Download Perioperative hypertension: Diagnosis and Treatment

Netherlands Journal of Critical Care
Copyright © 2011, Nederlandse Vereniging voor Intensive Care. All Rights Reserved. Received April 2010; accepted September 2010
Review
“Perioperative hypertension: Diagnosis and Treatment”
KM Soto-Ruiz1, WF Peacock2, J Varon3
1 Dorrington Medical Associates, Houston, Texas and School of medicine, Autonomous University of Baja California, Tijuana, Mexico
2 Department of Emergency Medicine, The Cleveland Clinic, Cleveland, United States of America
3 The University of Texas Health Science Center at Houston, and The University of Texas Medical Branch at Galveston. St. Luke’s
Episcopal Hospital/Texas Heart Institute, Houston, United States of America
Abstract - With hypertension affecting more people every year, it is commonly encountered in the perioperative setting by
anaesthesiologists, surgeons, intensivists, and internists. The presence of perioperative hypertension poses a risk for patients that can
affect the morbidity and mortality of a surgical procedure. Despite well documented findings of complications that can arise from this
condition, and the beneficial effects of therapeutic management, there are few diagnostic or treatment guidelines. Multiple agents can
be used in the acute setting of perioperative hypertension, however some of the agents currently available are less than ideal. We have
reviewed current and emerging pharmacological agents available.
Keywords - Hypertension, cardiac surgery, surgery, hypertensive crisis, hypertension management, preoperative, perioperative, postoperative
Introduction
It is estimated that there are currently 73 million people in the
United States with hypertension [1]. Affecting more than 30%
of the population over 20 years of age, it is one of the most
common chronic medical pathologies [2]. Hypertension, seen as
a significant public health problem, is not uniformally distributed
as it occurs twice as often in African Americans compared
with Caucasians [3] and affects men more than women [4].
From a global perspective, the World Health Organization has
predicted that by 2025 one third of the world’s population will
be hypertensive, and this will be responsible for over 7.1 million
deaths per year [5].
Hypertension is a major risk factor for adverse cardiovascular
outcomes, renal disease, and stroke [5]. Furthermore, it has
been established that treating hypertension reduces the risk
of these conditions developing [6]. Consequently, the Joint
National Committee on Prevention, Detection, Evaluation,
and Treatment of High Blood Pressure (JNC VII) recommends
risk factor modification and treatment with antihypertensive
agents in patients with systolic blood pressure (SBP) greater
than 140mmHg and/or diastolic blood pressure (DBP) greater
than 90mmHg, regardless of age [7]. While these parameters
represent a guide for chronic hypertension management, they are
even more critical in patients undergoing operative interventions
where the risks of adverse outcomes are increased.
Methods
We performed a PubMed search to identify suitable articles
to review. A systematic review was performed with the
Correspondence
J Varon
E-mail: [email protected]
following terms: hypertension epidemiology, management and
complications, preoperative care, perioperative hypertension,
postoperative hypertension, postoperative complications, and
periprocedural hypertension. In addition, articles were sought
in the specific areas of neurosurgical operations complications,
cardiac and non-cardiac surgery mortality, and antihypertensive
therapy/agents. From the results of our search we reviewed 45
papers.
Perioperative hypertension
Because hypertension is so common, it is frequently detected
in patients about to undergo surgery [8]. The presence of
preoperative hypertension portends more difficult haemodynamic
control during anaesthesia, increased risk of intraoperative and
postoperative cardiovascular events, and challenges with postprocedural blood pressure control [9]. Just the presence alone of
hypertension is a risk factor for other cardiovascular diseases that
may contribute to perioperative adverse events [9]. In fact, the
National Veterans Administration Surgical Risk study of 83,000
patients found hypertension was the second most common risk
factor associated with surgical morbidity [10].
Perioperative hypertension can occur during the induction
of anaesthesia. Intraoperative hypertension is associated with
acute pain-induced sympathetic stimulation that leads to
vasoconstriction. In the post anaesthesia period, hypertension
can be associated with pain-induced sympathetic stimulation,
hypothermia, and/or hypoxia. 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 [11]. Postoperative hypertension
has a variable incidence ranging from 4% to 30%, following
cardiac or non-cardiac surgery [12].
NETH J CRIT CARE - VOLUME 15 - NO 3 - JUNE 2011
143
Netherlands Journal of Critical Care
KM Soto-Ruiz, WF Peacock, J Varon
Preoperative hypertension
At least 25% of patients undergoing non-cardiac surgery will
have hypertension before undergoing their procedure. This
has important outcome implications as high blood pressure is
associated with complications such as myocardial ischaemia.
Preoperative hypertension is frequently a hypertensive urgency
- not an emergency - as it doesn’t involve end organ damage
and there is usually enough time to reduce the blood pressure
[13]. It has been suggested that a DBP of 110mmHg or above
is considered a preoperative marker of perioperative cardiac
complications in patients with chronic hypertension [8,11]. In a
study by Forrest et al., preoperative hypertension was associated
with perioperative bradycardia, tachycardia, and hypertension
[14], and Browner et al found a 3.8 times increase on postoperative
death when compared to normotensive patients [15].
When hypertension is detected, a work up for secondary causes
of hypertension should be done. Even though pheochromocytoma
is rare, if present, it can produce serious complications during
a procedure. Long-term excess catecholamine stimulation can
produce vasoconstriction and hypovolaemia that can potentially
complicate management [9].
Clonidine withdrawal syndrome can simulate the hypertensive
crisis of pheochromocytoma. This can be misdiagnosed
as symptoms usually present 18 to 24 hours after sudden
discontinuation of clonidine. When detected, clonidine
withdrawal symptoms can be corrected simply by administering
intramuscular clonidine or treating with labetalol and methyldopa
[11].
Intraoperative hypertension
Intraoperative acute blood pressure elevations of over 20%
during surgery are considered a hypertensive emergency,
and chronic hypertensive patients are more likely to have
labile haemodynamics during a procedure. Even small blood
pressure elevations during surgery can result in increased risk
of post-operative mortality and renal failure, especially during
cardiovascular procedures. Hypertensive events occur more
commonly in patients undergoing surgery of the carotids,
followed by abdominal aorta, peripheral vascular procedures,
intraperitoneal, and intrathoracic surgery [8]. Patients undergoing
cardiac surgery represent a unique pathophysiologic cohort
in perioperative hypertensive management. Hypertension in
this group is characterized by peripheral vasoconstriction and
reduced baroreceptor sensitivity. [16] Because of pre-existing
underlying pathology, elevated blood pressure and heart rate
can place a patient with preexisting left ventricle dysfunction
or coronary artery disease at risk for developing myocardial
ischemia or heart failure [17].
Acute postoperative hypertension (APH)
Postoperative hypertension is more common in preoperative
hypertensive patients, and in those undergoing vascular
procedures[18]. It has been defined as an SBP of above 190
mmHg and/or DBP of 100 mmHg on two consecutive readings
after surgical intervention [11]. Postoperative hypertension
144
NETH J CRIT CARE - VOLUME 15 - NO 3 - JUNE 2011
episodes occur in the first 20 minutes of the postoperative
period, although its resolution can require up to 3 hours [19-22].
If left untreated, postoperative hypertension increases the risk
of myocardial ischaemia, myocardial infarction, cerebrovascular
accidents, and bleeding [11].
APH is characterized by peripheral vasoconstriction,
catecholamine release and reduced baroreceptor sensitivity
[23]. Some of the complications associated with APH are,
myocardial ischaemia, myocardial infarction, cardiac arrhythmia,
congestive heart failure, pulmonary oedema, cerebral ischaemia,
hemorrhagic stroke and encephalopathy; it also increases the
risk of bleeding from the surgical site [5].
Myocardial ischaemia most commonly occurs in the
postoperative setting and may present hours to days after the
surgical procedure. Several factors may increase the risk of
myocardial ischaemia, and include oxygenation problems,
altered thrombotic potential, tachycardia, and postoperative
hypertension that increases myocardial oxygen demand.
Postoperative hypertension can also cause pulmonary oedema
in patients with preexisting left ventricular systolic cardiac
dysfunction [9].
Rose et al., found that patients that presented with
intraoperative hypertension, excessive pain, and inadequate
ventilation had a higher risk of developing APH, and also noted
that these patients had more critical care admissions and a higher
risk of mortality [24]. Additionally, a unique cause of hypertension
may occur after surgical repair of coarctation of the aorta in two
ways: an early component during the first 36 hours of systolic
hypertension, and a late component of systolic and/or diastolic
hypertension that persists beyond postoperative day two. If it
persists beyond day two, there is an increased risk of developing
postcoarctectomy syndrome, characterized by abdominal pain
and associated mesenteric arteritis [25, 26].
Management
Before starting antihypertensive pharmacological treatment,
other reversible causes of postoperative hypertension should be
addressed. These include pain, hypoxia, hypercarbia, agitation,
bladder distension and hypervolaemia [18]. Appropriate analgesia
and sedation should be considered a prerequisite to the initiation
of antihypertensive therapy [27]. If a patient is hypertensive and
unable to take oral agents, parenteral therapy should be used
[18], this makes drugs such as clonidine less attractive, as they
are available only in oral or transdermal presentation and this
makes titration a challenge. Volume status should be assessed as
intravascular volume depletion can increase sympathetic activity
and vasoconstriction, thus contributing to hypertension [5]
When hypertension is present, the distinction between an
emergency and an urgency is useful. Hypertensive emergencies
are defined by the coexistence of end organ damage, and a
parenteral antihypertensive agent is usually necessary. In the
acute setting, the goal of blood pressure management should
be a 25% decrease in systolic BP. It is believed the immediate
therapeutic goal should be to reduce DBP by 10% to 15% or
to 110 mmHg in 30 to 60 minutes [11]. Some of the therapeutic
Netherlands Journal of Critical Care
“Perioperative hypertension: Diagnosis and Treatment”
options for parenteral blood pressure management are described
below (See Table 1):
Clevidipine
Clevidipine is a third generation dihydropyridine calcium channel
blocker. Metabolized by red blood cell (RBC) esterases, it has a
half-life of 1-2 minutes which is not altered by renal or hepatic
failure. An arterially selective vasodilator, clevidipine reduces
afterload without affecting cardiac filling pressures and is not
reported to cause reflex tachycardia. A direct coronary vasodilator,
clevidipine increases coronary blood flow while increasing
stroke volume and cardiac output. Clevidipine protects against
ischaemia/reperfusion injury, and maintains splanchnic blood
flow and renal function [5].
A clevidipine infusion is started at a rate of 0.4µg/kg/min,
titrating by doubling increments every 90 seconds up to 3.2µg/
kg/min. Because it is manufactured in a lipid emulsion, it is
recommended that the infusion set up be changed every four
hours to prevent the possibility of bacterial contamination.
Furthermore, the maximal 24 hour dosage should not exceed
2.5g/kg [28], and clevidipine should not be given to patients with
soy or egg allergies
A comparative effectiveness trial of clevidipine versus
nitroglycerin, nicardipine, and nitroprusside has been performed
[28]. The Evaluation of CLevidipine In the Perioperative
Treatment of Hypertension Assessing Safety Events (Eclipse)
trial prospectively evaluated outcomes in1512 cardiac surgical
patients that required treatment for APH. In this analysis, the
clevidipine cohort was found to have a significantly lower mortality
rate as compared to the nitroprusside group. Clevidipine was also
found to achieve goal SBP more effectively than nitroglycerin or
nitroprusside.
Table 1. Therapeutic options in the management of perioperative hypertension
Drug
Dose
Time of action
Contraindications/Adverse
effects
Clevidipine
Infusion rate started at a rate of 0.4 µg/kg/
min, titrating by doubling increments every 90
seconds up to 3.2 µg/kg/min, up to a maximum
of 2.5g/kg/24hours
Half-life of one minute, duration
of action 5-15 mins
Cannot be given in patient with egg or
soy allergy.
Infusion set up should be changed
every 4 hours
Nicardipine
5mg/hr, increasing 2.5mg/hr every 5 minutes up
to a maximum of 15mg/hr
Onset of action is 5 to 15
minutes, duration of action is 4
to 6 hours
Increased half-life may results in
prolonged action by 24 hours of use
Nitroglycerin
Starting dose is 5 µg/kg/min, it can be titrated
at 5 µg /kg/min every 3-5mins, after dose
exceeds 20 µg /kg/min, it can be incremented
at 20 µg /kg/min
onset of action is 2 to 5 minutes,
duration of action is 3 to 5
minutes
Hypotension and reflex tachycardia.
Tachyphylaxis onset within 4 hours.
Methemoglobinemia with prolonged
infusion
Nitroprusside
0.25 to 0.5mg/kg/min titrated every 1-2 minutes
Onset of action is seconds, the
duration of action is 1-2 minutes,
and plasma half-life is 3 to 4
minutes
Decreases renal blood flow and
function.
Decreases cerebral blood flow but
increases intracranial pressure.
Coronary steal
Prolonged infusion may result in
cyanide toxicity
Hydralazine
IV bolus: 10-20 mg repeated every 1-4 hours
as needed.
IV Infusion: loading dose of 0.1 mg/kg, followed
by a continuous infusion of 1.5-5 mcg/kg/min
Onset of action is 5 to 25 mins,
drop in BP can last up to 12
hours. Circulating half-life is 3
hours
Reflex tachycardia in ischaemic heart
disease may result in iatrogenic MI
Avoid in patients with dissecting
aneurysms.
It can increase intracranial pressure
Fenoldopam
Starting dose is 0.1 µg/kg/min, titrated by
increments of 0.05-0.1 µg/kg/min, up to a
maximum of 1.6 µg/kg/min
Onset of action 5 mins, maximal
response at 15 mins. Elimination
half-life is 5 mins, duration of
action is 30-60 mins.
Tachycardia
Increase intraocular pressure
Labetalol
Loading dose 20mg followed by 20-80mg every
10mins. After initial dose, a 1-2mg/min infusion
titrated until desired effect has been achieved
Onset of action is 2-5 mins, it
reaches a peak at 5-15 minutes
and lasts up to 4 hours, its
elimination half-life is 5.5 hours
Should not be used in patients with
acute heart failure, bradycardia, heart
block >1st degree, bronchospasm
Esmolol
500-1000 µg /kg
loading dose in 1 min, followed by infusion
starting at 50 µg/kg/min and increasing up to
300 µg/kg/min PRN
Onset of 60 seconds and a short
duration of action of 10 to 20
minutes
Anaemia can prolong its half-life.
Should not use with acute heart failure,
bradycardia, heart block >1st degree,
bronchospasm
Enalaprilat
1.25mg in over 5 min every 6 hours titrated
by increments of 1.25mg at 12-24 hours to a
maximum of 5mg every 6 hours
Onset of action 15 minutes, peak
effect in an hour, duration of
action is 6 hours
Variable response, slow onset of action,
difficult to titrate to effect
NETH J CRIT CARE - VOLUME 15 - NO 3 - JUNE 2011
145
Netherlands Journal of Critical Care
KM Soto-Ruiz, WF Peacock, J Varon
Nicardipine
Nicardipine is a second generation dihydropyridine calcium
channel blocker. It has high arterial vascular selectivity, with
strong coronary and cerebral vasodilator activity that results in
increased, as well as preserved coronary and cerebral blood flow
[11]. Its onset of action is 5 to 15 minutes, and it has a four to
six hour duration of action. Nicardipine’s dosing is independent
of weight. Its initial infusion rate is 5mg/hr, and this can be
increased by 2.5mg/hr, every five minutes, up to a maximum of
15mg/hr. Blood pressure control is usually achieved within 10 to
15 minutes, and few adjustments are needed to maintain control
[5]. Nicardipine initially has a short duration of effect, however, it
has the disadvantage of an increasing half-life during the next 24
hours that may result in a prolonged duration of action.
Nitroglycerin
Nitroglycerin is a potent venodilator that does not cause arterial
vasodilation until higher doses are reached. Its recommended
starting dose is 5µg/kg/min, then titrated upward at 5µg/kg/min
every three to five minutes. After the initial dose has exceeded
20µg/kg/min, dosage can be increased by 20µg/kg/min
increments. Some clinical scenarios may require more rapid up
titration, such as acute pulmonary oedema, although this should
be done with caution and very close monitoring. Even though there
are no dosing limits, the risk of iatrogenic hypotension increases
at doses higher than 200 µg/kg/min. The onset of action of
nitroglycerin is two to five minutes, and it has a duration of action
of three to five minutes. Tachyphylaxis which begins as early as
four hours after IV initiation, limits its utility as a long-term blood
pressure management agent. Finally, excessively prolonged use
has also been associated with methemoglobinaemia [29].
The hypotensive effect of nitroglycerin is achieved by a
reduction in preload and cardiac output. Therefore, it is not
recommended for use in volume-depleted patients, or in those
in whom cardiac output is preload dependent. Hypotension
(i.e., overshoot of titration) and reflex tachycardia are common
effects of nitroglycerin, and this could be exacerbated by volume
depletion.
Nitroglycerin is recommended only as adjunct therapy for
patients with acute coronary syndromes, or in the setting of acute
pulmonary oedema. In other conditions it is not recommended
as a single primary blood pressure control agent due to its
unpredictability to reduce blood pressure and the early onset of
tachyphylaxis.
Nitroprusside
Nitroprusside is an arterial and venous vasodilator and thus
decreases both preload and afterload. It has onset of action
measured in seconds, a duration of action of 1-2 minutes,
and its plasma half-life is 3-4 minutes. It is given at an initial
dose of 0.25 to 0.5 µg/kg/min and titrated every 1-2 minutes.
Because of its significant hypotensive effects, nitroprusside
use is commonly associated with precipitous blood pressure
decreases (overshooting the desired blood pressure titration
target). The clinician should be vigilant to address this iatrogenic
146
NETH J CRIT CARE - VOLUME 15 - NO 3 - JUNE 2011
complication promptly by termination of the infusion, and
potentially administering a fluid bolus, should this occur.
The vasodilatory effect of nitroprusside can negatively impact
end organ function. Because it decreases renal blood flow, this
renal function can be impaired. Furthermore, while decreasing
cerebral blood flow, its use results in increased intracranial
pressure, therefore it should be avoided in patients undergoing
craniotomies, or in those in whom increased intracranial pressure
could be potentially harmful. Finally, the use of nitroprusside
in patients with recent MI has been associated with increased
mortality, hypothesized due to a reduction in regional blood flow
(coronary steal). Ultimately, its use should also be avoided in
these populations [5].
Nitroprusside contains a significant amount of cyanide that
is released non-enzymatically in a dose-dependant fashion
within the blood stream. It has been shown that the infusion of
as little as 4µg/kg/min over 2-3 hours, can lead to toxic levels of
cyanide. Nitroprusside can also cause toxicity with the release of
nitric oxide generated by the formation of hydroxyl radical and
peroxynitrite; this leads to lipid peroxidation [5].
Because of its potentially toxic effects, nitroprusside is only
recommended for use when no other agent is available, and only
if the patient has normal renal and hepatic function. Even in these
settings, the use of nitroprusside should be limited to as short a
time as possible, and the dose should not exceed 2µg/kg/min [5].
Hydralazine
A direct-acting arteriolar vasodilator, hydralazine demonstrates
greater blood pressure lowering effect on diastolic, rather than
systolic pressure. Hydralazine increases renal blood flow, which
may provide some theoretical advantage for patients with
impaired renal function. Regardless of whether administered
intravenously or intramuscularly, its onset of action is 5 to 25
minutes, with a maximum effect generally within 10 to 80 minutes
after administration. Hydralazine’s metabolism is dependent on
hepatic acetylation and inactivation, which results in its prolonged
effect. Although its circulating half-life is only three hours, it has
a much longer effect on blood pressure. Once given, hydralazine
can result in a drop in blood pressure that can last as long as 12
hours. Ultimately, hydralazine is not considered an ideal agent for
hypertensive crises due to its difficult titration.
Hydralazine reduces peripheral vascular resistance, but can
trigger reflex tachycardia. Because tachycardia in the setting
of hypertension results in a subsequent increase in myocardial
oxygen demand, hydralazine is not an ideal agent in patients
with potential ischaemic heart disease. Furthermore, hydralazine
should also be avoided in patients with dissecting aneurysms
due to its potential for a reflex increase in cardiac output and
myocardial contractility.
One population in whom hydralazine is preferred for use in
blood pressure control is during pregnancy. While it has long been
the drug of choice for preeclampsia, a population with little risk of
harm due to reflex tachycardia and increased myocardial oxygen
demand, a recent meta-analysis has suggested that its use is
associated with an increase in materno-fetal complications [30].
Netherlands Journal of Critical Care
“Perioperative hypertension: Diagnosis and Treatment”
Finally, hydralazine has also been reported to increase
intracranial pressure [31]. Thus it should be avoided in patients
in whom potentially increased intracranial pressures would be
contraindicated.
Fenoldopam
Fenoldopam is a dopamine-1 receptor agonist that mediates
vasodilation by its effect on peripheral dopamine-1 receptors.
Quickly metabolized by conjugation in the liver, without the
participation of cytochrome P-450 enzymes, fenoldopam
mediates renal arterial vasodilation and activates dopamine
receptors in the proximal and distal tubules. The net renal effects
are to inhibit sodium reabsorption, thus promoting diuresis and
natriuresis [5].
After administration of fenoldopam, the onset of effect is within
5 minutes, and maximal response is achieved by 15 minutes. The
elimination half-life is 5 minutes and its duration of action is from
30 to 60 minutes. The starting dose is 0.1µg/kg/min, titrated by
increments of 0.05-0.1µg/kg/min, up to a maximum of 1.6µg/
kg/min. While fenoldopam reduces blood pressure, it often
causes reflex tachycardia and can increase intraocular pressure.
Therefore, fenoldopam should be avoided in patients at risk of
myocardial ischaemia, intraocular or intracranial hypertension
[11].
Labetalol
Labetalol is a combined selective α1- and non-selective
β-adrenergic blocker, that is given as a bolus or a continuous
infusion. Metabolized by the liver to form an inactive glucuronide
conjugate, it has an onset of action within 2 to 5 minutes, reaches
peak effects at 5 to 15 minutes, has an elimination half-life of 5.5
hours, and has a duration of action of up to four hours. These
characteristics make it difficult to titrate labetalol as a continuous
infusion. It is recommended that labetalol be administered by a
20 mg loading dose, followed by additional 20 to 80 mg boluses
at 10 minutes intervals. After the initial loading dose, labetalol
may also be given as an infusion of 1 mg to 2 mg per minute,
titrated until the desired effect has been achieved.
Labetalol reduces systemic vascular resistance without
affecting peripheral blood flow. Furthermore, cerebral, renal,
and coronary blood flow are also maintained, as well as cardiac
output, but heart rate may decrease due to its β-blocking effects.
Labetalol has been found to be safe and effective for treating
APH after vascular, cardiac, general, and intracranial surgical
procedures, where a response rate of 85-100% has been
reported [5]. Labetalol should not be used in patients with severe
sinus bradycardia, asthma, and heart blocks greater than first
degree [11].
Esmolol
Esmolol is an ultra-short acting cardioselective β-adrenergic
blocking agent. It is metabolized via rapid hydrolysis of ester
linkages by RBC esterases, and thus has the advantage of
being unaffected by renal or hepatic dysfunction. Esmolol is
recommended for use in hypertensive patients with increased
cardiac output and heart rate [11]. Its hypotensive effect is
achieved by decreasing heart rate and myocardial contractility,
thereby reducing arterial pressure and it has no vasodilatory
effect.
Esmolol is administered as a 500-1000µg/kg loading dose
over one minute, followed by a continuous infusion starting at
50µg/kg/min and increasing up to 300µg/kg/min as necessary.
It has an onset of 60 seconds and a short duration of action
of only 10 to 20 minutes. Because of its RBC dependent
metabolism, any condition associated with anaemia may result in
a prolonged half-life and longer duration of hypotensive effects.
The American College of Cardiology/ American Heart Association
guidelines state esmolol is contraindicated in patients already
on β-blockers, those with bradycardia, or in the setting of acute
decompensated heart failure as it has the potential to excessively
impair myocardial function.
Enalaprilat
An IV ACE inhibitor, enalaprilat is effective treating hypertension in
patients with congestive heart failure and essential hypertension.
It has also been found to prevent worsening renal function
in patients with diabetic and non-diabetic nephropathy. For
perioperative use, it has been specifically reported to be effective
in patients undergoing craniotomies [32].
Enalaprilat is generally administered IV with a starting dose
of 1.25 mg over five minutes and repeated every six hours as
needed. It can be titrated in increments of 1.25 mg at 12 to 24
hour intervals, to a maximum of 5 mg every six hours.
The use of enalaprilat has several advantages. It can be
administered as a bolus instead of a continuous infusion, it has
no effect on intracranial pressure, and it doesn’t produce reflex
tachycardia. Disadvantages to its use are that it has a delayed
onset of action of 15 minutes, requires one hour to reach peak
effect, and its six hour duration of action is excessively long in the
potentially unstable patient. These disadvantages limit enalaprilat
use in hypertensive emergencies as a slow onset and delayed
time to peak effect make titration to a precise blood pressure
challenging [11]. Despite these concerns, enalaprilat has been
used to achieve postoperative blood pressure control when
combined with a faster acting drug that is easier to titrate, such
as labetalol or nicardipine [5].
Conclusions
Acute postoperative hypertension is common after cardiac and
non-cardiac surgery and frequently requires pharmacological
treatment. The goal of treatment should be to protect organ
function, decrease complications, and improve the outcomes.
As there are no guidelines for management and no definitive
treatment exists, emphasis must be to individualize therapy
based on the patient’s risk factors and coexisting morbidities, the
clinician’s experience, and the clinical setting.
With the implementation of antihypertensive therapy, patients
should be closely monitored to reduce the risk of iatrogenic end
organ hypoperfusion. The ideal pharmacological agent should
have an immediate onset of action, a short to intermediate
NETH J CRIT CARE - VOLUME 15 - NO 3 - JUNE 2011
147
Netherlands Journal of Critical Care
KM Soto-Ruiz, WF Peacock, J Varon
duration of action, be easily and predictably titratable, have
documented efficacy in treating perioperative hypertension,
and should be proven safe. Nitroprusside should only be used
when no other agents are available. Enalaprilat and nitroglycerin
are recommended for combined therapy, but not as single
agents. Labetalol, esmolol, hydralazine, and fenoldopam are
recommended in very specific circumstances, and attention
must be paid to their possible adverse effects. Nicardipine and
clevidipine are currently the agents recommended for the majority
of perioperative cases requiring hypertensive management as
their efficacy has been well documented and they are proven to
be safe.
References
1. Rosamond W. Flegal K, Friday G, et al. Heart disease and stroke statistics--2007
17. Charlson ME, MacKenzie CR, Gold JP, et al. Risk for postoperative congestive heart
update: a report from the American Heart Association Statistics Committee and Stroke
failure. Surg Gynecol Obstet 1991; 172:95-104.
Statistics Subcommittee. Circulation 2007;115:69-171.
18. Samson RH, Periprocedural hypertension: current concepts in management for the
2. Hajjar I, TA Kotchen. Trends in prevalence, awareness, treatment, and control of
vascular surgeon. Vasc Endovascular Surg 2004; 38:361-6.
hypertension in the United States, 1988-2000. JAMA 2003;290:199-206.
19. Gal TJ, Cooperman LH. Hypertension in the immediate postoperative period. Br J
3. Burt VL, Cutler JA, Higgins M, et al., Trends in the prevalence, awareness, treatment,
Anaesth 1975; 47:70-4.
and control of hypertension in the adult US population. Data from the health examination
20. Seltzer JL, Gerson JI, Grogono AW. Hypertension in perioperative period. N Y State
surveys, 1960 to 1991. Hypertension 1995;26:60-9.
J Med 1980; 80:29-31.
4. Dannenberg AL, Garrison RJ, Kannel WB. Incidence of hypertension in the Framing-
21. McGuirt WF, May JS. Postoperative hypertension associated with radical neck dis-
ham Study. Am J Public Health 1988;78:676-9.
section. Arch Otolaryngol Head Neck Surg 1987; 113:1098-100.
5. Marik PE, Varon J. Perioperative hypertension: a review of current and emerging
22. Riles TS, Kopelman I, Imparato AM. Myocardial infarction following carotid endarter-
therapeutic agents. J Clin Anesth 2009;21:220-9.
ectomy: a review of 683 operations. Surgery 1979; 85:249-52.
6. Turnbull F. Blood pressure lowering treatment trialists’ Collaboration. Effects of
23. Estafanous FG, Tarazi RC. Systemic arterial hypertension associated with cardiac
different blood-pressure-lowering regimens on major cardiovascular events: results of
surgery. Am J Cardiol 1980; 46:685-94.
prospectively-designed overviews of randomised trials. Lancet 2003;362:1527-35.
24. Rose DK, Cohen MM, DeBoer DP. Cardiovascular events in the postanesthesia care
7. Chobanian AV, Bakris GL, Black HR, et al. The Seventh Report of the Joint National
unit: contribution of risk factors. Anesthesiology 1996; 84:772-81.
Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure:
25. Sealy WC, Harris JS, Young WG Jr., et al. Paradoxical hypertension following resec-
the JNC 7 report. JAMA 2003; 289:2560-72.
tion of coarctation of aorta. Surgery 1957; 42:135-47.
8. Goldman L, Caldera DL, Nussbaum SR, et al. Multifactorial index of cardiac risk in
26. Sealy WC. Coarctation of the aorta and hypertension. Annals of thoracic surgery
noncardiac surgical procedures. N Engl J Med 1977; 297:845-50.
1967:315-28.
9. Laslett L. Hypertension. Preoperative assessment and perioperative management.
27. Haas CE, LeBlanc JM. Acute postoperative hypertension: a review of therapeutic
West J Med 1995; 162:215-9.
options. Am J Health Syst Pharm 2004; 61:1661-73; quiz 1674-1665.
10. Prevention of stroke by antihypertensive drug treatment in older persons with isolat-
28. Aronson S, Dyke CM, Stierer KA, et al. The ECLIPSE trials: comparative studies of
ed systolic hypertension. Final results of the Systolic Hypertension in the Elderly Program
clevidipine to nitroglycerin, sodium nitroprusside, and nicardipine for acute hypertension
(SHEP). SHEP Cooperative Research Group. JAMA 1991; 265:3255-64.
treatment in cardiac surgery patients. Anesth Analg 2008; 107:1110-21.
11. Varon J and Marik PE. Perioperative hypertension management. Vasc Health Risk
29. Publication Committee for the VMAC investigators. Intravenous nesiritide vs nitro-
Manag 2008; 4:615-27.
glycerin for treatment of decompensated congestive heart failure: a randomized con-
12. Viljoen JF, Estafanous FG and Tarazi RC. Acute hypertension immediately after
trolled trial. JAMA 2002; 287:1531-1540.
coronary artery surgery. J Thorac Cardiovasc Surg 1976; 71:548-50.
30. Magee LA, Cham C, Waterman EJ, et al. Hydralazine for treatment of severe hyper-
13. Goldberg ME, Larijani GE. Perioperative hypertension. Pharmacotherapy 1998;
tension in pregnancy: meta-analysis. BMJ 2003; 327:955-60.
18:911-4.
31. James DJ. BR. Hydralazine for controlled hypotension during neurosurgical opera-
14. Forrest JB, Rehder K, Cahalan MK et al. Multicenter study of general anesthesia. III.
tions. Anesth Analg 1982; 61:1016-10.
Predictors of severe perioperative adverse outcomes. Anesthesiology 1992; 76:3-15.
32. Kross RA. FE, Leung D, et al. A comparative study between a calcium channel
15. Browner WS, Li J, and Mangano DT. In-hospital and long-term mortality in male
blocker (Nicardipine) and a combined alpha-betablocker (Labetalol) for the control of
veterans following noncardiac surgery. The Study of Perioperative Ischemia Research
Emergence hypertension during craniotomy for tumor surgery. Anesth Analg 2000;
Group. JAMA 1992; 268:228-32.
91:904-9.
16. Singla N WD, Gandhi S, Lumb P et al. Treatment of acute postoperative hypertension in cardiac surgery patients: an efficacy study of clevidipine assessing its postoperative antihypertensive effect in cardiac surgery-2 (ESCAPE-2), a randomized, double-blind,
placebo-controlled trial. Anesth Analg 2008; 107:59-67.
148
NETH J CRIT CARE - VOLUME 15 - NO 3 - JUNE 2011