Anesthesia Coding Alert

Anesthesia providers sometimes provide one-lung ventilation for procedures when the surgeon needs a quiet field to operate on, as with lung resection, thoracic aortic repair and some thoracic vertebrae or gastric surgeries. Although an ASA code exists for one-lung ventilation, the new code is not in CPT, so providers are finding that reimbursement is difficult to obtain.
 
The ASA code for one-lung ventilation is 00541 (Anesthesia for intrathoracic procedures, excluding procedures on the heart, great vessels, trachea; utilizing one lung ventilation) and has 15 base units (BUs). If the patient's carrier only accepts CPT codes, use 00540 (Anesthesia for thoracotomy procedures involving lungs, pleura, diaphragm, and mediastinum [including surgical thoracoscopy]; not otherwise specified). This code makes no assumption about how the lungs are ventilated during the procedure. Because the anesthesia work involved for ventilating one lung is greater than that of standard ventilation, the ASA relative value guide awards that additional work with a higher BU 00541 has 15 BUs compared to 13 units for 00540.
 
"Any thoracotomy procedure could involve one-lung ventilation, but lung resection (32520-32525, Resection of lung; with resection of chest wall; with reconstruction of chest wall, without prosthesis; with major reconstruction of chest wall, with prosthesis) is the most common," says Samantha Mullins, CPC, an anesthesia coder with University of Alabama HSF-MSO specialty coding in Birmingham.

Getting Paid for the New Code

Four options exist to obtain ethical reimbursement for anesthesia for one-lung ventilation based on the carrier:

1. Code the procedure with 00540 for carriers that will not accept 00541, and append modifier -23 (Unusual anesthesia) to signify that something is different about this case. "Modifier -23 can be used to notify the carrier of unusual anesthesia for any procedure with unusual circumstances, for procedures that do not have a specific CPT anesthesia code associated with them, or for procedures with codes that the carrier will not accept," Mullins says. But some carriers will only allow modifier -23 if the procedure is performed under general anesthesia.

2. Bill 00540 with modifier -22 (Unusual procedural services) appended to indicate that the service provided was greater than what is normally required.
 
3. Refrain from coding for the one-lung ventilation until CPT accepts it and report the associated procedures instead. "One-lung anesthesia for thoracotomies is more time-consuming and work-intensive than other types of chest surgery that don't require this special type of ventilation. Because all our insurers pay according to CPT 2002, we cannot use 00541," says Scott Groudine, MD, an Albany, N.Y., anesthesiologist. "Therefore, we can't code for this type of ventilation. A double lumen tube or other device that permits one-lung ventilation can add from five to 30 minutes to a surgical procedure, which is recovered in the time component of the anesthesia fee. Additionally, an A-line (36620, Arterial catheterization or cannulation for sampling, monitoring or transfusion [separate procedure]; percutaneous) is usually warranted when one-lung ventilation is performed. The charge for this monitor is also recoverable."

4. Report the surgical code. Medicaid in New York and many other areas pays for anesthesia reported with surgical codes rather than anesthesia codes, Groudine says. Coding with 32520 is an option in this situation. However, Groudine also notes that one-lung anesthesia is usually provided with a double lumen tube, which Medicare carriers do not pay extra for.

Billing Commercial Carriers

Although many carriers reject 00541, coders should use this code for commercial carriers. If you use 00541, include extra documentation with the claim, such as a copy of the page from ASA's guide listing the code. Any notes specifying details about the procedure may also help.

Future Coding for One-Lung Ventilation

Mullins believes that 00541 for one-lung ventilation was a needed addition to anesthesia codes. "The anesthesia team needs to monitor the patient more closely during a case with one-lung ventilation than with both," she explains. "This fact alone justifies a separate code with a higher unit value for times when one-lung ventilation is used."
 
It may be several years before new ASA codes are included in CPT and accepted across the board. "Our facility opts to use only anesthesia codes that are included in CPT, so we aren't able to use 00541," Mullins says. "It would be nice to have 00541 added to CPT so that anesthesiologists who are providing the service could be paid adequately for it."
 
"Having the new code is probably a good first step in obtaining CPT status for a new code that accurately differentiates the work involved between thoracotomies that require one-lung ventilation and those that don't," Groudine adds.