Generating the Polysomnography Report



Generating the Polysomnography Report


Jon W. Atkinson





LEARNING OBJECTIVES

On completion of this chapter, the reader should be able to:



  • 1. Describe the purpose of the sleep study report.


  • 2. Define the parameters to be reported according to the American Academy of Sleep Medicine (AASM) guidelines set forth in The AASM manual for the scoring of sleep and associated events: Rules, terminology and technical specifications version 2.5.

    a. Cite the definitions and use formulae to calculate common sleep architectural parameters.

    b. Cite the definitions and use formulae to calculate common event parameters.


  • 3. Derive and utilize histograms.


  • 4. Develop derivations of unique/detailed event parameters and tables.


  • 5. Validate the use of summary reports.


  • 6. Describe archiving and data storage procedures.


  • 7. Describe the AASM reporting guidelines for Home Sleep Apnea Testing set forth in The AASM manual for the scoring of sleep and associated events: Rules, terminology and technical specifications version 2.5.




KEY TERMS

Polysomnography

Reporting

Data analysis

Home Sleep Apnea Testing (HSAT)


In the early days of sleep medicine, polysomnographic studies were recorded on paper. Utilizing a paper speed of 10 mm per second, these records usually contained 800 to 1,000 pages of data. The purpose of the polysomnographic report was to summarize these data, presenting an overview of the patient’s sleep architecture and allowing for comparisons among sleep studies (1). In the late 1960s, a standard scoring system was developed to provide guidelines for staging human sleep, and this scoring system was the gold standard for decades (2). This document was based on data from normal, young adult subjects. As the practice of clinical sleep medicine evolved and a variety of sleep-related pathologies were recognized, it became clear that additional descriptive statistics were necessary to convey adequately the various aspects of normal and abnormal sleep. Guidelines for identifying and scoring arousals (3), periodic limb movements (PLMs) (4), and respiratory events (5) were then developed in an effort to standardize the tabulation of these data.

Manual scoring and data tabulation was a daunting task, even for a very experienced technologist, often consuming hours of time per recording. Before the advent of personal computers to assist with “number crunching,” the tabulation of data and generation of the report summary sometimes involved more time than the identification of sleep stages and abnormal events. Today, a polished report representing the visual scoring of sleep and events, replete with graphics and charts, can typically be produced within 1 to 2 hours (depending on the complexity of the recording and the severity of the patient’s condition). This type of report would have been virtually impossible to produce in the formative years of polysomnographic technology.

The advent of digital polysomnography recording systems with intrinsic scoring and data tabulation has rendered the report generation task much less cumbersome. Although this represents a significant advance in technology, it has also given rise to several problems:



  • The digitization of polysomnographic data allows use of various automated functions, including computer-assisted or automated scoring. To date, most of these functions have not been validated for clinical use.


  • Automated scoring is generally not accurate for sleep staging and abnormal event recognition. This is particularly true in light of the high incidence of mechanical, physiologic, and medication-induced artifacts that can occur in unison or in combination. Computer-scored recordings must always be reviewed and edited by a competent technologist. In essence, the technologist must manually corroborate the sleep stage scoring and review/edit computer-scored abnormal events, such as apneas, hypopneas, oxygen desaturations, and limb movements. This editing process is generally more time-consuming and cumbersome than scoring the record manually.


  • Reliance on automated data tabulation and report generation built into these programs allows the
    technologist to be uninformed about the theory, concepts, and formulae involved in the generation of these reports.



    • The knowledge base related to the theory, concepts, and formulae used to generate reports becomes very important when installing new systems and developing report templates or developing specialized reports or data points. The data points in a report must be checked for accuracy and appropriateness before the report is used to present patient data. It is not uncommon to find inaccurate numbers in the initial reports developed following a new installation.


    • Back in the days of analog paper-based recordings, the manual data tabulation theories, concepts, and formulae presented in this chapter were utilized many times daily. There was continuous reinforcement of this knowledge and a practical reason for learning and maintaining this information. Currently, many technologists have little exposure to this knowledge and do not spend time exploring its intricacies. Consequently, reports may be of lesser quality or relevance than those designed and maintained by knowledgeable users.


PURPOSE OF A SLEEP STUDY REPORT

The purpose of the polysomnographic report is dependent on the needs of the end user. This may be the interpreting physician, the referring physician, the homecare company or durable medical equipment (DME) supplier, or the third-party payer. With the advent of digital recordings, there is an ability to overanalyze and therefore produce reports with overwhelming, often superfluous amounts of data. Fortunately, it is also easy to develop multiple reports using the same data to meet the needs of multiple users.

For in-depth data analysis or research purposes, a report can contain multiple tables, statistics, graphs, and customized charts to meet the needs of the interpreter or research project. Histographic summaries can correlate events with sleep staging, body position, and treatment settings. Event tabulations, percentages, and indices can be provided for every conceivable condition encountered during the study. A report of this nature can be quite lengthy, but not necessarily practical. Figure 42-1 is an example of a Split-Night Study—Long Report for Sleep Center Use.






Figure 42-1 Split-night study. CPAP, continuous positive airway pressure; PLM, periodic limb movement; REM, rapid eye movement; TIB, time in bed; TST, total sleep time; WASO, wake after sleep onset (long report for Sleep Center use and third-party payer).







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)







Figure 42-1 (continued)

A report generated for clinical use should be relevant, concise, and easily understood by the referring physician (6). This type of report generally serves the needs of the third-party payer as well. It typically includes a summary of sleep architecture, respiratory events, oxygen saturation levels, limb movements, arousals, and heart rate (HR) in a tabular form. A graphic summary is usually also presented. This report should not exceed two or three pages at the most. Figure 42-2 is an example of a Split-Night Study—Referring Physician Report.






Figure 42-2 Split-night report. CPAP, continuous positive airway pressure; PLM, periodic limb movement; REM, rapid eye movement; RERA, respiratory effort-related arousal; TIB, time in bed; TST, total sleep time; WASO, wake after sleep onset (referring physician report).







Figure 42-2 (continued)







Figure 42-2 (continued)







Figure 42-2 (continued)







Figure 42-2 (continued)







Figure 42-2 (continued)







Figure 42-2 (continued)


A report to the homecare company or DME provider may be even more abbreviated and limited to basic sleep architecture, respiratory events, arousals, and oxygen saturation summaries. For basic positive airway pressure (PAP) treatment, the primary requirements for DME reimbursement are total recording time (TRT), total sleep time (TST), the apnea-hypopnea index (AHI), and the oxygen (O2) saturation nadir. Figure 42-3 is an example of a Split-Night Report—DME/Insurance Co. Report.

The AASM manual for the scoring of sleep and associated events: Rules, terminology and technical specifications includes scoring rules for sleep stages, arousals, respiratory events, cardiac events, and movement events and provides the recommended minimum information to be included in a polysomnographic report. The following summarizes the AASM manual’s recommended parameters for inclusion in the polysomnographic report (7).






Figure 42-3 Split-night report (durable medical equipment/Insurance Co. report). CPAP, continuous positive airway pressure; PLM, periodic limb movement; REM, rapid eye movement; TIB, time in bed; TST, total sleep time; WASO, wake after sleep onset.







Figure 42-3 (continued)







Figure 42-3 (continued)







Figure 42-3 (continued)


Recording Parameters

The AASM manual recommends listing the recording parameters employed during the sleep study in the report. These include the following:



  • Electroencephalogram (EEG) derivations


  • Electrooculogram (EOG) derivations


  • Chin electromyogram (EMG)


  • Leg EMG derivations


  • Airflow parameters


  • Effort parameters


  • Oxygen saturation


  • Body position


  • Electrocardiogram (ECG)

These are the typical parameters recorded. Although not specifically addressed, additional parameters such as carbon dioxide (CO2) monitoring (end-tidal or transcutaneous) and esophageal pH monitoring should also be included in the list of recording parameters if they are utilized.

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Dec 12, 2019 | Posted by in NEUROLOGY | Comments Off on Generating the Polysomnography Report

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