Cognitive impairment following balanced general anesthesia or total intravenous anesthesia in patients over 50 years of age

A Gordillo-Moscoso1, A Lopez-Mireles2, F Romo-Salas2, D Rodriguez-Cruz3, L Guzman-Orta2, JJ Martinez-Piña2, UF Medina-Moreno1, M Pierdant-Perez1. 1Universidad Autonoma de San Luis Potosi, Medicien School, Epidemiology and Public Healt, Mexico, 2Hospital Central Dr IMP, San Luis Potosi, Anestesiology, Mexico, 3Universidad Autonoma de San Luis Potosi, Psychology School, Mexico

Introduction: In the last years, the population pyramid modify itself in favor of an older population. In the medical environment this change implies an increment in older surgical patients, in whom has been reported a greater post-anesthesia cognitive impairment (PACI). The frequencies ranging from 7-50% with differents anesthetic techniques and sets of patients, though these studies present some degree of methodological or technical failure that have not made possible to identify if this anesthetic risk can be avoided by one technique.

Objective: To determine and compare the prevalence of PACI in post-anesthetic patients over 50 years of age who underwent balanced general anesthesia (BGA) or total intravenous anesthesia (TIA).

Material and Methods: With an RCT design, 56 non-cardiac elective surgery patients were included between July 2010 and January 2011 in the Central Hospital “Dr. Ignacio Morones Prieto”, in the city of San Luis Potosi, Mexico. A signed informed consent was obtained prior to the study. Patients were randomized to receive either BGA or TIA. The study protocol was approved by the Ethical Committee of the hospital. A pre-trial concordance test between the psychologists who applied a pre and a 24 hour post anesthetic Neuropsi questionnaire was obtained. Evaluators were blinded to the treatment for the duration of the whole study. Values are expressed as the mean ± the standard deviation. The statistical analysis was performed as proper with a t-Student or U-Mann-Whitney-Wilcoxon at a statistical significance level of p = 0.05.

Results: 28 patients were included for each treatment group (n = 56). Mean age was 66.4±10.9 years, mean educational level was 2.4±4.5 elementary school years and mean hours under anesthesia were 2.5±0.6. There were no basal differences between groups. Statistical significant differences were noted between post-anesthetic scores in the Attention-Concentration variable (p= 0.02), the Memory variable according to the Feggy-Ostrosky Severity and Damage scale pre and post-normalized (p=0.04), and the total score in the Neuropsi questionnaire, as well as in the hemodynamic parameters, all of these measures show a favorable level in patient exposed to TIA.

Conclusions: Our study demonstrates a greater prevalence of post-anesthesia cognitive impairment in post-anesthetic patients over 50 years of age who underwent balanced general anesthesia than in patients who underwent total intravenous anesthesia. The most affected parameters are the Attention-Concentration and Memory variables. TIA seems to be a useful tool to avoid the risk of PACI in patients over 50 years of age, otherwise cognitive impairment could potentially alter the quality of life of these patients and increment the costs of medical, nursing and assistential care.