Subject(s)
Noonan Syndrome , Child , Genotype , Humans , Noonan Syndrome/diagnosis , Noonan Syndrome/physiopathology , PhenotypeSubject(s)
Aortic Valve Stenosis/complications , Death, Sudden/etiology , Facial Bones/abnormalities , Myocardial Infarction/etiology , Skull/abnormalities , Adolescent , Aorta, Thoracic/pathology , Aortic Valve Stenosis/pathology , Child , Female , Humans , Male , Middle Aged , Myocardial Infarction/pathology , Myocardium/pathology , SyndromeABSTRACT
Sixteen newborn infants with severe pulmonary parenchymal disease and profound hypoxemia were treated with mechanical ventilation, alkalinization, and intravenous tolazoline. Eight infants responded within two hours of initiation of tolazoline therapy with a rise in Pao2 by at least 100% of pretreatment values (mean = 188%, range = 103 to 427%). Eight infants showed little or no change in Pao2 with administration of tolazoline. Echocardiographic evaluation prior to therapy demonstrated marked elevation in both left (LPEP/LVET = 0.52 +/- 0.13) and right (RPEP/RVET = 0.56 +/- 0.08) ventricular systolic time intervals in the eight infants who subsequently responded to tolazoline. Systolic time intervals in nonresponders were within the normal range (LPEP/LVET = 0.37 +/- 0.03, RPEP/RVET = 0.33 +/- 0.04) and were not significantly different from those observed in a control group of 15 infants with pulmonary disease requiring mechanical ventilation but without hypoxemia. Following tolazoline therapy, systolic time intervals in all eight responders fell to normal values. Echocardiography can provide a safe, noninvasive method for identifying those infants with primary pulmonary disease and severe hypoxemia who could be expected to benefit from tolazoline therapy, thereby avoiding tolazoline side effects in infants for whom tolazoline therapy can be predicted to be of little benefit.
Subject(s)
Echocardiography , Hypoxia/complications , Infant, Newborn, Diseases/diagnosis , Lung Diseases/complications , Evaluation Studies as Topic , Humans , Hypoxia/drug therapy , Infant, Newborn , Infant, Newborn, Diseases/drug therapy , Lung Diseases/drug therapy , Tolazoline/therapeutic useABSTRACT
The administration of 160 mg of propranolol during pregnancy, labor, and delivery was associated with profound hypoglycemia and respiratory depression in a newborn infant. The neonate's plasma propranolol level rose from 40 ng/ml at the time of birth to 90 ng/ml four hours later. This increase in plasma propranolol concentration might be due to redistribution of the drug in the neonate as well as to different elimination mechanisms than in adults. The elevated propranolol level four hours after delivery was not associated with any signs or symptoms of drug toxicity, but drug effect was apparent on the electrocardiogram. The administration of propranolol during pregnancy in doses capable of producing therapeutic maternal blood levels may be dangerous to the neonate.