Thomas H. Gardner

Exchange transfusion in neonatal myasthenia

TRANSIENT NEONATAL MYASTHENIA OCCURS in 10 to 15% of infants of myas then ic mothers . The illness is character ized by hypotonia , feeding difficulties, and facial weakness, which usually resolve in four to six weeks. Many infants require in te rmi t ten t ant ichol ines terase medication to assure adequa te oral nutr i t ion, bu t f l ank respiratory fai lure is rare. W h e n a severely affected, respiratorbound in fan t failed to respond to ant ichol ines terase medicat ion, exchange t ransfusion produced a significant improvemen t in strength.

Pulmonary complications of hyperventilation therapy for persistent pulmonary hypertension.

Hyperventilation has become a primary therapeutic modality in the management of neonates with persistent pulmonary hypertension (PPH). Of 51 PPH infants undergoing hyperventilation therapy, 45% developed pneumothorax. The subgroup which developed pneumothorax was exposed to assisted ventilation for significantly longer time periods and at higher peak inspiratory pressures. They were also exposed to longer periods of oxygen therapy at higher oxygen concentrations. Survival in the pneumothorax group was significantly lower.The incidence of bronchopulmonary dysplasia (BPD) in the 35 survivors was only 6%. These data indicate that the use of hyperventilation to treat PPH is associated with a significant incidence of pneumothorax but a low incidence of BPD.

Coagulation changes in the newborn with respiratory failure

Abstract These studies involved clinical and laboratory investigations in 24 infants. Eleven healthy premature and term babies were used to establish a normal laboratory range. Thirteen consecutive infants requiring ventilatory assistance were compared to the normal group according to a broad range of clinical and laboratory measurements. Clinical parameters of the two groups were obviously different. However, the laboratory measurements of clotting appears to be close in each group only within the first 12 hours of extrauterine life. The fibrinolytic system appeared to be the most significantly activated parameter as seen by the initial deviations of the plasminogen and fibrin split products in the ill infants. Related changes in complement C′3 and C′4 were also noted. Two of the study infants survived and their data is shown for prognostic purposes. The earliest results that appeared to discriminate between survivors and fatalities were the plasminogen levels at 12 to 24 hours. We conclude from these data that activation of coagulation, fibrinolytic, and complement systems occurs in all newborns with respiratory failure and is detectable in their laboratory measurements.

673 USE OF THE THROMBOELASTOGRAPH (TEG) IN DIAGNOSING DISSEMINATED INTRAVASCULAR COAGULATION (DIC) IN THE NEWBORN

The TEG is an automated and very sensitive technique for analyzing whole blood clotting time, requiring only 50 lambda whole blood. Its use in the newborn period has not been previously examined. We utilized thromboelastographic tracings in conjunction with standard coagulation studies to make the diagnosis of DIC in 6 of 13 critically ill newborns with severe birth asphyxia or respiratory failure from hyaline membrane disease. 7 healthy newborns served as a control population for normal values. Samples were drawn at 12 and 24 hrs of age in the control group and every 12 hrs for at least 72 hrs and up to 120 hrs in the study group. The control group showed a generally hypercoagulable state on samples drawn at 12 hrs of age as manifest by low R values and high MA and angle values. By 24 hrs of age the TEG conformed more to the normal adult curve. These patterns persisted after priming with Celite. The trend of the TEG in the study group was for the R values to increase, the MA and angle to decrease with time and the blood to become more hypocoagulable. The trend was accentuated in patients with DIC, progressing to a flat line in some patients. TEG patterns correlated well with elevations of fibrin split products and decreasing or low fibrinogen levels and platelet counts. This test is a technically simple, inexpensive and very rapid technique for diagnosing hyper- and hypo-coagulable states of blood clotting in the newborn.