Search for evidence of excessive postoperative facial swelling, because it indicates high tissue and venous pressure.
Finally, look for evidence that the
patient gave informed consent regarding
the possibility of POVL. The anesthesia
team often overlooks this issue in the
mistaken belief that this discussion is not
required. The patient’s consent is even
more critical with an elective procedure,
as it may well have changed his or her
decision to undergo the surgery.
You will need testimony from anesthesia, ophthalmology, and neuro-ophthalmology experts to establish
breach of the standard of care as well
as causation. Also consider retaining an
epidemiologist—this expert can present
evidence of the increased likelihood of
blindness when a patient is subjected to
long operating times in the prone position with at least one liter of blood loss.
The epidemiologist can show this
increased likelihood by analyzing the
National Inpatient Sample (NIS) database13 and comparing this data with data
in the ASA POVL Registry, which comes
from anonymously submitted reports of
POVL.14 The ASA Committee on Professional Liability established this registry
in 1999. With this pedigree, it is not surprising that the registry has been used
more to defend and defeat meritorious
cases than to educate anesthesiologists
on how to avoid blinding patients.15
If POVL is not predictable and thus
not preventable, as defendants routinely
contend, the frequency of POVL for various types of surgeries as reported in the
registry should be comparable to what’s
reported in the NIS database.
For example, one expert’s epidemio-logic analysis showed that the risk of
POVL is 22 to 23 times greater for spine
surgeries than for all other surgical
procedures. For patients who undergo
a spine surgery that lasts six hours and
involves a liter or more of blood loss,
their risk of POVL is approximately 135
to 175 times greater than that of patients
who undergo shorter spine surgeries
with less blood loss. For patients who
undergo a spine surgery that lasts at least
six hours and involves at least one liter
of blood loss, the risk of POVL is 2,655
to 3,319 times greater than the risk in all
patients undergoing surgery.
Defense Tactics
You can expect the defense to claim
that POVL is a rare, unpredictable, and
unpreventable problem. Defense experts
often are associated with the ASA registry and will claim that because its data
shows there is no known cause of POVL,
the injured patient cannot meet the burden of proof.
Be prepared to address the POVL registry both legally and scientifically. It has
some critical vulnerabilities:
• It was started for the purpose of limiting anesthesiologists’ professional
liability exposure.16
• It contains only data that is voluntarily reported to it by anesthesiologists, so there is a strong selection
bias in the data collected. It is not a
random data set or one that includes
all POVL patients.
• Neither the ASA nor the defense
experts will release the original
source data, which prevents anyone
from either replicating the results
or proving them wrong.
These factors expose the defense
experts to valid Daubert challenges.
For example, many of the cases in the
registry lack adequate data on baseline,
operative, and postoperative hematocrit
levels. Yet, even without this data, the
ASA’s POVL registry discounts the role
of hematocrit levels as a causative factor.
There is a similar lack of data regarding
patients’ baseline, operative, and postoperative blood pressures, as well as a
lack of data on patient positioning during surgery.
For a study to be scientifically valid, it
must be able to be replicated so its conclusions can be confirmed or refuted by
other researchers.17 Because the registry
will not release the underlying data and
the defense experts cannot produce it,
no one can confirm or deny their conclusions. The registry fails on the fundamental basis of scientific study—and
the fundamental basis of admissibility
under Daubert—so the defense experts’
opinions should be inadmissible.
In one recent case, a court struck a
defense expert associated with the POVL
registry for failing to produce the original source data so that it could be examined by the plaintiff’s experts.18 Defense
experts who rely on the registry to defeat
a patient’s cause of action should always
be challenged for this reason.
The factors that combine to cause
postoperative visual loss are known. Prudent anesthesiologists obtain informed
consent and are meticulous about maintaining proper blood flow, oxygenation,
and positioning during the surgery to
prevent this devastating outcome. When
an anesthesiologist ignores these duties
and blinds the patient, we can be there
to help.
James E. Girards is founder
of the Girards Law Firm in Dallas.
James W. Gustafson Jr. practices law
with Searcy, Denney, Scarola, Barnhart
& Shipley in Tallahassee, Florida.
Notes
1. See Elizabeth Lynne Williams,
Postoperative Blindness, 20 Anesthesiology Clinics
N. Am. 605 (2002).
2. See David M. Katz et al., Ischemic Optic
Neuropathy after Lumbar Spine Surgery,
112 Archives Ophthalmology 925 (1994).
3. See Mizra N. Baig et al., Vision Loss after
Spine Surgery: Review of the Literature and
Recommendations, 23 Neurosurgical Focus
15, 17 (2007); Lorri A. Lee & Arthur M.
Lam, Unilateral Blindness after Prone
Lumbar Spine Surgery, 95 Anesthesiology
793, 793 (2001).
