Management of a Chest Drain System
Role of Pleural Membrane
Outside Membrane of lungs = Visceral Pleura
2 membranes separated by a lubricating fluid (Pleural fluid), allows them to slide against each other
Inside membrane of rib cage = Parietal Pleura
-ve Pressure in the pleural space keeps the 2 pleurae together
Boyles Law
pressure is inversely proportional to its volume
Movement of Gases
Diffuse from area of higher pressure to lower pressure until they =
Atmospheric Pressure
Pressure higher than atmospheric pressure = + pressure
Pressure lower than atmospheric pressure = - pressure
= 760mmHg
Mechanics of Inspiration
Diaphragm contracts down, ribs extend up & out. Air is drawn in. - pressure between pleurae = -8cmH2O
Lung capacity is enlarged, intrapulmonary pressure becomes lower than atmospheric pressure & air is pulled into the lungs
Mechanics of Expiration
Diaphragm relaxes, pushes air out. - pressure between pleurae = -4cmH2O
Lung capacity decreases in volume, intrapulmonary pressure becomes greater than atmospheric pressure & air is forced out of the lungs
Conditions Requiring Chest Drainage
Haemothorax
Haemopneumothorax
Pneumothorax
Empyema
Tension pneumothorax
Pleural Effusion
Surgery: lobectomy, pneumonectomy
Chest Drain Insertion
To remove liquids/ gases from the pleural space & restore normal resp. function
Insertion site = 2nd-3rd ICS (site for air only) or 8th-9th ICS (site for mostly fluid)
To re-expand lung & restore - pressure within the pleura & restore normal resp. function
Water Sealed Chest Drain
Works using, expiratory + pressure, gravity, suction
Water Seal: Single Bottle System-
chest drain from pt. is placed 2cm below H2O level.
On exhalation a rise in intrapleural pressure in excess of 2cm of H2O will push air out through tube (air can't return due to H2O seal)
Can be used to collect fluid as well as air from pleura, but as fluid rises the H2O seal (2cm) becomes more difficult to expel air.
Works on gravity
2 Bottle System: allows separate collection chamber & H2O seal
3 Bottle System: suction control chamber added. If 20cm of H2O is added to suction control bottle, the suction applied to the pt. is -20cm H2O even if the vacuum source indicates a higher level of suction. 3 chambers = suction control, H2O seal, fluid collection
Fluid Collection Chamber
Colour of fluid should get lighter & pinker over time. Thick sticky yellow/green fluid = ?infection. Take sample via sample port in chest tube
Markings will show amount of fluid loss over time. Immediately post-op blood loss = very bloody, later serous.
Monitor & record fluid hourly/ daily- noting colour consistency & amount over time
Water Seal Chamber
Amount of water= fill & maintain H2O seal @ 2cmH2O using front face grommet.
Bubbling= bubbling on expiration indicates there's still air in pleural space & chest drain system is patent & functioning. Excessive bubbling from R>L = air leak in system. (sources: insertion site, chest drain pulled out, poor connection between trocar & cannula).
No bubbling = tube blockage or re-inflation of lungs
Monitoring Intrapleural - pressure: observe float ball as pt. breathes in + out. Reflects pressure within 2 layers of pleural membrane. If - pressures rise too much = ball will float to the top & trigger a release valve allowing H2O out of the chamber
Reading intrapleural - pressure:
On Gravity = float ball rises & falls on inspiration & expiration. Intrapleural pressure read directly from H2O seal chamber scale. Any rise in H2O seal float ball indicates - pressure is present.
Within suction chamber on: add readings of suction control chamber + level of H2O seal chamber.
-20cmH2O (SC) + -5cmsH2O 9WSC) = -25cmH2O intrapleural pressure
Suction Control Chamber
Bubbling: constant gentle bubbling is normal. No bubbling in suction control chamber = not enough suction applied to drawn air in from atmosphere or it's disconnected from the vacuum.
DON'T turn suction control stopcock during gravity drainage: could cause tension pneumothorax
Level of H2O: suction control chamber is atmospherically vented & filled with specific amount of H2O prescribed (max. 20cmsH2O). Adding/removing H2O to suction content chamber controls the amount of suction imposed on the pt. Amount of water not the level of vacuum applied that determines level of suction control
+ve pressure release valve: if suction line is occluded or turned off & there's a build up of + pressure it will automatically be released through the valve. Prevents tension pneumothorax during accidental suction line occlusion
Potential Problems
Chest drain clamps
Chest drain must be below level of pt. heart
Floor stand not fully open/ used
Overfilled H2O seal > 2cm
Partial disconnection of chest tube
Dislodgement from pt. chest
Kink in tubing
Clot in/ outside chest tube of pt.
Removal
Clamp chest drain & remove
Tie off purse string, suture, apply dressing
Repeat CXR
PT. performs valsalva manoeuvre
Remove sutures 10-12 days
Remove dressing & loosen purse string suture
CXR = ensure expansion