Proctoclysis is also known as rectal infusion, a Murphy drip, or rectoclysis.1 It is defined as the slow infusion of fluids and/or medications into the rectum as a therapeutic intervention. John Benjamin Murphy, an American surgeon, introduced the infusion of rectal saline solution to treat patients with peritonitis in 1909.2,3 This infusion technique was used in World War I to treat soldiers in hypovolemic shock. Proctoclysis was popular during times when intravenous techniques were less advanced.4 With the widespread use of intravenous (Chapters 59 and 61, 62, 63, 64) or intraosseous infusion (Chapter 70) techniques, proctoclysis has become less favorable and is rarely used in Emergency Medicine.1 It still plays an important role in the resuscitation and treatment of critically ill patients in remote or rural settings, especially by Emergency Medical Technicians (EMTs).
Proctoclysis can be used when sterile fluids are scarce. Nonsterile fluids (e.g., boiled water or tap water) can be infused into the rectum to provide hydration. Proctoclysis is a relatively easy procedure to perform and does not require health care providers skilled at intravenous cannulation. Multiple medications can be quickly and efficiently absorbed through rectal mucosa.5-9 In recent years, the Macy catheter (Figure 91-1) has been successfully used to facilitate proctoclysis with fewer complications and higher satisfaction among patients receiving palliative care, those in the Emergency Department, and those in the Intensive Care Unit.5,6,10-14 The Macy catheter has proven that proctoclysis can be used as an alternative and efficient route for medication and fluid infusion in the modern era.
The Macy catheter. A. The catheter. B. The labeled catheter. (Courtesy of Hospi Corp.)
ANATOMY AND PATHOPHYSIOLOGY
An understanding of the anatomy of the anorectal canal is necessary to perform proctoclysis. This anatomy is covered in Chapter 88 on anoscopy. The rectosigmoid junction is about 10 to 15 cm proximal to the anus, at which point the lumen sharply angulates anteriorly and to the left. Rectal catheters used for proctoclysis are normally inserted 7.5 to 10 cm (i.e., 3 to 4 inches) from the anal verge in adult patients.
Fluids and medications are absorbed across epithelial cells or via tight junctions between mucosal cells.15 The rectum does not absorb sodium, chloride, or water well from isotonic solutions. The colon has sufficient capabilities to absorb these substances. When infused via the rectum, drugs migrate into the sigmoid and descending colon. Depending on specific drug composition and administration volume, spreading can vary with a maximal migration generally being reached within 1 hour. The bioavailability is similar to giving the medication orally.