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Biomedical subjects

J Kyttä

Publications and source records attributed to J Kyttä.

At least 19 recordsLinked to original sources
PubMed1995

Monitoring lung compliance and end-tidal oxygen content for the detection of venous air embolism.

Venous air embolism (VAE) is a recognized complication of surgery performed with the patient in the sitting position, but it occurs also during other operations. We report two cases of VAE, associated with a notable decrease in dynamic lung compliance, detected by side-stream spirometry. Based on these cases, an experiment with 10 pigs was designed to evaluate the usefulness of side-stream spirometry in the diagnosis of VAE. Three doses of air (0.5, 1.0 and 2.0 ml kg-1) were injected via the proximal part of a 5- French gauge pulmonary artery catheter. Only the largest dose was followed by haemodynamic deterioration. Significant increases in end-tidal oxygen content and decreases in dynamic lung compliance were detected with all doses of air together with conventional signs of VAE, that is increases in pulmonary artery pressures and arterial carbon dioxide tensions, and decreases in end-tidal concentration of carbon dioxide. We conclude that continuous monitoring of end-tidal oxygen concentration and side-stream spirometry offers valuable supplements to other monitoring techniques in the detection of VAE.

Adult↗
PubMed1995

Anaphylactoid skin reactions after intravenous regional anaesthesia using 0.5% prilocaine with or without preservative--a double-blind study.

Methylparaben, the preservative of various local anaesthetic solutions, is a potential allergen. In a double-blind study, 0.5% prilocaine with (Citanest, n = 100) or without (n = 100) methylparaben were compared for the occurrence of skin reactions after intravenous regional anaesthesia of the arm in surgical patients. Skin reactions were registered after the deflation of the tourniquet cuff, and intradermal tests were performed with 0.5% prilocaine, 0.1% methylparaben and saline in all patients. Seventeen patients in the Citanest group and four patients in the methylparaben-free prilocaine group developed erythematous skin reactions in the exposed arm after deflation of the tourniquet cuff (P < 0.05, between the groups). The skin symptoms disappeared within an hour and were always restricted to the region which had been anaesthetised. None of the affected patients had positive intradermal tests. The observed skin reactions are probably non-IgE-mediated anaphylactoid reactions in which the presence of methylparaben in the local anaesthetic solution plays a major role.

Adult↗
PubMed1993

Comparison of 2-chloroprocaine and prilocaine for intravenous regional anaesthesia of the arm: a clinical study.

In a double-blind, randomised study of patients scheduled for minor hand surgery 0.5% 2-chloroprocaine (n = 30) and 0.5% prilocaine (n = 30) in a volume of 40 ml were compared for intravenous regional anaesthesia. The onset of sensory and motor block and recovery of sensory block were determined, and the occurrence of side-effects was noted. Twenty-four patients in the 2-chloroprocaine group and 17 in the prilocaine group developed complete sensory block by 15 min after injection (p < 0.05). Complete recovery of sensation was faster after prilocaine (7.1 min) than 2-chloroprocaine (9.8 min) (p < 0.01). Venous irritation and/or urticaria after tourniquet release was observed on 10 occasions in those receiving 2-chloroprocaine and twice in those receiving prilocaine. An increase in heart rate of > 20% above control values occurred in three patients, all of whom had been given 2-chloroprocaine. Clinically, local anaesthetic properties of 0.5% 2-chloroprocaine and prilocaine were similar, but there were more side-effects with the former drug.

Adolescent↗
PubMed1992

The effect of amrinone on recovery from severe bupivacaine intoxication in pigs.

Cardiovascular collapse following intravascular bupivacaine may be resistant to treatment. The effect of amrinone on recovery from bupivacaine-induced severe cardiovascular depression was evaluated in 20 pigs (13-26 kg) in a placebo-controlled randomized double-blind study. Under 0.7% isoflurane anesthesia at FIO2 0.21, 0.5% bupivacaine 2 mg.kg-1.min-1 was infused until mean arterial pressure was 40% of the baseline. Cardiac output and heart rate decreased 75% and 50% from the baseline, respectively. The total dose of bupivacaine was 17 +/- 6 (SD) mg.kg-1 in the control and 19 +/- 5 mg.kg-1 in the amrinone group, resulting in mean plasma concentrations of 42 +/- 6 and 53 +/- 19 micrograms.ml-1, respectively. A bolus of amrinone 4 mg.kg-1 (n = 10) was given immediately after cardiovascular depression, followed by an infusion of 0.6 mg.kg-1.min-1. The control animals received corresponding volumes of physiologic saline (n = 10). After cardiovascular depression, the lungs were ventilated with FIO2 1.0 without anaesthetics or sympathomimetic support. Electric activity of the heart ceased in all control animals in 3.9 +/- 2 min after cardiovascular depression despite atropine and external cardiac compression. All animals in the control group and 5 of 10 animals in the amrinone group were given atropine (P less than 0.01). The animals receiving amrinone survived without cardiac compression (P less than 0.0001). During bupivacaine infusion, all animals developed burst suppression in the electroencephalogram. At the time of cardiovascular depression, in 8 of 10 control and in 6 of 10 amrinone animals, the electroencephalogram was isoelectric.(ABSTRACT TRUNCATED AT 250 WORDS)

Amrinone↗
PubMed1988

Comparison of propofol and methohexitone anaesthesia for thermocoagulation therapy of trigeminal neuralgia.

Propofol and methohexitone given in equipotent doses were compared for anaesthesia for thermocoagulation of trigeminal rootlets. Thirty-eight patients received two to six injections of the induction agents in one therapy session. The increase in arterial blood pressure during coagulation was significantly lower in the propofol group. Respiratory problems were encountered more often in those who received methohexitone (7/19 patients) than propofol (2/19 patients). There was a small but significant increase in blood propofol concentrations as well as in methohexitone plasma concentrations after repeated injections. Individual wake-up times increased to a statistically significant extent in relation to the number of doses of the induction agent but the increases were clinically unimportant (maximal mean change approximately 2 minutes). There were no differences in wake-up times between the two anaesthetic groups.

Adult↗
PubMed1988

Results of a randomized trial of vancomycin prophylaxis in craniotomy.

A single prophylactic dose of vancomycin was given in 143 supratentorial craniotomies with a bone flap and 26 suboccipital craniotomies. No antimicrobial agents were given to two similar groups of patients: 172 with supratentorial craniotomy and 19 with suboccipital craniotomy. The infection rate in the vancomycin groups was significantly lower (p less than 0.013), and bone-flap infections alone, the most common infection after supratentorial craniotomy, were significantly fewer (p less than 0.042). Antimicrobial prophylaxis is recommended only for selected high-risk groups. Since a bone flap is devascularized, its resistance to infection is reduced and, once infected, it usually requires surgical removal. Patients undergoing craniotomy with a bone flap therefore form a high-risk group, and antimicrobial prophylaxis is justified.

Adult↗
PubMed1987

Arterial hypertension associated with the use of a tourniquet with either general or regional anaesthesia.

A hypertensive patient with left cardiac enlargement developed marked hypertension under general anaesthesia, during which time a tourniquet was applied around his thigh. When the tourniquet was released, severe hypotension ensued which responded to therapy. The patient, however, died 16 h later of a myocardial infarction. Because of this incident, the anaesthetic and haemodynamic data of 699 patients who underwent limb surgery with a pneumatic tourniquet inflated for at least an hour were retrospectively examined using multivariate analysis. A 30% increase in systolic and/or diastolic arterial blood pressure occurred in 27% of the total patient material and in 67% of those who had had a general anaesthetic. There was a higher frequency of the occurrence of "tourniquet hypertension" with older age, longer operations and the operation site being the lower rather than the upper limb. Tourniquet hypertension rarely occurred in patients with spinal anaesthesia (2.7%) and brachial plexus blockade (2.5%), while those with intravenous regional anesthesia had a higher incidence (19%) of hypertension.

Adolescent↗
PubMed1987

Comparison between 0.5% bupivacaine with and without glucose in lumbar epidural block for knee surgery.

A double-blind study was performed in 41 patients (ASA I) to compare 0.5% bupivacaine with and without 8% glucose in epidural analgesia. There was no difference in the onset, spread, duration or intensity of the epidural anaesthesias. The absorption of bupivacaine to circulation was similar in both groups. No major complications were noted and the anaesthesias were satisfactory for surgery in all patients.

Adult↗
PubMed1986

Absorption of bupivacaine, etidocaine, lignocaine and ropivacaine into n-heptane, rat sciatic nerve, and human extradural and subcutaneous fat.

Absorption of four amide local anaesthetics, including a new experimental agent, ropivacaine, in n-heptane, rat sciatic nerve and human extradural and subcutaneous fat was studied in vitro. The relative n-heptane/buffer (37 degrees C) partitioning of bupivacaine:etidocaine:lignocaine:ropivacaine was 10:39:1:2.9. The absorption of bupivacaine and etidocaine into nerve tissue was identified at steady state, but in extradural and subcutaneous fat etidocaine was taken up significantly more than bupivacaine. The lowest uptake was with lignocaine, and at steady state its mean concentrations were similar in all three tissues. There was a significantly higher concentration of ropivacaine than lignocaine in all tissues. Mean tissue concentrations of bupivacaine in sciatic nerve and subcutaneous fat, on the other hand, were significantly higher than those of ropivacaine. The ratios of relative mean uptake (mg g-1), at steady state, of bupivacaine, etidocaine, lignocaine and ropivacaine were: sciatic nerve 3.3:4:1:1.8, extradural fat 4.1:8.3:1:2.3 and subcutaneous fat 3.8:10.6:1:1.9, all of which were clearly lower than the theoretical n-heptane/buffer partitioning ratios.

Absorption↗
PubMed1986

Effects of repeated bupivacaine administration on sciatic nerve and surrounding muscle tissue in rats.

The effects of repeated administration of 0.5% bupivacaine or saline into the sciatic notch of rats were studied by light microscopy, electron microscopy and a neurophysiological technique. Very severe myositis, including local necrosis, developed in six of 12 rats treated twice daily with 1 ml bupivacaine for either 3 or 7 days. A 3-h infusion of 1.5 ml 0.5% bupivacaine resulted in minor injury to muscle tissue. A marked degree of disruption and vacuolization of myelin sheaths was evident in nerves exposed to bupivacaine for 3 days. Lymphocyte accumulation was confined to the area surrounding the nervous tissue in 7 of 10 of the preparations from rats treated for 3 days or by a 3-h infusion. No histological changes were detected in nerve and muscle tissue from the opposite extremity exposed to saline. After a recovery period of 3 weeks, no differences in the nerve or muscle histology were seen between samples from bupivacaine- or saline-treated animals. The amplitude of the compound action potential of sciatic nerves was, however, significantly lower after bupivacaine treatment (7 days, 1 ml twice daily). Thus, impaired function may continue despite the lack of histological intraneural injury.

Animals↗
PubMed1986

Steroid hormone receptors in laryngeal carcinoma.

The larynx has long been shown to be a target organ for androgenic steroids in both women and men, and specific androgen receptors have been determined in normal laryngeal mucosa and in laryngeal carcinoma tissue. In this study, samples from 21 primary laryngeal carcinomas, from 4 recurrent laryngeal carcinomas and from 1 cervical metastasis of laryngeal carcinoma were obtained at the time of surgery to assay specific androgen, estrogen, and progesterone receptors. Specific androgen receptors were found in 8 samples (31%). The level of receptors varied from 1.7 femtomoles (fmol) per milligram to 7.3 fmol/mg cytosol protein. Detectable levels of specific estrogen receptors were found in 18 samples (69%) and progesterone receptors in 8 of the 15 samples studied (53%). There was no apparent correspondence with donors' sex, since samples from both females and males contained all kinds of receptors. We know that antiestrogen inhibits the growth of squamous carcinoma cells lines positive for estrogen receptors in vitro and that this effect is reversible with the appropriate hormone. Thus, the relatively high percentage of estrogen and progesterone receptors found in laryngeal carcinoma tissue may open new aspects in the treatment of laryngeal carcinoma with antihormones.

Aged↗
PubMed1986

Effects of continuous epidural administration of bupivacaine through a catheter in pigs.

We studied whether long-term epidural catheter (nylon) placement for bupivacaine administration (morphine in 2 pigs) would cause any pathological changes in the epidural space and spinal cord of pigs. There were similar kinds of slight inflammatory changes in ligamentum flavum and dura mater in bupivacaine-treated (4 ml 0.5% bupivacaine, twice daily for 7 days, n = 8; 16 ml 0.25% bupivacaine infusion in 12 h, n = 3) and morphine-treated (2 mg preservative-free morphine, twice daily for 7 days, n = 2) pigs compared with corresponding control pigs (saline, n = 8) 24 h after treatment. There were minimal inflammatory changes in one of the two bupivacaine-treated pigs recovering for 3 weeks. In one of the bupivacaine pigs there was a bacterial infection (Staphylococcus aureus) all along the epidural catheter. In this pig the overall level of bupivacaine plasma concentrations after an injection decreased stepwise during the 7-day period (sampling at 2-day intervals). In the other pigs treated for 7 days, the level of bupivacaine concentrations did not change markedly from first sampling to later samplings. It is probable that inflammatory changes in the epidural space, following prolonged administration of bupivacaine and morphine, are largely due to catheter irritation.

Anesthesia, Epidural↗
PubMed1984

Anaesthesia for patients with multiple sclerosis.

The types of anaesthesia administered to 56 multiple sclerosis patients undergoing surgery in the different departments of the Helsinki University Central Hospital (HUCH) during a ten year period from 1973 to 1982 were studied. The perioperative and postoperative events were analyzed in relation to the method of anaesthesia. Infiltration methods (24 patients), mainly for thalamotomy, were well tolerated. General anaesthesia (28 patients), with or without the use of succinylcholine, seemed not to cause any circulatory or respiratory troubles to the MS-patients. In four patients who were given regional anaesthesia (2 spinal, 3 epidural) marked by hypotension, quite resistant to intravenous vasopressor treatment was observed. No deterioration of the multiple sclerosis was noted postoperatively which could be related to the anaesthesia.

Adult↗
PubMedDate not supplied

Cardiovascular and central nervous system effects of co-administered lidocaine and bupivacaine in piglets.

The toxic profile of bupivacaine (1 mg/kg/minute) when administered intravenously alone or with lidocaine (1 mg/kg loading dose, then 1 mg/kg/minute) was examined in 12 2-day-old pigs anesthetized with 70% N2O/30% O2 and paralyzed with 0.15 mg/kg pancuronium. Bupivacaine doses producing arrhythmias, seizures, isoelectric EEG and asystole were about 24% lower in the lidocaine plus bupivacaine group (n = 6) than in the bupivacaine group (n = 6). However, the incidence of cardiac arrhythmias in the combination local anesthetic group (3/6) was half that in the bupivacaine group (6/6). Administration of lidocaine with bupivacaine under conditions of this study apparently reduces the risk of cardiac arrhythmias and acts along with bupivacaine to produce seizures, cerebral depression (isoelectric EEG) and asystole.

Animals↗
PubMedDate not supplied

Treatment of bupivacaine-induced cardiac arrhythmias in hypoxic and hypercarbic pigs with amiodarone or bretylium.

The treatment of bupivacaine-induced cardiovascular toxicity with amiodarone or bretylium was studied using anesthetized pigs (n = 30). The pigs were given ketamine, glycopyrrolate, enflurane, and pancuronium and made hypoxic (FiO2, 12%; N2O, 88%) and hypercarbic (end-tidal CO2, 7.3-8.0%) before the administration of bupivacaine (4 mg/kg i.v.). The animals were then treated, in a randomized and double-blind fashion, with either amiodarone (n = 10) 10 mg/kg in 5% dextrose solution i.v. followed by a constant infusion of 15 mg/hour, bretylium (n = 10) 20 mg/kg in 5% dextrose solution i.v. followed by a constant infusion of 90 mg/hour, or 5% dextrose solution (n = 10). The animals were resuscitated, if required. After 30 minutes of recovery, the animals that survived were made hypoxic and hypercarbic again and given a second injection of bupivacaine (2 mg/kg IV). Bupivacaine caused marked changes in the ECG; polymorphic ventricular tachycardia (20 cases) or severe bradycardia that resulted in asystole (10 cases). Nine animals out of ten treated with amiodarone survived (stable sinus rhythm, arterial blood pressure at near control level, normocarbia), whereas six animals in the bretylium group and four in the control group died. The difference in survival between the groups was not, however, statistically significant.

Amiodarone↗