Anaemia may increase the risk of tissue hypoxia in preterm infants. The effect of transfusion on circulation was studied in 33 preterm infants with a mean (SD) gestational age of 29 (5) F45-F48)

Between January 1988 and December 1997 a total of 22 patients (age: 8 days-46 years) were operated for vascular airway compression syndromes with respiratory insufficiency. Vascular anomalies in tracheal compression were double aortic arch in 7 patients, (2 previously operated elsewhere), right aortic arch + left ligamentum arteriosum in 1, and pulmonary artery sling in 3. Three of these patients had secondary long-segment tracheomalacia. Compression of trachea and a main bronchus existed in 2 patients with right aortic arch + left ligamentum. Isolated main bronchus obstruction was present in 9 patients (abnormal insertion of ligamentum arteriosum in 1, status post (s.p.) previous operation for PDA in 4, s. p. surgery for coarctation in 1, right aortic arch + left ligamentum arteriosum in 2, and right lung aplasia + left ligamentum in 1). 3 of these cases had secondary long-segment bronchomalacia. All patients had a complex respiratory anamnesis [long-term intubation in 7, s.p. tracheostomy in 2 (over 3 months - 3 years), and progressive respiratory insufficiency in 13). In tracheal compression, surgical correction included transsection of the underlying ring or sling components (with additional anterior aortic arch translocation in 5 patients resection-reimplantation of left pulmonary artery in 3, segmental tracheal resection in 1, and external tracheal suspension in 2). In the 2 cases with compression of the trachea and a main bronchus, aortic "extension" by a prosthetic tube was necessary. In isolated main bronchus obstruction, surgical decompression basically consisted of transsection of the ligamentum arteriosum or resection of its scarry remnant forming the "corner point" of a compression between aorta and pulmonary artery. In 3 patients with secondary long-segment malacia, additional external bronchus suspension was performed. Effective decompression and re-expansion of the airway segment concerned was achieved, and was demonstrated by intraoperative endoscopy in all patients. There were 3 postoperative deaths (sepsis 2; massive, irreversible edema of the tracheal mucosa 1). Of the 19 surviving patients 16 could be extubated between the 1st and 17th (mean = 7.5) postoperative day. In 1 case the preoperative long-term tracheostomy had to be left in place for inoperable additional laryngeal stricture. 2 patients had to be reoperated (segmental cervical tracheal resection after 5 months for primary long-term intubation-related subglottic stenosis in 1, esophageal decompression for residual dysphagia after 57 months related to a traction phenomenon at the right descending aorta in the other), both with gratifying results. In all other patients clinical, endoscopic, and radiographic examinations (follow-up = 2 months - 6 years) demonstrate good results.

This study was done to compare postnatal alterations in blood viscosity (capillary viscometer) and its determinants: hematocrit, plasma viscosity (capillary viscometer), red cell aggregation (Myrenne aggregometer) and red cell deformability (rheoscope) in the first five days of postnatal life in full-term neonates with early (< 10 s) and late (3 min) cord-clamping. The fetal blood volume of the placenta ("residual placental blood volume") decreased from 52 +/- 8 ml/kg of neonatal body weight after early cord-clamping to 15 +/- 4 ml/kg after later cord-clamping. Neonatal blood volume, calculated as the difference between an assumed total feto-placental blood volume of 115 ml/kg and the measured fetal blood volume of the placenta, was 50% higher in the late cord-clamped infants than in the early cord-clamped infants. Both groups showed similar viscosity, hematocrit and other rheological parameters in cord blood. In the infants with early cord-clamping, the hematocrit decreased from 0.48 +/- 0.04 l/l at birth to 0.43 +/- 0.6 l/l after 24 h (p < 0.05). Whole blood viscosity did not change significantly with age. After late cord-clamping, the hematocrit rose from 0.50 +/- 0.04% at birth to 0.63 +/- 0.05 l/l at 2 h of age (p < 0.005) and dropped to 0.59 +/- 0.5 l/l (p < 0.05) at 24 h. Blood viscosity increased by 40% (p < 0.001) within the first 2 h, but did not change significantly during the following five days. In both groups, plasma viscosity and red cell aggregation increased significantly (p < 0.05) on day 5 due to significant increases in total plasma protein and fibrinogen concentrations (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

The Leboyer birth method requires that the newly born infant is placed on the mother's abdomen and the cord is clamped when it stops pulsating. This investigation was done to study the effect of Leboyer childbirth on neonatal circulation during the first 5 days after birth. Hematocrit, blood viscosity, left and right ventricular output, and cerebral blood flow velocities in the arteria carotis interna, arteria cerebri anterior, and truncus coeliacus were studied in 15 full-term neonates with early (less than 10 seconds) cord clamping and 15 full-term neonates delivered according to Leboyer (cord clamping after 3 minutes) on day 1 (2 to 4 hours after birth) and day 5. The fetal placental blood volume decreased from 42 +/- 8 mL/kg (mean +/- SD) of neonatal body weight after early cord clamping to 19 +/- 7 mL/kg after Leboyer delivery. Neonatal blood volume, calculated from the fetal placental blood volume, was 32% higher in the Leboyer group compared with the early cord-clamped infants. In the infants with early cord clamping, hematocrit, and blood viscosity did not change significantly during the first 5 days. After Leboyer birth, the hematocrit rose from 0.51 +/- 0.05 in cord blood to 0.62 +/- 0.06 at 2 to 4 hours of age, thereby increasing blood viscosity by 32%. Stroke volume, heart rate, cardiac output, left-to-right shunt across the ductus arteriosus, and blood flow velocity in the truncus coeliacus were similar in both groups and did not change during the first 5 days.(ABSTRACT TRUNCATED AT 250 WORDS)