This document
is available on the following websites:
Society of
Clinical Perfusion Scientists of Great Britain & Ireland
www.scps.org
Association of Cardiothoracic Anaesthetists
www.acta.org.uk
Society of Cardiothoracic Surgeons of Great Britain & Ireland
www.scts.org
Introduction
The aim of this document is to determine standards of monitoring during cardiopulmonary
bypass for adult and paediatric surgery.
These standards are considered by the Society
of Clinical Perfusion Scientists of Great
Britain and Ireland, the Association of Cardiothoracic
Anaesthetists and the Society for Cardiothoracic
Surgeons in Great Britain and Ireland to
be the minimal monitoring required during
cardiopulmonary bypass. This includes monitoring
for the onset of and weaning from cardiopulmonary
bypass, and for confirmation of anticoagulation
and ventilation of the lungs.
These standards are for use in conjunction
with the Society of Clinical Perfusion
Scientists of Great Britain and Ireland
Standards of Practice document1 and local
protocols. Sources of reference include
publications from the Society of Clinical
Perfusion Scientists of Great Britain and
Ireland1, the Association of Anaesthetists
of Great Britain and Ireland2 and the American
Society of Extra-Corporeal Technology3.
(Within this document “on site facility”
is defined as on the hospital site, “near
patient facility” is defined as within
or in close proximity to the cardiac theatre.)
All centres undertaking cardiac surgery involving
cardiopulmonary bypass should plan to institute
these recommendations of monitoring by
6 months from the date of publication.
The safe conduct of cardiopulmonary bypass
is the joint responsibility of surgeons,
anaesthetists and clinical perfusionists
and requires a high level of communication
between the team members. Whilst it is
considered best practice during the conduct
of cardiopulmonary bypass for a surgeon
and an anaesthetist to be present in the
operating room at all times during cardiopulmonary
bypass, it is recognised that there are
circumstances where this may not be essential.
However, safety of the cardiopulmonary
bypass remains the primary
responsibility of the perfusionist who
must be present
at all times. These situations should be
managed using locally agreed clinical governance
guidelines and protocols should be in place
to ensure patient safety.
(Examples
of such locally agreed guidelines, in relation
to anaesthetic practice, can be found on
the ACTA website.)
Only
an accredited clinical perfusionist registered
with the College of Clinical Perfusion Scientists
of Great Britain and Ireland can undertake
or supervise the conduct of cardiopulmonary
bypass1,4,5. A named and accredited clinical
perfusionist not distracted by other clinical
commitments, in close proximity and freely
available must supervise a trainee undertaking
a cardiopulmonary bypass1.
This document is a review of the original
guidelines—it will be reviewed regularly
and may be revised or updated before the
formal publication of a new edition. For
the latest version, please refer to the
ACTA website; www.acta.org.uk
General Recommendations
Adequate records of monitoring should be kept at all times and where a variable
is monitored it should be regularly recorded.
All units should have electronic acquisition
and storage of this data, including the ability
to produce a printout2. Records should be
retained in the patient’s notes and electronically.
All monitors and alarms used should be calibrated
and maintained regularly according to the
manufacturer’s instruction and the recommended
service schedule. All equipment must be checked
before use.
During cardiopulmonary bypass, the electrocardiogram (ECG), intravascular pressures
and core body temperature should be continuously
displayed and clearly visible to the clinical
perfusionist, surgeon and anaesthetist. (Ideally,
three separate screens)
Monitoring of clinical parameters acquired directly from the patient
The following should be monitored continuously, with local protocols dictating
the frequency of recording:
Electrocardiogram (ECG)
Systemic
arterial pressure
Central
venous pressure
Core
body temperature
Urine
output should be monitored using a freely
draining urinary catheter.
Pulse
oximetry should be continuously displayed
when there is a spontaneous pulsatile circulation.
Expired
carbon dioxide tension/concentration should
be continuously displayed when the lungs
are being ventilated.
It
is accepted that special clinical circumstances
(for example emergency surgery or failure
to insert a urinary catheter) may on some
occasions preclude complete monitoring.
Monitoring
associated with the cardiopulmonary bypass
circuit
The following should be monitored continuously: Oxygen
saturation of the blood in the venous
return line.
Oxygen
tension or saturation of the blood in
the arterial line.
Continuity
of the fresh gas flow to the oxygenator using an in-line flow meter or rotameter
2.
Oxygen
concentration in the gas circuit to the
oxygenator using an oxygen analyser with
alarms, sited after the oxygen blender
and vaporiser if used 2.
Blood
flow rate generated by the arterial pump.
Arterial
line pressure.
Cardioplegia
delivery line pressure when cardioplegia
is delivered using the heart lung machine.
Temperature
of the blood in the arterial limb of
the cardiopulmonary bypass circuit.
Temperature
of water in the heater/cooler system.
Fluid
record; all fluids, drugs and blood products
added to the extra corporeal circuit
during bypass should be recorded on the
perfusion chart. Filtrate volume should
be measured and recorded when a haemofilter/
concentrator is being used.
Continuous
"in line" monitoring screens (e.g. for
potassium, haemoglobin, pH, arterial
pO2 and pCO2, arterial and venous Oxygen
saturation,) should be available.
The following measurements should be available at a near patient facility:
(Local protocols should dictate the frequency of measurements)
Anticoagulation should be confirmed by an acceptable
method e.g. activated clotting time (ACT), which
should be measured after heparinisation
and before cardiopulmonary bypass and should
be measured at regular intervals to ensure adequate
anticoagulation.
Safety devices
Local protocols for the conduct of cardiopulmonary bypass should be formulated
by all hospitals undertaking cardiac surgery
using cardiopulmonary bypass.
The following are considered best practice:
Power
failure alarm with a battery powered back-up
unit for the cardiopulmonary bypass machine.
Battery
powered Torch sited near to the bypass machine.
Bubble
detector on the arterial line of a roller pump
cardiopulmonary bypass circuit with an alarmed
automatic pump cut out facility.
Level
sensor on a hard shell venous reservoir system
in the cardiopulmonary bypass circuit with
an alarmed automatic pump cut out facility.
A
Retrograde Flow Alarm or an occlusion device is essential when using a Centrifugal Pump.
Anaesthetic
gas-scavenging apparatus whenever volatile
agents are used in the cardiopulmonary bypass
circuit6.
Out
of range temperature alarm on the heater/cooler
unit.
