Hypertension and intra‐operative incidents: a multicentre study of 125 000 surgical procedures in Swiss hospitals*

Abstract

It is debated whether chronic hypertension increases the risk of cardiovascular incidents during anaesthesia. We studied all elective surgical operations performed in adults under general or regional anaesthesia between 2000 and 2004, in 24 hospitals collecting computerised clinical data on all anaesthetics since 1996. The focus was on cardiovascular incidents, though other anaesthesia-related incidents were also evaluated. Among 124,939 interventions, 27,881 (22%) were performed in hypertensive patients. At least one cardiovascular incident occurred in 7549 interventions (6% (95% CI 5.9-6.2%)). The average adjusted odds ratio of cardiovascular risk for chronic hypertension was 1.38 (95% CI 1.27-1.49). However, across hospitals, adjusted odd ratios varied from 0.41 up to 2.25. Hypertension did not increase the risk of other incidents. Hypertensive patients are still at risk of intra-operative cardiovascular incidents, while risk heterogeneity across hospitals, despite taking account of casemix and hospital characteristics, suggests variations in anaesthetic practices.

The occurrence of intra‐operative hypotension varies between hospitals: observational analysis of more than 147,000 anaesthesia

“…Regarding the secondary endpoints, the same kinds of analyses were performed. However, to assess the impact of intra-operative hypotension on post-operative incidents, we considered, like in a previous report focusing on chronic hypertension, 41 the interaction between hypotension and the indicator variables for the hospitals. This procedure allowed the impact of hypotension to be heterogeneous across hospitals.…”

Evolution of anaesthesia care and related events between 1996 and 2010 in Switzerland

“…Although some routine data collection systems exist in other countries, they differ widely in their coverage and face the same difficulties as ADS in reaching universal participation. Indeed, some systems are restricted to one hospital, while others extend nationwide, such as those in France, Denmark and Germany. Because involvement in the national systems is mostly voluntary, the proportions of participating hospitals are much less than 100%, but better than in Switzerland.…”

“…Another major challenge would be to obtain information on main surgical outcomes by following patients, e.g., at 30 days, and to link this information to recorded patient characteristics and adverse events. Furthermore, ADS consisted of an extremely large pool of data that could be used to answer specific research questions, e.g., regarding related events …”

“…In the present study, we used only the variables collected through the MDS or the QM (Table ). An event was defined as ‘a particular event requiring one or more measures taken to avoid further deterioration or to treat a situation currently or potentially serious’ . For the purpose of this study, we focused only on intraoperative events (IAEs); ‘intraoperative’ described the time frame between arrival in the operating room and the patient's release from it.…”

The Effect of Intubation with Video and Conventional Laryngoscopy on Hemodynamic Response

“…During laryngoscopy and ET, airway stimulation results in reflex sympathetic system activation and unfavorable hemodynamic responses such as tachycardia, blood pressure increase and arrhythmia [2] . Among these hemodynamic responses, hypertension (HT) and tachycardia are the important determinants of cardiac morbidity in the perioperative period [3] . In particular, tachycardia leads to more excessive load on the heart than blood pressure increase and may result in intraoperative myocardial ischemia [4] .…”