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Biomedical subjects

R Magno

Publications and source records attributed to R Magno.

17 recordsLinked to original sources
PubMed1981

Myocardial metabolism in relation to electrocardiographic changes and cardiac function during graded hypoxia in the fetal lamb.

Previous studies from this laboratory have demonstrated early and progressive alterations in the ST-T period of the fetal and neonatal electrocardiogram in relation to asphyxia. The aims of the present study were to investigate the metabolic background of these hypoxic ECG changes by means of serial myocardial biopsies in fetal lambs, relating these changes to the hypoxic depletion of glycogen, ATP and creatine phosphate stores in the heart and to the altered myocardial performance as measured by heart rate, mean arterial blood pressure, combined cardiac output and max. dP/dt. The experiments were performed on 21 fetal lambs, acutely exteriorized and subjected to graded hypoxia. During hypoxia there was a significant relationship between the degree of changes in the ST-T period according to a scoring system and the depletion of myocardial glycogen and ATP, a highly significant correlation between the rate of myocardial glycogenolysis and the rate of increase in T wave amplitude, and a parallelism between the amount of glycogen available and fetal cardiovascular function. The myocardium was capable of regenerating its glycogen stores under conditions of adequate oxygenation and in the absence of acidosis and hypoglycaemia.

Adenosine Triphosphate↗
PubMed1980

Anesthesia for cesarean section.--VI Late effects on the infant of enflurane anesthesia for cesarean section.

Enflurane anesthesia for cesarean section has given favourable results with regard to anesthetic effect and lack of depression of the neonate. Enflurane is metabolized to fluoride. High serum levels of inorganic fluoride are nephrotoxic. The nephrotoxic level is known for healthy adult kidneys but not for neonatal kidneys. In a study on enflurane anesthesia for cesarean section serum analyses revealed increased inorganic fluoride levels in the neonates. To exclude unwanted effects on the children, a follow-up study was undertaken 6-12 months after delivery. General development and renal function were studied. No abnormalities were found, indicating that enflurane anesthesia for cesarean section has no persistent unfavourable effects on the children.

Anesthesia, Inhalation↗
PubMed1980

Anesthesia for cesarean section--VII. Early effects on neonatal renal function of enflurane anesthesia for cesarean section.

Fourteen women undergoing elective cesarean section were anesthetized with enflurane for induction and maintenance of anesthesia. Blood enflurane and serum inorganic fluoride levels were studied in the mothers at delivery and in the neonates at delivery and in the early neonatal period. Also neonatal urinary excretion of inorganic fluoride was determined. Renal function of the neonates was tested with a sodium load at the age of 1 day. Enflurane showed the expected distribution between mothers and neonates. The enflurane level of the neonates declined rapidly after delivery. Serum inorganic fluoride level increased significantly in the mothers from start of anesthesia until delivery. The neonatal level was lower and did not reach the level of neonates in areas with a high natural fluoride content in drinking water. The level of inorganic fluoride in urine was higher than the corresponding serum level, indicating an inorganic fluoride concentrating effect of the neonatal kidney. The difference between urinary excretion and serum content of inorganic fluoride showed neonatal metabolism of enflurane. The urinary sodium excretion did not differ from that of infants delivered without halogenated inhalation agents given to the mothers.

Anesthesia, Inhalation↗
PubMed1979

Acid-base balance during laparoscopy. The effects of intraperitoneal insufflation of carbon dioxide and nitrous oxide on acid-base balance during controlled ventilation.

During laparoscopy the carbon dioxide used to achieve a pneumoperitoneum is absorbed from the peritoneal cavity into the blood. The object of the present study was to clarify certain aspects concerned with anesthetic and ventilatory techniques, mostly in connection with the comparison between the effects of insufflation of either carbon dioxide or nitrous oxide. Anesthesia included ventilation with a volume controlled ventilator in curarised patients. Respiratory volumes were calculated according to the patient's body area. The results show a sharp rise in PaCO2 and a fall in pH after intraperitoneal insufflation with carbon dioxide, while no changes were observed when nitrous oxide was used. The clinical consequences of these findings are discussed.

Acid-Base Equilibrium↗
PubMed1977

Ebstein's anomaly--anaesthetic problems. A case report.

A patient with Ebstein's anomaly undergoing anaesthesia for the operation of hysterectomy is reported. The considerations relating to the risk of an increased right-to-left intracardiac shunt are discussed. The patient was anaesthetized successfully with a combination of nitrous oxide, droperidol and fentanyl.

Adult↗
PubMed1976

Anesthesia for cesarean section III: effects of epidural analgesia on the respiratory adaptation of the newborn in elective cesarean section.

A rise in fetal Paco2 was observed after elective cesarean section in patients anesthetized both with a barbiturate and with nitrous oxide/oxygen. Epidural analgesia seemed to be a good alternative in order to attain better blood gas values in the newborn infant. Fourteen healthy mothers and their infants were studied in connection with elective cesarean section. Epidural analgesia with plain bupivacaine 0.75% was used. Doses varied between 90 and 120 mg. The time between the epidural injection and delivery was around 50 min. In six cases the fetal heart rate was registered continuously. Most of the mothers were sedated with diazepam intravenously or fully anesthetized, after delivery. The mothers were interviewed later. The respiratory adaptation of the infants was studied by blood gas and acid-base measurements in repeated arterial samples during the first 3 hours of life. A comparison was made with a group previously studied, where general anesthesia with a barbiturate, nitrous oxide/oxygen was the method used. The present material showed no differences concerning Pao2 and Paco2 but clearly indicated a tendency towards an earlier normalization of the initial metabolic acidosis. Mothers showed a respiratory alkalosis which was overcompensated by the metabolic component. Maternal blood pressure falls were observed in four cases, and fetal effects could be detected. Although epidural analgesia has a more favorable effect upon the newborn's metabolic component, both the compared methods allow good respiratory adaptation provided they are used correctly. Mothers can be given the opportunity to choose between being conscious or asleep when their child is delivered.

Adaptation, Physiological↗
PubMed1976

Anesthesia for cesarean section IV: placental transfer and neonatal elimination of bupivacaine following epidural analgesia for elective cesarean section.

Epidural analgesia with bupivacaine was used for elective cesarean section, and repeated maternal and neonatal blood samples were collected over 24 h for calculation of drug concentration. A gas-chromatogrphic micro-method was used for the analysis. The aim of this investigation was to evaluate the placental transfer and the elimination rate of the drug. No signs of systemic toxicity were observed in any mother or child, despite relatively high blood concentrations. The fetal-maternal ratio of concentrations at delivery was higher than in previous studies, most probably due to the protein-binding characteristics of bupivacaine and the dosage used. The biological half-life of the rapid phase of elimination (alpha-phase) in the newborn was shorter than in the mother (P less than 0.002), indicating a more rapid distribution process. The half-life of the slow phase of elimination (beta-phase) in the newborn was of the same magnitude as in the mother, indicating that neonatal elimination processes of bupivacaine may be well developed at birth.

Adult↗
PubMed1976

Anesthesia for cesarean section V: effects of enflurane anesthesia on the respiratory adaptation of the newborn in elective cesarean section.

The new anesthetic inhalation agent, enflurane, is supposed to allow rapid induction and recovery. Experinece with this agent in obstetrics is limited. Enflurane was therefore studied in 14 pregnant women undergoing elective cesarean section. Its effects upon the respiratory adaptation of the newborn infants were followed during the first 3 hours, as judged by oxygen tensions and acid-base balance measurements in serial neonatal arterial samples. Results were compared with those from a previously studied group of women anesthetized with a barbiturate and nitrous oxide-oxygen. There were no differences with respect to oxygen tension. Carbon dioxide values in the enflurane group were higher than those in the barbiturate group. In comparison with the barbiturate group the enflurane group of babies had lower BD values, which is a sign of a better metabolic state post-partum. Mothers anesthetized with enflurane were satisfied with the method, especially for the post-operative period.

Adaptation, Physiological↗
PubMed1975

Anesthesia for cesarean section II: effects of the induction-delivery interval on the respiratory adaptation of the newborn in elective cesarean section.

Ten healthy mothers and their infants were studied in connection with elective cesarean section. Anesthesia was induced with 250-300 mg hexobarbitone followed by 100 mg succinylcholine for endotracheal intubation. The surgeon started the operation when the eyelid reflex disappeared, and delivered the baby as quickly as possible. Mean induction-delivery (I-D) interval was 2 min 45 s. Anesthesia was then deepened with further barbiturate, diazepam and methoxyflurane, and alcuronium used as muscle relaxant. The respiratory adaptation of the infant was studied by blood gas and acid-base measurements in repeated arterial samples during the first three hours of life. The mothers were interviewed after 3-12 months. A comparison was made with another barbiturate group with a longer I-D interval (x = 9 min 10 s). The present material showed initially higher PaO2 lower PaCO2, higher pH and less base deficit (BD), which relfected the maternal state at delivery. After 10-30 min, the results approached equivalence, though the babies in the short I-D group showed a tendency toward normalization of metabolic acidosis earlier. At the interviews, two mothers complained of pain during skin incision, and two of nightmares. Anesthesia with barbiturate for cesarean section with the I-D intervals studied in both groups allowed good respiratory adaptation in the infants. There is, neverless, the need for an adequate period of time between induction and the start of the operation in order to minimize the risk for maternal awareness.

Adolescent↗