2. and fetus, that is, situations in which without medical
intervention both the mother
and the child will die but with intervention the mother alone can
be saved.1 They
Alan Vincelette, PhD, is an associate professor of philosophy at
St. John’s Seminary
in Camarillo, California.
The views expressed in the NCBQ do not necessarily represent
those of the editor, the
editorial board, the ethicists, or the staff of The National
Catholic Bioethics Center.
1. Colloquium Participants, “Medical Intervention in Cases of
Maternal–Fetal
Vital Conflicts: A Statement of Consensus,” National Catholic
Bioethics Quarterly 14.3
(Autumn 2014): 477–489. All subsequent references to this
article will appear as in-text
paragraph numbers. See also Peter Cataldo and Thomas
Goodwin, “Early Induc-
tion of Labor,” in Catholic Health Care Ethics: A Manual for
Ethics Committees, ed.
Maternal–Fetal Conflict
and Periviability
Alan Vincelette
402
3. concluded, “Interventions that surgically dismember a live fetus
in order to remove it
from the uterus are impermissible,” but in situations involving a
subsequent pregnancy
in a woman with a history of peripartum cardiomyopathy,
“medical induction of labor
prior to fetal viability to eliminate a grave and present danger
posed by the interaction
of the normally functioning placenta with the weakened heart of
the mother can be
consistent with directive 47 [of the Ethical and Religious
Directives for Catholic Health
Care Services] and justified in accord with the principle of
double effect” (nn. 16, 19).2
While it is impressive that a consensus on these issues could be
reached by a
distinguished group of moral theologians, it is not clear that this
statement can, in
the end, represent a broad consensus that is useful “for
developing clinical guidelines
for maternal–fetal vital conflict that are consistent with
Catholic Church teaching
and the medical standard of care” (n. 1).
Intention and the Moral Object
The consensus—that one can deplant the placenta attached to a
previable fetus
in order to save the life of a mother with peripartum
cardiomyopathy who under-
goes a subsequent pregnancy—tends to gloss over or ignore
some fundamental
issues regarding intention and the moral object, which divide
contemporary moral
theologians. The signatories appeal to the principle of double
4. effect, which pertains
to actions that have both a good effect and a bad effect. It
allows such an action to
be performed if (1) the rationally chosen object of the act is
good or neutral, (2) the
agent directly intends only the good effect and not the bad
effect, (3) the good effect
is not achieved by means of the bad effect, and (4) the good
effect is proportionate to
the bad effect (n. 12). The signatories conclude that, in the
described case, medical
induction of labor would be licit because “the remote end of the
act—which is to
eliminate the grave and present danger by deplanting the
placenta from the uterus
in order to save the mother’s life—is the intended good effect;
the death of the child
is the foreseen but unintended bad effect” (n. 19, original
emphasis).
It is important to notice that the signatories construe the
intention of the act
as merely the ultimate or remote end of the agent, that is, the
ultimate purpose the
Edward Furton et al. (Philadelphia: National Catholic Bioethics
Center, 2009): 111–118;
Ron Hamel, “Early Pregnancy Complications and the Ethical
and Religious Directives,”
Health Progress 93.3 (May–June 2014): 48–56; Nicanor Pier
Giorgio Austriaco, “Resolving
Crisis Pregnancies: Acting on the Mother versus Acting on the
Fetal Child,” National Catho-
lic Bioethics Quarterly 15.2 (Summer 2015): 207–208; Peter
Cataldo et al., “Deplantation
of the Placenta in Maternal–Fetal Vital Conflicts: A Response
5. to Bringman and Shabanow-
itz,” National Catholic Bioethics Quarterly 15.2 (Spring 2015):
241–250; John Di Camillo,
“Induction of Labor and Vital Conflicts: Caution with Double
Effect,” Ethics and Medics 40.6
(June 2015): 1–4; John Di Camillo and Edward Furton, “Early
Induction and Double Effect:
Advancing the Discussion on Vital Conflicts,” National
Catholic Bioethics Quarterly 15.2
(Summer 2015): 251–261; and Meredith White and Nicanor Pier
Giorgio Austriaco, “The Use
of Pre-Term Induction in Crisis Pregnancies: The Drowning
Lifeguard–Drowning Swimmer
Case,” Angelicum 92.1 (2015): 115–130.
2. See US Conference of Catholic Bishops, Ethical and
Religious Directives for Catholic
Health Care Services, 5th ed. (Washington, DC: USCCB, 2009).
–Fetal conFlict and PeriViability
403
agent is trying to achieve. Yet such a view is not universally
agreed on by Catholic
moralists, many of whom would argue that one must intend not
only the ultimate
end of the act but also the specific means of achieving it, that
is, the moral object
or proximate end.3 While the signatories note that the intention
may or may not
coincide with the moral object or proximate end (n. 12), they do
not believe that the
proximate end is necessarily part of one’s intention, whereas
6. other Catholic ethicists
do. Stated more philosophically, for the signatories any overlap
of the remote and
proximate ends would be accidental, not essential, because the
agent’s deliberate
purpose includes both ends.
Additionally, the signatories assert that “the moral object or
proximate end
of the act which is the triggering of uterine contractions to
deplant the placenta in
order to eliminate the placenta’s pathology-inducing interaction
with the weakened
heart of the mother is good or at least morally neutral”; that is,
the “exterior act is
described as the medical induction of labor prior to fetal
viability by triggering the
uterus to contract” (n. 19). Here again, there is considerable
debate among Catholic
ethicists on how an exterior act should be defined. For example,
Elizabeth Anscombe
recognizes that it is tricky to describe what exactly one is doing
when one acts, as
there are different levels of description.4 The signatories seem
to assume that the
agent merely acts directly on the mother’s placenta or uterus,
not on the fetus,5 but
3. Although I am not in favor of this position, it does have some
notable defenders,
including Kevin Flannery, “What Is Included in a Means to an
End?,” Gregorianum 74.3 (1993):
499–513; Benedict Guevin, “Vital Conflicts and Virtue Ethics,”
National Catholic Bioethics
Quarterly 10.3 (Autumn 2010): 471–480; Thomas Cavanaugh,
“Double-Effect Reasoning,
7. Craniotomy, and Vital Conflicts,” National Catholic Bioethics
Quarterly 11.3 (Autumn 2011):
453–464; Kevin Flannery, “Vital Conflicts and the Catholic
Magisterial Tradition,” National
Catholic Bioethics Quarterly 11.4 (Winter 2011): 691–704;
Matthew O’Brien and Robert
Koons, “Objects of Intention: A Hylomorphic Critique of the
New Natural Law Theory,”
American Catholic Philosophical Quarterly 86.4 (Fall 2012):
655–703; and Steven Jensen,
“Causal Constraints on Intention: A Critique of Tollefsen on the
Phoenix Case,” National
Catholic Bioethics Quarterly 14.2 (Summer 2014): 273–293.
4. See Elizabeth Anscombe, Intention (Ithaca: Cornell
University Press, 1957), 34–49,
nn. 22–27; and Philip Reed, “How to Gerrymander Intention,”
American Catholic Philosophi-
cal Quarterly 89.3 (Summer 2015): 441–460.
5. Cataldo et al. put it this way in “Deplantation of the
Placenta,” a later paper: “The
first condition [of the principle of double effect] is that the
rationally chosen object of the
act must be morally good in nature or at least not be
intrinsically evil. The act of inducing
labor is not intrinsically evil because it mirrors and augments
the natural process of labor by
which all the contents of the uterus are evacuated when the
retention of those contents would
be harmful to child or mother. The intelligibility of labor is not
defined by the evacuation of
one or another specific component of the in utero contents, but
rather by the evacuation of
all the contents including the placenta. Therefore, in any given
case of early induction for the
8. pathological interaction in PPCM+P, whether the death of the
fetus occurs after the separa-
tion of the placenta from the uterus, together with and at the
same time as the separation,
or whether it occurs prior to the separation makes no difference
to the moral object of the
induction, because the death of the fetus is not the chosen
object or the specific means used to
eliminate the pathological interaction. In all three situations, the
death of the fetus remains a
The NaTioNal CaTholiC BioeT
404
not all will agree, especially those who include the integral
nature of the act as part
of its structure.6
Moreover, the signatories exclude any immediate consequences
of the act from
the proximate end, but this too (the so-called problem of
closeness) is not uncontro-
versial. As Anscombe notes, an arsonist cannot readily be
excused on the grounds
that he did not intend to kill anyone in a fire he set.7 She is
building on the work of
St. Thomas Aquinas, who asserts that “if evil is always, or, as it
were, in most cases,
associated with the good that is intended for itself, one is not
excused from sin, even
if one does not intend the evil for itself.” 8 In fact, Aquinas
even applies the principle
of closeness to the unintentional harm done to a fetus: “One
9. who strikes a pregnant
foreseen but unintended and indirect bad effect of the act of
induction of labor, whose nature
is not intrinsically evil” (249). See also Austriaco (“Resolving
Crisis Pregnancies,” 207) and
Di Camillo and Furton (“Early Induction and Double Effect,”
252), who argue that induction
of labor is not a direct attack on the fetus and not intrinsically
evil, even though they concede
the placenta is a vital organ of the child.
6. Stephen Brock, “Veritatis Splendor §78, St. Thomas, and
(Not Merely) Physical
Objects of Moral Acts,” Nova et Vetera 6.1 (Winter 2008): 1–
62; Steven Long, “ Veritatis
Splendor §78 and the Teleological Grammar of the Moral Act,”
Nova et Vetera 6.1
(Winter 2008): 139–156; Jean Porter, “Choice, Causality, and
Relation: Aquinas’s Analysis of
the Moral Act and the Doctrine of Double Effect,” American
Catholic Philosophical Quarterly
89.3 (Summer 2015): 479–504. These authors might challenge
the narrow interpretation that
an act of inducing labor can be defined in isolation from the
vital bond between the fetus and
placenta and the mother.
7. Elizabeth Anscombe asserts, “The suggestion is that that is
all I am doing as a means
to my end. . . . ‘Nonsense’, we want to say, ‘doing that is doing
this, and so closely that you
can’t pretend only the first gives you a description under which
the act is intentional. . . . All
this is relevant to our pot-holer only where the crushing of his
head is an immediate effect of
10. moving the rock. . . . Where the crushing is immediate you
cannot pretend not to intend it if
you are willing to move the rock. . . . [But] consider the case
where the result is not so immedi-
ate—the rock you are moving has to take a path after your
immediate moving of it, and in the
path it will take it will crush his head. Here there is indeed
room for saying that you did not
intend that result, even though you could foresee it.” “Action,
Intention and Double Effect,”
Proceedings of the American Catholic Philosophical Association
(1982): 23–24, original
emphasis. Thus Anscombe appeals to the principle that one
cannot exclude the guaranteed
immediate consequences of an action from being part of the
intended act itself, though one can
exclude possible but not likely effects. Similar views occur in
Denis Sullivan, “The Doctrine of
Double Effect and the Domains of Moral Responsibility,”
Thomist 64.3 (July 2000): 423–448;
and Luke Gormally, “Intentions and Side-Effects: John Finnis
and Elizabeth Anscombe,” in
Reason, Morality, and Law: The Philosophy of John Finnis, ed.
John Keown and Robert P.
George (Oxford, UK: Oxford University Press, 2013), 93–108.
Such thinkers might argue
that since the death of the fetus results as an immediate
consequence of the induction of labor
before viability, the death of the fetus is either part of one’s
intention or part of one’s act. I
tend to side with the latter position.
8. “Sed si semper vel ut in pluribus adiungatur malum bono
quod per se intendit, non
excusatur a peccato, licet illud malum non per se intendat.”
Thomas Aquinas, On Evil 1.3.15.
11. See also Aquinas, Summa contra gentiles 2.4–6, and Summa
theologiae I-II.20.5 and I-II.73.8.
Translations from the Latin are by the author.
–Fetal conFlict and PeriViability
405
woman does an illicit deed. And therefore if the death, either of
the woman or the
animated fetus, results, one will not be excused from the crime
of homicide, especially
since death readily results from such a blow.” 9
The Morally Safest Course
When formulating clinical guidelines for Catholic health care
institutions, it
would presumably be best to start with the morally safest course
of action, which
is least likely to lead to sin and most likely to achieve broad
consensus. With this
in mind, I make an alternative proposal here that is prudentially
safe, considers the
interests of both mother and child, and could achieve a much
broader consensus than
the 2014 proposal, even garnering the assent of those who hold
disparate views on
some of the disputed issues noted above. Specifically, in a
pregnancy where a grave
and present danger is posed by the interaction of the normally
functioning placenta
with the weakened heart of the mother, medical induction of
labor can be consistent
12. with directive 47 and justified in accord with the principle of
double effect if the
fetus is developmentally advanced enough to have at least a fair
chance of survival.
One can debate exactly what “fair chance of fetal survival”
means, but perhaps the
simplest way to explicate this is to say that inducing labor can
be morally justifiable
once a fetus has reached the point of development where its
chance of surviving
induction is at least 50 percent, that is, where its viability is at
least a distinct pos-
sibility (periviability).10
While each particular case would have to be looked at
individually, taking into
account fetal weight, the mother’s left ventricular ejection
fraction, and other factors,
in general this proposal would mean bringing a fetus to at least
twenty-four weeks
of gestation.11 Arguably, the fetus should be brought to at least
twenty-six weeks
9. “Ille qui percutit mulierem praegnantem dat operam rei
illicitae. Et ideo si sequatur
mors vel mulieris vel puerperii animati, non effugiet homicidii
crimen, praecipue cum ex tali
percussione in promptu sit quod mors sequatur.” Aquinas,
Summa theologiae II-II.64.8 ad 2.
10. See the similar, though not identical, concept of
periviability developed by obstetri-
cians in T. N. Raju et al., “Periviable Birth,” Obstetrics and
Gynecology 123.5 (May 2014):
1083–1096.
13. 11. On fetal mortality and morbidity at various gestational ages,
see V. Fellman et al.,
“One-Year Survival of Extremely Preterm Infants after Active
Perinatal Care in Sweden, ”
JAMA 301.21 (June 3, 2009): 2225–2233; K. L. Costeloe et al.,
“Short Term Outcomes after
Extreme Preterm Birth in England: Comparison of Two Birth
Cohorts in 1995 and 2006,”
British Medical Journal 345, e-pub December 4, 2012, e7976,
doi: 10.1136/bmj.e7976;
F. García-Muñoz Rodrigo et al., “Morbidity and Mortality in
Newborns at the Limit of Viability
in Spain: A Population-Based Study,” Anales de Pediatría 80.6
(June 2014): 348–356; P. Y.
Ancel et al., “Neonatal Outcomes of Very Low Birth Weight
and Very Preterm Neonates: An
International Comparison,” JAMA Pediatrics 169.3 (March
2015): 230–238; S. Bolisetty et al.,
“Preterm Infant Outcomes in New South Wales and the
Australian Capital Territory,” Journal
of Pediatrics and Child Health 51.7 (July 2015): 713–721;
Matthew Rysavy et al., “Between-
Hospital Variation in Treatment and Outcomes in Extremely
Preterm Infants,” New England
Journal of Medicine 372.19 (May 7, 2015): 1801–1811; Barbara
Stoll et al., “Trends in Care
Practices, Morbidity, and Mortality of Extremely Preterm
Neonates, 1993–2012,” JAMA 314.10
406
of gestation, when it would have around a 75 percent chance of
14. surviving and a
75 percent chance of not having a severe health impairment. At
twenty-four weeks, the
fetus’s chance of being free of a major impairment would be
only around 25 percent.
While there would be more agreement on not intentionally
killing the fetus—
hence a broader consensus that the act is in accord with the
principle of double
effect—it might be argued that such a proposal does not
adequately consider the
mother’s interests and might too facilely risk her death. Yet
according to current
scientific data, this is not necessarily the case: the latest studies
suggest that the current
mortality rate for mothers with peripartum cardiomyopathy who
undergo a subse-
quent pregnancy is typically 10 to 20 percent.12 If the mother
dies, as happens rarely,
her death typically occurs two to three months after delivery
and, in one case, two
years after delivery.13 So the chance a subsequently pregnant
mother with peripartum
cardiomyopathy will survive to carry her baby to at least
twenty-four weeks’ gestation
(September 2015): 1039–1051; and Tracy Manuck et al.,
“Preterm Neonatal Morbidity and
Mortality by Gestational Age: A Contemporary Cohort,”
American Journal of Obstetrics and
Gynecology 215.1 (July 2016): 103.e1–103.e14, doi:
10.1016/j.ajog.2016.01.004.
12. Uri Elkayam et al., “Maternal and Fetal Outcomes of
Subsequent Pregnancies
15. in Women with Peripartum Cardiomyopathy,” New England
Journal of Medicine 344.21
(May 2001): 1576–1571; K. Sliwa et al., “Outcome of
Subsequent Pregnancy in Patients
with Documented Peripartum Cardiomyopathy,” American
Journal of Cardiology 93.11
(June 2004): 1441–1443; James D. Fett, Len G. Christie, and
Joseph G. Murphy, “Outcomes of
Subsequent Pregnancy after Peripartum Cardiomyopathy: A
Case Series from Haiti,” Annals of
Internal Medicine 145.1 (July 4, 2006): 30–34; M. Habli et al.,
“Peripartum Cardiomyopathy:
Prognostic Factors for Long-Term Maternal Outcome,”
American Journal of Obstetrics and
Gynecology 199.4 (October 2008): 415.e1–415.e5, doi:
10.1016/j.ajog.2008.06.087; James
D. Fett, Karie L. Fristoe, and Serena N. Welsh, “Risk of Heart
Failure Relapse in Subsequent
Pregnancy among Peripartum Cardiomyopathy Mothers,”
International Journal of Gynecol-
ogy and Obstetrics 109.1 (April 2010): 34–36; Debasmita
Mandal et al., “Pregnancy and
Subsequent Pregnancy Outcomes in Peripartum
Cardiomyopathy,” Journal of Obstetrics and
Gynaecology Research 37.3 (March 2011): 222–227; and Uri
Elkayam, “Risk of Subsequent
Pregnancy in Women with a History of Peripartum
Cardiomyopathy,” Journal of the American
College of Cardiology 65.14 (October 2014): 1629–1636. These
studies indicate an overall
maternal mortality rate of around 8 percent when subsequent
pregnancies occur in women with
preexisting peripartum cardiomyopathy. The mortality rate
varies 5–25 percent between studies.
13. S. J. Whitehead et al., “Pregnancy-Related Mortality Due to
16. Cardiomyopathy,”
Obstetrics and Gynecology 102.6 (December 2003): 1328. Table
3 in Whitehead records only
two of 171 maternal deaths on account of peripartum
cardiomyopathy. One percent occurred
prior to delivery, but the study does not distinguish between
first or subsequent pregnancies.
Among peripartum cardiomyopathy cases with known intervals
correlating fetal delivery and
maternal death, 2 percent of mothers died prior to delivery, 48
percent died within forty-two
days of delivery, and 50 percent died between forty-three days
and one year postpartum.
Mandal (“Pregnancy and Subsequent Pregnancy Outcomes,”
225–226) records only one death
of a woman with pre-existing peripartum cardiomyopathy
during a subsequent pregnancy,
which occurred at twenty-seven weeks of gestation. Still,
Cataldo et al. (“Deplantation of
the Placenta,” 245–247) and Di Camillo and Furton (“Early
Induction and Double Effect,”
257–258) rightly note that, in spite of the rarity of
preparturitional maternal mortality, particular
factors may suggest to a clinician that a pregnant mother with
peripartum cardiomyopathy
is in great danger of dying. Ultimately, the question is what
bearing this has on a decision to
engage in the induction of labor of a previable fetus.
–Fetal conFlict and PeriViability
407
is at least 80 to 90 percent, though indeed there can be real
17. costs to the mother’s health
and even the need for a heart transplant. If physicians closely
monitor the mother’s
health after the birth, she has a very good chance of survival. In
such a situation,
arguably the morally safest course is to bring the fetus to
twenty-four to twenty-six
weeks’ gestation and thereafter closely monitor the mother’s
health, hoping for the
survival of both mother and child, of which there is a fair to
good chance. Certainly,
significant mitigating factors could reduce the moral culpability
of someone who
chooses to end a pregnancy by inducing labor prior to fetal
viability.
In some cases, clinical evidence will show that the mother is in
great danger
of dying. Yet might there not be an analogous situation, such as
being trapped under
rubble with one’s child, where one could free oneself only by
dislodging a large piece
of debris that would almost certainly crush and kill the child,
and where one should
out of love choose to await help and perhaps risk dying along
with the child rather
than freeing oneself and thereby causing the child to be killed?
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The Chemical and Biological Response Team (CBRT): Making a
Case for Being Better
Prepared for the Worst
Certain chemical and biological weapons are surprisingly
accessible, and should one be
released, it could pose an enormous public health threat. To
prepare for such an event and
minimize the damage it could cause, local government officials
have assembled a team of
doctors, nurses, and scientists called the Chemical and
Biological Response Team (CBRT). The
CBRT has been charged with medically responding to local and
state threats involving known or
suspected chemical or biological agents. In order to prepare the
members of the CBRT for this
responsibility, they have been undergoing extensive training;
part of this training has included
exercises in which they respond to mock threats.
The CBRT exercise we will follow involves a class of known
chemical weapons called
19. the lung-damaging agents. Many of these agents are easy to
obtain or manufacture, and are
therefore agents of concern for any counterterrorism efforts. We
follow the victims of exposure
to this gas for the first 6–24 hours after the simulated incident.
Unknown persons have released an unknown gas into a subway
station. Victims reported
detecting the scent of mown grass, after which they state they
began to suffer from “watering”
eyes and “runny” noses; a burning sensation in their nasal
cavities, mouths, and throats; and
difficulty speaking. The symptoms resolved about 30 minutes
after the victims were removed
from the subway station and taken to the street above. None of
the victims reported any difficulty
breathing during the incident.
Many of the victims who experienced symptoms immediately
following the release of the
gas agreed to be taken to the hospital to be monitored for
several hours. However, several of the
victims who did not experience severe symptoms declined to be
taken to the hospital.
In order to provide the healthcare workers at the hospital with
the information they
20. needed to treat the victims, the members of the CBRT were
trying to identify the lung-damaging
agent. The first clue in this scenario was the scent of “mown
grass,” which is characteristic of the
lung-damaging agent phosgene. Phosgene, also called carbonyl
chloride (COCl2), has many
legitimate uses, such as in the manufacturing of plastics and
pharmaceuticals, but it has also been
used during warfare and acts of terrorism. A second clue that
points to phosgene gas was found
in the victims’ initial symptoms—irritation of the mucous
membranes of the eyes, nose, mouth,
pharynx, and larynx. Phosgene reacts with the water in mucus to
produce the highly irritating
chemical hydrochloric acid, which causes inflammation of the
mucous membranes lining these
parts of the body.
A final clue is the fact that the victims did not report any
dyspnea, or difficulty breathing.
Phosgene tends to spare the conducting zone of the respiratory
tract below the level of the
larynx, and instead impacts the airways of the respiratory zone.
21. As a result, people who have
been exposed to phosgene gas tend to have no dyspnea initially,
but they then develop it 4–6
hours after exposure. Thus, the victims who lacked initial
symptoms and declined to be taken to
the hospital were still very much at risk for developing
respiratory problems.
Since the members of the CBRT had good reason to believe
that the agent released in part
one of the scenario was phosgene gas, they anticipated an influx
of patients to hospitals and
clinics with respiratory symptoms over the next several hours.
The CBRT opted to increase the
availability of medical staff, especially emergency personnel
and respiratory therapists, as well
as increasing the number of available mechanical ventilators.
The team also issued a mandate
that exposed patients presenting with any shortness of breath
were to be given supplemental
oxygen as soon as possible.
In the second part of the scenario, from 2–6 hours after the
incident, the witnesses
exposed to the gas began arriving at the hospital’s emergency
department. Many patients
22. complained of dyspnea, especially on exertion, a cough, and
chest pain. On physical exam and
chest x-ray, some of the patients were showing early symptoms
of respiratory disease; however,
some of the patients who presented were merely worried that
they might experience symptoms
but were currently asymptomatic.
The CBRT correctly anticipated that after the initial symptom-
free lag time, or latent
period, many victims exposed to phosgene would begin to seek
medical attention for respiratory
complaints. The preparations the team made were in
anticipation of the most dangerous
consequence of phosgene exposure: damage to the respiratory
membrane. When the respiratory
membrane is damaged, the permeability of the pulmonary
capillaries increases, resulting in large
volumes of fluid leaking from the capillaries into the space
surrounding the alveoli. This
condition of having fluid in the lungs is called pulmonary
edema, and it results in increased
alveolar surface tension and decreased pulmonary compliance.
One of the first treatments for
23. pulmonary edema is the delivery of supplemental oxygen to
counter the hypoxemia that these
patients experience.
Phosgene’s extended latent period, the time from gas exposure
to onset of symptoms, makes the
task of deciding which patients will need extensive care and
those who will not very difficult. To
ensure that each patient received appropriate care, the CBRT
put a system into place whereby
presenting patients were classified as either: 1) asymptomatic,
2) serious (patients experiencing
dyspnea without signs of pulmonary edema), or 3) critical
(patients with signs of pulmonary
edema).
As pulmonary edema worsens, the alveoli can actually fill with
fluid, which prevents gas
exchange from taking place altogether, causing hypoxemia and
hypercapnia. The severity of the
hypoxemia and hypercapnia can be determined by measuring the
arterial blood gases, which is
a test that evaluates arterial blood for its PO2 and PCO2. The
patients in our scenario had decreased
24. PO2 and increased PCO2, which was not surprising considering
that their alveoli were filled with
fluid.
In severe pulmonary edema, supplemental oxygen is often
inadequate to maintain the PO2
within a normal range, and mechanical ventilation is required to
restore oxygenation. Patients
exposed to phosgene require a type of mechanical ventilation
called high positive end–expiratory
pressure (high PEEP). High PEEP maintains a high pressure
inside the alveoli during expiration
so that intrapulmonary pressure remains higher than
atmospheric pressure. This prevents collapse
of the alveoli during expiration and facilitates gas exchange.
High PEEP is typically effective,
but if it is prolonged, it can lead to further complications. The
CBRT determined that patients
who were asymptomatic after the first 24 hours were not likely
to develop symptoms, and thus
could be released from the hospital. However, those still in the
“serious” or “critical” categories
would remain in a critical care unit until their measured level of
oxygenation was adequate. The
team recommended follow-up with a pulmonologist for all
25. patients requiring high PEEP
mechanical ventilation.
In this final part of the exercise, the asymptomatic patients
were released from the
hospital, and none returned with symptoms. Most patients in the
“serious” category who did not
require mechanical ventilation showed signs of improvement
after 3–4 days, and most in the
“critical” category that required high PEEP mechanical
ventilation showed signs of
improvements after 5–7 days. In the months that followed,
several patients developed asthma-
like symptoms and reported frequent dyspnea, for which they
sought medical attention. The
members of the CBRT anticipated that victims might need
follow-up care after release from the
hospital. Many victims exposed to phosgene are likely to
develop asthma-like symptoms from
irritation of the airways. Others would be expected to report
dyspnea on exertion for a year or
more following exposure. However, some of the lasting effects
from phosgene exposure might
26. not come from the gas itself, but rather from the treatment. High
PEEP greatly enhances survival
from severe pulmonary edema, but it is not without
complications. One of the most frequent
complications of PEEP is barotrauma—damage to the airways of
the respiratory zone from
high pressures. If the degree of barotrauma is significant, the
alveoli may be damaged, leading to
emphysema. However, even with these possible complications,
most patients without underlying
diseases will fully recover from phosgene inhalation, as long as
the situation is recognized and
treated aggressively from the start. The CBRT team concluded
that the exercise showed that their
recommendations could be used to write protocols for managing
a disaster involving exposure to
lung-damaging agents.
