Right heart pressure determination by Doppler in infants with tricuspid regurgitation

Doppler and direct measurements of right ventricle to right atrial pressure drop were made during cardiac catheterisation on 28 occasions in 26 infants with congenital heart disease. Age was 10 days to 12 months (median 4.5 months), and weight was 3.1 to 9.0 kg (median 4.7 kg). We measured peak velocity of tricuspid regurgitation by continuous wave Doppler, and the pressure drop was calculated using the modified Bernoulli equation (delta p = 4v2). There was a high correlation (r = 0.95) between direct and Doppler measurements. Doppler values tended to underestimate the right ventricle to right atrial pressure drop, but this was not of clinical significance (mean 2 mm Hg). The 95% confidence interval for the Doppler velocity was -0.41 to +0.26 m/sec, and was consistent across the range of pressures studied. Variability between observers was tested, by two observers performing sequential paired examinations on 16 newborn babies with tricuspid regurgitation. The coefficient of repeatability was 6.3 mm Hg (95% confidence interval 4.7 to 9.5 mm Hg) or 0.26 m/sec (0.18 to 0.50 m/sec). This method of right ventricular pressure estimation, validated previously only in older children and adults, is a reproducible and accurate technique in infants with tricuspid regurgitation.     

Clinical Implications of Blood Substitutes

Red cell substitutes are developing rapidly and progressing in their clinical testing. The original concept of a shelf storable oxygen carrying solution for use in trauma and other emergency situations still remains valid. Of interest is the potential for red cell substitutes to be used in other areas of surgery, traditionally the realm of autologous transfusion. This article describes some of the logic behind defining which areas of application are potentially useful in the surgical arena.     

Failure of ablation of a mediastinal parathyroid adenoma by repeated contrast staining

In a patient with primary hyperparathyroidism an attempt was made to ablate a middle mediastinal parathyroid gland by forceful staining with radiographic contrast material. The gland was stained on two separate occasions, two weeks apart. Both times the serum calcium level temporarily fell to the normal range but reverted to abnormal levels. The patient ultimately required surgery for correction of hypercalcemia. The mechanism of staining and possible reasons for failure as well as potential complications are discussed.     

Transplantation of cultured bovine corneal endothelial cells to rabbit cornea: clinical implications for human studies.

Rabbit corneas denuded of their endothelium were coated with bovine corneal endothelial cells (from steers) previously maintained in tissue culture for short (20 generations) or prolonged (200 generations) periods. When grafted back into female rabbits, the corneal buttons remained clear and showed no edema. In contrast, denuded corneas coated with bovine keratocytes and grafted into rabbits became opaque and edematous within 7 days and remained so thereafter. Bovine corneal endothelial cells of the grafted corneas, which had remained clear for over 100 days, proliferated actively when put back into tissue culture. The corneal endothelial cells of the graft were characteristic of the male (XY). The chromosome number of the endothelium of the recipient rabbit was 2n = 44 with sex chromosomes characteristic of the female (XX). Results of the karyotype analysis show that there was no invasion of the corneal button by the recipient endothelium and, conversely, no invasion of the recipient endothelium by the endothelium on the corneal button. These results demonstrate that cultured corneal endothelial cells remain functional in vitro and can replace a damaged or nonfunctional endothelium in vivo.     

Frequencies of inherited organic acidurias and disorders of mitochondrial fatty acid transport and oxidation in Germany

The lack of epidemiological data on the frequency and/or burden of organic acidurias (OA) and mitochondrial fatty acid transport and oxidation disorders (mtFATOD) is one reason for hesitation to expand newborn screening (NBS) by tandem mass spectrometry (MS-MS). From 1999 to 2000, the frequency of ten potentially treatable OA and mtFATOD was assessed by active nation-wide surveillance on cases presenting with clinical symptoms using the German Paediatric Surveillance Unit (ESPED) system. Case ascertainment was complemented by a second independent source: 3-monthly inquiries in the metabolic laboratories performing secondary selected screening for OA and mtFATOD. Frequency estimates for clinically symptomatic cases older than 7 days in a birth cohort of 844,575 conventionally screened children was compared to the frequency found in a cohort of 382,247 screened by MS-MS in Bavaria and Baden-Württemberg. The overall frequency of the ten conditions considered was 1:8,000 (95% CI 1:11,000–1:6,000) by MS-MS as compared to 1:23,000 (95% CI 1:36,000–1:17,000) in symptomatic cases presenting mainly with metabolic crisis. The contributions of medium-chain acyl-CoA dehydrogenase deficiency (MCADD), other mtFATOD and OA were 29, 4 and 13 among the 46 cases identified by MS-MS, and 19, 1 and 13 among the 33 clinically symptomatic cases, respectively. Acute metabolic crisis, with a lethal outcome in four patients, was reported for 22/33 clinically symptomatic cases. No clinically symptomatic cases were reported from cohorts with screened by MS-MS. Conclusion: ten potentially treatable organic acidurias and mitochondrial fatty acid transport and oxidations disorders were more common than phenylketonuria with organic acidurias accounting for 28% of the cases detected by newborn screening and 39% of the cases identified on high risk screening. These conditions were related to considerable morbidity and mortality. Considerations for their inclusion in expanded newborn screening programmes might be warranted.Abbreviations ESPED Erhebungseinheit für seltene pädiatrische Erkrankungen in Deutschland (German Paediatric Surveillance Unit) - MCADD medium-chain acyl-CoA dehydrogenase deficiency - MS-MS tandem mass spectrometry - mtFATOD mitochondrial fatty acid transport and oxidation disorders - NBS newborn screening - OA organic acidurias     

Use of an oxygen therapeutic as an adjunct to intraoperative autologous donation to reduce transfusion requirements in patients undergoing coronary artery bypass graft surgery

BACKGROUND: The benefits of intraoperative autologous donation (IAD) in reducing the need for allogeneic blood transfusion in surgery have been debated for several years. The purpose of this study was to determine if IAD alone or in conjunction with hemoglobin raffimer (HR) confers a reduction in red cell or blood component transfusion compared with results in standard clinical practice. STUDY DESIGN: The Phase III clinical trial was a multicenter, randomized, double-blind study to determine the efficacy and safety of HR versus 10% pentastarch when used to facilitate IAD in 299 patients undergoing primary coronary artery bypass grafting. The patients received HR or pentastarch as an adjunct to IAD immediately before cardiopulmonary bypass. Results were compared with transfusion requirements for 150 matched patients in the reference group. RESULTS: The frequency of allogeneic RBC transfusion in the HR, pentastarch, and reference groups was 56%, 76%, and 95%, respectively. The number of allogeneic red cell units used was 49 in the HR group, 104 in the pentastarch group, and 480 in the reference group (p < 0.001). The total number of non-RBC units administered was 150 in the HR group, 238 in the pentastarch group, and 270 in the reference group. CONCLUSIONS: In this study, patients treated with HR in conjunction with IAD received fewer transfusions overall and a lower volume of allogeneic RBCs and non-RBC allogeneic blood products than did the two comparison groups. This confers a real benefit on the overall blood supply by decreasing use and increasing availability.