1.
Peri-operative management of
hypertension
Speaker
Dr. Tipu Sultan
Co-ordinator
Dr.Chavi Sethi(M.D.)

2.
Peri-operative Hypertension
Hypertension occuring in the pre-operative,
intra-operative or post-operative period.
Importance:
Increased risk of cardiovascular events,e.g. myocardial
ischemia
Increased post-operative morbidity and mortality
Association with end-organ damage such as renal
failure.

3.
JNC-7

4.
Effects of Peri-operative hypertension
CVS effects:
 Increased BP→ ↑ afterload & myocardial oxygen demand →
myocardial oxygen supply and demand imbalance.
 Chronic ↑ BP → myocardial hypertrophy → myocardial
oxygen supply and demand imbalance
 Hypertrophied myocardium → decreased compliance →
abnormal diastolic filling
 Diastolic dysfunction especially apparent during stress,
important during surgery and acute recovery interval

5.
CNS effects:
Increased risk of stroke
Impaired cerebral autoregulation
Especially important in neurosurgical patients
Effects on renal function
Effective control of BP prevents renal dysfunction
Intraoperative urine output monitoring for assessment
of perioperative renal function

6.
Pre-operative concerns
Preoperative evaluation important to identify
patients with
hypertension
appropriate therapy.
and
initiate
When to diagnose hypertension?
Single reading of elevated BP in patient with previous
undiagnosed or untreated HTN not reliable, subsequent
readings in non-stressful environment required. (White
Coat Hypertension)

7.
Stage 1 or stage 2 hypertension (systolic blood pressure
< 180 mm Hg and diastolic blood pressure < 110 mm Hg)
not independent risks for perioperative cardiovascular
complications, hence cancellation not always justified.
On
initial evaluation, hypertension mild or
moderate & no associated metabolic or
cardiovascular abnormalities, do not delay surgery.

8.
Stage 3 hypertension (systolic blood pressure ≥ 180 mm
Hg and diastolic blood pressure ≥ 110 mm Hg) should be
controlled before surgery.
More prone to perioperative ischemia, arrhythmias and
cardiovascular lability, but no clear cut difference that
deferring and anesthesia decreases perioperative risk.
Patients with newly diagnosed mild hypertension,
treatment may be delayed till after surgery.

9.
Management of anaesthesia in hypertensive patients:
Preoperative evaluationDetermine adequacy of blood pressure control
Review pharmacology of drugs being administered
Evaluate for evidence of end organ damage
Continue drugs used for control of blood pressure
The incidence of hypertension and evidence of
myocardial ischemia during maintenance of anesthesia is
increased in patients who are hypertensive prior to
induction of anesthesia.
Also the magnitude of blood pressure decreases during
anesthesia is greater in hypertensive than in
normotensive patients.

10.
Preoperative history and examination
End-organ damage
Associated cardiovascular pathology
Current anti hypertensive medications
To be continued during perioperative period
 Special care regarding β-blockers and clonidine

Patients with preoperative HTN, more likely to
develop intra-operative
inhibitors)
hypotension.
(ACE

11.
Preoperative β blockers:
Controversial
Proven to be beneficial in cardiac surgeries
For non-cardiac surgeries good results in high-risk
patients but not in low-risk patients (NEJM 1996, 2005)
Associated with lesser incidences of perioperative ischemia
 Intraoperative hypotension, precipitation of asthamatic
attack, major disadvantage


12.
Preoperative ACE inhibitors & AT-1 antagonists:
Controversy regarding exaggerated hypotension
As long as euvolumia, no hypotension
Pts. with preoperative BP elevations; exaggerated
intraoperative BP fluctuations & ECG evidence of
ischemia.
Preop. Control of BP; ↓tendency to perioperative
ischemia.

13.
Controversy over when to delay surgery and at
what BP to accept the patient
 Individualize the patient
Anaesthesiologists perogative
Hospital protocol

14.
Induction and maintenance of anaesthesia:
Anticipate exaggerated blood pressure response to
anesthetic drugs
Limit duration of direct laryngoscopy
Administer a balanced anesthetic to blunt hypertensive
responses
Consider placement of invasive hemodynamic monitors
Monitor for myocardial ischemia

15.
Intraoperative concerns
Target range for intraoperative BP control:
BP days to weeks before surgery
Presence of associated comorbidity
Type of surgery
Maintained within 20% of the preoperative level
Stressful intraoperative events:
Intubation
Surgical incision
Emergence from GA and extubation

16.
Other causes of intra-operative hypertension:
Inadequate depth of anesthesia
Pain
Hypercarbia
Hypoxemia
Bladder distension
Hypervolumia
Exaggerated response in hypertensive patients
Increased sympathetic tone
Decreased intravascular volume

17.
Methods to blunt the sympathetic response:
IV Esmolol (1-2mg/kg, studies with lesser dose
0.4mg/kg)
IV Lignocaine( 1.5 mg/kg, 90 sec before
intubation/extubation)
Short acting narcotics (Fentanyl 2-3µg/kg, sufentanil
0.3-0.5µg/kg)
Increased concentration of inhalational agents (MAC-ei,
MAC-bar-ei)
IV NTG (1-2µg/kg, just before beginning laryngoscopy)
IV Labetalol (5-20 mg boluses)

18.
Preoperative use of β-blockers or clonidine,
smoothen intraoperative blood pressure course.
Choice of anesthetic techniques and medications
on the basis of presence of comorbid disease and
type of surgery. (avoid ketamine)
Hypertensive patients treated with diuretics or
having LVH more susceptible to vasodilatory
effects of inhaled anesthetics & neuraxial blockade

19.
Intraoperative Hypertension
The most likely intraoperative hypertension
produced by painful stimulation, i.e., light anesthesia.
the incidence of perioperative hypertensive episodes
is increased in patients with essential hypertension,
even if the blood pressure was controlled
preoperatively
 Volatile anesthetics are useful in attenuating
sympathetic nervous system activity responsible for
pressor responses

20.
Monitoring
Monitoring in patients with essential hypertension is
influenced by the complexity of the surgery.
Electrocardiography is particularly useful in recognizing
the occurrence of myocardial ischemia during periods of
intense painful stimulation such as laryngoscopy and
tracheal intubation.
 Invasive monitoring with an intra-arterial catheter and a
central venous or pulmonary artery catheter may be useful
if extensive surgery is planned and there is evidence of left
ventricular dysfunction or other significant end-organ
damage.
 Transesophageal echocardiography is an excellent
monitor of left ventricular function and adequacy of
intravascular volume replacement

21.
Postoperative concerns
Postoperative Hypertension: Arbitrarily
defined as SBP>190 mm Hg and/or DBP≥100 mm
Hg on two consecutive readings following surgery
Implications:
Risk of hemorrhage
Disruption of vascular or cardiac suture lines
Cerebral edema
↑ myocardial wall stress and oxygen consumption→
myocardial ischemia

22.
Causes:
Preoperative hypertension
Withdrawal of antihypertensive medications
Pain
Emergence delerium
Hypoxia
Hypercarbia
Hypothermia
Hypervolumia
Type of surgery

23.
Management:
Aggressive pain management
Correction of previously mentioned causes
Antihypertensive medications
Parenteral
 Rapid onset
 Labetalol, hydralazine

Refractory or profound hypertension

SNP or NTG

24.
Risk of General Anesthesia and in Hypertensive PatientsElective Surgery
Preoperative
Systemic Blood
Pressure Status
Incidence of
Perioperative
Hypertensive
Episodes (%)
Incidence of
Postoperative
Cardiac
Complications (%)
Normotensive
8[*]
11
Treated and rendered
27
normotensive
24
Treated but remain
hypertensive
25
7
Untreated and
hypertensive
20
12
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.

25.
Isolated Systolic Hypertension (ISH)
Systolic blood pressure>140 mm Hg with a
normal diastolic blood pressure
Prevalent in elderly population (steady increase
in systolic pressure with age)
Studies have described association between ISH
and cardiovascular complications in non-cardiac
surgery (Aronson et al, Franklin et al)
No definitive studies for non-cardiac surgery

26.
Recent clinical trial and observational study data
show closer association of systolic BP with CAD
and stroke Vs diastolic BP
Recommendations for aggressive treatment of
ISH, especially in pts.> 65 yrs
Further studies required to assess anesthetic risk

27.
Acute Hypertensive Crises
Hypertensive emergencies, sudden increase in systolic and
diastolic blood pressure associated with end organ damage
of the CNS, the heart , or the kidneys.
Hypertensive urgencies,
acute end-organ damage.
Malignant
severely elevated BP without
hypertension, syndrome characterized
elevated BP accompanied by encephalopathy
nephropathy
by
or

28.
SBP >169 mm Hg or DBP >109 mm Hg in a
pregnant woman is considered a hypertensive
emergency
Majority are previously diagnosed for HTN, on
irregular treatment
The rate of rise more important than the absolute
level

29.
Pathophysiology:
Abrupt ↑ in systemic vascular resistance (humoral
vasoconstrictors)
Severe elevations of BP→ endothelial injury → fibrinoid
necrosis of the arterioles → deposition of platelets and
fibrin → breakdown of the normal autoregulatory
function.

Resulting ischemia → release of vasoactive substances

30.
Hypertensive crises
Hypertensive encephalopathy
Acute aortic dissection
Acute pulmonary edema with LVF
Acute myocardial infarction/unstable angina
Eclampsia
Acute renal failure
Pheochromocytoma crisis

31.
Clinical features:
Those of end organ damage
Hypertensive encephalopathy (headache, altered
consciousness, CNS dysfunction)
 Retinopathy (blurring of vision)
 CVS (angina, acute MI)
 Cardiac decompensation
 Renal (renal failure with oliguria and/or hematuria)


32.
Management of Hypertensive crises
Hospital Care (urgencies), ICU care (emergencies)
Invasive BP monitoring for emergencies
Lower the BP + stabilize and reverse the damage to target
organs
Sodium restriction and diuretics if fluid overload
Parenteral anti-hypertensives (emergencies),
oral/parenteral (urgencies)

33.
Drugs
Dosage
 Diazoxide
IV injection of 1 to 3 mg/kg to maximum of 150
given over 10 to 15 min; may be repeated if
inadequate response.
 Enalaprilat
IV injection of 1.25 mg over 5 min every 6 h,
titrated by increments of 1.25 mg at 12- to 24-h
intervals to a maximum of 5 mg every 6 h.
 Esmolol
Loading dose of 500 µg/kg over 1 min, followed
an infusion at 25 to 50 µg/kg/min, which may
increased by 25 µg/kg/min every 10 to 20 min
the desired response to a maximum of
300µg/kg/min.
mg
by
be
until

34.
 Fenoldopam
maximum
An initial dose of 0.1 µg/kg/min, titrated by
increments of 0.05 to 0.1 µg/kg/min to a
of 1.6 µg/kg/min.
 Labetalol
Initial bolus 20 mg, followed by boluses of 20 to
mg or an infusion starting at 2 mg/min;
cumulative dose of 300 mg over 24 h.
 Nicardipine
5 mg/h; titrate to effect by increasing 2.5
mg/h every 5 min to a maximum of 15 mg/h.
 NTG
Infusion @ 5 µg/min, increase by 5 µg/min
5 min
80
maximum
every 3-

35.
 Nitroprusside
0.5 µg/kg/min; titrate as tolerated to maximum
µg/kg/min.
 Phentolamine
1- to 5-mg boluses; maximum dose, 15
mg.
of 2
 Trimethaphan
0.5
mg/min.
0.5 to 1 mg/min; titrate by increasing by
mg/min as tolerated; maximum dose, 15