Chu Review: Davis 2023’s review on Hypertensive Emergencies

I absolutely love EB Medicine. My program director in residency introduced us to it during my PGY1 in 2017. It’s chockfull of great issues on core topics that everyone should know in emergency medicine. There are issues like “the back pain issue,” “the asthma issue,” “the PALS update” issue and so on. They’re more up to date than textbooks and have a lot of immediately useable information. Highly recommend getting access to them if you can, either by institution, continuing medical education funding, or otherwise. They can be a bit dense to read (most issues pass the 20 page mark easily), but they have great summaries and practice-changing points in the back. Most also have clinical pathways drawn out, too. If you have a subscription, you can also get CME credits! EB Medicine and Up to Date article reading while on or off shift are some of my main ways to pick up CME credits now that I’m out of residency and post-residency training.

This issue looks at various emergent medical conditions that present with elevated blood pressure. I’ll be honest, it’s frustrating when patient present to the ER (either on their own or sent by an outpatient clinician) purely “because of the number.” Some clinicians don’t even follow their own academy’s guidelines on this! I think every ER doc can unfortunately share in this moment, haha.

Davis, et al. Hypertensive emergencies: guidelines and best-practice recommendations. Emergency medicine practice, 25, 6.
https://www.ebmedicine.net/topics/cardiovascular/emergency-medicine-hypertensive-emergencies

One Liner: It is the presence of end organ damage which mandates immediate treatment, as opposed to just a patient w hypertension; will not change my practice, but is a good reminder

Brief Summary:

• You must be able to distinguish between “a patient with HTN” from “a patient with an actual hypertensive emergency” through the absence or presence of EOD. Pts w true HTN emergency have higher mortality and rates of requiring kidney transplants.
• Different societies and guidelines exist regarding thresholds of BP definition and management, and there are low amounts of good evidence (except in mgmt of ICH) but a general recommendation is BP > 180/110 mmHg should be evaluated promptly to see if they have signs of EOD.
• HTN emergencies more likely in > 60 yo, Black, male, uninsured, low SES, often from deranged autoregulation and dysregulation in multiple systems, including endocrine (i.e. RAAS), neuro, cardiovascular, renal. Every organ system can manifest a symptoms in the presence of hypertension (e.g. aortic dissection, HTN encephalopathy, SAH, PRES, Cushing syndrome, sclerodermal renal crisis, pre-eclampsia, toxidromes and medication side effects, etc.)
• The most common symptoms in HTN emergency include SOB, CP, HA, AMS, focal neuro deficits. Most common sequelae include pulmonary edema, heart failure, ischemic stroke, ACS, hemorrhagic stroke, aortic syndromes, encephalopathy.
• The Italian “BARKH” mnemonic can serve as a reminder, Brain, (stroke, encephalopathy), Arteries (aorta, pre/eclampsia, HELLP), Retina, Kidney (renal insuffiency, TTP-HUS), Heart (failure failure, pulmonary edema).
• Labs can include POC glucore, renal function, electrolytes, cardiac markers, CBC (can check for anemia, plt count abnormalities of TTP-HUS, anemia chronic disease, DIC, others).
• ECGs can show ischemia or strain pattern, including: ST depression w down-sloping convex ST segment and disconfordant T wave inversions in the lateral precordial leads, increased R wave amplitude in left sided ECG leads (I, aVL, V4-V6), increased S wave depth in right sided leads (III, aVR, V1-3).
• Imaging should be tailored to clinical concrens and symptoms. Note concerns of CT Brain within 6 hr for SAH, lumbar puncture, MRI may be needed for PRES. Ultrasound can check for papilledema as well.
• Treatments are predicated on signs, symptoms, and syndrome. Acute Heart failure (NIPPV, vasodilators such as nitrates, and diuresis, avoid morphine), Acute Ischemic Stroke (thrombolysis and thrombectomy get to < 180/110 mmHg, otherwise < 220/120), ACS (incl STEMI, NSTEMI, unstable angina; avoid beta blockers in high risk pts eg sysBP < 120 mmHg, age > 70, HR > 110 bpm due to higher mortality; nitrates may be useful but lack mortality benefit), ICH (drop sysBP < 140 mmHg and keep between 130-150 mmHg to lwoer mortality, limit hematoma expansion, lower rates of neuro deterioration), SAH (prevent rebleeding, poor data but general rec sysBP < 160-180 mmHg, other societies tx if MAP > 110), Aortic Dissection (first get HR to 60, then BP < 120 mmHg), HTN encephalopathy (often in BP > 220/120 mmHg, drop MAT 20-25%, see if there may be Rx like immunosuppressant, autoimmunity, renal failure), Pre-Eclampsia and Eclampsia (severe: BP > 160/110 mmHg, or 140/90 w thrombocytopenia, impaired liver function, renal insufficiency, pulm edema, new onset HA, or visual change; ACOG rec labetalol, hydralazine, PO nifedipine; magnesium 4-6 g IV load and 1-2 g/hr), Acute Renal Failure (no consensus or RCT’s)
• No specific data on when exactly to start an arterial line due to paucity of studies and proven benefit.
• Beta blockers in cocaine classical teaching, but may be overstated.
• Typical Rx used in HTN emergencies include enalaprilat (ACEi, 1.25-5 mg IV, risk of hyperkalemia, cough), esmolol (load 1 mg/kg, esp for aortic dissection), labetalol (BB and alpha blocker 20 mg IV), clevidipine (CCB 1-2 mg/hr, reflex tachycardia), nicardipine (CCB 5 mg/hr IV, reflex tachycardia), magnesium (CCB, vasodilator, antidysrhythmic, 4-6 g IV over 20-30 min, drip 1-2 g/hr, respiratory depression), hydralazine (direct arterial relaxer, 5-20 mg IV), nitroglycerin (0.5 mcg/min IV drip, HA, flushing), sodium nitroprusside (vasodilator< NO releaser, 0.5 mcg/kg/min IV, cyanide tox).