Iodixanol in paediatric gastrointestinal imaging: safety and efficacy comparison with iohexol.

Iodixanol (Visipaque) is a dimeric, non-ionic iodinated contrast medium that is isotonic with blood at all clinically relevant concentrations. Iodixanol was compared in a randomized, double blind, parallel group, phase III multicentre trial with a monomeric, non-ionic contrast medium, iohexol (Omnipaque), at two concentrations assessing safety, tolerability and radiographic efficacy during contrast enhanced gastrointestinal radiography examinations of children. 154 children entered the trial; 152 formed the safety population and 147 the efficacy population. All examinations were performed following standard departmental practice. Children were assigned into either a high or low concentration group (iodixanol, 150 mgI ml(-1) and 320 mgI ml(-1) vs iohexol, 140 mgI ml(-1) and 300 mgI ml(-1)). The primary outcome measure for efficacy was the overall quality of visualization, which was assessed using a 100 mm visual analogue scale (VAS). The secondary efficacy variables assessed were quality of contrast opacification, mucosal coating and overall quality of diagnostic information. Safety evaluation involved patient follow-up for at least 48 h. Taste acceptance was also assessed. There was no statistically significant difference between the two contrast media with regard to the primary and secondary efficacy variables assessed, although higher ratings were observed for iodixanol. The 100 mm VAS score overall was 86 mm for iodixanol and 82 mm for iohexol (95% confidence interval -2.56, 10.42). The frequency of adverse events was lower for patients receiving iodixanol. Adverse events, mainly diarrhoea, occurred in 12 patients (16.2%) in the iodixanol group and 28 patients (35.9%) in the iohexol group. This reached statistical significance (p=0.006). Overall, iodixanol is well suited for examinations of the gastrointestinal tract, giving good efficacy results and fewer adverse events than iohexol.

Iodixanol is readily eliminated by hemodialysis.

UNLABELLED: PURPOSE, MATERIAL AND METHODS, AND RESULTS: The dialyzability of the high-molecular X-ray contrast medium iodixanol was examined in an in vitro hemodialysis model using two different hollow fiber membranes: one high-flux (poly-sulfone) membrane and one intermediate-flux (cellulose triacetate) membrane. Blood flow was 200 ml/min and membrane area 1.3 m2. The dialyzer clearance of iodixanol dissolved in a mixture of leukocyte-filtered SAG-M blood and compatible citrate plasma was 134.2 +/- 3.6 ml/min for the polysulfone membrane and 113.0 +/- 3.6 ml/min for the cellulose triacetate membrane. CONCLUSION: Iodixanol is readily dialyzed through commercial high-flux membranes.

[Ultrasonography and neuropathological findings in premature infants]. / Ultrasonografi og neuropatologiske funn hos premature barn.

At most maternity units all premature infants are investigated by cranial ultrasonography as a routine. We examined the correlation between autopsy findings and ultrasound examination in 30 premature newborn. The ultrasound examination demonstrated bleeding in 17 (65%) of the 26 cases where autopsy had revealed bleeding. In these 17 patients good correlation was found between the degree of bleeding in the two examinations (ultrasonography and autopsy). In ten patients autopsy showed periventricular leucomalacia, but ultrasonography showed this condition in only two of these. In five cases bleeding made the examination and interpretation of the ultrasound findings difficult. In three patients ultrasonography was thought to be normal, while autopsy demonstrated periventricular leucomalacia.

Effect of iopentol on renal function and its use for calculation of glomerular filtration rate in children.

Nineteen children received 99mTc-DTPA for renography. The next day they received a simultaneous injection of the non-ionic contrast medium iopentol for urography and another injection of 99mTc-DTPA. The glomerular filtration rate (GFR) was estimated from the plasma elimination of 99mTc-DTPA as well as iopentol. Serum concentrations of creatinine and beta 2-microglobulin, and urine concentrations of creatinine, beta 2-microglobulin, alkaline phosphatase, N-acetyl-glucosaminidase, and albumin were determined. A significant reduction (12 +/- 3%) of GFR was observed after the injection of iopentol, without a subsequent rise in serum creatinine or beta 2-microglobulin. The urinary excretion of albumin and beta 2-microglobulin remained unchanged, while the excretion of alkaline phosphatase and N-acetyl-glucosaminidase was significantly increased after the urography, indicating some tubular effects of iopentol. Iopentol caused few and mild adverse events, the diagnostic yield was high, and the small changes in the renal tubular function parameters are presumed to be without clinical importance. The observed depressive effect on the GFR demands further investigations before iopentol can be recommended as a GFR-marker in children.

Congenital pulmonary arteriovenous fistula.

Pulmonary arteriovenous fistula wherein the malformation has venous drainage directly to the left atrium is a rare anomaly. Two case reports present such unusual arteriovenous malformations successfully treated by surgery.

[Better results with early surgical intervention in biliary atresia. Icterus in infants older than 14 days should be investigated!]. / Tidlig kirurgisk behandling bedrer resultatene ved gallegangsatresi. Icterus hos spedbarn etter 14 dagers alder skal utredes!

The average survival of patients with biliary atresia that remains untreated is 12 months. Early portoenterostomy, and subsequent liver transplantation if necessary, have improved survival dramatically. The success rate after portoenterostomy is inversely related to age at primary operation, and the results after liver transplantation are best in children who receive the transplant after the age of one year. Thus, early portoenterostomy will buy time and bring the patient into a group with a better prognosis if liver transplantation is performed later. Among infants older than two weeks of age with neonatal jaundice, patients with conjugated hyperbilirubinemia must be identified and referred for investigation. In this case ultrasonography is most important for discovering biliary atresia.

Skeletal maturation during thyroxine treatment in children with congenital hypothyroidism.

The aim of this investigation was to study if bone age development (assessed by the Greulich & Pyle atlas) was related to L-thyroxine treatment in 47 children with congenital hypothyroidism, treated early and according to general recommendations. In spite of frequent delay in skeletal maturation at diagnosis, the delay in mean bone age at a mean chronological age of 1.5 years was slight (0.5 months), and 30% of the variation in bone age SD score (SDS) at 1.5 years was accounted for by the dose of L-thyroxine and serum thyroxine during the first year. The children with a bone age within +/- 1 SDS had a prescribed mean dose of L-thyroxine per kg body weight from 3 to 12 months of age of 5.4 +/- 1.7 micrograms/kg/day, and their mean serum thyroxine concentration during the first year was 175 +/- 29 nmol/l. We conclude that bone age at 1.5 years of age was positively correlated with the dose of L-thyroxine and the serum thyroxine concentrations during the first year. This supports the general use of bone age assessments as a complement to other treatment variables in the follow-up of children with congenital hypothyroidism.

Progress in the treatment of biliary atresia: a plea for surgical intervention within the first two months of life in infants with persistent cholestasis.

During the period 1984-1991, 21 infants with biliary atresia were treated with Kasai's portoenterostomy. The median survival in infants operated on before the age of 60 days (55 (range 5-82) months) was significantly longer than the survival of children operated on after the age of 60 days (15 (1.5-38) months). At present there are 10 survivors with a median age of 54 (17-96) months; 6 with portoenterostomy and 4 after liver transplantation. Eight patients died of progressive liver failure and 3 died of causes not related to biliary atresia. Apart from blood tests, ultrasonography was the most important investigation before laparotomy in infants with cholestatic jaundice. Scintigraphy and liver biopsy added no further decisive information. Because early diagnosis and surgical treatment is important, only the well documented presence of a normal gallbladder can warrant postponement of an operation.

The clearance of iohexol as a measure of the glomerular filtration rate in children with chronic renal failure.

The plasma clearances of technetium-99m-labelled DTPA ([99Tcm]-DTPA) and the non-ionic contrast medium iohexol were estimated in 11 children with chronic renal failure for determination of the glomerular filtration rate (GFR). Equal values were obtained with the two substances provided plasma sampling was simultaneous, but when plasma was sampled within 3.5 h after injection of iohexol and [99Tcm]-DTPA the GFR was overestimated by more than 50%. For clearance values below 20 ml min-1 1.73 m-2, valid GFR estimates were obtained both from two plasma samples taken 3 h and 24 h after the injection of iohexol and from a single plasma sample taken 24 h after the injection.

A single plasma sample method for estimation of the glomerular filtration rate in infants and children using iohexol, I: Establishment of a body weight-related formula for the distribution volume of iohexol.

This study was performed in order to develop a method for estimation of the glomerular filtration rate (GFR) from a single plasma sample based upon the plasma disappearance rate of the non-ionic contrast medium iohexol. The apparent distribution volume for iohexol was measured in 100 infants and children and used for establishment of a weight-related empirical formula for the distribution volume. Using the distribution volume obtained by this formula, a preliminary GFR was calculated from the iodine concentration measured in a plasma sample taken 3 h after injection of iohexol. When this estimate was corrected by another empirically established correction factor, a high degree of agreement was found between a GFR reference method and the 3-h single plasma sample method. In another group of 13 children the 3-h single plasma sample GFR was estimated twice with a 2-day interval, and the day-to-day variations were found to be similar to those obtained with other standard methods.

A single plasma sample method for estimation of the glomerular filtration rate in infants and children using iohexol, II: Establishment of the optimal plasma sampling time and a comparison with the 99Tcm-DTPA method.

The glomerular filtration rate (GFR) can be determined from the plasma disappearance rate of the non-ionic contrast medium iohexol. A preceding study established the empirical formulae enabling the development of a single plasma sample method for estimation of GFR in infants and children. In the present study the validity of these empirical formulae was confirmed in examinations in 143 patients. The results of the single plasma sample method were similar to those of a standard 99Tcm-DTPA method, and also with those of a two plasma sample iohexol method. Evaluation of the results obtained with plasma sampling 1 h, 2 h, 3 h and 4 h after the injection of the contrast medium showed that the optimal sampling time was about 3 h after the injection.

[Cerebral hemorrhage in newborn infants. A 1-year case load]. / Hjerneblødning hos nyfødte. Et ettårsmateriale.

Over a period of one year (1984) routine cerebral ultrasonography was performed on all premature infants (gestational age less than 37 weeks), all infants weighing less than 2,250 grams at birth and all other infants with clinical indications such as severe asphyxia, seizures etc. Altogether 209 infants were examined. The overall incidence of intracranial hemorrhage (ICH) was 18.7% (39 infants), and was 32.1% in premature infants and 6.2% in term infants. Most infants developed ICH before the third day of life. A strong correlation was found between gestational age and ICH, and between respiratory disease and ICH. No correlation was noted between ICH and parameters related to birth or maternal history. There was a higher incidence of ICH in transported infants than in inborn infants. Only four patients who died from large parenchymal bleedings showed clinical symptoms of ICH.

Glomerular filtration rate estimated by X-ray fluorescence technique in children: comparison between the plasma disappearance of 99Tcm-DTPA and iohexol after urography.

The total plasma disappearance of the non-ionic contrast medium iohexol was determined by X-ray fluorescence technique following intravenous urography in 10 children aged between 2 and 13 years. For comparison the plasma disappearance of 99Tcm-DTPA was estimated both 2 days before and simultaneously with the iohexol study. High correlations between the three sets of data were found and no change in the glomerular filtration rate was detected following injection of contrast medium. It was also found that reliable estimates of the glomerular filtration rate can be obtained from two plasma samples of 1 ml each, taken 3 h and 4 h after the injection of the contrast medium.

Influence of urography on renal function in children. A double blind study with metrizoate and iohexol.

Thirty-two children were given either metrizoate or iohexol for urography in a double blind study. Mild to moderate adverse reactions were observed in all patients receiving metrizoate (15/15) and in 4 receiving iohexol (4/17). Alkaline phosphatase in urine was significantly increased 4 hours after the injection of both media, but had returned to pre-injection levels 16 hours later. The excretion of beta 2-microglobulin and albumin was not altered. In 9 children in the metrizoate group and 11 in the iohexol group the glomerular filtration rate (GFR) was determined before urography by the single injection 99Tcm-DTPA-technique and 3 to 4 hours after urography by measuring the plasma disappearance of the contrast medium with the x-ray fluorescence technique. No reduction of GFR was observed.

Surgical repair of aortico-left ventricular tunnel (ALVT).

ALVT is a very rare congenital malformation. Until 1983 a collective review reported only 37 cases published. A 5-month-old girl with a body weight of 5.5 kg was referred for cardiomegaly and cardiac murmur. 2D-echo revealed the diagnosis which was later confirmed by angiography. The child was then operated upon with extracorporeal circulation using deep hypothermia (20 degrees C). The aortic orifice of the tunnel was closed with 3 pledget reinforced sutures. Cross-clamp time was 17 min. Electromagnetic flowmetry suggested an insufficiency of 78% preoperatively, and postoperatively this was reduced to 6%. Angiography was performed two weeks postoperatively, revealing mild valvular aortic insufficiency. She was discharged from the hospital 15 days postoperatively. ALVT should be corrected surgically as soon as the diagnosis is made.

Iohexol and metrizamide for urography in infants and children.

The new nonionic contrast medium iohexol, was compared with metrizamide in a double blind investigation. Urography was performed in 40 children below 6 years of age. Adverse reactions were negligible. A small decrease in erythrocyte volume fraction (hematocrit) values after the injection was found in both groups. Excellent films were obtained in most patients and no difference in diagnostic quality between the two media was observed.