Deciphering the explanatory potential of blood pressure variables on post-operative length of stay through hierarchical clustering: A retrospective monocentric study

Objective: Mean arterial pressure is widely used as the variable to monitor during anesthesia. But there are many other variables proposed to define intraoperative arterial hypotension. The goal of the present study was to search arterial pressure variables linked with prolonged postoperative length of stay (pLOS).
Design: Retrospective cohort study of adult patients having received general  for a scheduled non cardiac surgical procedure between 15th July 2017 and 31st December 2019.
Methods: pLOS was defined as a stay longer than the median (main outcome), adjusted for surgery type and duration. 330 arterial pressure variables were analyzed and organized through a clustering approach. An unsupervised hierarchical aggregation method for optimal cluster determination, employing Kendall’s tau coefficients and a penalized Bayes information criterion was used. Variables were ranked using the absolute standardized mean distance (aSMD) to measure their effect on pLOS. Finally, after multivari..., Patient characteristics and preoperative medications were collected from Cesare™, a computerized software for preoperative anesthetic evaluation (Bow Médical, 80440 Boves, France). Centricity Anesthesia software was used to collect intraoperative variables (GE Healthcare, 78 530 Buc, France). lenght of stay and in-hospital mortality were obtained by questioning the health data warehouse., , # Deciphering the explanatory potential of blood pressure variables on post-operative length of stay through hierarchical clustering: A retrospective monocentric study

[https://doi.org/10.5061/dryad.12jm63z5r](https://doi.org/10.5061/dryad.12jm63z5r)

#### Demography.csv (on Zenodo)

Demography table contains main patients' characteristics. 10 variables

| id\_data | Patient number |
| :------------- | :---------------------------------------------------------------------------------- |
| surgery | 1: general; 2: lung; 3:neurosurgery; 4: urology; 5: vascular; 6: gynecology; 7: ENT |
| age | 1: below 65 years; 2: 65 years and more |
| sex | 1:M; 2: F |
| los | Length of post-operative stay (days) |
| time\_quart...