Transcript Monitoring

The Case :
A 68-year-old woman with multiple cardiac
risk factors had sudden onset of crushing
substernal chest pain.
Despite aggressive thrombolytic therapy, the
patient had electrocardiogram (ECG) evidence
of a transmural anterolateral myocardial
infarction (MI).
Three weeks following the MI, the patient
develops acute cholecystitis, and presents for a
cholecystectomy.
QUESTIONS
1.How do you evaluate the cardiac risk in a patient
scheduled for noncardiac surgery?
2.What is the cardiac risk in this patient? What
additional investigations should be performed?
3.What are the implications for anesthetic
management when coronary revascularization is
performed before noncardiac surgery?
QUESTIONS
4.What intraoperative monitors would you use?
5.What additional
prepared?
drugs
would
you
have
6.What anesthetic technique would you use?
7.How would
postoperatively?
you
manage
this
patient
How do you evaluate the
cardiac risk in a patient
scheduled for noncardiac
surgery?
Preoperative Cardiac Evaluation
The cornerstone of preoperative cardiac
evaluation includes
Review of history
Physical examination
Diagnostic tests
Knowledge of the planned surgical procedure.
Preoperative Cardiac Evaluation
Preoperative Resting Electrocardiogram
Is readily available, inexpensive, easy to perform
and able to interpret and detect previous
myocardial infarction, acute ischaemia, or
arrhythmias.
The presence of abnormalities such as Q waves
and non sinus rhythms has been shown to
correlate with adverse postoperative cardiac
events.

Stepwise approach to preoperative
cardiac assessment
What is the cardiac risk in this
patient?
What
additional
investigations
should
be
performed?
Perioperative cardiac risk:
Pt factors: major risk (recent MI)
Surgical factors: major intraperitoneal
surgery is an intermediate risk.
Additional Tests
Stress tests
 Exercise stress test
 Pharmacological
Dobutamine stress echocardiography.
Dipyridamole thallium scintigraphy.
Additional Tests


Preoperative coronary angiogram /
coronary intervention:
The decision for or against preoperative
angiogram,
coronary
revascularization,
percutaneous interventions (PCI) or coronary
artery bypass grafting (CABG), should be based
entirely on universally accepted medical
indications for coronary revascularization and
the appropriate technique.
Coronary angiography in this case is class (I)
According to ACC/AHA guidelines for PCI after thrombolysis,
as formation of Q waves in ECG after thrombolysis is
considered an evidence of ischemia.
What are
anesthetic
coronary
performed
surgery?
the implications for
management
when
revascularization
is
before
noncardiac
Anesthetic implications of
revascularization



Prophylactic coronary revascularization in
patients with asymptomatic CAD before major
surgery has no benefit.
Revascularization by CABG or PCI must be
justified according to long term outcome.
PCI- angioplasty is now often accompanied by
stenting
which
require
post
procedure
antiplatelet therapy to prevent acute coronary
thrombosis.
Recommendations for timing of non-cardiac surgery after PCI. PCI=
percutaneous coronary intervention
Anesthesiology 2008;109:596–604
Anesthetic implications of
revascularization



So if BMS to be inserted elective surgery is
recommended to postpone for 6-8 wks.
If DES to be inserted, elective surgery is
recommended to be postponed for at least 12
months.
Revascularization by CABG, postpone elective
surgery for 3-6 months.
What intraoperative
monitors would you use?
Monitoring

•
An important goal of when selecting
intraoperative monitors for patient with
ischemic heart disease is select those that
allow early detection of myocardial ischemia.
Electrocardiography the simplest, most cost
effective method to detect myocardial ischemia
by focusing changes in ST-segment changes;
Monitoring
•
•
•
ST-segment changes; such as depression or
elevation of at least 1mm.
The degree of ST segment depression parallels
the severity of myocardial ischemia.
Visual detection of ST segment IS unreliable,
computerized ST segment analysis has been
incorporated in electrocardiography monitor.
Traditionally, monitoring two leads, II and V5
has been standard.
•The lead sensitivity in detecting myocardial Ischemia is displayed,
•The combination of lead II and V5 Provides the greatest ability to
detect ischemia and Rhythm disturbances.
Intraoperative monitors

Pulse oximetry ( to assess arterial oxygenation).

Invasive blood pressure (for early detection of

Capnography (to determine continual end-tidal CO2

Body
hemodynamic instability)
analysis specially if laparoscopic cholecystectomy was
the selected procedure)
temperature
(to avoid intraoperative
hypothermia which predispose to shivering on
awaking, leading to abrupt increase in oxygen
consumption )
Intraoperative monitors

Urine output : using Foley`s catheter.

PAC: a number of studies reported that PAC is an

TEE by detection of new wall motion abnormality. It's
insensitive monitor for myocardial ischemia and should
not be inserted for this as a primary indication.
use here is not beneficial as it must be inserted after
induction and removed before extubation, thus missing
the critical time of hemodynamic changes, also deep
gastric views will interfere with the surgical field.
Q5:What additional drugs
would you have prepared?
Drugs used in treatment of intraoperative
myocardial ischemia must be available, and
treatment should be instituted when there are 1
mm ST segment changes on ECG.
 Aggressive
pharmacological treatment of
changes in heart rate and/or blood pressure is
indicated.


A persistent increase in heart rate:
can be
treated by intravenous administration of beta
blocker such as esmolol.
Q5:What additional drugs
would you have prepared?


Nitroglycerine is more than appropriate when
myocardial ischemia is associated with normal or
elevated blood pressure. Nitroglycerine induce
coronary vasodilation and decrease in preload
facilitate improvement of subendocardial blood
flow.
Sympathomimetic drugs must be available to
treat hypotension to restore coronary perfusion
pressure, also fluid infusion can be usful to help
restore blood pressure.
Q6:What anesthetic technique would
you use?

1.
2.
The basic challenge during anesthesia in
patient with ischemic heart disease are
To prevent myocardial ischemia by optimizing
myocardial oxygen supply and reducing
myocardial oxygen demand.
To monitor for ischemia and to treat ischemia
if it develops.
Q6:What anesthetic technique would
you use?



So avoid tachycardia as it increase oxygen
requirements and decrease the diastolic time
and thus the coronary blood flow.
Avoid hyperventilation, because hypocapnia
may cause coronary artery vasoconstriction.
Intraoperative events associated with systolic
hypertension, arterial hypoxemia, hypotension
can adversely affect patients with ischemic
heart.
Laparoscopic versus open
cholecystectomy


The main hemodynamic alterations during
laparoscopy is increase in systemic vascular
resistance slight decrease in the cardiac
output
which
proportionate
with
intraperitoneal pressure.
For those patients postoperative benefits of
laparoscopy must be balanced against
intraoperative risk when choice laparoscopy
versus laparotomy.
Laparoscopic versus open
cholecystectomy

Over the past years , patient with
progressively more severe cardiac disease
have safely undergone laparoscopy. Because
of improved knowledge of hemodynamic
repercussions of pneumoperitoneum.
Laparoscopic versus open
cholecystectomy

1.
2.
3.
4.
5.
So if laparoscopy is used
Slow insufflation.
Low intraabdominal pressure.
Hemodynamic optimization before
pneumoperitoneum.
Patient tilt after insufflation.
Vasodilator drugs and sympathomimetic
drugs must be available.
Anesthetic technique.


The laparoscopic cholecystectomy can be
performed safely under spinal anesthesia as
the sole anesthetic procedure and also
showed the superiority of spinal anesthesia in
postoperative pain control compared with the
standard general anesthesia.
Also laparoscopic cholecystectomy has been
reported performed under thoracic epidural
anesthesia in patient with respiratory disease.
Segmental thoracic spinal anesthesia


A new technique introduced by Van Zandert in 2006,
a case report of laparoscopic cholecystectomy in a
patient with severe respiratory lung disease. 1 ml
plain bupivacaine plus sufentanil 2.5 µg (0.5 ml)
injected intrathecally at the level of 10 th thoracic
interspinous space.
Within 3 min a segmental sensory (pinprick) block,
extending between the third thoracic and second
lumbar dermatomes, was obtained, but without any
motor weakness in the legs or hint of respiratory
distress.
Segmental thoracic spinal anesthesia
Mean arterial pressure changes
Group I
Group II
120
100
80
h.
A
ft
er
4
h.
A
ft
er
3
h.
A
ft
er
2
h.
A
ft
er
1
n
io
In
ci
s
In
d
uc
t io
n
60
40
20
0
Pr
e

Segmental thoracic spinal anesthesia

Postoperative pain
Group I
Group II
6
5
4
3
2
1
0
After 2h.
-1
After 4h.
After 12h.
After 24h.
Postoperative management



The postoperative period appears to present
the highest risk for cardiac morbidity and
mortality.
During this period, 67% of the ischemic
events occurs.
This period characterized by increase in heart
rate, blood pressure, sympathetic discharge
and hypercoagulability.
Postoperative management

Postoperative myocardial ischemia occurs in
about 33% of high risk patient.

Most of Those events (50%) are silent.

Most cardiac events occurs in the first 48
hours postoperatively, delayed cardiac events
can occur.
Postoperative management

1.
2.
3.

The goals of postoperative management are
the same as intraoperative management
Prevent ischemia
Monitor ischemia
Treat ischemia
Shivering, pain, hypoxemia, hypercarbia,
sepsis and hemorrhage lead to increased
oxygen supply / demand imbalance which in
turn precipitate myocardial ischemia.
Postoperative management



Effective pain management is essential to
prevent adverse outcomes.
PCA and PCEA are the most effective.
Effective pain management leads to a
reduction in postoperative catecholamine
surge and hypercoagulability.
Postoperative management


Patient with ischemic heart disease is
adversely affected by anemia. Evidence
suggest that transfusion are rarely beneficial
if hemoglobin level exceeds 10 gm%.
Avoid
postoperative
hypovolemia.
hypothermia
and
Postoperative management

Measurement of biomarkers of cardiac
injury.
Cardiac specific Troponin I and T is the preferred
marker due to high sensitivity.

They are normally not present in the
plasma so high signal to noise ratio.