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Biomedical subjects

M Tuominen

Publications and source records attributed to M Tuominen.

At least 55 records · Page 3Linked to original sources
PubMed1992

Effect of speed of injection of 0.5% plain bupivacaine on the spread of spinal anaesthesia.

We have studied the influence of two different speeds of injection on the spread of spinal anaesthesia of bupivacaine in 40 orthopaedic patients. In a random order, 0.5% plain bupivacaine 3 ml was administered in 10 or 180 s into the subarachnoid space using a 27-gauge needle with the patients in a lateral horizontal position. The slower speed produced a higher spread of spinal anaesthesia (median difference 2.5 segments, P < 0.05).

Adult↗
PubMed1992

Effect of continuous interscalene brachial plexus block on diaphragm motion and on ventilatory function.

Interscalene block may cause phrenic nerve block and decreased diaphragmatic motion. We evaluated the effect of continuous interscalene block on ventilatory function and diaphragmatic motion. We studied ten patients scheduled for surgery or manipulation of the shoulder. Preoperatively, the patients underwent spirometry and double-exposure chest radiography. They received an interscalene block with 0.75% bupivacaine. Thereafter, 0.25% bupivacaine was infused into the interscalene space for 24 h. Spirometry was repeated three times and double-exposure radiography twice. The maximal inspiratory and expiratory pressures were measured repeatedly. Haemoglobin oxygen saturation (SPO2) was monitored with pulse oximetry. The block provided adequate anaesthesia for surgery or manipulation. All patients had a marked ipsilateral paresis of the diaphragm in the radiographs 3 h after the initial block. Twenty-one hours later five patients had diaphragmatic motility comparable to the situation before the block. In the other five patients, the amplitude of diaphragmatic motility on the side of the block was only 4-37% of the values before the block. All patients had a clear reduction in forced vital capacity (FVC), forced expiratory volume in 1s (FEV1) and peak expiratory flow (PEF) 3 and 8 h after the block without signs of dyspnoea. In conclusion, in all our patients interscalene block caused an ipsilateral hemidiaphragm paresis, which in five of ten patients persisted until the end of the continuous block.

Adult↗
PubMed1992

Technical problems associated with the use of 32-gauge and 22-gauge spinal catheters.

Interest in the use of continuous spinal anaesthesia (CSA) has recently increased because of the availability of new, extremely thin catheters. In this study the use of 32-gauge (G) catheters was compared with 22-G catheters in operations on the lower limb and for the administration of intrathecal morphine in the postoperative period in 42 elderly patients. CSA succeeded in 34 cases and 8 patients were anaesthetised with a single-shot spinal method. No general anaesthesia was needed. Technical problems with the subarachnoid puncture with the 19-G needle caused two failures in the 22-G group. In a group of 20 patients, there were five failures with the 32-G catheter, as opposed to one failure with the 22-G catheter in a group of 20 patients. Associated with morphine injection through the 32-G catheter, the syringe or connector was inadvertently disconnected in four cases and a tear of the catheter wall was observed in one case. Such problems did not occur with the 22-G catheter. Postdural puncture headache did not occur, and there was no difference in the incidence of patient-reported postoperative complications between the two groups. It is concluded that both the insertion and maintenance of the thin (32-G) subarachnoid catheters are associated with more technical problems than the 22-G catheter.

Aged↗
PubMed1992

Haemodynamic changes during spinal anaesthesia with slow continuous infusion or single dose of plain bupivacaine.

Forty elderly patients, scheduled for orthopaedic surgery of the hip or knee were studied. Twenty patients received a single-dose spinal anaesthesia with 3 ml of plain 0.5% bupivacaine (SDSA group). Twenty patients received continuous spinal anaesthesia using a 32- or 22-gauge catheter. A bolus of 1.0 ml of plain 0.5% bupivacaine was given to ten patients and 0.5 ml to another ten, continued by an infusion at a rate of 2 ml/h. The spread of analgesia and haemodynamic changes (central venous pressure, arterial pressures, need for sympathomimetic medication) were registered. The mean dose of bupivacaine was 2.9 ml (range 1.5-5 ml) in the CSA group (3.0 ml in the SDSA group). Eight patients in the CSA group needed medication for pain during surgery compared to five patients in the SDSA group (n.s.). The median level of pinprick analgesia at 60 min was T11 in the CSA and T6.5 in the SDSA group (P less than 0.01). The mean maximum decreases in CVP and MAP were quite similar in the CSA and SDSA group (2.1 vs 2.8 mmHg (0.3 vs 0.4 kPa) and 17 vs 21 mmHg (2.3 vs 2.8 kPa), respectively) (n.s.). Six patients in the SDSA group and four patients in the CSA group needed sympathomimetic medication. It is concluded that titration of bupivacaine for spinal anaesthesia caused only minor haemodynamic changes which were similar to those after single-dose spinal bupivacaine.

Aged↗
PubMed1992

Weaning and the histology of the mandibular condyle in the rat.

Eighty-eight Long Evans/Turku rats were used in the study. The effect of the articulatory function on the mandibular condyle was observed histologically during normal growth, when the rat is changing its diet from milk to whole pellets as a part of weaning. Six animals each were killed at the age of 10, 15, 20, 25, 30, 35, 40 and 50 days for histological tissue processing. For further information, 30 animals were fed a soft diet (6 animals each were killed at the age of 25, 30, 35, 40 and 50 days), and 10 animals were fed hardened pellets (2 animals each were killed at the ages of 25, 30, 35, 40 and 50 days). An even and regular transition from mesenchymal cells via immature chondroblasts into mature chondroblasts and hypertrophied chondrocytes was found at 10, 15 and 20 days during normal growth and also at 25, 30, 35, 40 and 50 days when animals were fed a soft diet. This maturing process appeared to be disturbed at the age of 25, 30, 35 and 40 days in the superior aspect of the condyle in animals fed ordinary pellets. The density of the mesenchymal cell layer was decreased, and the amount of intercellular matrix seemed to be evaluated in mesenchymal and intermediate cell layers. These features were later manifest deeper in the cartilage as acellular regions and as cell clusters. The changes were similar but more severe when the animals were fed hardened pellets.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Tooth surface loss and associated factors among factory workers in Finland and Tanzania.

The relative importance of various factors in the occurrence of tooth surface loss was explored in a, cross-sectional study using blind dental examinations. Two samples were drawn; one from Finland, comprising 186 workers from four factories and another from Tanzania of 180 workers from two factories. Among the 326 dentate individuals who participated, 164 were exposed to acid fumes and 162 were not. In Finland, people with tooth surface loss were older and smoked cigarettes less frequently. In Tanzania, those with tooth surface loss were also older and the proportion of subjects with the condition was significantly higher among people not using a commercial toothbrush and those exposed to acids. Among the Tanzanians, exposure to acids increased the probability of tooth surface loss to a high level of significance, and increasing age increased its probability, both among the Finns and the Tanzanians. Both anterior and posterior teeth were affected. It can be concluded that if the exposure to acids from the air breathed is high, the probability of tooth surface loss will increase. It seems that explanatory factors for tooth surface loss from one society cannot be extrapolated to another.

Adult↗
PubMed1991

Plasma concentrations of bupivacaine and two of its metabolites during continuous interscalene brachial plexus block.

An interscalene brachial plexus block was performed via a catheter with 20-28 ml of 0.75% bupivacaine plus adrenaline for surgery of the shoulder region in 12 patients. Constant infusion of 0.25% bupivacaine 0.25 mg kg-1 h-1 was continued for 24 h. During surgery light general anaesthesia, without analgesics, was maintained. Plasma concentrations of total and unbound (free fraction) bupivacaine, desbutylbupivacaine (DBB), 4-hydroxybupivacaine (4-OHB) and alpha 1-acid glycoprotein (AAG) were measured at predetermined intervals during the continuous block. The greatest mean plasma concentrations of bupivacaine were measured at 30 min (1.63 (SD 0.55) micrograms ml-1) and 60 min (1.38 (0.48) micrograms ml-1). There was a small but statistically significant increase in the plasma concentration of bupivacaine between 12 and 24 h of infusion. The mean unbound concentration of bupivacaine in plasma decreased from 0.044 (0.015) microgram ml-1 (3.6 (1.1)% of total bupivacaine concentration) at 3 h to 0.023 (0.011) micrograms ml-1 (2.1 (1.0)%) at 24 h. The AAG concentration in plasma increased by 38% in 24 h. The metabolites DBB and 4-OHB were detectable in plasma from 30 min, with a gradual increase during infusion. At 24 h the mean concentrations of DBB and 4-OHB were 0.33 (0.22) micrograms ml-1 and 0.13 (0.04) micrograms ml-1, respectively. There were no toxic reactions during the blocks.

Adult↗
PubMed1991

Cumulation of bupivacaine, desbutylbupivacaine and 4-hydroxybupivacaine during and after continuous interscalene brachial plexus block.

Desbutylbupivacaine (DBB) and 4-hydroxybupivacaine (4-OHB) are major metabolites of bupivacaine. They may cumulate during continuous infusion blocks. In the present study, all patients received an interscalene brachial plexus block with 20-28 ml of 0.75% bupivacaine plus adrenaline. A catheter was introduced into the interscalene space, and an infusion of 0.25% bupivacaine (5-9 ml/h) was started and continued with ten patients for 24 h and with another ten for 48 h. An infiltration block of the suprascapular and intercostobrachial nerves was performed using 0.5% bupivacaine. Before surgery, light general anaesthesia was induced. For measurement of plasma concentrations of bupivacaine, DBB and 4-OHB blood samples were taken before the block and 30 min, 3 h, 24 h and 48 h after the blocks as well as 30 min, 1 h, 2 h, 4 h and 6 h after the termination of the infusions. The highest plasma concentrations of bupivacaine, mean 1.84 micrograms/ml, were measured 30 min after the block. There was a slight but statistically significant rise in the bupivacaine concentrations between 24 and 48 h. The bupivacaine concentration decreased by 54% and 45%, on average, during the first 6 h following the 24- and 48-h infusions, respectively. On average, the highest DBB concentrations were measured 2 h after the 24-h infusion (0.31 +/- 0.18 micrograms/ml) and 30 min after the 48-h infusion (0.33 +/- 0.13 micrograms/ml). The highest 4-OHB concentrations were measured 1 h (0.18 +/- 0.09 micrograms/ml) and 30 min (0.20 +/- 0.05 micrograms/ml) after the 24- and 48-h infusions, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Associations between the location of the glenoid fossa and its remodeling. An experimental study in the rabbit.

The growth of the glenoid fossa is assumed to follow that of the cranial base. It has been observed recently that distal displacement in association with an obtuse cranial base angle is reduced on remodeling of the fossa anteriorly as a consequence of a more anterior position of the condyle in the fossa. The aim of this investigation was to simulate the increased distal displacement experimentally by causing a premature artificial cranial synostosis. Ten 10-day-old rabbits underwent gluing of the interparietal and temporoparietal sutures. These and ten controls were killed at 50 days for examination, and the articular surface of the right glenoid fossa was marked with a soft metal wire. The skulls were roentgenographed in standardized lateral projection. The articular surface was significantly shallower in relation to the skull base in the experimental group, and the glenoid fossa was located more superiorly and posteriorly. The most likely reason for the more horizontal direction of the articular surface is the more anterior location of the condyle, exerting increased pressure on the eminence. This becomes important, as it has recently been shown that in rabbits this shallowing of the fossa is associated with increased forward growth of the mandible.

Animals↗
PubMed1991

Occurrence of periodontal pockets and oral soft tissue lesions in relation to sulfuric acid fumes in the working environment.

The effect of inorganic acid fumes from the working environment on the occurrence of periodontal pockets and soft oral tissues was investigated in a cross-sectional, blind study. A sample of 186 workers was drawn from 4 factories. Of the 170 participants, 82 were working in departments containing acid fumes, and 88 controls had never worked under such conditions. Of the workers exposed to acid fumes 36.9% and of the controls 30.9% had periodontal pockets. The presence of periodontal pockets increased with age significantly more among the acid-exposed workers than among the controls (p less than 0.0001). Oral mucous membrane lesions were observed among 23.2% of the acid-exposed workers and 21.6% of the controls. The findings suggest that acid fumes in the workplace air do not increase the occurrence of oral mucous lesions but may lead to an increase in the prevalence of periodontal pockets.

Adult↗
PubMed1991

Dental erosion and associated factors among factory workers exposed to inorganic acid fumes.

The occurrence of dental erosion and the relative importance of some related factors were explored in a cross-sectional study, using blind dental examinations. A sample of 186 workers from four factories was drawn. Among the 157 dentate participants 76 were working in departments containing acid fumes and 81 controls had never worked under such conditions. Out of the dentate participants, 20 (12.7% had erosion). Anterior teeth were affected more often than posterior ones. Exposure to acid fumes, increasing age and frequency of intake of fruits increased the probability of dental erosion. It can be concluded that exposure to acid fumes in the work environment is associated with dental erosion especially on anterior teeth.

Acids↗
PubMed1991

Tooth surface loss among people exposed to cement and stone dust in the work environment in Tanzania.

The effect of cement and stone dust on teeth was explored in a cross-sectional study, using blind dental examinations. The sample consisted of 36 workers who had been exposed to to the dust and 62 control workers. Tooth surface loss was observed in 72.2 per cent of the exposed workers and in 48.4 per cent of the controls (P less than 0.03). In both the maxillae (P less than 0.001) and the mandible (P less than 0.02) the amount of tooth surface loss was greater in the exposed workers than in the controls. Both anterior and posterior teeth were affected. These findings indicate that tooth surface loss caused by work-related dust should be considered an occupational hazard.

Adult↗
PubMed1991

Cranial base and the growth of the cranial vault: an experimental study on the rabbit.

Artificial premature synostoses of interparietal, temporoparietal and frontoparietal sutures was induced in 5-day-old rabbits in order to investigate the adaptive capacity of the synchondroseal cartilages. Ten control and 15 experimental animals were killed at the ages of 50 and 100 days. The lengths of occipital and sphenoid bones were significantly increased by 50 days but no longer at 100 days. The angle between the occipital and sphenoid bones was decreased and between the presphenoid and sphenoid bones increased by 50 and 100 days. The results indicate that the growth of the cranial base is to some extent adaptive to the growth of the neural tissues early in postnatal life, but as the growth of the cranial base synchondroses continues much longer than that of the brain the independent growth potential is manifest during the later period.

Animals↗
PubMed1990

Influence of obesity on the spread of spinal analgesia after injection of plain 0.5% bupivacaine at the L3-4 or L4-5 interspace.

Spinal anaesthesia was compared in 40 obese patients (increased body mass index (BMI] and 40 patients with normal BMI when 3 ml of plain 0.5% bupivacaine was injected at either the L3-4 or L4-5 interspace. More extensive cephalad spread of sensory block was achieved in patients with increased BMI compared with patients with normal BMI after injection at both L3-4 and L4-5 (P less than 0.05). The use of the L3-4 interspace instead of L4-5 resulted in a higher mean spread of block in patients with both increased (T4 vs T8) or normal (T9 vs T11) BMI (P less than 0.05). The interindividual variability of the blocks was relatively small in patients with normal BMI injected at L4-5, compared with the three other groups (normal BMI injected at L3-4, increased BMI injected at L3-4 and L4-5). Good anaesthesia was produced in all patients for orthopaedic surgery of the lower extremity. In an obese patient it is recommended that plain bupivacaine be administered at L4-5 instead of L3-4 when extensive spread of the block is to be avoided.

Adult↗
PubMed1990

Spinal anaesthesia with hypobaric 0.19% or plain 0.5% bupivacaine.

Hypobaric 0.19% bupivacaine (plain 0.5% bupivacaine 3 ml + distilled water 5 ml) was compared with 0.5% plain bupivacaine 3 ml for spinal anaesthesia in 29 healthy patients undergoing orthopaedic surgery of the lower extremities. The solutions were injected at the L3-4 interspace in 40 s, and patients were kept sitting for 2 min after injection. The mean maximal cephalad spread of sensory block was to the T1 segment (SD 3.6) and to T8 (4.1) in the hypobaric and plain bupivacaine groups, respectively (P less than 0.0001). The study was interrupted after observing the sensory block of the 29th patient (hypobaric bupivacaine) spread to C2 within 5 min of injection. In most patients, the hypobaric bupivacaine block affected the upper thoracic nerves, and in three patients the cervical nerves also. The high levels of block were accompanied by marked hypotension. The extensive spread of the blocks makes this hypobaric spinal anaesthesia technique unsuitable for routine use.

Adult↗