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I C Gyssens

Publications and source records attributed to I C Gyssens.

At least 19 recordsLinked to original sources
PubMed2006

[A patient with long-term, unrecognized leishmaniasis].

A man from Surinam presented at the Department of Internal Medicine with a perforated septum and progressive collapse of the nose. This condition had existed for 22 years, though earlier analysis had not revealed the cause. Microscopic analysis showed a granulomatous inflammatory reaction, with cultures revealing of Leishmania. The diagnosis was mucocutaneous leishmaniasis and PCR indicated Leishmania braziliensis complex. The patient was treated for mucocutaneous leishmaniasis by a 28-day course of intravenous sodium-stibogluconate therapy. Initially, treatment was stopped briefly due to neurotoxicity, but was recommenced and successfully completed. After treatment the infection parameters returned to normal and the patient was referred for reconstructive nasal surgery. Due to a low parasitic load mucocutaneous leishmaniasis can be difficult to detect, especially in chronic cases. However, the use of molecular techniques has improved both the sensitivity and specificity of detection. The ability to distinguish between different species and sub-species is of prognostic and therapeutic relevance.

Animals↗
PubMed2006

[Optimalisation of the antibiotic policy in The Netherlands. XI. The national electronic antibiotic guide'SWAB-ID' for use in hospitals].

The 'Stichting Werkgroep Antibioticabeleid' (Dutch Working Party on Antibiotic Policy) has developed an electronic national antibiotic guide for the antibiotic treatment and prophylaxis of common infectious diseases in hospitals. This guide also contains information on the most important characteristics of antimicrobial drugs. Advice on antibiotic treatment is based on existing national evidence-based guidelines, where available. Where no guideline is available, the advice is based on an inventory of the antibiotic policies of the 12 Dutch centres with an infectious disease or medical microbiology training programme. The national antibiotic guide can be accessed through the SWAB website (www.swab.nl) and can also be downloaded on PDA/PocketPC, free of charge. Every hospital antibiotic formulary committee in the Netherlands will be offered the opportunity to edit The national version for local use.

Anti-Bacterial Agents↗
PubMed2005

National guidelines for the use of antibiotics in hospitalised adult patients: the SWAB guidelines revisited.

Since 1996, the Dutch Working Party on Antibiotic Policy (Stichting Werkgroep AntibioticaBeleid, SWAB) has been developing national guidelines for the use of antibiotics in hospitalised adult patients. As a result of both an inventory of the wishes of the users of these guidelines and the recently developed criteria for evidence-based guideline development, we have revised our format for the development of SWAB guidelines. By involving the members of the relevant professional societies and giving them the opportunity to comment on the guidelines at an early stage, we are aiming for a successful implementation of the guidelines in the hospitals.

Adult↗
PubMed2005

International guidelines for infectious diseases: a practical guide.

A growing number of organisations have become involved in the development of guidelines for infectious diseases (ID). The degree of acceptation of guidelines varies from one country to another. Some of these national differences are determining the practices of prescribing antibiotics, and infection control both in hospitals and in the community. This review provides updated information on ID guideline programmes, in particular on the topic of antimicrobial therapy. It is aimed at clinicians, both in their role as care providers and as designers of local antibiotic guidelines (antibiotic booklets). Definitions are given and the process of development is discussed. International and national ID guideline programmes in the English language are presented. Many URLs provide access to the different websites where most guidelines can be downloaded free of charge.

Anti-Bacterial Agents↗
PubMed2004

Perioperative pharmacokinetics of cefotaxime in serum and bile during continuous and intermittent infusion in liver transplant patients.

BACKGROUND: Drug pharmacokinetics may be altered during liver transplantation. Cefotaxime (CTX), used as perioperative prophylaxis, demonstrates time-dependent killing and therefore continuous infusion might have pharmacodynamic advantages. OBJECTIVES: To determine the pharmacokinetics of CTX and desacetylcefotaxime (DCTX) in serum, bile and urine during continuous and intermittent infusion when performing liver transplantation. METHODS: Fifteen patients undergoing liver transplantation were studied after continuous infusion (CI) (4000 mg iv per 24 h following a loading dose of 1000 mg) and intermittent bolus infusion (BI) (1000 mg iv four times daily). Samples were collected during the first 48 h after liver transplantation. Concentrations of CTX and DCTX were determined by HPLC. RESULTS: During surgery, the mean concentration in serum after CI was 18 mg/L. The lowest serum concentration was 5 mg/L in the CI group and levels were undetectable in the BI group. Target serum concentrations of > or =4 mg/L were reached for 100% of the dosing interval during CI and approximately 60% during BI. Post-operatively, the mean concentration in serum after CI was 26 mg/L. The lowest serum concentration was 8 mg/L in the CI group and levels were undetectable after BI. The peroperative pharmacokinetics of CTX in this patient group were deranged and variable, mainly caused by an increased volume of distribution and decreased hepatic clearance. Metabolism was hampered, but DCTX area under the curve (AUC)/CTX AUC ratios varying between 0.7-0.9 were reached peroperatively. Post-operatively, DCTX AUC/CTX AUC ratios were higher (1.1-1.4). Unchanged CTX in bile was approximately 0.1% of the administered dose, leading to concentrations >4 mg/L throughout the dosing interval for both regimens. CONCLUSION: Although an intermittent bolus infusion of CTX 1000 mg produces t > target concentration for 60% of the dosing interval during liver transplantation, serum concentrations may be insufficient during the reperfusion phase. Continuous infusion overcomes this. Post-operatively, CTX clearance is impaired by decreased metabolic clearance and there is substantial accumulation of DCTX. In bile, sufficient concentrations of CTX and its active metabolite are reached with both regimens.

Adult↗
PubMed2003

Adherence to local hospital guidelines for surgical antimicrobial prophylaxis: a multicentre audit in Dutch hospitals.

OBJECTIVE: To study the adherence to local hospital guidelines for antimicrobial prophylaxis in surgery, and explore reasons for non-adherence. METHODS: A prospective, multicentre audit of elective procedures, without prior suspicion of infection, was carried out in 13 Dutch hospitals. By reviewing medical, anaesthetic and nursing records, and medication charts, the prescription of antibiotics was compared with the local hospital guideline on antibiotic choice, duration of prophylaxis, dose, dosing interval and timing of the first dose. RESULTS: Between January 2000 and January 2001, 1763 procedures were studied. Antibiotic choice, duration, dose, dosing interval and timing of the first dose were concordant with the hospital guideline in 92%, 82%, 89%, 43% and 50%, respectively. Overall adherence to all aspects of the guideline, however, was achieved in only 28%. The most important barriers to local guideline adherence were lack of awareness due to ineffective distribution of the most recent version of the guidelines, lack of agreement by surgeons with the local hospital guidelines, and environmental factors, such as organizational constraints in the surgical suite and in the ward. CONCLUSION: This study shows that, although adherence to separate aspects of local hospital guidelines for surgical prophylaxis in the Netherlands is favourable, overall adherence to all parameters is hard to achieve. Adherence to guidelines on dosing interval and timing needs improvement, in particular. To increase the quality of antimicrobial prophylaxis in surgery, effort should be put into developing guidelines acceptable to surgeons, in adequately distributing the guidelines and to facilitating logistics. Audits of surgical prophylaxis may help hospitals identify barriers to guideline adherence.

Adult↗
PubMed2003

Comparative evaluation of three chromogenic agars for detection and rapid identification of aerobic Gram-negative bacteria in the normal intestinal microflora.

OBJECTIVE: To compare three different chromogenic agars and MacConkey agar for the detection of aerobic Gram-negative bacteria in the normal intestinal microflora and to assess the accuracy of the chromogenic agars for the direct identification of Escherichia coli. METHODS: A total of 164 Gram-negative clinical isolates (E. coli, Proteus, Klebsiella, Enterobacter, Morganella and Pseudomonas species) and 30 stool specimens were inoculated in parallel on four media: Chromagar E. coli/Coliform, Chromogenic urinary tract infection UTI medium, CHROMagar Orientation and MacConkey agar. All colonies that differed by color and/or morphology were selected for further identification by VITEK 1 and/or API 20E from each medium. RESULTS: On E. coli/Coliform agar five out of 32 (16%) E. coli strains failed to produce the color as described by the manufacturer. No remarkable discrepancies were found for the other clinical isolates. There was no significant difference in detection rate (DR) of aerobic Gram-negative bacteria in stool specimens between the different chromogenic agars and MacConkey agar. The overall DR was about 84%, and varied from 100% for monomicrobial specimens to 33% for polymicrobial specimens. The positive predictive values (PPV) for the direct identification of E. coli on Chromagar E. coli/Coliform, Chromogenic UTI medium and CHROMagar Orientation were 1.00, 0.93 and 0.93, respectively. The negative predictive values (NPV) were 0.53, 0.68 and 0.69, respectively. CONCLUSION: Chromogenic UTI medium and CHROMagar Orientation are the preferred media because of the higher NPV. The high PPV of these agars allows accurate and rapid identification of E. coli.

Agar↗
PubMed2002

[Treatment adherence amongst HIV-infected patients in Rotterdam: poorer prognosis independent of nationality in heterosexual infected patients, intravenous drug users, Negroid and Latin-American patients].

OBJECTIVE: To assess adherence to antiretroviral therapy (ART) in Dutch and non-Dutch HIV-infected patients. DESIGN: Observational, cross-sectional study. METHODS: Consecutive HIV-infected patients taking ART and visiting the internal medicine outpatients' clinic at the Rotterdam Dijkzigt University Hospital between 1 February until 30 April 2001 were interviewed by a multilingual interviewer using a standard questionnaire. Classification of adherence was based on the interview data. Multivariate analysis was used to determine independent predictors of adherence. Nationality was defined as 'Dutch' if the person was born in the Netherlands, and otherwise as 'non-Dutch'. RESULTS: The 203 patients included in this study comprised 131 men and 69 women with an average age of 42 years. There were no data available on treatment adherence for 3 of the patients. Of the 81 Dutch patients, 60 (74%) adhered to the treatment compared with 68 (57%) of the 119 non-Dutch patients. However, after correction for sex, risk group, race and duration of treatment, there was no difference in treatment adherence between these two groups (OR: 0.6; 95% CI: 0.2-1.9). Failure to adhere to treatment was seen most frequently in the 109 heterosexually infected patients (OR: 2.6; 0.98-6.7), the 22 intravenous drug users (OR: 3.3; 1.04-10.1), as well as in the group of Negroid patients (OR: 3.5; 1.1-11.3) and Latin-American patients (OR: 8.5; 1.7-42.7).

Adult↗
PubMed2002

Experience with a once-daily dosing program of aminoglycosides in critically ill patients.

BACKGROUND: As aminoglycosides show concentration-dependent killing, once-daily aminoglycoside (ODA) regimens have been instituted. Data on experience with ODA regimens in critically ill patients are limited. OBJECTIVES: 1) To evaluate the ODA-program in critically ill patients; 2) to describe the pharmacokinetics of aminoglycosides (gentamicin and tobramycin); and 3) to assess the incidence of nephrotoxicity associated with an ODA regimen in this specific of group patients. DESIGN: A prospective, descriptive study. SETTING: Eighteen-bed surgical and 12-bed medical intensive care unit in a referral centre. PATIENTS: Eighty-nine critically ill patients with a suspected or confirmed infection for which gentamicin or tobramycin was indicated and a creatinine clearance > 30 ml/min were monitored. One hundred and nine pharmacokinetic profiles were gathered. INTERVENTIONS: A first dose of 7 mg/kg/24 h of gentamicin or tobramycin was given to every patient independent of renal function. Subsequent doses were chosen on the basis of the pharmacokinetic results of the first dose. MEASUREMENTS: Serum samples were collected 1 h and 6 h after start of the aminoglycoside infusion. All samples were assayed by using immunofluorescence. Pharmacokinetic parameters were estimated using a one-compartment model. RESULTS: The volume of distribution of aminoglycosides was significantly higher in critical ill patients with septic shock than in those without. Consequently, the maximum concentration reached was significantly lower in patients with septic shock. In P. aeruginosa infections the mean (SD) estimated Cmax/MIC ratio was 10.3 (3.3). In n = 17 (49%) of the patients treated > 24 h ( n = 35), a dose adjustment or lengthening of interval was necessary. The recommended dosing interval based on the Hartford Hospital nomogram and one-serum concentration at 6 h was correct in only 62% of all cases. Signs of renal impairment occurred in n = 12 (14%) of the patients; in all survivors renal function recovered completely and no haemofiltration was needed. CONCLUSIONS: An ODA-regimen of 7 mg/kg produced Cmax/MIC ratios > 10 in the majority of critically ill patients in our population. Septic shock and renal dysfunction caused an aberrant pharmacokinetic profile of aminoglycosides in these patients. Therefore, individual therapeutic drug monitoring is warranted. Signs of renal impairment were common in the presence of shock, but appeared to be reversible.

Adult↗
PubMed2002

Pharmacokinetics of ceftazidime in serum and peritoneal exudate during continuous versus intermittent administration to patients with severe intra-abdominal infections.

Ceftazidime demonstrates time-dependent killing, which is maximal at 4 x or 5 x MIC for the organism, consequently continuous infusion (CI) has been proposed to ensure adequate ceftazidime concentrations for the entire course of therapy. Severe intra-abdominal infections (IAIs) require surgical or percutaneous drainage for management, and ceftazidime is frequently prescribed. Cardiovascular or metabolic changes and renal or liver dysfunction may alter drug pharmacokinetics during severe IAIs, and no data exist on concentrations of ceftazidime reached in the peritoneal fluid. The objectives here were to determine the pharmacokinetics of ceftazidime during continuous and intermittent administration in patients with severe IAIs, and to measure the concentrations of ceftazidime in the peritoneal exudate. Eighteen surgical patients with severe IAI and a creatinine clearance of >30 mL/min were studied. A non-randomized pilot study of six patients treated with CI alone was followed by a prospective, randomized comparative study of 12 patients. Pilot study patients received ceftazidime 1 g iv followed by a 4.5 g CI over 24 h. Randomized patients received either ceftazidime continuously as above or 1.5 g tds. Samples for pharmacokinetic analyses were collected on days 2 and 4. Ceftazidime concentrations were determined by high-performance liquid chromatography. CI resulted in a mean serum concentration >40 mg/L and a T> 4 x MIC for most pathogens encountered in severe IAIs for >90% of the course of therapy in both serum and peritoneal exudate. Eight-hourly administration resulted in T> 4 x MIC for most pathogens encountered in severe IAIs for >90% of the dosing interval, but in peritoneal exudate for only 44% of the dosing interval. During CI, AUCs in the peritoneal exudate were c. 60% of the concomitant serum AUCs. In critically ill surgical patients with severe IAIs, CI of ceftazidime resulted in more favourable concentrations in serum and peritoneal exudate than 8-hourly bolus infusion.

Adult↗
PubMed2001

[Female patient with cutaneous anthrax in Belgium].

A 23-year-old Turkish woman was admitted with an infection of the left thumb. The clinical picture was typical for cutaneous anthrax. Microbiological tests confirmed the diagnosis 'infection by Bacillus anthracis'. She recovered when treated with penicillin, although later tests revealed that the bacteria were resistant to this antibiotic. The patient became infected in Belgium as a result of wounding herself on the teeth of an illegally slaughtered sheep, which had possibly become infected in the pasture. Recognising the characteristic clinical picture of cutaneous anthrax is essential for prompt treatment and a favourable prognosis.

Adult↗
PubMed2001

Indinavir crystallization around the loop of Henle: experimental evidence.

OBJECTIVE: To determine the probable site of the nephron and the plasma indinavir (IDV) concentration at which intrarenal IDV crystallization occurs. DESIGN: We performed in vitro crystallization experiments in IDV solutions simulating conditions found in the nephron. METHODS: To determine intrarenal IDV concentrations at which conditions in the nephron allow crystallization, several concentrations of IDV basic solutions (0-800 mM) were titrated from pH 4.0 to higher pH values until crystals formed within 1 minute. Based on the combination of pH and ionic strength at which crystals formed, we determined the site of the nephron at which this combination was first attained. Based on the capacity for concentration at that site, we were able to measure the corresponding plasma IDV concentration. RESULTS: Under conditions normally found at the proximal tubule (i.e., pH 6.7 and ionic strength of 200 mM), IDV crystallized at 200 mg/L. Under conditions applying to the loop of Henle, pH 7.4 and ionic strength of 200 mM, IDV crystallized at 125 mg/L, which would correspond to a plasma IDV concentration of 8 mg/L. CONCLUSIONS: IDV crystallization is most likely in the loop of Henle and may already start at plasma IDV concentrations as low as 8 mg/L. Increasing hydration does not reduce the risk of IDV crystallization in the loop of Henle but instead prevents IDV crystallization and aggregation in the lower urinary tract. It remains to be confirmed whether prevention of high IDV plasma concentrations will reduce the risk of IDV crystallization in the loop of Henle.

Crystallization↗
PubMed2001

Pharmacokinetics of sequential intravenous and enteral fluconazole in critically ill surgical patients with invasive mycoses and compromised gastro-intestinal function.

OBJECTIVES: (1) To determine the pharmacokinetics of sequential intravenous and enteral fluconazole in the serum of surgical intensive care unit (ICU) patients with deep mycoses. (2) To determine the concentrations of fluconazole reached at the site of infection. (3) To determine if enteral administration of fluconazole, which has an important pharmaco-economic advantage, is justified in this specific patient group. DESIGN: Descriptive, sequential study as a part of a therapeutic drug monitoring programme. SETTING: Eighteen-bed surgical ICU in a referral centre. PATIENTS: Fourteen critically ill surgical patients with recent gastro-intestinal (GI) surgery and deep mycosis caused by a fluconazole-susceptible fungus and a calculated creatinine clearance of more than 40 ml/min. INTERVENTIONS: Fluconazole dosage regimen: 400 mg i. v. every 24 h with an extra dose of 400 mg i.v. after 12 h on day 1. If the clinical condition allowed enteral administration on day 4, the content of two capsules of 200 mg was given via the feeding tube with concomitant enteral feeds. MEASUREMENTS AND MAIN RESULTS: Serum, exudate from the site of infection and urine samples collected at assumed steady state ( after > or = 5 doses). Fluconazole concentrations were determined by high-performance liquid chromatography (HPLC). The mean area under the concentration curve (AUC0-24 h) in serum after enteral administration did not significantly differ from the AUC0-24 h during intravenous treatment. The elimination half-life was longer compared to healthy volunteers. The mean (95% CI) estimated bioavailability was 124 (90-158)%. The mean (95% CI) area under the concentration time curves (AUCs) achieved in the exudate from the site of infection were 67 (55-79)% of the AUCs reached in serum for both regimens. CONCLUSIONS: In critically ill patients with recent GI surgery and/or peritonitis the bioavailability of enteral fluconazole was adequate. The concentrations of fluconazole reached in exudate were lower than those in serum for both regimens, but adequate to treat most cases of deep mycoses in this specific patient group.

Antifungal Agents↗
PubMed2001

Quality measures of antimicrobial drug use.

Antimicrobial use is the major determinant in the development of resistance. Many parameters of importance for optimal quality of antimicrobial therapy have already been defined. Maximal efficacy of the treatment should be combined with minimal toxicity at the lowest cost. Quality of antimicrobial drug use is dependent on knowledge of many aspects of infectious diseases. Considering efficacy, many of our indications for antimicrobial use need critical evaluation. Irrational use should be discouraged. Avoidance of the development of resistance is a quality parameter that will need increasing attention. This paper reviews the well-established factors that may influence the appropriateness of pharmacotherapy with antimicrobial drugs. It cites recent evidence supporting principles of prudent prescribing and gives an overview of audits that have addressed these parameters. Measures relating to resistance are discussed.

Anti-Bacterial Agents↗
PubMed2001

Quality of antimicrobial drug prescription in hospital.

There is worldwide concern about the development of antimicrobial resistance [1]. Selective pressure by antimicrobial drugs is by far the most important driving force for the development of resistance. Antimicrobial drugs are among the most commonly prescribed drugs in hospitals. In developed countries, some 30% of the hospitalized patients will be treated with these drugs. It is generally accepted that antimicrobial prescribing is often suboptimal, even in a country like the Netherlands, where both antibiotic consumption and microbial resistance rates are low [2,3]. The major problem with inappropriate prescribing is because of insufficient education in infectious diseases and antimicrobial therapy. Often, the prescription of these drugs with little toxicity is unjustified because of insecurity about the diagnosis of the clinician; 'drugs of fear' [4]. In our surveys, some 15% of the antibiotic prescriptions in surgical and internal medicine wards were considered unjustified [5,6]. Many prescribers are not yet fully aware that their justified or unjustified prescription adds to the resistance problem. In this paper, aspects of the quality of antimicrobial prescribing in the hospital setting will be discussed.

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