Relationship among Preoperative, Pre and Postinduction Blood Pressure in Normotensive and Hypertensive Patients

Bernardis Ricardo Caio Gracco De,Siaulys Mônica Maria,Vitoreli Marcel Veronez,Izquierdo Jesse Abimael Infante,Souza Helena Knebel Vieira De,Silva Mauro Prado Da,Pinheiro Pedro Ferretti,Yamamura Silvio Julio Bittencourt,Mathias Ligia Andrade Da Silva Telles

doi:10.36959/377/346

Abstract

Abstract Objectives: This study aimed to verify the relationship between blood pressure (BP) obtained during preoperative evaluation at preinduction and compared to BP at 20 min after induction for normotensive and hypertensive patients. Methods: Data from patients who underwent elective surgical procedures from July 2018 to September 2019 were retrospectively extracted and analyzed. The data included patient characteristics (age, sex, weight, height, body mass index (BMI)), physical status (ASA classification), comorbidities, medications in use, and mean arterial BP (MAP) recorded preoperatively (MAPpre-op), before induction of anesthesia (MAPpre-ind), and 20 min after induction (MAPpost-ind). Results: A total of 1026 patients were selected, 341 were included in the final analysis (normotensive patients (GNT n = 203), treated hypertensive patients (GTREAT n = 98), untreated hypertensive patients (GNO TREAT n = 40). There was an increase in the median MAP from preoperation to preinduction in the total sample and the three groups (GNT, GTREAT, and GNO TREAT). There was a statistically significant reduction in MAPpost-ind concerning MAPpre-ind and MAPpre-op in the three groups. The three groups' comparison showed a statistically significant difference between MAPpost-ind and MAPpre-ind and between MAPpost-ind and MAPpre-op. Conclusions: Our study showed that normotensive and hypertensive patients showed a significant BP increase at the preinduction time point. Treated and untreated hypertensive patients had a more considerable increase in preinduction BP and BP reduction at 20 min after anesthesia induction than normotensive patients. These changes were more significant in hypertensive patients without treatment.

Highlights

Changes in intraoperative blood pressure (BP) are frequent, especially hypotension, during noncardiac and cardiac surgery with general anesthesia
There is no consensus regarding whether intraoperative hypotension (IOH) should be considered when the patient has a BP below a threshold value or presents a reduction in baseline BP values, neither there is a consensus been reached regarding the specific importance of postinduction hypotension, which is estimated to occur at up to 20 min after induction (BPpost-ind) [5,6,12,13,14,15,16,17,18,19,20,21]
Patients were eligible for 18 years of age or older; were American Society of Anesthesiologists (ASA) class I, II or III; had preinduction and intraoperative BPs measured in the supine position and had undergone elective surgery under general anesthesia