7.2 Pneumatic Tube System

7.2 Pneumatic Tube System

Quick Answer: Send specimens by pneumatic tube (PTS) only when policy allows that specimen type. Pack with leak-proof primaries, absorbent material, biohazard bags, and foam inserts so nothing breaks or leaks in transit. Hand-carry items commonly restricted from PTS (often CSF, some blood bank products, and certain high-risk materials). If a carrier crashes or spills, stop unsafe use, contain with PPE, clean per spill SOP, document, and notify. If the system is down, use downtime hand-carry routes—especially for STATs.

The pneumatic tube system moves carriers through a network of tubes between nursing units, clinics, and the laboratory. For the MLA, PTS skill is not “stuff and send.” It is risk control: protect specimen integrity, protect workers who open carriers, and protect the physical plant from biohazard contamination.

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When PTS Is Appropriate

PTS is appropriate when all of the following are true under your laboratory and facility policy:

1. The specimen type is allowed on the tube system.
2. The container is sealed and not already leaking.
3. The sample is packed to survive acceleration, impact, and vibration.
4. Required temperature or time conditions can still be met (or an alternate transport is chosen).
5. The destination station is correct and in service.

Common good candidates (policy-dependent)

• Routine and many STAT blood tubes in plastic primary containers
• Properly sealed urine containers in secondary bags
• Some swab specimens in closed transport devices
• Documents/requisitions only when policy permits paper in carriers (many sites prefer electronic orders and ban loose needles/paper chaos)

When hand-carry is usually better or required

Always follow your SOP list of prohibited items. The exam tests the principle: not everything that fits in a carrier should be sent in a carrier.

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Packing to Prevent Breakage and Leakage

PTS carriers experience sudden starts, stops, and impacts. Packing is a safety control, not cosmetic padding.

Packing checklist

Technique tips

1. Inspect tubes and cups before packing—no cracks, no wet exteriors, no open tops.
2. Place specimens so they cannot rattle freely against hard carrier walls.
3. Use foam inserts designed for your carrier model when available; improvised wadding is inferior if it shifts.
4. Keep paperwork outside the biohazard bag or in a separate pouch if policy requires dry, uncontaminated forms.
5. Do not overfill the carrier; compressed bags rupture and lids pop.
6. Separate incompatible contents (for example, do not jam a leaking urine cup against unbagged blood tubes).
7. Wipe gross contamination from the outside of bags before loading so the next worker is not exposed when opening the station.

Biohazard bags

Secondary biohazard bags are standard for clinical specimens in transit inside the facility. Seal them. A half-open bag is not containment. If the primary leaks, the bag and absorbent should keep the carrier interior and tube network cleaner—and protect the person who opens the station.

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Restrictions Worth Memorizing

CSF (cerebrospinal fluid)

Many laboratories and hospitals require hand-carry for CSF because:

• Specimens are often difficult or painful to recollect
• Testing may include cell counts, differentials, culture, and rapid assays with time sensitivity
• Breakage or loss has outsized clinical impact

If policy says hand-carry CSF, do not send it by PTS to “save a walk,” even if the tube looks sturdy.

Blood bank products and some blood bank specimens

Policies often restrict PTS for:

• Blood components (RBCs, plasma, platelets) with temperature and product-integrity rules
• Certain compatibility specimens or special blood bank materials when identity and handling must be controlled face-to-face

Know the difference between a routine EDTA type-and-screen tube (may be PTS-allowed at some sites) and a blood product leaving the blood bank (often hand-delivered with documentation). Do not assume they share the same transport rules.

Known pathogens and high-risk materials

If a specimen is associated with a known highly infectious agent or other restricted category defined by infection control and laboratory policy, follow the special transport SOP. That may mean:

• Hand delivery only
• Enhanced packaging
• Designated routes and notification
• Refusal to use the general PTS network

The MLA does not invent exceptions during a busy shift.

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If a Tube Crashes or Spills

A crash means the carrier fails to arrive normally, jams, opens, or arrives damaged. A spill means blood or body fluid contaminates the carrier, station, or surrounding area—and potentially the tube system.

Immediate response principles

1. Do not casually dig through a soaked carrier with bare hands.
2. Don appropriate PPE (gloves at minimum; gown/face protection if splash risk).
3. Contain the spill; prevent tracking to clean floors and counters.
4. Rescue recoverable specimens only if safe and identifiable—a soaked, unlabeled tube may be lost.
5. Disinfect the carrier and station surfaces with approved EPA-registered disinfectant and correct contact time per spill SOP.
6. Remove the contaminated carrier from service until cleaned/dried per policy.
7. Notify the supervisor, engineering/PTS vendor contact, and infection control as required when the network may be contaminated or jammed.
8. Document the incident, specimen IDs affected, notifications, and recollection needs.
9. Arrange recollection promptly for irretrievable STATs and critical samples; communicate with the clinical unit.

Never shove a contaminated carrier back into the system “to get it out of the way.” That can spread biohazard contamination through the tube network.

After a network contamination event

Facilities may take zones offline for cleaning. Cooperate with downtime procedures rather than forcing sends into a dirty or disabled line.

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Downtime Procedures

PTS downtime happens: power loss, mechanical failure, software lockouts, contamination events, or planned maintenance.

MLA actions during downtime

A common failure mode is leaving STAT specimens in a dead station because “the tube usually works.” When the system is down, walk.

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Integrity Issues Unique to PTS

Even without a crash, tube transport can harm specimens:

• Hemolysis from rough transit or extreme temperature swings
• Lid failures on poorly seated containers
• Delays in a jam that exceed stability limits
• Mis-send to the wrong station if the destination code is wrong
• Lost carriers requiring search protocols

If a specimen arrives hemolyzed after PTS and policy links certain analytes to transport trauma, follow rejection/recollection rules. Document transport method when the LIS allows—it helps quality review.

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Scenarios

Scenario A — CSF
A nurse asks you to tube a CSF to the lab during a staffing shortage. Policy requires hand-carry. Hand-carry; do not improvise.

Scenario B — Soft packing
Three glass tubes rattle in an empty carrier with no foam. Repack with inserts and secondary bags before sending—or hand-carry if glass is restricted.

Scenario C — Wet carrier
A carrier arrives dripping. Stop, PPE, contain, identify what can be salvaged, clean, notify, document, recollect as needed.

Scenario D — System outage
PTS offline hospital-wide. Activate downtime hand-carry for STATs; do not queue critical samples in a dead station.

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Link to Practice

/practice/ascp-mlaPractice questions with detailed explanations

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Key Takeaways

• PTS is a privilege limited by policy, not a default for every container.
• Pack for impact: sealed primary, absorbent, biohazard bag, foam, latched carrier.
• CSF, some blood bank products, and certain pathogen-risk materials are often hand-carry only.
• Spills/crashes require PPE, containment, disinfection, notification, documentation.
• Downtime means immediate alternate transport, especially for STATs.