Hypertension in anesthesia1

Hypertensive surgical patient

Dr. S. Parthasarathy MD., DA., DNB, MD (Acu), Dip. Diab. DCA, Dip.

Software statistics- PhD ( physiology), ( IDRA )

• Commonest cause of case cancellation in a preanesthetic clinic is

• Hypertension ± hypokalemia

Incidence

• The total incidence of hypertension in preoperative phase

was 10.16%.

• Among them 64.9% being male and 35.1% female. Maximum

incidence was found in age group 50-59 years i.e. 26.6%.

• Among the case detected maximum patients i.e. 52% were

patients with newly diagnosed hypertension

• 61.1% were using calcium channel blockers.

One in ten – we encounter

• Primary - 95 % • ( Without any cause )• Secondary – 5 % • renal • Endocrine • Neurogenic • Coarctation etc..

Clinical picture ?? !!

• “Vasoconstricted” hypertension—in medical patient with

chronic renovascular hypertension, characterized by diastolic

hypertension and ↑ systemic vascular resistance

with normal or even decreased cardiac output and heart rate.

• “Hyperdynamic” hypertension—in postoperative surgical

patient, characterized by acute systolic hypertension; widened

pulse pressure; and increased cardiac output, heart rate

Why we need to know

• Is it primary or secondary ?? • End organ damage - associated • A sudden intraoperative rise – ICH or LV failure !! • Increased incidences of myocardial ischemic

episodes • On induction changes more • On intubation changes more • Overall cardiac risk higher

What do we note as anesthetist ?

• Control of hypertension – adequacy ?? • Up to a Diastolic of 110 – OK • 160/ 110 is ok for elective case – debate going

on • Pharmacology of drugs !!

Drugs

• Beta blockers (with vasodilation) ( HR of 60)• Calcium channel blockers • ACE inhibitors • ARBs • Diuretics -- (more in ISH)• Garlic and anticoagulation

Does it matter ?

• co-existing hypertension may increase the incidence of postoperative

myocardial reinfarction in patients with a history of myocardial

infarction

• Incidence of neurologic complications in patients undergoing carotid

endarterectomy.

• In hypertensive patients who exhibit signs of target organ damage,

postponement of an elective procedure is justified if that end-organ

damage can be improved or if further evaluation of that damage could

alter the anesthetic plan.

• BP of 150/90 • But creatinine is 1.8 – • Check if There is LVH

• Can we improve that ?• Does it alter the anesthetic process and plan ?

Clinical pearls

• LVH is associated with systolic hypertension more

• Renal end organ damage is associated with more perioperative morbidity

• History of TIA,. Old CVA – look for fundus

• White coat hypertension

• NIBP can overestimate in elderly hypertensives

• PAC – MGMCRI White-coat hypertension (WCHT) is defined as a nurse-taken blood pressure of <140/90 when compared with a physician-taken value of >160/95.

When to postpone ?

• Stage 3 hypertension – 180/ 110 or more Stage 2 hypertension with end organ damage• Eg. 170/106 with nephropathy (Creat - > 2)

• Patients with newly diagnosed mild hypertension, treatment may be delayed till after surgery.

Cancel ?? !!

• when canceling a procedure for adequate BP control,

one must be aware that this may take 3 to 4 weeks and

in some cases, up to two months.

• There is no benefit in postponing the procedure for one

or two days, which would only bring inconveniences for

patients and the hospital.

• End organ damage is different

What is the procedure

• Cosmetic surgery • Or • Oncological surgery • Or • Hip fracture

• Medico legal issues

Individualize

Vascular procedure , major blood loss expected

Further cardiac evaluation

Now – any idea ??

• Diastolic more than 110 with dyslipidemia with smoking with proteinuria

• Totally elective case – can wait • How long to wait ??

• Aggressive treatment with anxiolytics, statins and antihypertensives – 30 days !!

drugs – to continue or not

• The safety of β-blockers and their benefits (prevention of

hypertensive responses, dysrhythmias, and myocardial ischemia)

have been long established.

• ACE inhibitors – hypotension on induction common – but not to

discontinue – (plan regional – may stop the drug )

• Better to stop ACE inhibitors if major surgery with fluid shifts

expected

• Amlodipine – continue

• Diuretics also continue – but check on electrolytes and volume status

Prys robert school of thoughts

• Patients with atherosclerotic disease, who present

with raised systolic pressure, but normal or low

diastolic pressure, should not be considered as true

hypertensive and should not have their surgery

delayed

Goldman and Caldera school

• Diastolic more than 110

• End organ damage

• Must to treat

Potassium

• Upto 3 =OK • Less than 3 – can correct with oral or change of drugs

if not any urgency • Otherwise – IV potassium correction • Chronic diuretic use – can we correct ? Harmful !• But chronic hypokalemia does not seem to increase

perioperative complications –• more Useful in patients with cardiac illness• With digoxin – act

Risk factors in hypertensives

General

Preoperative essence

• Primary or secondary

• Stage – treated or not – severe- white coat ?

• Target organ damage

• CVA , CAD , LVH , Creatinine

• X-ray in hypertensive breathless patients

ECG and creatinine

Premedication • Anxiolysis • Beta blockers CCBs to continue • ARBs – can be discontinued – refractory

hypotension- possibly 10 hours • Clonidine – better hemodynamics and

sedation – think of withdrawal also • dexmed-Better in myocardial infarction,

myocardial ischemia) but an increased incidence of hypotension and bradycardia

Intraoperative hypertension

• Intraoperatively esmolol, where available, may be very

valuable for controlling sudden tachycardia and

hypertension, but remember

• Labetolol - if the hypertensive event is due to an excess

of catecholamines, caused either by administration of

adrenaline or cocaine by the surgeon, or by

endogenous secretion (e.g. phaeochromocytoma).

Induction

• Thiopentone • Propofol

• Etomidate – ok

• No to ketamine

Excess hypotension- beware ?

Laryngoscopy and intubation

• Hypertensives made normal also show exaggerated response

• Agent, fentanyl, IV lignocaine ,IV nitroprusside IV esmolol – 15 seconds – put the tube

• Think of exaggerated hypotension than allow a small increase in BP also !!

• Surgical stimulation • Opioid • Agent • Local • Esmolol

Extubation

Lignocaine Opioids Smooth

Maintenance of Anesthesia

• MAP – maintained between 20 % of baseline is the aim than the technique

• Agent • Vecuronium • Regional • Narcotics • Nitroprusside

IPPV and hypocapnia can decrease cardiac output

Hypocapnia can cause hypokalemia in patients

receiving diuretics

Which case ?

• The monitoring can extend from simple manual BP monitoring

• to intra-arterial BP monitoring to automatic NIBP, ECG, pulse oximeter, capnography, PAWP, transesophageal echocardiography, etc

• Monitor under the table • Monitor blood loss

Hypothermia can increase

intraoperative BP

• During anesthesia, exaggerated decreases in blood

pressure seen with blood loss, positive pressure

ventilation, or sudden changes in body position

• Are we dealing with drugs affecting ANS

Drugs for hypertensive crisis

10 mic/ minute

5 mg slow IV in incremental doses

Regional anesthesia

• Nerve blocks – good • Neuraxial – Acceptable • less drastic fall – epidural • Intrathecal narcotics • Ephedrine better than phenylephrine to

counter hypo in neuraxial blocks • Sometimes we need vasopressin• May unmask hypovolemia

We don’t want these in post op period

• Hypoxemia • Full bladder • Shivering • Pain • Anxiety

Postoperative period- sometimes late

• Hypertension may also be the result of intravascular

volume overload from excessive intraoperative

intravenous fluid therapy, and persist 24 to 48 hours

until the fluid has been mobilized from the

extravascular space.

• Blood pressure can also rise due to discontinuation of

blood pressure medications postoperatively

Summary • Hypertension – common cause of cancellation• Stages and when to intervene • 4-6 weeks to normalize autoregulation • End organ damage • Drugs to continue • Premedicate • Induce and intubate – smooth – 20 % BP • IPPV and PaCO2 maintain• Extubate smooth • Drugs to continue

Thank you all