Biomedical subjects

Christian S van der Hilst

Publications and source records attributed to Christian S van der Hilst.

3 recordsLinked to original sources

PubMed2006

Safe and unsafe duration of fasting for children with MCAD deficiency.

OBJECTIVE: To study the safe and unsafe duration of fasting in children with medium chain acyl-Coenzyme A dehydrogenase (MCAD) deficiency, the literature and the database on Dutch MCAD-deficient patients were searched for data on fasting studies in patients with MCAD deficiency. MATERIALS AND METHODS: These data were extended with information on fasting studies performed on our patients with MCAD deficiency known in the Beatrix Children's Hospital, UMC Groningen, The Netherlands. The data reflect considerable inter-individual variation and overlap between safe and unsafe duration of fasting. RESULTS: In six out of 35 fasting tests, symptoms were reported before hypoglycaemia was observed. Until 1 year of age, the median safe and unsafe duration of fasting was 12 hours (n=7, range 8-19 hours) and 18 hours (n=5, range 15-20 hours), respectively. After the first year of life, the median safe and unsafe duration of fasting was 18 hours (n=17, range 10-24 hours) and 20 hours (n=9, range 13-32 hours), respectively. CONCLUSION: Therefore, to conclude, we recommend a maximum duration of fasting in children with MCAD deficiency of 8 hours between 6 months and 1 year of age, 10 hours in the second year of life and 12 hours thereafter. From this study, no conclusions can be drawn on the duration of fasting during situations of intercurrent illness, especially with fever.

Acyl-CoA Dehydrogenase↗

PubMed2006

Surgical injuries of postmortem donor livers: incidence and impact on outcome after adult liver transplantation.

The exact frequency and clinical consequences of surgical hepatic injuries during organ procurement are unknown. We analyzed the incidence, risk factors, and clinical outcome of surgical injuries in 241 adult liver grafts. Hepatic injuries were categorized as parenchymal, vascular, or biliary. Outcome variables were bleeding complications, hepatic artery thrombosis (HAT), and graft survival. In 82 livers (34%), 96 injuries were detected. Most injuries were minor, but clinically relevant injuries were detected in 6.6% (16/241) of the livers. Fifty (21%) liver grafts had some degree of parenchymal or capsular injury, 40 (17%) had vascular injury, and 6 (2%) had an injury to the bile duct. Procurement region was the only risk factor significantly associated with surgical injury. The rate of hepatic artery injury was significantly higher in livers with aberrant arterial anatomy. Bleeding complications were found in 18% of patients who received livers with a parenchymal or capsular injury in contrast to 9% without parenchymal injury (P = 0.065). HAT was found in 23% of the patients who received a liver with arterial injury compared to 4% without arterial injury (P = 0.001). Overall graft survival rates were not significantly different for grafts with or without anatomical injury. In conclusion, surgical injuries of donor livers are an underestimated problem in liver transplantation and can be observed in about one-third of all cases. Clinically relevant injuries are detected in 6.6% of all liver grafts. Arterial injuries are associated with an increased risk of HAT.

Adult↗

PubMed2006

Noninferiority testing in cost-minimization studies: Practical issues concerning power analysis.

OBJECTIVES: In cost-minimization studies, it is important to establish noninferiority in the clinical effect of the treatments under investigation. The relationship between the proportion of patients reaching the end point in a study, equivalence limit (delta), and power is investigated in the context of cost-minimization studies with dichotomous clinical end points. Two formulations of the null-hypothesis, absolute and relative formulations of delta, will be explored. METHODS: Sensitivity analysis was performed, in which the effect of the predicted proportions and delta on the power in a noninferiority setting was investigated. The patterns found are discussed in terms of the practical relevance within the cost-minimization framework. RESULTS: Sensitivity analyses show different patterns of results for both null-hypotheses. The differences in these results originate from the way delta is expressed. By expressing delta as absolute difference, power grows quite fast when sample proportions are smaller than expected. In the case of a proportional delta at small sample proportions, the power to establish noninferiority remains low. CONCLUSIONS: To obtain valid results from a cost-minimization study, care has to be taken to adapt the correct methodology for noninferiority testing in clinical outcomes. Defining delta in terms of absolute differences between treatments can lead to obscured results. Although conservative, the expression of delta as a proportion of the effectiveness of the treatment as usual is found to be closer to clinical practice. The inflated delta, resulting from smaller clinical effects than expected when absolute formulation is applied, thus can be avoided.

Cost Control↗