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Biomedical subjects

M Tuominen

Publications and source records attributed to M Tuominen.

At least 91 records · Page 5Linked to original sources

Effect of aspiration of cerebro-spinal fluid on spinal anaesthesia with isobaric 0.5% bupivacaine.

The effect of changing the volume of cerebro-spinal fluid (CSF) before spinal anaesthesia with 3 ml of isobaric 0.5% bupivacaine was investigated in 60 elderly (58-77 years) orthopaedic or urological patients. The patients were randomly allocated to three groups. They received the spinal anaesthetic either with or without the aspiration of 3 ml of CSF. In the third group a mixture of 3 ml of aspirated CSF and 3 ml of 0.5% isobaric bupivacaine was given. Pin-prick analgesia and motor block were tested during the induction and recovery. The only statistically significant difference between the groups was in the time-lag from administration to maximum spread of pin-prick analgesia, which was shortest in the group without aspiration (mean 19.5 min, other groups 29-30 min). The mean maximum level of analgesia was T6-T7 in each group. The anaesthesia was satisfactory in most cases. One death occurred because of a massive pulmonary embolism. The clinical significance of aspirating CSF before attempting spinal anaesthesia with 3 ml of 0.5% isobaric bupivacaine was found to be small.

Aged↗

Droperidol prevents and treats nausea and vomiting after enflurane anaesthesia.

One hundred and twelve women undergoing elective orthopaedic surgery under enflurane anaesthesia were given, in a double-blind random fashion, 2.5 mg of droperidol i.m. before anaesthesia, or 1.25 mg of droperidol or a saline placebo i.v. at the end of anaesthesia in an attempt to prevent post-operative vomiting. The administration of droperidol 1.25 mg (for those receiving initially 1.25 mg of droperidol) or saline (for those receiving initially 2.5 mg of droperidol or saline) was repeated i.m. during the 24 post-operative hours in a blind manner if the patient complained of nausea, retched or vomited. Significantly fewer patients (P less than 0.05) given i.m. or i.v. droperidol had emetic symptoms than patients given saline. Furthermore, 51% of the patients given saline needed additional doses of saline, whereas only 27% of the patients given i.m. and 36% of the patients given i.v. droperidol required a second dose (P less than 0.05 between groups). More of the patients given saline (23%) than those given droperidol (8% to 9%), as a blind drug (P less than 0.05), needed to be given additional droperidol as a known anti-emetic because of the failure of the blind drug to prevent or treat symptoms. It is concluded that droperidol given either as a single dose of 2.5 mg i.m. or in repeated doses of 1.25 mg i.v. is effective in the prevention and treatment of post-operative nausea and vomiting after enflurane anaesthesia.

Adult↗

Influence of age on spinal anaesthesia with isobaric 0.5% bupivacaine.

Possible correlations between age and certain characteristics of spinal blockade with plain bupivacaine were investigated in 124 patients, ages ranging from 15 to 92 yr. Three millilitre of 0.5% solution (sp. gr. 1.000 at 37 degrees C) was injected at the L3-L4 interspace. There were great individual variations in all age groups, but the maximum spread of analgesia increased with age, although the correlation was poor (P less than 0.05). The spread of analgesia to L2 and L3 segments in the oldest patients (greater than or equal to 70 yr) was about twice as fast as that in the youngest (less than 30 yr). Complete motor blockade of the lower extremities developed most rapidly in the oldest patients (greater than or equal to 80 yr; mean 11 min), while in patients younger than 50 yr the mean time to complete motor block was approximately doubled. The mean sensory recovery of the two uppermost segments and the mean sensory recovery of the S1 segment did not correlate significantly with age. The decrease of systolic arterial pressure was correlated with the height of the sensory block only in the oldest (greater than or equal to 80 yr) patients. Post-spinal headache was encountered in two patients (1.6%).

Adolescent↗

Blood levels of bupivacaine after single dose, supplementary dose and during continuous infusion in axillary plexus block.

The material consisted of 25 patients undergoing orthopaedic or plastic surgery of the upper extremity, including seven cases of replantation surgery. The total doses of bupivacaine, 150-267 mg as a single dose, 280-440 mg as a supplementary dose and 247-629 mg as a continuous infusion, resulted in maximum venous concentrations of 0.68-3.33 micrograms/ml, 1.21-2.44 micrograms/ml and 0.51-1.89 micrograms/ml, respectively. These usually occurred 30-60 min after the injection of bupivacaine and always following the second injection when a supplementary dose was needed. The highest individual value noted occurred 15 min after single injection, possibly as a result of an exceptionally rapid absorption. Despite the high doses and the rather high venous peak concentration of bupivacaine in some of the patients, no toxic side-effects were observed during the block or during the recovery period.

Adolescent↗

Effect of posture and some c.s.f. characteristics on spinal anaesthesia with isobaric 0.5% bupivacaine.

The effect of the sitting position (0, 2.5, 5.0 or 7.5 min), during and after the injection of 3 ml of 0.5% isobaric bupivacaine-HCl, on the segmental spread of spinal analgesia was studied in 40 patients. Ten patients injected in the lateral horizontal position acted as controls. The spread of analgesia was significantly greater in those who sat for 2.5 min or more compared with those who were immediately put in the supine position. Prolongation of the sitting time did not produce a higher analgesic block. The motor block was complete in all patients; its duration was significantly longer in the horizontal group than in all the sitting groups. There was no significant correlation between the different c.s.f. indices (pressure, protein and chloride ion concentration pH, and specific gravity) and the spinal block.

Adult↗

Effects of posture on the spread of spinal anaesthesia with isobaric 0.75% or 0.5% bupivacaine.

In a double-blind study the effects of posture on the spread of 3 ml of isobaric bupivacaine 5 and 7.5 mg ml-1 were compared after intrathecal injection in 40 patients undergoing orthopaedic surgery. Three millilitre of isobaric bupivacaine 7.5 mg mg-1 administered with the patient in a sitting position during and for 2.5 min after injection produced the highest spread of analgesia (T4). Horizontal posture, and the smaller dose in both positions, resulted in spread of analgesia to T7-8. Motor block in the legs was good in all cases. Horizontal posture at the time of injection resulted in the longest mean duration of analgesia and motor block, although there was no statistically significant difference in mean times between the groups. The longest mean duration of pin-prick analgesia (329 +/- 23 min) was in the patients injected in the horizontal posture with bupivacaine 7.5 mg ml-1. The course of anaesthesia and recovery were uneventful in all patients.

Aged↗

Bupivacaine blood levels after intravenous regional anesthesia of the arm.

Toxic reactions have been reported in patients after immediate release of the tourniquet cuff following intravenous regional anesthesia (I.V.R.A.) with bupivacaine. In this study we induced I.V.R.A. with 0.25% bupivacaine, mean dose 1.8 mg/kg (range 1.4-2.6 mg/kg). The patients were divided into two groups according to the method used to release the cuff; these were immediate release (Group I), or release with an "on and off" technique (Group II). The highest venous bupivacaine concentrations (max. 2.72 micrograms/ml) were measured 10 min after the ischaemic period, but there were not statistically significant differences between the two groups (the highest mean concentration was 0.91 microgram/ml in Group I and 0.93 microgram/ml in Group II). There was a difference in the bupivacaine concentrations between the subgroups of short (less than 40 min) and long (greater than 90 min) periods of ischaemia, but it was not significant. The fact that the bupivacaine concentration peak appeared later and was higher in the latter group might be associated with the lower pH (long ischemia) and its effect on the bupivacaine binding in the tissues. No toxic symptoms were recorded in the 40 patients in our study. Additional analgesics were needed in 11 cases and in 8 of these the reason was an uncomfortable feeling under the cuff. It is concluded that bupivacaine in doses of 1.4 to 2.6 mg/kg is safe for I.V.R.A. The tourniquet cuff could be released without toxic reactions. However, after long periods of ischaemia, the possibility of delayed, potentially toxic blood bupivacaine concentrations is higher.

Adult↗

Comparison of haemodynamic effects of pethidine and anileridine in anaesthetised patients.

Haemodynamic effects of equianalgesic doses of pethidine (1 mk kg -1) and anileridine (0.25 mg kg -1) were compared in patients with coronary artery disease, after induction of anaesthesia with flunitrazepam - N2O - pancuronium. Contrary to previous findings made in conscious patients, these analgesics produced a moderate circulatory depression. Heart rate, cardiac index and rate-pressure product were decreased by both drugs, and anileridine alone decreased mean arterial pressure. The only statistically significant differences in the haemodynamic changes between the two groups were those in pulmonary capillary wedge pressure and rate pressure product, which were slightly lower after anileridine than after pethidine.

Anesthesia↗

Effect of smoking on the central circulation at rest and during exercise as studied by radiocardiography.

The pulmonary vessels are the first target of tobacco smoke in the circulatory system, but the functional changes occurring in the pulmonary circulation are poorly understood. Hence 46 volunteers were studied by radiocardiography under the following conditions: 1. At rest before and after smoking 2 cigarettes (15 men); 2. After repeated ergometer exercise (5 min, 100 W) with and without smoking (13 men); and 3. Control experiments under the corresponding conditions without smoking (18 subjects). A significant increase occurred in heart rate, cardiac output and systolic arterial blood pressure after smoking when at rest, but an almost significant decrease in pulmonary dispersion volume , whereas the heart rate and pulmonary capillary pressure attained significantly higher values after than before smoking in the exercise tests, with a significant decrease observed in stroke volume, pulmonary blood volume and pulmonary dispersion volume. It is concluded that smoking impairs physical performance, increases pulmonary capillary pressure and reduces pulmonary blood volume and probably the number of open capillaries.

Adult↗

Quantitative radiocardiographic evaluation of cardiac dynamics in man at rest and during exercise.

113Inm radiocardiography in conjunction with a gamma camera and a digital computer is applied to measurements of cardiac output, stroke volume, ejection fraction, end-diastolic volume, pulmonary blood volume, pulmonary transfer time and dispersion both at rest and during muscular exercise. A modified gamma function is used in calculations of radiocardiographic curves. In twelve supine male subjects the maximal increase of cardiac output was 220%, stroke volume 30%, ejection fraction 15%, and pulmonary blood volume 30%. The present method provides a non-invasive tool for cardiovascular examinations during exercise.

Adult↗

Comparison of haemodynamic effects of pethidine and anileridine in patients with coronary-artery disease.

The circulatory effects of anileridine, a derivative of pethidine, have been little studied. Therefore we compared the haemodynamic effects of equianalgesic doses of pethidine (1 mg/kg i.v.) and anileridine (0.25 mg/kg) in matched patients requiring myocardial revascularization. Cardiac output was significantly increased 5 min after the administration of pethidine, mainly due to an increase in heart rate. A transient rise in the systolic pulmonary-arterial pressure was found after anileridine. No remarkable changes were found in systemic arterial pressures, central venous pressure, balloon-occluded pulmonary-arterial pressure, stoke volume, systemic or pulmonary vascular resistances and derived oxygen consumption. Further, 20 min after drug administration, there were no significant differences in any circulatory parameters between the two groups. One patient developed acute cardiac failure after anileridine, though as he had very severe coronary heart disease it remains an open question whether this was spontaneous or drug-induced. Since the rate-pressure product tended to increase after pethidine, this drug may not be considered an ideal analgesic for patients with ischaemic heart disease. Anileridine had less influence on this variable. Since the circulatory effects of pethidine seem to depend on the haemodynamic status of the patient, the haemodynamic properties of anileridine may also deserve further investigation.

Adult↗

Comparison of the effect of anileridine and pethidine on the intracholedochal pressure during constant fluid perfusion.

Anileridine and pethidine have a spasmolytic action on animal intestine. Pethidine is known to have a spasmogenic effect at the choledocho-duodenal junction of man, but there is no study of the effect of anileridine on the biliary tract. In the present study the effects of anileridine and pethidine on the intracholedochal pressure during constant fluid perfusion in man were compared. The maximal elevation of the choledochal passage pressure was significantly greater after anileridine than after pethidine. However, the difference between anileridine and pethidine seemed to be less than that reported previously between morphine and pethidine. The effect of anileridine was of shorter duration than of pethidine. Anileridine and pethidine are not ideal analgesics when the normal activity of the biliary ductal system has to be maintained in pain or during cholangiography.

Adult↗

Comparison of anileridine and pethidine in patients with pain following upper abdominal surgery.

The analgesic potency of anileridine compared with pethidine was found to be 4:1 by measuring the effect on withdrawal movements resulting from pinching of the skin or surgery during N2O + O2 anaesthesia. The potency ratio was examined postoperatively as well. Sixty patients who had undergone upper abdominal surgery with standard anaesthesia were studied in a double-blind, between-patient two dose comparison. Each patient and an observer graded the degree of pain relief. Here again, anileridine proved 4 times as potent as pethidine. With higher doses the response to anileridine was of shorter duration than was the response to pethidine. Respiratory depression was very similar after equianalgesic doses. Blood pressure and pulse rate remained stable. The total incidence of side effects was higher after pethidine.

Abdomen↗

The effects of beta-adrenergic agents on the contractility of transplanted canine heart.

The effects of isoprenaline and adrenalin on the myocardial contractility of transplanted heart were studied in 6 mongrel dogs which had undergone orthotopic cardiac transplantation. Isoprenaline and adrenaline produced a fall in end-diastolic and end-systolic volumes, and an increase in stroke volume, cardiac output and velocity of contraction when the heart rate was increased. Similar changes were observed in 4 mongrel dogs tested as controls, with the exception of a less pronounced increase of cardiac output after administration of isoprenaline and adrenalin and a fall in stroke volume associated with a higher acceleration of heart rate after administration of isoprenaline. These minor differences between the transplanted and intact heart were thought to be a reflexion of the increased blood volume following heart transplantation.

Animals↗

Comparison of anileridine and pethidine in preventing pain responses during nitrous oxide-oxygen anaesthesia.

The analgesic potency of anileridine and pethidine was compared in 28 patients by measuring their effect on withdrawal movements caused by pinching of the skin or by surgery during N2O + O2 anaesthesia. It appeared that anileridine is 3.5 to 4 times as potent as pethidine on a weight basis. In equianalgesic doses the incidence of side effects was equal after both drugs.

Adjuvants, Anesthesia↗

Comparison of double-hole and single-hole pencil-point needles for spinal anesthesia with hyperbaric bupivacaine.

BACKGROUND AND OBJECTIVES: The use of thin single-hole pencil-point (SHPP) spinal needles may be a reason for subarachnoid maldistribution of local anesthetic. A new double-hole pencil-point (DHPP) needle may be preferable because of a theoretic more uniform initial distribution of local anesthetic. METHODS: This was a prospective, double-blinded study of 50 patients randomly selected to have spinal anesthesia using either single-hole 27-gauge (B. Braun, Melsungen, Germany) or double-hole 26-gauge (A.L.B. Medical Inc., U.S.A.) pencil-point needles. The former were inserted with the side port directed caudally and the latter with openings in both caudal and cranial direction. Two milliliters of hyperbaric 0.5% bupivacaine were injected in 1 minute, and sensory and motor block were studied at regular intervals during spinal anesthesia. All patients were interviewed on the first (personal) and the seventh (mailed questionnaire) postoperative day. Furthermore, microscopic inspection of the spinal needles was performed. RESULTS: There were no statistically significant differences in sensory or motor block levels between the two needle types at any time during spinal anesthesia. Likewise, there was no difference in the duration of spinal block. The postanesthetic side effects (headache, backache, pricking, numbness, weakness) were similar in both groups. Light and electron microscopic examination showed resistance of the SHPP needles to tip damage. On the other hand, the DHPP needle tips seemed to be distorted quite frequently, and, even in unused needles, the tip was blunt and asymmetric. CONCLUSION: There was no difference between the spread of analgesia using either SHPP or DHPP spinal needles. The DHPP needles appear to be vulnerable to tip damage from mechanical contact.

Adult↗