PULMONARY-FUNCTION AND HEAD LIFT DURING SPONTANEOUS-RECOVERY FROM PIPECURONIUM NEUROMUSCULAR BLOCK

We have studied in seven healthy conscious volunteers the correlation between the electromyographic (EMG) and clinical criteria used to iden tify adequate recovery from sub-paralysing doses of pipecuronium. Pipe curonium (mean dose 1.88 (range 0.92-3.16) mg) was administered to rea ch a T4/T1 ratio of 0.5; full recovery to 1.0 was produced in a mean t ime of 25.3 (14-39) min. During recovery from neuromuscular block, we measured tidal volume, forced vital capacity (FVC), forced expiratory volume in 1 s (FEV(1)) negative inspiratory pressure (NIP), peak expir atory flow rate (PEFR), mid-expiratory flow rate (MEFR) and 5-s head l ift. The assessments were started when the train-of-four (TOF) ratio r eached 0.5 +/- 0.001 and repeated at each 0.1 +/- 0.001 increase up to a ratio of 1.0. All volunteers showed ptosis and diplopia after the f irst dose and difficulty in swallowing with subsequent doses. They als o experienced a pleasant, relaxing sedative sensation. All could susta in head lift for 5 s at a TOF ratio of 0.5 and higher, except for one subject who could not lift his head only at a ratio of 0.5. There was a statistically significant decrease in FVC, FEV(1) and PEFR with a no nsignificant decrease in other pulmonary measurements, except for NIP which only decreased significantly at a ratio of 0.5. These changes ar e probably of no clinical importance. All the measured respiratory var iables returned to control values at a TOF ratio of 0.9.