Association between asymptomatic hypertension and adverse cardiovascular and neurological events after outpatient interventional pain medicine procedures.

Abstract

Introduction Hypertension is a risk factor for major end-organ damage.1 For this reason, guidelines for ambulatory surgery centers require that blood pressure be monitored during procedures. Many pain physicians routinely monitor blood pressure during pain procedures, but it is not known whether they do so out of concern, out of habit, or simply to comply with guidelines. Some physicians cancel procedures if patients present with asymptomatic hypertension on the day of the injection.

The present study was undertaken to investigate whether any empirical evidence could be found to justify concern about hypertension during the performance of pain procedures. The null hypothesis tested was that asymptomatic hypertension constitutes no risk during pain procedures. This hypothesis could be refuted if episodes of adverse events, attributable to hypertension, could be found in a large series of procedures.

Methods After ethics approval was obtained from the University of Pennsylvania, a chart review was performed of consecutive pain procedures performed under local anesthesia at the Tuttleman Surgery Center of the University of Pennsylvania Hospital, between April 1, 2013, and April 1, 2018. The procedures encompassed epidural injections, radiofrequency neurotomies, medial branch blocks, peripheral nerve blocks, and injections into zygapophysial, sacro-iliac, hip, knee, or shoulder joints. Pain procedures performed under sedation were excluded.

The records were searched for evidence of any cardiovascular adverse events during 24 hours after the procedure. For patients with asymptomatic systolic pressure above 210 mm Hg or diastolic pressure above 120 mm Hg, the search for adverse events was extended to cover 7 days after the procedure.

Results During the period of study, 7014 patients underwent 16 667 procedures. The mean pressures of the patients treated were 139 ± 23 mm Hg systolic and 81 ± 14 mm Hg diastolic. The majority of systolic pressures were in the Stage II hypertension category of the American Heart Association. The majority of diastolic pressures were in the normal category. There were 1258 patients with systolic pressure greater than 210 mm Hg or diastolic pressure greater than 120 mm Hg.

No evidence was found of any myocardial infarction, cerebrovascular event, neurological deficit, death, or hospitalization for cardiovascular events within 24 hours of the procedure, nor were there any such events up to 7 days after the procedure in the 1258 patients with severe hypertension.

The only adverse events encountered were 5 instances of vasovagal reaction, 2 instances of self-limited numbness and tingling, 1 episode of being unresponsive for 20 seconds (occurring after the procedure), 1 episode of palpitations, and 1 case of hypertension with chest tightness, which proved uneventful.