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SECTION 5
Management of cardiopulmonary
bypass
Section editors:John M.Murkin and Gregory Fischer
23. Management of cardiopulmonary bypass 191
Robert A.Baker, David Fitzgerald, and Robert C.Groom
24. Minimal invasive extracorporeal circulation for
coronary revascularization surgery 205
Kyriakos Anastasiadis and Thierry Carrel
25. Cardioplegia strategies 211
Constantine L.Athanasuleas and Gerald D.Buckberg
26. Patient blood management strategies in
cardiac surgery 217
Aryeh Shander and Victor A.Ferraris
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23
Management ofcardiopulmonarybypass
Robert A. Baker, David Fitzgerald, and Robert C. Groom
Introduction
Coronary artery bypass gra (CABG) surgery utilizing cardiopulmonary bypass (CPB) is the most ecacious management strategy
for diuse ischaemic heart disease. Over the last three decades, surgical revascularization has been challenged by non- surgical, percutaneous interventions including angioplasty and drug- eluding stent
placement in the cardiac catheterization suite and surgical procedures not utilizing CPB, referred to as o- pump (OPCAB) surgery
and procedures using miniaturized circuits to support the circulation. Collectively, all of these innovations were limited in their eectiveness to promote improved outcomes. Percutaneous interventions
(angioplasty and stenting) have been shown to be inferior to surgical
graing on bypass, while o- pump techniques have been demonstrated to purport poorer long- term outcomes, particularly in patients with multivessel coronary disease.
CPB provides the surgical team with the most controlled environment to perform the precise anastomoses needed for a successful
CABG operation. It not only promotes the most stable surgical eld,
but it utilizes a range of techniques that benet both the surgeon
and the patient. is chapter aims to provide the surgical team with
an outline of CPB circuit components and an overview of common
technical issues that diminish the adequacy of perfusion, and to
direct the team to resources available in order to achieve evidencebased clinically safe CPB. is chapter focuses on the utilization of
CPB for CABG surgery; myocardial protection (Chapter25), the use
of mini- circuits (Chapter24), and blood management (Chapter26)
are dealt with in separate chapters.
While mortality and complications related to CPB have declined
over time, numerous observational studies have reported that duration of time on CPB is an independent predictor of stroke, acute
renal injury, and death.– A plausible explanation for this relationship is that longer bypass time increases the opportunity for
exposure to emboli, low blood pressure, and suboptimal organ perfusion. Recent studies examining the relationship between minutes
of exposure to low oxygen delivery and minutes of hypotension
during CPB support this hypothesis., e management of CPB
for CABG must be performed in the context of best practice utilizing evidence- based recommendations where they exist and best
available evidence where recommendations are lacking, coupled
with experience and good clinical judgement.– Moreover, communication between the surgeon and perfusion team is paramount
for obtaining safe and optimal support. Finally, CPB must be reported accurately and the quality of practice continuously improved.
Clinical equipoise clearly exists in some aspects of the management
of CPB. e discovery of improved processes of perfusion support
that result in measurable improvements, such as reduction in rates
of new heart failure, acute kidney injury, postoperative intensive
care, and death, have produced better clinical outcomes in an increasingly complex and patient- centred health system. Globally, individuals older than 65years of age are among the fastest growing
demographic, resulting in predictions that the proportion of people
aged 65– 74years will increase by 65% from 2010 to 2025, presenting
cardiac surgery with a very signicant increase in the population
potentially at risk of heart disease.
Technology forcardiopulmonarybypass
Pumps
e technology available for conventional CPB for CABG is continually evolving. e heart– lung machine provides the backbone
for CPB. e choice of arterial pump remains primarily cost driven,
with the most recent meta- analysis not demonstrating any signicantly dierent haematological or clinical outcomes between
roller and centrifugal pump systems. Roller pumps (or peristaltic
pumps) work via positive displacement by occluding tubing between a stationary raceway and rotating roller(s) or occluder(s).
Blood is pushed ahead of the moving rollerhead and the squeeze
of the occlusion against the raceway. Pump ow to the patient is
a calculated value, determined by the length and diameter of the
tubing inserted through the rollerhead raceway, and the revolutions
per minute. Standard safety features in modern roller pump design
include emboli and uid level servo regulation of ow, a modular
construction that permits rapid pump exchange, and battery backups and manual hand cranks in the event of power failure. Concerns
with roller pumps relate to the variability of the occlusiveness of
the arterial pump, contributing to haemolysis (with over- occluded
roller pumps) and retrograde ow (with under- occluded roller
pumps), cavitation of air dissolved in solution, and the generation of
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particulate emboli in the inner surface of the tubing from excessive
interaction with the rollerhead (spallation). While reports of tubing
rupture in the arterial raceway are rare, the likelihood may be increased through other factors, such as the diameter of the tubing,
temperature, and prolonged CPB support.
Centrifugal (constrained vortex) pumps are aerload dependent,
moving blood by the addition of kinetic energy through the forced
centrifugal rotation of an impeller or cone within a constrained
housing. Blood ow is directly related to resistance, therefore unexpected increases in resistance will result in a ow reduction or cessation. Introduction of air into these pumps will de- prime the pump
reducing the likelihood of massive air embolization; however, small
quantities of air, if aspirated into the pump head, may coalesce and
be passed into the outlet stream of uid movement, and into the
patient. Haemolysis remains a concern with centrifugal pump; however, they do not produce mechanical trauma to the extracorporeal
tubing. A potential complication associated with non- occlusivetype pumps involves retrograde ow through the aortic cannula
when the pressure in the central aorta exceeds that generated by
the pump. Retrograde ow through the circuit can be attenuated
with additional safety equipment including one- way valves, lowow alarms, and zero- balance pump ow revolutions per minute.
Generally, centrifugal pumps produce less blood damage; however,
this improvement may be inconsequential given the blood trauma
and inammation related to contact activation of the blood related
to cardiotomy suction, the introduction of gaseous and particulate
emboli, the surface area of the extracorporeal circuit, and related
factors. e use of centrifugal pumps is currently supported by the
Society of oracic Surgeons/ Society of Cardiac Anesthesiologists
(STS/ SCA) recommendation ‘It is not unreasonable to select a
centrifugal pump rather than a roller pump but more so for safety
reasons rather than blood conservation’.
e heart– lung machine supports auxiliary pumps for cardioplegia
delivery, intracardiac venting, cardiotomy suction, ultraltration,
and dialysis. ese auxiliary pumps may consist of rollerheads of
varying size and conguration. Aschematic of the equipment and
circuit for CPB is shown in Fig. 23.1. All pump systems are equipped
with an uninterrupted power source installed to provide battery
back- up during operating room power failure. Manual hand cranks
should all be standard to all pumps and immediately available for
mechanical drive motor or console failure.
Circuitry
Disposable devices are coupled to the framework of the heart–
lung machine (oxygenator, tubing, cannulae, cardioplegia delivery
system) to provide an environment that not only supports the
patient’s native heart and lung function, but presents the surgical
team with a quiet and bloodless surgical eld.
Evidence supports the choice of some technologies used for CPB;
however, genuine clinical equipoise oen exists within the range
of technology provided by industry requiring ongoing support
for perfusion- related research. e use of membrane oxygenation
systems, arterial line ltration, and biocompatible coatings are the
standard of practice. e introduction of the hollow bre mem-
for a prolonged duration of support. e continued improvements
in hollow bre membrane size and design have enabled clinicians
to move away from the ‘one- size- ts- all’ concept and towards
more customized patient size- specic and prescriptive strategies.
Manufacturers now provide support to meet diering demands, for
example, to meet the high blood ow demands of large body mass
index patients, be it by dierent sizes of oxygenator or by increasing
the range of ow speciations for dierent devices. e incorporation of arterial line ltration into the oxygenator (‘integrated’) has
simplied the set- up for CPB and aided in reducing surface area and
static prime volume. e use of arterial line ltration has been accepted as a classI, level Arecommendation. Numerous studies in
vitro and in vivo have evaluated the gaseous microemboli handling
of both integrated and stand- alone arterial line ltration and oxygenator systems and choice must be based upon both clinical performance characteristics and safety features, such as a lower embolic
load than the device being replaced., e use of biocompatible
tubing is recommended for blood conservation benets (classIIB,
level A) and for the attenuation of the inammatory response
(classIIA, level B); however, equipoise exists pertaining to which
type of biopassive surface should be used and the extent of how
much articial surface is covered on the CPB circuit.
e benets of other components of the bypass circuit are less
well reported and their use may be determined at a local level.
Murphy etal. reported the perceived advantages and disadvantages
of collapsible ‘closed’ shell versus hard ‘open’ shell venous reservoir systems; however, there is no clear evidence supporting the
use of either system. e importance of understanding the equipment and the materials being used in the CPB circuit cannot be
overstated. Subtle changes to tubing and oxygenator design have
previously been implicated in operating room accidents and near
misses. In 2017, concerns were raised with the type of material used
to build the heat exchanger component of the oxygenator, as heat
exchange with polymer membranes separating the blood and water
components were implicated in the transfer of hydrogen peroxide
to patients.
e decision for which technology is adopted must critically balance functionality, safety, experience, outcome, and cost. e ability
to balance each of these factors distinguishes high- performing clinical teams. e choice of both arterial and venous cannulas is an
example of these competing inuences. Surgical factors such as
exibility, feel, size, and ease of handling need to couple with ow
characteristics including direction, dispersion, pressure gradients,
and eect on rheology. Designs for arterial cannulas aim at optimal ow (maximum) to minimize the pressure gradient across
the cannula to less than 100mmHg, at arterial line pressures of less
than 250mmHg. Collectively, arterial cannula design, coupled with
matching of the size of cannula and the patient, aim to reduce the
likelihood of turbulence and cavitation due to high pressures and
ows and reduce the risk of aortic wall damage due to high ow
directly into the aortic wall. Venous cannulas signicantly inuence venous drainage. Dual- stage cannulas with gravity drainage
provide the mainstay for CABG surgery. When reduced drainage is
encountered due to the inability to use large enough cannulas, then
augmented venous return must be considered. Vacuum- assisted
compact device which meets the demand for clinical oxygen (O)
transfer and carbon dioxide (CO) removal, reduced prime volume,
decreased pressure drop, and minimized haematological damage
venous drainage is popular; however, the risk associated with air entrapment and emboli generation associated with excessive negative
pressure must be considered.
23 Management ofcardiopulmonarybypass 193
Meter
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Systemic Flow Line
Cross Clamp
Flow Meter
Blood Gas
Monitor
Air Bubble Detector
(optional position)
Anti-Retrograde
Flow Valve (with
Centrifugal
Pump)
Arterial
Filter and
Bubble
Trap
One Way
Valve
Venous
Blood
Sensor
Electronic
Venous
Occluder
Arterial
Blood Gas Sensor
Sampling
Manifold
Level Sensor
Gas Filter
Gas In
Gas Out
Cardioplegia Delivery Line
Aortic Root Suction
Cardiotomy Suction
Left Ventricular Vent
One-Way
Valve
Cardiotomy
Reservoir
Filter
Membrane
Recirculation
T
Venous
Reservoir
T
Line
High
K+
Cardioplegic
Vent Suction Suction
Air Bubble
Detector
Sensor
Systemic
Blood
Pump
Pressure
Solution
PT
Low
K+
Blood
Cardioplegia
Pump
Flowmeter
(With Centrifugal Pump)
Heat
Exchanger
Bubble Trap
Temperature
Cooler
Heater
Water Source
P
Pressure
To Scavange
Oxygen
Analyzer
Anesthetic
Vaporizer
Gas
Flow
Air
Oxygen
Blender
Fig.23.1 Diagram of the components of the CPB circuit. Detailed schematic diagram of the arrangement of a CPB circuit using a membrane
oxygenator with integrated hard- shell venous reservoir and systemic heat exchanger, with an external cardiotomy reservoir (more commonly this is
fully integrated in hard- shell reservoirs). Venous cannulation is depicted in the right atrium and extending towards the inferior vena cava and arterial
cannulation in the ascending aorta. The systemic blood pump may be either a roller or centrifugal type. The cardioplegia delivery system (right) is a
one- pass combination blood/ crystalloid type. The cooler- heater water source may be operated to supply water independently to both the oxygenator
heat exchanger and cardioplegia delivery system. Some circuits do not incorporate a membrane recirculation line; in these cases, the cardioplegia
blood source is a separate outlet connector built into the oxygenator near the arterial outlet. Safety features include the air bubble detector sensor
which may be placed on the line between the venous reservoir and systemic pump (shown in red), or between the pump and membrane oxygenator
inlet, or between the oxygenator outlet and arterial filter (neither shown), or on the line after the arterial filter (optional position on drawing). Areservoir
level detector is shown attached to the housing of the hard- shell venous reservoir. An ultrasonic flowmeter distal to shunts provides an accurate
measure of patient flow. Aone- way valve, to prevent retrograde flow with a centrifugal arterial pump, is shown on the systemic flow line. Other safety
devices include an oxygen analyser placed between the anaesthetic vaporizer (if used) and the oxygenator gas inlet. Arrows indicate direction of
flow, bright red depicts arterial blood flow, blue venous blood flow; X, placement of tubing clamps; P and T (within circles), pressure and temperature
sensors, respectively.
Reproduced from Hessel, Eugene AII, 2008, “Circuitry and Cannulation Techniques”. In Cardiopulmonary Bypass:principles and practices. Edited by Gravlee GP etal. Third Edition,
Philadelphia, Lippincott, Williams and Wilkins with permission from Wolters Kluwer.
e lack of denitive data to dictate the selection of some components of the circuit results in enormous variation between centres
while producing seemingly similar clinical outcomes. Registry data
from the STS Cardiac Surgical Database, the PERForm perfusion
registry, and the Australian New Zealand Collaborative Perfusion
Registry (ANZCPR) challenge this view as they demonstrate
enormous variation in outcomes in part inuenced by the choice of
components used in the CPB circuit.
Monitoring, safety, and electronic perfusionrecords
Safety systems (positive and negative pressure regulation, ow, low
reservoir level, bubble), integrated reporting systems (pressures,
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ow, temperature), and continuous inline blood gas monitoring devices provide the perfusionist with an environment to conduct safe
CPB. All heart- lung machines include a microprocessor- controlled
safety interface with their pump consoles. ese systems monitor
and control pump function and serve as the primary mechanical
safety control system for regulating extracorporeal ow, allowing
servo regulation for preset pressure limits and may consist of earlywarning alarms that alert the user to events such as changes in arterial
line pressures or venous reservoir levels, or they respond to abrupt
changes, such as increases in pressure, or microbubble activity, and
will automatically turn o a pump when preset limits are exceeded.
Electronic perfusion records can serve as the conuence to merge
safety monitoring data with clinical information generated in the
operating room. Physiological patient data from the anaesthesia and
perfusion monitoring devices and output data from the heart– lung
machine and peripheral equipment (e.g. inline blood gas analysers,
coagulation devices, heater/ cooler units, and regional oximetry
monitors) can be integrated into a single point- of- care source that
displays and stores essential clinical data during and aer the surgical procedure. e electronic perfusion record provides valuable,
continuous real- time monitoring of both arterial and venous saturation values used to calculate essential perfusion parameters such
as oxygen delivery, oxygen consumption, and venous CO values.
is provides the clinician with additional information by which to
customize the delivery of care to the patient. It also oers the opportunity for supporting decision- making in real time, from simple reminders (e.g. to measure activated clotting time (ACT), cardioplegia
intervals), to more complicated integrated decision algorithms (e.g.
pharmacological intervention). Further, new- generation electronic
perfusion record solutions now oer continuous critical care parameter compliance monitoring to not only improve clinician response
time during support, but to quantify, in duration, the patient’s exposure to conditions outside of departmental clinical compliance
protocols. At the conclusion of the surgical procedure, automated
and manually inputted data collected during CPB are incorporated
into the electronic perfusion perioperative record, which can be uploaded to a secure server and used for quality assurance and improvement activities.
accepted target ow rates of 2.2– 2.4 L/ min/ m at normothermia,
with reductions in ow corresponding with patient hypothermia,
have been the standard; however, evidence for such practices lack
scientic support. Similarly, there is much variation in pressure
management. e range for normal cerebral autoregulation has
consistently provided a basis for maintaining pressure in the range
of 40– 80mmHg. Ongoing work from researchers at Johns Hopkins
University (Baltimore, MA, USA) continue to explore the relationship between pressure and optimal perfusion using cerebral oximetry to assess cerebral perfusion. e recent trial by Vedel et al.
failed to show dierences between a high- target (70– 80 mmHg)
and low- target (40– 50mmHg) perfusion pressure strategy with respect to cerebral infarction. e recently published randomized
Goal Directed Perfusion trial has continued to focus attention on
the balance of oxygen delivery and consumption and emphasizes
the balance between ow, haemoglobin concentration, and oxygen
saturation and the importance of maintaining oxygen delivery
(DO) above a critical value to reduce the likelihood of kidney injur y. e current evidence on DO and carbon dioxide production
(VCO) suggests that calculated DO levels should be maintained
above 260– 280 mL/ min/ m. e evidence supporting maintaining
a ratio of DO/ VCO greater than 5 is limited. Further research
is needed to validate these values in relation to patient outcomes.
To achieve these indices, the arterial pump ow and the haemoglobin concentration provide the signicant modiable factors for
the surgical team.
e use of pulsatile bypass has been extensively studied. Some
have reported benecial eects at both the cellular and microvascular levels and with clinical outcome benets; however, other
reports have not supported these ndings. e major issue underlying the evaluation of pulsatility and bypass has been the ability to
generate a physiologically signicant pulsatile wave. Arecent metaanalysis of the use of prophylactic intra- aortic balloon pump in high
risk CABG patients reported a reduction in perioperative and 30day mortality. ese data further support continued investigation
of the possible role of pulsatile perfusion in routine clinical management. Observational data from clinical registries may to help drive
the demand for prospective randomized controlled trials to evaluate
this topic.
Techniques forcardiopulmonarybypass
CPB techniques vary enormously and such details can directly impact long- term patient outcomes. High- performing clinical teams
incorporate best practices by balancing experience, scientic evidence, and clinical guidelines to develop local protocols. When
coupled with data collection and imbedded quality improvement,
these protocols ensure the ongoing improvement of patient care and
outcome.
Ideal perfusion support has not been clearly dened. Guidelines
and recommendations for some aspects have been published– and
other practices can be supported by research and consensus, collectively providing support for the development and implementation of
institutional protocols.
Flow, pressure, and oxygendelivery
Best practice currently targets blood ows and haemodynamic
pressures to meet the metabolic needs of the patient. Commonly
Avoidance ofemboli
Methods to avoid microbubble generation and transmission
from the CPB circuit must be implemented. e association
of microbubbles and poor outcomes has been demonstrated.
Manufactures have engineered oxygenator and lter design to reduce or minimize generation of microbubbles. More recent literature has reported variation between dierent devices and the
ability to handle embolic loads in laboratory and clinical situations.
e characteristics of emboli handling must be considered when
each component of the CBP circuit is selected, and when surgical
eld venting and suction is utilized. e use of cardiotomy suction for retrieval of shed blood pooling outside of the pericardium
may introduce liquid fat emboli from the subcutaneous tissue and
sternum to the CPB circuit. e liquid composition of the fat facilitates passage through the ltration mechanisms of the circuit
and can emulsify in the distal circulation of the patient. e presence of brain lipid emboli was identied in a canine model when the
use of cardiotomy suction was employed. Peer- reviewed literature
23 Management ofcardiopulmonarybypass 195
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has questioned the indiscriminate use of cardiotomy suction during
CABG surgery. Alternative strategies for blood conservation and
recovery can be performed to avoid the deleterious eects of pump
suction.
Perfusion techniques during CPB are important in reducing the
embolic load, including reducing perfusion interventions (such as
introducing air emboli with drug and uid administration), eliminating the entrainment of air into the venous line both by appropriate xation and removal of air prior to establishment of bypass,
and the use of electronic venous line occluders to reduce venous air
entrainment. e addition of cerebral embolic protection devices
(lters) received some early support; however, the most recent randomized controlled trial of these devices has shown them not to signicantly impact cerebral infarction.
Temperaturemanagement
Clinical practice guidelines for temperature management during
CPB were published in 2015, providing clinical teams with guidance for temperature monitoring and practice. CABG surgery is
now commonly performed with mild hypothermic or tepid bypass
(30– 34°C). Particular attention must be given to surrogate measures
for cerebral perfusate temperature (arterial outlet temperatures), the
avoidance of hyperthermia, and the rate of rewarming. As an acceptable surrogate to cerebral temperature, the arterial outlet blood
temperature should not be permitted to exceed 37.0°C (classI, level
of evidence C). However, the design of the arterial temperature
monitoring probe may result in an underestimation of the true temperature by as much as 0.67°C. ese aws in the accuracy of the
measurement stress the importance of avoiding even mild degrees
of hyperthermia.
Blood gasmanagement
Alpha- stat pH management for CABG as recommended by Shann
etal. for patients undergoing CPB with modest hypothermia is the
mainstay of CABG pH management and has not been challenged in
recent times.
Avoidance ofanaemia
Anaemia on bypass has been reported to be detrimental to patient outcome. Blood conservation clinical practice guidelines for
cardiac surgery recommend that the entire cardiac surgical team
should ensure all consideration is given to avoiding reducing the
patient’s haematocrit during bypass. Circuit volume minimization to reduce priming volume is one technique for helping opti-
aim for intraoperative management is to maintain near- normal
serum glucose values during bypass. ese recommendations
suggest that monitoring glucose during bypass is essential in all
patients. Current literature is challenging managing elevated glucose levels the same for both diabetic and non- diabetic patients,
with intensive care unit literature suggesting that the target glucose levels for diabetic patients and non- diabetic patients may
dier. e recent Intensive Versus Conservative Glucose Control
in Patients Undergoing Coronary Artery Bypass Gra Surgery
(GLUCO- CABG) trial indicated that there was no observed
benet demonstrated in diabetic patients who received intensive
glucose management compared to non- diabetic patients in whom
a signicant benet was realized. e authors suggested that diabetic patients who were hyperglycaemic may not do better if their
glucose is aggressively managed. More research on this topic is
needed.
Other areas ofmanagement
Some areas of management have no clear directions from the literature, most notably the choice of prime. Crystalloid primes (e.g.
Plasma- Lyte®, Ringer’s solution, Hartmann’s solution) provide the
majority (by volume) of priming solutions. Registry data (PERForm
and ANZCPR) and survey data demonstrate a wide variation in
priming solutions and additives used for CPB. Local protocols dening practice can reduce variation within institutions and practice
groups.
Common haemodynamic problems during
cardiopulmonarybypass
Early recognition and mitigation of conditions that interfere with
adequate tissue perfusion during CPB protect the patient from injury. Problems related to cannulation and positioning of the heart
to gain exposure to target coronary artery vessels on the posterior
surface of the heart may interrupt systemic blood ow, resulting in
venous or cardiac congestion. ese problems oen present as a low
reservoir volume, reduced systemic blood ow, and hypotension.
Blood loss to plural spaces or excessive use of a discard suction or
cell saver suction may also contribute to reduced blood ow rate.
Table 23.1 lists some of these common problems, their aetiology,
and practical mitigation strategies. Communication between the
surgeon and perfusionist regarding the adequacy of perfusion, particularly at the initiation of CPB and when the heart is positioned
or retracted to perform posterior distal coronary anastomoses, is
essential.
mize uid balance during CPB support to minimize haemodilution.
Acute normovolaemic haemodilution, retrograde autologous
priming, vigilant uid management, and autotransfusion recovery
systems all work to preserve the red cell mass of the patient. e
Assessing and supporting evidence- based
practices forcardiopulmonarybypass
incremental benet of each of these techniques results in much
higher bypass haemoglobin level on bypass when utilized together.
See Chapter26 for a detailed discussion of blood management in
CABG surgery.
Glucosemanagement
Guidelines for the glucose management for CABG were published
by the STS/ SCA for adult cardiac surgery in 2009. Currently,
the recommendations focus on glucose level management dichotomized at 180 mg/ dL and diabetic status of the patient. e
The technologies and practices of CPB for CABG described
previously demonstrate the need for perfusion teams to under-
stand the requirement to practise in a manner that leverages
the best available knowledge available and to supplement best
evidence- based perfusion with experiential- based practices
through the development of rigorous institutional protocols to
provide clinical teams and patients with the most rigorous per-
fusion standards. Medical practice currently has invested in the
use of evidence- based clinical practice guidelines. In CABG
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Table23.1 Common haemodynamic problems duringbypass
Problem Aetiology Corrective action
Poor venous return Excessive retraction of the heart Reposition the heart
Kink or obstruction of venous tubing Check venous line from cannula to venous reservoir
Air lock in venous line ‘Walk’ the air lock out of venous line, or clamp and refill venous line
Pressurized venous reservoir Vent the venous reservoir to atmosphere
Malposition of venous cannula Reposition venous cannula
Inadequate cannula size Replace cannula, add second cannula or use VAVD
Low blood volume Loss of circulating volume Administer volume
Loss of blood to pleural spaces Replace or if excessive return blood to circuit using pump suction
Loss of blood to discard or cell saver suction Replace lost volume and if loss is excessive use pump suction
Undetected blood loss (circuit or operating table) Detect source of blood loss and correct
Low systemic vascular resistance due to ongoing
vasodilator use
High circuit line
pressure
Cardiac distension Obstructed venous cannula Reposition venous cannula
Low venous blood
saturation
Low arterial blood
pressure
Malposition of the arterial cannula Cannula tip directed toward aortic valve, cannula tip selectively placed in
Obstruction in the circuit or blood oxygenator Examine the circuit for kinked lines and assess oxygenator pressure gradient
Incorrect arterial cannula for patient If excessive consider recannulation
Selective cannulation of hepatic vein Reposition venous cannula and examine position with TOE
Aortic insufficiency Vent the left ventricle
Undiagnosed patent ductus arteriosus Identify and ligate patent ductus arteriosus
Other aortic to pulmonary shunt Identify and control aortic to pulmonary shunts
Inadequate cannula size Replace cannula, add second cannula or use VAVD
Low blood flow Add volume, assess venous drainage, and increase flow rate
Low haemoglobin level Increase oxygen deliver with RBC transfusion or haemofiltration
Poor oxygenator function Increase FiO2, inspect circuit for shunts, check gas supply, replace oxygenator
Undersedation and analgesia Increase depth of sedation with pharmacological agents
Shock Administer vasopressor
Malpositioned arterial cannula Reposition cannula
Oxygenator or other shunt open Close arterial to venous shunts
Loose roller pump occlusion or calibration Adjust occlusion or calibration factor
Cease vasodilators
arch vessel
if increasing FiO2 does not work
TOE, transoesophageal echocardiography; VAVD, vacuum- assisted venous drainage.
surgery, the guideline published in 2011 had few CPB- related
actions; more recently, the STS published blood management
guidelines which provide direction for clinical teams (currently
under revision), as does the work of the Perfusion Task force of
the STS, the SCA, and the American Society of Extracorporeal
Technology (AmSECT) which has published clinical practice
guidelines on temperature management and anticoagulation,
and is working towards additional documents.,, Professional
groups including AmSECT, the Society of Clinical Perfusion
Scientists and the College of Clinical Perfusion Scientists
of Great Britain and Ireland, and the Australian and New
Zealand College of Perfusion have developed standards and
guidelines to help clinical teams develop strategies to support
evidence- based clinical practices. Recently, a task force of surgeons, anaesthesiologists, and perfusionists from the European
Association for Cardio- Thoracic Surgery, European Association
of Cardiothoracic Anaesthesiology, and the European Board of
Cardiovascular Perfusion published evidence- based guidelines
for CPB, comprising 113 recommendations. Tables23.2– 23.5
summarize the recommendations by classification of evidence
and cross reference these guidelines with other published standards and clinical guidelines. Collectively, these documents
provide the strongest opportunity for the improvement of CPB
practices.
Table23.2 ClassIrecommendations fromEACTS/ EACTA/ EBCP compared tosimilar statements fromreferenced documents
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19723 Management ofcardiopulmonarybypass
ClassI
EACTS/ EACTA/ EBCP Guidelines
Part III. Training, education and service delivery
It is recommended that perfusionists complete
a formal period of training in an approved
educational training programme.
It is recommended that perfusionists achieve
certification by successfully completing an
examination of skills and knowledge. The
certification shall be maintained by the
demonstration of an appropriate level of
continued professional development, minimum
caseload and professional standards.
It is recommended that perfusion departments
are structured around a quality management
framework approved by the institution.
It is recommended that each perfusion
department has written standard operating
procedures for the conduct of CPB.
It is recommended that the perfusion
department is adequately staffed, equipped and
resourced.
It is recommended that verbal communication
between team members in the operating room
is standardised and always acknowledged.
Reporting and systematically analysing errors
or untoward events, including outcomes
dissemination for shared learning, is
recommended.
Part IV. Heart– lung machine hardware
It is recommended that pressure monitoring
devices are used on the arterial line and
cardioplegia delivery systems during CPB.
A bubble detector is recommended during CPB
procedures on all inflow lines.
It is recommended to use a level sensor during
CPB procedures utilising a (hard- shell) reservoir.
It is recommended to have backups for vital
systems of the heart– lung machines available at
all times.
It is recommended to have a maintenance plan
for CPB equipment.
Continuous arterial line pressure monitoring
(pre- and postoxygenator) in the CPB circuit is
recommended.
Continuous oxygenator arterial outlet
temperature monitoring is recommended.
It is recommended to continuously monitor
SvO2 and HCT levels during CPB.
Monitoring of blood gas analyses through
regular intervals or continuous observation is
recommended during CPB.
It is recommended to objectively report,
adequately record and properly analyse all
adverse events related to CPB practice in an
efficient and timely manner.
It is recommended that continuous piped
supplies of oxygen, air and carbon dioxide
are delivered and controlled during CPB with
backup cylinder supplies available.
Level of
evidencea
C Y
C Y
C Y
C Y
AmSECT 2017
S&G (1)
S2.1
S2.1
S17.1
S1.1
ANZCA (2) GB&I (3) Safety AHA/
Y
1.2, 3.2
Y
3.2
Y
3.1
Y
3.2
Y
3.3.2
Y Y
13.1
C Y S15,16.1 Y Y 10.1, 10.2
C Y
S3.1, 3.2
C Y
Y
5.2.3.4
3.3.3
Y
15.0
C Y
S6.1, 7.2, 7.4Y4.2.5.1
C Y
6.2
C Y
6.3
C Y
S18.4
C Y
S18.2
C Y
S.2 (Post)
C Y
S6.4
B Y
S7.7, 7.10
C Y
Y
4.2.6
Y
4.2.4.1
Y
4.2
Y
4.1
Y
4.2.5.1
Y
4.2.8.4
Y
4.2.7.1
Y
S 7.6
C Y
3.3.3
C Y
S6.10
Y
4.2.2
ACC(4)
Y
Y
ClassI
Level C
ClassI
Level B
ClassI
Level C
STS/ SCA/
AmSECT
(5,6,7)
ClassIIa
5
Level B
ClassI
6
Level C
5
(continued )
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