Biomedical subjects

L Lindgren

Publications and source records attributed to L Lindgren.

At least 163 records · Page 9Linked to original sources

PubMed1990

QT interval of the ECG, heart rate and arterial pressure using propofol, methohexital or midazolam for induction of anaesthesia.

The effects of propofol 2 mg/kg, methohexital 2 mg/kg or midazolam 0.3 mg/kg were studied on the QT interval of the ECG corrected by the heart rate (QTc), heart rate and arterial pressure during induction of anaesthesia in 87 ASA class I-(II)-patients. The patients were randomly allocated to one of the three anaesthetic groups. The incidence of the patients with a prolonged QTc interval (= more than 440 ms) ranged from 29 to 41% between the groups. In each group these patients were treated separately. After all anaesthetics, the QTc interval was significantly prolonged in the patients with a normal control QTc interval, whereas in the patients with a prolonged control QTc interval, it tended to be shortened both after propofol and methohexital and it was significantly shortened after midazolam. After injection of suxamethonium, no significant QTc interval changes occurred in the patients with a normal control QTc interval in either the propofol or the methohexital groups, whereas in the patients with a prolonged control QTc interval treated with propofol the QTc interval decreased significantly 60 s after suxamethonium when compared with the corresponding preceding values. The mean values in the propofol group in the patients with a normal control QTc interval were always below the upper limit of the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1989

Alfentanil obtunds the cardiovascular and sympathoadrenal responses to suxamethonium-facilitated laryngoscopy and intubation.

Alfentanil 75 micrograms kg-1 or saline (control group) was given 1 min before induction of anaesthesia in 20 healthy patients premedicated with diazepam 0.14 mg kg-1 and pethidine 1 mg kg-1. Anaesthesia was induced with a sleep dose of thiopentone preceded by glycopyrrolate. Suxamethonium 1 mg kg-1 was used to facilitate laryngoscopy (which lasted 10 s) and tracheal intubation. Arterial pressure, heart rate and noradrenaline concentration in mixed venous plasma increased significantly after suxamethonium, and increased further after laryngoscopy and intubation in the control group (n = 10). The QT interval of the ECG was prolonged after the administration of suxamethonium, and was prolonged further after laryngoscopy and intubation. All these changes were attenuated in patients pretreated with alfentanil (n = 10), but four patients had chest wall rigidity. Changes in the QT interval correlated directly with the changes in plasma noradrenaline concentration (r = 0.67). Plasma adrenaline concentrations decreased during induction of anaesthesia in both groups.

Adult↗

PubMed1989

Bradycardia in patients receiving atracurium or vecuronium in conditions of low vagal stimulation.

Four groups of 20 patients each received either vecuronium or atracurium together with either glycopyrronium or saline, and underwent anaesthesia free of vagolytic drugs, and surgery devoid of vagal activity. Determinations of plasma histamine concentrations were made to examine the possible correlation between these levels and changes in heart rate and blood pressure as well as a possible relationship with skin reactions after the administration of the relaxants. Patients who received vecuronium without the anticholinergic drug, glycopyrronium, showed a greater tendency towards bradycardia (though not statistically significant) than those given atracurium. More cutaneous reactions were observed with patients who received atracurium than in those with vecuronium, but there was no correlation with plasma histamine concentrations of either relaxant group. There was no correlation either between histamine concentrations and heart rate or blood pressure associated with atracurium. The incidence of bradycardia with either relaxant is low if the anaesthetic technique and the surgery are devoid of vagal activity.

Adult↗

PubMed1989

Transcriptional induction of Streptomyces cacaoi beta-lactamase by a beta-lactam compound.

The soil bacterium Streptomyces cacaoi produces an extracellular beta-lactamase. The beta-lactamase expression could be induced by the beta-lactam compound 6-amino penicillinoic acid (6-APA). In liquid cultures, a 50-fold increase in beta-lactamase expression was observed within the first three hours after addition of 6-APA. Using the cloned beta-lactamase gene as a probe, it was shown that this increase was mediated at the level of transcriptional initiation. The start point of the induced beta-lactamase transcript was determined, and the nucleotide sequence of the promoter region was analysed. No noticeable homology was found to control regions of inducible beta-lactamase genes of other bacteria. A striking feature was the presence of six direct repeats (ten base pairs each) upstream of the promoter region. Thus, an example of an inducible regulatory gene system in this Gram-positive microorganism is presented. Also, the primary structure of the beta-lactamase was deduced, showing a high degree of homology with class A beta-lactamases.

Amino Acid Sequence↗

PubMed1989

Treatment of post-thoracotomy pain with intermittent instillations of intrapleural bupivacaine.

The effect of intrapleural bupivacaine in the treatment of post-thoracotomy pain was evaluated. Bupivacaine, 0.5% 20 ml, with adrenaline (5 micrograms/ml) was given through an indwelling intrapleural catheter, at 4-h intervals four times daily for 2 days. No pleural suction was applied during and 10 min after each injection. A control group received intramuscular oxycodone on request. A visual analogue scale (VAS), a pain questionnaire (PQ) and registration of the need for supplementary analgesics were used for the assessment of postoperative analgesia. Blood-gas analyses showed elevated PaCO2 values in both groups on the day of operation and on the first postoperative day, without differences between the groups. Plasma concentrations of bupivacaine did not reach toxic values, and no symptoms of central nervous toxicity or any other untoward reactions were found during the study period. Clinically, there was some pain relief after the intrapleural bupivacaine. The VAS and PQ scores 30 min after bupivacaine instillations diminished to an extent similar to that after oxycodone treatment. The need for analgesics during the day of operation was less in the bupivacaine group than in the control group (P less than 0.001). The number of oxycodone supplementation doses during 48 h postoperatively was, however, not smaller in the bupivacaine group than in the control group.

Bupivacaine↗

PubMed1988

Increase in intragastric pressure during suxamethonium-induced muscle fasciculations in children: inhibition by alfentanil.

Changes in intragastric pressure after the administration of suxamethonium 1.5 mg kg-1 i.v. were studied in 32 children (mean age 6.9 yr) pretreated with either physiological saline or alfentanil 50 micrograms kg-1. Anaesthesia was induced with thiopentone 5 mg kg-1. The incidence and intensity of muscle fasciculations caused by suxamethonium were significantly greater in the control than in the alfentanil group. The intragastric pressure during muscle fasciculations was significantly higher in the control group (16 +/- 0.7 (SEM) cm H2O) than in the alfentanil group (7.7 +/- 1.5 (SEM) cm H2O). The increase in intragastric pressure was directly related to the intensity of muscle fasciculations (regression line: y = 0.5 + 4.78x with r of 0.78). It is concluded that intragastric pressure increases significantly during muscle fasciculations caused by suxamethonium in healthy children. Alfentanil 50 micrograms kg-1 effectively inhibits the incidence and intensity of suxamethonium-induced muscle fasciculations; moreover, intragastric pressure remains at its control value.

Alfentanil↗

PubMed1988

Comparison of chloral hydrate and midazolam by mouth as premedicants in children undergoing otolaryngological surgery.

Chloral hydrate 25, 50 or 75 mg kg-1 or midazolam 0.4, 0.5 or 0.6 mg kg-1, all given by mouth in combination with atropine 0.03 mg kg-1, were compared as premedication in 248 children in a randomized, double-blind study. Chloral hydrate was significantly less palatable than midazolam. The anxiolytic effect of chloral hydrate 75 mg kg-1 was "good" in children younger than 5 yr, whereas the other doses of chloral hydrate, and all doses of midazolam, provided only "fair" anxiolysis in this age group. All doses of both premedicants provided good anxiolysis in the older children. A satisfactory antisialogogue effect was seen in 83-90% of each group. About 20 min after extubation, restlessness was observed in 15-25% of the younger children premedicated with chloral hydrate 25 mg kg-1 or with midazolam 0.4 or 0.6 mg kg-1. The mean total recovery score (0-10) based on activity, ventilation, heart rate, conscious level and colour ranged between 5.8 and 6.8 at 10 min and between 9 and 9.5 at 70 min after extubation in all groups. Midazolam 0.5 mg kg-1 is recommended for children less than 5 yr of age and midazolam 0.4-0.5 mg kg-1 for older ones. Chloral hydrate 75 mg kg-1 provided good anxiolysis in both age groups; however, it was less palatable than the midazolam.

Administration, Oral↗

PubMed1988

Optimal time interval between pretreatment with alcuronium and suxamethonium during anaesthetic induction.

Alcuronium 0.03 mg/kg was studied in a double-blind randomized fashion as a pretreatment before suxamethonium using different time intervals between the administration of the drugs in 78 patients (ASA I-II) undergoing otolaryngological surgery. Alcuronium was given 1, 2 or 3 min before suxamethonium 1.5 mg/kg. The control group received saline as a pretreatment and suxamethonium 1 mg/kg. Anaesthesia was induced with thiopental 5.5 mg/kg over 60 s. Muscle fasciculations, intubating conditions, cardiovascular responses to endotracheal intubation and duration of neuromuscular block were assessed. Muscle fasciculations were statistically and similarly inhibited (P less than 0.01) at all time intervals between alcuronium and suxamethonium. Intubating conditions were worse (P less than 0.05) in the 3-min group than in the other groups. Cardiovascular responses to endotracheal intubation were similar in all groups. The neuromuscular block after suxamethonium was significantly shorter (P less than 0.05) in the 2- and 3-min groups than in the other groups. In conclusion, from the clinical point of view the 1-min time interval between alcuronium and suxamethonium is optimal since muscle fasciculations are inhibited and intubating conditions are satisfactory.

Adult↗

PubMed1988

QT interval of the ECG, heart rate and arterial pressure using five non-depolarizing muscle relaxants for intubation.

The QT interval, heart rate and arterial pressure were measured during anaesthetic induction in 186 patients without cardiovascular diseases or any preoperative drugs. The study was randomized and double-blind. The patients were premedicated with either pethidine 1 mg/kg + atropine 0.01 mg/kg or with only pethidine 1 mg/kg i.m. Anaesthesia was induced with thiopental. After both types of premedication, either d-tubocurarine 0.5 mg/kg, alcuronium 0.3 mg/kg, pancuronium 0.1 mg/kg, vecuronium 0.1 mg/kg or atracurium 0.5 mg/kg was injected after thiopental. Laryngoscopy was performed 4 min after the relaxant. The control values of the QT intervals (mean value 433 ms, range of the mean values 422-453 ms), were comparable. After thiopental, the mean values in the groups were no longer in the normal range (less than 440 ms). After atropine, the values at 3 min were statistically significantly prolonged in the pancuronium, atracurium and alcuronium groups, but not in the other groups, when compared with the values after thiopental. In the absence of atropine, no statistically significant prolongation of the QT interval occurred. After intubation in the absence of atropine, the values were statistically significantly prolonged in the alcuronium, pancuronium, vecuronium and atracurium groups and in the presence of atropine in the atracurium group when compared with the preceding values. The QT intervals were prolonged only in relation to the increased heart rate. At 6.5 min, the values in all groups were decreased to about the same level as before intubation. The mean control values of the heart rate were between 80 and 90 b.p.m. in the atropine-treated groups and between 70 and 80 b.p.m. in the other groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1987

Retro-Gasserian glycerol injection in the treatment of chronic cluster headache.

Seven therapy-resistant patients with cluster headache (six of whom were chronic) were treated by percutaneous retro-Gasserian glycerol injections under general anesthesia. In four of the patients immediate and complete relief of attacks was obtained. There was a close correlation between pain relief and the degree of ophthalmic sensory loss. Quantitative estimation of thresholds for thermal perception and pain showed a good correlation to clinically evaluated sensory loss. As the analgesia waned, headaches returned, and the glycerol injections had to be repeated. Two patients were still considerably improved after 5 1/2 and nearly 3 years, respectively. In the other patients the results were less satisfactory at long-term follow-up study. Pure glycerol is highly hypertonic, and the damage of the trigeminal nerve root may be due to this property.

Adult↗

PubMed1987

Labetalol as a hypotensive agent for middle ear microsurgery.

Labetalol, an alpha- and beta-adrenergic receptor-blocking agent, was studied as a hypotensive agent during halothane (mostly 0.5 vol.%)-N2O-fentanyl-d-tubocurarine anaesthesia with a head-up tilt of 5 degrees in 41 patients undergoing middle ear microsurgery. After the mean initial dose of 0.3 mg/kg, the mean need for labetalol ranged from 0.05 to 0.07 mg/kg at 30 +/- 5-min intervals. The mean duration of the hypotensive period was 102 min. During the hypotension, the average mean arterial pressure ranged from 59 to 62 mmHg (7.9-8.3 kPa) and the mean heart rate from 61 to 66 b.p.m. After labetalol the maximum cardiac output decrease was 7%. Before labetalol the mean PaO2 value was 158 mmHg (21.1 kPa) and during hypotension it ranged from 145 to 149 mmHg (19.3-19.9 kPa) when FiO2 was 40%. The only peroperative side effects were ECG changes (middle junctional rhythm and sinus bradycardia) which occurred in 10% of the patients. The mean value for the degree of haemostasis rated by the otologist on a visual analogue scale between poor (0 mm) and excellent (100 mm) was 91 mm. The patients were able to open their eyes and to give their names 8-9 min after the end of anaesthesia. After extubation the patients were normotensive and there were no clinically significant changes in the cardiovascular parameters during the 4-h recovery room period. Acid-base status showed slight metabolic acidosis. The most common postoperative side effects were nausea only and nausea + vomiting, which occurred in 39% and 20% of the patients, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Acid-Base Equilibrium↗

PubMed1987

Protection by fentanyl against cardiac dysrhythmias during induction of anaesthesia.

The effect of fentanyl on electrocardiographic changes during anaesthetic induction was studied in 113 adults and 77 children. The adults were pretreated with fentanyl 1, 2 or 3 micrograms kg-1 and the children received fentanyl 1 or 2 micrograms kg-1 as pretreatment. The control groups received no pretreatment. Two minutes after the pretreatment, thiopentone 5 mg kg-1 was injected followed by succinylcholine 1.5 mg kg-1 before laryngoscopy and intubation. In control adults, ventricular ectopic beats (VEB) occurred in 26% of the patients whereas fentanyl in all doses totally prevented them. In children, the incidence of VEB was 22% in the control group whereas both doses of fentanyl prevented the occurrence of VEB. In any doses, fentanyl did not prevent the prolongation of QT interval after succinylcholine.

Adult↗

PubMed1986

Enflurane inhibits muscle fasciculations caused by suxamethonium in children.

Eighty-three children with a mean age of 2.7 years were anaesthetized with either thiopental 5 mg/kg followed by suxamethonium 1.5 mg/kg i.v. or with enflurane 5 vol% in 70% nitrous oxide in oxygen via a face mask. In the enflurane group, venepuncture was performed when the children were unconscious, 1.8 +/- 0.05 (s.e.) min after the start of anaesthesia. After enflurane, suxamethonium 1, 1.5 or 2 mg/kg was administered i.v. for endotracheal intubation. The incidence and duration of muscle fasciculations after suxamethonium were significantly lower (P less than 0.01) in the enflurane groups than in the thiopental group. The fasciculation index was significantly lower (P less than 0.01) in the enflurane groups than in the thiopental group. In the enflurane groups, intubating conditions were better (P less than 0.05) in the children treated with suxamethonium 2 mg/kg than in those treated with suxamethonium 1 mg/kg.

Child↗

PubMed1985

Cardiovascular responses to tracheal intubation in small children. Effects of the induction of anaesthesia with halothane.

Cardiovascular changes in 27 children (mean age 1.5 yr) were studied during the induction of anaesthesia with 2.5% halothane and 70% nitrous oxide in oxygen. The eyelash reflex disappeared in a mean of 62 +/- 3.6 (SEM)s and tracheal intubation could be performed 4.9 +/- 0.2 min after the start of halothane anaesthesia. Intubating conditions were satisfactory in 85% of the children. Systolic arterial pressure increased by 10.8 +/- 1.9 mm Hg and diastolic pressures by 6.0 +/- 1.4 (SEM) mm Hg after intubation of the trachea. Heart rate decreased significantly after induction. No cardiac arrhythmias were noted. There were no significant changes in Q-T interval after induction, after intubation or during the later course of the anaesthetic.

Anesthesia, Inhalation↗

PubMed1985

Comparison of paracetamol and aminophenazone plus diazepam suppositories for anxiety and pain relief after tonsillectomy in children.

The anxiety and pain-relieving effect of paracetamol 10 mg/kg or a combination of aminophenazone 4 mg/kg and diazepam 0.2 mg/kg suppositories was studied in 82 children after tonsillectomy in a double-blind study. Both suppositories were studied after halothane or enflurane anaesthesia. At 30 min after administration of coded suppositories, 88-90% of the children in various groups needed extra analgesics, and received pethidine 0.5 mg/kg i.v. Thereafter, the anxiety and pain relief was satisfactory in all groups. There was no significant difference between the effects caused by the drugs. No bleeding occurred from the operation site in any of the study groups. The results suggest that both paracetamol and a combination of aminophenazone and diazepam in the doses used here were weak analgesics for throat pain after tonsillectomy in children during the early postoperative period.

Acetaminophen↗

PubMed1985

Hypoxic pulmonary vasoconstriction in isolated rat lungs perfused with perfluorocarbon emulsion.

Eight rat lungs were perfused in an in vitro circuit with a blood-PS solution and then with a perfluorocarbon emulsion (perfluorotributylamine, FC-43). With perfusion flow constant, the hypoxic pulmonary vasoconstrictor (HPV) response was measured as changes in pulmonary artery pressure when F1,O2 was changed to 0.1, 0.06, 0.04, 0.03, 0.02 and zero with FI,CO2 of 0.05. The hypoxic response to an FI,O2 of 0.03, with the blood-PSS perfusate, was an increase from baseline pressure of 93.5 +/- 18% and, with the perfluorocarbon perfusate was 67.5 +/- 18%; these values were not significantly different (P greater than 0.2). A stimulus-response relationship was obtained with the FC-43 perfusate by plotting the response as a percentage of the maximum response (R%max) against the logarithm of the alveolar oxygen tension. The equation for the linear portion of the response was R%max = 257.9-140.2 X log (10) PA,O2 and r = 0.78. The PA,O2 corresponding to half of the maximum response (ED50) was 30.4 mmHg. The present study demonstrated that HPV is maintained in isolated rat lungs perfused with an FC-43 emulsion. The stimulus-response relationship as well as the ED50 with the FC-43 is similar to earlier results with blood perfusate. Lung oedema was not found after perfusion with the FC-43 emulsion.

Animals↗

PubMed1985

Thymidine kinase in brain-tumor cysts.

A recently developed method for deoxythymidine kinase (TK) determination was applied to brain-tumor cyst fluid and fluid from a non-neoplastic intracerebral cyst. The fluid from all tumors tested positive for TK whereas the non-neoplastic cyst lacked TK. Cyst fluid was also analyzed for TK before and after intracystic instillation of BCNU. It is suggested that TK activity in the fluid in cystic brain lesions could prove useful in deciding whether an intracerebral lesion is neoplastic. Also, TK activity can be used to evaluate the effect of topical therapy.

Brain Neoplasms↗

PubMed1984

Effects of halothane, enflurane, and isoflurane on hypoxic pulmonary vasoconstriction in rat lungs in vitro.

Rat lungs were ventilated and perfused at a constant rate in vitro. The maximal hypoxic pulmonary vasoconstrictor (HPV) response was recorded by measuring the pulmonary artery pressure change when the inspired oxygen concentration was changed from 21% to 3% (with 5.5% carbon dioxide) in the absence of anesthetic vapor. In different experimental groups, the effects of halothane, enflurane, and isoflurane on HPV were examined. In random order the anesthetics were added to the inspired gas in concentrations of 0.25, 0.5, 1, 1.5, and 2 or 2.5 MAC units. The HPV pressor response to 3% oxygen in the presence of anesthetic agent was expressed as a per cent of the pressure response observed in the absence of anesthetic (R%MAX). All three agents depressed HPV in a dose-related manner. The concentrations in MAC units at which 50% depression of HPV (ED50) occurred was 0.47, 0.60, and 0.56 for halothane, isoflurane, and enflurane, respectively, and neither the ED50 values nor the slopes of these dose response curves were significantly different. It was concluded that these halogenated general anesthetics inhibit HPV with essentially the same potency.

Animals↗