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The CPT® Code 94727 refers to a specialized pulmonary function test known as gas dilution or washout, which is utilized to determine lung volumes and, when applicable, assess the distribution of ventilation and closing volumes within the lungs. This procedure employs a spirometry device and involves the use of helium as a test gas. In the gas dilution method, a mixture of air enriched with 25-30 percent oxygen and approximately 10 percent helium is inhaled by the patient. The purpose of this test is to measure how well helium mixes with the gases in the lungs, which allows for the calculation of lung volume based on the known volume of inhaled gases and the fraction of helium present. To ensure accurate results, clips are placed on the patient's nose to prevent the entry of ambient air during the test. The patient breathes through a mouthpiece, initially receiving room air before transitioning to the test gas. Regular tidal breaths are taken, and the concentration of helium is monitored at 15-second intervals. The test concludes when the change in helium concentration is less than 0.02 percent for a duration of 30 seconds, at which point the patient is switched back to room air. The results, including helium concentration and tidal volume, are graphically displayed for analysis. In addition to gas dilution, the washout technique measures the amount of expired nitrogen (N2) over a specified time frame, which is critical for calculating the maximum lung capacity. The test begins with the establishment of an initial N2 alveolar concentration, followed by the patient breathing room air through the mouthpiece. The nitrogen washout is conducted by having the patient inhale 100 percent oxygen (O2), while the expired N2 concentration is continuously monitored. The washout is deemed complete when the N2 concentration falls below 1.5 percent for three consecutive breaths. Similar to the gas dilution method, the results of the nitrogen washout are graphically represented, and the physician is responsible for reviewing the findings and generating a written report. Throughout the procedure, the physician may also evaluate the distribution of gases within the lungs and assess closing volumes, providing a comprehensive understanding of the patient's pulmonary function.
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The gas dilution or washout procedure, represented by CPT® Code 94727, is indicated for various clinical scenarios where assessment of lung volumes and ventilation distribution is necessary. The following conditions may warrant the performance of this test:
The gas dilution or washout procedure involves several key steps to accurately measure lung volumes and assess ventilation. The following outlines the procedural steps:
After the completion of the gas dilution or washout procedure, the patient may be monitored briefly to ensure there are no immediate adverse reactions. The physician will review the test results, which include the calculated lung volumes and any observations regarding the distribution of ventilation and closing volumes. A written report summarizing the findings will be provided to the patient’s healthcare provider for further evaluation and management. Patients are typically advised to resume normal activities unless otherwise directed by their physician. Any specific post-procedure instructions or follow-up appointments will be communicated based on the individual patient's needs and the results of the test.
| Short Descr | PULM FUNCTION TEST BY GAS | Medium Descr | GAS DILUT/WASHOUT LUNG VOL W/WO DISTRIB VENT&V | Long Descr | Gas dilution or washout for determination of lung volumes and, when performed, distribution of ventilation and closing volumes | Status Code | Active Code | Global Days | XXX - Global Concept Does Not Apply | PC/TC Indicator (26, TC) | 1 - Diagnostic Tests for Radiology Services | Multiple Procedures (51) | 0 - No payment adjustment rules for multiple procedures apply. | Bilateral Surgery (50) | 0 - 150% payment adjustment for bilateral procedures does NOT apply. | Physician Supervisions | 09 - Concept does not apply. | Assistant Surgeon (80, 82) | 0 - Payment restriction for assistants at surgery applies to this procedure... | Co-Surgeons (62) | 0 - Co-surgeons not permitted for this procedure. | Team Surgery (66) | 0 - Team surgeons not permitted for this procedure. | Diagnostic Imaging Family | 99 - Concept Does Not Apply | APC Status Indicator | STV-Packaged Codes | Type of Service (TOS) | 5 - Diagnostic Laboratory | Berenson-Eggers TOS (BETOS) | T2D - Other tests - other | MUE | 1 | CCS Clinical Classification | 38 - Other diagnostic procedures on lung and bronchus |
This is a primary code that can be used with these additional add-on codes.
| 94729 | Addon Code MPFS Status: Active Code APC N Diffusing capacity (eg, carbon monoxide, membrane) (List separately in addition to code for primary procedure) |
| 26 | Professional component: certain procedures are a combination of a physician or other qualified health care professional component and a technical component. when the physician or other qualified health care professional component is reported separately, the service may be identified by adding modifier 26 to the usual procedure number. | 59 | Distinct procedural service: under certain circumstances, it may be necessary to indicate that a procedure or service was distinct or independent from other non-e/m services performed on the same day. modifier 59 is used to identify procedures/services, other than e/m services, that are not normally reported together, but are appropriate under the circumstances. documentation must support a different session, different procedure or surgery, different site or organ system, separate incision/excision, separate lesion, or separate injury (or area of injury in extensive injuries) not ordinarily encountered or performed on the same day by the same individual. however, when another already established modifier is appropriate it should be used rather than modifier 59. only if no more descriptive modifier is available, and the use of modifier 59 best explains the circumstances, should modifier 59 be used. note: modifier 59 should not be appended to an e/m service. to report a separate and distinct e/m service with a non-e/m service performed on the same date, see modifier 25. | TC | Technical component; under certain circumstances, a charge may be made for the technical component alone; under those circumstances the technical component charge is identified by adding modifier 'tc' to the usual procedure number; technical component charges are institutional charges and not billed separately by physicians; however, portable x-ray suppliers only bill for technical component and should utilize modifier tc; the charge data from portable x-ray suppliers will then be used to build customary and prevailing profiles | GZ | Item or service expected to be denied as not reasonable and necessary | XE | Separate encounter, a service that is distinct because it occurred during a separate encounter | XU | Unusual non-overlapping service, the use of a service that is distinct because it does not overlap usual components of the main service | CR | Catastrophe/disaster related | GC | This service has been performed in part by a resident under the direction of a teaching physician | 53 | Discontinued procedure: under certain circumstances, the physician or other qualified health care professional may elect to terminate a surgical or diagnostic procedure. due to extenuating circumstances or those that threaten the well being of the patient, it may be necessary to indicate that a surgical or diagnostic procedure was started but discontinued. this circumstance may be reported by adding modifier 53 to the code reported by the individual for the discontinued procedure. note: this modifier is not used to report the elective cancellation of a procedure prior to the patient's anesthesia induction and/or surgical preparation in the operating suite. for outpatient hospital/ambulatory surgery center (asc) reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | AQ | Physician providing a service in an unlisted health professional shortage area (hpsa) | GA | Waiver of liability statement issued as required by payer policy, individual case | Q6 | Service furnished under a fee-for-time compensation arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | GV | Attending physician not employed or paid under arrangement by the patient's hospice provider | 76 | Repeat procedure or service by same physician or other qualified health care professional: it may be necessary to indicate that a procedure or service was repeated by the same physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 76 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | GW | Service not related to the hospice patient's terminal condition | 25 | Significant, separately identifiable evaluation and management service by the same physician or other qualified health care professional on the same day of the procedure or other service: it may be necessary to indicate that on the day a procedure or service identified by a cpt code was performed, the patient's condition required a significant, separately identifiable e/m service above and beyond the other service provided or beyond the usual preoperative and postoperative care associated with the procedure that was performed. a significant, separately identifiable e/m service is defined or substantiated by documentation that satisfies the relevant criteria for the respective e/m service to be reported (see evaluation and management services guidelines for instructions on determining level of e/m service). the e/m service may be prompted by the symptom or condition for which the procedure and/or service was provided. as such, different diagnoses are not required for reporting of the e/m services on the same date. this circumstance may be reported by adding modifier 25 to the appropriate level of e/m service. note: this modifier is not used to report an e/m service that resulted in a decision to perform surgery. see modifier 57 for significant, separately identifiable non-e/m services, see modifier 59. | 27 | Multiple outpatient hospital e/m encounters on the same date: for hospital outpatient reporting purposes, utilization of hospital resources related to separate and distinct e/m encounters performed in multiple outpatient hospital settings on the same date may be reported by adding modifier 27 to each appropriate level outpatient and/or emergency department e/m code(s). this modifier provides a means of reporting circumstances involving evaluation and management services provided by physician(s) in more than one (multiple) outpatient hospital setting(s) (eg, hospital emergency department, clinic). note: this modifier is not to be used for physician reporting of multiple e/m services performed by the same physician on the same date. for physician reporting of all outpatient evaluation and management services provided by the same physician on the same date and performed in multiple outpatient setting(s) (eg, hospital emergency department, clinic), see evaluation and management, emergency department, or preventive medicine services codes. | 52 | Reduced services: under certain circumstances a service or procedure is partially reduced or eliminated at the discretion of the physician or other qualified health care professional. under these circumstances the service provided can be identified by its usual procedure number and the addition of modifier 52, signifying that the service is reduced. this provides a means of reporting reduced services without disturbing the identification of the basic service. note: for hospital outpatient reporting of a previously scheduled procedure/service that is partially reduced or cancelled as a result of extenuating circumstances or those that threaten the well-being of the patient prior to or after administration of anesthesia, see modifiers 73 and 74 (see modifiers approved for asc hospital outpatient use). | 77 | Repeat procedure by another physician or other qualified health care professional: it may be necessary to indicate that a basic procedure or service was repeated by another physician or other qualified health care professional subsequent to the original procedure or service. this circumstance may be reported by adding modifier 77 to the repeated procedure or service. note: this modifier should not be appended to an e/m service. | 79 | Unrelated procedure or service by the same physician or other qualified health care professional during the postoperative period: the individual may need to indicate that the performance of a procedure or service during the postoperative period was unrelated to the original procedure. this circumstance may be reported by using modifier 79. (for repeat procedures on the same day, see modifier 76.) | 95 | Synchronous telemedicine service rendered via a real-time interactive audio and video telecommunications system: synchronous telemedicine service is defined as a real-time interaction between a physician or other qualified health care professional and a patient who is located at a distant site from the physician or other qualified health care professional. the totality of the communication of information exchanged between the physician or other qualified health care professional and the patient during the course of the synchronous telemedicine service must be of an amount and nature that would be sufficient to meet the key components and/or requirements of the same service when rendered via a face-to-face interaction. modifier 95 may only be appended to the services listed in appendix p. appendix p is the list of cpt codes for services that are typically performed face-to-face, but may be rendered via a real-time (synchronous) interactive audio and video telecommunications system. | CC | Procedure code change (use 'cc' when the procedure code submitted was changed either for administrative reasons or because an incorrect code was filed) | FS | Split (or shared) evaluation and management visit | GX | Notice of liability issued, voluntary under payer policy | KX | Requirements specified in the medical policy have been met | PD | Diagnostic or related non diagnostic item or service provided in a wholly owned or operated entity to a patient who is admitted as an inpatient within 3 days | PO | Excepted service provided at an off-campus, outpatient, provider-based department of a hospital | Q0 | Investigational clinical service provided in a clinical research study that is in an approved clinical research study | Q1 | Routine clinical service provided in a clinical research study that is in an approved clinical research study | Q5 | Service furnished under a reciprocal billing arrangement by a substitute physician or by a substitute physical therapist furnishing outpatient physical therapy services in a health professional shortage area, a medically underserved area, or a rural area | QJ | Services/items provided to a prisoner or patient in state or local custody, however the state or local government, as applicable, meets the requirements in 42 cfr 411.4 (b) | SA | Nurse practitioner rendering service in collaboration with a physician | UD | Medicaid level of care 13, as defined by each state | XP | Separate practitioner, a service that is distinct because it was performed by a different practitioner | XS | Separate structure, a service that is distinct because it was performed on a separate organ/structure |
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| 2013-01-01 | Changed | Medium Descriptor changed. |
| 2012-01-01 | Added | Added |
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