Aminophylline and Cognitive Function After Sevoflurane Anaesthesia
Status:
Completed
Trial end date:
2010-08-01
Target enrollment:
Participant gender:
Summary
Early postoperative recovery of neurologic and cognitive functions is especially advantageous
after fast-tracking ambulatory procedures to hasten home discharge after surgery.1 It is well
known that volatile anaesthetic agents may generate adverse postoperative cognitive effects
and even traces of it may affect task performance in healthy volunteers.2Hence, rapid
elimination of the volatile anaesthetics may help reduce postoperative confusion and
cognitive impairment in surgical patients by facilitating a faster recovery from general
anaesthesia.3 Sevoflurane has been advocated for the routine anesthesia for ambulatory
surgery patients. It activates adenosine A1 receptors in primary rat hippocampal cultures
through the liberation of adenosine secondary to the interaction of with adenosine transport
or key enzymes in adenosine metabolism.4 However; sevoflurane anaesthesia is associated with
slower emergence and delayed early postoperative cognitive recovery than desflurane5 and
xenon2 anaesthesia.
Aminophylline, which is a hydrophilic cyclic adenosine mono-phosphate (cAMP) dependent
phosphodiesterase inhibitor has been used for long time to antagonize the sedative effects of
morphine, diazepam, and barbiturates.6-7Aminophylline in doses of 2-5 mg/kg shortens the
recovery from sevoflurane anaesthesia and improves bispectral index scores (BIS) with
concurrent increases in heart rate which might have a detrimental effect in patients with
ischaemic heart disease.8-11However, the use of smaller doses of 2-3 mg/kg is associated with
less increases in heart rate. 10-11 The use of 1 mg/kg of Doxapram is comparable to 2 mg/kg
of aminophylline in improvement of early recovery from sevoflurane anaesthesia secondary to
its central nervous system stimulating effect rather than increased ventilatory elimination
of sevoflurane.11 Currently, there is no available published studies have investigated the
effects of either theophylline or doxapram on early postoperative cognitive recovery after
balanced anaesthesia with sevoflurane.
We hypothesized that the use of small doses of aminophylline [2-3 mg/kg] may be comparable to
larger doses in improvement of the early postoperative cognitive recovery from sevoflurane
anaesthesia with associated non-significant increases in heart rate.
The present study investigated the effects of 1 mg/kg of doxapram, and 2, 3, 4, and 5 mg/kg
of aminophylline on the early postoperative cognitive recovery using the Short Orientation
Memory Concentration Test (SOMCT), response entropy (RE) state entropy (SE), difference
between RE and SE (RE-SE), end-tidal sevoflurane concentration, haemodynamics, the times to
eyes opening and to extubation and degree of sedation after sevoflurane anaesthesia in
patients undergoing ambulatory surgery.