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Biomedical subjects

J Thorburn

Publications and source records attributed to J Thorburn.

At least 91 records · Page 5Linked to original sources
PubMed1987

Background factors and management of ectopic pregnancy in Sweden. Changes over a decade.

Hospital records of all women operated on for ectopic pregnancy (EP) in four Swedish towns during 1970-72 and 1980-82 were elaborated. The gynecological and obstetrical background was noted and the clinical picture and management was recorded and analysed. The incidence of EP more than doubled between the two periods. There was no major change in classical background factors between the periods, but the proportion of IUCD users rose from 4 to 16 percent. The use of hCG assays, curettage and ultrasound in establishing the diagnosis increased markedly and the proportion of women with ruptured tubes and heavy intra-abdominal bleeding decreased. Moreover there was a clear tendency towards a more conservative surgical approach in the latter period.

Adult↗
PubMed1986

Background factors of ectopic pregnancy. I. Frequency distribution in a case-control study.

Two hundred and five patients with ectopic pregnancy in a well-defined Swedish population were interviewed with respect to prior disease and pregnancy histories as well as various constitutional and socioeconomic factors. The results were compared with those of two control groups, i.e. 110 early pregnant women intending to continue the gestation to term as well as 101 women seeking voluntary interruption of pregnancy. The results provide evidence that several may be involved in the etiology of ectopic pregnancy, including abdominal (or pelvic) surgery, previous ectopic pregnancy and pelvic inflammatory disease. Furthermore, a history of infertility is strongly correlated to ectopic pregnancy. On the other hand, there is no evidence that uncomplicated spontaneous or induced abortion, parity or marital status are important factors.

Abdomen↗
PubMed1986

Background factors of ectopic pregnancy. II. Risk estimation by means of a logistic model.

Based on the frequency distribution in a previous case-control study of ectopic pregnancy in Sweden, the prognostic value of a number of risk factors was analysed. A logistic procedure was applied in a stepwise manner, resulting in a risk-scoring model in which the probability of ectopic pregnancy can be determined on the basis of four background factors.

Abdomen↗
PubMed1985

Subarachnoid blockade and total hip replacement. Effect of ephedrine on intraoperative blood loss.

Thirty-eight patients undergoing total hip replacement under subarachnoid blockade were allocated randomly to one of two groups. Following institution of the blockade, patients in group A received ephedrine i.v. to maintain the systolic arterial pressure at, or above 100 mm Hg. Patients in group B were managed in an identical way, but did not receive ephedrine. Significant differences in arterial pressure (P less than 0.001), and heart rate (P less than 0.005), but no significant difference in blood loss was observed in the two groups. This was confirmed by similar blood transfusion requirements and postoperative haemoglobin concentrations. The relevance of the use of pressor agents in spinal anaesthesia is discussed.

Aged↗
PubMed1984

Choice of local anaesthetic drug for extradural caesarean section. Comparison of 0.5% and 0.75% bupivacaine and 1.5% etidocaine.

One hundred women undergoing elective lower uterine segment Caesarean section under extradural anaesthesia received either 0.5% or 0.75% plain bupivacaine or 1.5% etidocaine with adrenaline 1:200 000 by random allocation. The time taken to establish satisfactory blockade for surgery was significantly shorter in the etidocaine group compared with either of the bupivacaine groups (P less than 0.001). There were no significant differences in the durations of either analgesia or motor blockade in the three groups. The efficacy of the sensory blockade, measured by the incidence of discomfort during the surgical procedure and the requirements for supplementary analgesia or general anaesthesia, was greater in the bupivacaine groups compared with the etidocaine group. Measurement of plasma bupivacaine concentrations in 34 of the patients revealed significantly increased umbilical venous concentrations at the time of birth in those who received 0.75% bupivacaine (P less than 0.05). There was no advantage in the use of bupivacaine in concentrations exceeding 0.5%. Etidocaine 1.5% may be of some value in situations where minimal delay in establishing adequate extradural blockade for surgery is desirable, but in view of its comparatively poor analgesic effects, routine use is not recommended.

Acetanilides↗
PubMed1984

Bupivacaine toxicity in association with extradural analgesia for caesarean section.

Evidence of central nervous system toxicity was noted in two patients undergoing extradural analgesia for Caesarean section. There was no cardiovascular depression and both patients recovered rapidly. The patients had received total doses of bupivacaine plain solution of 357.5 mg and 356.25 mg, respectively and the relationship of these to the clinical signs of bupivacaine toxicity is discussed.

Adult↗
PubMed1981

Extradural analgesia: the influence of volume and concentration of bupivacaine on the mode of delivery, analgesic efficacy and motor block.

Five hundred and seventeen women in labour receiving extradural analgesia, using bupivacaine plain solution, were randomly allocated to one of three groups. Group A received 6-8ml of 0.5% solution, group B 10-14ml of 0.25% solution, and group C 6-8 ml of 0.25% solution. Spontaneous delivery occurred in 31.7% of patients in group A, 38.7% in group B and 53% in group C (P less than 0.001). The percentage of rotational forceps, ventouse and Caesarean section deliveries was similar in the three groups. Analgesia was most effective in group A, and at least in group C, both during labour and at delivery, although assessment by linear analogue score suggested that the differences between the three groups were slight. Motor block was most frequent and rapidly progressive in groups A, but was progressive in all groups, and after five or more top-up injections, was similar in the three groups. Difficulties with micturition following delivery were significantly more common in group A.

Adult↗
PubMed1980

Spinal and general anaesthesia in total hip replacement: frequency of deep vein thrombosis.

Subarachnoid block (SAB) or general anaesthesia (GA) was induced in 85 patients undergoing total hip replacement. The frequency of deep vein thrombosis (DVT), assessed by fibrinogen uptake studies and venography, was 29% in those patients receiving SAB and 54% in the GA group. Total blood loss (intra-operative and post-operative wound suction drainage) in SAB group was 66% and total transfusion volume 52% of that of GA group. No morbidity attributable to SAB or to the associated arterial hypotension was detected.

Aged↗
PubMed1980

Halothane improves the balance of oxygen supply to demand in acute experimental myocardial ischaemia.

Acute myocardial infarction was induced by ligation of the anterior descending branch of the left main coronary artery in greyhound dogs anaesthetized with pentobarbitone. Blood flow in the area of ischaemia was measured by xenon clearance and compared with flow in the circumflex artery measured with electromagnetic flow meters. Halothane 1% produced an approximate 40% reduction in flow to both ischaemic and normal areas in association with a 20% reduction in collateral perfusion pressure and a 40% reduction in mean arterial pressure. Comparison of the percentage change in the ratio of oxygen availability/consumption in response to halothane revealed a significant difference between the ischaemic and the normal areas. The former increased to 113 +/- 9.3% (mean +/- SEM) whilst the latter decreased to 91 +/- 5.02%. This suggests that, in the non-failing heart, halothane improves oxygenation in areas of acute myocardial ischaemia.

Acute Disease↗
PubMed1980

Epidural analgesia for elective Caesarean section. Technique and its assessment.

A technique is described of epidural anaesthesia for electric Caesarean section which has a 98% success rate, and an acceptably low incidence of intra-operative pain. The essentials of the technique are to produce and maintain complete sensory block from S5 to T6, employing a two-stage injection of bupivacaine 0.5% (mean dose 23 ml) and the use of gravity to ensure sacral block. Despite the use of preoperative fluid loading and avoidance of caval occlusion, transitory hypotension occurred in 16% of patients. Vomiting, which occurred in 18% of patients, is a minor but distressing complication.

Anesthesia, Epidural↗
PubMed1979

Effect of nitrous oxide on the cardiovascular system and coronary circulation of the dog.

A comparison was made in seven dogs anaesthetized with pentobarbitone of cardiovascular measurements during ventilation with 65-70% nitrous oxide in oxygen and ventilation with 65-70% nitrogen in oxygen. The substitution of nitrous oxide for nitrogen was found to be associated, after 15 min, with a significant decrease in cardiac output and significant increases in right atrial and left ventricular end-diastolic pressure and systemic vascular resistance. There was no significant change in mean coronary artery flow, coronary vascular resistance or myocardial oxygen consumption.

Animals↗
PubMed1979

Canine coronary blood flow responses to hypoxaemia: the influence of halothane.

Electromagnetic flow meters were used to measure blood flow in the coronary and pulmonary arteries of six anaesthetized dogs following thoracotomy. Halothane 1% (v/v) caused a reduction in arterial pressure, coronary artery flow, cardiac output and myocardial and total body oxygen consumption and an increase in coronary vascular resistance. Hypoxaemia caused large increases in coronary artery flow during both cardiac systole and diastole, but not until PaO2 was less than 5.3 kPa. This response was not influenced by the presence of halothane. Although myocardial oxygen availability and consumption were maintained during hypoxaemia, total body oxygen availability and consumption were markedly reduced.

Animals↗
PubMed1979

Effect of hypotension induced with sodium nitroprusside on canine coronary arterial flow.

In seven dogs anaesthetized with pentobarbitone, coronary and pulmonary artery blood flows were measured using electromagnetic flow meters. The infusion of a 0.01% solution of sodium nitroprusside caused an initial small increase in mean coronary artery flow which returned to control as the arterial pressure decreased. No changes were noted in cardiac output nor were further changes observed in coronary flow. Heart rate was increased consistently during the hypotension and left ventricular dp/dt max was reduced as were coronary and total peripheral resistances. There were no significant changes in myocardial or total body oxygen extraction or consumption.

Animals↗
PubMed1979

Response of mean and phasic coronary arterial blood flow to graded hypercapnia in dogs.

An electromagnetic flow meter was used to assess the changes in coronary blood flow in response to four levels of increased PaCO2 in six dogs. Mean, diastolic and systolic flow all increased during hypercapnia, the increase being maximal at mean PaCO2 11.3 KPa. Mean and diastolic coronary vascular resistances decreased progressively as PaCO2 increased, but systolic resistance, although decreasing with the lower levels of hypercapnia, returned to control at the greatest PaCO2. Although the oxygen available to the myocardium was increased markedly during hypercapnia, coronary sinus PO2 increased also, reflecting a reduction in myocardial oxygen extraction; thus myocardial oxygen consumption was unchanged. Cardiac output was increased significantly only at the greatest PaCO2. Total body oxygen handling was not altered significantly.

Animals↗