Patient injuries in response to anaesthetic procedures: cases evaluated by the Danish Patient Insurance Association.

BACKGROUND: In response to medical treatment, side-effects may occur and the patient may be injured. In Denmark, a patient is entitled to raise a claim for financial compensation and the validity of the claim which, based on defined criteria, is decided by the independent Patient Insurance Association (PIA). In this study, we investigated the files of the patients who were given financial compensation because of an injury caused by an anaesthetic procedure. We wanted to find the sort of injuries and the anaesthetic procedures involved and the size of financial compensation. METHODS: A retrospective study of the PIA database from 1996 to 2002 concerning the speciality anaesthesiology. RESULTS: From 1996 to 2002, 18,917 patients made a claim and out of these 916 files were related to anaesthetic procedures, of which 374 cases resulted in financial compensation. In the same period, it is estimated that the total number of anaesthetic procedures was approximately 400,000 per year in Denmark. The primary causes for financial compensation were nerve lesions in response to regional anaesthesia (epidural, spinal, peripheral nerve blockade; n = 132), body positional-related injuries (n = 100), complications due to intravascular catheters or needles (n = 39) and teeth damage during airway handling (n = 31). After anaesthesia, 12 patients' brain functions were impaired probably as a result of prolonged peri-operative hypotension and hypoxaemia. Death occurred in 21 cases. The average financial compensation was 21,500 euros (0.3% of the total amount from all cases) and in 13 cases the injury induced severe patient disability and therefore the compensation was above 1 million DKr. equal to 150,000 euros. CONCLUSION: In the 6-year period 1996-2002, 374 patients were given in total 8.0 million euros in financial compensation for an injury caused by an anaesthetic procedure. Some anaesthetic complications may result in severe disability whereby the financial compensation to the suffering patients is high. In this study, we estimate that approximately approximately 0.2 per thousand of all patients receiving anaesthesia may develop complications that entitle them to financial compensation.

Formation of phosphate-containing calcium fluoride at the expense of enamel, hydroxyapatite and fluorapatite.

During the caries process complex reactions involving calcium, phosphate, hydrogen and fluoride ions as main species take place. In this study the precipitation and dissolution reactions occurring in suspensions of enamel, hydroxyapatite (HAP) and fluorapatite (FAP) on addition of fluoride were investigated under well-defined conditions. pH and pF were monitored; calcium and phosphate concentrations were measured at selected times; the solid phases were examined by infra-red, X-ray diffraction and transmission electron microscopy. Precipitation of phosphate-containing calcium fluoride crystals, CaF2(P), can cause severe reduction in the calcium ion concentration and release of hydrogen ions from the precipitated phosphate. These reactions result in considerable dissolution of enamel, HAP and even of FAP. More of the added mineral dissolves with 50 mmol/l fluoride than with 10 mmol/l fluoride, mainly due to the greater reduction in calcium ion concentration. This work shows that phosphate-containing calcium fluoride is most likely an important compound to be considered in the caries process.

Assessment of renal function from plasma urea and plasma creatinine in children.

The diagnostic value of plasma urea and plasma creatinine, used separately and in combination, for assessment of renal function in children was determined from simultaneously measured values of plasma urea, plasma creatinine and glomerular filtration rate (GFR) in 357 children with different nephro-urological disorders. GFR was determined from the total [51Cr]EDTA plasma clearance measured by a reliable single injection method. Four levels of renal function (with the limits expressed as % of the age-dependent normal mean standard GFR) were defined: normal (greater than 75%); moderately decreased (75-52%); considerably decreased (51-28%); and severely decreased (less than 28%). Plasma concentrations of urea (mmol/l) and creatinine (expressed as a percentage of age-dependent normal mean value) were graded into low and high normal, moderately increased, considerably increased and severely increased values. Only by using plasma urea and plasma creatinine in combination all four levels of renal function could be predicted in the individual child with a high degree of certainty (probability 0.94-1.00). The results of the study indicate that the plasma concentration of urea and creatinine should be measured simultaneously, the results being used in combination with due consideration to the variability of plasma creatinine with age. By this procedure the majority of children, i.e. approximately 80%, with nephro-urological disorders who are referred to a paediatric clinic can have their level of renal function predicted with a high degree of certainty. Using plasma urea and plasma creatinine separately the corresponding figure is 50 and 60%, respectively.