Biomedical subjects

L Saarnivaara

Publications and source records attributed to L Saarnivaara.

At least 19 recordsLinked to original sources

PubMed1995

Modification of the haemodynamic responses to induction of anaesthesia and tracheal intubation with alfentanil, esmolol and their combination.

The purpose of this double-blind randomized work was to study the effect of alfentanil and esmolol and their half-dose combination on the increases of heart rate and arterial pressure and on the prolongation of the QTc interval of the ECG occurring during anaesthetic induction. Sixty ASA class I-II patient with mean age ranging from 26 to 32 yr among the groups. Patients were allocated to one of four equal groups to receive saline, esmolol 2 mg.kg-1, alfentanil 0.03 mg.kg-1 and alfentanil 0.015 mg.kg-1+esmolol 1 mg.kg-1. Anaesthesia was induced with thiopentone. Succinylcholine was used to facilitate tracheal intubation. Haemodynamic variables were measured non-invasively and the QTc interval with the aid of a microcomputer. Comparisons between the groups were performed using two-way analysis of variance with repeated measures. Both alfentanil and alfentanil-esmolol prevented the increase of heart rate and arterial pressure caused by intubation whereas esmolol prevented only the increase of the heart rate. None of the treatments prevented prolongation of the QTc interval after intubation and only alfentanil prevented that after succinylcholine. The present results suggest that in the prevention of the haemodynamic responses to tracheal intubation, the half-dose combination of alfentanil and esmolol is as effective as alfentanil and superior to esmolol. The combination is preferable to relatively large doses of either drug in circumstances where side effects, such as respiratory depression due to alfentanil or bradycardia due to both drugs should be minimized.

Adrenergic beta-Antagonists↗

PubMed1995

Effect of transdermal hyoscine on nausea and vomiting after surgical correction of prominent ears under general anaesthesia.

In a double-blind, randomized study, we have compared the efficacy of transdermal hyoscine with placebo in the reduction of nausea and vomiting in 50 patients, ASA I-II, after surgical correction of prominent ears under general anaesthesia. In the placebo group, 28%, 4% and 48% of patients suffered nausea, retching and vomiting, respectively, during the first 24 h after anaesthesia. The corresponding values in the hyoscine group were 12%, 0% and 16% (P < 0.01). In the placebo group more patients (48%) needed droperidol as an antiemetic compared with the hyoscine group (16%; P < 0.05). There was significantly more sedation in the hyoscine group.

Administration, Cutaneous↗

PubMed1995

QT interval of the ECG, heart rate and arterial pressure during anaesthetic induction: comparative effects of alfentanil and esmolol.

In a double-blind study the effect of esmolol and alfentanil on the QT interval of the ECG corrected by the heart rate (QTc), heart rate and arterial pressure during anaesthetic induction was studied in 59 oxycodone- and atropine-premedicated ASA class I-(II) patients with a mean age of 26 yr (range 15-50 yr). The patients were randomly allocated to one of the four groups: saline, esmolol 2 mg.kg-1, esmolol 3 mg.kg-1 or alfentanil 0.03 mg.kg-1. Both doses of esmolol prevented the prolongation of the QTc interval after thiopental and suxamethonium, but not after laryngoscopy and intubation. Alfentanil prevented the prolongation of the QTc interval following thiopental, suxamethonium and laryngoscopy but not after intubation. Esmolol did not prevent the increase in the heart rate and arterial pressure in response to laryngoscopy and intubation. No cardiovascular responses to laryngoscopy and intubation occurred in the patients treated with alfentanil. No cardiac arrhythmias occurred in the esmolol 3 mg.kg-1 group, whereas the frequency of ventricular ectopic beats was 40% in the saline group and 13-20% in the other groups.

Adolescent↗

PubMed1994

Prevention of nausea and vomiting with transdermal hyoscine in adults after middle ear surgery during general anaesthesia.

In a double-blind, randomized study, we have compared the efficacy of transdermal hyoscine in the prevention of nausea and vomiting with placebo in 60 young, ASA I-II patients after middle ear surgery during general anaesthesia. In the placebo group, 27% and 43% of patients suffered from nausea and vomiting, respectively, during the first 24 h after anaesthesia. The corresponding values for both symptoms in the hyoscine group were 10% (P < 0.001 between groups). The frequency of side effects was similar in both groups. The results suggest that transdermal hyoscine is a useful prophylaxis against nausea and vomiting after middle ear surgery.

Administration, Cutaneous↗

PubMed1993

QT interval, heart rate and arterial pressures using propofol, thiopentone or methohexitone for induction of anaesthesia in children.

The effects on corrected QT interval (QTc), heart rate and arterial pressure were studied after induction with propofol 1.5, 2 or 2.5 mg.kg-1, thiopentone 5 mg.kg-1 or methohexitone 2 mg.kg-1 in 123 ASA class I or II children undergoing outpatient otolaryngological surgery. Premedication consisted of oral midazolam and atropine. The children were randomly allocated to one of the three propofol groups or to the thiopentone or methohexitone group. After injection of the intravenous anaesthetic, the QTc interval was significantly prolonged after propofol 2.5 mg.kg-1. Thirty seconds after suxamethonium 1.5 mg.kg-1, a significant prolongation of the QTc interval occurred in the thiopentone and propofol 1.5 and 2 mg.kg-1 groups. After intubation, no further prolongation of the QTc interval occurred in any of the groups. Heart rate increased significantly after the barbiturates but not after propofol. Systolic arterial pressure decreased significantly after propofol 1.5 and 2.5 mg.kg-1. In all groups a cardiovascular intubation response occurred. Bradycardia and junctional rhythm occurred in 4% of the children in both barbiturate groups and in 19-29% in the propofol groups. It is concluded that propofol causes prolongation of the QT interval and results in a higher incidence of bradycardia and junctional rhythm than the barbiturates.

Anesthesia, Intravenous↗

PubMed1993

Evaluation of postural stability by computerised posturography following outpatient paediatric anaesthesia. Comparison of propofol/alfentanil/N2O anaesthesia with thiopentone/halothane/N2O anaesthesia.

Simple clinical tests, like Romberg's test or a walking test, have proved to be inadequate guidelines for safe discharge after outpatient anaesthesia. A randomised study was therefore planned to compare postural stability measured by computerised posturography in 31 oral midazolam-atropine premedicated children aged 6.9 (s.e. 0.4) years who had been anaesthetised with either propofol/alfentanil/N2O or thiopentone/halothane/N2O. The sway velocity of the children was measured before premedication and 1, 2 and 3 h after the end of anaesthesia. Results show that sway velocity had returned to baseline values 3 h after the end of anaesthesia in all children who had received propofol/alfentanil/N2O and in 12 of the 15 children who had received thiopentone/halothane/N2O. The quantified version of the Romberg test performed with eyes open or closed was not impaired after anaesthesia, compared with the control values, indicating that in children poor equilibrium is not compensated by vision. The clinical recovery with respect to the times to eye opening, to responding to command or to being fully awake did not differ between the two anaesthesia methods. On the basis of recovery assessed by postural stability, propofol/alfentanil/N2O anaesthesia was not preferable to thiopentone/halothane/N2O anaesthesia after minor paediatric otolaryngological surgery.

Alfentanil↗

PubMed1993

Tracheal intubation after induction of anaesthesia with propofol, alfentanil and lidocaine without neuromuscular blocking drugs in children.

In a double-blind study, intubating conditions and haemodynamic responses were assessed in two age-groups of 45 ASA I-II children, with mean ages of 2.4 and 6.3 years, premedicated with oral midazolam and atropine. The children were randomly allocated to one of three groups: alfentanil 20 micrograms.kg-1 + lidocaine 1 mg.kg-1 (Alf20 + Lign); alfentanil 20 micrograms.kg-1 (Alf20); or alfentanil 40 micrograms.kg-1 (Alf40), followed by propofol 3.5 mg.kg-1 in the children aged 1-3 years and 3.0 mg.kg-1 in the older children. Intubating conditions, 40 s after the administration of propofol, were assessed as good, moderate or impossible on the basis of jaw relaxation, ease of insertion of the endotracheal tube and coughing during intubation. In the younger age group the frequencies of good, moderate or impossible intubating conditions were 87, 13 and 0% in the Alf40, 40, 60 and 0% in the Alf20 (P < 0.05 compared to the Alf40 group) and 53, 47 and 0% in the Alf20 + Lign group. In the older age group the corresponding frequencies were 60, 33 and 7% in the Alf20 + Lign, 47, 53 and 0% in the Alf20 and 47, 40 and 13% in the Alf40 group. All the drugs prevented any increase in arterial pressure and heart rate after tracheal intubation. The QTc interval of the ECG was always in the normal range. Clinically important bradycardia did not occur. In conclusion, the best intubating conditions occurred after propofol 3.5 mg.kg-1 and alfentanil 40 micrograms.kg-1 in the younger age group.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗

PubMed1992

Injection pain, cardiovascular changes and recovery following induction of anaesthesia with propofol in combination with alfentanil or lignocaine in children.

The effect of pretreatment with alfentanil 10 (Alf10), 15 (Alf15) or 20 (Alf20) micrograms.kg-1 on reducing injection pain caused by propofol was compared with lignocaine 10 mg mixed with propofol (Lign). This double-blind, double-dummy and randomized study included 100 children with a mean age of 4.3 +/- 0.6 years, 25 children in each group, undergoing minor otolaryngological surgery. The children were premedicated orally with midazolam 0.5 mg.kg-1 and atropine 0.03 mg.kg-1. Injection pain occurred in 4% in the Lign group. The corresponding figures were 40, 16 and 20% in the Alf10, Alf15 and Alf20 groups, respectively. Both 1% lignocaine 10 mg and alfentanil 15 micrograms.kg-1 reduced injection pain significantly compared with alfentanil 10 micrograms.kg-1. Pretreatment with alfentanil significantly diminished haemodynamic responses to tracheal intubation. Furthermore, the concomitant use of alfentanil and propofol caused transient severe bradycardia and a significant decrease in heart rate after laryngoscopy.

Alfentanil↗

PubMed1992

[Interactions between lithium/rubidium and six muscle relaxants. A study on the rat phrenic nerve-hemidiaphragm preparation].

The cumulative concentration-response curves for alcuronium, metocurine, d-tubocurarine, suxamethonium, pancuronium and vecuronium alone or in combination with lithium or rubidium were measured using indirectly evoked twitch tension in the isolated rat phrenic nerve-hemidiaphragm preparation. In the experiments with lithium and rubidium, 10% and 2% of the sodium ions (118 mmol/l) of Krebs solution were replaced by lithium (11.8 mmol/l = 0.082 g/l) or rubidium (2.36 mmol/l = 0.202 g/l) ions, respectively. At these concentrations, neither lithium nor rubidium alone affected twitch tension. Lithium led to a statistically significant enhancement of the myoneural blocking effects of suxamethonium, pancuronium and vecuronium, but not of the other myoneural blocking drugs. Rubidium behaved similarly to lithium, except that enhancement of the effect of vecuronium was not statistically significant. At higher concentrations, lithium and rubidium alone depressed twitch tension in a dose-dependent manner. Neither myoneural blocking drugs nor lithium and rubidium affected the directly evoked twitch tension. It is concluded that myoneural blocking drugs, especially the newer ones, should be used with caution in patients receiving lithium or other alkali metal therapy as it is not known what interactions may arise.

Animals↗

PubMed1991

Injection pain, intubating conditions and cardiovascular changes following induction of anaesthesia with propofol alone or in combination with alfentanil.

In a double-blind study, propofol (P) 2-2.5 mg.kg-1 preceded by saline (Sal) or alfentanil (A) 20-30 micrograms.kg-1 was used for anaesthetic induction in 59 young patients of ASA physical class I or II, premedicated with oxycodone 0.1 mg.kg-1 and atropine 0.01 mg.kg-1 i.m. The patients were randomly allocated to one of the four groups: Group 1 Sal + P2.5, Group 2 A20 + P2.5, Group 3 A30 + P2.5 and Group 4 A30 + P2. Pain on injection of propofol occurred in 67, 36 and 7% of the patients in the Sal + P2.5, A20 + P2.5 and A30 + P2 groups, respectively, but not at all in the A30 + P2.5 group. Intubating conditions were assessed as good, moderate, poor or impossible on the basis of jaw relaxation, ease of insertion of the tube and coughing on intubation, each on a three-point scale. In impossible cases, suxamethonium was used. In the Sal + P2.5 group, the frequencies of good, moderate, poor and impossible intubating conditions were 0, 38, 8 and 54%, respectively. The corresponding figures in the A30 + P2.5 group were 43, 46, 7 and 14% (P less than 0.05 between the groups). The other groups did not differ significantly from the Sal + P2.5 group. After injection of propofol, both systolic and diastolic arterial pressures decreased significantly in all other groups, with the exception of diastolic pressure in the Sal + P2.5 group, whereas heart rate did not differ from the control level. After intubation, systolic arterial pressure increased statistically significantly in the Sal + P2.5 and A30 + P2 groups and diastolic arterial pressure in all other groups with the exception of the A30 + P2.5 group when compared with the corresponding preceding values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1991

Haemodynamic responses and prolongation of QT interval of ECG after suxamethonium-facilitated intubation during anaesthetic induction in children: a dose-related attenuation by alfentanil.

The haemodynamic response to endotracheal intubation and changes in the QT interval of ECG during anaesthetic induction were studied in 68 healthy children (5.5 years). The children were pretreated double-blindly with either alfentanil 10 micrograms/kg (A10), 25 micrograms/kg (A25), 50 micrograms/kg (A50) or saline (control) (17 children in each group) i.v. 1 min before thiopentone 5 mg/kg. The trachea was intubated after suxamethonium 1.5 mg/kg. Central nervous system excitation was seen in four of 17 and in one of 17 children after alfentanil 50 and 25 micrograms/kg, respectively. After intubation, heart rate increased significantly in the control group, remained at initial levels in the A10 and A25 groups and decreased in the A50 group. A pressor response to intubation was seen in the control and A10 groups. The QT interval was significantly prolonged after suxamethonium in the control and A10 groups, but remained at baseline levels in the A25 and A50 groups. Ventricular ectopic beats were only seen in 2/17 children in the control group. In conclusion, alfentanil 25 microgram/kg is ideal for preventing the haemodynamic response to endotracheal intubation and prolongation of the QT interval, a sign of sympathoadrenal activation, before induction of intravenous anaesthesia in children.

Alfentanil↗

PubMed1991

Oral atropine enhances the risk for acid aspiration in children.

Two modes of administration of an anticholinergic drug were compared in 58 healthy children undergoing adenoidectomy. The study was double-blind and randomized. All children were premedicated with oral midazolam 0.5 mg/kg. Twenty-nine children received oral atropine 0.03 mg/kg (Group A) and the rest were given i.v. glycopyrrolate 0.005 mg/kg at the induction of anaesthesia (Group G). In Group A, of 29 children, the stomach was empty in 2, pH was less than 2.5 in 23, the gastric volume was greater than 0.4 ml/kg in 19, and both these risk factors were present in 17 children. The same figures in Group G were 5 (NS), 14 (P less than 0.05), 10 (P less than 0.05) and 9 (P less than 0.05) children, respectively. The antisialagogue effect was similar in both groups.

Administration, Oral↗

PubMed1991

Comparison of inhalation induction with isoflurane or halothane in children.

Thirty-six children (mean age 2.4 years) premedicated with oral chloral hydrate 70 mg kg-1 and atropine 0.03 mg kg-1 were anaesthetized with either 3.75% isoflurane or 2.5% halothane in 70% nitrous oxide in oxygen. The eyelash reflex disappeared in 39 +/- 7 s (mean +/- SD) with isoflurane and in 56 +/- 16 s with halothane (P less than 0.001). Tachypnoea was seen with both anaesthetics. Coughing, breath holding, stridorous breathing and respiratory depression were seen during isoflurane but not during halothane induction (P less than 0.01). In nine of 20 children anaesthetized with isoflurane, the ventilation had to be assisted before intubation. Endotracheal intubation was possible in 224 +/- 35 s with isoflurane and in 281 +/- 64 s with halothane (P less than 0.01). Intubating conditions were satisfactory in 80% of the children anaesthetized with either volatile agent. Cardiovascular responses to endotracheal intubation were minimal with both anaesthetics. No cardiac dysrhythmias were noted. Heart rate was higher during isoflurane than during halothane induction. Diastolic arterial pressure was lower during isoflurane than during halothane induction immediately and 5 min after intubation.

Analysis of Variance↗

PubMed1990

Unconsciousness associated with midazolam and erythromycin.

An 8-yr-old boy suffering from an asymptomatic ventricular septal defect was given erythromycin for antibiotic prophylaxis before adenoidectomy. Sixty minutes after premedication with oral midazolam 0.5 mg kg-1 and oral atropine 0.03 mg kg-1, an infusion of erythromycin 400 mg was started. When 200 mg of erythromycin had been infused, the patient lost consciousness, but other vital functions remained normal. After 45 min, he awakened spontaneously. At the time the plasma concentration of midazolam was 134 ng ml-1. In order to investigate possible interactions between midazolam and erythromycin, we studied the pharmacokinetics of midazolam in six children of the same age undergoing minor otolaryngological surgery. The plasma concentration of midazolam in the patient who lost consciousness was significantly greater than in six other children without concomitant administration of erythromycin. The altered pharmacokinetics of midazolam may result from reduced hepatic clearance of midazolam caused by an enzyme inhibiting drug, erythromycin.

Adenoidectomy↗

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

Cimetidine and ranitidine do not affect enflurane metabolism in surgical patients.

Hepatic cytochrome-P-450-linked microsomal metabolism is inhibited by cimetidine, and to a lesser extent by ranitidine. Such an inhibition might protect against the metabolite-related toxicity of inhalation anesthetics. However, in comparison with the values measured in a control group, neither cimetidine (600 mg p.o. + 200 mg i.m.) nor ranitidine (150 mg p.o. + 50 mg i.m.), both administered 11-12 h before anesthesia, inhibited enflurane metabolism as assessed by the increase in plasma inorganic fluoride concentration and urinary fluoride excretion in 21 ASA I patients anesthetized with enflurane (end-tidal concentration 0.5 +/- 0.05% for 2-6 h). The inorganic fluoride concentration in the gastric juice remained low in all groups.

Aged↗

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↗