Ageing, obesity, dyslipidaemia, and hospital-room hypertension are clinical risk factors relating to pre-anaesthesia hypertension

Background
Pre-anaesthesia hypertension (PAH) occurs when the blood pressure (BP) in patients before surgery, in the operating room, before anaesthesia induction, temporally elevates regardless of normal ambulatory recorded BP or self-measured BP at home. PAH might be caused by anxiety and mental stress about the anaesthesia and surgery. We know that most of the patients with sustained hypertension (SH) are elders, males, obese subjects, and dyslipidaemic subjects. Furthermore, most of the patients with white coat hypertension, which is caused by mental stress about the medical environment of an outpatient, clinic, and hospital ward, are elders, females, and non-smokers. In the present study, we investigated some relevant clinical characteristics influencing PAH.

Material and methods
Sampling data on patients more than 20 years old, who underwent consecutive operations under general, intrathecal, or epidural anaesthesia were retrospectively collected from hospital records and anaesthesia records. Hospital-room hypertension (HH) was defined as systolic BP (sBP) greater than or equal to 140 mm Hg in the hospital room before anaesthesia and surgery. Operating-room hypertension (OH) was defined as sBP greater than or equal to 140 mm Hg in the operating room before anaesthesia induction.

Results
112 and 119 patients belonged to the OH and operating-room normotension (ON) groups, respectively. The OH group members were significantly older than the ON group members. Body mass index in the OH group was significantly greater than in the ON group. The proportions of males, dyslipidaemic subjects, and non-smokers in the OH group were significantly higher than in the ON group. In the logistic regression analysis, age, body mass, dyslipidaemia, and HH were selected as significant factors that contribute independently to OH (odds ratios; 1.045, 1.031, 2.912, and 4.354, respectively).

Conclusions
The clinical characteristics of the patients with OH are: elders, obese subjects, dyslipidaemic subjects, and hospital-room hypertensive subjects. Ageing, obesity, dyslipidaemia, and HH are clinical risk factors relating to PAH.