ABSTRACT
Simultaneous measurements of arterial, transcutaneous, and peak expired carbon dioxide were obtained in 24 newborn infants receiving mechanical ventilation during the first week after birth. Two calibration algorithms designed to estimate PaCO2 from the noninvasive measurements were then examined. Both approaches entailed finding a statistical relationship by which future noninvasive measurement could be used to estimate the arterial value rather then measuring it directly. The first utilized the difference between the initial paired measurements (an in vivo calibration); the second used the mean difference between all measurements in the population. Adjusted tcPCO2 measurements by either the in vivo calibration or by the population-based factor led to estimates of PaCO2 with 95% confidence limits of +/- 6 to +/- 8 torr. In contrast, this degree of precision for the peak expired CO2 measurement was only possible using the in vivo calibration method. The use of an airway adaptor for PCO2 measurement led to CO2 retention in more than half of the infants. Transcutaneous monitoring had no significant effects on the infants, but was hampered by excessive drift and erratic sensitivity of the electrodes.
Subject(s)
Carbon Dioxide/blood , Critical Care , Respiratory Distress Syndrome, Newborn/blood , Blood Gas Analysis/instrumentation , Blood Gas Analysis/methods , Carbon Dioxide/analysis , Critical Care/methods , Humans , Infant, Newborn , Partial Pressure , Peak Expiratory Flow Rate , Respiration, Artificial , Respiratory Distress Syndrome, Newborn/metabolism , Respiratory Distress Syndrome, Newborn/therapy , Skin/blood supply , Spectrophotometry, InfraredABSTRACT
In a May, 1975, outbreak, 147 adolescents, ages 12 to 19 years, were identified as having measles by a physician or school nurse. One junior high school, with an enrollment of 1,122, contributed 131 of the cases. Of the 147 students, 54 were seen by physicians who also supplied their immunization records; 19 of 54 (35%) had received live measles virus vaccine without measles immune globulin, after age one year. The remaining 35 received: killed virus vaccine only (1), K + L (4), L + MIG (4), L at less than 1 year of age (4), L + ? MIG (4), immune serum globulin only, for exposure (6), no vaccine but history of measles previously (9); history uncertain (3). Hemagglutination-inhibition antibody titers were consistent with the diagnosis of acute measles in 11 children. No index case was identified and no secondary cases occured within the families of the 54 cases. This measles outbreak among seemingly immunized adolescents raises a serious question as to the duration of such protection.