beta-endorphin and Infant--Newborn--Diseases

The efficacy and safety of morphine sulfate was evaluated in 20 neonates requiring surgery. Following surgery, each subject received an intravenous morphine loading dose (50 micrograms/kg) followed by a continuous infusion (15 micrograms/kg/hr) for a minimum of 24 hours. Heart rate, respiratory rate, and blood pressure were frequently monitored during therapy. Blood samples were obtained following surgery and during and after morphine therapy for analysis of serum morphine and beta-endorphin content. A 12-hour urine collection was obtained 12 hours following the start of the constant morphine infusion for analysis of morphine content. The mean (+/- SD) duration of morphine infusion was 34 +/- 15 hours and a steady-rate serum morphine concentration was 39 +/- 23 ng/ml. The respective serum morphine half-life, elimination rate, and volume of distribution were 6.6 +/- 2.9 hr, 0.126 +/- 0.056 hr-1, and 5.0 +/- 6.8 liters/kg. The mean percentage of unchanged morphine recovered in the urine was 39 +/- 19 of the dose administered over 12 hours. A significant reduction in serum beta-endorphin content was observed following the onset of morphine therapy. No adverse reports were noted that could be attributed to morphine therapy. Continuous morphine therapy appears to be effective in controlling neonatal postoperative pain, as suggested by subjective nursing observations and decreased serum beta-endorphin content.

Topics: Analgesia; beta-Endorphin; Half-Life; Humans; Infant, Newborn; Infant, Newborn, Diseases; Infusion Pumps; Infusions, Intravenous; Morphine; Pain, Postoperative

The effects of intrauterine stress and birth asphyxia on the plasma concentration of beta-endorphin (beta-E) in cord blood and in venous blood at the age of 2 h was investigated in newborn infants. Term infants with acute birth asphyxia (n = 11), infants born to mothers with preeclampsia (n = 15), and prematures with respiratory difficulties (n = 4) were entered into the study. Twenty control infants were studied; 12 were born after spontaneous delivery and eight after elective cesarean section. After normal spontaneous delivery, the plasma beta-E level decreased significantly, the median values being 17 pmol/liter at birth and 9.3 pmol/liter at the age of 2 h, whereas after elective cesarean section it remained unchanged (13 and 13 pmol/liter, respectively). In acute asphyxia the plasma beta-E level varied widely at birth, from 9.7 to 108 pmol/liter. At the age of 2 h, the beta-E level was high (26 to 83 pmol/liter) in those asphyctic infants who required prolonged mechanical ventilation, but it fell to the range of 1.6-13 pmol/liter when the infant recovered rapidly. The beta-E level was not increased in the preeclampsia group, not even in small for gestational age infants. In preterm newborn infants with respiratory difficulties, a significant postnatal rise of plasma beta-E level was found, the beta-E value varying from 7.3 to 16 pmol/liter at birth and from 61 to 168 pmol/liter at the age of 2 h. These results indicate that increased beta-E secretion is associated with respiratory difficulties in the newborn infant.

Topics: Apgar Score; Asphyxia; beta-Endorphin; Endorphins; Female; Fetal Blood; Gestational Age; Humans; Infant, Newborn; Infant, Newborn, Diseases; Placental Insufficiency; Pregnancy; Respiration Disorders

Topics: Apnea; beta-Endorphin; Endorphins; Humans; Infant, Newborn; Infant, Newborn, Diseases; Infant, Premature, Diseases