Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3612_Библиотеки_им_академика_М_И_Перельмана
.pdf
240
Key Questions in CONGENITAL CARDIAC SURGERY
If transverse arch hypoplasia accompanies discrete coarctation, it
•
may also be tackled using stent angioplasty with the recognised
problems of crossing the major head and neck vessels. In such
circumstances, open cell design stents are ideally suited.
Recommended reading
1. Jayaram N, Beekman RH, Benson L, Holzer R, Jenkins K, Kennedy KF, Martin GR,
Moore JW, Ringel R, Rome J, Spertus JA, Vincent R, Bergersen L. Adjusting for risk
associated with pediatric and congenital cardiac catheterization: a report from the
NCDR®IMPACT™ Registry.
2. Zahn EM, Nevin P, Simmons C, Garg R. A novel technique for transcatheter patent
ductus arteriosus closure in extremely preterm infants using commercially available
technology.
3. Prabhu S, Anderson B, Ward C, Karl T, Alphonso N. A simplified technique for
interventional extracardiac Fontan.
4. Cheatham JP, Hellenbrand WE, Zahn EM, Jones TK, Berman DP, Vincent JA,
McElhinney DB. Clinical and hemodynamic outcomes up to 7 years after transcatheter
pulmonary valve replacement in the US melody valve investigational device exemption
trial.
5. Feltes TF, Bacha E, Beekman RH 3rd, Cheatham JP, Feinstein JA, Gomes AS, Hijazi
ZM, Ing FF, de Moor M, Morrow WR, Mullins CE, Taubert KA, Zahn EM; American
Heart Association Congenital Cardiac Defects Committee of the Council on
Cardiovascular Disease in the Young; Council on Clinical Cardiology; Council on
Cardiovascular Radiology and Intervention; American Heart Association. Indications
for cardiac catheterization and intervention in pediatric cardiac disease: a scientific
statement from the American Heart Association.
6. Meadows J, Minahan M, McElhinney DB, McEnaney K, Ringel R; COAST
Investigators. Intermediate Outcomes in the Prospective, Multicenter Coarctation of
the Aorta Stent Trial (COAST).
7. Kang SL, Jivanji S, Mehta C, Tometzki AJ, Derrick G, Yates R, Khambadkone S, de
Giovanni J, Stumper O, Dhillon R, Bhole V, Slavik Z, Rigby M, Noonan P, Smith B,
Knight B, Richens T, Wilson N, Walsh K, James A, Thomson J, Bentham J, Hayes N,
Nazir S, Adwani S, Shauq A, Ramaraj R, Duke C, Taliotis D, Kudumula V, Yong SF,
Morgan G, Rosenthal E, Krasemann T, Qureshi S, Crossland D, Hermuzi T, Martin RP.
Outcome after transcatheter occlusion of patent ductus arteriosus in infants less than
6kg: a national study from United Kingdom and Ireland.
2017; 90(7): 1135-44.
8. Hascoët S, Baruteau A, Jalal Z, Mauri L, Acar P, Elbaz M, Boudjemline Y, Fraisse A.
Stents in paediatric and adult congenital interventional cardiac catheterization.
`~кЗбзо~лЕ=aбл
`~нЬЙнЙк=`~кЗбзо~лЕ=fенЙко
`бкЕмд~нбзе
2015; 131(22): 1960-70.
2014; 107(8-9): 462-75.
`бкЕмд~нбзе
`бкЕмд~нбзе
2015; 132(20): 1863-70.
2015; 85(2): 240-8.
tзкдЗ=g=mЙЗб~нк=`зеЦЙебн=eЙ~кн=pмкЦ
`бкЕмд~нбзе
2015; 131(19): 1656-64.
2011; 123(22): 2607-52.
`~нЬЙнЙк=`~кЗбзо~лЕ=fенЙко
2017; 8(1): 92-8.
^êÅÜ
Chapter 7
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Anaesthesia and congenital heart disease
Michael Puntis, Sian Jaggar
1 Describe the involvement of anaesthetists in the care
of patients with congenital heart disease
During pre-operative planning and peri-operative care of patients
•
undergoing cardiac surgical interventions.
Providing general anaesthesia or sedation for patients undergoing
•
percutaneous interventions in the cardiac catheter laboratory.
Providing intensive care support for both adult and paediatric
•
patients.
Providing anaesthesia for non-cardiac interventions, including:
•
a) specialist interventions — such as pain management or
vascular access;
b) general surgical interventions unrelated to the cardiac disease;
c) obstetric interventions — where the greatly increased
physiological demands of pregnancy may precipitate cardiac
problems, requiring close liaison between medical, obstetric
and anaesthetic staff.
241
2 Describe the factors that determine the use of
anaesthesia or sedation
Patient factors:
•
a) age;
b) comorbidity;
c) cognitive and psychological considerations.
Procedural factors:
•
a) position required;
b) duration;
c) degree of invasiveness.
242
Key Questions in CONGENITAL CARDIAC SURGERY
3 What are the differences between neonates and
older children from an anaesthetic point of view?
Airway — the neonatal airway is more challenging to manage
•
because the:
a) prominent occiput pushes the neck into flexion when supine;
b) tongue is relatively large;
c) epiglottis is floppy and U-shaped, and the larynx is relatively
cephalad.
Breathing — in the neonate, hypoxia occurs much more rapidly;
•
this is affected by:
a) neonatal respiratory centres — which although mature are
more easily suppressed by drugs or hypothermia;
b) intercostal and diaphragmatic muscles — which contain
fewer Type I (slowly contracting, highly oxidative) muscle
fibres and are easily fatigued;
c) reduced mechanical advantage — as the ribs are relatively
horizontal, requiring a greater contribution from the
diaphragm;
d) reduced functional residual capacity (FRC) — which usually
provides a store of oxygen. This results from low lung
compliance, despite a relatively compliant chest wall;
e) higher airway resistance with increased work of breathing —
which consumes more of the inspired oxygen;
f) foetal-type acetylcholine receptors, expressed in neonates —
which are more sensitive to depolarising muscle relaxants,
hence, normal respiratory function may take longer to
recover.
Circulation — which requires different management because:
•
a) neonatal cardiac output is particularly rate-dependent, as
stroke volume cannot readily be increased;
b) neonatal myocardium is relatively stiff and less able to
increase contractility or respond to preload;
c) neonates have a proportionally much greater cardiac output,
due to an increased heart rate (400mL/kg/min at birth,
150mL/kg/min at 8 weeks and 70mL/kg/min at puberty).
7 Anaesthesia and congenital heart disease
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Pharmacology — where many important pharmacokinetic factors are
•
less well developed, including:
a) absorption — neonatal drug absorption is altered by increased
gastric pH, slower gastric emptying and increased intestinal
transit time;
b) distribution — the blood-brain barrier is less well developed
and sedative drugs may cross more easily;
c) metabolism — neonates can metabolise most drugs but more
slowly than older children;
d) excretion — renal excretion is impaired, especially in the
preterm neonate. Some drugs, such as aminoglycosides, need
to be administered less frequently.
Temperature control — neonates and infants have an increased
•
surface area to volume ratio, favouring heat loss. Steps to maintain
normothermia include ensuring adequate ambient temperature and
the use of forced air warmers. Generating heat to maintain body
temperature causes a dramatic increase in metabolic demands on
the neonate.
Communication — as cognitive function develops, a child’s ability to
•
understand, communicate and reason improves. The developmental
stage impacts upon interaction with both the child and parents.
243
4 What are the principles of pre-operative assessment
and preparation of paediatric cardiac surgical
patients for anaesthetists?
Information should be gathered first, including:
•
a) history — review of the case notes and discussion with the
patient/parents for information about the cardiac diagnosis,
other related comorbidity and history of any previous
anaesthesia (both for the child and family members);
b) examination — especially considering ease of airway
management and potential vascular access sites;
c) investigations — especially those relevant to the
cardiovascular and respiratory status.
All correctable medical conditions should be optimised prior to
•
surgery and any issues that cannot be changed must be accepted.
The risk level should be stratified to plan for peri-operative care.
•
Critical care is mandatory for most cardiac surgical procedures and
244
Key Questions in CONGENITAL CARDIAC SURGERY
more common for many other procedures than for patients without
congenital heart disease.
Rapport must be established with both the patient and their family.
•
Anxious patients suffer more adverse events, such as laryngospasm,
during anaesthesia and premedication may help.
Induction using intravenous or inhalational agents should be
•
discussed with the child and parents, to aid compliance. Patients and
parents should be aware of and accept the risks associated with the
planned techniques, including invasive monitoring.
Details of starvation times should be documented, especially as
•
patients with congenital heart disease are at particular risk from
dehydration, potentially caused by excessive starvation times. The
usual rules are:
a) clear (non-fizzy) fluids — 1 hour before anaesthesia;
b) breast milk — 4 hours before anaesthesia;
c) other milk or food — 6 hours before anaesthesia.
Options for analgesia and their relevant risks should also be
•
discussed.
5 Which investigations are helpful to the anaesthetist in
the pre-operative assessment?
Many routine investigations are performed to screen for unidentified
•
problems and to provide a baseline assessment of the patient’s
physiology and metabolic status. Although most pre-operative
investigations are performed primarily for surgical reasons, they
provide useful anaesthetic information.
Blood tests, including:
•
a) full blood count (FBC) — which establishes the presence of
polycythaemia or anaemia. Cyanotic patients require higher
haemoglobin levels for adequate oxygen delivery;
b) haemoglobinopathy screen (including HbSS) — which should
be performed in the relevant patient groups, especially if
cooling is planned, which may cause a sickle crisis. In cases
where hypothermia presents significant risks, the surgeons,
anaesthetists and perfusionists may agree to maintain a normal
body temperature on bypass;
c) platelet count and coagulation studies — especially as
cyanotic patients are prone to bleeding, even when laboratory
findings are normal. Ordering products early helps to ensure
rapid and effective management;
7 Anaesthesia and congenital heart disease
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
d) urea & electrolytes — as abnormalities increase the risk of
myocardial irritability or indicate underlying renal dysfunction.
Arrhythmias are particularly important when cardiac function is
borderline;
e) pregnancy test — which is indicated for all female patients
post-menarche. Careful communication is vital for these
patients.
Electrocardiogram (ECG) — to identify signs of any conduction
•
abnormalities or arrhythmias, which may require peri-operative
pacing interventions (temporary or permanent).
Chest radiograph (CXR) — which provides information regarding
•
the:
a) lower airway — including the size of the lungs;
b) other anatomical abnormalities — such as sequestrated lung
or diaphragm anomalies;
c) respiratory disease — such as acute airways or parenchymal
infections requiring treatment;
d) non-infectious lung disease — which may or may not require
therapy but might affect peri-operative risk or affect prognosis.
245
Specific investigations, such as cardiac catheterisation and
•
echocardiography, which define abnormal anatomy and physiology
can also identify high-risk lesions that may influence the conduct or
risk of anaesthesia.
6 What psychological, social and legal issues may arise
when assessing paediatric patients for anaesthesia?
A patient’s understanding varies quite considerably, depending on
•
age, educational level, cognitive ability and complexity of the lesion.
Some patients have great insight into their condition, while others will
have little or none.
Anxieties or phobias may develop following multiple interventions and
•
admissions. These should be actively managed prior to further
intervention and the anaesthetist should be involved at an early stage.
Younger patients and those with learning difficulties may need
•
information provided in differing formats, including for postoperative
care and appropriate pain-scoring tools.
Language barriers can present insurmountable obstacles to
•
communication, and in these cases, interpreters are required during
anaesthetic assessment, as they are during surgical consenting.
246
Key Questions in CONGENITAL CARDIAC SURGERY
7 Which comorbidities or patient factors should be
discussed with the anaesthetic team early?
Some situations require additional planning and surgery may be
•
delayed if the anaesthetist is unaware of issues until the day of
surgery.
Abnormal airways — patients with congenital heart disease may have
•
associated abnormal airway anatomy, making conventional
laryngoscopy difficult. Further airway assessment or alternative
techniques may need to be planned. In adults, a number of tests are
able to predict difficult intubation, although none are particularly
specific or sensitive. Similar tests are not validated in children.
Conditions known to be associated with difficult intubation include:
a) trisomy 21;
b) Pierre-Robin syndrome;
c) DiGeorge syndrome.
Significant comorbidity, such as pulmonary disease, may necessitate
•
prolonged postoperative critical care and therefore require advanced
planning. Patients with congenital heart disease with varying degrees
of learning difficulties, or other neuropsychological issues, may be
poorly compliant with postoperative care, including respiratory care,
mobility and medications.
Psychological problems, such as anxiety or needle phobia, may
•
require addressing pre-operatively. Older children and patients in
transitional age may present significant problems with compliance,
especially those with previous surgical experiences.
8 Describe how congenital heart disease is broadly
classified for planning of anaesthetic management
A normal circulation is characterised by equal pulmonary and
•
systemic flow in functionally serial circulations. This may be disrupted
in patients with congenital heart disease.
Pathology can be considered in terms of how changes in pulmonary
•
and systemic vascular resistances influence flow:
a) increased pulmonary blood flow — with systemic to pulmonary
shunting of blood (Figure 1). This type of shunt lesion includes:
i) atrial septal defects (ASD);
ii) ventricular septal defects (VSD);
iii) atrioventricular septal defects (AVSD);
iv) patent ductus arteriosus (PDA);
7 Anaesthesia and congenital heart disease
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Figure 1. Systemic to pulmonary (left to right) shunt through an atrial
septal defect causes increased pulmonary blood flow, as well as right
atrial and right ventricular volume overload. RA = right atrium; RV = right
ventricle; LA = left atrium; LV = left ventricle.
These are usually initially acyanotic conditions, mostly
characterised by volume overload and congestive heart failure
but pulmonary hypertension (PHT) may appear and cause
reversal of the shunt and cyanosis;
b) decreased pulmonary blood flow — with pulmonary to
systemic (often right to left) shunting of blood (Figure 2). This
occurs when the resistance to flow is higher through the
pulmonary than the systemic circulation and includes:
i) tetralogy of Fallot;
ii) pulmonary atresia with or without VSD;
iii) double-outlet right ventricle (DORV) of tetralogy type;
iv) DORV of transposition of the great arteries (TGA) type.
These are typically cyanotic lesions, due to the mixing of blood
from the systemic venous return into the systemic circulation.
In some cases, the mixing is obligated and complete (such as
in pulmonary atresia), whereas in others, the degree of mixing
depends on the degree of obstruction of the outflow tract and
can vary in different physiological conditions (such as in
tetralogy of Fallot);
247
Key Questions in CONGENITAL CARDIAC SURGERY
248
Figure 2. Higher resistance to pulmonary blood flow (mechanical or
physiological) results in pulmonary to systemic (right to left) shunting
(through an atrial septal defect) and reduced arterial oxygen saturations.
RA = right atrium; RV = right ventricle; LA = left atrium; LV = left ventricle.
c) decreased systemic blood flow — which is often associated
with systemic hypoperfusion (Figure 3). This condition is
associated with a few anomalies, such as:
i) coarctation of the aorta;
ii) hypoplastic left heart syndrome (HLHS);
iii) congenital severe aortic stenosis;
iv) total anomalous pulmonary venous connections (TAPVC)
with obstruction to left atrial inflow;
v) TGA with a small PDA or restrictive ASD;
d) balanced parallel circulation — where pulmonary and systemic
blood flow are well balanced but not necessarily equal (Figure
4). This type of physiology is seen in:
i) functionally single-ventricle circulations — HLHS, absent
interventricular septum, unbalanced AVSD, hypoplastic
right heart syndrome (HRHS);
ii) truncus arteriosus with a large VSD.
In these cases, the balancing of the two circulations is due to
the relative resistance of the two vascular beds. In some
cases, there may be a mechanical obstruction to the pulmonary
circulation preventing the circulation to overflow to the lungs.
7 Anaesthesia and congenital heart disease
Данная книга находится в списке для перевода на русский язык сайта https://meduniver.com/
Figure 3. Decreased systemic blood flow distal to an obstruction (left
ventricular outflow tract obstruction). RA = right atrium; RV = right
ventricle; LA = left atrium; LV = left ventricle.
249
Figure 4. Balanced circulation with total mixing of blood in a ‘common
ventricular cavity’. The oxygen saturations of blood entering the systemic
and pulmonary circulations are the same. RA = right atrium; RV = right
ventricle; LA = left atrium; LV = left ventricle.
Соседние файлы в папке Библиотека им академика М.И. Перельмана