Effects of general anaesthesia on the intraocular pressure in man. Comparison of tubocurarine and pancuronium in nitrous oxide and oxygen.

The introduction of new anaesthetic drugs demands that their action should be compared with that of already established agents. Pancuronium bromide was introduced into clinical anaesthetic practice by Baird and Reid (I967), and has since achieved widespread acceptance because it is reputed to have fewer cardiovascular side-effects than other non-depolarizing relaxants (Baird, I968; Sellick, 1970; McDowall and Clarke, I969; Stoelting, I972; Feldman, 1973; Nightingale and Bush, I973). Its effect on the intraocular pressure (IOP) has not previously been described except in a paper by Stankovic, Driucic, and Prokic (I97,) who reported on its use in combination with halothane, and with nitrous oxide and halothane. However, since halothane has been shown to have marked effects on the IOP (Magora and Collins, I96I; Mehta, I962; Wagenaar and Van der Wal, I964; Esposito, I965), the present study was designed in such a way as to exclude other possible causes of change in the IOP by concurrently used agents and to compare the effects of pancuronium with those of tubocurarine under standard conditions. The IOP was measured by a Perkins hand-held tonometer that can be used irrespective of the position of the patient (Perkins, I965). This instrument was chosen because it uses the principle of applanation which is more accurate than indentation tonometry with the Schi6tz tonometer used in previous studies (Taylor, Mulcahy, and Nightingale, 1968).