The association between nondipper pattern and perioperative hypertension in patients with controlled hypertension

Perioperative hypertension is a frequent complication even in preoperatively normotensive or controlled hypertensive patients and there is a lack of data regarding the effect of nondipping pattern on perioperative hypertension.

In this study, we aimed to investigate the possible effect of nondipping blood pressure pattern on the risk of perioperative hypertension.

234 hypertensive patients who underwent surgery with general anesthesia were evaluated prospectively. The study enrolled patients with well-controlled preoperative blood pressure. The 24-h ambulatory blood pressure monitoring results were used to classify patients as dippers and nondippers. Perioperative hypertension is defined as a systolic/diastolic arterial blood pressure greater than or equal to 160/90 mmHg or systolic blood pressure elevated by more than 20% from the patient's baseline level for more than 15 min perioperatively.

There were 61 (26%) nondipper patients [mean age: 62.1 ± 7.1 years, 25 (40.9%) men] and 173 (74%) dipper patients [mean age: 61.4 ± 8.1 years, 83 (47.9%) men]. In the nondipper group, perioperative hypertension was observed in 31 (51.3%) patients, whereas in the dipper group, 33 (19.3%) patients experienced a hypertensive attack (P < 0.001). The independent predictors of perioperative hypertension were the presence of the nondipping pattern [odds ratio (OR) 3.084; 95% confidence interval (CI) 1.831-5.195; P < 0.001], the presence of diabetes mellitus (OR 2.059; 95% CI 1.215-3.490; P = 0.007), and the number of drugs (OR 2.317; 95% CI 1.102-5.097; P = 0.027).

The frequency of perioperative hypertension was higher in preoperative normotensive and known hypertensive patients who were identified as nondippers. In addition, diabetes mellitus and number of drugs were found to be predictors of perioperative hypertension.