Effect of aminophylline or physostigmine on recovery from nitrous oxide-enflurane anaesthesia

Adjunctive use of physostigmine salicylate (Anticholium®) in perioperative sepsis and septic shock: study protocol for a randomized, double-blind, placebo-controlled, monocentric trial (Anticholium® per Se)

Background

Severe sepsis and septic shock remain a major challenge, even in modern intensive care. In Germany, about 68,000 patients die annually because of septic diseases, characterized by a complex systemic inflammatory response. Causal treatment of the underlying infection is essential for successful management of sepsis, but the course can be positively influenced by supportive and adjuvant measures. The cholinergic anti-inflammatory pathway (CAP) represents a new approach to adjunctive therapy of septic diseases and can be pharmacologically activated by the acetylcholinesterase inhibitor physostigmine (Anticholium®). Promising effects can be found in several in vitro and in vivo models of sepsis, such as a reduction in pro-inflammatory cytokines and improved survival.

Methods

Anticholium® per Se is a randomized, double-blind, placebo-controlled, monocentric trial to assess whether the CAP can be transferred from bench to bedside. In this pilot study, 20 patients with perioperative sepsis and septic shock as a result of intra-abdominal infection are enrolled. According to randomization, participants are treated with physostigmine salicylate (verum group) or 0.9% sodium chloride (placebo group) for up to 5 days. The mean Sequential Organ Failure Assessment (SOFA) score during treatment and subsequent intensive care of up to 14 days is used as surrogate outcome (primary endpoint). Secondary outcome measures include 30- and 90-day mortality. An embedded pharmacokinetics and pharmacodynamics study investigates plasma concentrations of physostigmine and its metabolite eseroline. Further analyses will contribute to our understanding of the role of various cytokines in the pathophysiology of human sepsis. A computer-generated list is used for block randomization.

Discussion

This randomized, controlled, monocentric trial investigates for the first time the adjunctive use of physostigmine (Anticholium®) in patients with perioperative sepsis and septic shock and may be a pivotal step toward the clinical use in this indication.

Trial registration

EudraCT Number: 2012-001650-26 (entered 14 August 2012), ClinicalTrials.gov identifier: NCT03013322 (registered on 1 Jan 2017).

Electronic supplementary material

The online version of this article (doi:10.1186/s13063-017-2231-x) contains supplementary material, which is available to authorized users.

Effects of aminophylline on cognitive recovery after sevoflurane anesthesia

PURPOSE

Aminophylline accelerates the recovery from sevoflurane anesthesia. We studied the effects of escalating doses of aminophylline on cognitive and clinical recovery after sevoflurane anesthesia.

METHODS

After ethical approval and informed consent, 150 patients scheduled for elective surgery under sevoflurane-fentanyl anesthesia were randomly allocated to receive saline or 2, 3, 4 or 5 mg/kg of aminophylline (n = 30 for each) at the end of anesthesia (T (0)). Short Orientation Memory Concentration Test (SOMCT) scores, entropy values, end-tidal sevoflurane concentrations (EtSevo), times to eyes opening and extubation, respiratory rate (RR) and tidal volume (TV) were recorded.

RESULTS

Compared to placebo, patients receiving 2, 3, 4 and 5 mg/kg of aminophylline had higher SOMCT scores [median (25th percentile/75th percentile) 20.6 (19/23), 21.5 (21/22), 24.5 (24-25), 25.5 (25/26), respectively, vs. 13.5 (13/14) at 30 min after extubation, and 24 (22/26), 25 (24/26), 27.5 (27-28), 27.5 (27/28), respectively, vs. 18.5 (18/19) at 45 min after extubation], higher entropy values for the first 10 min after T (0), lower EtSevo for the first 4 min after T (0), shorter times to eyes opening [5 (4.0/6.0), 5 (4.0/6.0), 4 (2.0/5.5), and 4 (2.0/6.0), respectively, vs. 9.8 (8.0/11.0) min], shorter times to extubation, shorter times to home discharge (P < 0.001), and higher RR and larger TV values. Patients who received 4 and 5 mg/kg of aminophylline showed higher SOMCT scores, 6 min shorter times to eyes opening and to extubation, and 58 min shorter times to home discharge.

CONCLUSION

The administration of escalating doses of aminophylline accelerates postoperative cognitive recovery from sevoflurane anesthesia, as measured by the SOMCT, due to increased ventilatory elimination of sevoflurane.

The effects of aminophylline on bispectral index during inhalational and total intravenous anaesthesia

Aminophylline is usually used during anaesthesia to treat bronchospasm but recent findings suggest that it can also be used to shorten recovery time after general anaesthesia. However, it is unclear whether aminophylline shows similar properties during a steady-state phase of deep surgical anaesthesia. We therefore wanted to test the hypothesis that the administration of aminophylline leads to an increase in bispectral index as a surrogate parameter suggesting a lighter plane of anaesthesia. The study was designed as a double-blind, randomised, controlled trial with two main groups (aminophylline and placebo) and two subgroups (sevoflurane and propofol). We studied 60 patients. The injection of aminophylline 3 mg x kg(-1) was associated with significant increases in bispectral index up to 10 min after its injection, while heart rate and blood pressure did not change. It appears that aminophylline has the ability to partially antagonise the sedative effects of general anaesthetics.

Drug interactions with inhalational anaesthetics

The literature concerning the interactions between volatile anaesthetics, nitrous oxide and other compounds is reviewed. The majority are well known and most can be managed by careful dosage of the anaesthetics. The following interactions should be stressed since these are less predictable or potentially fatal. Of the cardiovascular drugs mainly the Ca++ channel blockers require attention. The volatile anaesthetics act synergistically with these drugs on the inhibition of cardiac conduction and may induce cardiac arrest. Aminoglycoside therapy should prompt an alternative to enflurane because of increased nephrotoxicity with this combination. Thiopentone induction makes the dog heart more susceptible to arrhythmias, especially during anaesthesia with volatile anaesthetics. Probably pentobarbitone, etomidate or a benzodiazepine should be preferred as an alternative to thiopentone when the use of adrenergic drugs peroperatively is anticipated. Nitrous oxide augments the sequelae after coronary air emboli and impaired cerebral perfusion in animals. The necessity of this drug should therefore be considered when anaesthetizing patients undergoing open heart surgery and patients with severe carotid or cerebral arteriosclerosis.