Bilateral sphenopalatine ganglion block reduces blood pressure and blood pressure variability in never treated patients with essential hypertension

Abstract

Abstract Background Sphenopalatine ganglion (SPG) area is connected through sympathetic fibers with the central nervous system. It is already known that SPG infiltration by lidocaine reduced blood pressure in naïve hypertensive patients. Blood pressure variability (BPV) has been associated with an increased risk of cardiovascular events and mortality, independently of elevated BP levels. We aimed to study the effect of SPG block in BPV in never treated patients with stage I–II essential hypertension. Methods We performed bilateral SPG block with lidocaine 2% in 47 newly diagnosed and never treated hypertensive patients (study group, mean age 50±12 years, 31 men) and a sham operation with water for injection in 11 patients (control group, mean age 51±12 years, 8 men). All patients have been subjected to 24 hour ambulatory blood pressure monitoring (ABPM) prior and a month after the SPG block in order to estimate any differences in BP parameters derived from ABPM (BP, BPV). We defined as responders to SBG block those patients with a 24h average SBP decrease >5 mmHg. Results We noticed the following significant differences in the study group: a. 24h average DBP and daytime DBP were reduced by 1.6±5 mmHg (p=0.04) and 1.9±5 mmHg (p=0.01) respectively and b. systolic BPV during daytime (11±2 mmHg vs. 10±2 mmHg, p<0.05). Interestingly, in the responders group (14/47, 30%, 9 men, age = 47±8 mmHg) and a month after SPG block we noticed that: a. 24h average, daytime, night-time SBP and 24h average, daytime, night-time DBP were reduced by 9±4 mmHg (p<0.001), 9±3 mmHg (p<0.001), 7±7 mmHg (p=0.002) and 6.5±3 mmHg (p<0.001), 6.5±3 mmHg (p<0.001), 4±7 mmHg (p=0.02), respectively and b. systolic BPV during daytime (13±2 mmHg vs. 9±2 mmHg, p=0.01). No differences regarding BPV were found in the non-responders and the sham operation group. Conclusions SPG block is a promising, minimally invasive option of significant BP and BPV decrease in never treated hypertensive patients, especially during daytime activities when SNS is activated. It acts probably through SNS modulation. Since its effect is only anesthetic and non-permanent, SPG block might permit the selection of the hypertensive patients with an activated SNS before any other invasive antihypertensive procedure. SPG block reduces BP variability Funding Acknowledgement Type of funding source: None