A surgical drain is a temporary medical device used after an operation to remove unwanted fluid or air from the surgical site. Excess fluid accumulation can prevent tissues from healing properly and increase the risk of complications. By drawing this material away from the wound bed, the drain helps the body recover more smoothly and allows healthcare providers to monitor the internal healing environment.
The Purpose and Function of Surgical Drains
Surgical drains prevent the accumulation of natural body fluids in the space created by surgery, often called “dead space.” Without drainage, this space can fill with blood or lymphatic fluid, leading to a hematoma (a collection of blood) or a seroma (a collection of clear, yellowish fluid). These collections delay wound healing, cause pain, and provide a medium for bacteria, increasing the potential for infection.
Drains function through two mechanisms: passive and active drainage. Passive drains rely on natural physics, such as gravity and capillary action, to draw fluid out of the body. For these to work effectively, the exit point of the drain must be positioned lower than the wound site to allow the fluid to flow downward.
Active drains utilize a negative pressure system, often described as suction, to pull fluid from the surgical site into a collection reservoir. This continuous or intermittent suction is more efficient and allows the drain to be used in various body locations. Active systems maintain a closed environment, reducing the risk of infection.
Identifying Common Types of Post-Surgical Drains
The choice of drain depends on the type of surgery, the amount of fluid expected, and the location of the wound. The Jackson-Pratt (JP) drain is a common active, closed-suction system consisting of a flexible tube connected to a small collection bulb. Suction is created by manually compressing the bulb and sealing it with a plug, causing the bulb to expand as it draws fluid. JP drains are used for surgeries that produce low to moderate amounts of fluid.
The Hemovac is another active, closed-suction drain, often used for procedures generating larger volumes, such as major joint replacements. It uses a collapsible, cylindrical or accordion-shaped container instead of a bulb. When compressed and sealed, a spring mechanism within the reservoir creates the negative pressure to pull fluid from the wound.
The Penrose drain is the most common example of a passive, open-ended system. It is a soft, flat, ribbon-like latex tube that allows fluid to seep out onto an absorbent dressing placed over the exit site. Relying on overflow and gravity, the Penrose drain is often used for superficial wounds or to drain thick, infected fluids where lower pressure is desired.
Daily Management and Monitoring of Drain Output
Proper daily management of a surgical drain is important for recovery. For active drains, maintaining suction is paramount, requiring regular emptying of the reservoir before it loses its compressed shape. To re-establish negative pressure, the plug must be removed, the fluid poured out, and the reservoir fully squeezed flat before the plug is replaced.
Monitoring and recording the output volume must be done accurately, typically every eight to twelve hours, to track healing progression. The total volume collected is measured using a calibrated cup and documented on a dedicated drain record sheet. This record-keeping allows the surgeon to identify trends and determine the appropriate time for drain removal.
The drain site should be cleaned daily to prevent infection, and the tubing must be secured to prevent accidental tugging or dislodgement. The care team should be immediately notified if warning signs appear.
Fluid Characteristics
The color and consistency of the fluid must also be documented, as this indicates the type of fluid being drained. Initially, the fluid is often sanguineous (dark red and bloody), which then transitions to serosanguineous (a pinkish-red mixture of blood and clear serum). As the wound heals, the drainage should become serous, appearing pale yellow or straw-colored and thin.
Warning Signs
Notify the care team immediately if any of the following occurs:
- The fluid suddenly changes to bright red, indicating fresh bleeding.
- The fluid becomes thick and cloudy with a foul odor, suggesting infection.
- The drain site shows signs of increasing redness, swelling, or severe pain.
- There is a sudden and complete cessation of output, which may indicate a blockage or kink in the tubing.
Criteria and Process for Drain Removal
The decision to remove a surgical drain is based on specific clinical criteria, not a fixed timeline. The primary factor is the volume of fluid draining over a 24-hour period, indicating that the body’s internal fluid production is decreasing. Removal is typically appropriate when the output consistently falls below a threshold, usually 20 to 50 milliliters over 24 hours.
This low-volume threshold confirms that the dead space has been sufficiently obliterated and that the remaining fluid can be reabsorbed by the body. Waiting for this low output prevents premature removal, which could lead to a seroma or hematoma. The consistency of the fluid is also considered, with clear, serous fluid being preferable.
The removal procedure is generally quick and performed by a nurse or physician. The process involves releasing any suction, removing the suture holding the tube in place, and having the patient take a deep breath as the tube is smoothly pulled out. While the sensation may feel unusual, it typically causes only minimal and brief discomfort. The exit site is then covered with a small dressing and usually closes naturally within a few days.