How many types of APD are described?

• A. Four types: CCPD, intermittent PD, nightly and day
• B. Three types: CCPD, intermittent PD, nocturnal PD
• C. Five types: CCPD, intermittent PD, nightly, daytime, and tidal PD
• D. Two types: CCPD and intermittent PD

Answer: (A)

APD modalities are grouped by when the exchanges happen and whether a cycler runs continuously. The four commonly described types are CCPD, intermittent PD, nocturnal (nightly) PD, and daytime PD. CCPD uses a cycler to perform a sequence of exchanges automatically, usually overnight. Intermittent PD refers to PD done intermittently, not as a full continuous overnight cycle. Nocturnal or nightly PD describes exchanges performed during the night with the cycler. Daytime PD describes exchanges done during the day, which can be manual or with a cycler in daytime sessions. Some texts mention tidal PD, but it’s not counted as a separate APD type in this framework. So four types are described.