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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3753_Библиотеки_им_академика_М_И_Перельмана
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Anaesthesia for Endoscopic Cardiac Surgery 29
Video 12 Inflation of bronchial blocker (▶ https://doi.org/10.1007/000-a6z)
arterial cannula is measured through a transducer. Good trace and mean pressure in line with
arm pressures will indicate good position of
femoral arterial cannula (Fig. 12).
Following this the endo balloon and guide
wire will be inserted through the y connection in
the arterial cannula under TOE guidance. The
endo balloon is positioned in the ascending aorta
at the level of pulmonary artery. The cardiopulmonary bypass is initiated and descending thoracic aorta is monitored using TOE guidance.
Once bypass is established the three arterial wave
forms (Left arm, Right arm and Femoral) should
read similar mean arterial pressures (Fig. 13).
16 Cardioplegia Delivery
The ascending aorta is clamped using either the
endo balloon or chitwood clamp. In some cases,
beating heart technique is employed. In these
cases, Esmolol is used as a bolus of 0.5 mg/kg
followed by an infusion of 100mcg/kg/hr and
adjusted accordingly to maintain bradycardia.
This is stopped at the time of rewarming.
Chitwood clamp is used in a similar fashion to
aortic cross clamp.
When the endo balloon is used as a method
for cardioplegia the following steps are observed.
Communication between the surgeon, anaesthetist, perfusionist and the scrub staff is paramount at this stage to maintain safety and
achieve best results (Video 13).
1. The tip of the endo balloon is connected to
the pressure transducer that is used to monitor
the femoral pressure through a manometer
line. This will read similar mean pressures as
arm pressures.
2. The balloon is then inflated with ‘n’ mls of
saline (where n was the measured aortic
diameter in mm). During inflation of the
balloon there is a potential movement of the
balloon distally blocking right innominate
artery. This will be identified by fall in right
arm pressure followed by right cerebral saturation after a delay.
3. When the balloon is nearly inflated to the size
of ascending aorta (approximately 15–20mls
of saline), adenosine is administered at a dose
of 250 lg/kg through the distal lumen of the
30 A. Knowles and P. Saravanan
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Fig. 12 Pressure traces following insertion of femoral cannula
Fig. 13 Pressure traces following onset of cardiopulmonary bypass
Anaesthesia for Endoscopic Cardiac Surgery 31
Video 13 Endoclamp balloon inflation (▶ https://doi.org/10.1007/000-a70)
endo balloon directly into the partially
occluded aortic root causing cardiac standstill
to allow accurate landing of the balloon. This
prevents ventricular ejection and allowing the
full balloon inflation to occur without movement of the balloon.
4. When the balloon is inflated to the required
diameter, a drop in the pressure of the endo
balloon manometry line is seen indicating
occlusion of the ascending aorta and isolation
from CPB pressure in the distal aorta.
5. Cardioplegia is administered through the balloon which will maintain asystole and facilitate
surgery. The balloon tip pressure can be seen to
rise during cardioplegia administration.
6. The whole procedure is performed under
TOE guidance with monitoring of arm and
balloon tip press ures while maintaining good
communication.
17 Management During CPB
The management of patients on bypass is similar
to sternotomy. Management of anticoagulation,
gas exchange, temperature and flows follow the
same line as in patients having cardiac procedures with sternotomy. The variations in management include,
1. The patients are filtered on bypass to maintain
neutral fluid balance while using crystalloid
cardioplegia through endo balloon (Fig. 14).
2. The acid base balance is corrected using
Insulin infusions all through CPB and
Sodium bicarbonate boluses during rewarming as required.
3. Cerebral oximetry is used as a guide for
venous drainage and perfusion in addition to
standard monitoring during bypass .
18 Separation
from Cardiopulmonary Bypass
1. Endo balloon is deflated under TOE guidance
and deairing is performed through the tip of
balloon.
2. TOE is used to assess the success of the
surgical procedure.
3. Separation from CPB is optimally achieved
with the resumption of two lung ventilation
rather than single lung ventilation to allow for
optimal oxygenation, normocarbia and lower
pulmonary vascular resistance. Therefore,
surgical haemostasis must be ensured before
the view is obscured by complete inflation of
the right lung.
32 A. Knowles and P. Saravanan
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Fig. 14 Haemofilter added to cardiopulmonary bypass circuit
Anaesthesia for Endoscopic Cardiac Surgery 33
4. The use of TOE on separation from CPB is
key in assessing right ventricular performance
on resumption of volume loading, the effect
of any residual air entering the right coronary
artery and subsequently following protamine
administration. Left ventricular performance
is analysed in the standard way followed by
assessment of the surgical procedure.
19 Cerebral Oximetry
The use of cerebral oximetry in cardiac surgery
has been much debated and usually in relation to
post-operative cognitive dysfunction [7, 8].
However in endoscopic cardiac surgery it is a
vital monitor
1. To confirm the adequacy of venous drainage
with or without neck cannula,
2. A marker of perfusion with peripheral bypass
and
3. An adjunct to the two arterial lines system for
monitoring the position of an endo balloon.
The right arm pressure and right cerebral
oximetry are set to display above the respective
left side measurements for standardisation and
ease of visual identification during placement of
endo balloon.
20 Removal of Jugular Venous
Drainage Cannula
Following the administration of protamine, the
cannula is clamped proximal to the side port
which is then opened to allow drainage of blood in
the lines back to the perfusionist (Video 14). After
correcting any coagulation abnormalities, the
patient is placed in a slight Trendelenburg position to avoid air embolism and the venous cannula
withdrawn (Video 15) using a cannula removal kit
(Fig. 15). Digital pressure is applied for usually
up to 10 min. Once haemostasis is achieved,
wound closure strips and an occlusive dressing are
applied to the insertion site (Video 16).
21 Postoperative Care
These patients a re managed postoperatively in
the cardiac intensive care in our unit. The postoperative management is similar to sternotomy
patients [11] and includes early extubating,
analgesia and management of complications.
21.1 Analgesia
Analgesia postoperatively is achieved by multimodal approach. Smaller chest incisions and lack
of rib spreading techniques make it easier to
control postoperative pain. Paravertebral nerve
blocks with continuous infusion through a catheter is an option. After a bolus of 0.25% bupivacaine and placement of catheter an infusion of
0.25% bupivacaine can be used. It is usually
performed after induction of anaesthesia and prior
to surgical incision (Video https://www.nysora.
com/techniques/neuraxial-and-perineuraxial-tech
niques/thoracic-lumbar-paravertebral-block/). Int-
ercostal nerve blocks after protamine can be performed by surgeons with thoracic experience
using up to 30mls of 0.25% bupivacaine with 3–4
mls in each space from 3rd to 8th spaces combined with wound infiltration. Smaller chest
incision can make it difficult but on the other hand
larger incisions are the ones which would require
this. The regional analgesia methods are often
supplemented with regular paracetamol and
Gabapentin along with opioids as required. In
authors experience Gabapentinoids are particularly helpful for pain associated with drains.
Prompt drain removal helps in better pain management and mobilisation.
34 A. Knowles and P. Saravanan
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Video 14 Clamping and returning of blood via venous drainage cannula (▶ https://doi.org/10.1007/000-a71)
Anaesthesia for Endoscopic Cardiac Surgery 35
Video 15 Removal of venous drainage cannula (▶ https://doi.org/10.1007/000-a6m)
Fig. 15 Venous cannula removal kit
36 A. Knowles and P. Saravanan
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Video 16 Dressing of cannulation site (▶ https://doi.org/10.1007/000-a73)
Anaesthesia for Endoscopic Cardiac Surgery 37
22 Pulmonary Oedema
Unilateral pulmonary oedema (UPE) of the
unventilated right lung has been reported from
centres performing minimal access surgery
around the world with an incidence of 0.6 to 20%
[11–14]. Bilateral pulmonary oedema is reported
as well. The etiology of this problem is unclear.
These seem to have occurred more frequently
during the initial stages of setting up the program. Various theories have been propos ed.
COPD, renal dysfunction, prolonged bypass
times, transfusion, right ventricular dysfunction
and injury to pulmonary veins are some of the
causes stipulated and associated mortality can be
high. The authors had two incidences of pulmonary oedema both of which recovered by
48 h. There are multiple reports of UPE from UK
centres and five patients have needed extra corporeal membrane oxygenation (ECMO) support.
A number of measures have been proposed to
minimise the risk. These include
1. Choosing surgically straightforward cases at
the beginning of the program to minimise
bypass times
2. Neck cannula for every patient during the
start of the program to improve the drainage
and surgical access
3. One lung ventilation strategy with pressure
controlled ventilation with the driving pressures of 15cms of water or less.
4. Fluid restrictive strategy intraoperatively with
routinely filtering on bypass
5. Use of centrifugal pumps
6. Use of steroids perioperatively
Treatment includes lung protective ventilation, identifying and treating potential surgical
causes, steroids and ECMO if ventilatory support
fails.
22.1 Bleeding and Re-exploration
Bleeding is usually less common after minimal
access procedure. Use of endoballoon and
avoiding incision on aorta are some of the proposed factors. Bleeding can occur from the chest
wound due to injury to intercostal artery or from
chest wall due to preexisting adhesions. Initial
management of bleeding is similar to post sternotomy patients [15]. Postoperative chest x-ray
or ultrasound will help in diagnosing chest collection. If exploration is required, it can be performed by video assisted thoracoscopic
technique. In an emergency, the chest needs to be
reopened via sternotomy. Electric saw to facilitate immediate chest opening in cardiac ITU in
the rare event of cardiac tamponade is required
and should be part of the emergency reopening
tray (Fig. 16).
22.2 Pacing After Surgery
Epicardial pacing wires are placed under vision
to facilitate pacing if required. Occasionally the
wires may need to be placed rather than stitched
on the inferior surface of the heart due to difficult
access. Higher threshold may be needed to
achieve capture in these circumstances. This
more often is the case following redo surgeries
because of adhesions posing difficulty in placing
the wires. We use transvenous pacing catheters in
cases with anticipated difficulty (Fig. 17). Other
options include isoprenaline infusion or transvenous pacing wire insertion by cardiologist.
22.3 Haemodynamic Instability
Abnormal pacing if the wires are not stitched to
right ventricle or occlusion or impingement of
circumflex artery are some of the potential causes
for haemodynamic instability after minimal
access surgery. Pacing can be switched off if
there is an underlying rhythm. If there is no
underlying rhythm or severe bradycardia, transcutaneous pacing and isoprenaline infusion can
be used while transvenous pacing is established.
Circumflex artery occlusion or impingement
is a rare complication following mitral valve
surgery and can cause haemodynamic instability.
Usually this would have been identified intraoperatively during TOE assessment as poor
function of lateral wall of left ventricle associated
38 A. Knowles and P. Saravanan
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Fig. 16 Emergency sternotomy equipment
Fig. 17 Pacing PA catheter and attachments
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