Optimal Tobramycin Dosage in Patients with Cystic Fibrosis – Evidence for Predictability Based on Previous Drug Monitoring

Summary A retrospective analysis of files of patients with cystic fibrosis and pulmonary exacerbations was performed to investigate whether an individual dosage of tobramycin once established by serum level determination allows a reliable prediction of the adequate dosage in a consecutive exacerbation. All patients hospitalized ≥ 2 times between May 1997 and September 1998 with pulmonary exacerbation due to Pseudomonas aeruginosa infection susceptible to tobramycin were included. The initial dosage to tobramycin was 5 mg/kg body weight every 12 h followed by drug level determinations to establish the optimal dose. In a consecutive exacerbation the same dosage per kg body weight was used again and drug level determinations were repeated. Sixteen patients (six female = 38%) with a mean age of 24 years (median: 26) years, range: 9–,33) were hospitalized for 49 pulmonary exacerbations (2–6 per patient, mean: 3, median: 2.5). During the first episode of tobramycin treatment in the study period all trough levels were < 2 μg/ml (median: 0.6) and the peak levels were 7.1–16.9 μg/ml (median: 11.9). In four patients the peak level was > 12 μg/ml. In 28 consecutive episodes the dosage of tobramycin was chosen based on optimal results of previous drug level monitoring and in 27 instances (96%) the previously established optimal dose was confirmed. In five consecutive episodes the tobramycin dosage had been increased erroneously and this resulted in abnormally high peak levels in three cases. These findings suggest that a safe and therapeutic tobramycin dosage in an individual patient with cystic fibrosis is predictable based on a previously established optimal dosage. Received: December 22, 1998 · Revision accepted: April 18, 1999     

Myocardial preservation using Celsior solution in cardiac transplantation: early results and 5-year follow-up of a multicenter prospective study of 70 cardiac transplantations

BACKGROUND: Several storage methods using a wide variety of extracellular or intracellular solutions applied either as continuous perfusion, intermittent perfusion, or simple immersion of the heart have been commonly used. We have performed a prospective randomized multicenter study of 70 cardiac transplantation recipients to evaluate the Celsior solution for cardiac preservation. METHODS: Seventy consecutive patients were included in this trial and received a cardiac graft arrested and preserved with Celsior. The first follow-up period was 1 month. The mean age of the recipients was 49 years (range, 28 to 66 years), and 81.7% were male. The main disease was nonobstructive cardiomyopathy (64.3%). The age range of donors was between 14 and 56 years with a mean of 33 years. The majority of grafts (73%) were stored in 1 L of Celsior. A midterm follow-up at 5 years was performed and was 100% complete. RESULTS: The operative mortality (<30-day) rate was 6 of 70 (8.6%). Sixty-three patients (90%) had at least satisfactory hemodynamic measurements on day 2. The first postoperative echocardiograms showed good myocardial performance for 90% of the grafts. Actuarial survival rate at 5 years was 75% +/- 5.1%. CONCLUSIONS: The use of Celsior in cardiac transplantation was safe and very effective. This solution proved very valuable in at-risk patients.     

Health risks of electromagnetic fields. Part III: Risk analysis

The management of potential health risks from electromagnetic (EM) fields presents both scientific and nonscientific challenges. When the scientific evidence is ambiguous, as is the case with EM fields, expert judgment of this evidence becomes particularly important. This article provides biomedical researchers with a comprehensive assessment of the status of EM health risk based on our two previous articles [Parts I and II, Critical Reviews in Biomedical Engineering, Volume 31, Issue 3]. Ambiguous evidence also necessitates rigorous public debate. This article also discusses effective risk communication approaches that play a key role in the EM risk issue. Because of uncertainty about health risks associated with EMF exposure, the public is more likely to experience difficulty in evaluating the available information and rely more on perceptions than facts when drawing conclusions. Even the most effective risk communication approaches are not likely to clarify all of the subtleties surrounding EM fields as a population health issue. Thus it is essential that all stakeholders involved in this issue participate in developing consensus solutions.     

Health risks of electromagnetic fields. Part II: Evaluation and assessment of radio frequency radiation

The increasing use of different radio frequency (RF)-emitting devices in residential and occupational settings has raised concerns about possible health effects of RF energy emitted by such devices. The debate about the potential risks associated with RF fields will persist with the prevalent network-connected wireless products and services targeting the marketplace for all kinds of consumer use. The aim of this article is to provide biomedical researchers with a review and critical evaluation of the current literature on acute and long-term health risks associated with RF radiation (RFR). Issues examined include safety standards for RFR; dosimetry and measurement surveys; and toxicological, epidemiological, and clinical studies of health outcomes that may be associated with RFR. Overall, the existing evidence for a causal relationship between RFR and adverse health effects is limited. Additional research is needed to clarify possible associations between RFR and biological effects noted in some studies. Particular attention should be directed toward long-term, low-level exposure to RFR.     

Comparison of the immunogenicity and reactogenicity of two commercially available hexavalent vaccines administered as a primary vaccination course at 2, 4 and 6 months of age

Infants (N = 459) were randomly assigned to receive either Infanrix hexa or Hexavac vaccines at 2, 4 and 6 months of age as a primary vaccination schedule. The immunogenicity of the hepatitis B component was statistically significantly higher for Infanrix hexa compared to Hexavac in terms of both seroprotection (98.6% versus 94.7%, p = 0.0302) and GMCs (905.6 versus 226.4, p < 0.0001). Significantly (p < or =0.0001) higher antibody levels against diphtheria and the 3 polio components were also induced by Infanrix hexa. The responses to tetanus, Hib and pertussis components were similar. The incidences of clinically relevant solicited symptoms, unsolicited symptoms or serious adverse events were low in both groups.