by Joel Moorhead, MD, PhD, CPC, and Faye Kelly, RHIT, CCS
Our productivity targets were ambitious under ICD-9-CM. Meeting productivity targets under ICD-10 probably looks even more challenging. It is tempting to accept the codes and DRGs that our encoders output and move quickly to the next admission on our list. This approach might often serve us well, but maybe not for all admissions.
Importance of clinical anatomy to coding
Every day of coding under ICD-10 brings fresh opportunities to expand our clinical knowledge. Here’s an example. Thoracic outlet syndrome (TOS) is a condition in which nervous system and vascular structures are compressed as they travel from neck to arm through a series of spaces bounded by the first rib, the clavicle, and the scalene muscles. Structures vulnerable to compression include the brachial plexus (a network of nerves) and the subclavian artery and vein. The blood vessels or nerves alone can be compressed, or both.
“Thoracic outlet syndrome” is an inclusion term under G54.0 (brachial plexus disorders). No option is offered for TOS causing only vascular compression. Two coding challenges arise when surgery is performed.
The first challenge is that surgery for TOS often involves excision of the first rib. It would be tempting to code the root operation as Excision. However, the Introduction to the ICD-10-PCS Official Code Set states, “The root operation identifies the objective of the procedure.” The objective of the first rib excision may be to free or decompress the subclavian or axillary vein, a Release according to ICD-10-PCS structured health language. The ICD-10-PCS Reference Manual defines root operation Release as “Freeing a body part from an abnormal physical constraint by cutting or by use of force.” ICD-10-PCS pathway “Release – vein” leads us to separate procedure codes for the right and left versions of Release procedures for the subclavian (05N5---, 05N6---) and axillary (05N7--- and 05N8---) veins.
The second challenge might lead us to consider the complementary roles of the encoder and the ICD-10-CM/PCS code sets.
Using the ICD-10 official code sets
The second challenge is that the principal diagnosis may control the pathway that the encoder software follows for DRG assignment. Assigning principal diagnosis G54.0 (for inclusion term TOS) may result in a DRG in the 28-30 range (Spinal Procedures), which does not accurately identify the care provided. This disconnect between the DRG assignment and the realities of the admission might lead us to seek a more accurate and specific principal diagnosis.
We may think, “But the ICD-10-CM Alphabetic Index leads us to principal diagnosis G54.0 and TOS is an inclusion term under G54.0, so that’s the right code.” This is an opportunity for us to review the “How to Use the ICD-10-CM” section tucked into the very beginning of the ICD-10-CM Official Code Set, just after the Preface and Introduction. Step 5 under Steps to Correct Coding in this section directs, “Do not code from the Alphabetic Index without verifying the accuracy of the code in the Tabular List.” Alphabetic Index entry “Syndrome – thoracic outlet (compression)” directs us to G54.0. We find “thoracic outlet syndrome” as an inclusion term under Tabular List entry G54.0. This patient has vascular TOS, but not a brachial plexus disorder. So consulting the Tabular List did not verify the accuracy of G54.0 as the principal diagnosis.
Following the Steps to Correct Coding, we return to the Alphabetic Index and find that “Compression – vein” directs us to I87.1 (compression of vein). Tabular List entry I87.1 seems accurate and as specific as we can get to capture the realities of the condition being coded.
Encoder software programs and the ICD-10 official code sets can be viewed as separate resources that contribute to the coding process in different ways. Encoder software is good at saving us time. Some encoder software programs also offer access to Coding Clinic and other resources, and may link those resources to the codes that we are considering. But encoder software programs are not primary sources of authority for code assignment.
The ICD-10 official code sets are primary sources of authority for code assignment. Following each of the steps to correct coding helps us to develop a deeper understanding of the International Classification of Disease, and is valuable to verify the accuracy of encoder software output. Paper copies of the official code sets may be especially useful.
Reading and re-reading ICD-10-CM sections I–IV may be needed for us to develop a thorough understanding of conventions, coding guidelines, and rules for assigning principal and secondary diagnoses. Reading and re-reading applicable parts of the first 30-plus pages of the ICD-10-PCS code sets may be needed to understand important aspects of building accurate procedure codes.
Opening a paper manual to the page on which a code is indexed allows us to look at the organizational context in which the code is found. We can look at neighboring codes to see if any codes in the same or related categories will provide a more accurate code assignment. We can read inclusion terms, Excludes1 and 2 notes, and a variety of other interesting instructional notes. We can follow See, See also, and Code also notes to other sections of the classification. When we arrive at those other sections, we can begin the process of learning and discover anew.
Many of us have found current versions of the ICD-10 encoder software to be works in progress. We may suspect that an accurate and specific code exists, but fail to find an encoder pathway that takes us there. Experience paging through the paper code sets gives us a general idea where to look for a code that we believe exists but can’t find via the encoder. Once we have that general idea, we can look in the paper manual Alphabetic Index for all the subterms under all the headings that we think might be likely for the code that we think is there.
As an exercise, try using your encoder to find the most accurate and specific principal diagnosis for a patient admitted with cellulitis documented to be due to an infection complicating a left lower leg incision made three days earlier for a left saphenous vein ablation. Does the encoder take you to an accurate and specific code? If not, start at the beginning of the Steps to Correct Coding. Using the essential facts of the case, navigate the code set to find a better code. E-mail us for discussion if you want.
Conclusion
Country artist Lee Ann Womack said in a 1998 song, “I really hate her. I’ll think of a reason later.” Many of us probably felt this way about ICD-10 at first.
Maybe some of us still do. But some people grow on us as we get to know them better, and ICD-10 might grow on you as you get to know it better as well. Using the code sets themselves to complement your use of the encoder may grow your affection for ICD-10 in ways that may surprise you.
Editor’s note: Moorhead is clinical director for FairCode Associates, headquartered in Marco Island, Florida. E-mail him at jmoorhead@faircode.com. Kelly is an AHIMA-approved ICD-CM/PCS trainer and an account executive at FairCode Associates. E-mail her at fkelly@faircode.com.