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Arthur R H van Zanten

Publications and source records attributed to Arthur R H van Zanten.

10 recordsLinked to original sources
PubMed2006

Reliable new high-performance liquid chromatographic method for the determination of ciprofloxacin in human serum.

Ciprofloxacin is a broad-spectrum antibacterial drug, being used in a wide range of infections. A method to quantify the total (unbound + protein-bound) ciprofloxacin concentrations in human serum is presented based on rapid liquid-liquid extraction, followed by reversed-phase liquid chromatography and UV detection at 280 nm. The calibration range used was 2 to 10 mg/L. The mean accuracy and precision (CV%) were all within specifications: at 0.2 mg/L 81.2% (10.1%), assigned to be the lower limit of quantification (LLOQ), at 8 mg/L 103.6% (4.48%), at 14 mg/L 103.1% (3.98%). Metabolites and frequently used comedications showed minimal interference. Sample storage conditions suitable for routine determination of serum ciprofloxacin concentrations for daily therapeutic drug monitoring (gel-collection tubes and PVC tubes at 4 degrees C) and for intermittent batch-wise analyses for research purposes (PVC tubes at -18 degrees C) showed acceptable sample stability after storage for 48 hours (4 degrees C) and 6 months (-18 degrees C).

Animals↗
PubMed2005

Hospital-acquired sinusitis is a common cause of fever of unknown origin in orotracheally intubated critically ill patients.

INTRODUCTION: Sinusitis is a well recognised but insufficiently understood complication of critical illness. It has been linked to nasotracheal intubation, but its occurrence after orotracheal intubation is less clear. We studied the incidence of sinusitis in patients with fever of unknown origin (FUO) in our intensive care unit with the aim of establishing a protocol that would be applicable in everyday clinical practice. METHODS: Sinus X-rays (SXRs) were performed in all patients with fever for which an initial screening (physical examination, microbiological cultures and chest X-ray) revealed no obvious cause. All patients were followed with a predefined protocol, including antral drainage in all patients with abnormal or equivocal results on their SXR. RESULTS: Initial screening revealed probable causes of fever in 153 of 351 patients (43.6%). SXRs were taken in the other 198 patients (56.4%); 129 had obvious or equivocal abnormalities. Sinus drainage revealed purulent material and positive cultures (predominantly Pseudomonas and Klebsiella species) in 84 patients. Final diagnosis for the cause of fever in all 351 patients based on X-ray results, microbiological cultures, and clinical response to sinus drainage indicated sinusitis as the sole cause of fever in 57 (16.2%) and as contributing factor in 48 (13.8%) patients with FUO. This will underestimate the actual incidence because SXR and drainage were not performed in all patients. CONCLUSION: Physicians treating critically ill patients should be aware of the high risk of sinusitis and take appropriate preventive measures, including the removal of nasogastric tubes in patients requiring long-term mechanical ventilation. Routine investigation of FUO should include computed tomography scan, SXR or sinus ultrasonography, and drainage should be performed if any abnormalities are found.

Clinical Protocols↗
PubMed2003

Importance of nondrug costs of intravenous antibiotic therapy.

INTRODUCTION: Costs are one of the factors determining physicians' choice of medication to treat patients in specific situations. However, usually only the drug acquisition costs are taken into account, whereas other factors such as the use of disposable materials, the drug preparation time and the staff workload are insufficiently taken into consideration. We therefore decided to assess true overall costs of intravenous (IV) antibiotic administration by performing an activity-based costing approach. METHODS: A prospective survey on costs and workload by means of a time and motion analysis and activity-based costing was performed in a 605-bed secondary referral centre with 20 intensive care unit beds. The subjects were 50 consecutive patients admitted to our hospital with community-acquired pneumonia or intra-abdominal infections requiring treatment with IV antibiotics. A time and motion analysis of 103 routine acts of preparing and administering IV antibiotics was performed in the intensive care unit and in the Department of Internal Medicine. To measure the entire process an inventory and work flowchart were made using detailed questionnaires completed by members of the nursing staff, the medical staff and the pharmacy staff. In addition, questionnaires were distributed to management and secretarial staff to determine additional overhead costs. The average costs for different methods of IV antibiotic administration were then compared by timing all steps in the process. Four different methods of drug administration were used: administration by volumetric pump, administration by syringe pump, administration by 'unaided' infusion bag, and administration by direct IV injection. RESULTS: The average times required for each of these procedures, including preparation and administration of the drug, were 4:49 +/- 2:37, 4:56 +/- 2:03, 5:51 +/- 3:33 and 9:21 +/- 2:16 min (mean minutes:seconds +/- standard deviation), respectively. When the costs for expended staff time and materials (not including drug costs) were calculated this resulted in average costs of 5.65, 7.28, 5.36 and 3.83, respectively, for administration of each dose of antibiotics. These costs represent between 11% and 53% of the total daily costs of antibiotic therapy. Compared with the acquisition costs, these indirect costs ranged from 13% to 113%. Not included in this comparison is the time required for insertion of an IV catheter, which was found to be 10:15 +/- 6:31 min with an average calculated cost of 9.17. CONCLUSIONS: Total costs of IV antibiotic administration are formed not only by the costs of the drugs themselves, but also, to a substantial degree, by the time expended by medical and nursing staff, costs of disposable materials and overhead costs. Physicians making decisions regarding the use of specific medications in intensive care unit patients should take these factors into account. Use of IV antibiotics is associated with considerable workload and additional costs that can exceed the acquisition costs of the medications themselves.

Adult↗