3.2 Surgical Drains and Suction Systems

Surgical drains are vital therapeutic devices used to remove air, blood, serum, bile, or intestinal contents from the surgical site. The accumulation of these fluids can create dead space, increase the risk of infection, compromise tissue perfusion, and delay wound healing. Drains are generally categorized by their mechanism of action: passive or active.

Passive Drains

Passive drains function without the use of negative pressure (suction). They rely on gravity, capillary action, and overflow to facilitate the egress of fluid from the wound to the exterior dressing or a collection bag.

• Open Systems vs. Closed Systems: Open passive drains allow fluid to drain directly onto the skin and dressing, which increases the risk of retrograde bacterial migration and skin maceration. Closed passive systems drain into a sterile bag, minimizing these risks.

Penrose Drain

The Penrose drain is the most common type of passive drain. It is a soft, flexible, tubular latex or silicone conduit. Because it is an open system, fluid drains directly onto the surrounding surgical dressing, which requires frequent changing to prevent maceration of the skin. Penrose drains are often utilized in procedures where significant drainage is expected but precise measurement is not critical, or in contaminated areas like a peri-appendiceal abscess. A critical step when placing a Penrose drain is to secure a sterile safety pin through the external portion of the drain; this physical barrier prevents the flexible tube from inadvertently retracting completely into the wound cavity due to internal tissue movements.

T-Tube

A T-tube is a specialized passive drain constructed of silicone or latex, shaped like a 'T'. It is specifically used for insertion into the common bile duct (CBD) during an open cholecystectomy or common bile duct exploration. It allows bile to drain externally while the duct heals, preventing stricture formation and bile peritonitis. The external end is connected to a closed gravity drainage bag. The CSFA must monitor bile output: normal output is approximately 200 to 500 mL of dark green to golden brown bile per day. A sudden drop in bile output may indicate obstruction or kink in the system.

Active Drains

Active drains, also known as closed-suction drains, utilize continuous negative pressure to actively pull fluid from the surgical site into a sealed collection reservoir. This closed system significantly reduces the risk of ascending infection compared to open passive drains and allows for accurate measurement of the drainage output.

Jackson-Pratt (JP) Drain

The Jackson-Pratt drain features a flat, fenestrated (perforated) internal catheter connected to a clear, bulb-shaped reservoir. Negative pressure is established by squeezing the bulb to expel air and then sealing the cap. As the bulb slowly re-expands, it creates a gentle suction. JP drains are frequently used in neurosurgery, neck dissections, abdominal surgery, and breast surgery (e.g., mastectomies) where precise control of dead space and measurement of serosanguinous fluid is required. The CSFA should note that the bulb must remain compressed to maintain suction; a fully expanded bulb provides no therapeutic benefit.

Hemovac Drain

The Hemovac drain operates on the same principle as the JP drain but utilizes a larger, spring-loaded, drum-shaped reservoir. It can generate a higher level of negative pressure and accommodate a larger volume of fluid. Hemovacs are predominantly used in major orthopedic procedures, such as total joint arthroplasties (hips and knees), where substantial postoperative bleeding is anticipated. In some orthopedic settings, these systems are modified for autologous blood reinfusion (salvage systems like the ConstaVac), allowing the patient's own shed blood to be filtered and reinfused postoperatively.

Chest Tubes (Thoracostomy Tubes)

Chest tubes are specialized active drains inserted into the pleural space to evacuate air (pneumothorax), blood (hemothorax), or serous fluid (pleural effusion). The primary goal is to re-establish the normal negative pressure within the pleural cavity, allowing the lung to fully re-expand. Chest tubes must be connected to a specialized closed water-seal drainage system (e.g., Pleur-evac). These systems typically have three chambers:

1. Collection Chamber: Collects the fluid draining from the patient.
2. Water-Seal Chamber: Contains sterile water (usually filled to the 2 cm mark) and acts as a one-way valve, allowing air to escape from the pleural space but preventing atmospheric air from re-entering. Continuous bubbling in this chamber indicates an air leak in the system or patient's lung.
3. Suction Control Chamber: Regulates the amount of negative pressure applied to the pleural space, usually controlled by the water level in this chamber (typically -20 cm H2O), regardless of the wall suction setting.

The CSFA must handle chest tubes with extreme care to maintain the sterile closed system. If the tubing disconnects, the chest tube must be immediately clamped to prevent atmospheric air from entering the pleural cavity, which would cause a tension pneumothorax.

Principles of Drain Management

When assisting with drain placement, the CSFA should adhere to several key principles:

• Separate Incision: Drains should ideally exit the body through a separate stab incision adjacent to the main surgical wound. Exiting through the primary incision increases the risk of wound infection and dehiscence.
• Securing the Drain: Drains must be securely anchored to the skin using a heavy, non-absorbable suture (e.g., 2-0 Silk or Nylon) using a suture technique like a purse-string or "Roman sandal" wrap to prevent accidental dislodgement.
• Asepsis: Strict aseptic technique must be maintained when connecting drains to their respective reservoirs.
• Milking vs. Stripping: If a drain becomes clogged with a clot, it may be gently "milked" by squeezing the tube. "Stripping" (sliding pinched fingers along the tubing) is contraindicated because it generates dangerously high negative pressures (up to -300 mmHg) that can suck tissue or organs into the drain fenestrations.
• Removal: During removal, the anchoring suture is cut, and the patient is asked to perform a Valsalva maneuver (or take a deep breath and hold) while the drain is pulled in one smooth, continuous motion to prevent air from entering the tract.