Transcript Neonatal Autopsy

NEONATAL AUTOPSY TECHNIQUE
SPECIAL DISSECTION PROCEDURES
MAIN DEFINITIONS
AND TERMS IN NEONATOLOGY
• THE DEATH OF NEWBORN:
– it is a lethal outcome before the 28th day of life
• PERINATAL DEATH:
– death before delivery, during delivery or during first 7 days of life
• FULL-TERM NEWBORN:
– newborn delivered between 38-42 hbd
– PREMATURE NEWBORN
– newborn delivered 26-37 hbd
• POSTMATURE NEWBORN:
– newborn delivered after the 42 hbd
• VIABLE FETUS:
– fetus delivered with weight over 1000g and length over 36-38 cm
• AN INFANT WITH POSTMATURITY SYNDROME
IS CALLED ALSO DYSMATURE OR POSTTERM
• Postmature infant with characteristic skin
changes; the skin is dry, cracking, and
desquamating.
Apgar Score Rates
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Respiration, crying
Reflexes, irritability
Pulse, Heart rate
Skin color of body and extremities
Muscle tone
• A system of evaluating a newborn’s physical
condition by assigning a value (0,1,2) to each of
five criteria
MAIN CAUSES OF DEATH IN INFANCY
Cause of Death
• Natural:
– immaturity
– malformation
– disease of heart
– lungs or brain
– meconium aspiration
– Rh incompatibility
Cause of Death
• Accidental:
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cord prolapse
prolonged labor
cord round the neck
placenta previa; death of mother
aspiration of blood
• Criminal:
– strangulation with cord
– drowning in milk or water
– omission to feed
POSTMORTEM EXAMINATION OF
FETUS AND NEWBORN
• The cause of death should be established on
basis of:
– obstetrical medical history
– clinical examination of child with laboratory tests
– postmortem examination:
• gross examination,
• histological examination
• examination of afterbirth
EXTERNAL EXAMINATION OF
NEWBORN AND FETUS
Differences
• Signs of death:
– rigor mortis
– livor (hypostatic blotch) putrefaction
• Measurements of head, chest, abdominal circumferences,
length and weight; facial measurements
• Skin-color; elasticity of subcutaneous tissue
• Examination of head
– pupillary membrane, development of ear and nose cartilage
• Umbilical cord
– localization, changes of proximal and distal end of umbilical cord
External examination of the Newborn
and Fetus
• Rigor mortis (stiffness of death; caused by chemical
change in the muscle after death)
– Occurs as ATP is depleted, preventing relaxation of muscle
fibers begins to develop several hours after death; rigor
initially develops in the jaw,
• Followed by upper and lower extremities
– in newborn occurs very early (even 20 min after death)
• Infection, terminal seizure, electrocution, strenuous
exercise or high body temperature may cause rigor to
develop more rapidly
• In hot weather, rigor dissipates more rapidly; in cold
weather, rigor may persist longer
• Livor
(hypostatic blotch, settling of the blood in the lower portion of the
body; intensity of color depends upon the amount of reduced
hemoglobin)
• Initially, livor is due to blood settling within vessels, and thus can
shift with movement of the body and will blanch with pressure
later, blood will hemolysis and diffuse out of the vascular space; at
this point, livor is fixed; it will not shift with movement of the body
and is nonblanchable
• Weaker than in adults without possibility of dislocation even after 5
hours after death
• Lack of livor in full termed newborn- suspicion of anemia,
hemorrhage more intensive livor- in full termed newborn occurs in
case of cyanosis in carbon monoxide poisoning, livor is cherry red in
color
Livor Mortis
• Discoloration does not occur in the areas of
the body that is in contact with the ground or
another object
• As the vessel wall become permeable due to
decomposition, blood leaks trough them and
stains the tissue
– fixation of hypostasis
External examination of newborn and
fetus
• Postmortem drying of the tongue and mucosal
membranes darkens the tissues, imparting a
Pseudohemorrhagic appearance
• drying up- lips, ends of fingers, auricles
External examination of newborn and
fetus
• Putrefaction (decomposition of proteins) it results in breakdown of
cohesion between tissues
– Green discoloration of the lower abdomen, due to overgrowth of
colonic bacteria
– Green-black discoloration and swelling of the face and neck
– Red-brown purge fluid may extrude from the nose and mouth; this
should not be confused with blood
• Gas formation causes diffuse swelling of the body, most noticeable
in the abdomen
• Skin slippage and blistering; hair slippage from the scalp
• Marbling occurs due to breakdown of hemoglobin within blood
vessels
• In infants occur very early; firstly near subcutaneous blood vessels
and livors
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Measurement of head, chest, abdominal
circumference, length and weight; facial
measurement
Head circumference,
Mento-occipitaldiameter,
Fronto-occipital diameter,
Biperietal diameter
• LENGTH : crown-heel
(from the vertex to heel with feet situated
perpendicular)
Facial measurement
• Persistent pupillary membrane (PPM) is a
condition of the eye involving remnants of a
fetal membrane that persist as strands of
tissue crossing the pupil;
– It exists in the fetus as a source of blood supply for
the lens
– It normally atrophies from the time of birth to the
age of four to eight weeks;
• PPM occurs when this atrophy is incomplete
Umbilical cord-localization, proximal
and distal end of cord
• The degree of fetal maturity
• Wet or dried, smooth, with knots or without
• Features of inflammation in proximal end of
cord - distal end of cord- regular and uniformly
cut
• Irregular end of cord-delivery without medical
help
Internal examination of newborn and
fetuses: main differences
• Autopsy of head: special techniques opening of scull,
caput succedaneum
• „collar incision” (y-shaped, with sharp scalpel) with
bypass of umbilicus
• Opening of trachea in situ
• Pulmonary water loading test, gastro-intestinal test
• Estimation of abdominal cavity (30-40 ml of blood
leads to death)
• Estimation of patency of Botall’s duct and foramen
ovale
Autopsy of Head
• CAPUT SUCCEDANEUM (pressure of the
presenting part of the scalp against the dilating
cervix during delivery; management...)
• Description of fontanells
• Bones defects of scull (due to injury or congenital
abnormalities)
• Special techniques opening the scull
• Examination of dura mater, cerebral falx,
tentorium of the cerebellum, subdural hematoma
Caput Succedaneum
• An abnormal collection of fluid under the
scalp on top of the skull that may or may not
cross the suture lines, depending on the size
• Pressure on the presenting part of the fetal
head against the cervix during labor may
cause edema of the scalp
• This diffuse swelling is temporary and will be
absorbed within 2 or 3 days
Different methods opening the scull
• „basket” incision
• „butterfly” opening of scull
• with creating two large bone flaps
Butterfly
• this method is superb for demonstration of
posterior fossa abnormalities
WITH CREATING TWO LARGE BONE
FLAPS
• To preserve the superior sagital sinus
– the incision 1 cm lateral on both sides of the
midline, preserving sagital sinus between
¨Collar Incision¨ with by pass of
umbilicus:
• The incision is roughly y-shaped
• It begins at the shoulders, anterior to the
acromial process
• The upper limbs of incision penetrate to the ribs
and meet at the level of the xiphoid process
• The descending limbs of the incision extends
along the midline from the xyphoid process
• Above the umbilicus the incision divides towards
the inguens
Examination of oral cavity and the
opening of trachea in situ
• The examination and description of oral cavity,
pharynx and upper part of larynx (foreign
bodies, injures, anatomical abnormalities)
• Opening of trachea in situ (we stick knife in
the middle of trachea; contents of larynx,
trachea)
• HYDROSTATIC PULMONARY WATER-LOADING
TEST
• HYDROSTATIC GASTRO-INTESTINAL TEST
Still Birth
• When child (born after 28 weeks) did not
breath or show any sign of life at any time
after being expelled from the mother
• Common causes are prematurity, anoxia, birth
trauma especially intracranial hemorrhage
due to excess molding, placental abnormality
Dead Birth
• When child has died in the utero and shows
one of the following signs after complete birth
• Rigor mortis at delivery
• Maceration (aseptic autolysis after 3-4 days in uterus
filled with amniotic fluid and no air); the earliest sign of
maceration is skin slippage, which can be seen in 12
hours after death in utero; the body of the macerated
fetus is soft, flaccid, and flattens out when placed on a
level surface; it has a sweetish disagreeable odor.;
• Mummification: is the condition in which the fetus
dries up, shriveled in the uterus.; it occurs when fetus
dies from deficient supply of blood, when the liquor
amni is scanty
MACERATION OF FETUSES
Interuterine Maceration – Softening
due to decomposition
• iIntrauterine aseptic autolysis of body
– fetal tissues get soaked with amniotic fluid, blood
serum,
• Tissue enzymes and acid properties of calcium
soaps in meconium
– lack of specific smell of putrefaction
– the lesions are located uniformly
– advanced lesions- head as fluctuating cyst with
palpable separated bones of scull
Macerated stillborn fetus
• Death was due to a true knot with obstruction
of venous return from the placenta 10 cm
from the abdomen. Total length was 65 cm.
Note the marked congestion of the cord distal
to the knot
Signs of Live birth
• Shape of chest
– the position of diaphragm- found at the level of 4th or 5th rib; if
no
• Respiration, 6th or 7th rib after breathing
• Lungs- after respiration, volume is increased, margins become
rounded, consistency becomes soft, spongy, elastic and crepitant;
the hydrostatic test by placing the lung tied at bronchi into water- if
floats suggests respiration but an unexpanded lung may float from
putrifaction and the expanded lung may sink from disease like acute
edema, pneumonia
• Stomach- air is swallowed into the stomach during respiration
• other signs of live birth- caput succedaneum, air in GI tract, clothed
body
Pulmonary Water Loading Test
• In cases suspected for infanticide; was the child alive
after birth ?
• After the opening of abdominal cavity we describe the
diaphragm,
• The appearance of lungs, pleura
• We open pericardial sac
• Ligation of stomach beneath the diaphragm
• Evisceration of thorax with description of surface of the
lungs, color of the lungs; gas bubbles, marble-like
pattern of the surface
– pulmonary water-loading test
• Put all organs into the water- they sink or float on
the surface of the water
• Cut the trachea and bronchi (contents)
• Cut off the thymus
• Estimation of patency of Botall’s duct
• Cut off lungs and put them into water
• Classical examination of lungs
• Cut off each lobe and put into water
• Cut the lungs into slices, pieces and put into
water
False Positive
• Putrefaction gas
• State after resuscitation
False Negative
• Infanticide when placental circulation is still
present
• In pre termed newborns- insufficiency of
respiratory centers or respiratory muscles
• Disruption of placental circulation during
delivery with aspiration of amniotic fluid
• Congenital abnormalities and obstacle in
respiratory tract
Gastrointestinal Test
• In cases suspected for infanticide
• To check if the child was born alive or death
• After ligation of stomach, small and large
intestine we put into the water
• Check which part of gastrointestinal part floats
on the water surface
• Positive result of the test:
– Newborn breath after delivery
– After resuscitation of newborn
– Putrefaction lesions
• Negative result of test:
• Stomach and intestine sink in water – child
died before the first breath or delivered dead
– POSITIVE RESULT OF GASTROINTESTINAL AND
PULMONARY WATER-LOADING TEST child breath
after delivery
– POSITIVE RESULT OF GASTROINTESTINAL AND
NEGATIVE PULMONARY WATER-LOADING TEST –
child breath after delivery
AUTOPSY IN FAT EMBOLISM
The Presence of Fat Emboli Suggest
That injury of body was intravital
• Fat from the bone marrow and subcutaneous
tissue
• Fat from organs
• Not emulsificated fat from blood serum
– during autopsy we take some tissue samples from
brain, lungs, myocardium and fix them in formalin
– we can’t put them into the alcohol- it dissolves the fat
• Fat emboli- requires specialized techniques
(frozen sections, SUDAN III staining)
Autopsy in Pneumothorax
Causes of pneumothorax:
• Primary
– SPONTANOUS PNEUMOTHORAX
– TRAUMATICPNEUMOTHORAX
- blunt trauma or penetrating injury to
– the chest wall
- rib fracture
- rupture of esophagus
– young slim man congenital sub pleural bull
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congenital cystic adenomatoid malformation
chronic obstructive pulmonary disease
neoplasm of pleura
tuberculosis
sarcoidosis
in children, additional causes include measles, inhalation of a foreign body
• CT scan of the chest showing a pneumothorax
on the person's left side
• The air-filled pleural cavity (black) and ribs
(white) can be seen
• Complications of pneumothorax:
– CT scan of the chest showing a pneumothorax on the person's
left side
– the air-filled pleural cavity (black) and ribs (white) can be seen
• Recurrence- many people who have had one pneumothorax have
another, usually within three years of the first
• Persistent air leak- air may sometimes continue to leak if the
opening in the lung won't close; surgery may eventually be needed
to close the air leak
• Low blood oxygen levels (hypoxemia)
• Cardiac arrest
• Respiratory failure
• Shock
When Pneumothorax is suscpected we
do the test
• After surgical procedures in the chest in tuberculosis
• During preparation of cervical integument and chest we can
not cause the injury intercostal space
• We preparate integument from the second intercostal
space to xiphoid process to form a kind of pocket and we
pour water into it
• We tap the intercostal spaces with knife and we observe if
any gas bubbles get out onto the surface of water
• After cutting off the sternum we pour water into pleural
cavity in which the pneumothorax was diagnosed
• Through the trachea we flow some air and observe where
the place of injury is
Sudden Infant Death Syndrome SIDS
• „sudden death of an infant under 1 year of
age which remains unexplained after a
thorough case investigation, including
performance of a complete autopsy,
examination of death scene, and review the
clinical history”
• Is the leading cause of death between age 1
month and 1 year in developed
• Countries
„cot death” -cause ???
• Recognission after the excluding alternative
causes of death
SIDS – Postmortem abnormalities
detect is cases of sudden unexpected
infant death
• Multiple petechie on the thymus, viceral and
parietal pleura, and epicardium
• Pulmonary congestion
• Astrogliosis of the brain stem and cerebellum
• Hypoplasia of the arcuate nucleus
• Extramedullaryhematopoiesis
• No symptoms
• Babies who die of SIDS do not appear to suffer
or struggle
• Autopsy - not able to confirm a cause of death