By Ed Sutton, MD
In 2017, the American Heart Association (AHA) and the American College of Cardiology (ACC) published new guidelines for diagnosing and treating high blood pressure. Initial recommendations continue to be lifestyle and diet changes for the “elevated” category; this change probably will not affect anesthesia providers. What we are challenged with on a far too frequent basis are patients presenting in the “hypertensive crises” categories, with systolic BP > 180mm Hg and diastolic BP > 120mg Hg. Become familiar with each of the new categories.
When encountering a patient thought to be in a hypertensive crisis category, find a properly fitted sphygmometer and perform a true auscultated BP check. Commonly used oscillometric technique non-invasive blood pressure (NIBP) cuffs DO NOT measure systolic and diastolic pressures. NIBPs simply assign the point of maximal oscillations as the MAP and then calculate a systolic and diastolic pressure based on proprietary algorithms. For the engineering inclined, a link is included here for explanation. The discussion and conclusions are worth the read.
If you feel the reported blood pressures are accurate, consult with patient’s Gastroenterologist to formulate a plan for best management to avoid a bad cardiovascular outcome. Anxiety aside, blood pressures this high in a patient without a diagnosis of hypertension should be a hard stop that warrants further workup. In a previously diagnosed patient who may have skipped a dose of their antihypertensive medication because of NPO instructions or poor compliance, consider a trial of IV medication after consultation with their Gastroenterologist. We can often get the patient’s BP into an acceptable range very easily; if not, it shows that we’ve tried to provide the best care for the patient.
Many of our centers perform GI and anesthesia care for end-stage renal disease (ESRD) patients who require dialysis . The ASA has recognized that ESRD patients undergoing regularly scheduled dialysis and unburdened by other comorbidities can be given an ASA physical status of 3. Many of our presenting ESRD patients have existing comorbidities that create a persistent threat to life, which makes them an ASA 4. Drawing on Medicare national data banks, the ASA has revealed that almost 56% of patients initiating dialysis will die within the first year.
Anecdotal reports of dialysis patients in GI centers that have had poor outcomes describe what sounds like a Vasoplegia type syndrome, with very poor response to normal doses of vasopressors. Is this a response to hypercarbia and a secondary worsening of any preexisting metabolic acidosis? Maybe. That’s why I continue to recommend taking Propofol deep sedation off the table with these patients. The majority of patients will do very well with moderate sedation, with very few patients requiring judicious use of small doses of Propofol with Versed/Fentanyl.
In the Vasoplegia syndrome, Vasopressin needs to be given early as it tends to still work in acidotic environments and will potentiate other vasopressors. This may give you time to address any acid-base issues so other catecholamines will function normally. When sedating dialysis patients, have the drug in the room, familiarize yourself with the bolus resuscitation dosage (0.5-1 unit), and have a plan for proper dilution to deliver your desired dosage. I highly recommend the following article for a comprehensive review of the Vasoplegic Syndrome – view here.
