United States District Court, D. Minnesota
N. ERICKSEN UNITED STATES DISTRICT JUDGE.
above-captioned case is a member case in the MDL in re
Bair Hugger Forced Air Warming Devices Products
Liability Litigation, 15-md-2666. It is scheduled to be
the first member case tried. On May 4, 2018, the Court heard
oral argument on the parties' Motions to exclude
evidence. The Court decided some of those Motions on the
record. The Court now decides the rest.
Defendants' Motion  to exclude evidence about
bacteria in the Bair Hugger system's filter or on its
Plaintiffs advance two theories of causation. One is that the
operation of the Bair Hugger disrupts operating room airflow
and causes ambient bacteria to be deposited into the surgical
site or onto the prosthetic joint. This theory will be tested
at trial. A second theory of causation is that the Bair
Hugger itself harbors bacteria, and that these bacteria
escape the warming unit during surgery. Defendants have moved
to exclude from the Gareis trial evidence pertaining
only to this second theory. For the following reasons that
motion is granted.
Gareis's infection was caused by Staphylococcus
epidermidis, bacteria that are “common organisms
found on the skin of humans, ” Jarvis Rpt. 4, Dkt. No.
253-1, humans including the patient and operating room
personnel. See also Avidan et al., Convection
warmers - not just hot air, 52 Anaesthesia 1073 (1997)
(describing Staphylococcus epidermidis as
“typical of skin flora”), cited in
Jarvis Rpt. 9. Humans shed skin flakes, also known as
squames. According even to Plaintiffs' expert Dr. Said
Elghobashi, “for the five persons (four medical staff
and the patient) in the [operating room] a realistic number
would be about 105 million squames per hour.”
Elghobashi Rpt. 12, Dkt. No. 106-5. So, this shedding would
carry many colony-forming units of Staphylococcus
epidermidis. Plaintiffs have no evidence that however
many Staphylococcus epidermidis might be in the Bair
Hugger, that that number would have a meaningful impact on
the bacterial load of that pathogen in the operating room.
Bair Hugger, of course, does not sit passively during an
operation. It blows air out of small holes in its blanket.
The blanket is not placed directly onto or near the
prosthetic joint, however, and so even if Staphylococcus
epidermidis were to escape the blanket, it would not be
deposited directly onto the prosthetic joint or into the
surgical site. More importantly for purposes of disposing of
the current motion, however, Plaintiffs have no evidence that
anyone has caught colony-forming units of bacteria floating
out of the blanket's perforations. There is
empirical evidence that particles, especially small particles
(less than 5 microns, Buck Rpt. 16, MDL Dkt. No. 315-2), can
escape the perforations. But see Elghobashi Rpt. 2
(“The squame particle size ranges over 4-20 µm of
equivalent diameter.” (citation omitted)), Dkt. No.
106-1. Plaintiffs maintain that particles stand in as a proxy
for bacteria. See Gregory W. Stocks, et al.,
Predicting bacterial populations based on airborne
particulates: a study performed in nonlaminar flow operating
rooms during joint arthroplasty surgery, 38 Am. J.
Infect. Control 199 (2010) (analyzing operating room air
during surgery and finding correlation between 10-µm
particles and colony-forming units), cited in Jarvis
so, but no expert brought to the Court's attention has
tested the air coming out of a Bair Hugger's blanket and
discovered escaping colony-forming units. This test would be
feasible; it is certainly not cutting-edge. Stocks et al. 200
(measuring “airborne viable bacteria . . . using an
impact sampler”); see Polski v. Quigley Corp.,
538 F.3d 836, 840 (8th Cir. 2008) (emphasizing lack of
testing, when affirming exclusion under Fed.R.Evid. 702,
because “theory could have easily . . . been
tested”). Given the resources Plaintiffs have spent on
generating expert testimony for this case, this test's
absence is curious. Instead, scientists relied on by the
Plaintiffs have cultured air from the Bair Hugger's
internal hose. They have examined Bair Huggers in operation.
They have not, however, shown any pathogen coming out of the
“business end” of the Bair Hugger-the perforated
blanket. No. examination was conducted of the Bair Hugger
that was used in the surgery Mr. Gareis claims caused his
proponents of this evidence, Plaintiffs have failed to meet
their burden. The evidence's relevance “depends on
whether a fact exists”: that is, whether colony-forming
units escape the Bair Hugger's perforated blanket.
See Fed. R. Evid. 104(b). Plaintiffs have not, as
they must, introduced sufficient proof “to support a
finding that the fact does exist.” Id.
even if they did so, Plaintiffs' own experts report facts
that show that second theory would involve “undue
delay.” See Fed. R. Evid. 403. Even if the
Bair Hugger adds an apparently undetectable amount of
Staphylococcus epidermidis to the operating room,
that marginal addition would be swamped by the
Staphylococcus epidermidis that Plaintiffs'
experts report is already there. As has already been noted,
Plaintiffs proffer no evidence to the contrary. For evidence
supporting only the second causation theory, that
evidence's “probative value is substantially
outweighed by a danger of . . . undue delay.”
Gareis's Motion [Dkt. No. 214] to exclude evidence about
seek exclusion of Defendants' expert testimony as to
alternative causes. Those experts, including Dr. Michael
Mont, opine, among other opinions, that many things disrupt
or heat operating room airflow and that surgical records
imperfectly reflect what happened before, during or after
Motion is DENIED because Mont's testimony is based on
sufficient facts and Defendants other experts may rely on
Mont. See Hill v. Sw. Energy Co., 858 F.3d 481, 486
(8th Cir. 2017) (reversing exclusion because, though
untrained in geology, engineer could apply his methods to
data geologist derived); Hartley v. Dillard's,
Inc., 310 F.3d 1054, 1061 (8th Cir. 2002) (“Only
if the expert's opinion is so fundamentally unsupported
that it can offer no assistance to the jury must such
testimony be excluded.”). Mont bases his opinion on
scientific Publications, his experience as an orthopedic
surgeon, and the depositions of Mr. Gareis's treating
disruption or heating of operating room airflow,
Defendants' expert Michael Mont lists operating room
features that generate heat and airflow comparable to what a
Bair Hugger system would do. Mont Gen. Rpt. 9-11, MDL Dkt.
798-10. He can list these features based on his experience as
a surgeon who has done “joint replacement surgeries . .
. a total of over 15, 000 since 1990.” Id. at
surgical records, Mont testifies only that these records are
imperfect-not that any particular unrecorded event is likely.
Mont Spec. Rpt. 11 (“During surgical procedures,
numerous unexpected events occur which could lead to
infection, but those frequently are not documented.”),
Dkt. No. 55-1 (Ex. 5). As a surgeon, he is familiar with
medical records generated before, during ...