EFFECT OF PRIMING DOSE OF VECURONIUM ON LUNG-FUNCTION IN ELDERLY PATIENTS

We questioned whether the side effects outweighed the advantages of pr iming doses of nondepolarizing neuromuscular relaxants in awake patien ts. We have assessed lung function and clinical evidence of muscle wea kness in 10 elderly patients, eight women and two men, aged 67-78 yr, ASA grade I or II, before and 3 min after a priming dose (0.01 mg/kg) of vecuronium. Forced vital capacity (FVC), forced expiratory volume i n 1 s (FEV1), maximum midexpiratory flow rate (MMEF), peak expiratory flow rate (PEFR), inspiratory capacity (IC), functional residual capac ity (FRC), expiratory reserve volume (ERV), residual volume (RV), slow vital capacity (SVC), and total lung capacity (TLC) were measured by using a Morgan transfer test machine and oxygen saturation (SpO2) was measured by pulse oximetery. All the patients developed ptosis, six ha d diplopia and were unable to perform the Valsalva maneuver for 10 s, and four were unable to swallow or lift their head for >4 s, demonstra ting significant muscle weakness. Significant reductions occurred in F VC, FEV1, FRC, ERV, SVC, and TLC. SpO2 decreased in 8 of 10 patients, and in 4 the decrease exceeded 4%. We conclude that priming with vecur onium 0.01 mg/kg in elderly patients causes significant impairment of lung function and a significant decrease in oxygen saturation.