British journal of anaesthesia
-
Antagonism of atracurium-induced neuromuscular blockade with neostigmine (one or two doses of 2.5 mg) was compared, using electromyography, with spontaneous recovery. Two levels of blockade were studied, one in which the initial response of the train-of-four has reached 10% of control and the other 50% of control. Adequate recovery was considered to be present when the ratio of the fourth response to the first (train-of-four ratio) had reached 70%. ⋯ This acceleration of recovery after neostigmine was most marked with the greater degree of blockade, but two doses of neostigmine were no more effective than one. Spontaneous recovery to the train-of-four ratio of 70% was slow, in the order of 1 h after an initial dose of 0.5 mg kg-1 and 45 min after incremental doses of 0.2 mg kg-1. It is concluded that antagonism of atracurium with one dose of neostigmine is usually desirable, that two doses are unnecessary, and that spontaneous recovery is slower than is generally realized.
-
Comparative Study
Propofol or thiopentone: effects on intraocular pressure associated with induction of anaesthesia and tracheal intubation (facilitated with suxamethonium).
Changes in intraocular pressure (IOP) were studied in patients given propofol 2.1 mg kg-1 (n = 30) or thiopentone 4.9 mg kg-1 (n = 30) followed by suxamethonium 1.0 mg kg-1 and tracheal intubation. Half the patients in each group received an additional smaller dose of the same induction agent (propofol 1.0 mg kg-1 or thiopentone 2.0 mg kg-1) immediately before intubation. Both agents produced significant decreases in IOP which were slightly more marked with propofol. ⋯ Intubation of the trachea produced the greatest increase in IOP, averaging about 25% above control in all groups except in the group given the additional dose of propofol, in whom IOP remained below control values throughout the process of induction and intubation. Ten patients (33%) experienced pain on injection with propofol. A decrease in systolic arterial pressure of more than 30% was observed in 12 patients (40%) receiving propofol, compared with three (10%) of those given thiopentone.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Antagonism of vecuronium and atracurium: comparison of neostigmine and edrophonium administered at 5% twitch height recovery.
In 39 healthy patients antagonism, by neostigmine 0.07 mg kg-1 or edrophonium 0.8 mg kg-1, of neuromuscular blockade induced by vecuronium or atracurium, was compared. Reversal was attempted when the height of the single twitch (TH) had recovered spontaneously to 5% of the control value. The evoked responses, initially single twitch, then train-of-four (TOF) were observed until the TOF ratio was 70%. ⋯ The time from a TH of 75% to a TOF ratio of 70% was shorter following neostigmine than following edrophonium with both vecuronium (P less than 0.01) and atracurium (P less than 0.01). Edrophonium had a much more variable effect on vecuronium than on atracurium. These results show that although the onset of action of edrophonium was faster than that of neostigmine, this did not lead to a faster clinical recovery, and antagonism by edrophonium may be delayed in a number of patients if vecuronium is the neuromuscular blocker.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Cardiovascular and catecholamine responses to laryngoscopy with and without tracheal intubation.
The catecholamine and cardiovascular responses to laryngoscopy alone have been compared with those following laryngoscopy and intubation in 24 patients allocated randomly to each group. Following induction with fentanyl and thiopentone, atracurium was administered and artificial ventilation undertaken via a face mask for 2 min with 67% nitrous oxide in oxygen. Following laryngoscopy, the vocal cords were visualized for 10 s. ⋯ Arterial pressure, heart rate and plasma noradrenaline and adrenaline concentrations were measured before and after induction and at 1, 3 and 5 min after laryngoscopy. There were significant and similar increases in arterial pressure and circulating catecholamine concentrations following laryngoscopy with or without intubation. Intubation, however, was associated with significant increases in heart rate which did not occur in the laryngoscopy-only group.
-
Randomized Controlled Trial Comparative Study Clinical Trial
Effect of topical lignocaine on the sympathoadrenal responses to tracheal intubation.
The catecholamine and cardiovascular responses to laryngoscopy and tracheal intubation have been studied in 30 patients undergoing elective gynaecological surgery, allocated randomly to one of three groups: group 1 received 4% lignocaine 160 mg using a Forrester Spray; group 2 received 4% lignocaine 160 mg by "Laryng-o-jet"; group 3 received an equal volume of saline administered by Forrester Spray. In all three groups, there were similar and statistically significant increases in mean arterial pressure and plasma adrenaline and noradrenaline concentrations 1 min after intubation, with diminution of these responses by 5 min after intubation. There were no differences between the three groups at any stage, which suggests that topical anaesthesia of the mucosa of the upper airway, as performed conventionally, is ineffective as a means of ameliorating the pressor and catecholamine responses to routine laryngoscopy and intubation.