7.3 Chest Tube Management, Pleural Drains & Tension Pneumothorax

Chest Tube Management, Pleural Drains & Tension Pneumothorax

In critical care transport, managing pleural drainage systems and maintaining thoracic decompression are essential skills. Transport clinicians must rapidly identify pleural space emergencies, operate three-chamber drainage units, troubleshoot air leaks, and safely transport patients with chest tubes.

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Indications for Thoracic Drainage

Thoracostomy (chest tube placement) is indicated to evacuate abnormal accumulations of air, blood, or fluid from the pleural space, restoring negative intrapleural pressure and re-expanding collapsed lung tissue:

• Pneumothorax: Simple, tension, or open pneumothorax.
• Hemothorax: Accumulation of blood. Massive hemothorax is defined as initial output $> 1,500 \text{ mL}$ upon insertion, or continuous bleeding $> 200 \text{ mL/hr}$ for $2-4 \text{ hours}$, indicating the need for emergent surgical thoracotomy.
• Pleural Effusion / Empyema: Transudative/exudative fluid or purulent infection.

Tube Sizing Selection

• Small-Bore ($14-20 \text{ Fr}$): Air evacuation (spontaneous or simple pneumothorax).
• Large-Bore ($28-36 \text{ Fr}$): Hemothorax, thick exudative effusions, or empyema to prevent clot obstruction.

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Operation of the Three-Chamber Pleural Drainage System

Modern closed-chest drainage systems (e.g., Atrium, Pleur-evac) utilize a three-chamber concept to evacuate air/fluid while preventing atmospheric backflow.

           ┌────────────────────────────────────────────────────────┐
           │          THREE-CHAMBER CHEST DRAIN SYSTEM              │
           └────────────────────────────────────────────────────────┘

  Patient Tube ───> ┌──────────────┐   ┌──────────────┐   ┌──────────────┐
                    │ Collection   │──>│  Water Seal  │──>│   Suction    │──> To Suction
                    │   Chamber    │   │   Chamber    │   │   Control    │    Source
                    │ (Measures Vol)│  │ (2 cm Water) │   │(-20 cmH2O)   │
                    └──────────────┘   └──────────────┘   └──────────────┘

1. Collection Chamber

• Connects directly to the patient's chest tube.
• Collects fluid, blood, or exudate; calibrated for precise hourly volumetric measurement.

2. Water Seal Chamber

• Functions as a one-way valve: allows air and fluid to exit the pleural space during exhalation but prevents outside air from re-entering during inspiration.
• Filled with sterile water to the $2 \text{ cm}$ mark.
• Contains an integrated Air Leak Meter calibrated from 1 (low) to 5 (high).

3. Suction Control Chamber

• Regulates the level of negative pressure applied to the pleural space.
• Wet Suction Systems: Suction level is dictated by the height of the water column (typically filled to $-20 \text{ cmH}_2\text{O}$). Gentle, continuous bubbling indicates active suctioning.
• Dry Suction Systems: Utilizes a mechanical rotary dial setting (set to $-20 \text{ cmH}_2\text{O}$) and a spring-loaded bellows indicator.

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Water Seal Chamber Interpretation & Troubleshooting

Systematically Locating an External Air Leak

If continuous bubbling occurs in the water seal chamber, systematically isolate the leak:

1. Momentarily Clamp near Chest Wall: Apply a padded clamp to the chest tube close to the patient's skin insertion site.
   • If bubbling stops: The air leak originates from inside the patient's lung/pleural space.
   • If bubbling continues: The air leak is located in the tubing or connection points below the clamp.
2. Move Clamp Down Tubing: Stepwise clamp downwards toward the drainage unit to identify cracked connectors or loose fittings.

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Tension Pneumothorax: Clinical Diagnosis & Decompression

Tension pneumothorax develops when a one-way valve effect permits air entry into the pleural space during inspiration but prevents egress during expiration. Intrapleural pressure rapidly exceeds atmospheric pressure, causing total lung collapse, mediastinal shift to the contralateral side, compression of the vena cava, and severe obstructive shock.

Clinical Manifestations

• Severe, progressive respiratory distress and tachypnea.
• Hemodynamic Collapse: Hypotension, severe tachycardia, cool/clammy skin.
• Unilateral Absent Breath Sounds and hyperresonance to percussion over affected hemithorax.
• Jugular Venous Distension (JVD) (may be absent in hypovolemic trauma patients).
• Tracheal Deviation away from the affected side (late, insensitive sign).
• In Ventilated Patients: Sudden spike in Peak Inspiratory Pressure ($P_{peak}$), drop in tidal volume, rapidly falling $SpO_2$, and sudden PEA cardiac arrest.

               Tension Pneumothorax Pathophysiology

        Intrapleural Air Accumulation (Positive Pressure)
                               │
                               ▼
          Mediastinal & Tracheal Shift to Contralateral Side
                               │
                               ▼
         Compression of Superior & Inferior Vena Cava
                               │
                               ▼
           Preload Drop ---> Obstructive Shock ---> PEA Arrest

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Needle Decompression Anatomical Sites

Needle decompression converts a tension pneumothorax into an open simple pneumothorax. A minimum 14-gauge or 12-gauge, 3.25-inch (8 cm) catheter must be used.

Procedure Note: Always insert the needle directly OVER THE TOP OF THE LOWER RIB to avoid injuring the intercostal neurovascular bundle running along the inferior margin of the rib.

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Finger Thoracostomy in Transport

In intubated, positive-pressure ventilated trauma patients with suspected tension pneumothorax, finger thoracostomy is superior to needle decompression:

1. Make a $2-3 \text{ cm}$ skin incision at the 4th/5th intercostal space, anterior axillary line.
2. Perform blunt dissection through subcutaneous tissue and intercostal muscle layers using curved Kelly forceps over the superior border of the 5th rib.
3. Pop through the parietal pleura, open the forceps, and insert a gloved finger directly into the pleural space.
4. Sweep $360^\circ$ with the finger to clear adhesions, evacuate trapped air and blood, and confirm intrapleural position before inserting a chest tube.

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Critical Transport Safety Rules

Rule 1: NEVER Clamp a Chest Tube During Transport

• CRITICAL MANDATE: Chest tubes must NEVER be clamped during transport!
• Rationale: If a patient has an active parenchymal lung leak, clamping the chest tube traps air inside the pleural cavity, rapidly converting a simple pneumothorax into a fatal tension pneumothorax.
• Exceptions: Clamping is permissible ONLY for a few seconds when changing the drainage collection unit or systematically locating an external air leak.

Rule 2: Drain Positioning

• Always keep the drainage unit upright and positioned below the level of the patient's chest (e.g., secured to the lower stretcher frame) to allow gravity drainage and prevent fluid backflow.

Rule 3: Accidental Disconnection Protocol

• If Chest Tube Disconnects from Drainage Unit: Submerge the distal tip of the chest tube $2-4 \text{ cm}$ deep into a bottle of sterile water or sterile saline. This immediately re-establishes a water seal valve while a new drainage unit is prepared.
• If Chest Tube Pulls Completely Out of Chest Wall: Immediately apply a sterile three-sided occlusive dressing (e.g., Asherman Chest Seal or petrolatum gauze taped on three sides). This creates a flutter valve allowing air to escape during expiration while preventing entry during inspiration. Monitor closely for tension pneumothorax development.

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