10.1 Types of Percutaneous Tubes and Drains

Types of Percutaneous Tubes and Drains

Quick Summary: Blueprint statement 010305 requires knowledge of "types of percutaneous tubes/drains (e.g., nephrostomy, gastrostomy, surgical drain)." Domain II Task 3 and Domain III Task 3 then build intervention and management questions on top of that knowledge, together worth 13 scored items — about 12% of the exam. Every one of those items assumes you can name the device from a scenario description.

Ostomy nurses are consulted for percutaneous tubes far more often than the literature suggests, because the consult is almost never "manage the tube" — it is "this tube is leaking and the skin is destroyed." Solving that requires knowing what is inside the tube, because effluent chemistry drives every containment decision that follows.

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The Two Functional Families

Percutaneous devices divide into two families with entirely different logic:

• Access devices are placed to put something in (enteral feeding, medication) or to provide a route for repeated access. Failure means the route is lost.
• Drainage devices are placed to take something out (urine, bile, gastric content, wound fluid, abscess collections). Failure means fluid accumulates where it should not.

Many tubes do both. A gastrostomy tube feeds most patients but is placed for decompression in others, such as a malignant bowel obstruction — the same hardware with an opposite purpose and an opposite set of nursing priorities.

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Gastrointestinal Access and Decompression Tubes

The clinical consequence of the effluent column is direct. Gastric leakage produces a chemical burn from acid; jejunal leakage produces proteolytic digestion of the epidermis that resembles the peristomal damage seen around a high-output ileostomy. A jejunostomy leak therefore escalates to a pouched containment strategy far earlier than a gastrostomy leak of the same volume.

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Urinary Tract Drainage

A nephrostomy tube is placed percutaneously through the flank into the renal pelvis under imaging guidance, most often for ureteral obstruction from malignancy, stone disease, or stricture. Three facts recur on examinations:

1. It drains urine from a single kidney above the level of the obstruction, so falling output on one side is not offset by the other kidney's output — it signals blockage or dislodgement in that tube.
2. The renal pelvis holds roughly 5 to 10 mL, so any ordered flush uses a small volume of sterile normal saline, instilled gently and never aspirated forcefully.
3. It is a gravity drainage system that is not clamped for convenience; clamping raises intrarenal pressure and risks pyelonephritis.

A ureteral stent placed percutaneously or cystoscopically is a different device: it is internal, it does not exit the skin, and it produces no peritubular skin problem. Candidates confuse the two because both relieve ureteral obstruction.

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Biliary Drainage

A percutaneous transhepatic biliary drain (PTBD) exits the right upper quadrant and may be external, internal-external, or capped. Bile is alkaline, detergent-like, and intensely irritating; a leaking biliary drain denudes skin quickly and is a common ostomy-nurse consult even though no stoma exists. Output that turns from bile-stained to serous, or that drops sharply while the patient becomes jaundiced, indicates occlusion or migration.

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Surgical Drains

Closed suction drains work only when the reservoir is recompressed after every emptying; a bulb found fully expanded has lost its vacuum and is functionally a passive drain. A Penrose, by contrast, has no reservoir at all — output volume can only be estimated from dressing saturation, which is precisely why Penrose sites are the classic candidate for a pouching system.

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Retention Mechanism Determines Who May Touch It

The single most exam-relevant classification is not anatomic but mechanical:

• Balloon-retained (most replacement G-tubes, many nephrostomy and biliary catheters): an internal balloon inflated with sterile water, not saline or air, because saline crystallises and air diffuses out. Deflating the balloon allows bedside exchange within a mature tract.
• Internal bumper / mushroom-retained (original PEG placement): removal requires endoscopy or firm traction by a qualified provider. A nurse does not remove these.
• Pigtail / locking-loop (nephrostomy, abscess drains): a suture-locked curl inside the cavity. Pulling on the tube without unlocking the loop can lacerate tissue.
• Sutured or safety-pinned (Penrose, some surgical drains): advanced or shortened only on an explicit order.

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Tract Maturity: The Clock That Governs Everything

A percutaneous tract is not a stoma. It is a fibrous channel that forms over roughly four to six weeks after placement, and its maturity governs the response to dislodgement.

Placement ──────────────► 4–6 weeks ──────────────► Mature tract
   IMMATURE TRACT                          MATURE TRACT
   Dislodgement = emergency                Dislodgement = urgent
   DO NOT reinsert                         Tract may close in hours
   Blind reinsertion risks free            Preserve patency, notify
   perforation and peritonitis             provider promptly

That single distinction — immature versus mature — is the highest-yield fact in this chapter and reappears in the complications section.