West Virginia Code of State Rules › Agency 85 - Workers' Compensation › Title 85 - PROCEDURAL RULE WORKERS' COMPENSATION RULES OF THE WEST VIRGINIA INSURANCE COMMISSIONER › Series 85-20 - Medical Management Of Claims, Guidelines For Impairment Evaluations, Evidence, And Ratings, And Ranges Of Permanent Partial Disability Awards › Section 85-20-52 - Procedure in Occupational Pneumoconiosis Cases

Current through Register Vol. XLI, No. 28, July 12, 2024
52.1. A properly completed application must
				be received before the potential claim will be considered by the Commission,
				Insurance Commissioner, private carrier or self-insured employer, whichever is
				applicable. A properly completed application must include 1) a completed WC-105
				form; 2) a completed WC-205 form; 3) an ILO form properly completed by a
				certified "B" reader; and 4) a listing of all alleged exposures to harmful
				dust, including type of dust, and extent and duration of exposure with each
				named employer.
52.2. If the
				employer submits credible evidence demonstrating that it has been in compliance
				with OSHA and/or MSHA permissible exposure levels, as determined by sampling
				and testing performed in compliance with OSHA and/or MSHA regulations for the
				dust alleged by the injured worker, then the Commission, Insurance
				Commissioner, private carrier or self-insured employer, whichever is
				applicable, may consider that the dust exposure alleged by the injured worker
				does not suffice to satisfy the exposure requirements of W. Va. Code
				§§
									23-4-1(b)
				and
				23-4-15(b)
				only for the period(s) covered by the sampling or testing. In order for the
				evidence to be deemed credible, it must be based upon regularly scheduled
				exposure samples from each work area where harmful exposure has been alleged,
				which samples will be obtained by certified industrial hygienists as defined by
				OSHA and/or MSHA regulations or government agencies, and the samplings must be
				obtained during the period for which the employer is seeking to avoid
				chargeability. The employer shall provide to all parties to the claim all
				discoverable communications to and from the industrial hygienist, and the
				entire test file, including the results of the industrial hygienist. In the
				absence of other relevant evidence, periods for which injured workers can
				demonstrate by credible evidence that the employer's sampling and test results
				do not accurately reflect conditions in the injured worker's work areas shall
				be included by the Commission, Insurance Commissioner, private carrier or
				self-insured employer, whichever is applicable, for the period of dust exposure
				which the claimant has alleged to be harmful.
52.3. Nonmedical hearing.
Upon receipt of a proper application, employer's reports and
				  investigation (if requested by the Commission or Insurance Commissioner,
				  whichever is applicable), the Commission or Insurance Commissioner, whichever
				  is applicable, shall determine the nonmedical questions, and shall notify all
				  interested parties of the decision; Provided, in cases where a self-insured
				  employer or private carrier is not requesting allocation, the self-insured
				  employer or private carrier shall enter the nonmedical order. A properly
				  completed application must be filed or the application shall be rejected. --
				  After the Commission, Insurance Commissioner, self-insured employer or private
				  carrier, whichever is applicable, makes or has made a determination, any
				  dissatisfied party may, within thirty (30) days after receipt of written notice
				  of the Commission's, Insurance Commissioner's, self-insured employer's or
				  private carrier's, whichever is applicable, decision, file objection thereto in
				  writing, whereupon the Office of Judges will set a time and place for a hearing
				  thereon. These hearings shall be subject to the provisions of the rules
				  promulgated by the Office of Judges (Title 93, Series 1).
Upon completion of the nonmedical hearing, the Office of
				  Judges will enter a final nonmedical ruling and shall notify the injured worker
				  and employer of this decision. The Office of Judge's final nonmedical ruling
				  will be subject to appeal to the Workers' Compensation Board of Review.
52.4. Occupational pneumoconiosis
				board hearing.
Following issuance by the Commission or Insurance
				  Commissioner, whichever is applicable, of a ruling on the nonmedical issues,
				  the Commission, Insurance Commissioner, private carrier or self-insured
				  employer, whichever is applicable, shall refer this claim to the Occupational
				  Pneumoconiosis Board: Provided That, the requirements of W. Va. Code §
									23-4-15b
				  have been satisfied. In the case of such reference, the Commission, Insurance
				  Commissioner, private carrier or self-insured employer, whichever is
				  applicable, will notify the injured worker to appear before the Board for an
				  examination and shall state the date, time, and location thereof. The
				  Commission, Insurance Commissioner, private carrier or self-insured employer,
				  whichever is applicable, will notify the employer or employers of the date,
				  time and place of the examination. A quorum of the Board will then proceed to
				  hear and determine all medical questions relating to the claim.
At such hearing the injured worker and each employer must
				  produce as evidence all reports of medical and X ray examinations that may be
				  in their respective possession or control showing the past or present condition
				  of the employee.
52.5. Report of
				Occupational Pneumoconiosis Board.
Upon completion of the hearing the participating members of
				  the Occupational Pneumoconiosis Board shall prepare a written report to the
				  Commission, Insurance Commissioner, private carrier or self-insured employer,
				  whichever is applicable, setting forth their findings and decision, and shall
				  prepare a sufficient number of signed copies of report so that the Commission,
				  Insurance Commissioner, private carrier or self-insured employer, whichever is
				  applicable, may file one in his office, send one to the injured worker and one
				  to each employer interested in the claim.
52.6. Objections.
Any interested party who objects, in whole or in part, to
				  the findings and conclusions of the Board may, within the statutory period
				  after the mailing to him of the copy of the report, or within such additional
				  time as may be allowed by the Commission, Insurance Commissioner, private
				  carrier or self-insured employer, whichever is applicable, for good cause
				  shown, file with the office of judges his written objections, specifying the
				  particular statements of the Board's findings and conclusions to which the
				  party objects. Upon receipt of such objection, the office of judges shall set a
				  time and place for a hearing thereon and shall notify each interested party and
				  each member of the Board of the time and place of the hearing.
52.7. Hearings on protest.
Hearings held upon protest to the findings of the
				  Occupational Pneumoconiosis Board will be held by the office of judges in
				  Charleston unless the office of judges shall otherwise direct. The procedure in
				  protest hearings shall be governed by the provisions of the procedural rules of
				  the office of judges, except that evidence shall be limited to medical
				  testimony and other competent medical evidence, unless the Board has passed
				  upon non-medical aspects under the Commission's or Insurance Commissioner's,
				  whichever is applicable, referral. Cross-examination of the Board shall be
				  limited to those members who examined the injured worker. However, if the
				  office of judges decides that testimony of other members of the Board is
				  necessary or desirable, the office of judges may permit such testimony at the
				  protest hearing.
52.8.
				Employer's Request For Medical Examination.
An employer's request for medical examination of the injured
				  worker by a physician of its choice, shall be rejected if filed before the
				  findings of the Occupational Pneumoconiosis Board have been transmitted to the
				  injured worker and the employer. Such requests shall be entertained only when
				  filed subsequent to the transmittal of the Occupational Pneumoconiosis Board
				  findings.
52.9. Standards
				for medical examination.
a. The following
				standards specify examination and evaluation criteria to guide the Occupational
				Pneumoconiosis Board in its examination and evaluation of injured workers, and
				to guide other physicians and medical technicians who conduct examinations and
				evaluations of injured workers on behalf of such injured workers and their
				employers. These standards are established for the further purpose of ensuring
				that uniform procedures are used in administering and interpreting ventilatory
				function tests and arterial blood gas studies and that the best available
				medical evidence will be obtained in support of a claim for occupational
				pneumoconiosis benefits. The physician supervising any such testing and/or the
				technician administering any such testing will so indicate by signing the
				reports. Any report of test results submitted to the Occupational
				Pneumoconiosis Board must affirmatively state, as to each of the standards
				individually, the fact that the particular test or study was performed in
				compliance with that standard. In the event that any such report fails to
				affirmatively show compliance with these standards, the Occupational
				Pneumoconiosis Board may disregard all or any part of such test or study or
				give such test or study such weight as the Board believes it
				deserves.
b. When two (2) or more
				ventilatory function tests performed in reasonably close proximity in time
				produce differing but acceptable results, the Commission or Insurance
				Commissioner, whichever is applicable, at the request of the Occupational
				Pneumoconiosis Board, may direct the parties to furnish additional evidence
				and/or order additional testing at the laboratory utilized by the Occupational
				Pneumoconiosis Board or other laboratories, all for the purpose of determining
				whether any of the results are unreliable or incorrect or are clearly
				attributable to some identifiable disease or illness other than occupational
				pneumoconiosis.
c. When blood gas
				studies are performed and abnormal values are obtained and thereafter new blood
				gas studies are performed and normal or significantly higher values are further
				obtained, the Commission or Insurance commissioner, whichever is applicable, at
				the request of the Occupational Pneumoconiosis Board, may direct the parties to
				furnish additional evidence and/or order additional studies at the laboratory
				utilized by the Occupational Pneumoconiosis Board or other laboratories, all
				for the purpose of determining whether any of the values are unreliable or
				incorrect or are clearly attributable to some identifiable disease or illness
				other than occupational pneumoconiosis.
d. As used herein, the following terms shall
				have the meanings indicated:
1. FVC -forced
				vital capacity -- Volume of air that can be forcefully exhaled from the lungs
				after a maximal inspiration.
2.
				FEV1 -forced expiratory volume in one (1) second --
				Volume of air that can be exhaled forcefully from the lungs in one (1) second
				after a maximal inspiration.
3..
				FEV3 -forced expiratory volume in three seconds --
				Volume of air that can be exhaled forcefully from the lungs in three (3)
				seconds after a maximal inspiration.
4. FEV1FEV -forced
				expiratory volume (timed) to forced expiratory volume. -- A ratio expressed as
				a percentage.
5. MVV -maximal
				voluntary ventilation -- The volume of air that can be exchanged over a unit
				period of time, usually performed for twelve (12) to fifteen (15) seconds and
				converted to liters per minute.
6.
				BTPS -- Body temperature, ambient pressure, saturated with water.
7. Kpm -kilopond meter -- The amount of work
				required to lift one (1) kilogram one (1) meter.
8. NIOSH -- National Institute for
				Occupational Safety and Health.
9.
				BOARD -- West Virginia Occupational Pneumoconiosis Board.
10. NBRC - National Board for Respiratory
				Care
11. CPFT - Certified Pulmonary
				Function Technician
12. RPFT --
				registered Pulmonary Function technologist
13. Raw - Airway resistance
14. DLCO - Carbon monoxide diffusing capacity
				of the lungs
15. DL/VA - Carbon
				monoxide diffusing capacity per unit of alveolar volume
16. VA - Alveolar volume (single breath
				equivalent to TLC)
17. TLC - Total
				Lung Capacity (measured by plethysmograph, Nitrogen washout, or helium
				dilution.
e. Ventilatory
				function tests.
1. Instruments to be used for
				the administration of ventilatory function tests should conform to the
				following criteria:
A. The instrument must be
				accurate within plus (+) fifty (50) ml or within plus (+) three percent (3%) of
				reading, whichever is greater.
B.
				The instrument must be capable of measuring vital capacity from zero (0) to
				seven (7) liters BTPS.
C. The
				instrument must have a low inertia and offer low resistance to airflow such
				that the resistance to airflow at twelve (12) liters per second must be less
				than 1.5 cm H20/liter/second.
D. The zero time point for the purpose of
				timing the FEV1 must be determined by extrapolating the
				steepest portion of volume-time curve back to the maximal inspiration volume or
				by an equivalent method.
E.
				Instruments incorporating measurements of airflow to determine volume must
				conform to the same volume accuracy stated in Subdivision 52.9.e.1.A of this
				regulation when present with flow rates from at least zero (0) to twelve (12)
				liters per second.
F. The
				instrument or user of the instrument must correct volumes to body temperature
				saturated with water vapor (BTPS) under conditions of varying ambient
				spirometer temperatures and barometric pressures.
G. The instrument used must provide tracings
				of volume versus time during the entire forced expiration. Flow versus volume
				tracings may be added. If MVV maneuver is performed, the volume versus time
				tracings must also be provided. Such tracing must be furnished to the Board
				with the test results. Volume Scale: When a volume - time curve is plotted or
				displayed, the volume scale must be at least: 10 mm/L (BTPS). Time scale: at
				least 10 mm/S. No results will be considered by the Board unless they are
				accompanied by the corresponding (minimum 3) tracings. Tracings are to
				determine whether the subject has performed the test properly. The tracing must
				be of sufficient size that hand measurements may be made within the requirement
				of paragraph 1A above.
H. The
				instrument must be capable of accumulating volume for a minimum of ten (10)
				seconds after the onset of exhalation.
I. The forced expiratory volume in one (1)
				second (FEV1 measurement must comply with the accuracy
				requirements stated in Subdivision 52.9.e.1 of these Regulations; that is, the
				FEV1 must be accurately measured to within plus (+)
				fifty (50) ml or within plus (+) three percent (3%) of reading, whichever is
				greater.
J. The instrument must be
				capable of being calibrated in the field with respect to the FVC and time
				scales. This calibration of the FVC may be done either directly or indirectly
				through volume and time base measurements. The volume calibration source must
				provide a volume displacement of at least three (3) liters and must be accurate
				to within plus (+) thirty (30) ml.
K. For measuring maximum voluntary
				ventilation (MVV), the instrument must have a response which is flat within
				plus (+) ten percent (10%) at flow rates up to twelve (12) liters per second
				over the volume range. The time for exhaled volume integration or recording
				must be no less than twelve (12) seconds and no more than fifteen (15) seconds.
				The indicated time must be accurate to within plus (+) three percent (3%). A
				recording of the spirometer tracing is required, and the volume sensitivity
				must be such than ten (10) mm or more deflection corresponds to one (1) liter
				volume.
2. The
				administration of ventilatory function tests must conform to the following
				criteria: For ascertainment of the FEV1 and FVC, a nose
				clip or alternative must be used. The procedures must be explained in simple
				terms to the subject who shall be instructed to loosen any tight clothing and
				sit or stand in front of the apparatus. Although the subject may sit or stand,
				care should be taken on repeat testing that the same position is used. Sitting
				position will be considered the preferred method although standing may be
				utilized for obese patients and notations made as to the position. Particular
				attention must be given to insure that the subject's chin is slightly elevated
				with the neck slightly extended. The subject must be instructed to make a full
				inspiration, either from the spirometer or the open atmosphere, and then blow
				into the apparatus, without interruption, as hard, fast, and completely as
				possible.
At least three (3) forced expirations must be carried out.
				  During the maneuvers, the subject must be observed for compliance with
				  instructions. The expirations must be checked visually for reproducibility by
				  examining the flow-volume or volume-time tracings. The effort shall be judged
				  unacceptable and cannot be considered in evaluating pulmonary functional
				  impairment when the subject:
A. The
				largest and second largest FVC are not within 7% of each other; or
B. The largest and second largest
				FEV1 are not within 7% of each other; or
C. Has not continued the expiration for at
				least six (6) seconds or until an obvious plateau in the volume-time curve has
				occurred. Exceptions: Young adults and patients with restrictive defects tend
				to plateau early. Reduced FVC with a normal or high
				FEV1/FVC ration is suggestive of restriction, although
				measurement of TLC is required to confirm restriction; or
D. Tracings indicate cough prior to the
				FEV1 measurement; or
E. Early termination of flow (glottis
				closure); or
F. Has an
				unsatisfactory start of expiration, one characterized by excessive hesitation
				(or false starts), and therefore did not allow back extrapolation of time zero
				(0) (extrapolated volume on the volume-time tracing must be less than ten
				percent (10%) of the FVC); or
G.
				Has an excessive variability between the three (3) acceptable curves. The
				variation between the two (2) largest FVCs and the two (2) largest
				FEV1s.
H.
				Predicted values are derived from Kory's Nomogram (1961).
3. For ascertainment of the MVV, the subject
				must be instructed before beginning the test that he or she will be asked to
				breathe as deeply and as rapidly as possible for approximately twelve (12)
				seconds. Sitting position will be considered the preferred method although
				standing may be utilized for obese patients and notations made as to the
				position. Care shall be taken on repeated testing that the same position is
				used. The test may be performed with the subject in either a sitting or
				standing position. Care shall be taken on repeat testing that the same position
				is used. The subject should breathe normally into the mouthpiece of the
				apparatus for ten (10) to fifteen (15) seconds to become accustomed to the
				system. The subject should then be instructed to breathe as deeply and as
				rapidly as possible and shall be continually encouraged during the remainder of
				the maneuver. The subject shall continue the maneuver for twelve (12) seconds.
				Only one (1) MVV maneuver is necessary. The effort must be judged unacceptable
				and cannot be considered in evaluating pulmonary functional impairment when the
				patient:
A. Has not maintained consistent
				effort for at least twelve (12) to fifteen (15) seconds; or
B. Has coughed or closed his glottis;
				or
C. Has an obstructed mouthpiece
				or a leak around the mouthpiece (obstruction due to tongue being placed in
				front of mouthpiece, false teeth falling in front of mouthpiece, etc.);
				or
D. Has an excessive variability
				between the three (3) satisfactory curves. The variation between the three (3)
				satisfactory tracings must not exceed ten percent (10%) and should approximate
				forty (40) times the greatest FEV1 volume.
4. A calibration check must be
				performed on the instrument each day before use, using a volume source of at
				least three (3) liters, accurate to within +one percent (1%) of full scale. The
				room air in the syringe must be introduced into the spirometer once with a flow
				rate of approximately five tenths (5/10) liters per second (six (6) seconds
				emptying time with a three (3) liter syringe) and once with a higher flow rate
				of approximately three (3) liters per second (one (1) second emptying time with
				a three (3) liter syringe). The volume measured by the spirometer must be
				between two and nine tenths (2.90) and three and one tenth (3.10) liters for
				both trials. Accuracy of the time measurement used in determining the
				FEV1 must be checked using the manufacturer's stated
				procedure and must be within +three percent (3%) of actual. The procedure
				described herein must be performed as well as any other procedures suggested by
				the manufacturer of the spirometer being used.
5. The first step in evaluating a spirogram
				for the FVC and FEV1 shall be to determine whether or
				not the subject has performed the test properly or as described in Subdivision
				52.9.e.2 of this regulation and the forced expiratory volume. From the three
				(3) satisfactory tracings, the forced vital capacity (FVC) and the forced
				expiratory volume in one (1) second (FEV1) must be
				measured and recorded. The largest FVC and the largest
				FEV1 must be used in the analysis, corrected to
				BTPS.
6. Only MVV maneuvers which
				demonstrate consistent effort for at least twelve (12) seconds shall be
				considered acceptable. The largest accumulated volume for a twelve (12) second
				period corrected to BTPS and multiplied by five (5) shall be reported as the
				MVV.
f. Single Breath
				Carbon Monoxide Diffusion Capacity
1. For
				ascertainment of the Single Breath DLCO, the subject must be instructed before
				beginning the test that he or she will be asked to breath normally through the
				system for a number of breaths to achieve stable tidal breathing, then exhale
				to the level of residual volume (RV). At that point, the patient will be
				instructed to inhale quickly to the level of Total Lung Capacity (TLC) and hold
				their breath for approximately 10 seconds, then exhale for sample collection in
				the instruction of the technician administering the test.
2. Single breath carbon monoxide diffusion
				capacity tests are performed using the Jones-Meade method of
				measurement.
3. Predicted values
				are derived from Crapo (1981) nomogram.
4. Total Hemoglobin and Carboxyhemoglobin are
				to be reported. Subjects with anemia will have results corrected to hemoglobin
				of 14.6 (males) and 13.4 (females).
5. IVCs from each acceptable maneuver shall
				be reported.
6. Reports will
				include DLCO, Alveolar Volume (VA) and DL/VA.
7. At least two (2) maneuvers are to be
				carried out. During the maneuvers, the subject must be observed for compliance
				of instructions. The effort(s) shall be judged unacceptable and cannot be
				considered in evaluating pulmonary function impairment when the subject:
A. IVCs do not achieve 85% of previously
				measured vital capacity.
B. Actual
				DLCO measurements are not within 3 ml or 10% whichever is larger.
C. IVCx (SVCs) are not reported for each
				acceptable maneuver.
D. Inspiratory
				time exceeds 2.5 seconds.
E. Breath
				hold time is less than 9 seconds or exceeds 11 seconds.
F. Sample is not obtained within 4 seconds
				after breath hold.
G.
				Carboxyhemoglobin is not reported or value is 3.1% or higher.
g. AIRWAY RESISTANCE
				(Raw)
1. Airway resistance measurement will
				be measured using a body plethysmograph. For ascertainment of the Raw, the
				subject must be instructed before beginning the test that he or she will, after
				being sealed in the plethysmograph, be asked to breath normally while
				temperature equilibration occurs and then to hold cheeks with hands and gently
				pant while open and close shutter measurements are taken.
h. Arterial blood gas studies.
1. In order to ensure comparability of data
				obtained in arterial blood studies, the following guidelines should be
				observed:
A. The puncture site should be
				infiltrated with a local anesthetic to minimize pain and arterial
				spasm.
B. The barrel of the syringe
				used to draw the blood sample should contain a coating of lithium heparin. If
				wetted syringes are used, the excess heparin must be expelled just prior to
				obtaining the blood sample.
C. The
				subject should be allowed to rest while breathing room air for fifteen (15)
				minutes prior to drawing the sample.
D. Resting blood samples should be drawn with
				the subject in the sitting position. If supine position is necessary, a
				notation is to be made on the report.
E. On occasions when the subject is unable to
				be exercised due to physical impairments; i.e., heart disease, artificial leg,
				etc., a resting sample of arterial blood may be drawn by direct puncture with a
				twenty-twenty-five (20-25) gauge needle and a heparinized syringe.
F. Blood samples must be discarded if
				contaminated by an air bubble.
G.
				All blood samples should be analyzed immediately (less than ten (10) minutes).
				If not, the sample should be placed in ice water slush for up to 1 hour. If the
				analysis is not performed within ten (10) minutes, the metabolic activity of
				the cells in the blood will cause the p02 to fall and
				the pC02 to rise.
H. If an exercise sample is to be obtained, a
				plastic catheter may be inserted into the radial or brachial artery for both
				the resting as well as the exercise sample. Single stick exercise samples may
				also be obtained if drawn during the last 30 seconds of exercise. Any variation
				should be so noted.
I. Exercise
				must be accomplished by having the subject pedal the bicycle ergometer at a
				rate of fifty (50)-sixty (60) revolutions per minute against a resistance of
				seventy-five (75) Watts or four hundred fifty (450) Kilopond Meters (Kpm) per
				minute for a period of five (5) minutes. A treadmill may be used, and when
				used, exercise must be done at two (2) mph and ten percent (10%) grade. During
				the last twenty (20) seconds of the fifth minute of exercise, the exercise
				sample must be drawn into a heparinized syringe and the pulse and respiration
				rates noted. If an added level of exercise is performed, this must be done at
				one hundred twenty (120) Watts on the bicycle, or on the treadmill at two and
				five tenths (2 5/10) mph and twelve percent (12%) grade. Exercise testing
				beyond the level set forth herein shall be considered to be measurements of
				physical conditioning rather than of blood gas transfer abnormalities due to
				occupational pneumoconiosis. The EKG leads are then removed and the subject
				allowed to sit on a chair while the catheter is removed. Pressure must be held
				at the site of arterial cannulation for five (5) minutes, and if there is no
				bleeding or hematoma present, a compression bandage must be placed on the
				radial artery. This bandage must be left in place for four (4) hours. After
				about fifteen (15) minutes of observation, the subject will be allowed to
				leave. The arterial blood sample should be drawn while exercise continues, not
				following cessation of exercise.
J.
				EKG monitoring with a single lead should take place during exercise to
				determine the heart rate. It should be noted that this is not an EKG Stress
				Test.
K. The report should indicate
				the place, date and time of the study, altitude of the testing site and
				barometric pressure at the testing site on the day of the testing, name and
				claim number of the subject, name of any assisting personnel, name and
				signature of the supervising physician, duration and type of exercise (if
				performed), pulse rate and respiration at the time the blood sample was drawn,
				and whether analysis equipment was calibrated before each test.
2. It is recognized that arterial
				blood gas studies done in laboratories throughout this state are obtained at
				different altitudes. Only by "Standardizing" for altitude can an equitable
				assessment be made of impairment when values of arterial oxygen are being
				measured at remarkably different altitudes. Therefore, the results reported
				from laboratories should include the name of the laboratory and the date and
				time of the testing, altitude of the laboratory and barometric pressure at the
				laboratory on the day the samples were collected. The Occupational
				Pneumoconiosis Board will evaluate the arterial blood gas values by converting
				those values to the average altitude of Charleston, West Virginia. For this
				purpose, it shall be sufficient to add one (1) mmHg to each arterial oxygen
				tension for each three hundred (300) feet or fraction thereof that the testing
				laboratory is located above the average altitude of Charleston, because the
				relationship of barometric pressure (altitude) and alveolar oxygen is
				approximately linear up to four thousand (4,000) feet as long as the subject
				breathes room air.
As an example, Bluefield is located approximately two
				  thousand six hundred (2,600) feet above sea level. Charleston is approximately
				  six hundred (600) feet above sea level. Thus, arterial oxygen values obtained
				  in Bluefield should have 6.67 mmHg added to them before applying the table to
				  them to obtain "percent impairment". The calculations are as follows:
"Bluefield (2,600') minus Charleston (600') equals 2,000'
				  differential
2,000' divided by 300' altitude equals 6.67 multiplied by 1
				  mmHg per 300' altitude equals 6.67 mmHg"
i. See the attached Table 85-20A, "Impairment
				of Pulmonary Function."