Table 5a. Case ascertainment: Criteria for reporting and case finding by data source and jurisdiction,
2009-2011
Data Source
PCC
FL
Medical
outcome=minor,
moderate, major
effect; death.
Hospital inpatient
ED
Syndromic where
chief
complaint=”carbon”
or “carbon
monoxide” or “CO”
ME
Call type =
exposure.
Substance=
carbon
monoxide
ICD9 codes:
986.0, E868.2,
E868.3, E868.8,
E868.9, E982.0,
E982.1 in
primary or
secondary
discharge
diagnosis field
ICD9 codes:
986.0, E868.2,
E868.3, E868.8,
E868.9, E982.0,
E982.1 in
primary or
secondary
discharge
diagnosis field.
Syndromic chief
complaint =
carbon
monoxide or CO.
Hospital
outpatient
Lab
carboxyhemogl
obin (COHb)
level
COHB≥9%
>= to 5%
Hyperbaric
Known or
suspected CO
Anyone who
received
MI
Call type=exposure.
Substance=carbon
monoxide.
Reason for
exposure=unintenti
onal.
Medical
outcome=minor,
moderate, major
effect; death.
ICD9 codes: 986.0,
E868.3, E868.8,
E868.9, and E982.1
in primary or
secondary diagnosis
field
MO
-
-
Medical records
with ICD9 codes:
986, E868.3, E868.8,
E868.9, and E982.1
in primary or any
secondary diagnosis
field
Syndromic where
chief
complaint=”carbon”
or “monoxide” or
“CO”, excluding
records when “CO”
means “complaint
of” or “county”
ICD9 codes: 986,
E868.3, E868.8,
E868.9, and E982.1
in primary or any
secondary diagnosis
field
COHB>10
-
-
All COHb tests
poisoning
hyperbaric
treatment for
carbon
monoxide
poisoning
Clinician
reporting
Known or suspected
CO poisoning
Reporting
requirements: All
cases with clinical
signs, symptoms
or known
exposure
consistent with a
diagnosis of
carbon monoxide
poisoning and/or
a
carboxyhemoglobi
n (COHb) level
equal to or above
5.0%
Death
certificate
ICD10: T58 as
underlying cause
ICD10: T58 as
underlying cause
or contributing
cause of death?
News reports
?
Google alerts:
(online, or
for carbon
“clipping
monoxide
service”)
exposure/poison
ing. Emergency
Medical Service
Reports: real
time reports of
carbon
monoxide
exposures.
“-“: Cases not identified from that source
Known or suspected
unintentional CO
poisoning
-
ICD10: T58 as
underlying cause
ICD10: X47,Y17,T58
underlying or
contributing cause
-
?
Table 5b. Case definitions for case classification, by jurisdiction
State Classification
FL
Confirmed
case*
Definition
1) A case with signs and symptoms consistent with acute CO poisoning and a
confirmed elevated COHb level (≥9%), as determined by either a blood
specimen (See laboratory criteria for diagnosis below) or pulse CO-oximetry or a
case with signs and symptoms consistent with acute CO poisoning (in absence of
clinical laboratory data), with supplementary evidence in the form of
environmental monitoring data suggesting exposure from a specific poisoning
source.
Probable
Case
Suspect Case
ME
Confirmed
case
Probable case
Suspect case
MI
Confirmed
case*
MO
Confirmed
case*
2) A case with a reported blood specimen (in the absence of clinical and
environmental laboratory data) with COHb level that is equal to or greater than
a volume fraction of 0.12 (12%).
1. A case with signs and symptoms consistent with acute CO poisoning and the
same environmental monitoring evidence of exposure with the same
environmental exposure as that of a confirmed case. (No laboratory and/or
environmental monitoring evidence of exposure present).
OR
2. A case with signs and symptoms consistent with acute CO poisoning and
history of environmental monitoring evidence of exposure with smoke
inhalation secondary to conflagration (explosive fire). (No laboratory and/or
environmental monitoring evidence of exposure present).
OR
3. A case with a reported blood specimen of COHb level that is equal or greater
than a volume fraction of 0.09 (9%) and less than a volume fraction of 0.12
(12%),(9%≤ COHb ≤ 12%) in the absence of compatible symptoms or
environmental monitoring data.
A case with signs and symptoms consistent with acute CO poisoning and a
history consistent with recent exposure to carbon monoxide.
T58 listed as underlying or contributing cause of death – or - COHb >=5.0% in
non-smokers - or - COHb >= 12.0% in smokers or when smoking status unknown
- or - Signs and/or symptoms consistent with CO poisoning accompanied by
evidence of an environmental exposure consistent with CO poisoning.
9.0%<= COHb <= 12.0% in smokers or when smoking status unknown – or –
Signs and/or symptoms consistent with acute CO poisoning and concurrent
environmental exposure as that of confirmed CO poisoning case – or -Loss of
consciousness or death without alternative explanation and exposure to source
of CO – or - Evidence of an environmental exposure consistent with CO
poisoning
COHb >= 12.0% as measured by pulse co-oximeter 1 or more non-specific
symptoms of CO poisoning and environmental monitoring consistent with CO in
the environment (e.g. CO detector) or documented exposure to a source of CO
*CoHb levels: unless there is a more plausible conflicting clinical explanation for
these results
1) A patient who was treated by a health care provider for health effects of
exposure to carbon monoxide, where the exposure was not intentional (i.e.
suicides with CO are excluded). Some evidence of an exposure source is
required (e.g., medical record noted CO alarm went off, malfunctioning furnace
fixed, patient was using gas powered equipment in enclosed space), but a
quantitative exposure of CO in air is not required.
2) A death where ICD10 code was T58 as underlying cause and “manner of
death” on the death certificate is not homicide or suicide.
1) A case meeting criteria for case finding using the case finding algorithm for
syndromic from EDs (see table 5a).
2) All cases with a laboratory report of a COHb level of 15% or higher.
3) All deaths with ICD-10 X47, Y17, T58 in the underlying or any contributing
cause field on death certificate, excluding intentional, fire-related, and
exposures to gases other than CO.
*Michigan, Florida and Missouri have a definition for a “confirmed” case, and do not classify cases using
the CSTE/CDC system of “confirmed”, “probable” and “suspect”. Final case counts do not include cases
classified as Suspect.