[A computerized system for regional management of incidents is now tested. A complement to the Lex Maria system, indicates unobserved risks].
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Humans↗
Biomedical subjects
B Ekström-Jodal
Publications and source records attributed to B Ekström-Jodal.
[High-frequency oscillatory ventilation. A successful ventilatory techniques used in pediatric surgery].
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Child↗
[Investigate child health services!].
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Child↗
Effects of propranolol pretreatment on cerebral blood flow, oxygen uptake and catecholamines during metabolic acidosis following E. coli endotoxin in dogs.
After an intravenous injection of E. coli endotoxin in dogs a decrease in cerebral blood flow (CBF) and an increase in cerebral metabolic rate of oxygen (CMRo2) have been shown to occur. In metabolic acidosis following endotoxin CMRo2 increased with decreasing pH. A possible explanation for the increased CMRo2 after endotoxin and metabolic acidosis seems to be a damage of the blood-brain barrier (BBB) by endotoxin. This gives possibilities for a leakage of hydrogen ions and circulating monoamines from the blood to the brain, thus affecting the cerebral blood flow and metabolism. The effects of an E. coli endotoxin injection on CBF and CMRo2 during metabolic acidosis and beta-adrenoceptor blockade were studied in eight anaesthetized dogs. All the dogs were pretreated with propranolol (PPL), per os 12.5 mg.kg-1 twice a day for one week. Metabolic acidosis (pH 7.01-7.30) was achieved by an intravenous infusion of hydrochloric acid. Endotoxin E. coli lipopolysaccharide O 111:B 4 was given as an intravenous injection of 1 mg.kg-1 bodyweight over a 5 min period. Another five animals, published earlier, with the same experimental protocol but without PPL, constituted a control group. After endotoxin no increase in CMRo2 or CBF was observed with increasing acidosis in the PPL-group. In the control group, after endotoxin, both CBF and CMRo2 increased with decreasing pH. This resulted in a significant difference in both CBF and CMRo2 between the groups in the pH range 7.01-7.15. The present results indicate that the increase in CMRo2 and CBF with metabolic acidodis in endotoxinaemia is mediated via beta-adrenoceptors.
Acidosis↗
Effects of metabolic pH-alterations on cerebral blood flow and oxygen uptake following E. coli endotoxin in dogs.
The aim of the present study was to investigate if metabolic pH-alterations have an influence on cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) after an injection of E. coli endotoxin. Following endotoxin in dogs with normal pH a decreased CBF and an increased CMRO2 have earlier been found. Thirteen anaesthetized dogs were subjected to metabolic pH-variations in blood by infusion of hydrochloric acid or sodium bicarbonate. Ten dogs received E. coli endotoxin in a dose of 1 mg.kg-1 bodyweight. CBF, CMRO2 and noradrenaline and adrenaline concentrations in blood and cerebrospinal fluid were measured repeatedly during normoxia and normocarbia. Measurements before endotoxin served as controls, together with three additional animals, where endotoxin was never given. In control measurements pH showed no influence on the variables studied. After endotoxin CBF, CMRO2 and noradrenaline in cerebrospinal fluid increased with decreasing arterial blood pH. The influence exerted by metabolic pH alterations in blood after endotoxin may be explained by hydrogen ions and monoamines passing over a blood-brain barrier (BBB), damaged by endotoxin, into the brain tissue causing vasodilation and neuronal activation.
Acidosis↗
Cerebral function monitoring: a method of predicting outcome in term neonates after severe perinatal asphyxia.
The cerebral function monitor (CFM), a simplified one-channel EEG monitor, was evaluated in predicting outcome after severe perinatal asphyxia in 38 term infants. Survivors were followed until 1.5-2.5 years of age. All those 17 infants who survived without major neurological handicap showed continuous activity on the CFM trace during the first and/or second day of life. Twenty of the 21 infants who either died or developed severe neurological damage had burst suppression or paroxysmal activity on the first or second day of life. Thus cerebral function monitoring can be a valuable tool in predicting prognosis for infants with severe perinatal asphyxia.
Asphyxia Neonatorum↗
Distribution of radioactive microspheres injected into the vertebral artery of the dog.
The aim of the present study was to evaluate the use of the vertebral artery for cerebral blood flow studies. In eight dogs a small catheter was introduced into an unligated a. vertebralis sin. Radioactive microspheres (141Cerium) were injected and detected with a gamma camera. The microspheres were distributed to all parts of the brain. The concentrations were highest in the cerebellum, pons and medulla oblongata, while the total activity was greatest in the cerebrum because of its higher weight. The activity in the extracerebral tissues in the head was found to be less than 5% of the brain activity.
Animals↗
Effects of nitrous oxide/oxygen inhalation on the maternal circulation during vaginal delivery.
The hemodynamic changes occurring during the first stage of labor were studied in 24 healthy pregnant women during inhalation of different nitrous oxide/oxygen (N2O/O2) gas mixtures (intermittent 70/30, 40/60, 0/100 and continuous 40/60). Cardiac output increased (P less than 0.01) from 6.6 +/- 0.2 l/min between uterine contractions to 8.5 +/- 0.3 l/min during contractions. Heart rate, stroke volume, systolic, diastolic and mean arterial pressures were increased (P less than 0.01) and total peripheral vascular resistance was reduced (P less than 0.01) during contractions compared to measurements performed between contractions. The maternal circulation was influenced by the use of N2O/O2. During intermittent inhalation, higher concentrations of N2O were associated with a decrease (P less than 0.01) in heart rate, cardiac output and arterial pressure as well as an increase (P less than 0.01) in stroke volume. The degree of pain relief also increased (P less than 0.01) with increasing concentrations of inhaled nitrous oxide. The circulatory influence of intermittent inhalation given during uterine contractions was also apparent during the interval between contractions when N2O/O2 was not administered. The most obvious effects on both circulation and pain were demonstrated during continuous inhalation of N2O/O2. There was a close association between analgetic and cardiovascular effects indicating that the latter, at least partly, were due to pain relief. However, it was not possible to exclude or confirm possible direct pharmacological effects of N2O/O2 on maternal circulation.
Adult↗
Prevention of endotoxin-induced increase of cerebral oxygen consumption in dogs by propranolol pretreatment.
Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were studied in experimental endotoxic shock in dogs. Eight animals were pretreated with a beta-adrenoceptor blocking agent, propranolol (PPL), per os 12 mg/kg once a day for 7 days. Ten animals served as controls. After an intravenous injection of endotoxin, 1 mg/kg, CBF decreased in both groups, with no significant differences between the groups. CMRO2 increased in the control animals by about 18% from the baseline value both 1 and 2 h after the injection of endotoxin. CMRO2 in the PPL-pretreated animals was unchanged after endotoxin. The CMRO2-reactions to endotoxin in control and PPL animals were significantly different after both 1 and 2 h (P less than 0.05). The present results indicate that the increase in CMRO2 following intravenous endotoxin is mediated via beta-adrenoceptors.
Animals↗
Lung volume, gas mixing, and mechanics of breathing in mechanically ventilated very low birth weight infants with idiopathic respiratory distress syndrome.
We assessed pulmonary function in 14 mechanically ventilated newborn very low birth weight infants with idiopathic respiratory distress syndrome by means of a face-out, volume displacement body plethysmograph and nitrogen washout analyses. Specially designed computer programs were used for calculations of lung volumes, ventilation, gas mixing efficiency, and mechanical parameters. In addition to very low compliance and moderately elevated resistance of the respiratory system, there were considerably impaired gas mixing efficiency and low functional residual capacity (FRC). No correlations between positive end-expiratory pressure and mean airway pressure versus compliance, resistance, or FRC could be found. Neither could correlations be found between FRC and compliance or FRC and the calculated right to left shunt.
Female↗
A plethysmographic method for assessment of lung function in mechanically ventilated very low birth weight infants.
We have developed and tested a plethysmographic method for assessment of lung function in mechanically ventilated very low birth weight infants during intensive care. Information about the mechanics of the respiratory system is obtained from the respiratory flow as measured by volume displacement plethysmography and from airway pressure measured in the artificial airway. Data on lung volumes, ventilation, and distribution of ventilation is obtained simultaneously by combining the respiratory flow measurements with nitrogen concentration analyses of the respiratory gas. No significant differences were found when the estimations of mechanical parameters and FRC were compared with reference methods and when determinations of the same parameters were repeated in the same subjects. The plethysmograph was shown to be safe and convenient to use, even in studies lasting several hours.
Evaluation Studies as Topic↗
Influence of fluid regimens on perioperative blood-glucose concentrations in neonates.
Blood concentrations of glucose were measured during surgery and during the first 8 h after operation in 30 neonates undergoing major surgery during the first week of life. Fifteen of the neonates were given Ringer-acetate as the only crystalloid peroperative fluid; to the other 15, 10% glucose i.v. was administered during surgery. In the Ringer-acetate group, mean (SD) blood concentration of glucose increased from 3.1 (2.0) to 4.3 (2.4) mmol litre-1 during surgery. The corresponding increase in the glucose-supplemented group was 3.4 (1.5) to 6.3 (2.2) mmol litre-1. In the Ringer-acetate group, peroperative blood concentrations of glucose were found to be low if a preoperative glucose infusion was interrupted at the start of anaesthesia. Hypoglycaemia occurred in both groups, but more often in the group given Ringer-acetate only (3/15 vs 1/15). Hypoglycaemia was found only in neonates less than 48 h of age and during the first 1 h of anaesthesia only. Monitoring of blood concentrations of glucose and adjustment of the glucose infusion appears to be desirable during and after surgery in neonates.
Blood Glucose↗
Radial arterial catheters in children and neonates: a prospective study.
Over a 3-yr period (1982 to 1984), 533 arterial catheters were inserted in 476 patients admitted to the pediatric ICU or the operating room. Radial arterial catheterization with small-bore, 0.8-mm, 22-ga Teflon cannulas was the most common method (376 of 533 cannulations), and 296 of these catheters were inserted in patients less than 1 yr of age. All catheters were flushed intermittently with heparin (12.5 U/ml) in isotonic saline. The mean catheter duration was 2.6 days, and only minor complications were noted. The main reason for catheter removal was malfunction of the arterial line. There was no difference in duration or complication rate between catheters inserted percutaneously or by cutdown. Over a 6-month period (1985 to 1986), 42 0.8-mm, 22-ga radial arterial catheters were inserted in 39 patients less than 1 yr of age; all catheters were maintained by a continuous flushing system using heparin (5 U/ml) in isotonic saline. The mean duration was 6.3 days. No complications were noted, and the proportion of catheter malfunction decreased. This study confirms the safety of radial arterial catheterization in children and neonates. The continuous flushing system considerably improved catheter patency compared to a method using intermittent flushing.
Adolescent↗
Effects of rectal thiopentone and methohexitone on carbon dioxide tension in infant anaesthesia with spontaneous ventilation.
The influence of rectal administration of barbiturates on PCO2 during mask anaesthesia with spontaneous ventilation was studied in 72 infants. The age of the patients ranged between 6 and 24 months and they were all subjected to minor paediatric surgery. The patients were divided into four equally large groups: a control group receiving no premedication, a group receiving rectal thiopentone 30 mg X kg-1 and two groups receiving methohexitone either 20 or 30 mg X kg-1. In all patients PCO2 was measured in an arterialized capillary blood sample obtained during stable anaesthesia with oxygen, nitrous oxide and halothane before and after surgery. After rectal induction with barbiturates, the mean PCO2 was significantly higher in the different barbiturate groups than in the control group (P less than 0.05). The mean PCO2 value +/- s.d. in kPa for the control group was 5.6 +/- 0.7, for the group receiving thiopentone 30 mg X kg-1 6.5 +/- 1.6, for the groups receiving methohexitone 20 or 30 mg X kg-1 6.1 +/- 1.2 and 6.3 +/- 1.1, respectively. It is concluded that the combination of rectal induction with barbiturates and mask anaesthesia with oxygen, nitrous oxide and halothane carries an increased risk of hypoventilation in infants under 2 years of age.
Administration, Rectal↗
Carbon dioxide tensions in infants during mask anaesthesia with spontaneous ventilation.
Carbon dioxide tensions (PCO2) in arterialized capillary blood samples were measured in 39 infants anaesthetized for minor paediatric surgery. Anaesthesia was induced and maintained with oxygen, nitrous oxide and halothane, using a Mapleson-D system with spontaneous ventilation and a Rendell-Baker face mask. The duration of anaesthesia was between 15 and 95 min. Two capillary blood samples were obtained during stable anaesthesia before and after surgery. The PCO2 values varied between 3.7 and 8.0 kPa. The highest values were found in infants aged 15-30 days, 6.6 +/- 0.7 kPa (mean +/- s.d.), compared to 5.9 +/- 0.7 in infants aged 31-60 days, 5.6 +/- 0.8 in infants aged 61-180 days and 5.5 +/- 0.7 in infants aged 181-300 days. Comparison between measurements before and after surgery did not in any group indicate a progressive hypoventilation or a correlation between the length of the anaesthesia and the PCO2. It is concluded that anaesthesia with oxygen, nitrous oxide and halothane with spontaneous mask ventilation is a satisfactory method for minor procedures in infants over 1 month of age, while in younger infants controlled ventilation with intubation may be a safer choice of method.
Anesthesia, Inhalation↗
Prediction of symptomatic patent ductus arteriosus in preterm infants using Doppler and M-mode echocardiography.
To investigate whether the development of symptomatic patent ductus arteriosus could be predicted, 26 preterm infants dependent on mechanical ventilation were examined daily with Doppler and M-mode echocardiography until 3 days after birth. The presence or absence of a hemodynamically significant ductus shunt, as judged from echocardiographic criteria, was tested for predictive power in terms of sensitivity, specificity and total error rate. Out of the 26 infants 13 developed symptomatic patent ductus arteriosus at a median age of 5 days (range 2-8). These 13 infants developed echocardiographic evidence of a large shunt at a median age of 2 days (range 1-3). The sensitivity of prediction was 18, 46 and 100% at 1, 2 and 3 days after birth. The specificity was 80, 92 and 85% and the total error rate was 52, 32 and 8%. Thus, accurate prediction was possible 3 days after birth.
Ductus Arteriosus, Patent↗
Circulatory effects of carbon dioxide in experimental endotoxic shock.
In seven anaesthetized dogs the central circulatory effects of changes in Paco2 were studied before and after an intravenous injection of E. coli endotoxin 1.0 mg kg-1. The animals were on controlled ventilation with constant minute volumes, and Paco2 was changed by variations in the inspired gas mixture. Before endotoxin was given, cardiac output, mean aortic pressure, mean pulmonary artery pressure, total peripheral resistance and stroke volume were little affected by the changes in Paco2 from 3.9 +/- 0.4 to 7.2 +/- 0.4 kPa (mean +/- s.e.mean). Only heart rate decreased significantly (P less than 0.05). The intravenous endotoxin injection resulted in a decreased cardiac output (P less than 0.01), a decreased mean aortic pressure (P less than 0.01) and a decreased stroke volume (P less than 0.05). Mean pulmonary artery pressure, total peripheral resistance and heart rate showed only minor changes. In endotoxic shock an increase in Paco2 from 4.4 +/- 0.4 to 7.8 +/- 0.3 kPa (mean +/- s.e.mean) resulted in a significant increase in cardiac output (P less than 0.05), stroke volume (P less than 0.05) and mean pulmonary artery pressure (P less than 0.05), while the other parameters remained unchanged. It can be concluded that the carbon dioxide tension is of importance for the cardiac performance in experimental endotoxic stock in a manner not seen in control animals. The mechanisms behind these findings need further investigation.
Animals↗
Adenosine in the inhibition of diazepam sedation by aminophylline.
Aminophylline in a low dose has been shown to reverse diazepam sedation. The present investigation was performed as a double-blind study to compare the effects of aminophylline and enprofylline on deep diazepam sedation after surgery. Enprofylline is a xanthine derivative with anti-asthmatic effect but, in contrast to aminophylline, enprofylline has very weak adenosine antagonistic properties. A comparison should make it possible to evaluate if adenosine is involved in the observed effects. Twenty male patients undergoing transurethral surgery in spinal anaesthesia were given diazepam during surgery to maintain a state of deep sedation. Postoperatively aminophylline or enprofylline was given from coded ampoules in equipotent anti-asthmatic doses (4.5 or 1.5 mg/kg). The degree of sedation was assessed prior to and after the injections. A difference between the groups was obvious. Patients given aminophylline showed rapid reversal of sedation, persisting throughout the 2-h observation period. Following enprofylline, a markedly slower reversal of sedation was observed. It is likely that aminophylline antagonises diazepam sedation by blocking adenosine receptors. Some clinical implications are outlined.
Adenosine↗