LINEBURG


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Cardiac Fibromas (3%) Poor ventricular
PS ¼ pulmonary stenosis; ASD ¼ atrial septal defect; CNS ¼ central
function
nervous system; VW ¼ Von Willibrand disease
Conduction defects
Risk of endocarditis
Ovary/ Fibroma (15%) Hypertensive such as spinal abnormalities or evidence of bleeding diathesis16
uterus responses (history of easy bruising, prolonged bleeding after tooth extrac-
(some renin-secreting) tion), should also be sought. Factor deficiencies occurred in 50%
of patients reported by Sharland,14 the commonest being a reduc-
CNS ¼ central nervous system; ICP ¼ intracranial pressure;
tion in factor XI, although there are reports of a wide range of
CV ¼ cardiovascular
deficiencies in platelets and other coagulation factors. Lee17
reported spinal abnormalities in 30% of cases with Noonan syn-
management issues. The preoperative assessment should be drome, including significant scoliosis and lordosis. Although
aimed, in particular, at cardiac function (electrocardiogram odontoid dysplasia with atlantoaxial instability frequently occurs
[EKG] and echocardiogram if symptomatic or physical signs pre- with syndromes affecting the axial skeleton, making intubation a
sent), respiratory function (arterial blood gases, lung function concern, there are no reports of cervical instability associated
with Noonan syndrome.18 There are few reports of anesthesia in
tests as necessary), airway (possibility of awake intubation dis-
patients with Noonan syndrome19,20 and only six cases in
cussed), and renal function (electrolytes and creatinine) (see
parturients.21,22,23,24,25
Table 8.2). Possible contraindications to regional anesthesia,



146
Chapter 8


Schwartz and Eisenkraft19 described GA for cholecystectomy in enabled a reduction in any detrimental sympathetic stimulation
a seven-year-old child with Noonan syndrome and idiopathic and minimized variations in heart rate, contractility, and filling
hypertrophic subaortic stenosis. Although the patient had a pressures. Due to failed induction of labor, she underwent a C/S
potentially difficult airway, regional anesthesia was excluded under GA following an awake, oral fiberoptic intubation.
Magboul23 described a patient without cardiac disease requiring
due to fears of worsening cardiovascular function from vasodila-
tion, combativeness due to mental retardation, and potential an emergency C/S under subarachnoid block (SAB). Although a
technical problems inducing regional anesthesia. The patient reduced dose of subarachnoid lidocaine was used, a satisfactory
therefore was anesthetized using a halothane inhalation induc- block was obtained for the procedure. The author suggested that
tion and paralyzed only after the ability to manually ventilate the in these cases, the bony vertebral spinal canal may be narrowed
patient™s lungs was confirmed. Intubation was achieved with the with a normal caliber cord. This narrowing might reduce the size
aid of an introducer and the operation proceeded uneventfully. of the epidural and subarachnoid spaces, increasing spinal spread.
Campbell and Bousfield20 reported a five-year-old patient with In addition, the patient was short and had significant kyphosco-
increasing spasticity in both legs requiring GA for computed liosis and lumbar lordosis, which would have contributed to the
tomography (CT) scan and myelography. One of the major anes- unpredictable SAB. However, it may be argued that, as the patient
thetic concerns was hypertrophic cardiomyopathy with dynamic was known to be difficult to intubate (severe fused and webbed
left ventricular (LV) outflow obstruction (due to septal hypertro- neck, micrognathia, and Mallampati grade IV view), a reduced
phy). As intubation was not anticipated to be problematic, spinal dose of local anesthetic would have been problematic if
anesthesia was induced with thiopental, alfentanil, and atracur- the SAB were insufficient for C/S. A combined spinal“epidural
ium. The trachea was intubated easily and anesthesia was main- (CSE) or carefully titrated continuous subarachnoid anesthetic
tained with nitrous oxide, oxygen, and isoflurane. As the would be better alternatives.
procedure was short, noninvasive monitoring was used, and Two cases involved parturients with Noonan syndrome and
associated cardiac disease.24 Although both cases had character-
hemodynamic stability was maintained. Four weeks later, the
patient required a similar GA for a lumbar laminectomy and istic Noonan facies, vertebral abnormalities were not reported in
division of filum. During this procedure, invasive arterial and either case. The first case involved a 22-year-old with known
central venous monitoring were used and recovery was unevent- pulmonary and aortic stenosis. Pregnancy was complicated by
ful. Regional anesthesia for young children is rarely an option and premature rupture of the membranes (PROM), preterm labor,
˜˜awake™™ airway control or establishing invasive monitoring may and APH. A C/S was performed at 32 weeks™ gestation due to
be difficult without sedation. Clearly, in this case, achieving transverse lie, prolonged ruptured membranes, and fetal heart
hemodynamic stability was a key objective. Ketamine may not rate (FHR) decelerations. Epidural anesthesia using 2% lidocaine
be an ideal induction agent since it can increase myocardial and sufentanil was carefully titrated with the aid of direct arterial
contractility, accentuating LV outflow obstruction, which reduces monitoring. Surgery was uneventful, although the neonate was
stroke volume. discovered later to have isolated congenital cardiac disease. The
Of the six parturients with Noonan syndrome, four required second case was a patient with a known coarctation of the aorta
cesarean section (C/S). The case described by Dadabhoy and (gradient 55 mmHg). Hypertension was controlled with atenolol
Winnie21 was a parturient who underwent elective C/S for cepha- and labor induced at 38 weeks™ gestation. Pregnancy progressed
lopelvic disproportion. Although the patient had the characteris- normally and labor analgesia was provided using a CSE techni-
tic appearance of Noonan syndrome, she did not exhibit marked que, followed by a continuous low-dose epidural infusion of
respiratory dysfunction and had no evidence of cardiac abnorm- bupivacaine and fentanyl. To prevent the hemodynamic stresses
alities or mental retardation. The patient was thought to have a of prolonged pushing, a vacuum extraction was performed, and
difficult airway and, therefore, regional anesthesia was chosen. As mother and baby made uneventful recoveries. Adequate prenatal
the epidural space was difficult to locate, a spinal anesthetic was assessment, a multidisciplinary approach, appropriate cardiac
performed, producing a high (T1) block with associated hypoten- monitoring, and antibiotic endocarditis prophylaxis are import-
sion readily controlled with intravenous (i.v.) crystalloids and ant in these women.
ephedrine. Another woman with Noonan syndrome required a dilation
Two others parturients required emergency C/S.22,23 The first and curettage for postpartum bleeding after a normal vaginal
delivery.25 The main anesthetic concerns were a potentially diffi-
was a 25-year-old with severe residual cardiac disease despite
previous corrective cardiac surgery as a child.22 During her admis- cult intubation, pulmonary valve dysplasia, mental retardation,
sion she was noted to have mitral stenosis, a hypoplastic pulmon- factor XI deficiency, and thrombocytopenia. Labor analgesia was
ary valve, impaired LV function, and a dilated left atrium. provided by i.v. patient-controlled analgesia (PCA) (fentanyl 25 mg
Pregnancy was complicated by an episode of fast atrial fibrillation, bolus, five-minute lockout). Although LEA is considered the
successfully treated with digoxin, beta-blockade and thrombopro- analgesic method of choice, it was thought to pose too great a
phylaxis. She developed pulmonary edema and antepartum risk of spinal hematoma in the face of a bleeding diathesis. This
hemorrhage (APH). Unfortunately, at 30 weeks™ gestation, she risk was carefully balanced against the risk for a potentially diffi-
had an intrauterine death so labor was induced to expedite deliv- cult intubation, should emergency C/S have been required.
ery. As there was no evidence of coagulopathy, lumbar epidural Following delivery, she continued to bleed vaginally (1200 ml
analgesia (LEA) was administered using 0.1% bupivacaine. This in four hours) despite oxytocin. In order to examine her and



147
2 Musculoskeletal disorders


determine the source of bleeding, GA was induced following
Table 8.3 Clinical features of neurofibromatosis 1
awake direct laryngoscopy using cautious sedation. In addition,
she was given 15 mg of 1-deamino-8-D arginine vasopressin Organ Disease process Anesthetic implications
(DDAVP), which is a nonspecific adjunct that improves coagula-
CNS Neurofibromas Intellectual impairment
tion by increasing von Willebrand factor and factor VIII. It also
(5“40% usually mild)
increases the adhesion and spread of platelets at the injury site.
Meningiomas, gliomas Raised ICP,
The woman made an uneventful recovery.
(5“10%) hydrocephalus,
seizures
Cranial nerve fibromas Altered gag/swallowing
Neurocutaneous disorders
reflexes
Neurofibromatosis Spinal nerve fibromas Spinal-cord
compression
Neurofibromatosis is an inherited disorder affecting neurocuta-
Difficulties with regional
neous tissue, (also see Chapter 11). Two distinct forms of the disease
techniques
exist: neurofibromatosis type 1 (NF1 or von Recklinghausen disease)
Skin Caf´ -au-lait spots (99%)
e
and neurofibromatosis type 2 (NF2). Although both diseases have
Cutaneous neurofibromas Depending on site:
some common characteristics, they differ genetically and clinically.
Subcutaneous Difficult IV access
Neurofibromatosis type 1 occurs more frequently, accounting for
neurofibromas
up to 85% of patients with the disease. In fact, NF1 is the common-
Nodular neurofibromas Difficult regional
est autosomal dominant disorder affecting approximately 1:3000
techniques
births.26 The NF1 gene, located on chromosome 17q11.2,27 has a
Plexiform neuromas
high spontaneous mutation rate, with 50% of cases being spora-
Lungs Mediastinal/intercostal Impaired respiratory
dic.28,29 Although penetrance is complete, the gene has a varied
neurofibromas function/SVC
expression (i.e. the severity of the disorder will vary among indivi-
obstruction
duals). Neurofibromatosis type 1 is a progressive disease such that
Nonspecific fibrosis Right ventricular failure
excessive proliferation of neural crest elements (Schwann cells,
Kidney Renal carcinoma Renal dysfunction
melanocytes, and fibroblasts) occurs in virtually every organ system
Neurofibromas Ureteric/urethral
(see Table 8.3). In order to make a diagnosis of NF1, at least two of
obstruction
the following criteria must be present:30
CVS Congenital heart disease Depends on lesion:
 six or more caf´ -au-lait spots exceeding 5 mm in diameter in
e
(especially pulmonary Risk of endocarditis
prepubertal and 15 mm in postpubertal individuals
stenosis)
 two or more neurofibromas of any type or one plexiform
Hypertension (5%) Consider
neurofibroma
pheochromocytoma
 freckling in the axillary or inguinal regions
or renal artery stenosis
 optic glioma
Pharynx Neurofibromas Airway obstruction
 two or more Lisch nodules (benign melanotic iris hamartomas)
Larynx Dysphagia (increased
 a distinctive bony lesion such as dysplasia of the sphenoid
risk of aspiration)
bone or thinning/dysplasia of the long bone cortex with or
Difficult intubation
without pseudoarthritis
Bone Neurofibromas Difficult regional
 a first degree relative with NF1 (with the above criteria).
technique
Caf´ -au-lait spots are flat hyperpigmented macules, which
e
Fractures
increase in number and size during childhood. Neurofibromas
Kyphoscoliosis (2%, mostly Difficult intubation
are benign tumors consisting of a mixture of Schwann cells,
cervicothoracic)
fibroblasts, and mast cells. There are four distinct types of neu-
Adrenal Pheochromocytoma Hypertensive response
rofibroma: cutaneous, subcutaneous, nodular, and plexiform.
(0.1“5.7%)
Cutaneous (soft, fleshy) and subcutaneous (firm, tender) neuro-
GIT GIT tumors Pain, hemorrhage,
fibromas arise from the peripheral nerve sheath and have no
perforation
malignant tendencies. Nodular lesions also arise in peripheral
Carcinoid tumors Carcinoid syndrome
nerves and although they can cause compression effects due to
increasing size, they do not infiltrate the surrounding tissue. In CNS ¼ central nervous system; ICP ¼ intracranial pressure;
contrast, a plexiform neurofibroma usually involves multiple and IV ¼ intravenous; SVC ¼ superior vena cava; CVS ¼ cardiovascular
longer segments of nerves, and resection is difficult due to system; GIT ¼ gastrointestinal tract.
invasion. Plexiform lesions may undergo malignant change to
neurofibrosarcoma in 2“16% of NF1 patients.31 In addition
to neurofibromas, patients with NF1 are at increased risk of
developing benign and malignant tumors.32 Mutations of the



148
Chapter 8


Anesthetic management
NF1 gene result in loss of a functional protein (neurofibromin),
which normally has a tumor suppressor role. Malignancies asso- Both GA and regional (spinal, epidural) anesthesia have been
used successfully in patients with NF.40,41,42 A thorough assess-
ciated with NF1 include optic glioma, astrocytoma, brainstem
glioma, juvenile chronic myeloid leukemia, neurofibrosarcoma, ment of the patient is necessary to exclude the features outlined
rhabdomyosarcoma, medullary thyroid carcinoma, intestinal in Table 8.3. If regional anesthesia is contemplated, key areas of
tumors, and pheochromocytoma.33 Other associated conditions concern include the presence of raised intracranial pressure
include short stature, kyphoscoliosis, learning disabilities, hyper- (ICP), spinal tumors, and kyphoscoliosis. Dural puncture, in the
tension, hydrocephalus, seizures, and various congenital presence of raised ICP, or direct trauma to a spinal neurofibroma
abnormalities (pulmonary stenosis, spina bifida, rib, and verteb- from an epidural or spinal needle may have disastrous conse-
ral anomalies). quences. Although lumbar neurofibromas are usually unilateral,
Neurofibromatosis type 2 is genetically and clinically distinct they can be large, asymptomatic, and extend towards the midline
from NF1, with the responsible gene located on chromosome making them vulnerable to direct needle trauma. Despite the
22q12.1. It is considerably rarer than NF1 with an approximate majority of asymptomatic patients having no spinal involvement,
incidence of 1:50 000 births. Manifestations include bilateral acous- it is prudent to avoid neuraxial anesthesia unless recent radiolo-
tic neuromas in 95% of cases, and other CNS tumors such as gical scans exclude a spinal lesion. Some recommend magnetic
meningiomas and gliomas.34 In common with NF1, it is inherited resonance imaging (MRI) or CT of the brain and spinal cord late
in an autosomal dominant manner, with 50% of cases resulting in pregnancy, as tumors may grow significantly during ges-
tation.43 One case of LEA in a parturient with NF was complicated
from spontaneous mutation.
The following criteria are required to make a diagnosis of NF2:30 by dural puncture and subsequent epidural hematoma.
 bilateral vestibular schwannomas (bilateral ˜˜acoustic neuro- Fortunately, the patient made a full recovery with conservative
mas™™), or treatment, but the case highlighted communication problems
 history of NF2 in first-degree relative plus any two of the and the need for a thorough assessment prior to anesthetic
management.43
following:
 meningioma As pheochromocytoma complicates 0.1“5.7% of patients with
NF1,44 it is vital to exclude this condition, particularly in those
 glioma
 schwannoma patients with sustained or paradoxical hypertension resistant to
 juvenile posterior subcapsular lenticular opacities treatment. If GA is considered, the main areas of concern include
 juvenile cortical cataract. the possibility of a difficult intubation and/or airway obstruc-
tion.45 Neurofibromas may involve the tongue, larynx, or trachea
Cutaneous lesions such as caf´ -au-lait spots and neurofibro-
e
mas are seen in up to 70% of patients with NF2, although plexi- and cause airway obstruction and difficult intubation. Plexiform
form neuromas are not seen. neurofibromas occur commonly in the cervical region and may
distort the airway. Symptoms of dyspnea, stridor, or change in
Neurofibromatosis in pregnancy voice should alert one to potential airway problems. Even if recog-
Although NF has no detrimental effect on fertility in women, nized early, elective awake fiberoptic tracheal intubation may not
pregnancy itself poses an increased risk to the parturient and her be successful due to the distorted anatomy. Neuromuscular
blocking drugs can be used in normal doses in patients with NF.46
fetus. Neurofibromas are known to increase in number and size
during pregnancy and regress in the postpartum period. It is
speculated that there may be a link between the growth of neuro-
Tuberous sclerosis (Bourneville-Pringle disease)
fibromas and levels of circulating hormones because progester-
one, estrogen, and growth hormone receptors are all found in Tuberous sclerosis (TS) has been described as a triad of seizures,
neurofibromatous tissue. mental retardation, and a central facial skin eruption (mislabeled
˜˜adenoma sebaceum™™), but it is clearly a multiorgan disease.47
Other detrimental effects to the parturient include: presence of
pelvic/abdominal neurofibromatas making C/S necessary (dysto- Pathology consists of a hamartomatous proliferation in the brain,
cia, obstructed labor or respiratory embarrassment),35 predis- spinal cord, skin, kidney, eyes, heart, lungs, and bones (see
position to hypertension,36 possible death from undiagnosed Table 8.4). This slowly progressive disease is inherited in an
pheochromocytoma, renal artery stenosis and HELLP (hemolysis, autosomal dominant manner with variable expression. The inci-
elevated liver enzymes, and low platelets) syndrome,37 renal artery dence is quoted as 1 in 5000“10 000 births; however, as there is a
rupture or other vascular complications, and, rarely, malignant wide expression in the severity of the disease, the true incidence
degeneration of neurofibromata.38 Posma38 described a case of a and prevalence is unknown. Causative mutations in two separate
malignant mediastinal schwannoma in a parturient, who required genes have been found in patients with TS, one located on chro-
mosome 9q34 and the other on 16p13.3.48 Only one third of cases
a therapeutic abortion in order to undergo radiotherapy for the
treatment of her tumor. During her second pregnancy, despite are familial. In order to make a diagnosis of TS at least two major
features or one major and two minor features must be present:47
being in remission for over three years, she developed a recurrence
and died shortly after giving birth. Detrimental effects to the fetus Major features:
 facial angiofibromas, formerly called ˜˜adenoma sebaceum™™
include: increased risk of spontaneous abortion, stillbirth, intrau-
terine growth restriction (IUGR), and preterm labor.35,39  Shagreen patch (connective tissue nevus mostly over trunk)


149
2 Musculoskeletal disorders


 retinal achromic patch
Table 8.4 Clinical features of tuberous sclerosis
 cerebral white matter radial migration lines.
The morbidity and mortality of cardiac rhabdomyomas is
Anesthetic
determined by flow abnormalities if they are of a sufficient
Organ Disease process implications
size to impair cardiac outflow. Coarctation of the aorta, con-
Brain Cortical hamartomas (gyri & Epilepsy (80%)
striction of the major arteries (e.g. renal stenosis), and aortic
subependymal)
aneurysm are all associated with TS. The main neurological
Astrocytomas (15%) Mental retardation
lesions are due to hamartomas, with giant cell tumors (astro-
(mild to severe 70%)
cytomas) occurring in 10“15% of patients with TS. These
Calcification Focal neurological
patients typically present with signs and symptoms of hydroce-
signs
phalus or focal neurologic signs. The majority of patients with
Hydrocephalus
TS have neurologic abnormalities, including cognitive deficits,
Skin Hypopigmented macules Nil
learning disabilities, and seizures. The extent of cerebral dys-
(ash-leaf spots) (90%)
function is directly related to the number of cortical tubers. The
Red/yellow papules (central
pulmonary manifestations of the disease include lymphangio-
face-˜˜adenoma sebaceum™™
leiomyomatosis (LAM), which is a condition in which there is
(90%))
hamartomatous proliferation of the smooth muscle of the
Shagreen papules-
respiratory bronchioles, pulmonary arterioles, and pulmonary
lumbosacral (40%)
lymphatic vessels.49 The onset of LAM occurs mostly between
Caf´ -au-lait spots (12%)
e
30“40 years, coinciding with the age of parturients. Although
Periungal fibroma (40%)
progression of LAM is variable, it has a poor prognosis, resulting
Kidney Renal hamartoma Deterioration of renal
in significant limitation of lung function due to destruction of
(angiomyolipomas) (65%) function
lung tissue from hamartomatous cavitation. The commonest
Cysts Pain/hemorrhage into
presentations are dyspnea and pneumothorax (from rupture of
cysts
peripherally located cysts into the pleural space). Tuberous
Eyes Retinal hamartomas (50%) Nil
sclerosis is associated with a variety of benign tumors, and an
Heart Rhabdomyomas (50%) Conduction defects,
increased risk of malignancy, the commonest being cerebral
dysrhythmias,
tumors and rhabdomyosarcomas.
congestive heart
failure,
Effect of pregnancy on the disease
risk of endocarditis
There are several reported cases of tuberous sclerosis in preg-
Lungs Smooth muscle hamartomas Progressive
nancy,50,51,52,53 and many are associated with serious maternal
(lymphangiomyomas) (1%) deterioration of lung
and fetal complications. In a study by King et al. 43% of women
function
with TS had perinatal problems (see Table 8.5).53 There was also
Cysts
an increased risk for fetal cardiac rhabdomyomas, which cause
fetal demise if > 3 cm and are associated with fetal cardiac dys-
rhythmias. Women with TS can also present with seizures, which
 three or more hypomelanotic macules (ash-leaf spots “
could confound a diagnosis of eclampsia, since there are reports
elliptical in shape)
of preeclampsia in TS patients.
 nontraumatic ungula or periungual fibroma
Despite these concerns, many women with TS have uncompli-
 lymphangioleiomyomatosis (also known as
cated pregnancies.54 However, having prior knowledge of the full
lymphangiomyomatosis)
extent of the disease (organ involvement) will allow one to be
 renal angiomyolipoma
prepared for a potentially complicated pregnancy. Renal involve-
 cardiac rhabdomyoma
ment can be associated with a poor prognosis and patients with
 multiple retinal nodular hamartomas
renal angiomyolipomas are at risk of profound hemorrhage.55
 cortical tumor
 subependymal nodules
 Anesthetic management
subependymal giant cell astrocytoma.
There are a limited number of case reports concerning the man-
Minor features:
agement of anesthesia in adult patients with TS.56,57,58 Although
 confetti skin lesions (multiple 1“2 mm hypomelanotic macules)
 gingival fibromas several parturients described in case reports required labor
 multiple randomly distributed pits in dental enamel analgesia or anesthesia for instrumental delivery, the reports failed
 hamartomatous rectal polyps to detail specific anesthetic management. Of importance to the
 multiple renal cysts anesthesiologist is a history of seizures, mental retardation, focal
 nonrenal hamartomas neurological signs, hydrocephalus, renal dysfunction, ventricular
 bone cysts dysfunction, dysrhythmias, and poor pulmonary function.



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Chapter 8



Table 8.5 Perinatal problems with tuberous sclerosis Table 8.6 Clinical features of von Hippel-Lindau disease
Maternal Organ Disease process Anesthetic implications
 Skin lesions
CNS Hemangioblastomas Raised ICP
 Mental retardation
involving:
 Seizures
cerebrum (2%) Risk of CNS
 Placental abruption
hemorrhage
 Preeclampsia

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