Connection arrangement for establishing a fluid connection between a medical device and a patient-side coupling unit , wherein the connection arrangement comprises - a supply hose , - a patient-side connection piece , - a flexible fluid measurement hose and - an adapter comprising a rigid adapter tube (13.1, 14.1) and an adapter tube holder (12.1, 12.2), wherein the supply hose - is connected or connectable to the medical device and - is connected to the patient-side connection piece , wherein the supply hose and the patient-side connection piece together establish or are able to establish at least one fluid connection between the medical device and the patient-side coupling unit , wherein the patient-side connection piece holds the adapter tube holder (12.1, 12.2), wherein the adapter tube (13.1, 14.1) holds a patient-side end section (EA) of the fluid measurement hose , wherein the adapter tube holder (12.1, 12.2) - completely or at least partially surrounds the adapter tube (13.1, 14.1) and - holds, in a specified position relative to the patient-side connection piece , the end section (EA) of the fluid measurement hose that is held by the adapter tube (13.1, 14.1), wherein the connection arrangement establishes or is able to establish a measurement fluid connection, which comprises the fluid measurement hose , between a fluid measurement device and a specified fluid removal position (X) located inside the patient-side connection piece and wherein the patient-side end of the adapter tube (13.1, 14.1) is located at the fluid removal position (X). wherein the connection arrangement comprises - a supply hose , - a patient-side connection piece , - a flexible fluid measurement hose and - an adapter comprising a rigid adapter tube (13.1, 14.1) and an adapter tube holder (12.1, 12.2), - a supply hose , - a patient-side connection piece , - a flexible fluid measurement hose and - an adapter comprising a rigid adapter tube (13.1, 14.1) and an adapter tube holder (12.1, 12.2), wherein the supply hose - is connected or connectable to the medical device and - is connected to the patient-side connection piece , - is connected or connectable to the medical device and - is connected to the patient-side connection piece , wherein the supply hose and the patient-side connection piece together establish or are able to establish at least one fluid connection between the medical device and the patient-side coupling unit , wherein the patient-side connection piece holds the adapter tube holder (12.1, 12.2), wherein the adapter tube (13.1, 14.1) holds a patient-side end section (EA) of the fluid measurement hose , wherein the adapter tube holder (12.1, 12.2) - completely or at least partially surrounds the adapter tube (13.1, 14.1) and - holds, in a specified position relative to the patient-side connection piece , the end section (EA) of the fluid measurement hose that is held by the adapter tube (13.1, 14.1), - completely or at least partially surrounds the adapter tube (13.1, 14.1) and - holds, in a specified position relative to the patient-side connection piece , the end section (EA) of the fluid measurement hose that is held by the adapter tube (13.1, 14.1), wherein the connection arrangement establishes or is able to establish a measurement fluid connection, which comprises the fluid measurement hose , between a fluid measurement device and a specified fluid removal position (X) located inside the patient-side connection piece and wherein the patient-side end of the adapter tube (13.1, 14.1) is located at the fluid removal position (X). <EOS>