A presentation about hypertension and anesthesia for hypertensive patients.

1. SYSTEMIC
HYPERTENSION
AND ANESTHESIA

2. “
Systemic hypertension is diagnosed when:
Systolic BP is consistently ≥130 mm Hg
and/or
Diastolic BP is consistently ≥ 80 mm Hg

3. CLASSIFICATION
Category Systolic BP Diastolic BP
Pre-hypertension 120 – 139 80 – 89
AHA Stage I 130 – 139 80 – 89
Mild 140 – 159 90 – 99
AHA Stage II Moderate ≥ 160 ≥ 100
Severe ≥ 180 ≥ 120
Hypertensive urgency Severe HTN without EOD
Hypertensive emergency Severe HTN with EOD

4. CAUSES
Essential Endocrine Renal Neurogenic Miscellaneous
Idiopathic
>90% of cases
• PIH / Pre-eclampsia
• Estrogen therapy
• Pheochromocytoma
• Thyrotoxicosis
• Acromegaly
• Cushing’s syndrome
• Hyperaldosteronism
• Chronic kidney
disease
• Renovascular
stenosis
• Polycystic
kidney disease
• Anxiety
• Raised ICP
• Autonomic
hyper-reflexia
• Obesity
• Hypercalcemia
• Acute intermitent
porphyria
• Toxins (cocaine)
• Drug withdrawal

5. COMPLICATIONS
EOD (end-organ dysfunction)
× CNS – hypertensive encephalopathy, stroke, ICH, seizures
× CVS – acute MI, LVF, aortic dissection
× Renal – hypertensive nephropathy
× Eyes – hypertensive retinopathy, vitreous hemorrhage
× Other – peripheral vascular disease
Dysautonomia
× “Alpine Anesthesia” – labile BP intra-operatively
× Sympathetic over-activity is seen in some and might show
an exaggerated response to vasopressors/vasodilators

6. PATHOPHYSIOLOGY
× Abnormal baseline elevation of CO, SVR or both
× Evolving pattern over the course CO returns to normal
(i.e. ↓ IV volume), but SVR remains high
× ↑ afterload chronically causes concentric LVH and
diastolic dysfunction
× Altered cerebral auto-regulation i.e. the range of CPP is ↑
× Vascular smooth muscle hypertrophy (↑ arteriolar tone)
and sclerosis (non-compliant vessels)
× Endothelial injury and atherosclerosis
× ↑ intravascular sodium/calcium concentrations

7. LONG TERM THERAPY
Mild HTN may require monotherapy:
× ACEI / ARB (first choice), CCB, Beta Blocker, Alpha-2 Agonist
Moderate / Severe HTN require combination of drugs
× Prior MI patients should receive ACEI / ARB + Beta Blocker +/-
Nitrate to improve outcomes
× CHF, consider adding diuretic (Thiazide, Furosemide)
× CKD, consider replacing ACEI / ARB
× ACEI / ARB may cause post-induction hypotension
× ACEI / ARB contraindicated in renovascular stenosis
× Acute withdrawal may cause rebound HTN (esp. BB, A2 agonist)

8. PRE-OP

9. PRE-OP MANAGEMENT
Evaluate
× Find out cause: Essential (primary) or Secondary
× If no cause, rule out anxiety and drug withdrawal
× Determine chronicity
× Establish the grade: mild, moderate, severe
× Establish the EOD (next slide)
× Determine treatment taken and its control

10. PRE-OP MANAGEMENT
Question
× Chest pain characteristics
× Shortness of breath
× Exercise tolerance / functional capacity
× Orthopnea and dependent edema
× Postural hypotension and light-headedness
× Episodic visual disturbances
× Intermittent claudication

11. PRE-OP MANAGEMENT
Physical exam
× Pulse rate, rhythm and volume
× Heart sounds ( S3  CHF / S4  LVH / murmur )
× Pulmonary rales? ( CHF )
× BP in supine and standing positions
× Carotid bruits?
× Peripheral edema? ( CHF )

12. PRE-OP MANAGEMENT
Investigations
× 12 lead ECG
× Chest X-ray ( if CHF suggestive )
× 2D Echocardiography ( if exercise intolerance, CHF,
murmur, suggestive ECG )
× RFTs ( if uncontrolled HTN )
× S/Electrolytes ( if renal cause, or digoxin/diuretics use )
× Carotid doppler ( if carotid bruit or history of TIA )
× Fundoscopy

13. PRE-OP MANAGEMENT
Preparation
× Avoid longer than necessary NPO time
× Controversial: some departmental policies advise ACEI /
ARB and diuretics should be held on day of surgery, but
this should be individualized
× Start maintenance fluid where possible
× Secure a wide bore IV line for fluid resuscitation
× Secure another IV line for vasopressor/vasodilator
infusions
× Consider good pre-medication with anxiolytics where
possible

14. INTRA-OP

15. INTRA-OP MANAGEMENT
Objectives
× Maintain CPP and RBF – higher than normal MAP will be
needed
× Arterial BP should be kept within 20% of pre-op levels
× Prevent tachycardia – as it can precipitate MI or LVF

16. INTRA-OP MANAGEMENT
Monitoring
× Mandatory: pulse oximetry, NIBP, ECG ( lead II +/- V5 )
× IBPM reserved for patients with severe HTN, labile BP,
refractory hypotension, CHF, and special surgical
procedures
× UOPM reserved for pre-existing renal disease, surgery
expected to last more than 2 hours, or major fluid shifts
× Monitor for pulmonary congestion with oximetry, pre-
cordial stethoscope, POCUS, roentgenogram, PAC, TEE
× BIS monitoring is helpful and should be considered

17. INTRA-OP MANAGEMENT
Induction
× Many display a hypotensive response to induction (likely
due to volume depletion) of anesthesia followed by an
exaggerated hypertensive response to intubation
× Avoid long-acting sympatholytics as they attenuate
normal circulatory reflexes (reducing sympathetic tone +
unmasking vagal tone in a volume depleted patient can
lead to refractory hypotension due to blocked reflex
tachycardia response).
× Give incremental boluses of Propofol and judge the
response with 1 minute interval BP measurements.
× Consider co-induction with Propofol and Ketamine.

18. INTRA-OP MANAGEMENT
Intubation
Following techniques may be used to attenuate the
hypertensive response:
× Deepening anesthesia with potent volatile anesthetic
× Administering bolus of propofol just prior to intubation
× Administering bolus of opioid (i.e. fentanyl)
× Administering IV Lidocaine 1.5 mg/kg
× Achieving beta-blockade with Esmolol / Metoprolol etc
Short laryngoscopic time is essential to avoid a marked
adrenergic response

19. INTRA-OP MANAGEMENT
Ketamine
Ketamine by itself can precipitate a moderate sympathetic
response however it is almost never used as a single agent.
When given with a combination of benozdiazepine, opioid
and an increment of propofol, this effect of Ketamine can
be blunted or even eliminated.
Ketamine might not show a sympathetic response in
patients with CHF due to depleted adrenal gland stores of
catecholamines. In fact, it is an agent of choice for such.

20. INTRA-OP MANAGEMENT
Hypotension
× Judicious correction of intravascular volume
× Small dose of direct acting agent i.e. phenylephrine (25 – 50 mcg)
may be beneficial
× Patients taking pre-op sympatholytics have a decreased response
to Ephedrine ( indirect sympathomimetic )
× Patients taking ACEI / ARB usually show hypotension due to loss of
sympathetic tone superimposed on RAS blockade, so Vasopressin
is the only intact system left
× Vasopressin as a bolus or infusion is used to restore vascular tone
in a patient with hypotension that is refractory to IV fluids and
direct agents. Phenylephrine and norepinephrine are alternatives.
× Choice must be individualized

21. INTRA-OP MANAGEMENT
Hypertension
First rule out:
× inadequate anesthetic depth and pain
× airway compromise, hypoexmia and hypercapnia
× bladder distention
× consider autonomic hyper-reflexia (if indicated)
× Pneumo-peritoneum for laparoscopic surgery can also increase
SVR and cause elevated BP measurements
Anti-hypertensives are selected keeping in mind patient’s
baseline ventricular function and broncho-spastic
pulmonary disease, as well as the nature of surgery,

22. INTRA-OP MANAGEMENT
Hypertension
× BB alone or as supplement is a good choice in patients
with good LV fx and ↑ HR but use cardioselective BB in
reactive airway disease
× CCB (nicardipine, verapamil) may be prefferable in
patients with reactive airway disease
× Nitropruside remains the most rapid/effective agent for
intra-op treatment of mod-to-severe hypertension
× Nitroglycerin, effective, maybe useful in preventing MI

23. INTRA-OP MANAGEMENT
Hypertension
× Hydralazine provides a sustained BP control but has a
delayed onset and cause a reflex tachycardia
× Reflex tachycardia is not seen with Labetalol as it is a
combined alpha and beta blocker. It is also long-acting,
so use with caution if patient is volume depleted or if
patient has conduction blockades
× Fenoldopam, a dopaminergic agonist, is useful too. It also
increases RBF

24. POST-OP

25. POST-OP MANAGEMENT
Hypertension in recovery room is often multi-factorial:
× Respiratory and airway abnormalities
× Anxiety and pain
× Volume overload
× Bladder distention
× Alpha-2 Agonist withdrawal
× Nicotine withdrawal
× Raised ICP in select cases
× Autonomic hyper-reflexia in select cases
These should be corrected accordingly and parenteral anti-
hypertensives as boluses/infusion should be given when necessary.
When oral intake is resumed, regular oral anti-hypertensives should be
restarted as soon as possible.

26. Thanks!
Any questions?