436-035-0385 Respiratory System (1) For the purpose of this rule, the following definitions apply: (a) FVC is forced vital capacity. (b) FEV1 is forced expiratory volume in the first second. (c) Dco refers to diffusing capacity of carbon monoxide. (d) VO2 Max is measured exercise capacity. (2) Lung impairment is rated according to the following classes: (a) Class 1: 0% for FVC greater than or equal to 80% of predicted, and FEV1 greater than or equal to 80% of predicted, and FEV1/FVC greater than or equal to 70%, and Dco greater than or equal to 80% of predicted; or VO2 Max greater than 25 ml/(kg x min). (b) Class 2: 18% for FVC between 60% and 79% of predicted, or FEV1 between 60% and 79% of predicted, or FEV1/FVC between 60% and 69%, or Dco between 60% and 79% of predicted, or VO2 Max greater than or equal to 20 ml/(kg x min) and less than or equal to 25 ml/(kg x min). (c) Class 3: 38% for FVC between 51% and 59% of predicted, or FEV1 between 41% and 59% of predicted, or FEV1/FVC between 41% and 59%, or Dco between 41% and 59% of predicted, or VO2 Max greater than or equal to 15 ml/(kg x min) and less than 20 ml/(kg x min). (d) Class 4: 75% for FVC less than or equal to 50% of predicted, or FEV1 less than or equal to 40% of predicted, or FEV1/FVC less than or equal to 40%, or Dco less than or equal to 40% of predicted, or VO2 Max less than 15 ml/(kg x min). (3) Lung cancer - All persons with lung cancers as a result of a compensable industrial injury or occupational disease are to be considered Class 4 impaired at the time of diagnosis. At a re-evaluation, one year after the diagnosis is established, if the person is found to be free of all evidence of tumor, then the person should be rated under the physiologic parameters in OAR 436-035-0385(2). If there is evidence of tumor, the person is determined to have Class 4 impairment. (4) Asthma - Reversible obstructive airway disease is rated under the classes of respiratory impairment described in section (2) of this rule. The impairment is based on the best of three successive tests performed at least one week apart at a time when the patient is receiving optimal medical therapy. In addition, a worker may also have impairment determined under OAR 436-035-0450. (5) Allergic respiratory responses - For workers who have developed an allergic respiratory response to physical, chemical, or biological agents refer to OAR 436-035-0450. Methacholine inhalation testing is permitted at the discretion of the physician. Where methacholine inhalation testing leaves the worker at risk, level of impairment may be based on review of the medical record. (6) Impairment from air passage defects is determined according to the following classes: [See attached class descriptions.] (7) Residual impairment from a lobectomy is valued based on the physiological parameters found under section (2) of this rule. (8) For injuries that result in impaired ability to speak, the following classes are used to rate the worker’s ability to speak in relation to: audibility (ability to speak loudly enough to be heard); intelligibility (ability to articulate well enough to be understood); and functional efficiency (ability to produce a serviceably fast rate of speech and to sustain it over a useful period of time). (a) Class 1: 4% when speech can be produced with sufficient intensity and articular quality to meet most of the needs of everyday speech communication; some hesitation or slowness of speech may exist; certain phonetic units may be difficult or impossible to produce; listeners may require the speaker to repeat. (b) Class 2: 9% when speech can be produced with sufficient intensity and articular quality to meet many of the needs of everyday speech communication; speech may be discontinuous, hesitant or slow; can be understood by a stranger but may have many inaccuracies; may have difficulty being heard in loud places. (c) Class 3: 18% when speech can be produced with sufficient intensity and articular quality to meet some of the needs of everyday speech communication; often consecutive speech can only be sustained for brief periods; can converse with family and friends but may not be understood by strangers; may often be asked to repeat; has difficulty being heard in loud places; voice tires rapidly and tends to become inaudible after a few seconds. (d) Class 4: 26% when speech can be produced with sufficient intensity and articular quality to meet few of the needs of everyday speech communication; consecutive speech limited to single words or short phrases; speech is labored and impractically slow; can produce some phonetic units but may use approximations that are unintelligible or out of context; may be able to whisper audibly but has no voice. (e) Class 5: 33% for complete inability to meet the needs of everyday speech communication. (9) Workers with successful permanent tracheostomy or stoma should be rated at 25% impairment of the respiratory system. [ED. NOTE: To view attachments referenced in rule text, click here to view rule.] Statutory/Other Authority: ORS 656.726 Statutes/Other Implemented: ORS 656.726, ORS 656.005, ORS 656.214 & ORS 656.268 History: WCD 8-2022, amend filed 11/08/2022, effective 12/04/2022 WCD 8-2012, f. 11-26-12, cert. ef. 1-1-13 WCD 9-2004, f. 10-26-04, cert. ef. 1-1-05 WCD 6-1992, f. 2-14-92, cert. ef. 3-13-92 WCD 2-1991, f. 3-26-91, cert. ef. 4-1-91 Reverted to WCD 7-1988, f. 12-21-88, cert. ef. 1-1-89 WCD 18-1990(Temp), f. 9-14-90, cert. ef. 10-1-90 WCD 7-1988, f. 12-21-88, cert. ef. 1-1-89 WCD 5-1988, f. 9-2-88, cert. ef. 8-19-88 WCD 2-1988, f. 6-3-88, cert. ef. 7-1-88