hypertension in anesthesia1
TRANSCRIPT
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