Evaluating Perinatal Asphyxia Cases
By Robert A. Zielke
One to two newborns in every 1,000 births develop cerebral palsy as a result
of brain damage. J.M. FREEMAN, NATIONAL INSTITUTES OF HEALTH, PUB. NO. PB87172581,
PRENATAL AND PERINATAL FACTORS ASSOCIATED WITH BRAIN DISORDER (1985). Tragically,
this disabling motor disorder is sometimes preventable. In these cases, cerebral
palsy can usually be traced to an episode of perinatal asphyxia, or lack of
oxygen during the birth process.
Proving cerebral palsy resulted from mishandling of the birth process is
difficult. Defendants will argue the condition resulted from unpreventable causes
during gestation and that no form of medical intervention could have remedied
the situation. They will point to statistics showing that the number of cerebral
palsy cases has remained unchanged for the last 20 years, that perinatal asphyxia
accounts for only about 15 percent of these cases, and that the cause of cerebral
palsy is unknown in the remaining 85 percent of cases. AMERICAN COLLEGE OF OBSTETRICIANS
AND GYNECOLOGISTS (ACOG), TECHNICAL BULL. NO. 132, INTRAPARTUM FETAL HEALTH
RATE MONITORING (1989); ACOG, TECHNICAL BULL. NO. 163, Fetal and Neonatal Neurologic
Injury (1992).
For these reasons, case evaluation is critical; you should accept only those
cases in which there is strong evidence of a lack of oxygen coupled with a health
care providers failure to act in the face of this emergency. This article
discusses what to look for when assessing these cases and which experts can
assist.
Causation
This is a key issue in birth injury cases, as in nearly all medical negligence
actions. Therefore, until you can answer the question of whether the brain damage
was preventable, you should delay evaluating negligence theories.
Various criteria identify infants who were brain damaged as a result of decreased
oxygen during labor and delivery: (1) severe acidosis - decreased alkali in
the blood and body fluids in proportion to the acid content - evidenced by a
blood pH of less than 7.0; (2) a five-minute or longer APGAR score of three
or less; (3) evidence of neurologic injury - seizures - within the first 24
hours of life; and (4) damage to other organs - such as the kidneys - that is
consistent with decreased oxygen. ACOG, TECHNICAL BULL. No. 163.
Be aware of two types of acidosis: (1) metabolic, caused by accumulation
of excess acids or by abnormal losses of fixed base, and (2) respiratory, caused
by retention of carbon dioxide. Since respiratory acidosis does not necessarily
lead to brain damage, strong evidence of metabolic acidosis is needed.
CT or MRI scans are important in ruling out other causal events. Retain a
neuroradiologist to advise whether the injury evidenced on the MRI occurred
to a mature brain, indicating birth asphyxias the cause of damage. One key radiological
pattern indicating injury before birth is a finding of periventricular leukomalcia
(PVL), a hypox-ischemic injury that affects the area surrounding the ventricles.
If hypoxic event occurred between 27 and 34 weeks gestation - before
the brain is fully mature - damage to the periventricular region is a classical
finding. It is rare to find PVL after 34 weeks gestation. Thus, the 40-week,
or full-term, asphyxia case should not include evidence of PVL.
The entire course of the pregnancy must be evaluated for evidence of events
that could have produced brain damage. The birth asphyxia case should not include
any evidence of decreased fetal movement or trauma during the pregnancy. Any
fetal ultrasound examinations should be normal both for anatomy and for fetal
size to gestational age.
Evaluate the mothers habits during the pregnancy. Generally, defendants
will assert a mothers smoking had caused placental damage that decreased
fetal strength. Also look for maternal alcohol consumption, nutritional status,
medication exposure, and illicit drug use.
Negligence
Strong evidence of negligence is needed to convince a jury of liability.
Obstetrical negligence consists of inappropriate or no intervention in the face
of clear evidence of fetal distress, which is generally diagnosed from electronic
fetal heart monitoring.
You must understand the basics of interpreting findings from a fetal heart
monitor. A significant indicator of distress is a heart rate outside the normal
range of 120 to 160 beats per minute. Other common indicators include late decelerations
and decreased short- or long-term beat-to-beat variability.
A late deceleration is a decrease in the fetal heart rate after a uterine
co class="article"ntraction. Variability describes the fluctuations that normally
occur in the fetal heart rate as recorded on a heart strip. Since the heart
rate is controlled by the brain, any changes that produce anoxia or ischemia
will cause a decrease in variability.
The pattern on the monitor strip must be distinct enough to show enough ominous
signs that the jury will understand what a correct diagnosis would have been
and believe a reasonably prudent physician would have intervened to prevent
catastrophic brain damage.
Obstetrical negligence can take two basic forms: (1) failure to perform fetal
testing to assess acidosis or asphyxia; and (2) failure to perform or timely
perform a cesarean section.
Fetal scalp pH testing measures the acid/base status of the baby and is highly
useful in determining whether the child needs to be delivered immediately. For
this test, a blood sample is obtained from the babys scalp and sent to
the lab, which reports back the pH of the blood.
Another test involves stimulating the childs scalp while the child
is in the birth canal. If the child is not acidotic, this stimulation should
cause an acceleration in the fetal heart rate. If it does not, the fetus is
generally in distress. To determine if an acceleration occurs, scalp stimulation
must be performed between contractions when the fetal heart rate is at its baseline.
When sufficient signs of fetal distress are present, reasonable care mandates
that a cesarean section be performed to end the perinatal asphyxia and, hopefully,
save the fetus and its neurologic function. A cesarean section is typically
performed on an emergency basis to end the perinatal asphyxia as soon as possible.
Do not overlook other factors that increase the risk of fetal distress; a
post-term pregnancy, abruption of the placenta, placental abnormalities, and
decreased amniotic fluid indicating placental insufficiency.
Experts
A perinatologist, an expert in high-risk pregnancies and deliveries, can
evaluate the management of labor and offer his or her opinion regarding the
cause of the childs injury. As mentioned, a neuroradiologist can explain
and interpret CT and MRI findings. In the event that an MRI has not been performed,
the neuroradiologist can perform one even years after the event to help determine
the cause of the brain injury.
A pediatric neurologist can address causation issues and demonstrate to jurors
that the type of cerebral palsy that the child exhibits is consistent with your
theory of birth asphyxia. A developmental pediatrician can explain the profound
nature of the brain damage and the childs current level of functioning
compared to his or her chronological age. IN profound cases of brain damage,
it is common to see a 4-year old child functioning at or below the level of
a 1-year old.
A rehabilitation nurse can formulate a life care plan for future medical
care needs and the cost of future care. An economist can then calculate the
cost of future medical services and wage loss, reducing those amounts to their
present value.
Birth injury cases require careful evaluation and a thorough analysis of
the medical issues. Look for persuasive evidence of profound birth asphyxia
and the obstetricians failure to timely assess fetal well-being and deliver
the child.
Successfully prosecuting these cases requires understanding pregnancy management
and the pathophysiology surrounding multiple causal events producing brain damage.
Preparation may be extensive. For individuals permanently and severely disabled
by an otherwise preventable injury, however, your efforts will be vitally important.
Zielke, 10 Professional Negligence Law Reporter 114 - July 1995
