A method for determining muscle strength in the lower extremities was developed and its clinical application evaluated in ten elderly, healthy subjects, and also subsequently in one of them during spinal anaesthesia. With the subject lying in the lithotomy position on a modified operating table, muscle strength measurements were made during flexion of the hip, extension of the knee and plantar flexion of the big toe. The electromechanical performance of the apparatus was stable, and the maximum measurement errors observed at loads of 245 and 49 N were 4 and 11% of the deflections, respectively. The subjects underwent repeated muscle strength measurements during a 4-h period without any difficulty. No signs of muscular fatigue were observed. The variation of the measured isometric muscle strength was small and the average coefficient of variation roughly 10%. In the patient receiving spinal anaesthesia, the degree of motor block was determined, and the results are presented graphically. This new method for evaluation of motor block in the lower extremities is a reliable quantitative method for bilateral, three-joint muscle strength measurements, which is also applicable during regional anaesthesia.

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PubMed1985

Bladder function in spinal anaesthesia.

Spinal anaesthesia with bupivacaine (22.5 mg) or with a glucose-containing solution of bupivacaine (20 mg) or tetracaine (15 mg) was given to 21 patients allocated randomly to these three groups. A urodynamic study was performed by CO2 cystometry. It consisted of recording of first sensation of bladder filling, sensation of full bladder, strength of maximal detrusor contraction, bladder capacity and urethral pressure. At the same time, using a quantitative method for measuring muscle strength, the motor block was evaluated for three separate movements--hip flexion, knee extension and plantar flexion of the big toe. After the spinal injection, the micturition reflex was rapidly blocked. One minute after the injection, eight patients experienced no strong desire to void when the bladder was overfilled, and 5 min after the injection bladder paralysis was present in most patients. The length of time from spinal injection to complete recovery of detrusor strength was 7-8 h and did not differ significantly between the three groups. The level of analgesia lay at or caudal to L5 when the detrusor strength returned. On the average, sensibility (pin-prick) in the sacral segments returned simultaneously with or somewhat earlier than complete recovery of detrusor strength. The muscle strength in the lower limbs was fully restored 40-140 min, on average, before the detrusor strength had completely recovered. There was good correlation between the time of full restoration of hip flexion and detrusor strength in the bupivacaine groups. Urethral pressure was reduced by a mean of 48% and returned to normal either at the same time as or slightly before complete recovery of detrusor strength.(ABSTRACT TRUNCATED AT 250 WORDS)

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PubMed1979

Clinical significance of specific gravity of spinal anaesthetic agents. Two double-blind studies with hyperbaric 5% lidocaine.

In two double-blind studies two hyperbaric 5% lidocaine solutions containing glucose in concentrations of 75 mg/ml and 50 mg/ml, respectively, were compared. The onset and total onset time, spread, intensity, duration of analgesia and motor block were studied. The spinal anaesthesia was given with the patient either sitting or in the lateral recumbent position. A tendency to a longer duration of anaesthesia near dermatomes Th X-L II and L IV-L V was noted in the group of patients in the sitting position and receiving lidocaine with a lower glucose concentration. Otherwise there were no differences between the two lidocaine solutions. The result shows that the glucose concentration can be reduced from 75 to 50 mg/ml in "heavy" lidocaine without any clinical disadvantage. This means a more isotonic solution in relation to the cerebrospinal fluid, resulting in milder osmotic effects on interspinal structures.

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PubMed1975

Plasma concentration of local anaesthetic agents in regard to absorption, distribution and elimination, with special reference to bupivacaine.

Absorption from the injection site, tissue distribution, metabolism and urinary excretion are the factors determining the plasma concentration of local anaesthetic agents. Other factors such as physico-chemical properties of these drugs may have important influences on these processes. An example of this is the difference in tissue distribution and plasma/erythrocyte ratio as well as an increase in plasma concentration of bupivacaine seen in acidosis. The importance for the plasma concentration, of protein binding, vasoactivity and the effect of depressed circulation are discussed.

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PubMed1974