A randomized trial of heparin and saline for maintaining intravenous locks in neonates.

PURPOSE: To determine the effects of saline, heparin 2 units (U) per ml saline, and heparin 10 U/ml saline flush solutions on the duration of intravenous (i.v.) locks and the incidence of i.v. infiltration in neonates. DESIGN: Randomized double-blind experiment. SETTING: Tertiary-care nursery. PARTICIPANTS: Neonates (N = 90) hospitalized at birth in the intensive, intermediate care, or newborn units. MAIN OUTCOME MEASURES: Total hours from the time the i.v. was inserted to the time the i.v. was removed; hours from the time the i.v. was first flushed to the time the i.v. was removed; number of i.vs. removed because of infiltration. RESULTS: No statistical or clinical differences between the three groups for duration of i.v. nor for incidence of complications. CONCLUSIONS: The use of heparin in i.v. lock flush solution did not affect the duration of i.v. locks nor the incidence of infiltration in neonates.

Elimination of antithrombin III concentrate in healthy pregnant and preeclamptic women with an acquired antithrombin III deficiency.

The activity elimination half-life of heat-treated antithrombin III (AT III) concentrate was studied in 5 healthy pregnant and 5 preeclamptic women with a documented AT III deficiency. Healthy pregnant women received 1500 units over 20 minutes. Serial blood specimens were obtained over the next 12 hours. The mean (+/- SEM) activity elimination half-life of AT III was 29.4h +/- 3.4h. Preeclamptic subjects had a mean baseline AT III activity of 70.5 +/- 2% (range 61 to 75%). Their activity eliminator half-life after 3000 units of AT III concentrate was 8.5 +/- 1.2h. There was a direct relationship between the pre-concentrate AT III activity level and the AT III activity elimination half-life (r = 0.79, p = 0.01) for all subjects. Based upon parameters calculated from the first infusion, the AT III activity of preeclamptic subjects was maintained by a constant infusion at approximately 100% for 96h. At the conclusion of the infusion, the activity elimination half-life was again measured. A dramatic increase in the activity elimination half-life was demonstrated (433.6h). We conclude that the activity elimination half-life of AT III concentrate is increased during normal pregnancy and further increased in preeclamptic women with an acquired deficiency.

The effect of intravascular transfusion on umbilical venous pressure in anemic fetuses with and without hydrops.

Human fetal umbilical venous pressure was measured during 20 intravascular transfusions performed for treatment of hemolytic anemia. The mean (+/- 1 SEM) gestational age at the time of transfusion was 29.3 +/- 1 weeks and the mean beginning hematocrit was 27% +/- 2%. The mean volume of infused packed red blood cells (70% hematocrit) was 90.3 +/- 7 ml. The mean hematocrit at completion of the procedure was 48% +/- 1%. In nonhydropic fetuses umbilical venous pressure rose progressively from 6.7 +/- 1 mm Hg at the start of transfusion to 10.9 +/- 1 mm Hg at the completion of transfusion (p less than 0.002). However, most fetuses who began the infusion with a normal umbilical venous pressure ended the transfusion with a normal umbilical venous pressure (less than 10 mm Hg). Fetuses with immune hydrops (n = 2) had elevated umbilical venous pressure values before the initiation of transfusion therapy when compared with the first transfusion of nonhydropic fetuses (12.5 +/- 0.5 vs. 5.7 +/- 1 mm Hg, p = 0.01). However, the umbilical venous pressure measurements declined into the normal range within 24 hours of the first transfusion; this normalization was too rapid to be explained by the reversal of liver hypertrophy or portal hypertension. There was no demonstrable relationship between the rise in umbilical venous pressure and either the gestational age, the volume transfused, or the rise in hematocrit. This study demonstrated: (1) In terms of the umbilical venous pressure, direct intravenous infusion of the human anemic fetus is well tolerated; (2) the elevated umbilical venous pressure associated with immune hydrops can correct rapidly with red blood cell replacement.

Normal values for human umbilical venous and amniotic fluid pressures and their alteration by fetal disease.

Umbilical venous and amniotic fluid pressures were measured in 68 human pregnancies at the time that cordocentesis was performed. Normal umbilical venous pressure was unrelated to gestational age and remained within a tight range (5.3 +/- 2.3 mm Hg, mean +/- SD). Fetuses with an elevated umbilical venous pressure had disorders consistent with either hepatomegaly or congestive heart failure. Umbilical venous pressure was significantly increased before treatment in two fetuses with immune hydrops; it rapidly declined with treatment. Neither gestational age nor umbilical venous pressure was significantly different in the groups that received and did not receive pancuronium. There was a strong relationship between amniotic fluid pressure and gestational age in normal pregnancy (r = 0.54, p less than 0.0001). Women with hydramnios had amniotic fluid pressures greater than control subjects (p = 0.0007). This investigation documents normal human amniotic fluid and fetal umbilical venous pressures. These measurements are altered by disease and may prove to be of diagnostic and therapeutic value in the future.

Albumin and beta 2-microglobulin excretion in patients on long-term lithium treatment.

Albumin and beta 2-microglobulin excretions were studied in 85 unselected patients treated with lithium for more than 6 months. In 15 patients a lithium-induced impaired renal concentrating ability was found, 13 of these patients revealed a chronic interstitial nephropathy on renal biopsy. There was no significant increase in albumin excretion, and a markedly increased beta 2-microglobulin excretion was seen in only 1 patient. This study supports the hypothesis that the lithium-induced renal lesion in confirmed to the distal part of the nephron.

Chronic interstitial nephropathy in patients on long-term lithium treatment.

One-hundred and ten patients treated with lithium for more than six months were studied in order to determine the prevalence of lithium induced nephropathy. Eighteen of 69 patients (26 per cent) who had been treated for more than two years presented a chronic interstitial nephropathy characterized by a marked decrease in renal concentrating ability with a disproportionate preservation of glomerular filtration rate. Histologically, increased amounts of fibrotic tissue in the medulla and the cortex were found together with tubular atrophy. In 40 per cent of the patients who underwent renal biopsy, cystic formations in the cortex were found. The impairment of renal concentrating ability could be related to the duration of lithium treatment and the degree of tubular damage correlated with the degree of impairment of renal concentrating ability. Lithium induced, chronic nephropathy is a rather common complication of long-term lithium treatment and reduces the patients capacity to regulate water and electrolyte metabolism. As water and electrolyte loss appears to precede the slowly progressing lithium intoxication, the main hazard of lithium induced nephropathy is lithium intoxication.