Background and Goal of Study: In Chile, almost one million major surgical operations are performed
per year, from minimally invasive to highly complex. Every surgical intervention implies a risk that has associated morbidity and mortality. There are numerous ways to categorize patients into risk groups. One of the most widely used scales in the world is the American Society Anesthesiologist Physical Status Classification System (ASA PS), which allows us to assess the preoperative status of patients. This is used and registered universally by anesthesiologists, generating in a permanent way relevant information, for health professionals and administrators. However, there are no studies that assess the ASA PS scale and its relation to the morbidity and mortality of patients undergoing surgery in our population. This study has Institutional Review approval. The aim of this study was to determine the association between postoperative survival and ASA PS in patients undergoing major surgery in a High Complexity Hospital in Chile, Dr. Hernán Henríquez Aravena Hospital in Temuco (HHHA).

Materials and Methods:Retrospective cohort of patients operated on for major surgery during 2016, at the HHHA. We excluded patients who presented records with incomplete or inconsistent data.
Descriptive and analytical statistics were performed. To assess survival, the Kaplan-Meier method was used.

Results and Discussion:Data from a total of 18,751 surgeries were analyzed. The average agewas 44 years (83.2%&gt; 15 years), with 55.7% female. The average surgical time was 93. 66.7% were elective. 23.2% on an outpatient regimen.The types of anesthesia were 50.6% Inhalational, 27.2% Neuroaxial, 15.2%Regional, 7.1% TIVA. The distribution according to ASA PS was: ASA 1, 23.2%; ASA2, 52.5%; ASA 3, 24.0%; ASA 4, 0.3%. The mortality according to ASA PS was: ASA 1, 2.1%; ASA 2, 5.0%; ASA 3, 11.7%; ASA 4, 43.3%. Overall mortality at 20 months was 6.1%.

Conclusion(s):An association was found between ASA SP classification and mortality, with higher mortality with higher ASA. The ASA SP classification is a good risk estimator for postoperative mortality.The global mortality was 6.1% at 20 months follow-up period 

04 / Association between American Society Anesthesiologist Physical Status classification and postoperative survival in patients subjected with a major surgical intervention in a high-complexity hospital.