morphine and Wounds-and-Injuries

To investigate the pulmonary effects of steroid treatment in neonates with meconium aspiration, 25 10- to 12-d-old piglets were studied for 6 h after an intratracheal bolus of human meconium. Dexamethasone (0.5 mg/kg) was given in two treatment schedules, either 1 h before (n = 6) or 1 h after meconium instillation (n = 8). Eight piglets served as controls. Three additional piglets were given dexamethasone without meconium instillation. Pulmonary hemodynamics and oxygenation were followed, and lung tissue samples investigated for signs of inflammation and ultrastructural injury, including apoptosis. Pulmonary artery pressure and vascular resistance increased after meconium instillation, but this rise was significantly prevented after prophylactic dexamethasone. This treatment also improved the acutely deteriorated oxygenation of the piglets after meconium insufflation. Prophylactic, but not early, dexamethasone treatment further protected the lungs from the ultrastructural changes caused by meconium instillation. Additionally, the increase of apoptotic epithelial cell deaths was significantly prevented by both dexamethasone treatments. These results show that prophylactic dexamethasone treatment significantly attenuates the early pulmonary hemodynamic deterioration and structural lung damage caused by meconium aspiration. Further studies on the apoptosis-inhibiting effect of dexamethasone administration in neonatal lungs exposed to heavy meconium are warranted.

Topics: Animals; Animals, Newborn; Apoptosis; Dexamethasone; Lung; Lung Injury; Meconium; Microscopy, Electron; Wounds and Injuries

Effective resuscitation of the newborn requires knowledge of the cause of depression. Four major causes are trauma, asphyxia, medication, and malformation. More than one of these may contribute to depression in a single infant. The first principles of resuscitation are to avoid cooling the infant and to establish an airway. Infants with an Apgar score of 3 to 4 at one minute usually need bag-and-mask ventilation, while those with scores of 0 to 2 require immediate ventilation, preferably by means of endotracheal intubation. Severely depressed infants may also require chemical resuscitation and closed cardiac massage. Fetal depression caused by narcotic analgesics given to the mother can be reversed with the use of naloxone hydrochloride (Narcan). Infants asphyxiated on the basis of malformations may benefit from expeditious diagnostic and therapeutic procedures performed in the delivery room.

Topics: Apnea; Asphyxia Neonatorum; Congenital Abnormalities; Delivery, Obstetric; Female; Fetus; Humans; Infant, Newborn; Infant, Newborn, Diseases; Intubation, Intratracheal; Maternal-Fetal Exchange; Meconium; Pregnancy; Resuscitation; Suction; Wounds and Injuries