Hyperoxemia in newborn infants: detection by pulse oximetry.

Pulse oximetry has been proposed as a noninvasive continuous method for transcutaneous monitoring of arterial oxygen saturation of hemoglobin (tcSO2) in the newborn infant. The reliability of this technique in detecting hyperoxemia is controversial, because small changes in saturation greater than 90% are associated with relatively large changes in arterial oxygen tension (PaO2). The purpose of this study was to assess the reliability of pulse oximetry using an alarm limit of 95% tcSO2 in detecting hyperoxemia (defined as PaO2 greater than 90 mm Hg) and to examine the effect of varying the alarm limit on reliability. Two types of pulse oximeter were studied alternately in 50 newborn infants who were mechanically ventilated with indwelling arterial lines. Three arterial blood samples were drawn from every infant during routine increase of inspired oxygen before intratracheal suction, and PaO2 was compared with tcSO2. The Nellcor N-100 pulse oximeter identified all 26 hyperoxemic instances correctly (sensitivity 100%) and alarmed falsely in 25 of 49 nonhyperoxemic instances (specificity 49%). The Ohmeda Biox 3700 pulse oximeter detected 13 of 35 hyperoxemic instances (sensitivity 37%) and alarmed falsely in 7 of 40 nonhyperoxemic instances (specificity 83%). The optimal alarm limit, defined as a sensitivity of 95% or more associated with maximal specificity, was determined for Nellcor N-100 at 96% tcSO2 (specificity 38%) and for Ohmeda Biox 3700 at 89% tcSO2 (specificity 52%). It was concluded that pulse oximeters can be highly sensitive in detecting hyperoxemia provided that type-specific alarm limits are set and a low specificity is accepted.

Vitamin concentrations in very low birth weight infants given vitamins intravenously in a lipid emulsion: measurement of vitamins A, D, and E and riboflavin.

Because total parenteral nutrition with vitamins added to the glucose-amino acid mixture is often associated with a reduction in blood levels of vitamin A (retinol) during the routine treatment of many very low birth weight (VLBW) infants (less than 1500 gm), and because retinol losses in the plastic delivery system can be prevented by adding the vitamins to an intravenous lipid emulsion, seven VLBW infants with a mean birth weight of 900 gm (range 450 to 1360 gm) were given 40% of a unit dose vial, per kilogram of body weight, of a multivitamin preparation (M.V.I. Pediatric) (280 micrograms retinol; 160 IU vitamin D; 2.8 mg tocopherol; 0.68 mg riboflavin) in a lipid emulsion, Intralipid. After treatment with the intralipid-vitamin mixture for 19 to 28 days, plasma vitamin A (retinol) concentrations increased significantly from 11.0 +/- 0.76 (mean +/- SEM) before intralipid to 19.2 +/- 0.97 micrograms/dl after the intralipid-vitamin mixture (p less than 0.01); 25-hydroxyvitamin D concentrations increased from an initial value of 12.6 +/- 2.6 to 20.2 +/- 1.9 mg/dl (p less than 0.01); alpha-tocopherol concentrations increased from an initial value of 0.31 +/- 0.06 to 2.44 +/- 0.13 mg/dl (p less than 0.01); and riboflavin levels increased from 64.1 +/- 7.8 ng/ml to concentrations between 20 and 100 times the initial level. Erythrocyte riboflavin levels increased from 71.8 +/- 14 initially to 166 +/- 41 ng/gm hemoglobin, and erythrocyte flavin-adenine dinucleotide levels increased similarly from 972 +/- 112 initially to 2005 +/- 294 ng/gm hemoglobin. These results show that the addition of M.V.I. Pediatric to Intralipid decreases the extensive in vivo loss of retinol and is associated with an increase in plasma retinol concentrations in VLBW infants. The daily doses of vitamins D (160 IU/kg) and E (2.8 mg/kg) appear sufficient, but the dose of vitamin A (280 micrograms/kg) is insufficient to raise blood levels of all infants into the normal range. The current dose of riboflavin is excessive and may be harmful.

[Neonatal respiratory distress syndrome in Switzerland. Data for 1984 and comparison with 1974]. / Das neonatale Atemnotsyndrom in der Schweiz. Daten für 1984 and Vergleich mit 1974.

In a retrospective study (questionnaire) covering all the neonatal special care units of Switzerland, information was obtained on, the problem cases in 84% of all babies born in 1984. 8.3% were hospitalized. Clinical respiratory distress syndrome (RDS) was diagnosed in 31% of these infants and hyaline membrane disease (HMD) in 6.3%. Mortality in clinical RDS was 7.1% and in HMD 19%. Mortality showed a high degree of correlation with birth-weight. Comparison of the 1984 data with a similar study in 1974 showed no significant change in the incidence of clinical RDS. The incidence of HMD (diagnosis by the same criteria) has fallen from 10.1% to 6.3%. Overall mortality in hospitalized newborns in Switzerland has decreased from 8.8% in 1974 to 4% in 1984.

[Neonatal respiratory distress syndrome in Switzerland--a comparison of a survey and official statistics]. / Das neonatale Atemnotsyndrom in der Schweiz--Ein Vergleich zwischen einer Umfrage und der offiziellen Statistik.

A survey in all neonatal intensive care units in Switzerland showed that most children with a birth weight below 2000 g (identified in the birth statistics) are hospitalised in those units. Also comparison with the official neonatal mortality statistics shows that most neonatal deaths occur in these units. High agreement was found between diagnosis in hospitalised children and those recorded on death certificates. 40% of neonatal mortality in Switzerland are still due to neonatal respiratory distress syndrome.

Is pulse oximetry reliable in detecting hyperoxemia in the neonate?

We tested the hypothesis that hyperoxemia defined as arterial PO2 above 12 kPa can be detected by pulse oximetry using 95% oxygen saturation as the upper limit. Thirty artificially ventilated neonates with an indwelling arterial catheter were studied registrating transcutaneous oxygen saturation (Ohmeda Biox 3700 Pulse Oximeter) and transcutaneous PO2 continuously during a 4-hour period and measuring arterial oxygen saturation and PO2 intermittently. 46 episodes of arterial hyperoxemia were observed. Pulse oximetry had a sensitivity of 30%, detecting 14 of these 46 hyperoxemic episodes, and a specificity of 93%. The accuracy for separating hyperoxemia from normoxemia by pulse oximetry could be improved by shifting the cut-off point from 95% to 92%. With this optimal cut-off point sensitivity was 70% and specificity 62%. We conclude that pulse oximetry is not reliable for detection of hyperoxemia.

[Meconium peritonitis: description of 3 cases with abnormal prenatal ultrasound findings]. / Mekoniumperitonitis: Beschreibung von 3 Fällen mit abnormen pränatalen Ultraschallbefunden.

We describe three children with surgically confirmed meconium peritonitis. All had abnormal prenatal ultrasonographic examinations. The first child showed multiple cysts, the second had hydrops fetalis, and the third had dilated bowel loops. A polyhydramnion was common to all three cases. Of the two children who died, one had cystic fibrosis. It is remarkable that the ultrasonographic findings were different in the three children.