemented in a way that facilitates ongoing evaluation.

[Principles for assessment and diagnosis of work-related pulmonary and pleural diseases]. / Prinsipper for utredning og diagnostikk ved yrkesrelaterte lunge- og pleurasykdommer.

Proposals for diagnostic methods and clinical evaluation of occupational lung and pleural diseases have been worked out by a Working Group appointed by the Norwegian Thoracic Society and the Norwegian Society of Occupational Medicine. The management of this group of diseases demands both an evaluation of occupational exposure and a specific pulmonary diagnosis. Recommendations were made especially for obstructive, interstitial, and malignant diseases.

[Expert statement and assessment of medical impairment in work-related pulmonary disease]. / Spesialisterklaeringen og fastsettelse av medisinsk invaliditet ved yrkesrelaterte lungesykdommer.

The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working group to standardise diagnostic procedures and evaluation of work-related respiratory disorders. In cases of suspected work-related diseases the physician may be asked by the National Insurance Administration or an insurance company to make a statement which will be one of the documents used to decide the patient's right to compensation benefit. We discuss the role of the physician as an independent expert. This is different from his role as clinician. The statement should include a balanced presentation of information from different sources, including health and occupational history, and the employer's information about the work environment (quantitative and qualitative exposure data). The statement must also include the results of a clinical examination and an assessment of functional status based on objective tests. The paper contains recommendations for evaluation of permanent impairment in light of the present Norwegian laws and regulations.

The effect on pulmonary function of tangential field technique in radiotherapy for carcinoma of the breast.

Twenty-five patients treated by lumpectomy and radiotherapy for Stage I breast cancer were enrolled in a prospective study to measure the effects of tangential field irradiation on pulmonary function. Fractional doses of 2 Gy to a total of 50 Gy were administered with the tangential technique. An additional 10 Gy (2 Gy x 5) was given as direct booster. Dynamic and static lung volumes, distribution of ventilation and gas transfer were measured before irradiation and at varying intervals up to 1 year after the completion of therapy. There was a small, but statistically significant decrease in the forced vital capacity (mean 63 ml) and the forced expiratory volume in 1 second (mean 79 ml) measured 3 months after irradiation (p less than 0.05). These changes were reversed within 1 year. The reduction in total lung capacity (mean 240 ml) after 3 months was nearly significant (p = 0.06). The remaining variables did not change to a significant degree. We conclude that a slight restrictive ventilatory impairment may occur when a combined tangential and direct booster technique is applied. The changes are, however, small and reversible, and imply no clinical importance.

[Magnetic tomography in lung cancer]. / Magnettomografi ved lungekreft.

Reasonable long-term survival in bronchogenic carcinoma can be expected only if complete resection is performed. Accurate preoperative staging is essential, and computed tomography is not always sufficient as staging investigation. We discuss the indications for magnetic resonance imaging in these patients, and describe the use of this method in three patients. Magnetic resonance imaging should be used as a supplement to computed tomography in selected patients.

The influence of sustained release theophylline therapy on free fatty acids in serum.

The serum concentrations of theophylline, total free fatty acids (FFA) and subgroups were studied in ten healthy volunteers treated with sustained release theophylline twice daily during 9 days. Analyses were performed before and on day 1, 4 and 9 of treatment. Mean theophylline serum levels within the therapeutic range were obtained during the study, ranging from 62 +/- 7 to 82 +/- 10 mumol/l. The mean serum concentrations of total FFA and subgroups increased significantly during treatment, showing the highest levels on day 4. Comparing fasting total FFA concentrations, an increase of 123% and 48% from pretreatment levels were found on day 4 and 9, respectively. The subgroups were influenced to a different degree by theophylline intake. Arachidonic acid (20:4) was not increased, while among the others, saturated FFA increased less than the unsaturated.

Long-term therapy with sustained-release theophylline.

Twenty patients with partially reversible bronchial obstruction due to chronic obstructive lung disease participated in a study comparing serum levels, clinical and side-effects of a sustained-release formulation of theophylline with placebo. Prior to the study, theophylline dosages were individually adjusted to give serum levels of 55 to 75 mumol/l 4 hours after tablet intake. Theophylline or placebo was then administered every 12 hours with crossover after 6 weeks. During the study, patients were examined in the morning every second week and lung function tests carried out before and after salbutamol inhalation. Doses required to achieve the desired serum concentration showed great inter-individual variations, but the obtained levels were stable during the whole study. Lung function tests were significantly better in the theophylline period. After inhalation of salbutamol, values were also better in the theophylline period but the differences were less marked and of no statistical significance. Subjective improvement from theophylline was not observed. Side-effects reported were mild and caused no withdrawals.

Pharmacokinetics and tissue penetration of ceftazidime: studies on lymph, aqueous humour, skin blister, cerebrospinal and pleural fluid.

The elimination kinetics and penetration of ceftazidime into skin blister and lymphatic fluid were studied in nine healthy volunteers following a 1 g iv bolus injection. From the concentration time curve in plasma the following pharmacokinetic parameters (mean +/- S.D.) were calculated: elimination half-life 1.85 +/- 0.33 h; area under the curves 127 +/- 12 mg . h/l; apparent volume of distribution: 21.1 +/- 2.61; total plasma clearance: 133 +/- 13 ml/min and renal clearance: 109 +/- 7 ml/min. Urine recovery after 8 h was 82% of the administered dose. Nearly the same elimination rate constant, half-life and area under the curve were demonstrated for blister fluid and lymph. The penetration of ceftazidime into cerebrospinal fluid (n = 19), aqueous humour (n = 21) and pleural effusions (n = 5) were studied in patients after a 2 g iv bolus injection. In patients with normal meninges (n = 14) the penetration was poor: the concentrations were less than 1 mg/l. In patients with meningitis (n = 5) levels of 18, 17, 16, 1 and 0.8 mg/l were found. Aqueous humour penetration was satisfactory, and a mean concentration of 11 +/- 4 mg/l corresponding to a penetration ratio of 19% was found. The penetration of ceftazidime into large pleural effusions was also good with concentrations from 17 +/- 3 to 28 +/- 2 mg/l, corresponding to a mean penetration ratio of 38%.

The influence of antacid on the absorption of two different sustained-release formulations of theophylline.

Twelve healthy volunteers were treated with two different sustained-release formulations of theophylline (Nuelin Depot 350 mg and Theo-Dur 300 mg) twice daily in an open cross-over study. The serum levels in steady state without and with concomitant administration of antacid were studied. Antacid did not influence the serum theophylline levels in the Theo-Dur treatment period, while in the Nuelin Depot treatment period antacids caused a significantly larger increase in serum levels of theophylline after drug intake. The difference between morning and peak concentrations were also much higher with the combination Nuelin Depot/antacid. This implies that physicochemical factors such as gastrointestinal fluid pH might influence the degradation and/or absorption of some slow-release theophylline formulations as reflected in serum concentrations, and thereby contribute to the therapeutic and side effects of such drugs.