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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)

The respiratory and circulatory conditions in high frequency positive pressure ventilation (HFPPV) in the dog have been investigated previously. By means of expiratory resistance a positive intratracheal pressure was maintained throughout the respiratory cycle. Adequate ventilation was achieved at low intratracheal and transpulmonary pressures.A clinical test of this form of ventilation was conducted in connection with routine surgery in 15 patients; in 11 patients neuroleptic analgesia and in four patients thiopental sodium anaesthesia and pethidine analgesia was combined with oxygen-nitrous oxide ventilation (30 % 0, in N 2 0 ) . Muscle relaxants were given to all patients except one.The patients were ventilated, with the same gas mixtures, either manually (anaesthetic apparatus), with the Engstrom Respirator (ER-300) or by HFPPV. HFPPV was studied at different frequencies and different relative insufflation times ( 15-35 % of the period time). Expiratory minute volumes, intratracheal pressures (HFPPV) and tubing pressures (ER-300), arterial pH, Pco;?, Po2, base excess and standard bicarbonate were determined.During HFPPV there was a positive intratracheal pressure throughout the respiratory cycle. I n all patients adequate alveolar ventilation was obtained with HFPPV. The changes both in the blood gases and acid-base status, and in the intratracheal pressures and expiratory volumes, in relation to frequency and insufflation time, agreed in principle with those observed in the previous animal experiments.During HFPPV, i. e. with low intratracheal pressures, the patients maintained an adequate arterial Po2 and to judge from the pH and Pcoe this did not necessitate hyperventilation.